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BRITISH JOURNAL OF OPHTHALMOLOGY

Myopic choroidal neovascularisation
Reviewed by: Jonathan Chan
Vol 22 No 2
 

This is a review article summarising the latest myopic CNV (choroidal neovascularisation) literature in the clinical experience and management outcomes for recommendation algorithm. The aetiology of the myopic CNV was discussed by the authors under the heading of the heredo-degenerative and haemodynamic theories for the development of myopic CNV. The diagnosis of myopic CNV was based on the clinical examination, including fundal biomicroscopy, fluorescein angiogram and optical coherence tomography (OCT). The majority of the myopic CNV presents as a classic pattern on the fluorescein angiogram. On OCT imaging the majority represents a highly refractive area above the retinal pigment epithelium – type 2 CNV with minimal subretinal fluid. Fundus autofluoresence showed the increase in the accumulative lipofuscin within the retinal pigment epithelium. Lucentis (ranibizumab) is the only licensed anti-VEGF therapy for treatment of myopic CNV. Avastin (bevacizumab) is not approved for intraocular use and evidence on its safety and efficacy profile is limited. Aflibercept (Eylea) for myopic CNV is undergoing phase III, multicentre, randomised trial at present. Recent reports on Eylea indicate sustained best corrected visual acuity gains of up to 12 months. The authors recommend a treatment algorithm for myopic CNV. After initial assessment prompt treatment with a single intravitreal injection of anti-VEGF therapy is recommended due to the superior efficacy of anti-VEGFs over other treatment modalities. After the initial injection, the patients will be monitored monthly for months one and two and then at least three-monthly in the first year. If patients have positive activity or visual loss then they will have a repeat injection. After one year, the monitoring frequency should be established by the retinal specialist in consultation with the patient and the patient should be advised to return if they experience any drop in vision.

Reference

Myopic choroidal neovascularisation: current concepts and update on clinical management.
Wong TY, Ohno-Matsui K, Leveziel N, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2015;99:289-96.

BRITISH JOURNAL OF OPHTHALMOLOGY

Screening for ROP using wide-angle digital retinal photography by non-ophthalmologists
Reviewed by: Jonathan Chan
Vol 22 No 2
 

This is a systematic review article to evaluate the accuracy of digital retinal photography (DRP) performed by trained personnel (non-ophthalmologists) in diagnosing clinically significant retinopathy of prematurity (ROP). The authors used search engines including Medline, EMBASE, CINAHL and Cochrane databases. There were in total six studies within the inclusion criteria (three prospective; N=120, three retrospective, N=579). All the eligible studies were assessed using the quality assessment of diagnostic accuracy (QUADAS)-2, an evidence-based tool for the assessment of the quality in systematic reviews of diagnostic accuracy studies. Because of the heterogeneity of the studies, data could not be pooled to derive single-effect size estimates for sensitivity and specificity. However, the included studies reported sensitivity of 45.5-100% with the majority being more than 90%; specificity 61.7-99.8% with the majority being more than 90%, positive predictive value was 61.5-96.6% and negative predictive value was 76.9-100% for diagnosing clinically significant ROP. The authors concluded that the ROP imaging diagnostic accuracy must be established in a larger sample size in prospective multicentre trials where the ROP is compared simultaneously against the performed reference of standard binocular indirect ophthalmoscopy examination.

Reference

Screening for retinopathy of prematurity (ROP) using wide-angle digital retinal photography by non-ophthalmologists: a systematic review.
Athikarisamy SE, Patole S, Lam GC, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2015;99:281-8.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Choroidal and RNFL thickness in patients with OSAS
Reviewed by: Anjali Gupta
Vol 22 No 2
 

In obstructive sleep apnoea syndrome (OSAS), hypoxia secondary to repetitive apnoeic episodes leads to blood pressure variations and haemodynamic changes. There is also intermittent activation of the sympathetic system when the patient is aroused from sleep during apnoeic episodes. OSAS is known to be associated with many ophthalmological disorders such as floppy eyelid syndrome, glaucoma, non arteritic ischaemic optic neuropathy, central serous chorioretinopathy and papilloedema. However, little is known about the effects of OSAS on the choroid, one of the most vascularised tissues in the body. The aim of this study was to compare the choroidal thickness (CT) and retinal nerve fibre layer (RNFL) thickness in patients with OSAS to healthy controls. Ninety-two eyes of patients with OSAS and 32 eyes of age and body mass index (BMI) matched healthy controls were included in this study. OSAS patients were further divided into mild, moderate and severe groups according to their apnoea hypopnea index (AHI) values. All patients and controls were imaged with the RTVue SD-OCT system from 10am to 12am after pupil dilation. Measurements were taken for peripapillary RNFL thickness and macular CT and compared between groups. Results showed that the severe OSAS group had significantly thinner CT than the mild OSAS group at 3mm nasal to the fovea. The control group had significantly thicker CT 1.5mm and 3mm nasal to the fovea compared with the severe OSAS group. The severe and moderate OSAS groups had significantly thinner nasal RNFL measurements than controls. The severe OSAS group also had significantly thinner superior RNFL measurements than the controls. The authors conclude that patients with OSAS have choroidal structural alterations that may have significance on the pathophysiology of the ophthalmic disorders associated with OSAS.

Reference

Evaluation of the macular choroidal thickness using spectral optical coherence tomography in patients with obstructive sleep apnea syndrome.
Bayhan HA, Bayhan SA, Intepe YS, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2015;43:139-44.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Twenty-four hour IOP patterns in patients with thyroid eye disease (OO/GL)
Reviewed by: Anjali Gupta
Vol 22 No 2
 

Elevated IOP in patients with thyroid eye disease (TED) can be caused by restriction and compression of the globe by enlarged extraocular muscles, elevated episcleral venous pressure and increased mucopolysaccharide deposition in the trabecular meshwork. Although previous studies have investigated the relationship between IOP and TED, there have been no previous studies that have evaluated the 24-hour IOP rhythms in patients with TED. The purpose of this study was to evaluate the safety and tolerability of a contact lens sensor (CLS) to measure IOP in patients with TED and to describe the 24h IOP patterns in this group of patients. The CLS is a high oxygen permeable soft contact lens with an embedded microprocessor which can measure IOP. The device is based on the approach that changes in corneal curvature and circumference are assumed to correspond to changes in IOP. An advantage of the CLS is that 24 hour IOP measurements can be taken in ambulatory conditions and undisturbed sleep. Ten patients with TED had the CLS placed on one eye for 24 hours. Study patients kept an activity diary for half hourly information of their activity, such as sleep, meals, physical activity. Results showed adverse events associated with the CLS included mild blurred vision (50%), mild hyperaemia (100%) and superficial punctate keratitis (20%). All adverse events were transient and resolved after CLS removal. Overall, when evaluating the whole study group, this model showed a nocturnal / sleep acrophase, with the peak occurring at 06:30hrs. Specifically, 50% of patients had a significant nocturnal / sleep acrophase, 20% had a significant diurnal acrophase, and 30% had no significant acrophase. The authors conclude that the CLS is a safe and well tolerated device in patients with TED and patients with TED are most likely to have a morning acrophase.

Reference

Twenty-four hour intraocular pressure patterns in patients with thyroid eye disease.
Parekh AS, Mansouri K, Weinreb RN, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2015;43:108-14.

CURRENT EYE RESEARCH

Air toxicity on retinal pigment epithelium
Reviewed by: Khadijah Basheer
Vol 22 No 2
 

This study investigated the potential toxic effects of air on primary human retinal pigment epithelial (RPE) cells in vitro. Clinically during pars plana vitrectomy air is used as either a temporary tamponade during air-fluid exchange or mixed with gas to provide an internal tamponade in the postoperative period lasting several days or weeks. The study showed that the RPE cells revealed large deformities after six hours of air exposure. They observed a more flattened, hypertrophic shape and a decrease in cell viability after 12 hours of exposure. Although during retinal surgery the RPE is not directly exposed to air, other animal studies have reported toxicity to the inner limiting membrane, nerve fibre layer and retinal ganglion cells. The obvious limitation to this study is that the model was not dynamic and not in vivo, however, it showed similar results to animal studies using cell culture models. Further studies are necessary in order to fully explore and apprehend the possible toxic effect of air on human retinal epithelium.

Reference

The toxic effect of air on primary human retinal pigment epithelium cells.
Kopsachilis N, Carifi G, Tsatsos M, et al.
CURRENT EYE RESEARCH
2015;40(6):555-60.

EXPERIMENTAL EYE RESEARCH

Transfected RPE cells inhibit AMD in rats
Reviewed by: Graham Wallace
Vol 22 No 2
 

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. Wet AMD is characterised by choroidal neovascularisation, new vessels into the retina, leading to leakage and tissue damage. Many proangiogenic factors particularly vascular endothelial growth factor (VEGF) are fundamental to neovascularisation as shown by several drugs that block this pathway being used in AMD treatment. Fibulin-5 (Fbln5) is a matrix glycoprotein expressed in the retina and mutations in Fbln5 gene have been associated with increased risk of developing AMD. Fbln5 is an inhibitor of VEGF, a function that may explain the genetic data. In this paper retinal pigment epithelium cells were transfected with a lentivirus construct containing the FBln5 and GFP, such that the resultant cells overexpressed the protein and were green on fluorescence microscopy. CNV was induced by laser photocoagulation in rats and Fbln5-transfected RPE cells or RPE cells with the same construct, minus FBLn5, were injected into the subretinal space of the right and left eyes respectively. Transplanted RPE cells survived for at least four weeks, and eyes with Fbln5 overexpressing RPE cells showed a significantly smaller area of leakage and number of leakage spots compared to eyes transfected with control RPE cells. Growth and injection of RPE cells cultivated in vitro show promise for the treatment of AMD. This study demonstrates that manipulation of RPE cells prior to delivery to the eye can enhance the effect of such cells and provides a new area of research to define which genes will give the best results. This may depend on the potential to make stable contrasts to avoid continuous treatment, but the concept shown is important.

Reference

Subretinal transplantation of retinal pigment epithelium overexpressing fibulin-5 inhibits laser-induced choroidal neovascularisation in rats.
Li F, Zeng Y, Xu H, Yin ZQ.
EXPERIMENTAL EYE RESEARCH
2015;136:78-85.

INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

Sustained elevation of extracellular ATP in chronic glaucoma
Reviewed by: Wai Siene Ng
Vol 22 No 2
 

Although adenosine 5′-triphosphate (ATP) release from retinal neurons and astrocytes has been demonstrated in short-term increases in intraocular pressure (IOP); such as in aqueous humor of humans with primary acute angle closure glaucoma, the response in chronic IOP elevation was not yet demonstrated and this group set out to investigate this in three different chronic glaucoma models (Tg-MyocY437H mice, rats with hypertonic saline injection into episcleral veins and monkeys with laser photocoagulation to the trabecular meshwork). They found increased levels of ATP in vitreal humor of all three models. Although contamination of intracellular ATP from cell rupture can occur, the group proceeded to further confirm this rise by measuring NTPDase1; an ectoenzyme which dephosphorylates ATP. This paper makes a good start at supporting the purinergic signalling pathway disturbance is sustained in glaucoma, suggesting a longer target window may be available for therapeutic rescue.

Reference

Rat, mouse and primate models of chronic glaucoma show sustained elevation of extracellular ATP and altered purinergic signalling in the posterior eye.
Lu W, Hu H, Sevigny J, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2015;56:3075-83.

INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

The impact of conjunctivochalasis on dry eye symptoms and signs
Reviewed by: Wai Siene Ng
Vol 22 No 2
 

The study aimed to draw a relationship between conjunctivochalasis and dry eye symptoms via a dry eye questionnaire (DEQ5), as well as signs such as tear osmolarity, tear break up time, corneal staining, Schirmer score, meibomian gland dropout, eye lid vascularity and meibum quality. The authors conclude that the presence of a nasally located conjuntivochalasis was associated with the most severe symptoms and signs. However, contrary to this, patients with no conjunctivochalasis had similar DEQ5 scores as patients with nasal conjunctivochalasis. Previous studies performed in China and Germany found increased dry eye symptoms in patients with nasal conjunctivochalasis. This study extends this by reporting a similarity in results for an American population. This paper is unique in that its patient cohort was a predominantly male population; an understudied population in dry eyes.

Reference

The impact of conjunctivochalasis on dry eye symptoms and signs.
Chhadva P, Alexander A, McClellan A, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2015;56:2867-71.

JOURNAL OF REFRACTIVE SURGERY

Influence of FLEx and SMILE on corneal nerve density and ocular surface
Reviewed by: Mrinal Rana
Vol 22 No 2
 

This was a prospective study designed to compare the influence of femtosecond lenticule extraction (FLEx) and small incision lenticule extraction (SMILE) on the corneal nerve density and ocular surface for myopic correction. Thirty patients underwent bilateral lenticule extraction. One eye was randomly picked for FLEx and the other had SMILE. Inclusion criteria included unsatisfactory visual acuity even with spectacle or contact lens correction, myopic refractive error ranging between -1 to -9D, corneal thickness >400mic and residual stromal bed of 250microns. Surgical procedure for FLEx and SMILE involved use of VisuMax femtosecond laser system with 500KHz repetition rate. The incision pattern followed an automated sequence of posterior surface of lenticule, then anterior surface of lenticule and side cut flap. After completion of laser sequence for FLEx the flap was lifted, lenticule grasped and extracted. The flap was repositioned and interface flushed and for SMILE, the spatula was inserted through the side cut over and under the lenticule to free it from its adhesions and then grasped and pulled out. Sub-basal nerve density was measured using confocal microscope (HRT3 Rostock Cornea Module, Heidelberg Engineering GmbH) at one week, one and three months and one year postoperatively. Ocular surface parameters like Schirmer test, tear film break up time and corneal sensations were also performed pre and postoperatively at one and three months. The results were significantly favouring the SMILE correction with sub-basal nerve density postoperatively at 11,870±8200 microns/mm² compared to 5770±3490 microns/mm² with FLEx. The ocular surface parameters were found to be significantly reduced, when FLex was compared with SMILE. This supports further the reduction in the sub-basal nerve density. The limitations of the study were low number sample size and lack of impression cytology to look at conjunctival goblet cells and their effect on ocular surface parameters. These results do add further to evidence that prove that SMILE is better than FLEx when treating myopia in a minimally invasive fashion.

Reference

Influence of femtosecond lenticule extraction and small incision lenticule extraction on corneal nerve density and ocular surface: A 1 year prospective, confocal, microscopic study.
Ishii R, Shimizu K, Igarashi A, et al.
JOURNAL OF REFRACTIVE SURGERY
2015;31(1):10-5.

NEURO-OPHTHALMOLOGY

A case of progressive supranuclear palsy-like syndrome following aortic aneurysm repair
Reviewed by: Claire Howard
Vol 22 No 2
 

This original article illustrates the case of an 18-year-old woman who developed progressive supranuclear palsy-like syndrome following an uneventful aortic aneurysm repair. The patient was unaffected for the first 48 hours after surgery and then developed dysarthria, dysphagia (requiring a gastric tube), emotional lability and ophthalmoplegia. The authors have provided a video of the patient to illustrate how profound these deficits were. The patient underwent extensive contrasted fat suppressed cranial and orbital MRI, MRI tractography and functional MRI. Given the extensive degree of neurological impairment, the authors expected this advanced neuroimaging to be abnormal, however, it revealed no clear radiographic involvement, except for a tiny hypoechoic midbrain dot which is not considered sufficient to account for the patient’s deficits. This case attests to the unknown and unusual nature of this rare and devastating syndrome.

Reference

Functional magnetic resonance imaging (MRI) and MRI tractography in progressive supranuclear palsy-like syndrome.
Vaphiades MS, Visscher K, Rucker JC, et al.
NEURO-OPHTHALMOLOGY
2015;39(2):64-8.

NEURO-OPHTHALMOLOGY

A case series of acquired esotropia in cerebellar disease
Reviewed by: Claire Howard
Vol 22 No 2
 

Acquired esotropia in cerebellar disease is well described but under-recognised. The pathogenesis of cerebellar esotropia is controversial. It is suggested it may be a result of disruption to central vestibular pathways. This article reports a case series of seven adults with diplopia secondary to cerebellar dysfunction. The authors describe a deterioration of cerebellar esotropia over time. This has not previously been reported. All the patients were initially diagnosed with lateral rectus paresis, the diagnosis being revised after examination showed no slowing of abducting saccades and full abduction with gaze evoked nystagmus. The authors aim was to demonstrate that diplopia due to cerebellar esotropia can be the first manifestation of the underlying disorder and as such the condition may be misdiagnosed. This is something for clinicians to bear in mind when assessing patients with newly acquired symptoms.

Reference

Acquired esotropia in cerebellar disease: a case series illustrating misdiagnosis as isolated lateral rectus paresis and progression over time.
Wong SH, Patel L, Plant GT.
NEURO-OPHTHALMOLOGY
2015;39(2):59-63.

NEURO-OPHTHALMOLOGY

A case series of acute visual loss following excessive alcohol and / or drug use
Reviewed by: Claire Howard
Vol 22 No 2
 

This study presents three cases of so called Saturday night retinopathy, an acute visual loss following intravenous drug abuse and stupor, leading to continuous pressure on the orbit while asleep. All three cases presented with acute vision loss and had funduscopic evidence of ophthalmic or central retinal artery occlusion. Two of the cases also presented with ophthalmoplegia and proptosis. One of the cases had significantly increased intraocular pressure and corneal oedema. All three cases had poor visual outcomes with severe visual loss in the affected eye and no recovery. The authors detail the cases with photographs and imaging and discuss the possible causes for this finding. It is thought that prolonged periods of altered mental state inhibit spontaneous movement, which would normally alleviate the focal compression during normal sleep. Unfortunately no treatment has proven to be of any benefit.

Reference

Saturday night retinopathy with ophthalmoplegia: a case series.
Malihi M, Turbin RE, Frohman LP.
NEURO-OPHTHALMOLOGY
2015;39(2):77-82.

NEURO-OPHTHALMOLOGY

Neuro-ophthalmological symptoms in patients with cerebral venous sinus thrombosis
Reviewed by: Claire Howard
Vol 22 No 2
 

The authors of this article have evaluated the neuro-ophthalmological symptoms of 49 patients with cerebral venous sinus thrombosis. They have evaluated the onset of the disease as well as the symptoms reported. The authors present extensive clinical information for individual cases including clinical presentation, treatment and overall outcome. Patients present with signs of intracranial hypertension, with papilloedema being one of the most frequent findings. Papilloedema was revealed in 84.6% of patients with acute and subacute onset and in all patients in the chronic phase of onset. Patients with acute onset of cerebral venous sinus thrombosis were successfully treated with local endovascular thrombolysis. Patients with chronic onset, where visual disturbance was present, required lumboperitoneal shunting to prevent any further loss of vision. The article highlights the outcome of treatment for varying stages of onset, this should be considered when planning management for this patient group.

Reference

Neuro-ophthalmological features of cerebral venous sinus thrombosis.
Eliseeva N, Serova N, Yakovlev S, et al.
NEURO-OPHTHALMOLOGY
2015;39(2):69-76.

NEW ENGLAND JOURNAL OF MEDICINE

Persistence of Ebola virus in ocular fluid during convalescence
Reviewed by: Jonathan C P Roos
Vol 22 No 2
 

The most recent Ebola outbreak has infected over 26,300 patients, but also resulted in the highest number of survivors in history. Uveitis has been described during the convalescent period, but Varkey and colleagues report, for the first time, finding viable Ebola virus in the aqueous fluid of a 43-year-old male doctor nine weeks after clearance of viraemia. At this point a patient would ordinarily no longer be considered infectious. The patient had been treated with an experimental small RNA interfering agent, as well as convalescent plasma (blood product from an Ebola survivor) and supportive care for multi-organ failure including ventilation and haemodialysis. After a protracted ICU stay his blood and urine tested negative for virus and he was discharged home. Interestingly, as his semen continued to test positive for virus, he was advised to abstain from sex or to use condoms for at least three months. This is noteworthy as the gonads are an immune-privileged site alongside the eye, brain and articular cartilage. After discharge, the patient, who had no previous ocular history, began to complain of symptoms of uveitis and a foreign body sensation. Repeat examinations revealed stable bilateral chorioretinitis but a marked anterior chamber reaction and elevated IOP of 44mmHg then developed. Topical prednisolone drops resulted in a rapid deterioration and an aqueous tap revealed viable Ebola virus. Reassuringly, a conjunctival swab and tear film fluid were negative. The patient continued to deteriorate with marked scleritis and uveitis. The marked vitritis was treated with periocular triamcinolone, oral faviparivir and oral steroids. After six weeks the patient had recovered. The authors concluded that this panuveitis was due to the direct cytopathic effect associated with viral replication as this has previously been seen with Marburg virus. This case demonstrates that the eye can act as a reservoir of infection for Ebola which has significant implications for all clinicians. Ophthalmologists should take extra precaution during ocular examinations and procedures in patients suspected of having, or who have recovered from, Ebola virus.

Reference

Persistence of Ebola virus in ocular fluid during convalescence.
Varkey JB, Shantha JG, Crozier I, et al.
NEW ENGLAND JOURNAL OF MEDICINE
2015;372:2423-7.

OCULAR IMMUNOLOGY AND INFLAMMATION

Allografts in limbal stem cell deficiency
Reviewed by: Saruban Pasu
Vol 22 No 2
 

This prospective comparative study compared outcomes of live related limbal allograft (Lr-CLAL) versus cadaveric keratolimbal allograft (KLAL) in limbal stem cell deficiency secondary to ocular burns. Twenty patients were randomly allocated into each group. The Lr-CLAL group had a significant decrease in conjunctivalisation, improved tear break up time and increase in Schirmer’s values at six month follow-up. Three eyes had either persistence or increase in conjunctivalisation after three months in the Lr-CLAL group, compared to eight eyes in the KLAL group. There were no intraoperative complications. Significant visual improvement was seen in 8/10 patients in the Lr-CLAL group and 5/10 in the KLAL group. There was a statistically significant difference between the two groups at six months follow-up. Corneal clarity was better maintained in the Lr-CLAL group. This study suggests that live related allograft may provide better visual and anatomical outcomes than keratolimbal allograft for management of limbal stem cell failure secondary to chemical or thermal burns.

Reference

Live related versus cadaveric limbal allograft in limbal stem cell deficiency.
Titiyal J, Sharma N, Agarwal A, et al.
OCULAR IMMUNOLOGY AND INFLAMMATION
2015;23(3):232-9.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Botulinum toxin after orbicularis myectomy
Reviewed by: James Hsuan
Vol 22 No 2
 

This is a retrospective review of 27 patients with benign essential blepharospasm who had become resistant to treatment with botulinum toxin and had therefore undergone orbicularis myectomy of the upper lids. The study compares the dose and frequency of botulinum toxin treatment before and after the myectomy procedure. Three patients needed no further botulinum toxin injections, and the remaining patients required a significantly smaller dose to the upper lids to achieve the same effect compared with their pre-surgery regimens. Furthermore the frequency of injections was also significantly less, reducing from every 10.1 weeks to every 15.7 weeks on average. The authors assessed the cost implications based on Medicare data and found that patients undergoing surgery cost over $11,000 less to treat over a 10 year period than those who persisted with injections alone. This is an interesting paper supporting the use of myectomy for blepharospasm patients who become resistant to botulinum toxin. The vast majority of patients still require on-going injections, but less frequently and with a smaller dose. It would be interesting to know if the same was true in non-resistant patients. The authors do not mention any side-effects from the surgery, but do admit that a weakness of their study was that a formal assessment of patient satisfaction was not performed. Other confounding factors are the simultaneous ptosis surgery and the subjective criteria to determine the efficacy of the botulinum toxin treatment. Despite these weaknesses, the study provides useful evidence for the efficacy and cost-effectiveness of myectomy surgery.

Reference

Effect of upper eyelid myectomy on subsequent chemodenervation in the management of benign essential blepharospasm.
Kent TL, Petris CK, Holds JB.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:222-6.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Conjunctival melanoma involving the lacrimal drainage system
Reviewed by: James Hsuan
Vol 22 No 2
 

A total of 52 patients were diagnosed with conjunctival melanoma over a period of 17 years, 17 of whom required orbital exenteration. Five of these were found to have melanoma involving the lacrimal drainage apparatus (LDA). One was evident clinically prior to exenteration, one was found to have sac involvement during exenteration, and another was discovered only on histological examination post-exenteration. The two remaining cases developed recurrent disease in the lacrimal sac two to three years post-exenteration. The authors recommend sac and proximal duct excision as a routine during exenteration for conjunctival melanoma. This is a very interesting paper with a high rate of LDA involvement compared to previous reports. The authors speculate on the mechanism of spread to the lacrimal sac, but it is noteworthy that all patients had undergone a previous biopsy of the lesion, and many had multiple previous resections. The risk of seeding of melanoma from biopsy or incomplete excision is well known, and this must be considered as a likely cause for the LDA spread. It is also of interest that the canaliculi were involved in only one patient. This reinforces the seeding hypothesis, and the message that histologically normal canaliculi should not reassure the surgeon that the sac or duct are definitely free of disease.

Reference

Malignant melanoma of the lacrimal drainage apparatus complicating conjunctival melanoma.
Satchi K, McKelvie P, McNab AA.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:207-10.

OPHTHALMIC RESEARCH

Cytotoxic effect of voriconazole on human corneal epithelial cells
Reviewed by: Bheemanagouda Patil
Vol 22 No 2
 

Voriconazole is a second-generation synthetic derivative of fluconazole with broadened antifungal spectrum. It is becoming the drug of choice for fungal keratitis. Voriconazole eye drops are not available commercially, thus have to be prepared by diluting the intravenous formulation containing 10mg of voriconazole and 160mg/ml sulfobutylether-β-cyclodestrin sodium (SBECD). SBECD is added to voriconazole to increase solubility, aqueous stability and bioavailability of the drug. The aim of this study was to assess the cytotoxic properties of various concentrations of voriconazole and SBECD on cultured primary human corneal epithelial cells (0.001–2mg/ml). No corneal epithelial cytotoxicity was observed below the concentration of 0.08 and 0.025mg/ml after 24-hour exposure to SBECD and voriconazole respectively. The results of this study reveal the dose-dependent cytotoxic effect of SBECD and voriconazole and thus they recommend that voriconazole eye drops should be used cautiously in the treatment of fungal keratitis.

Reference

Cytotoxic effect of voriconazole on human corneal epithelial cells.
Sobolewska B, Guerel G, Hofmann J, et al.
OPHTHALMIC RESEARCH
2015:54;41-7.

OPHTHALMIC RESEARCH

Topical atorvastatin for dry eye and blepharitis
Reviewed by: Bheemanagouda Patil
Vol 22 No 2
 

Dry eye is a very common problem with 20% of the population affected and is frequently associated with blepharitis (DEB), which has an over prevalence of about 40%. The aim of this study was to evaluate a topical atorvastatin formulation in a pilot study of DEB to assess the feasibility of a larger comparative trial. Ten DEB patients were enrolled in this prospective study. All patients were treated with topical atorvastatin (50µM) eight times daily for four weeks. They were allowed to continue their existing dry eye treatment. The primary outcome measure was corneal fluorescein staining. Secondary outcome measures were tear break up time (BUT), Schirmer testing, blepharitis score and bulbar conjunctival injection. An improvement in corneal fluorescein staining in the treated eye by >1 point from baseline to four weeks was seen in nine of 10 patients (p<0.01). Topical atorvastatin also significantly improved the tear break up time (p<0.01), blepharitis score (p<0.05) and bulbar conjunctival injection (p<0.05). There were no side-effects. They conclude that topical atorvastatin could be a potential therapy for DEB patients; however, larger comparative trials are needed to establish safety and efficacy.

Reference

Efficacy and safety of topical atorvastatin for the treatment of dry eye associated with blepharitis: a pilot study.
Ooi KG, Wakefield D, Billson FA, Watson SL.
OPHTHALMIC RESEARCH
2015;54:26-33.

OPHTHALMOLOGICA

Stereotactic radiotherapy for polypoidal choroidal vasculopathy
Reviewed by: Sofia Rokerya
Vol 22 No 2
 

Polypoidal choroidal vasculopathy (PCV) is a variant of neovascular AMD. It is a disease of choroidal vasculature characterised by abnormal branching vascular network with aneurysmal dilatations (polyps). Features of PCV include pigment epithelial detachments (PED), subretinal fluid (SRF) accumulation and haemorrhage. Indocyaninegreen angiography (ICGA) is essential for the identification of polyps. Anti-VEGFs are partially effective, as polyps persist and chronic exudation can lead to continued tissue destruction and permanent vision loss. PDT with verteporfin has been proven to stabilise visual acuity. Subretinal haemorrhage after PDT can occur and the efficacy of this treatment decreases over time. Radiotherapy has been proposed for the management of nAMD as it can induce regression of new vessels and inhibit both inflammation and fibrosis. However, this treatment can be accompanied by difficulties in accurate targeting and the inability to avoid collateral damage to surrounding tissues by dispersed energy. In this study the authors evaluate the results of a single centre, pilot study for 12 eyes of 12 patients enrolled with active PCV located in an area 4mm around the fovea, who were treated with 0.5mg ranibizumab and 16 GY X-ray SRT in a single session followed by prn intravitreal ranibizumab injections. The IRay System is an SRT device that generates x-rays from a low-voltage source. Narrow collimation of the beam, as well as immobilisation and real-time tracking of the eye motion, allow precise radiation delivery onto the macular target. The mean age of the patients included in this study (10 males and two females) was 70.01 ±6.04 years, and the mean axial length of the studied eyes was 23.05 ±0.9 mm. Nine of the 12 eyes were treatment naive; the other three eyes had previously received intravitreal bevacizumab injections. Eyes were evaluated for angiographic regression of polyps, improvement in visual acuity and central foveal thickness (CFT), at three, six and 12 months. At month three, choroidal polyps were no longer visible on ICGA in 10 of the 12 eyes. These 10 eyes (83.3%) maintained complete regression of polyps at month 12. At month 12, the mean BCVA improved from 65.08 ±11.4 to 72.7 ±14.75 ETDRS letters, 10 eyes had BCVA improvement, two gained >15 letters, and five eyes gained ≥10 letters. Two eyes had BCVA decreases (one and two letters, respectively). The mean CFT significantly decreased from 372.3 ±79.6μm at baseline to 215.9 ±57.9μm at month 12 (p value of the t test <0.01). The total mean number of intravitreal ranibizumab injections was 2.9 ±1.3 (range 1–5) and 3.9 ±2.5 (range 1–8) at months six and 12, respectively. No ocular or systemic adverse events or serious adverse events were observed during the study period. There were no signs of typical radiation-induced microangiopathy, such as microaneurysms, cotton wool spots and haemorrhage, on ophthalmoscopy or in the colour photographs. A limitation of the x-ray SRT device used in this study is the fixed nature of its irradiated spot, which is 4mm in diameter and centred on the macula, with no option to adjust its size or position. PCV may present as lesions variably located at the posterior pole and often at the peripapillary area, along the vascular arcades or in the temporal part of the retina – areas that are not treated by the SRT technology evaluated in this trial. In conclusion, the data from the pilot low-voltage x-ray SRT combined with intravitreal ranibizumab for the treatment of PCV showed that this therapy is safe and potentially effective, as indicated by the observed polyp closure, decreases in CFT and improvements in visual acuity of low-voltage x-ray SRT in the treatment of PCV.

Reference

Stereotactic radiotherapy for polypoidal choroidal vasculopathy.
Introini U, Casalino G, Triolo G, et al.
OPHTHALMOLOGICA
2015;233:82-8.

OPHTHALMOLOGY

Outcomes of ‘treat and extend’ for neovascular AMD
Reviewed by: Brian Ang
Vol 22 No 2
 

The authors report on 24-month outcomes of anti-vascular endothelial growth factor (anti-VEGF) therapy using a ‘treat and extend’ regime for treatment-naïve neovascular age-related macular degeneration (nAMD). Data for this study was collected from the Fight Retinal Blindness observational registry based in Australia and New Zealand. The treat and extend protocol involved initial treatment once every four weeks until the nAMD was no longer active. This was followed by extension of treatment interval by one to two weeks, provided the visual acuity was stable and there were no clinical or OCT signs of activity. Should there be recurrence of nAMD activity, the treatment interval was shortened again. In total, 1198 eyes of 1011 patients were included in the study. Ranibizumab monotherapy was received by 588 eyes (49%) while bevacizumab monotherapy was received by 25 eyes (2%). Five hundred and eighty-five eyes (49%) received a combination of bevaczumab, ranibizumab and aflibercept. Over the two year study period, the mean number of injections was 13 per eye (7.5 in the first year, and 5.5 in the second year). The mean number of visits was 14.8 (7.9 in the first year, and 6.7 in the second year). The endophthalmitis rate was 0.013% (one per 7272 injections). Visual acuity improved by a mean of 5.3 letters (from 56.5 at baseline to 61.8 at 24 months). The proportion of eyes achieving a vision of 6/12 increased from 27% at baseline to 45% at 24 months, while those with vision worse than 6/60 remained unchanged (13% at baseline; 11% at 24 months). Although there were quite a number of eyes that were lost to follow-up, this shows that ‘treat and extend’ for nAMD can achieve good visual outcomes in routine clinical practice and at the same time reduce the need for monthly clinic visits and injections.

Reference

Two-year outcomes of “treat and extend” intravitreal therapy for neovascular age-related macular degeneration.
Arnold JJ, Campain A, Barthelmes D, et al.
OPHTHALMOLOGY
2015;122:1212-9.

OPHTHALMOLOGY

Postural control in glaucoma patients with virtual reality
Reviewed by: Brian Ang
Vol 22 No 2
 

The authors report on a cross-sectional study evaluating postural control and history of falls in glaucoma patients. History of falls was obtained using the Falls Screening and Referral Algorithm. Postural stability was assessed using a force platform under four conditions: static condition, dark field without visual stimulation, rotational stimulation and translational stimulation. Visual stimulation was achieved with the Oculus Rift, a head-mounted stereoscopic goggles system that projects an immersive virtual environment for the wearer. Torque moments that are generated on the force platform due to a shift in the patient’s centre of gravity are measured as standard deviations of the torque moments (STD) in Newton metres (Nm). Forty-two glaucoma patients and 38 healthy controls participated in the study. As expected, the diagnosis of glaucoma was significantly associated with a history of falling. Significantly greater STD was found in glaucoma patients for static conditions (no stimulus) as well as translational and rotational stimuli. In glaucoma patients, falls were associated with only dynamic translational stimulation once multivariate analysis was performed taking into account age, body mass index, visual field defect severity and visual acuity. In healthy subjects, none of the postural metrics were associated with falls. Despite the limitations of the study (small sample size, musculoskeletal and vestibular tests not performed, falls not evaluated prospectively), this is an interesting paper describing a novel way of evaluating postural control in glaucoma patients.

Reference

Evaluation of postural control in patients with glaucoma using a virtual reality environment.
Diniz-Filho A, Boer ER, Carolina PBG, et al.
OPHTHALMOLOGY
2015;122:1131-8.

STRABISMUS

Binocular summation with low contrast
Reviewed by: Fiona Rowe
Vol 22 No 2
 

The magnitude of binocular summation was investigated in normal control subjects using four different letter charts of varying type with fixed and variable contrast levels and spatial frequency to determine which tests most readily reveal binocular summation in normal subjects. Tests included the low contrast Early Treatment Diabetic Retinopathy Study (ETDRS) and Pelli Robson contrast sensitivity charts plus high contrast ETDRS chart at 2.5 and 1.25% levels. One hundred and twenty-nine subjects were tested: 61% female, 39% male. A significant difference in binocular summation was found in different age groups for 2.5% and 1.25% Sloan low contrast acuity charts and the Pelli Robson chart, but not for high contrast ETDRS visual acuity. Generally scores increased over the first three decades of life and reduced from the fifth decade. Linear regression showed significant associations between increased intraocular differences and reduced binocular summation and increased age and reduced binocular summation. Low contrast acuity charts may be useful clinical measures of binocular summation.

Reference

Normative reference ranges for binocular summation as a function of age for low contrast letter charts.
Pineles SL, Velez FG, Yu F, et al.
STRABISMUS
2014;22:167-75.

STRABISMUS

BT for intermittent exotropia
Reviewed by: Fiona Rowe
Vol 22 No 2
 

This study aimed to evaluate the effect of botulinum toxin (BT) on the amount of deviation and fusional control state of intermittent exotropia. Twenty-one patients (five male and 16 female) aged five to 18 years with progression of exotropia were recruited. Each had reduced fusional control and an increased Newcastle control score (≥3). BT of 10 units Dysport was given to the lateral rectus muscles. A minimum follow-up of six months was allowed. The Newcastle control score increased significantly over follow-up. Stereoacuity improved from 224.6 ±278.9” pre-treatment to 100 ±100.3” post treatment. The near angle of deviation reduced from 26.4 ±10.1 to 1.8 ±10.3PD and the distance angle of deviation reduced from 30.9 ±7.1 to 11.8 ±14.4PD. Binocular alignment within 10PD was achieved by 38.1% at distance fixation. Mild ptosis was documented in nine patients (42.8%). The authors propose this to be a promising treatment.

Reference

Efficacy of botulinum toxin in the treatment of intermittent exotropia.
Etezad Razavi M, Sharifi M, Armanfar F.
STRABISMUS
2014;22:176-81.

STRABISMUS

Dyslexic reading improved by vergence training
Reviewed by: Fiona Rowe
Vol 22 No 2
 

The aim of this study was to evaluate if reading performance could be improved by a period of compensatory vergence training in dyslexic children with otherwise normal binocular vision. The study included 13 children with dyslexia – mean age of 13.08 ±0.49 years at time of treatment. Twelve control dyslexics were also recruited with a mean age of 13.08 ±0.51 years. Over a five week period training was provided averaging 11.75 times ±2.53SD. The mean number of words read pre-treatment was 87.83 ±16.80 and after treatment was 95.58 ±18.08 which was significant, p=0.0066. The mean number of words read by control subjects at baseline was 85 ±19.68 and at the second visit, 89.37 ±19.71 which showed no significant difference. An increase in positive fusional reserves at near fixation was recorded for the treatment group. The authors conclude there is a beneficial improvement in reading ability following vergence training for dyslexics.

Reference

Can vergence training improve reading in dyslexics?
Ramsay MW, Davidson C, Ljungblad M, et al.
STRABISMUS
2014;22:147-51.

STRABISMUS

Iran prevalence of amblyopia
Reviewed by: Fiona Rowe
Vol 22 No 2
 

The authors aimed to determine the prevalence of amblyopia, its relation with refractive errors and its determinants. The target population was all children aged seven years in Iran. There were 3675 of 4157 children who participated (88.4%) with final analysis on 3547 children with full data. Sixty-three had amblyopia (1.88%: 1.91% male and 1.85% female). Of that 60.3% had unilateral amblyopia; 73.9% had corrected visual acuity better than 20/40 and 5.7% with visual acuity <20.80; 51.3% had strabismic amblyopia, 27% anisometropic, 9.5% isotropic, 11.1% strabismic plus anisometropic, and 1% with stimulus deprivation amblyopia due to cataract. Amblyopic eyes were more hyperopic with a higher mean cylinder error. The authors conclude that attention should be paid to hyperopia and astigmatic refractive errors and to treatment of strabismus cases.

Reference

The prevalence of amblyopia in 7-year-old school children in Iran.
Hashemi H, Yekta A, Jafarzadehpur E, et al.
STRABISMUS
2014;22:152-7.

STRABISMUS

Medial rectus recession in Grave’s orbitopathy
Reviewed by: Fiona Rowe
 

The purpose of this retrospective study was to analyse the surgical effect / success rate of recession of the medial rectus in 90 patients with horizontal diplopia. Mean age was 52.5 ±9.4 years. Of that 24% had unilateral medial rectus recession and 76% had bilateral recessions. Mean recession was 3.3 (2-5mm) for unilateral recession and 4.5 (2.7-7mm) for bilateral. Preoperative angle of deviation was not influenced by muscle volume or decompression approach. Dose response was 1.0 (-0.6 to 3.8) degrees/mm for unilateral recession and 1.4 (0.2 to 3) degrees/mm for bilateral. Overall approximately 80% required one operation only to resolve horizontal diplopia.

Reference

Unilateral and bilateral medial rectus recession in Grave’s orbitopathy patients.
Jellema HM, Saeed P, Braaksma-Besselink Y, et al.
STRABISMUS
2014;22:182-7.

AMERICAN JOURNAL OF OPHTHALMOLOGY

Does paediatric uveitis reactivate after treatment with anti-TNF-a drugs?
Reviewed by: Efrosini Papagiannuli
Vol 22 No 1
 

As a potentially blinding disease that can affect 7-27/100000 children, uveitis remains a rare condition, where little evidence based data is available to guide management decisions. Most paediatric uveitis cases are chronic, anterior and non-infectious and may be associated with juvenile idiopathic arthritis (JIA) or remain undifferentiated. Anti-TNF-a treatment is the treatment of choice in patients with uveitis resistant to standard therapy with steroids and traditional immunomodulators (commonly Methotrexate). The aim is a flare free period (quiescence) of 18-24 months, before considering to discontinue any systemic treatment. The aim of this paper was to address the risk of reactivation whilst patients were still on anti-TNF-a (primary outcome), after they stopped it (secondary outcome) and also potential risk factors for reactivation. This retrospective cohort study builds upon a previously published paper by the same authors, demonstrating that 75% of children with non-infectious uveitis achieved quiescence within 12 months with anti-TNF-a (Infliximab or Adalimumab) and that JIA uveitis was most likely to respond to treatment. (J Rheumatol 2013;40:1394-1403). It included patients whose management started between 01/2000 and 07/2012 and casenotes were reviewed, documenting whether there was non-infectious non-traumatic uveitis and whether they had received anti-TNF-a treatment. Quiescence was defined as having ‘slightly active’ (<0.5 cells) or inactive uveitis whilst on <2 drops/day of topical steroids and no oral steroids, sustained for >2 visits over a 28 day period. Infliximab and Adalimumab were the only anti-TNF-a drugs used and any concomitant treatment with steroids, Methotrexate and Mycophenolate Mofetil was documented. Among 50 children who achieved quiescence whilst on anti-TNF-a, 39 were considered at risk for reactivation whilst on anti-TNF-a (primary outcome) and 19 after discontinuation of treatment (secondary outcome). Of that 60% were female, nearly half had JIA and most were treated with Infliximab. The overall proportion relapsing within one year was 27.8% [95% CI]. The risk was higher in children who had discontinued Infliximab at 63.8% versus 21.6% in children still on treatment. In the group that discontinued anti-TNF-a, the risk of reactivation was higher if treated with Adalimumab, rather than Infliximab (HR 13.4, p=0.01). Reactivation was also higher in children that were older at the time of diagnosis of uveitis (HR 1.3, p=0.09). The duration of disease suppression on treatment (quiescence for >1.5 years) had no significant effect on the risk of reactivation. The authors conclude that whilst most children on anti-TNF-a remain quiescent, the majority will reactivate once off treatment. It also seemed that Infliximab was more often followed by remission, but that there was no benefit of prolonged drug induced disease suppression on the reactivation risk. The authors are aware of their study limitations, such as its retrospective nature, the variability in follow-ups and the fact that largely non-uveitis specialists were assessing disease activity. They also point out that some quiescent children may have been lost to follow-up and that there are limitations to the study’s generalisability as the cohort largely consisted of female Caucasians. They recommend further studies to assess whether short versus longer periods of suppression maintenance increase the risk of reactivation after drug cessation, to evaluate the potential advantages of Infliximab versus Adalimumab and to identify possible biomarkers that predict the likelihood of remission after treatment is discontinued.

Reference

Uveitis reactivation in children treated with tumor necrosis factor-a inhibitors.
Leman MA, Lewen MD, Kempen JH, Mills MD.
AMERICAN JOURNAL OF OPHTHALMOLOGY
Epub ahead of print.

AMERICAN JOURNAL OF OPHTHALMOLOGY

Endophthalmitis after intravitreal injections in France
Reviewed by: Efrosini Papagiannuli
Vol 22 No 1
 

In this nationwide, retrospective, multicentre case series, the authors looked at the incidence and characteristics of endophthalmitis after intravitreal injections of anti-VEGFs and steroids, given for a variety of posterior segment conditions (macular oedema secondary to diabetes or retinal vein occlusion, neovascular macular degeneration, degenerative myopia and miscellaneous cases). They wished to describe the clinical and bacteriological features, management and outcome (visual acuity) of these eyes. A total of 316,576 intravitreal injections from 25 centres were identified that underwent injections from January 2008 to June 2013. The intravitreal drugs used consisted of ranibizumab, bevacizumab, triamcinolone acetonide and dexamethasone implant. Case note review detected 65 cases of presumed endophthalmitis (0.021% incidence), with a median time to presentation of four days post-injection. Presumed endophthalmitis was defined as any acute intraocular inflammation presenting within four weeks of intravitreal injection and requiring intravitreal antibiotics (vancomycin with ceftazidime). The commonest symptom was loss of vision and an offending germ was detected in nearly 45%. The most frequent pathogen was coagulase negative Staphylococcus (78.3%).There was a significant association (p=0.001) with an increased incidence of endophthalmitis if a disposable conjunctival mould assist device or prophylaxis with antibiotic / antiseptic were used. Sixty-five percent of patients post episode had worse visual acuity at three months follow-up and one patient developed phthisis. In 61.7% of patients intravitreal injections were restarted after resolution of the endophthalmitis at a median time of 113 days. The authors conclude that the incidence of endophthalmitis after intravitreals is low, but associated with a poor visual prognosis. The strength of this study lies in its large sample size, but they acknowledge the various limitations, primarily its retrospective nature, the possibility of missing data or underreported endophthalmitis cases, the heterogenicity of the management in different French centres (relating to the use of corticosteroids and initial vitrectomy) and the fact that systemic antibiotics were part of the management, which is current practice in France but not supported in the literature. Furthermore they point out that because of variability in the level of asepsis and antisepsis from country to country (use of drapes, face masks, surgical hat, sterile gloves and gowns), any generalisability of their results to other countries ought to be very careful. They recommend further studies to define specific guidelines for endophthalmitis management.

Reference

Endophthalmitis after intravitreal injections: incidence, management and visual outcome.
Dossarps D, Bron AM, Koehrer P, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
Epub ahead of print.

BRITISH JOURNAL OF OPHTHALMOLOGY

Efficacy and safety of intravitreal aflibercept injection in wet age-related macular degeneration
Reviewed by: Jonathan Chan
Vol 22 No 1
 

This is a sub-group study of double masked review of patients randomised to different dosages and treatment frequency compared between aflibercept and ranibizumab treatment. This is to evaluate the efficacy and safety of intravitreal aflibercept (IVT-AFL) in Japanese patients with wet age-related macular degeneration (AMD) from the VIEW 2 trial. Patients were randomised to: 0.5mg IVT-AFL every four weeks; 2mg IVT-AFL every four weeks; 2mg IVT-AFL every four weeks after three monthly injections; or 0.5mg ranibizumab every four weeks. The main efficacy outcomes included vision maintenance and best corrected visual acuity (BCVA) at week 52. The VIEW 2 trial was a prospective, double-masked, multinational, active-controlled, randomised, clinical trial. Eligible patients had sub-foveal choroidal neovascularisation (CNV) or juxta foveal CNV with subfoveal leakage demonstrated on fluorescein angiogram (FA) with appropriate lesion characteristics. Since polypoidal choroidal vasculopathy (PCV) is considered to be part of the AMD spectrum, patients with PCV lesions were not excluded. All Japanese patients in the IVT-AFL groups (n=70) at week 52 maintained vision, compared with 96% of Japanese patients (n=23/24) treated with ranibizumab. Japanese patients in all treatment groups show improvement in BCVA after treatment. Those treated at four weekly intervals with ranibizumab, compared with aflibercept treated at four weekly intervals and also eight weekly intervals, experienced similar gains in BCVA from baseline. The 0.5mg group had higher gains due to an unexpected drop in BCVA between screening and baseline. The central retinal thickness and mean area of choroidal neovascularisation decreased in all treatment groups with similar magnitude. The ocular treatment – adverse events were similar across the treatment groups. The authors concluded that IVT-AFL was effective and well tolerated in Japanese patients. The outcomes of this sub-group population were consistent with those in the overall VIEW 2 trial study of other population subjects.

Reference

Efficacy and safety of intravitreal aflibercept injection in wet age-related macular degeneration: outcomes in the Japanese subgroup of the VIEW 2 study.
Ogura Y, Terasaki H, Gomi F, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2015;99:92-7.

BRITISH JOURNAL OF OPHTHALMOLOGY

Silicone band loop myopexy in the treatment of myopic strabismus fixus
Reviewed by: Jonathan Chan
Vol 22 No 1
 

This is a retrospective case series of chart review of patients who had silicone band loop myopexy between January 2008 to December 2012 for myopic strabismus fixus (MSF) at a tertiary eye centre in India. A minimum period of two months follow-up after surgery was required for inclusion, and patients who had previous incomplete details or preoperative alignment were excluded. The main outcome measures include alignment postoperatively, improvement in extraocular motility postoperatively, and intraoperative and posterior complications. The surgical procedure was performed under general anaesthetic and intraoperative forced duction test was performed in order to assess the tightness of each of the rectus muscles. A fornix base conjunctival incision was placed in the superotemporal quadrant approximately 10 to 12mm from the limbus. The lateral rectus and the superior rectus muscles were hooked and isolated and both were examined intraoperatively. A scleral tunnel of 3 to 4mm in length was constructed 14 to 16mm from the limbus in between the bellies of the superior rectus and lateral rectus using a hockey J stick buckle blade. A type 240 silicone band was then passed under the lateral rectus and through the scleral tunnel and the superior rectus. The two ends were then passed through a Watzke sleeve and tightened to bring the bellies of the superior rectus and lateral rectus together by pulling the two ends in opposite direction. The conjunctiva was closed with interrupted sutures using an 8-0 non-absorbable monofilament nylon suture. Forced duction test was repeated to look for the tightness and a medial rectus recession was performed if the medial rectus tightness was found to be significant. A total of 26 eyes of 15 patients had surgery at the mean age of 27.8±16.4 years (range 7-72 years). A mean follow-up was 7.9±8.4 months (range 2-28 months, and median of four months). Eleven patients had bilateral loop myopexy where four patients underwent unilateral loop myopexy. Sixteen eyes underwent additional medial rectus recession between a range of 5-7.5 mm. At the last follow-up, the mean abduction limitation improved to -1.5±1.3 from -2.9±1.2, P=0.0; mean elevation limitation improved to -1.2±0.9 from -2.8±1.1, P=0.0; mean esotropia improved to 16.9±17.4 PD from 79.3±32.3PD, P=0.0; success was defined as deviation less than 20 PD, was achieved in 73%. Mean hypotropia at presentation was 8.9±10.1 PD, which improved to 0.6±1.3 PD, P=0.007. Foreign body sensation was reported by two patients (three eyes) and a silicone band removal was performed in two eyes of one patient five months postoperatively. The patient maintained alignment 24 months postoperatively. The authors concluded that a modified fixated silicone band loop myopexy with or without medial rectus recession is a safe and effective procedure in the management of MSF and improves alignment significantly. Further studies particularly those comparing suture silicone band loop myopexy looking at the anterior ciliary circulation and muscle related complications are required.

Reference

Silicone band loop myopexy in the treatment of myopic strabismus fixus: surgical outcome of a novel modification.
Shenoy BH, Sachdeva V, Kekunnaya R.
BRITISH JOURNAL OF OPHTHALMOLOGY
2015;99:36-40.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Management of diffuse OSSN with topical chemotherapy
Reviewed by: Anjali Gupta
Vol 22 No 1
 

Ocular surface squamous neoplasia (OSSN) can be localised to the conjunctiva or, less commonly, diffusely spread over the conjunctiva and cornea. Localised OSSN can be treated by surgical removal with adjuvant cryotherapy and chemotherapy with low rates of recurrence. Diffuse OSSN is more difficult to treat without morbidity due to necessary reconstruction of the ocular surface after excision. Primary topical chemotherapy provides an alternative that avoids the potential complications of wide excision. This retrospective case series studied eyes with diffuse OSSN that were treated with topical 5FU 1% or topical MMC 0.04% as a primary therapy. Diffuse OSSN was defined as a lesion extending over five or more limbal clock hours or having extensive central or paracentral corneal spread. Thirty-two eyes were managed as treatment naive diffuse OSSN. Twenty-nine cases received MMC 0.04%, including one case that was partially surgically debulked prior to therapy. Seven out of the 28 cases (25%) displayed recurrence or persistence of OSSN. 5FU 1% was used in three cases of treatment naive OSSN and recurrence or persistence of disease was observed in all cases. Thirteen cases had previously undergone a single unsuccessful treatment course for diffuse OSSN, administration of a second treatment course was successful in six (46%) of these patients. A strategy of switching treatment protocol from 5FU 1% to MMC 0.04% following treatment failure was attempted in seven patients, and tumour clearance was achieved in four. Conversely, retreatment with 5FU 1% following treatment failure with MMC 0.04% was attempted in five cases, and tumour clearance was successful in four. In four patients, following treatment with MMC 0.04% or 5FU 1%, tumour clearance was ultimately achieved with excision and cryotherapy of a localised area of recurrence. No serious long-term complications were noted with MMC 0.04%, one case treated with 5FU 1% experienced a focal stromal melt. The authors conclude that diffuse OSSN often requires multiple treatment efforts when compared with localised disease. Switching chemotherapeutic regimens following a treatment failure may be useful.

Reference

Management of diffuse ocular surface squamous neoplasia: efficacy and complications of topical chemotherapy.
Rudkin AK, Dempster L, Muecke JS.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2015;43:20-5.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Micropulse vs. continuous wave trans scleral diode cyclophotocoagulation in refractory glaucoma
Reviewed by: Anjali Gupta
Vol 22 No 1
 

Continuous wave cyclophotocoagulation (CWCPC) delivers continuous high intensity energy to the ciliary body in an attempt to reduce aqueous secretion and hence lower IOP. It is often used as a treatment of last resort due to the potential side-effects of hypotony, visual deterioration and phthisis bulbi. Micro pulse cyclophotocoagulation (MPCPC) administers a series of repetitive, short pulses of laser energy separated by rest periods. A preliminary study has described MPCPC to achieve IOP reduction that is sustained over 12-18 months without significant ocular comorbidity. This randomised comparative exploratory study compared the efficacy and safety of MPCPC and CWCPC in refractory glaucoma. Forty-eight patients with refractory glaucoma (IOP>21 unresponsive to maximal tolerated medical therapy with or without previous surgical intervention) and a best corrected visual acuity (BCVA) of 6/60 or worse were randomised to either CWCPC or MPCPC. Twenty-four patients were allocated to each group. The primary outcome of success was IOP between six and 21mmHg and at least 30% reduction in IOP with or without medical therapy. After 12 months, 75% of patients in the MPCPC vs. 29% in the CWCPC achieved the primary outcome. However, there was no significant difference between the two treatment modalities achieving primary outcome success at 18 months. More complications were seen in the CWCPC group, including prolonged anterior chamber (AC) inflammation and phthisis bulbi. The authors conclude that MPCPC provides a more consistent and predictable effect in lowering IOP with minimal complications.

Reference

Micropulse versus continuous wave trans scleral diode cyclophotocoagulation in refractory glaucoma: a randomised exploratory study.
Aquino MCD, Barton K, Tan AMWT, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2015;43:40-6.

CORNEA

Oral omega-3 fatty acid treatment for dry eye in contact lens wearers
Reviewed by: Sharmina Khan
Vol 22 No 1
 

This study evaluates the effect of dietary omega-3 fatty acid supplementation of dry eye symptoms, tear film tests, and conjunctival impression cytology in patients with contact lens wear-associated dry eye. In this randomised double-blind, multi-centred trial, contact lens wearers (n= 496) were randomised to receive either omega-3 fatty acids or placebo capsules (corn oil) twice daily for six months. At each visit a questionnaire of dry eye symptoms were completed, tear film break up time (TBUT), Schirmer’s test, conjunctival impression cytology. Outcomes measures were improvement in symptoms and lens wear comfort. Changes in TBUT, Schirmer’s test and Nelson grade (conjunctival impression cytology scores) at six months were secondary outcomes. Exclusion criteria were: current ocular infection, history of laser refractive surgery, allergic conjunctivitis, herpetic eye disease, diabetes, liver disease, pregnancy, lactation, HIV, hepatitis, those on systemic tetracyclines, systemic corticosteroids, topical medications other than artificial tears. Computer use was not allowed for the duration of the study. The mean contact lens wear time was 3.1 +/- (0.91) years in the omega-3 fatty acid supplements group and 3.3 +/- 2 (1.6) years. Noncompliance and gastric irritation resulted in 14 patients dropping out of the trial. The mean age was comparable in both groups. Patients were instructed not to use artificial tears two hours before testing. The mean improvement in symptom score was significantly improved from baseline for the cohort receiving omega-3 supplements versus the placebo group, this was associated with a significant increase in TBUT. However, improvement in Schirmer’s test was small. Omega-3 is an essential fatty acid that can’t be synthesised by the body but has to be ingested. It has anti-inflammatory properties. Omega-6 fatty acids are pro-inflammatory. The ratio of omega-3 and omega-6 determines the overall inflammatory status of the body.

Reference

Oral omega-3 Fatty acid treatment for dry eye in contact lens wearers.
Bhargava R, Kumar P.
CORNEA
2015;34:413-20.

CORNEA

Tear film thickness after treatment with artificial tears in patients with moderate dry eye disease
Reviewed by: Sharmina Khan
Vol 22 No 1
 

In recent years artificial tear drops addressing tear film osmolarity have come onto the market. Increased tear evaporation and reduced tear volume results in tear hyperosmolarity. This triggers an inflammatory process leading to apoptosis of goblet and epithelial cells. Trehalose, a naturally occurring disaccharide has been marketed. This study uses anterior segment ultra-high resolution optical coherence tomography (OCT) to assess pre corneal tear film thickness (TFT) following use of artificial tear drops; (i) Thelaoz Duo – Trehalose 30mg/ml, sodium hyaluronate 1.5mg/ml, sodium chloride, trometamol, hydrochloric acid (ii) Hyabak, unpreserved sodium hyaluronate 0.15% and (ii) Hydrabak – unpreserved sodium chloride 0.9%, sodium dihydrogen phosphate dehydrate, disodium hydrogen phosphate dodecahydrate; in patients with dry eye disease. The study found significant differences between artificial tears in increasing TFT after administration. Product (i) containing Trehalose & sodium hyaluronate increased TFT to 240 minutes compared to product (ii) containing sodium hyaluronate which had a TFT of 40 mins. Hyaluronic acid has been reported to have longer TFT times in previous studies using different measurement techniques. The Trehalose containing product had a significantly longer TFT time thought to be related to Trehalose interaction with lipid membranes and requires further investigation. There was no reported difference in patient satisfaction between the three drops.

Reference

Tear film thickness after treatment with artificial tears in patients with moderate dry eye disease.
Schmidl D, Schmetterer L, Witkowska KJ, et al.
CORNEA
2015;34:421-6.

CURRENT EYE RESEARCH

Nicotine accelerates diabetes induced retinal changes
Reviewed by: Khadijah Basheer
Vol 22 No 1
 

This study investigated the influence of nicotine in an experimentally induced diabetic rat model. They used non-invasive high-resolution spectral domain optical coherence tomography (SD-OCT) imaging to provide quantitative information on the temporal alterations of retinal structures at the micrometer resolution level. Cigarette smoking has been associated with progression of diabetic retinopathy and nicotine alone has been shown to promote pathological effects on the retinal pigment epithelium, photoreceptors and cells in the outer nuclear layer in mice. Chronic nicotine toxicity has also been proven to increase the severity of induced choroidal neovascularisation, diabetic nephropathy and cataract development in rat models. The nicotine treatment group in this study demonstrated an average decrease in total retinal thickness of 9.4μm where the loss was mainly in the outer nuclear layer. In the combined nicotine and diabetes group they measured an increase in total retinal thickness, thought to represent a synergistic relationship between hyperglycaemia and nicotine leading to increased fluid retention within the retina, appearing as diabetic macular oedema. One explanation could be that smoking causes a reduction in blood flow due to vasoconstrictive effects of nicotine and hypoxia due to diabetes may perturb auto-regulation leading to oedema. These findings may be important in encouraging patients who smoke or use products containing nicotine to cease to prevent amongst other health risks, the worsening of diabetic retinopathy.

Reference

Nicotine accelerates diabetes-induced retinal changes.
Boretsky A, Gupta P, Tirgna N, et al.
CURRENT EYE RESEARCH
2015;40(4):368-77.

CURRENT EYE RESEARCH

Optic nerve head perfusion response to reduced blood pressure and increased intraocular pressure
Reviewed by: Khadijah Basheer
Vol 22 No 1
 

The purpose of this prospective study was to test the hypothesis that blood flow autoregulation in the optic nerve head has less reserve to maintain normal blood flow where there is a blood pressure induced decrease in ocular perfusion pressure compared to an intraocular pressure induced decrease. They measured the optic nerve head blood flow in two groups of anaesthetised primates, one group had their blood pressure reduced by administration of pentobarbital, the second group had their intraocular pressure increased via an anterior chamber reservoir. Their results showed that optic nerve head blood flow was significantly different between the two groups, showing a greater decline in the blood pressure group. This vulnerability of the optic nerve head to low blood pressure adds to the evidence related to the haemodynamic pathophysiology in glaucoma and ophthalmologists should take this into account in the clinical setting.

Reference

Optic nerve head blood flow response to reduced ocular perfusion pressure by alteration of either the blood pressure or intraocular pressure.
Wang L, Cull GA, Fortune B.
CURRENT EYE RESEARCH
2015;40(4):359-67.

JOURNAL OF CATARACT AND REFRACTIVE NEWS

Closed-chamber haptic re-externalisation for posteriorly displaced sclerotomy and inadequate haptic tuck in glued posterior chamber intraocular lenses
Reviewed by: Sharmina Khan
Vol 22 No 1
 

This technique (online video http://jcrsjournal.org) emphasises the importance of both symmetrical and sufficient anterior placement of sclerotomies to externalise an adequate length of the haptics, which in turn provides good centration and stability of the intra-ocular lens (IOL). The authors describe a secondary procedure to address sclerotomies that haven’t been placed too posteriorly or asymmetric and resulted in IOL tilt. A new sclerotomy is created anterior to the first, avoiding engaging the iris root by turning off the anterior chamber maintainer (AMC) to prevent posterior bowing of the iris. A sharp needle is pointed down through the sclera and into the posterior chamber and then horizontally immediately behind the iris plane in the vitreous cavity. Through a side-port and using micro forceps the haptic is internalised into the eye. The ACM is turned off and a second micro forceps is passed through the anteriorly placed sclerotomy, the haptic grasped and brought out through the anteriorly placed sclerotomy, then tucked into an intra-scleral tunnel. A 26-gauge needle is used to create the intra-scleral tunnel. The advantage of this technique is that it avoids IOL explantation and increases the overall haptic length available for tucking.

Reference

Closed-chamber haptic reexternalization for posteriorly displaced sclerotomy and inadequate haptic tuck in glued posterior chamber intraocular lenses.
Jacob S, Agarwal A, Agarwal A, Narasimhan S.
JOURNAL OF CATARACT AND REFRACTIVE NEWS
2015;41:268-71.

JOURNAL OF CATARACT AND REFRACTIVE NEWS

Toric intraocular lens rotation related to the capsulorrhexis
Reviewed by: Sharmina Khan
Vol 22 No 1
 

The risk factors for postoperative rotation in the early post-operative period; a longer axial length, younger patients, and with the rule astigmatism as described by Miyake T et al. (JCRS 2014) in a case series of six eyes. This letter adds that a capsulorrhexis, larger than the size of the optic is an additional risk factor for post-operative rotation. The authors of the letter identify that in four out of six of Miyake’s cases the capsulorrhexis was larger than the size of the optic. Miyake responds that a large capsulorrhexis is a risk factor for late postoperative rotation. The ideal capsulorrhexis is 0.5mm smaller than the optic diameter. The anterior and posterior capsule fuse with the intraocular lens (IOL) minimising postoperative rotation. Fibronectin plays a major role in IOL-capsular bag adhesion.

Reference

Toric intraocular lens rotation related to the capsulorrhexis.
Leonardo Torquetti.
JOURNAL OF CATARACT AND REFRACTIVE NEWS
2015;41(2):483.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Amniotic membrane efficacy
Reviewed by: Fiona Rowe
Vol 22 No 1
 

This prospective randomised study evaluated the effect of amniotic membrane (AM) in reducing inflammation, fibrosis, adhesion formation and ocular movement restrictions following strabismus surgery. This study used 22 rabbits: all with superior rectus recession in both eyes with AM placed in the right eye only. Dynamometer tests were undertaken at 15 days post-surgery in 17 rabbits after which the rabbits were killed and orbits exenterated. The same was undertaken for five rabbits but at 30 days post-surgery. At 15 days post-surgery, inflammation levels of eyes with AM were statistically greater than eyes without AM and fibrosis levels were lower for eyes with AM. At 30 days post-surgery, inflammation levels were statistically greater and fibrosis levels lower. At 15 days, dynamometer tests showed that greater force was needed to displace eyes without AM. This was not significant at 30 days. Further study is required to confirm the increased inflammatory response due to use of human AM in rabbits.

Reference

Amniotic membrane for reducing the formation of adhesions in strabismus surgery: experimental study in rabbits.
Kirsch D, Lowen MS, Cronemberger MF, Sato EH.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(6):341-7.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Atropine penalisation for amblyopia in the UK
Reviewed by: Fiona Rowe
Vol 22 No 1
 

The authors aimed to determine the current clinical practice of atropine penalisation (AP) in the UK, to identify perceived barriers limiting use of AP as a first line treatment and ascertain whether any of the barriers could be resolved. An anonymised online survey was distributed through the UK professional society for orthoptists (BIOS). Responses were obtained from 151 orthoptists (13% return). Seventy-one percent indicated they had department protocols regarding the use of AP. Twenty-five percent used AP as the first line of treatment for amblyopia. Children younger than seven years were most commonly targeted. Its use was considered in more moderate to severe density of amblyopia. Eighty-nine percent would stop treatment if no improvement in visual acuity was noted over three consecutive visits. Forty-eight percent favoured daily atropine, 41% alternate day, 29% weekend use and 9% weekly use. Reported recognised side-effects included skin rash / flushing, mood changes, eye irritation / pain. Barriers to use included department-specific problems with use of AP, inability to prescribe and inability to obtain atropine. The survey showed that the percentage of orthoptists offering AP as a first line treatment has increased. It was avoided in older children because of perceived risks of intractable diplopia. Orthoptists still raise concerns regarding general efficacy, side-effects and reverse amblyopia.

Reference

Use of atropine penalisation to treat amblyopia in UK orthoptic practice.
Piano M, Newsham D, O’Connor AR.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(6):363-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Collamer lenses for accommodative ET
Reviewed by: Fiona Rowe
Vol 22 No 1
 

Posterior chamber phakic IOL implantation was used to treat patients with accommodative esotropia (ET) with the goal of eliminating hyperopia and producing orthophoria. Three patients (six eyes) aged 18-22 years had an average follow-up of 17 months ±6.24. The mean preoperative spherical equivalent cycloplegic refraction was 6.04D ±0.53 and postoperative refraction of 0.41D ±0.21. This was stable over the follow-up period. All three achieved orthophoria or microesophoria postoperatively. Postoperative corneal oedema occurred in one case which recovered rapidly. One patient complained of postoperative glare which reduced over time. Preliminary results show that IOL implantation for accommodative esotropia is safe, effective, predictable and stable with low incidence of postoperative complications and positive patient satisfaction. Further large scale studies are recommended.

Reference

Treatment of adults with accommodative esotropia using implantable collamer lenses.
Shi M, Jiang H, Ye Y, Chen B.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2015;52:31-6.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Cyanoacrylate vs. fibrin glue
Reviewed by: Fiona Rowe
Vol 22 No 1
 

This study compared the safety and efficacy of fibrin and cyanoacrylate glue for refixating the recessed muscle to the sclera in patients undergoing strabismus surgery. The fibrin group (a) included 21 eyes of 15 patients; mean age of 11.6 ±7.49 years. The cyanoacrylate group (b) included 19 eyes of 15 patients; mean age of 12.4 ±9.98 years. Both groups were comparable for age. Each group consisted of eight males and seven females. The average time per muscle attachment was 1.48 ±0.69 minutes (group a) and 2.42 ±0.58 minutes (group b). Postoperative alignment within 10PD was achieved in every patient at six weeks. One patient developed consecutive exotropia at three months. There was no significant difference in pain between groups. Group b had significantly more chemosis with conjunctival reaction and total inflammation score. Two patients in group b developed localised granuloma formation over the site of muscle reattachment and required surgical removal of this. Both glues were equally efficacious for muscle reattachment but there were clear issues with cyanoacrylate. The authors recommend fibrin glue as a safe, effective and bio tolerant alternative to sutures and cyanoacrylate glue for recessions in strabismus surgery.

Reference

Comparative evaluation of cyanoacrylate and fibrin glue for muscle recession in strabismus surgery.
Topiwala P, Bansal RK.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(6):349-54.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

IO surgery
Reviewed by: Fiona Rowe
Vol 22 No 1
 

The purpose of this paper was to evaluate the efficacy of a new surgical technique in reducing inferior oblique muscle overaction (IOOA) consisting of suturing the muscle to the sclera at the Gobin point with tendon sparing and using a micro incision to minimise related tissue trauma. Eight patients aged 5-51 years were included. At four months postoperative the mean angle reduced to 8PD exotropia in five patients with a V-exotropia. One patient with unilateral IOOA had reduced from 18 to 3PD vertical deviation. Two patients with infantile esotropia had complete resolution of elevation in adduction with no vertical imbalance. All had improvement in lateral incomitance. The authors propose the technique as simple, safe, reversible and modular in terms of suturing. They propose additional benefits of little risk to developing vorticose haemorrhage or macular damage, no errors in IO muscle hooking and no risk of anti-elevation syndrome.

Reference

New surgical intervention for the weakening of the inferior oblique muscle: equatorial scleral anchor.
Tomarchio S, Sabetti L, Tomarchio M, Berarducci A.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2015;52:58-60.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Management of congenital NLD obstruction
Reviewed by: Fiona Rowe
Vol 22 No 1
 

The authors evaluated changes in management of congenital nasolacrimal duct obstruction (CNLDO) by surveying 1495 Association for Paediatric Ophthalmology & Strabismus (AAPOS) members. The survey consisted of 21 multiple choice questions with anonymised return. Responses were received from 127 members and six were excluded as potentially biased. A total of 84% were completed by North American members and 16% by international members which was reflective of the AAPOS organisational membership. Ninety-five percent regularly treat CNLDO. For treatment in the first year of life 45% perform the Crigler manoeuvre on the initial visit for infants younger than six months. Of these 82% instruct carers to massage the duct and 17% offer office probing but this is significantly more for those with >10 years’ experience. Surgical treatment includes 79% recommending surgery from 13 months of age for unresolved cases, and 12% for infants aged 10-12 months. Seventy-nine percent chose probing as their primary treatment. In children with first surgery at age two years, 53% chose non-probing procedures. For children aged three years at first procedure, 67% chose non-probing procedures. For failed probing, most opted for silicone intubation with or without balloon dacryoplasty. With silicone intubation, 64% preferred monocanalicular tubes typically left in place for three to four months. For bicanalicular tubes, most were removed in the office and the remainder in the operating room. With regard to risk of amblyopia, 91% regularly check refraction at the initial visit and 45% recheck when aged one to two years. This study found a striking lack of consensus among ophthalmologists.

Reference

Congenital nasolacrimal duct obstruction: common management policies among pediatric ophthalmologists.
Dotan G, Nelson LB.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2015;52:14-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Postop improved fusion and stereopsis in IDEX
Reviewed by: Fiona Rowe
Vol 22 No 1
 

This study aimed to evaluate changes in binocular visual function in patients with different ages before and after surgery to explore the optimal timing of intermittent exotropia surgery. The study comprised 28 females and 25 males. Fifty-three patients were split into three groups of <7 years, 7-13 years and >13 years. Median age was 6.07, 10.82 and 16.298 years respectively. They were examined preoperatively and at two and six weeks postoperatively. A total of 32% had a family history of strabismus and 38% had their strabismus detected during routine physical examination. The angle of deviation at near and distance significantly increases with older age with median angles of 55, 45 and 85PD respectively for the three groups at near fixation and 37.5, 40 and 80PD at distance fixation. Near stereoacuity improved significantly as did distance stereoacuity. Peripheral and central fusion improved postoperatively and improvement was noted across all age groups. The authors propose that surgery for intermittent exotropia can be postponed appropriate to the case.

Reference

Improvement in fusion and stereopsis following surgery for intermittent exotropia.
Feng X, Zhang X, Jia Y.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2015;52:52-7.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Refocus on children programme results
Reviewed by: Fiona Rowe
Vol 22 No 1
 

The authors describe the logistics and results of the refocus on children programme for the 2012-13 school year. The aim of the programme was to help school nurses provide access to comprehensive vision care and reduce unnecessary visual loss or impairment. The programme was designed to reach children in 23 low income schools. The Plusoptix screener was used and 2750 children were successfully screened. Of that 741 were referred (27%). Consent for further examination was obtained for 419 children and 192 were given glasses. There was a 49% response rate to the request for feedback from teachers for these children. Children receiving glasses typically wore them regularly. A total of 70% of teachers reported that children liked their glasses. Positive comments from teachers included reduced squinting, better vision, improved academic performance, and improved child focus on lessons, improved participation and interaction. Negative comments included children being embarrassed to wear glasses, taking poor care of glasses and glasses being used as a toy. Overall the study examined 56% of children referred. As the process was completed at school, the students received the support of the entire team which helped with wearing new glasses. Half of the children referred needed glasses.

Reference

Combining automated vision screening with on-site examinations in 23 schools: ReFocus on Children Program 2012 to 2013.
Peterseim MM, Papa CE, Parades C, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2015;52:20-4.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Treatment of infantile cataract with secondary IOLs
Reviewed by: Fiona Rowe
Vol 22 No 1
 

The authors examined whether secondary IOL insertion is helpful in the successful treatment of monocular infantile cataracts. Eleven children were reviewed: eight with cataract extraction at one to four months of age and three at five to seven months of age. Secondary posterior chamber IOL insertion was undertaken at one to six years. Surgery for the one to four month infants resulted in obtaining visual acuities of ≥20/150 in 87.5%. One child developed stereopsis. Surgery for the five to seven month infants showed that poor visual acuity prior to IOL implantation remained poor. Contact lens and patching compliance markedly affected final visual acuity. The quality of aphakic correction and patching combined had the best effect. The authors conclude that cataract extraction with proper patching and use of aphakic contact lenses prior to four months of age with compliance for at least one year results in better outcomes / insertion of secondary IOLs will maintain vision.

Reference

The role and efficacy of secondary intraocular lenses in the treatment of monocular infantile cataracts.
Kruger TL, Monson BS, Baker JD.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(6):370-4.

NEURO-OPHTHALMOLOGY

Literature review of isolated ocular motor nerve palsies
Reviewed by: Claire Howard
Vol 22 No 1
 

Patients aged over 50 presenting with isolated nerve palsies of the third (pupil sparring), fourth or sixth nerves, are often described as having microvascular extraocular palsies. This review looks critically at the evidence surrounding these microvascular non-arteritic extraocular palsies and suggests practical ideas on diagnosis and management of suspected cases. The condition itself and its management provoke divergent opinions. The review covers a wide range of features including incidence, pathology, causes, clinical presentation, and yield of imaging, progression, recovery as well as management options. The literature review demonstrates that the clinical presentation is more diverse than often thought. According to the authors, the two crucial differential diagnoses that must be considered immediately in an isolated ocular motor palsy are giant cell arteritis and posterior communicating artery aneurysm. Overall the authors suggest a pragmatic approach to diagnosis, investigation and management from initial presentation.

Reference

Microvascular non-arteritic ocular motor nerve palsies – what we know and how should we treat?
Galtrey CM, Schon F, Nitkunan A.
NEURO-OPHTHALMOLOGY
2015;39(1):1-11.

NEURO-OPHTHALMOLOGY

Long-term retinal changes following unilateral retrobulbar optic neuritis
Reviewed by: Claire Howard
Vol 22 No 1
 

The aim of this study was to assess the longitudinal changes in retinal nerve fibre layer (RNFL) thickness after a first attack of optic neuritis and to investigate the impact of treatment on RNFL thinning at one year after the attack. RNFL thickness of the attack and normal fellow eyes was measured by optical coherence tomography on presentation and three, six and 12 months post attack in treatment and non-treatment groups. The treatment group consisted of subjects that opted for systemic steroids to hasten recovery time, patients were not randomised into the groups. Findings showed that the baseline RNFL thickness was similar in the attack and fellow eyes. Progressive RNFL thinning was seen in the attack eye over the 12 month period. Importantly, the RNFL thickness was similar between the treatment and non-treatment groups. This has clinical significance for the treatment offered to patients following unilateral retrobulbar optic neuritis. In this study, initial treatment with systemic steroids did not alter the degree of RNFL loss at 12 months, suggesting that the treatment was ineffective. Before treatment using steroids is discarded, however, a large sample size randomised control trial is required to investigate the effectiveness of treatment in full.

Reference

Longitudinal changes in retinal nerve fibre layer thickness after an isolated unilateral retrobulbar optic neuritis: 1 year results.
Yau GSK, Lee JWY, Lau PPK, et al.
NEURO-OPHTHALMOLOGY
2015;39(1):22-5.

NEURO-OPHTHALMOLOGY

Structural effects of migraine on the retina
Reviewed by: Claire Howard
Vol 22 No 1
 

Migraine is a common, chronic, multifactorial neuro-vascular disorder typically characterised by recurrent attacks of disabling headache and autonomic nervous system dysfunction (migraine without aura). Up to one third of patients also have neurological aura symptoms (migraine with aura). The objective of this study was to evaluate the retinal nerve fibre layer (RNFL) thickness in migraine patients with or without aura and to search for possible structural effects of migraine on the retina. Parameters related to RNFL thickness of right and left eyes’ average superior, inferior, nasal and temporal quadrant values were found to be similar in migraine and control subjects. When focusing on the RNFL thickness of right and left eyes and the migraine parameters, there were no significant differences between migraine sufferers with and without aura. The overall conclusion from the study was that migraine disease with or without aura does not have any effect on the thickness of the RNFL.

Reference

Retinal nerve fibre layer thickness in migraine patients with or without aura.
Bahceci Simsek I, Aygun D, Yildiz S.
NEURO-OPHTHALMOLOGY
2015;39(1):17-21.

OPHTHALMIC EPIDEMIOLOGY

Are retinal vein occlusions seasonal? And if so why might that be?
Reviewed by: Jonathan C P Roos,
Vol 22 No 1
 

Some studies have reported a strong seasonal pattern to central retinal vein occlusion (CRVO) occurrence with a peak in January, but other studies have failed to replicate this finding. The authors sought to determine data for Stockholm’s seasonal variation in CRVOs and retrospectively reviewed the charts of all patients presenting to the main Stockholm eye hospital – St Eriks – between 2008 and 2013. There were 854 such cases in the study period with an incidence of 2/10,000 in the over 40, and 7/10,000 in the over 85 year group. Attendance records showed a peak in the late winter / early spring period which was significantly higher than the late summer / early autumn (p<0.0002). Could it be that Swedes are too busy sailing in the archipelago to bother about sight loss in the summer? Or do the cold winters freeze their eyes? The authors suggest a number of possible explanations to account for this finding. Cold temperatures have been shown to be able to result in increased blood viscosity and clotting factors, and blood pressure too has been reported to increase during the winter months. However, the most compelling reason given is that Vitamin D levels slowly run out during the winter months and the timing of the lowest level of Vitamin D coincides with the highest rate of CRVO. Could this just be a coincidence? Though causality cannot be proven, a recent meta-analysis has shown that low Vitamin D levels are associated with high blood pressure and endothelial dysfunction including changes to clotting factors. The authors cite a study in which patients at increased risk of CRVO (type II diabetics) were given Vitamin D supplements and this improved their blood pressure and endothelial cell responsiveness to changes in flow. At the moment this all remains speculative, but fascinating.

Reference

Seasonality and incidence of central retinal vein occlusion in Sweden: a 6-year study.
Epstein D, Kvanta A, Lindqvist PG.
OPHTHALMIC EPIDEMIOLOGY
2015;22(2):94-7.

OPHTHALMIC EPIDEMIOLOGY

Is an increased homocysteine level associated with greater risk of AMD?
Reviewed by: Jonathan C P Roos
Vol 22 No 1
 

Basic research studies have implicated homocysteine in causing vascular endothelial dysfunction and inflammation, and this has been borne out in large observational studies which suggested that elevated homocysteine is associated with increased risk of cardiovascular disease. In order to determine whether there might be an association also between age-related macular degeneration (AMD) and homocysteine, Christen et al. prospectively studied a cohort of healthy female health professionals over the age of 40 from the Womens Health study. This was a large study involving 27,479 persons followed up over 10 years. Four hundred and fifty-two developed AMD, of which 182 were visually significant. The study authors did not find statistically significant evidence to suggest that elevated homocysteine levels were associated with an increased risk of developing AMD, nor was there a correlation for the subset with visually significant AMD (worse than 20/30). This large prospective study suggests that homocysteine levels do not contribute greatly to the risk of developing AMD.

Reference

Prospective study of plasma homocysteine level and risk of age-related macular degeneration in women.
Christen WG, Cook NR, Ridker PM, Buring JE.
OPHTHALMIC EPIDEMIOLOGY
2015;22(2):85-93.

OPHTHALMIC EPIDEMIOLOGY

Which factors predispose to pingecula development in a rural Chinese population?
Reviewed by: Jonathan C P Roos
Vol 22 No 1
 

The authors report a cross-sectional study which aimed to determine the prevalence and risk factors for developing pingecula in a rural Chinese population near Shanghai. Nine hundred and fifty-nine persons were recruited from a single village and asked to complete a questionnaire detailing their medical and social history and were then examined by slit-lamp to determine whether pingecula were present. The prevalence was high with 75% of patients being found to have pingecula. Next the authors performed regression analysis to determine whether sex, educational attainment, smoking, alcohol consumption, tear break-up time, age or sunlight exposure might be associated with an increased risk of pingecula formation. Only the last two were found to be statistically associated (age p<0.002) and sunlight (more than two hours per day p<0.001).

Reference

Prevalence and associated factors of pinguecula in a rural population in Shanghai, Eastern China.
Le Q, Xiang J, Cui X, et al.
OPHTHALMIC EPIDEMIOLOGY
2015;22(2):130-8.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

The dynamic nature of orbital cavernous haemangiomas
Reviewed by: James Hsuan
Vol 22 No 1
 

This paper seeks to address the question of how much do orbital cavernous haemangiomas actually change over time, and if there are any identifiable factors which can predict which lesions will grow and which will remain stable. In particular, if a haemangioma was found incidentally are there any factors which can predict the likelihood of it requiring surgery in the future? The clinical records and images were reviewed of 104 patients with cavernous haemangiomas, 31 of these had been incidental findings. In all, 79 patients required surgical intervention. This included 11 from the incidentally diagnosed group who unsurprisingly had less proptosis and were smaller at diagnosis than the symptomatic group. For all haemangiomas, factors predictive of needing surgery were greater size, choroidal folds, being male and extraconal location, but no factors were found which could predict which of the incidental lesions were more likely to grow. Overall the incidentally found lesions were less likely to require surgery, and most were either stable or grew at less than 1mm a year. Despite this, 35% of these did require surgery within five to six years of diagnosis. Symptoms which led to surgery included reduced acuity, diplopia and increasing proptosis. The authors advise regular observation and imaging initially, but if incidental lesions are stable for five years they are very likely to remain stable in the long-term. This is an extensive multicentre review with useful data regarding the management of asymptomatic, incidentally found cavernous haemangiomas, and will help when advising patients on the likelihood of needing surgery in the future.

Reference

The natural history of orbital cavernous hemangiomas.
McNab AA, Tan JS, Xie J, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:89-93.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Wide variation in the volume of the sphenoid trigone
Reviewed by: James Hsuan
Vol 22 No 1
 

This is a radiological study of the volume of the sphenoid trigone in normal subjects. The authors were interested to see how much volume could be gained by removal of the trigone during an orbital decompression for thyroid eye disease. Specifically, they were looking at the natural anatomical variation and differences due to gender or race. CT scans from 120 normal subjects were found with 40 each from three racial groups; Asian, black/African American and white. Each group had 20 males and females, all aged 30-60. Both orbits of each subject were analysed to measure the volume of the trigone by measuring the area of the trigone in every 2mm axial slice between the superior and inferior orbital fissures. These areas were then summed and multiplied by two (the slice thickness) to give the volume. The mean volume overall was 1.53 cm³ with a range of 0.2 to 4.4 cm³. Male subjects had a significantly larger mean volume than females but there was no significant difference between races. Interestingly, right trigones were significantly smaller than left. An important finding emphasised by the authors is the very wide natural range in volumes, with some subjects having 10 times the volume of others within the same sub-group. Furthermore there can even be large differences between the two orbits in the same subject, with the trigone on one side having twice the volume of the other. Understanding this extreme variability is important in planning decompression surgery and the paper makes this point clearly with good supporting data.

Reference

CT-based measurements of the sphenoid trigone in different sex and race.
Lefebvre DR, Yoon MK.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:155-8.

OPHTHALMIC RESEARCH

Influence of overall intraocular lens diameter on rotational stability
Reviewed by: Bheemanagouda Pati
Vol 22 No 1
 

It has been shown that approximately one in three patients undergoing cataract surgery have >1.0D corneal astigmatism and managing this during surgery is important to achieve good refractive outcomes. One of the widely used ways of reducing preoperative astigmatism during cataract surgery is by using toric intraocular lenses (IOL). It is ideal if this lens has minimal or no postoperative rotation. The aim of this study was to determine the influence of the overall IOL diameter on rotational stability. The IOLs used in this study were ACR6 (12mm) and IDEA 613 XC (13mm) (both CromaPharm GmbH., Austria). Both these IOLs are monofocal, hydrophilic acrylic single-piece with water content of 26%. For the study, all IOLs had markings on them to determine rotational stability postoperatively, but were spherical in design. Sixty eyes of 60 patients were included in the study. Eighteen patients were lost to follow-up at the three month visit. Absolute rotation in the small and large diameter IOL groups was 4.4º (SD: 4.0; range: 0.3-17.8) and 3.0º (SD: 2.4; range: 0.1-7.8) respectively. The differences between the two IOLs were not found to be statistically significant. Thus the authors concluded that the effect of the overall length of an IOL appears to have little impact on early rotation after cataract surgery.

Reference

Influence of the overall intraocular lens diameter on rotational stability.
Harrer A, Hirnschall N, Maedel S, Findl O.
OPHTHALMIC RESEARCH
2015;53(3):117-21.

OPHTHALMOLOGICA

RaScaL Study
Reviewed by: Sofia Rokerya
Vol 22 No 1
 

The RaScaL study was a six month, single-centre, controlled, prospective phase I/II study in which subjects with diabetic macular oedema (DME) and associated peripheral nonperfusion on ultrawide-field fluorescein angiography (UWFA) were randomised to: (1) study arm: ranibizumab (0.5 mg) injection plus UWFA-guided peripheral scatter laser, or (2) control arm: triamcinolone acetonide (4.0 mg) injection plus macular laser (focal / grid).The study population consisted of 22 patients (30 eyes, eight bilateral patients) ≥18 years of age with type 1 or 2 diabetes mellitus glycosylated hemoglobin (HbA 1c ) ≤12%, and visual impairment due to DME. The key inclusion criteria were: (1) stability of diabetes within three months; (2) visual impairment due to DME in at least one eye that was eligible for macular laser treatment in the opinion of the investigator, and (3) peripheral nonperfusion on UWFA of at least three clock hours. Mean initial Early Treatment Diabetic Retinopathy Study and best corrected visual acuity (ETDRS BCVA) was 54 letters (20/80) in the control and 59 letters (20/60) in the RaScaL group. Mean central foveal thickness (CFT) on optical coherence tomography (OCT) was 473 in the control group and 493 in the RaScaL group. Both the RaScaL and the control (combination intravitreal triamcinolone acetonide 4.0mg plus macular laser) groups achieved visual acuity improvements at six months, of 13 and 10 letters, respectively. None of the RaScal patients suffered a loss of visual acuity at six months. There was also improvement in the CFT on OCT in both groups with a trend for less thickening in the RaScaL group (279 vs. 367μm). The RaScaL group trended to a more gradual but consistent improvement in visual acuity and CFT; conversely, the control group of triamcinolone plus macular laser demonstrated a trend toward earlier improvement in initial visual acuity and OCT but later recurrence of DME. The RaScaL group required rescue treatment for recurrent DME in only 33% of patients at six months as compared to 80% in the control group. This difference was clinically and statistically significant (p<0.003). This finding supports the hypothesis that this subgroup of DME may have an underlying pathobiology significantly driven by peripheral retinal ischaemia, resulting in VEGF production, and ultimately leading to increased permeability of the retinal vasculature in the macula. As a result, treatment with this approach of peripheral scatter laser and VEGF inhibition may result in better durability, decreased burden of injections, and long-term control in this subset of patients with DME. Decision by imaging signatures is an attractive concept that requires further trials. This study was limited by its small size, slight imbalance in baseline visual acuity between groups and limited follow-up and imaging technology. Although Optos P200MA provides excellent, reliable, reproducible images through small pupils, however, the view of the anterior periphery and the superior and inferior views may be limited by the lids or lashes. Through six months of follow-up, this small pilot study suggests that the RaScaL treatment strategy consisting of ranibizumab plus UWFA-guided peripheral scatter laser may be a reasonable therapeutic approach in treating patients with DME associated with peripheral retinal nonperfusion.

Reference

RaScaL: single intervention with ranibizumab plus peripheral laser for diabetic macular edema associated with peripheral nonperfusion on ultrawide-field fluorescein angiography.
Suñer I, Peden M, Hammer M, et al.
OPHTHALMOLOGICA
2015;233:89–95.

RETINA

ILM peeling in primary rhegmatogenous retinal detachment
Reviewed by: Saruban Pasu
Vol 22 No 1
 

This author retrospectively analysed the correlation between internal limiting membrane (ILM) peeling and the occurrence of a postoperative epiretinal membrane (ERM) in patients who underwent vitrectomy for rhegmatogenous retinal detachment (RD). There were 135 medical records investigated. Seventy patients underwent ILM peeling, 65 did not. Patients found to have an ERM at the time of surgery were excluded. At 12 month follow-up, no ERM was identified in the ILM peel group, whereas ERM was observed in 14 of 65 patients in the non ILM peel group. Removing the ILM can remove the ERM precursor cells from the retinal surface. ERM occurred in 12 of the 14 patients (85.7%) within three months of the RD surgery. The authors found no significant correlation between ERM development and age, best corrected visual acuity (BCVA) at initial diagnosis, macular involvement, break location, number, shape, RD extent, or gas type in non-ILM peeling patients. Although ILM peeling has been shown to prevent ERM formation post RD repair, the authors conclude that a longer term prospective study with a greater number of patients is needed to provide evidence that ILM peeling in all patients is beneficial.

Reference

Effect of internal limiting membrane peeling on the development of epiretinal membrane after pars plana vitrectomy for primary rhegmatogenous retinal detachment.
Nam KI, Kim JY.
RETINA
2015;35:880-5.

RETINA

OCT positioning regimen in macular hole surgery
Reviewed by: Saruban Pasu
Vol 22 No 1
 

The authors set out to evaluate an OCT-based positioning regimen for macular hole surgery. Patients were advised to maintain prone positioning until the hole was confirmed to be closed based on daily OCTs. Surgery consisted of 23-gauge phacovitrectomy with internal limiting membrane (ILM) peel and 20% SF6. A retrospective case note review was carried out on 33 patients (35 eyes) who had undergone this regimen. Mean baseline visual acuity was 20/220 with a mean hole size of 465 microns. Seventeen percent were diagnosed with myopic degeneration, while 37% were found to have chronic holes (more than or equal to 12 months duration). Day one OCT images were obtained in 89%, day two in 97% and day three in 100% of eyes. The authors suggest to obtain clear OCT images in gas filled eyes, the focus on the OCT machine should be set between -10D and -20D. Closed holes began to reopen by the first postoperative week. Eighty-nine percent were closed on day seven, 83% closed on day eight to 14, 80% were closed one month after surgery. Three percent did not close postoperatively, 9% reopened at two weeks, 3% reopened at four weeks and 3% at six weeks. Risk factors for failure to maintain closure were identified as large holes, chronic holes and myopic degeneration. The authors suggest if the patient has no risk factors, positioning can be stopped once the hole has closed. If the patient has one risk factor, advice to position can be extended for a few days after hole closure. If the patient has two or three risk factors, seven days of prone positioning even if the hole is closed on day one is recommended using this OCT based positioning regimen.

Reference

Optical coherence tomography – based positioning regimen for macular hole surgery.
Chow DR, Chaudhary KM.
RETINA
2015;35:899-907.

RETINA

OCT positioning regimen in macular hole surgery
Reviewed by: Saruban Pasu
Vol 22 No 1
 

The authors set out to evaluate an OCT-based positioning regimen for macular hole surgery. Patients were advised to maintain prone positioning until the hole was confirmed to be closed based on daily OCTs. Surgery consisted of 23-gauge phacovitrectomy with internal limiting membrane (ILM) peel and 20% SF6. A retrospective case note review was carried out on 33 patients (35 eyes) who had undergone this regimen. Mean baseline visual acuity was 20/220 with a mean hole size of 465 microns. Seventeen percent were diagnosed with myopic degeneration, while 37% were found to have chronic holes (more than or equal to 12 months duration). Day one OCT images were obtained in 89%, day two in 97% and day three in 100% of eyes. The authors suggest to obtain clear OCT images in gas filled eyes, the focus on the OCT machine should be set between -10D and -20D. Closed holes began to reopen by the first postoperative week. Eighty-nine percent were closed on day seven, 83% closed on day eight to 14, 80% were closed one month after surgery. Three percent did not close postoperatively, 9% reopened at two weeks, 3% reopened at four weeks and 3% at six weeks. Risk factors for failure to maintain closure were identified as large holes, chronic holes and myopic degeneration. The authors suggest if the patient has no risk factors, positioning can be stopped once the hole has closed. If the patient has one risk factor, advice to position can be extended for a few days after hole closure. If the patient has two or three risk factors, seven days of prone positioning even if the hole is closed on day one is recommended using this OCT based positioning regimen.

Reference

Optical coherence tomography – based positioning regimen for macular hole surgery.
Chow DR, Chaudhary KM.
RETINA
2015;35:899-907.

RETINA

OCT positioning regimen in macular hole surgery
Reviewed by: Saruban Pasu
Vol 22 No 1
 

The authors set out to evaluate an OCT-based positioning regimen for macular hole surgery. Patients were advised to maintain prone positioning until the hole was confirmed to be closed based on daily OCTs. Surgery consisted of 23-gauge phacovitrectomy with internal limiting membrane (ILM) peel and 20% SF6. A retrospective case note review was carried out on 33 patients (35 eyes) who had undergone this regimen. Mean baseline visual acuity was 20/220 with a mean hole size of 465 microns. Seventeen percent were diagnosed with myopic degeneration, while 37% were found to have chronic holes (more than or equal to 12 months duration). Day one OCT images were obtained in 89%, day two in 97% and day three in 100% of eyes. The authors suggest to obtain clear OCT images in gas filled eyes, the focus on the OCT machine should be set between -10D and -20D. Closed holes began to reopen by the first postoperative week. Eighty-nine percent were closed on day seven, 83% closed on day eight to 14, 80% were closed one month after surgery. Three percent did not close postoperatively, 9% reopened at two weeks, 3% reopened at four weeks and 3% at six weeks. Risk factors for failure to maintain closure were identified as large holes, chronic holes and myopic degeneration. The authors suggest if the patient has no risk factors, positioning can be stopped once the hole has closed. If the patient has one risk factor, advice to position can be extended for a few days after hole closure. If the patient has two or three risk factors, seven days of prone positioning even if the hole is closed on day one is recommended using this OCT based positioning regimen.

Reference

Optical coherence tomography – based positioning regimen for macular hole surgery.
Chow DR, Chaudhary KM.
RETINA
2015;35:899-907.

SEMINARS IN OPHTHALMOLOGY

Effect of anti-VEGF treatment on PED morphology
Reviewed by: Jayavani Myneni,
Vol 22 No 1
 

This retrospective study of 30 eyes assessed the effect of anti-VEGF on morphology of pigment epithelial detachments (PED) secondary to age-related macular degeneration (AMD). Thirty eyes of 28 patients with PED were compared to 30 eyes of 30 patients with AMD without PED component. The subjects in both groups were individually matched for gender, BCVA before treatment with anti-VEGF, follow-up period and age. All patients received ranibizumab monthly for the first three months followed by PRN treatment. Mean follow-up period was 19.8 months. Morphological changes of PED on OCT were qualitatively assessed by three masked investigators. OCT scans of the same orientation were chosen for comparison only if there was agreement among the three investigators. These changes were correlated with improvements in BCVA. Number of injections and BCVA were compared among the two groups. Extent of PED when compared to baseline were graded as unchanged in 36.7%, reduced in 40% and significantly reduced in 23.3% of eyes. No eyes showed an increase in size. No evidence was found that improvements in PED correlate to improvements in BCVA. No RPE tear was observed in this study. The limitations of the study are small size of study groups, retrospective comparison, lack of quantitative analysis of PED volume and grouping of all types of PED without classification. This study provides supporting evidence that anti-VEGF therapy stabilises or improves PED extent in wet AMD.

Reference

The effect of intravitreal anti-VEGF on the pigment epithelial detachment in eyes with the exudative type of age-related macular degeneration.
Kalouda P, Anastasakis A, Tsika C, Tsilimbaris KM.
SEMINARS IN OPHTHALMOLOGY
2015;30(1):6-10.

THE NEW ENGLAND JOURNAL OF MEDICINE

How much money is wasted on tests prior to cataract surgery? And why?
Reviewed by: Jonathan C P Roos
Vol 22 No 1
 

For routine cataract surgery, numerous studies have found that preoperative testing does not contribute usefully to safety or surgical success. Despite such guidelines, tests ordered for patients prior to phacoemulsification in the US remains high. To quantify the associated costs, Chen and colleagues studied patients on Medicare – the US federal health insurance system which pays for 80% of cataract surgery in the United States. The authors studied a cohort of patients who had such surgery in 2011, comparing the tests performed in the month prior to surgery with those ordered for the same patient in the preceding 11 months. Patients were identified using billing codes used by Medicare which allowed identification of the practice setting, geographical area and surgeon. There were 500,000 such patients selected randomly. The following tests were considered when ordered a month before surgery: full blood count (FBC), urea & electrolytes (U&Es), Coag screen, urinalysis, ECG, cardiac echo, stress test, chest x-ray and pulmonary function tests. Fifty-three percent of patients had at least one such preoperative test and the excess spend in the month prior to surgery (compared to the 11 month baseline) totalled $17.2million. The main predictive factor for ordering such tests was unrelated to the patient or region: 8% of cataract surgeons ordered preoperative tests on all their patients; 36% ordered preoperative tests for more than 75% of patients. Thirteen percent of patients had one of the tests listed above, 11% had two, 10% three, 7% four and 13% had five or more – and all for routine cataract surgery! Surprisingly the rate had not changed after the introduction of clinical guidelines aimed at curtailing such testing. The authors concluded that preoperative testing represents a significant expense; publishing guidelines does not necessarily alter surgeon behaviour and physicians vary greatly in their practice. Is this relevant to UK ophthalmologists? This study reminds us to be careful guardians of the health budget, to be aware of guidelines’ effects on budgets and illustrates how colleagues abroad approach practice – particularly when transatlantic treaties currently being negotiated at the EU level could possibly put UK practitioners in direct competition with other such providers.

Reference

Preoperative medical testing in medicare patients undergoing cataract surgery.
Chen C, Lin G, Bardach NS, et al.
THE NEW ENGLAND JOURNAL OF MEDICINE
2015;372:1530-8.

AMERICAN JOURNAL OF OPHTHALMOLOGY

Is there an association between dry eye disease and depression and anxiety?
Reviewed by: Efrosini Papagiannuli
Vol 21 No 6
 

Dry eye disease is a widespread ocular surface condition (prevalence 5.5-33.7%) that has been previously linked to systemic diseases, such as Sjogren, rheumatoid arthritis and more recently possibly also depression, in small population-based studies. The authors’ aim was to investigate this association in a large, adult, inclusive study and for this reason conducted a retrospective, case-control review of all patients over 18 years, that were seen in the outpatient setting of a large university hospital between 2008 and 2013. They used diagnostic codes (ICD-9) for dry eyes, depression, anxiety and rheumatoid arthritis (as a validating disease), and utilised these codes to calculate odds ratios separately for dry eyes and each of the other diseases. They applied logistic regression models to estimate associated odds ratios, which was each adjusted for age and sex, along with 95% confidence intervals. A total of 460,611 patients were included, with 7207 patients with dry eyes, 20,004 with anxiety and 30,100 with depression. Seventy-six patients were excluded because age could not be determined. The odds ratios between dry eyes and anxiety were 2.8 (95% CI 2.6, 3.0), and between dry eyes and depression 2.9 (95% CI 2.7, 3.1). The odds ratios between rheumatoid arthritis and dry eyes was 3.2 (95% CI 2.8, 3.7). The authors also found a greater association of dry eyes and rheumatoid arthritis in the younger age group. These findings are statistically significant and confirm the association between dry eyes and anxiety / depression in (so far) the largest population cohort. This may have implications for the healthcare providers to be aware and perhaps initiate screening for these comorbidities in dry eye patients. The authors argue that the major strength of their study is its large and diverse size, which makes the results more generalisable. They also point out the limitations imposed by its retrospective nature, which did not allow any conclusions about causality, and the possibility of confounding factors, such as possible medications that patients were using to treat depression (tricyclic antidepressants being a risk factor for dry eyes due to their anticholinergic effect). The authors recommend further studies assessing the above, as well as the effects of treated depression on the management of dry eyes.

Reference

The association between dry eye disease and depression and anxiety in a large population – based study.
Van der Vaart R, Weaver MA, Lefebvre C, Davis RM.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2015;159(3):470-4.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Effect of topical diclofenac on postoperative PRK pain: RCT
Reviewed by: Anjali Gupta
Vol 21 No 6
 

A major disadvantage of excimer laser photorefractive keratectomy (PRK) is pain and discomfort after the surgery, which is thought to be due to damage to corneal sensory nerve fibres or local release of inflammatory substances. Pain only resolves once corneal re-epithelialisation is complete. Previous studies have shown that topical nonsteroidal anti-inflammatory drugs (NSAIDS) can cause corneal complications when used excessively and for long time periods. The aim of this prospective RCT was to determine the role of topical diclofenac in the management of post PRK pain. Sixty-eight adults undergoing bilateral PRK for myopia with or without astigmatism were included. All patients were given 100mg of extended release oral diclofenac at 9pm the evening before surgery and at 9am on the day of surgery. The case group (n=38) were given diclofenac 0.1% drop, one drop 2h preoperatively and one drop four times a day postoperatively for three days. The control group (n=30) were given artificial tears. All patients were examined two days after the procedure. Results showed no significant difference between the reported pain (measured on a scale graded between 0-10) experienced between the case and control groups. Other subjective symptoms, including photophobia and functional activity, were also not different between the two groups. Eyelid oedema and conjunctival injection levels were significantly higher in the control group. The authors conclude that the administration of topical diclofenac in addition to oral diclofenac to treat post PRK pain is unnecessary.

Reference

Effect of topical diclofenac on postoperative photorefractive keratectomy pain: a randomized, controlled trial.
Eslampoor A, Ehsaei A, Abrishami M.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:810-4.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Risk factors for NTG in a young Korean population
Reviewed by: Anjali Gupta
Vol 21 No 6
 

Previously known ocular and systemic risk factors for normal tension glaucoma (NTG) include myopia, peripapillary atrophy, disc haemorrhage, migraine, obstructive sleep apnoea, thyroid disease and cerebral infarction. However, most NTG risk factor studies have examined patients aged 40 years and older. The aim of this retrospective, population based, case control study was to assess risk factors for NTG in a young population. Among participants from the Korea National Health and Nutrition Examination Survey 2009-2010, 80 subjects with NTG aged 19-39 years and 4015 controls were included in the study. Variables assessed included diabetes mellitus, hypertension, cholesterol levels, migraine, family history of glaucoma, BMI, cold extremity, fasting plasma glucose, haemoglobin level and refractive error. Results showed that fasting capillary glucose ≥200mmol/L, high myopia (SE≺-6D) and low HDL cholesterol were associated with NTG in a young Korean population.

Reference

Risk factors for open-angle glaucoma with normal baseline intraocular pressure in a young population: the Korea National Health and Nutrition Examination Survey.
Kim MJ, Kim MJ, Kim HS, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:825-32.

JAMA OPHTHALMOLOGY

Effect of selenium and vitamin E supplements on the development and progression of cataracts
Reviewed by: Lona Jawaheer
Vol 21 No 6
 

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) investigated the influence of dietary supplements on the development of prostate cancer in a group of 35,533 middle aged and older, apparently healthy men. The SELECT Eye Endpoint (SEE) study is an ancillary study involving a subset of 11,267 of the SELECT participants that looked specifically into the impact of selenium (200μg per day from L-selenomethionine) and vitamin E supplements (400IU per day of all rac-α-tocopheryl acetate) on the development of cataract in those patients. Participants with a pre-existing diagnosis of cataract were excluded from analysis in the SEE study. Group participants were randomised into one of four treatment arms: selenium only, vitamin E only, combination of selenium and vitamin E, placebo. The participants were followed up at six monthly intervals and were asked to report new diagnoses of cataract or cataract extraction. Over a mean period of 5.2 years (SD 1.6 years), 185 patients developed cataracts in the selenium group compared to 204 in the no-selenium group (HR, 0.91; 95% CI, 0.75-1.11; p=.37), and 99 patients underwent cataract extraction in the selenium group compared to 120 in the no-selenium group (HR, 0.84; 95% CI, 0.64-1.09; p=.19). In the vitamin E group, 197 patients developed cataracts in the treatment group compared to 112 in the placebo group (HR, 1.02; 95% CI, 0.84-1.25; p=.81), and 114 patients underwent cataract extraction in the treatment group compared to 105 in the placebo group (HR, 1.08; 95% CI, 0.83-1.41; p=.58). The trial was terminated prematurely because of possible adverse effects of the supplements, including a 17% increase in the rate of prostate cancer in the vitamin E group. This is the first randomised control trial (RCT) that has looked at the impact of selenium in isolation on the development of cataract, and it does not provide evidence of any large beneficial effect (although a smaller but potentially important beneficial effect cannot not be ruled out). The lack of impact of vitamin E on cataract development seen in this trial echoes the findings of previous randomised trials.

Reference

Age-related cataract in men in the Selenium and Vitamin E Cancer Prevention Trial Eye Endpoints Study. A randomized clinical trial.
Christen WG, Glynn RJ, Gaziano, M et al.
JAMA OPHTHALMOLOGY
2015;133(1):17-24.

OPHTHALMIC RESEARCH

Results after 1.4mm biaxial cataract surgery and implantation of a new aspheric intraocular lens
Reviewed by: Bheemanagouda Patil
Vol 21 No 6
 

The aim of this study was to analyse the clinical outcome and higher-order aberrations (HOAs) after 1.4mm biaxial micro incision cataract surgery (B-MICS) and implantation of a new aspheric intraocular lens (IOL). A total of 157 eyes of 106 patients were enrolled in this study. The B-MICS (1.4mm, 26 eyes) was followed by an implantation of a micro incision aspheric Incise® IOL MJ14T (Bausch & Lomb, Rochester, NY, USA). The control groups consisted of patients operated with 1.8mm (coaxial MICS, Akreos MI60, 41 eyes), 2.2mm (small incision cataract surgery, Tecnis ZCB00, 44 eyes) and 2.2mm (small incision cataract surgery, CT Asphina, 46 eyes) coaxial phacoemulsification with implantation of an aspheric IOL. Intraoperative and postoperative complications, best-corrected visual acuity, HOAs for a 5.0mm pupil using the iTrace aberrometer and endothelial cell loss were evaluated. In the Incise group, the mean best-corrected visual acuity improved significantly from 0.4±0.27 logMAR preoperatively to 0.05±0.07 postoperatively. The root mean square of total ocular HOAs was measured at 0.419±0.191µm, spherical aberration was measured at 0.168±0.072µm and coma was measured at 0.213±0.200µm. The best-corrected visual acuity (p=0.097), total ocular HOA (p=0.630) and coma (p=0.193) showed no statistically significant difference between the four groups. The aspheric micro incision IOL was safely implanted through a 1.4mm incision and showed similarly good postoperative outcome in comparison to 1.8 and 2.2mm coaxial phacoemulsification.

Reference

Clinical results and higher-order aberrations after 1.4-mm biaxial cataract surgery and implantation of a new aspheric intraocular lens.
Von Sonnleithner C, Bergholz R, Gonnermann J, et al.
OPHTHALMIC RESEARCH
2015;53(1):8-14.

EYE

Ranibizumab for the treatment of age-related macular degeneration
Reviewed by: Nana Theodorou
Vol 21 No 6
 

This multicentre randomised prospective open label study compared 0.5 versus 2mg of ranibizumab in patients with submacular retinal pigment epithelial (RPE) detachment due to age-related macular degeneration. Four treatment regimens were used for the two strengths either monthly for 12 months or monthly for four months followed by repeat ranibizumab injections (RI) on a pro-re nata basis. Thirty patients participated with 36 eligible eyes. Outcome measures were best corrected standardised visual acuities, central 1mm thickness, subretinal fluid and cystoid macular oedema. Both groups showed reductions of the central 1mm thickness with vision improvement seen earlier for those receiving the higher dose. Cataract progression was similar in both groups but RPE tears developed most often in the 2.0mg dose. The authors conclude that although the visual and anatomical outcomes (weeks four and eight) were similar at the end of the study, the higher dose showed more rapid reductions and complete resolution of pigment epithelial detachment (PED).

Reference

Earlier therapeutic effects associated with high dose (2.0 mg) Ranibizumab for treatment of vascularized pigment epithelial detachments in age-related macular degeneration.
Chan C, Abraham P, Sarraf D, et al.
EYE
2015:29:80-7.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Adolescent optic disc haemorrhages
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The authors conducted this study to describe the clinical characteristics of multi-layered optic disc haemorrhages in adolescents. This was a retrospective review of 16 eyes (11 right and five left) of 16 patients with a mean age of 15 ±2.6 years. The main presenting symptoms were acute floaters or blurring. There were no precipitating causes or history. All were myopic. The average retinoscopy was -4.64 ±1.88D. Vitreous haemorrhages were noted in all eyes. Two eyes had subtle bleeding before the disc, five eyes with blood clots in the inferior prepapillary subhyaloid space and nine eyes with blood extending to the premacular area. Peripapillary subretinal haemorrhages and superficial flame haemorrhages were noted. Fifteen discs were crowded and tilted with small or absent cups. This was also the case for the fellow eyes. All haemorrhages resolved without aggressive treatment after one to three months. Multi-layered haemorrhages are relatively uncommon and most commonly affect myopic eyes with crowded and tiled discs. Visual outcome is usually excellent.

Reference

Multi-layered optic disc haemorrhages in adolescents.
Hwang JF, Liu C-J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(5):313-8.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Childhood canalicular lacerations
Reviewed by: Fiona Rowe
Vol 21 No 6
 

This retrospective study over 10 years provides data on canalicular lacerations in patients younger than 18 years of age. Of 137 lacerations, 38 (27.7%) met the inclusion criteria. 68.4% were white and 73.7% were male. The mean age was 10.8 years (1.1-17.9). Lacerations were due to dog bites (39.5%), other accidents such as fingers in eyes (21.1%), sports related (18.4%), falls (13.2%) and altercations (7.9%). Lacerations involved the lower lid in 65.8%. All due to dog bites were given IV antibiotics. Isolated lacerations occurred in 36.8%. It showed 13.1% had additional mild self-limiting injuries such as subconjunctival haemorrhage and 5.3% had concomitant orbital fractures. It showed 92.1% of repairs were undertaken in theatre under general anaesthetic and usually within one day of injury. The overall success rate, based on reported complete lack of epiphora, was 89.5%. 31.6% were bothered by eyelid appearance. The authors note that the cause of injuries in children differ to those in adults. These lacerations require monitoring and treatment.

Reference

Pediatric canalicular lacerations: epidemiology and variables affecting repair success.
Murchison AP, Bilyk JR.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:242-8.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Children’s clinic perceptions
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The authors designed a questionnaire intended to be child friendly and for use in a paediatric ophthalmology clinic. The aim of the study was to sample the opinions of the children attending their clinics. Topics in the questionnaire included timing and duration of visits, transport to hospital, what children liked and disliked at visits. They included multiple choice questions with free text space for additional comments. Verbal consent was obtained. Ninety-three children aged 2-16 completed the questionnaire (with and without parent assistance). Transport options included walking to hospital and travel by car, bus and train. Children indicated they saw an average 2.1 professionals per visit which was an under-report. The average duration of visit was 69 minutes (20-215). Sixty-seven percent felt there were sufficient toys and books available. Children reported the most difficult tests as visual acuity, retinoscopy, fundoscopy and binocular vision (in order). They reported the most fun tests as visual acuity, binocular vision, retinoscopy and fundoscopy (in order). Pain from eye drops was scored at an average of 4.2 (0 no pain, 10 most pain). Overall clinic experience was rated on average as 2.5 (0 poor, 10 best). The authors conclude there is room for improvement with explanation, sign-posting and education with regard to clinic visits.

Reference

A survey of children’s’ reported experience in out-patient pediatric ophthalmology clinics.
Tan NET, Lim WS, Jain S.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(5):270-3.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Masked bilateral SO palsy
Reviewed by: Fiona Rowe
Vol 21 No 6
 

This study examined the occurrence of masked bilateral superior oblique (SO) palsy with contralateral inferior oblique (IO) over action requiring further surgical intervention in children undergoing unilateral IO weakening surgery for presumed unilateral SO palsy. This retrospective study included 50 children with a mean age of 5.6 years. All had unilateral IO surgery. The mean follow-up period was 40 months. Nine (18%) developed masked bilateral SO palsy postoperatively causing reversal of initial hypertropia and requiring IO weakening of the unoperated eye. The preoperative primary hypertropia was significantly smaller for masked than unilateral SO palsy. A preoperative primary hypertropia of <5PD was associated with an odds ratio of 8.2 for requiring reoperation. This can be considered a risk for masked palsy.

Reference

Masked bilateral superior oblique palsy in children.
Dotan G, Roarty JD, Baker HD.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(6):333-6

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

OCT use with macular retinoblastoma
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The authors explore the use of portable hand-held spectral domain OCT (SD-OCT) in three eyes of three infants and young children with macular retinoblastoma. All were treated with chemotherapy and all had SD-OCT before and after treatment. The children were aged seven, nine and 33 months. In each case the tumour was exophytic with shallow subretinal fluid. No subretinal or vitreous seeding was noted. The foveaola was involved in one case. Mean tumour thickness by ultrasound was 4.8mm (four to six) and mean tumour base was 10.3mm (eight to twelve). Before treatment, the tumours showed smooth (two) or slightly irregular (one) surface topography and low to intermediate optical density by OCT. The normal anatomically intact retina appeared draped over the tumour in each case. After chemotherapy, tumour regression occurred in all cases. At one month, mean tumour thickness was 2.6mm (2.2-3) and tumour base was 6.8 (6-8). By OCT, tumour surface was smooth (one) and irregular (two). Subretinal fluid had almost resolved in all cases. At the tumour site, the retina showed full thickness disorganisation but with abrupt transition to normal retina in all cases. OCT was useful for anatomic monitoring of the macular area.

Reference

Hand-held spectral-domain optical coherence tomography of small macular retinoblastoma in infants before and after chemotherapy.
Cao C, Markovitz M, Ferenczy S, Shields CL.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:230-4.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Results of surgery in a case of FMNS
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The authors present the effects of the tenotomy and reattachment procedure on a patient with accommodative strabismus and fusion maldevelopment nystagmus syndrome (FMNS) who did not require strabismus correction. The ocular motility study of this patient allowed the opportunity to assess the isolated effects of pure 4-muscle T&R procedure on FMNS waveforms and to compare the resulting improvement to those predicted by both model simulation and INS-based analysis. Data and model predicted results concurred. T&R produced improvement in FMNS waveforms similar to those in INS across a broader field of gaze and reduced the Alexander’s law variation. Nystagmus acuity function (NAFX) plots after surgery versus gaze angle were higher and had lower slopes than preoperatively. Parents reported considerable improvement in functional abilities.

Reference

Fusion maldevelopment (latent/manifest latent) nystagmus syndrome: effects of 4-muscle tenotomy and reattachment.
Dell’Osso LF, Orge FH, Jacobs JB, Wang ZI.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:180-8.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Slanted MR surgery for convergence excess ET
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The authors aimed to evaluate the surgical outcomes of bilateral slanted recessions of the medial rectus (MR) muscles in patients with convergence excess esotropia (ET). This retrospective study included 16 patients with a mean age at surgery of 5.6 ±3.05 years. A minimum follow-up was four months. An angle of deviation less than 10PD was achieved in 14 children (88%) for distance and in nine (56%) for near fixation. Mean preoperative near-distance disparity of 20.3 ±6.5PD reduced to 4.37 ±5.6PD postoperatively. In two patients a distance disparity of 16PD persisted requiring treatment with bifocals. Bilateral slanted surgery involved recessing the lower muscle margins by 1-2mm more than the upper margins.

Reference

Slanted medial rectus recession is effective in the treatment of convergence excess esotropia.
Bayramler H, Unlu C, Dag Y.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(6):337-40.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Strabismus surgical outcome with unilateral visual loss
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The purpose of this study was to analyse the surgical outcome of strabismus surgery in patients with unilateral visual loss and horizontal strabismus. This was a retrospective review of 21 patients. Nine children were reviewed with a mean age of 10.2 ±1.7 years and 12 adults with a mean age of 41.9 ±4.8 years. Mean preoperative logMAR visual acuity in the deviating eye was 1.4 ±0.7. Mean follow-up was 20 months. The most common cause of visual loss was amblyopia followed by congenital cataract. Thirty-eight percent were esotropic and 62% exotropic. All underwent unilateral strabismus surgery with a successful outcome in 89% of children and 75% of adults.

Reference

Surgical outcome of strabismus surgery in patients with unilateral visual loss and horizontal strabismus.
Dotan G, Nelson LB, Mezad-Koursh D, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51(5):294-8.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Superior oblique muscle tuck
Reviewed by: Fiona Rowe
Vol 21 No 6
 

The authors investigate the efficacy and safety of isolated superior oblique tucking in patients with congenital superior oblique palsy. The study includes 21 cases: eight females and 13 males aged 2-34 years. All had obvious superior oblique under action and ipsilateral inferior oblique over action. The hyper deviation in primary position ranged from 6-18 prism dioptres: mean 10.9±3.3 preoperatively. Postoperatively, the mean deviation was 1.5 prism dioptres ±2.6 (2-6). In the reading position, the mean hyper deviation preoperatively was 15.6 prism dioptres ±3.6 (12-22) reducing postoperatively to 2.6 prism dioptres ±3.1 (0-10). The amount of superior oblique tuck ranged from 5-12mm, mean 8.3±2.3. There was no correlation between the surgical amount and corrected vertical deviation in the primary position and reading position, or with the preoperative deviation. The average corrected objective extorsion was 9.5 degrees ±3.3 in 14 patients and also not related to the amount of superior oblique tucking. The abnormal head posture resolved or was less than five degrees in all patients postoperatively. Three patients had a small reversal of their hyper deviation in primary position postoperatively. No patient complained of vertical diplopia in the reading position. All 21 patients had a -1 to -1.5 scale of limitation in elevation in adduction – iatrogenic Brown’s syndrome – but all asymptomatic. The authors proposed that isolated superior oblique tuck could correct hyper deviation of 10 prism dioptres on average and 15 prism dioptres maximum in reading position with correction of objective extorsion by approximately 9.5 degrees on average. For this surgery they recommend that patients have vertical deviations less than 15 prism dioptres in primary position, obvious superior oblique under action (Knapp type 2), ocular extorsion and superior oblique tendon laxity proven by forced duction test. The latter test was considered essential for planning surgery.

Reference

Superior oblique tucking for treatment of superior oblique palsy.
Li Y, Zhao K.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:249-54.

OCCULAR IMMUNOLOGY AND INFLAMMATION

Three years of experience with quantiferon-TB Gold Testing in patients with uveitis
Reviewed by: Nikolaos D Georgakarakos
Vol 21 No 6
 

Quantiferon-TB Gold is a new alternative to the tuberculin skin test that utilises synthetic peptides representing M. tuberculosis antigens ESAT-6, CFP-10, TB7.7 and upon incubation with whole blood IFN-γ is released from pre-sensitised T cells and can be measured by ELISA. This is a retrospective review and database search of the results of quantiferon – TB testing (QFT) on uveitis patients over a period of three years. This included all 343 patients tested for TB with QFT. For blood collection the authors used specialised blood collection tubes provided with the QFT intube test including a nil control tube an M. tuberculosis complex antigen tube and a mitogen tube the latter serving as a positive control. Of the 343 tested patients overall 80 (23.3 %) were positive and 253 (73.8%) negative (and non-conclusive for 10 patients). In 43 out of the 80 QFT+ patients the authors presumed a diagnosis of TB due to other clinical patterns such as radiologic findings, systemic diseases, exposure of a TB patient in the past or urinary tract TB. In the remaining 37 QFT+ patients another associated disease explaining their uveitis was detected (33 with sarcoidosis, one each with Behcet’s, toxoplasmosis, spondyloarthropathy, multifocal chorioretinitis and panuveitis). QFT was positive in nearly a fourth of the uveitis patients especially in the subgroup of intermediate, posterior and panuveitis. Anatomic localisation of the patients who tested positive were distributed as anterior n=12 (15%), intermediate n=22 (27.5%), posterior n=26 (32.5%) and panuveitis n=18 (22.5%). Of the 43 QFT+ patients, 16 were treated with full therapy following World Health Organisation (WHO) recommendations. QFT is a helpful tool in diagnosing uveitis but gives surprisingly high numbers of positives in
uveitis patients not sufficiently explained by immigrant status of the patients. This raises questions regarding treatment implications.

Reference

Three years of experience with quantiferon-TB Gold Testing in patients with uveitis.
Jakob E, Zimmerman S, Dalpe AH, et al.
OCCULAR IMMUNOLOGY AND INFLAMMATION
2014;22(6):478-84.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

A new technique for correction of medial ectropion with a lax medial canthal tendon
Reviewed by: James Hsuan
Vol 21 No 6
 

This is a prospective study of a new technique for repair of medial ectropion associated with medial canthal tendon (MCT) laxity. The procedure was performed on 79 eyes and involved excision of an ellipse of tissue from below the punctum including part of the caruncle medially, tarsal plate laterally and lower lid retractors inferiorly. The defect created was then closed with a circular purse-string type suture drawing the tarsus towards the caruncle and elevating the retractors. The authors make the point that extending the incision to include the caruncle exposes the posterior limb of the medial canthal tendon, and suturing the tarsus to this corrected the laxity and maintained the normal alignment of the lid to the globe. It is not clear why the purse string suture needs to be passed through the skin and tied over a bolster, as this implies the retractors have not been sufficiently advanced and an extra inward rotation of the lid margin is needed. Also a simultaneous lateral canthal tightening / repositioning procedure was required in 52 eyes which had significant residual lid laxity after the medial purse string was placed. These may both reflect the theoretical problem with the purse string suture which inevitably bunches up the tissue rather than reapposing the retractors to the tarsal plate in a vertical plane and the tarsus to the MCT in a horizontal plane. Despite this there are good results from this procedure, with 78% of those with epiphora having complete resolution of tearing. Medial ectropion associated with significant MCT laxity remains a surgical challenge, but this new technique deserves consideration based on the good outcomes reported.

Reference

Caruncular fixation in medial canthal tendon repair: the minimally invasive purse string suture for tendonous laxity and medial ectropion.
Czyz CN, Wulc AE, Ryu CL, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:34-7

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Better outcomes from early repair of Type B blow-out fractures
Reviewed by: James Hsuan
Vol 21 No 6
 

This paper examines whether early, rather than late, surgical repair results in better motility outcomes for a particular subgroup of orbital floor blowout fractures. The authors divide floor fractures into Types A and B, depending on whether or not the degree of soft tissue involvement is in proportion to the level of bone fragment displacement. They found in an earlier study that those that had soft tissue displacement out of proportion to the bone disruption, which they labelled Type B, were at greater risk of final reduced motility. They attributed this to constriction of the soft tissue and ongoing ischaemic injury until the fracture is repaired. This paper develops this hypothesis to see if early surgery can improve the final motility in Type B fractures. Twenty-five patients were included and it was found that those that had surgery within seven days had better final motility with larger fields of binocular single vision than those who were operated on later. It has long been appreciated that urgent surgery is indicated for trapdoor orbital floor fractures in children who may have oculo-vagal signs and ischaemia of prolapsed tissue. This paper expands on this theme to include all age groups, and emphasises the importance of recognising on the CT scan when the degree of soft tissue involvement is out of proportion to the bone fragment displacement. The authors have shown that early intervention in these patients will result in better long-term ocular motility. There may be some difficulty in deciding whether a particular fracture is Type A or B, and the study is let down by containing a mixture of prospective and retrospective data. There is no mention of how the timing of surgery was decided, which may be a source of bias. Despite these drawbacks, the paper makes a convincing argument with statistically significant results despite relatively small numbers.

Reference

Surgical timing and postoperative ocular motility in type B orbital blowout fractures.
Liao JC, Elmalem VI, Wells TS, Harris GJ.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2015;31:29-33.

OPHTHALMIC RESEARCH

Aqueous humour cytokine levels in PCV and nAMD
Reviewed by: Bheemanagouda Patil
Vol 21 No 6
 

This study looks into the possible roles of various cytokines or growth factors in the pathogenesis of exudative age-related macular degeneration (AMD) by comparing aqueous levels of 14 cytokines between eyes with polypoidal choroidal vasculopathy (PCV) and those with neovascular AMD. Forty eyes from 40 patients with treatment-naïve exudative AMD (neovascular AMD=18 and PCV=22) were studied. Twenty eyes from 20 patients with no retinal pathology who underwent cataract surgery served as controls. Aqueous samples were collected just before intravitreal ranibizumab injection in the study and before cataract surgery in the 20 control eyes. Concentrations of 14 cytokines were determined by chemiluminescence-based ELISA: interleukin (IL)-1α, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, vascular endothelial growth factor (VEGF), monocyte chemoattractant protein 1, interferon-γ-inducible protein (IP)-10 and C-reactive protein (CRP). After adjusting for gender, age and axial length, concentrations of CRP and IP-10 were significantly higher in eyes with neovascular AMD or PCV compared with control eyes (p<0.05), and IP-10 levels were strongly associated with lesion size (p=0.002). None of the 14 cytokines, including VEGF, were significantly different between eyes with neovascular AMD and those with PCV. Aqueous concentrations of CRP and IP-10 were elevated in eyes with PCV or neovascular AMD. IP-10 could be associated with the pathogenesis of neovascular AMD and PCV.

Reference

Aqueous humour cytokine levels in patients with polypoidal choroidal vasculopathy and neovascular age-related macular degeneration.
Sakurada Y, Nakamura Y, Yoneyama S, et al.
OPHTHALMIC RESEARCH
2015;53(1):2-7.

OPHTHALMOLOGICA

Intravitreal ranibizumab for the treatment of myopic CNV
Reviewed by: Sofia Rokerya
Vol 21 No 6
 

The authors conducted a prospective study. Sixty-four patients (65 eyes) attended the 12-month follow-up examination. The mean patient age was 47.8 years. Fifty-five patients (86.0%) were females. All patients had pathologic myopia (a spherical equivalent of more than − 6.0 diopters) with a new onset of predominantly classic choroidal neovascularisation (CNV) in the macular area associated with pathologic myopia (<2 months). By localisation 19% of CNVs were juxtafoveal (n=12) and 81% subfoveal (n=52). The median presenting visual acuity was equivalent to 0.2, and the mean baseline central retinal thickness was 313μm. These were treated with intravitreal ranibizumab 0.5mg. The regime consisted of two fixed loading injections, one at baseline and the second one month later. The indication for a third and further pro re nata (PRN) injections was based on the following reinjection criteria: visual acuity (loss of one line or more), development of new macular haemorrhage on fundus examination, evidence of late leakage on fluorescein angiography) and the presence of any fluid or any increase in macular thickness of >50μm on optical coherence tomography (OCT). The primary outcome was a change in BCVA compared to baseline at six and 12 months. The secondary endpoint was the change in central retinal thickness as per OCT from baseline to six and 12 months as well as safety, neovascularisation activity on FA and the number of ranibizumab injections applied. Compared to the baseline, best corrected visual acuity (BCVA) had improved significantly at all later points in time (p=0.001). The mean baseline BCVA was 0.2 (SD 0.13). At 12 months, it was 0.4 (SD 0.21). The greatest improvement in BCVA was seen within the first three months (p=0.0001). The mean central retinal thickness analysed by OCT showed a reduction from 313μm (SD 82) to 243.5μm (SD 31; p=0.0001). CNV closure rate was 61/65 (94) with 2.3 ±0.9 injections. There was a continuous decrease in mean OCT retinal thickness over time. Throughout the follow-up period, patients received an average number of two injections of ranibizumab. Traditional treatments for myopic CNV comprises of laser photocoagulation, transpupillary thermotherapy (TTT) and photodynamic therapy (PDT). These have been unsatisfactory, associated with structural damage, and have not offered long-term visual acuity benefits. Anti-VEGFS offer a better outcome. Intravitreal ranibizumab was been shown to be a safe and efficacious treatment option in myopic CNV. The study emphasises that visual acuity improvement was swift and could be maintained throughout the treatment study period. However, limitations of this particular study include a short-term follow-up.

Reference

Intravitreal ranibizumab for the treatment of choroidal neovascularizations associated with pathologic myopia: a prospective study.
Pasyechnikova NV, Naumenko VO, Korol AR, et al.
OPHTHALMOLOGICA
2015;233:2-7.

ORBIT

A diagnostic imaging technique for optic pathway tumours
Reviewed by: Konal Saha
Vol 21 No 6
 

The authors discuss the difficult clinical scenario of patients with deteriorating visual function and an optic pathway lesion. The morbidity associated with biopsy means a highly sensitive and specific imaging technique would be of great value. The authors describe the use of combined Ga-68-DOTA-TATE PET and CT to diagnose optic pathway meningiomas. The imaging technique relies on the expression of somatostatin receptors by meningiomas. The imaging technique was used to examine 13 patients with ambiguous, symptomatic optic pathway lesions. The results of the imaging were validated by histopathology in five patients and conventional clinical / radiological examination in the others. The authors conclude that Ga-68-DOTA-TATE PET/CT is a sensitive and specific imaging modality for distinguishing meningiomas (somatostatin receptor expressing) from other tumours.

Reference

Ga-68-DOTA-TATE PET/CT for discrimination of tumours of the optic pathway.
Klingenstein A, Haug AR, Miller C, Hintschich C.
ORBIT
2015:34(1);16-22.

ORBIT

Occult spread of squamous cell carcinoma into the orbit
Reviewed by: Konal Saha
Vol 21 No 6
 

The authors describe two cases that may represent perineural spread of cutaneous squamous cell carcinoma (SCC) into the orbit. Both cases had cutaneous squamous cell carcinomas in the region of the lateral orbital wall (innervated by the zygomatico-temporal nerve) which were excised. The patients presented some time later with masses in the lateral orbit which were biopsied and shown to be squamous cell carcinoma. At the time of presentation with the orbital masses, no skin or bony lesions were noted either clinically or on CT imaging. The authors suggest SCC presenting in the region of the lateral orbital wall may show perineural spread down the zygomaticotemporal nerve into the orbit with the orbital mass presenting sometime after excision of the skin lesion and without any detectable skin recurrence.

Reference

Silent squamous cell carcinoma invading the orbit following the course of the zygomaticotemporal nerve.
De Keizer ROB, de Wolff-Rouendaal D, de Keizer RJW.
ORBIT
2015;34(1):10-5.

RETINA

Hyper reflective foci (HRF) on OCT in diabetic retinopathy
Reviewed by: Saruban Pasu
Vol 21 No 6
 

This study investigated the presence of hyper reflective foci (HRF) in asymptomatic patients affected by type 1 or type 2 diabetes, separately, without clinically significant diabetic macular oedema and visual impairment. In total 71 eyes with non-proliferative diabetic retinopathy were imaged using SD OCT. Thirty-three eyes were from type 1 diabetics and 38 eyes from type 2 diabetics. The presence of HRF was defined as the presence of small focal hyper reflective areas scattered mainly in outer retinal layers but also spreading in all retinal layers observed in at least one SD OCT scan. Exclusion criteria included visual impairment, hard exudates or retinal haemorrhages in the fovea, previous retinal surgery / laser, high refractive error, evidence of macular oedema and signs of any other active retinal disease. Control groups of 15 young subjects and 13 older subjects were included for type 1 and 2 diabetics respectively. On SD OCT examination, intraretinal HRF were present in all patients affected by type 1 and type 2 diabetes as scattered punctiform dots invisible at clinical examination, fundus photography and in red free images. HRF amount was significantly higher in the diabetic patients compared to control groups. Type 1 diabetic patients had significantly less HRF than individuals affected by type 2 diabetes. They found patients with a poor quality glycometabolic control were associated with a larger presence of HRF. In the type 2 diabetic group, there was a significant correlation between HRF amount and the presence of hypertension. Sex, patient age and duration of the disease did not influence significantly the number of HRF within the retinal layers. The authors highlight other studies that reported the presence of HRF in the outer retina layers decreases visual acuity of subjects with diabetic macular oedema. Two theories are suggested as to the relevance of HRF; (1) a morphologic sign of accumulation of intraretinal fluid and lipid extravasation, and consequently precursors of hard exudates, and (2) an accumulation of inflammatory cells. The authors conclude by suggesting HFR may be a useful marker for the diagnosis of diabetic retinopathy in the early stage of the disease and an additional marker for the glycometabolic status of the patients.

Reference

Optical coherence tomographic hyper reflective foci in early stages of diabetic retinopathy.
De Benedetto U, Sacconi R, Pierro L, et al.
RETINA
2015;35(3):449-53.

RETINA

VEGF and axial length (RVU)
Reviewed by: Saruban Pasu
Vol 21 No 6
 

The authors of this paper set out to examine whether the concentrations of VEGF in the vitreous were associated with refractive error and axial length in eyes without retinal disease, except of macular holes or epiretinal membranes. A vitreous sample was obtained during 23-gauge pars plana vitrectomy on 34 patients (21 macular holes, 13 epiretinal membranes). Mean age was 62.4, mean IOP was 13.8, mean spherical equivalent was -3.26 +/- 4.23 dioptres (range, -17.50 to 1.50D) and mean axial length was 24.1 +/-1.8mm (range, 21.0 – 29.1mm). The intravitreal VEGF concentration was significantly lower than the VEGF concentration in the blood. Intravitreal VEGF concentrations were not significantly associated with gender or age. A higher intravitreal VEGF concentration was significantly associated with a shorter axial length and a higher hyperopic refractive error. Plasma concentrations of VEGF were not significantly associated with axial length or refractive error. These results are consistent with other studies showing that aqueous humour concentrations of VEGF were significantly and negatively correlated with axial length. The results of this study fit with the observations made in population-based and hospital-based studies that myopia is associated with the lower prevalence of exudative age-related macular degeneration, proliferative diabetic retinopathy, and branch retinal vein occlusion. VEGF may be more diluted in the larger vitreous cavity of eyes with a longer axial length than in the smaller vitreous cavity of eyes with a shorter axial length.

Reference

Intravitreal vascular endothelial growth factor concentration and axial length.
Hu Q, Liu G, Deng Q, et al.
RETINA
2015;35(3):435-9.

SEMINARS IN OPHTHALMOLOGY

Intravitreal injection related endophthalmitis
Reviewed by: Jayavani Myneni
Vol 21 No 6
 

This article reviews the incidence, clinical findings, risk factors, management and visual outcomes in intravitreal injection related endophthalmitis. Incidence of this complication is reported to be in the range of 0.038% to 0.065% (1 in 2000-3000 injections). Patients present typically within five days with reduced vision, pain and photophobia. Data shows a positive culture rate of 52-59.6% with the commonly isolated organism being coagulase negative staphylococcus. Rate of streptococcus isolation is higher (25% to 30%) in contrast to cataract surgery related endophthalmitis where it is 8.2-9%. This has been attributed to passage of respiratory tract flora during the injection procedure. The management of these patients by most practitioners was based on the general guidelines from Endophthalmitis Vitrectomy study. Most cases can be managed with vitreous tap and intravitreal antibiotics. Visual recovery was measured as percentage of patients recovering their pre-injection visual acuity. This outcome was dependent in part on the causative organism. Poorer outcomes were found in cases where streptococcus was isolated. One of the studies suggest that contamination of the injection site with upper respiratory flora such as streptococcus occurs when the patient, nurse or physician talk or cough during the procedure. The authors recommend that this be avoided. But there is no definitively proven benefit with the use of facemask. The use of perioperative antibiotic drops is not supported by enough data and the suggestion is that their widespread use may breed resistance in organisms. However, povidone iodine is consistently found to be effective. Bimanual assisted lid retraction is reported to increase patient comfort when compared to lid speculum without increasing any risk from lash contamination. Investigations of endophthalmitis reported after bevacizumab injections revealed that contamination occurred during the preparation of syringes at compounding pharmacies. This review article is a good summary of the current evidence and practices in management of intravitreal injection related endophthalmitis.

Reference

Endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor medications.
Haddock L, Ramsey DJ, Young LH.
SEMINARS IN OPHTHALMOLOGY
2014;29(5-6):257-62.

THE NEW ENGLAND JOURNAL OF MEDICINE

Aflibercept, bevacizumab or ranibizumab for diabetic macular oedema
Reviewed by: Jonathan C P Roos
Vol 21 No 6
 

Reference

CURRENT EYE RESEARCH

Conjunctival inflammation in glaucoma patients
Reviewed by: Khadijah Basheer
Vol 21 No 6
 

Numerous studies have demonstrated that topical medications and preservatives used for the management of glaucoma can induce significant histopathologic and inflammatory changes in the ocular surface. This study describes an increased expression of major histocompatibility complex class II antigen HLA-DR, used as a marker of inflammation, on conjunctival epithelial cells in patients treated with multiple BAK-preserved topical glaucoma medications, confirming the presence of conjunctival inflammation. This increase in HLA-DR expression correlated with an increase in extracellular metalloproteinase inducer (EMMPRIN) membrane expression. EMMPRIN has been shown to stimulate the production of several matrix metalloproteinases (MMP) in pathological situations such as corneal ulcers and dry eye. This study suggests an MMP mediated modification of the conjunctival extracellular matrix remodelling in glaucoma patients using multiple eye drops with BAK preservative. This is not only important in the symptoms patients experience, which can affect compliance but also has an impact on future management with glaucoma filtration surgery as conjunctival wound healing is a major determinant for its success.

Reference

Increased extracellular matrix metalloproteinase inducer (EMMPRIN) expression in the conjunctival epithelium exposed to antiglaucoma treatments.
Labbe A, Gabison E, Brignole-Badouin F, et al.
CURRENT EYE RESEARCH
2015;40(1):40-7.

EYE

Nonarteritic anterior ischaemic optic neuropathy
Reviewed by: Nana Theodorou
Vol 21 No 6
 

This review article describes nonarteritic anterior ischaemic optic neuropathy (NAION). This condition is one of the common causes of visual loss in adults. The article uses a good range of references and is divided under the headings of; demographics, clinical presentation, pathophysiology, pathogenesis, risk factors, cellular mechanisms, clinical course, differential diagnosis, diagnostic testing, therapy and prevention. NAION typically presents in patients over 50 years as acute painless unilateral visual loss associated with an inferior visual field defect, swollen optic disc and flame-shaped peripapillary retinal haemorrhages. Visual acuity tends to be better than 6/60 likely due to impaired blood flow in the optic nerve vasculature. Patients tend to have at least one underlying vascular risk factor such as nocturnal systemic hypotension, systemic hypertension or diabetes. The risk factor section is of particular interest and well referenced. NAION remains stable over time with some reported cases of spontaneous improvement. The role of differential diagnosis is highlighted and complemented by diagnostic testing. Although there is no consistent treatment for this condition the authors offer a detailed insight into published work and list the limitations of the current literature. Overall this article offers an excellent review of NAION.

Reference

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy.
Miller N, Arnold A.
EYE
2015:29:65-79.

INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

Brn3b neuroprotective effect in rat glaucoma model
Reviewed by: Wai Siene N
Vol 21 No 6
 

An adeno-associated virus-directed overexpression of the Brn3b protein in hypothesised to confer neuroprotective effects in this paper. This is ultimately tested in a well-accepted rat glaucoma model (Morrison’s model: saline injection into episcleral veins of rat eyes with a force sufficient to blanch the aqueous plexus with subsequent scarring of the trabecular meshwork). Viral transduction was firstly demonstrated by increased levels of Brn3b in primary retinal ganglion cell cultures, retinal explants and in the retina and optic nerve head of the rats with induced glaucoma. Neuroprotective effects in the experimental rat glaucoma model was indicated by increased survival of retinal ganglion cell counts and optomotor testing to represent visual function. Furthermore, the group demonstrated modest increased levels of GAP-43; a regulator of axon outgrowth, suggestive of increased neuronal plasticity. This was further supported by the suggestion of restoration of axonal transport which is usually disrupted in IOP-elevated rats eyes; shown by the presence of Alexa conjugated cholera toxin B (an anterograde transport tracer dye). Overall, this is a comprehensive well thought out paper with good promise for clinical translation.

Reference

Neuroprotective effect of transcription factor Brn3b in an ocular hypertension rat model of glaucoma.
Stankowska DL, Minton AZ, Rutledge MA, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2015;56(2):893-907.

INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

Implantation of intraocular pressure sensor in glaucoma patients
Reviewed by: Wai Siene Ng
Vol 21 No 6
 

The authors report safety and accuracy of an intraocular intraocular pressure (IOP) sensor placed in the ciliary sulcus during planned cataract surgery. Six patients underwent implantation of the device; a silicone rubber ring-shaped device encapsulating pressure sensitive capacitors and a microcoil antenna. To determine IOP the difference between the absolute pressure sensor in the eye and outside the eye measured by a reader unit held in front of the eye, is calculated. They report a well-tolerated device but rightfully highlight an area of grave concern whereby four out of six patients developed early postoperative sterile anterior chamber inflammation, with two displaying hypopyons. Furthermore, significant pigment dispersion was noted in 50% of patients and all patients showed pupillary distortion. With regards to accuracy, four patients with unexplained IOP shifts, which have been put down to malfunction or a pressure effect on the device during the healing process. The authors should indeed be given credit for their attempt at searching for a continuous IOP monitoring and self non-contact tonometry device. However, with the aforementioned safety issues, size of device necessitating a large corneal incision of about 5.5mm and inexplicable IOP shifts, it would be wise for the group to continue working on refining the sensor shape, size, accuracy and perhaps an alternate site for implantation so as not to impinge onto the uvea, i.e. capsular bag rim or as an IOL piggy back. Otherwise, the risks of an intraocular IOP device far outweighs that of an extraocular one.

Reference

Implantation of a novel telemetric intraocular pressure sensor in patients with glaucoma (ARGOS Study): 1-Year results.
Koutsonas A, Walter P, Roessler G, Plange N.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2015;56:1063-9.

JAMA OPHTHALMOLOGY

SLT vs. topical treatment with prostaglandin analogues in the management of PACG
Reviewed by: Lona Jawaheer
Vol 21 No 6
 

Selective laser trabeculoplasty (SLT) has been shown to be useful in the management of primary open angle glaucoma (POAG), but its use in primary angle closure (PAC) / primary angle closure glaucoma (PACG) has yet to be validated. Narayanaswamy et al. present the results of a randomised controlled study involving 100 patients with PAC / PACG having previously undergone laser peripheral iridotomies with subsequent opening of at least 180º of the angles. Fifty participants were randomly allocated to treatment with a topical prostaglandin analogue (PGA) and 50 to treatment with SLT in order to address baseline intraocular pressures (IOP) above 21mmHg. The results after a six month period of follow-up showed a decrease in IOP of 4.0mmHg with SLT vs. 4.2mmHg with PGA (p=0.78), and a percentage decrease in IOP of 16.9% with SLT vs. 18.5% with PGA (0.52). Following treatment, 60.0% of SLT patients had IOPs lower than 21mmHg without medications, compared to 84.0% of PGA patients (p=0.08). And 28.6% of patients receiving SLT were treated repeatedly, to address a reduction in IOP of less than 20%. Side-effects of SLT included a transient post-treatment IOP spike of greater than 5mmHg in one patient (2%), and a significant decrease of 4.8% in mean endothelial cell count (p=0.01). The authors also note the difficulty in performing 360º SLT (known to have the best IOP-lowering effect) owing to the anatomy in PAC / PACG. Side-effects of treatment with PGA included uveitis and allergic uveitis (4%) leading to interruption of treatment. This study shows that SLT does produce a decrease in IOP in patients with PAC / PACG which is comparable to that obtained with a PGA. Treatment with SLT in PAC / PACG presents the advantage of avoiding a long-term treatment with its associated cost, risk of non-compliance and its side-effects. However, a longer follow-up period is required to ascertain the long-term effects of SLT.

Reference

Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma. A randomized clinical trial.
Narayanaswamy A, Leung CK, Istiantoro DV, et al.
JAMA OPHTHALMOLOGY
2015;133(2):206-12.

JOURNAL OF GLAUCOMA

Eye drop prescription and usage in glaucoma patients
Reviewed by: Lorraine North
Vol 21 No 6
 

The authors describe a study using a questionnaire to determine how patients use their glaucoma medications to investigate the association between patterns of eye drop prescriptions and medication use. They enrolled 67 Japanese patients who had been prescribed topical anti-glaucoma medications including a prostaglandin bilaterally. Demographic data was collected, as well as number of bottles prescribed monthly and a five item questionnaire was used to evaluate eye drop administration. Their findings show that patients’ routine medication usage was significantly associated with the number of bottles prescribed monthly. The authors suggested that this was reflective for patients who tended to miss the eye when instilling the eye drops probably because of incorrect technique. Their results also showed that men or patients with mild glaucoma were less likely to be aware of local side-effects than women or patients with severe glaucoma. Limitations of the study include small sample size, practice pattern in Japan and the need for further prospective studies with a larger number needed.

Reference

A study of the association between patterns of eye drop prescription and medication usage in glaucoma subjects.
Kawai-Tsuboi N, Kawai M, Minami Y, Yoshida A.
JOURNAL OF GLAUCOMA
2015;24(3):202-6.

JOURNAL OF GLAUCOMA

Full thickness macular hole after YAG PI
Reviewed by: Lorraine North
Vol 21 No 6
 

The authors report a case of macular hole post YAG peripheral iridotomy (PI) of a patient with pre-existing vitreomacular adhesion. Although a relatively safe procedure, some anterior segment complications are well documented such as corneal endothelium damage, rise in IOP, iris bleed and lens damage. The authors report the case of a 64-year-old female who had an adherent leucoma in the right eye with occludable angles confirmed on indentation gonioscopy. Optical coherence tomography (OCT) was normal in the right eye and showed epiretinal membrane with vitreomacular adhesion in the left eye. The patient received prophylactic YAG PIs to both eyes and three days later complained of dimness of vision in the left eye with reduced vision to 6/36. Examination revealed a stage four full thickness hole requiring vitreoretinal surgery and the vision improved to 6/9. The authors describe the small number of previously reported posterior segment complications with only two being macular holes. The authors postulate that macular hole formation is due to the shock waves generated by Nd:YAG laser and that careful planning and counselling should be performed in such cases along with post PI posterior segment checks.

Reference

Unilateral full-thickness macular hole formation following low-energy Nd:YAG peripheral iridotomy.
Sar S, Sinha S, Mitra S.
JOURNAL OF GLAUCOMA
2015;24(3):e14-e15.

JOURNAL OF GLAUCOMA

IOP and reversibility of RPE detachment
Reviewed by: Lorraine North
Vol 21 No 6
 

The authors describe how three patients with retinal pigment epithelium (RPE) detachment showed a reduction or disappearance of an RPE detachment immediately following prone dark room test (PDRT). The authors performed spectralis OCT on 140 angle closure subjects before and after PDRT. Three patients showed a flattening or complete resolution of the RPE detachment with an acute rise and then fall in IOP. The authors describe the occurrence with short-term IOP changes only but further studies are needed to explore the concept and factors influencing such changes.

Reference

Reversibility of retinal pigment epithelium detachment parallel to acute intraocular pressure rise.
Wang YX, Ran J, Yang LH, et al.
JOURNAL OF GLAUCOMA
2015;24(3):e16-e18.

JOURNAL OF GLAUCOMA

Reproducible OCT RNFL map in unilateral glaucoma
Reviewed by: Lorraine North
Vol 21 No 6
 

The aim of the study was to compare the reproducibility of the optical coherence tomography retinal nerve fibre layer (OCT RNFL) thickness map between glaucomatous and fellow normal eyes of unilateral glaucoma patients. The authors carried out a prospective case controlled study enrolling 107 newly diagnosed unilateral glaucoma patients. Only those that had stable controlled IOP were included. The glaucomatous eye had typical optic nerve damage with typical visual field defect. OCT images were taken on the Cirrus HD-OCT. Seventy-nine Asian subjects were eligible of the 107 to be included. The authors concluded that the test-retest variability’s and tolerance limits of the Cirrus HD-OCT RNFL thickness map of the glaucomatous eyes were lower than the normal eyes. The authors suggest that adjusting the tolerance limits on the basis of the baseline RNFL thickness values might help improve the ability to recognise progression. Further prospective studies are needed as this study was carried out on all Asian ethnic group using scans of high image quality exclusively and authors advise that care should be taken when analysing poorer quality scans.

Reference

Reproducibility of spectral-domain optical coherence tomography RNFL map for glaucomatous and fellow normal eyes in unilateral glaucoma.
Suh MH, Yoo BW, Park KH, et al.
JOURNAL OF GLAUCOMA
2015;24(3):238-44.

JOURNAL OF GLAUCOMA

Visual recovery following Ex-Press vs. trab
Reviewed by: Lorraine North
Vol 21 No 6
 

The authors describe a prospective randomised study of 64 POAG subjects with controlled IOPs comparing visual acuity data in patients randomised to either Ex-Press model P50 or trabeculectomy. Visual acuities were recorded at baseline, day one, weeks one and two and month one, three and six postoperatively. Postoperative complications were recorded plus cup disc ratio and mean deviation on Humphrey Visual Fields. Vision loss was categorised as mild, moderate or severe. The results regarding IOP, central corneal thickness (CCT) and endothelial cell count were not included in this paper. All subjects completed three months follow-up and 61 completed six months. In both groups visual acuity was significantly reduced following surgery, however, the authors found no difference in mean visual outcomes between the two surgical groups. They did, however, find a faster visual recovery with the Ex-Press group compared with trabeculectomy. Their results are similar to other studies such as tube vs. trab as when the visual acuity was evaluated as a categorical variable rather than a continuous variable, those in the trab group lost >2 snellens lines at six months. No difference was found in complication rates. The limitations of the study are reported by the authors as they did not compare IOP between procedures and also visual acuity was measured un-refracted with a pinhole. Further investigation is also required to explore the aetiology further.

Reference

Comparison of visual recovery following Ex-press versus trabeculectomy: results of a prospective randomized controlled trial.
Beltran-Agullo L, Trope GE, Jin YP, et al.
JOURNAL OF GLAUCOMA
2015;24(3):181-6.

NEURO-OPHTHALMOLOGY

Abducens nerve palsy following surgical correction of craniosynostosis
Reviewed by: Claire Howard
Vol 21 No 6
 

The authors present two cases of unilateral abducens palsy secondary to a recent trans-sutural distraction osteogenesis (TSuDO) operation for craniosynostosis. The basic principle of the TSuDO procedure is described as dissection and distraction of the prematurely fused sutures. This complication following surgery has been rarely reported. In both cases the ocular motility deficit resolved over a two to four month period following removal of distractor. Possible mechanisms for this occurrence are discussed within the article. The authors suggest that a neuropraxic or stretch injury may have been the cause. They suggest that the two unusual cases they present may represent a combination of events following distraction osteogenesis producing shearing and / or stretching force of the abducens nerve, which reversed after removal of the distraction hardware.

Reference

Abducens nerve palsy following expansion cranioplasty with distraction osteogenesis.
Yoo H, Chung SA, Yoon SH.
NEURO-OPHTHALMOLOGY
2014;38(6):326-30.

NEURO-OPHTHALMOLOGY

Do operative interventions for IIH improve visual function?
Reviewed by: Claire Howard,
Vol 21 No 6
 

The authors of this paper reviewed patient case notes to determine visual outcome following shunt surgery for idiopathic intracranial hypertension (IIH). A retrospective case notes review was conducted for 50 patients who underwent shunt surgery for IIH. Outcome measures included decimal visual acuity and the mean radial degrees (MRD) of the 14e isopter of the Goldman visual field. These values were measured preoperatively and after a mean follow-up period of 1123 days. The mean number of surgical procedures for each patient was 2.8. The mean decimal visual acuity of the worse affected eye improved from 0.75 to 0.84. The MRD score of the worse affected eye improved on average from 25.6 to 35.5 degrees. In summary, shunting can improve visual function in patients with IIH. There is a need for a randomised controlled trial to further investigate operative interventions in IIH. The authors present a sample size calculation for such a trial.

Reference

Visual outcomes from shunting for idiopathic intracranial hypertension.
Hickman SJ, Raoof N, Panesar H, et al.
NEURO-OPHTHALMOLOGY
2014;38(6):310-9.

NEURO-OPHTHALMOLOGY

Rare case reports of benign optic glioma in adults with clinically aggressive nature
Reviewed by: Claire Howard
Vol 21 No 6
 

Primary optic nerve gliomas are most commonly benign and occurring in childhood. Malignant optic gliomas occur in adulthood and follow an aggressive course usually leading to blindness and death within months. This paper describes the clinical and histopathological features of clinically aggressive but histopathologically benign optic nerve gliomas of adulthood (a third category of optic glioma). Three cases of this rarely reported finding were selected for detailed study, including fundus photographs, visual field reports as well as MRI scan results. In all three cases, patients were initially diagnosed with optic nerve inflammation or benign neoplasm. They all went on to develop neuroradiological extension and all had a rapid deterioration of vision in the affected eye. Visual acuity deteriorated to no perception of light over a three to eight week period. The findings from these cases indicate that benign optic nerve gliomas in adults can be misdiagnosed as inflammation, be clinically aggressive and require excision to prevent further intracranial involvement.

Reference

Aggressive low-grade optic nerve glioma in adults.
Bilgin G, Al-Obailan M, Bonelli L, et al.
NEURO-OPHTHALMOLOGY
2014;38(6):297-309.

NEURO-OPHTHALMOLOGY

Surgical success rates in abducens palsy management
Reviewed by: Claire Howard
Vol 21 No 6
 

The aim of the study was to identify factors associated with surgical outcomes in isolated abducens palsy. To achieve this goal the authors reviewed the records of adult patients with abducens palsy who underwent strabismus procedures during a fourteen year period. Outcome measures included motor alignment, extraocular motility and sensory outcome. A successful outcome was defined for the purpose of this study as absence of diplopia without prisms or face turn, vertical deviation ≤2 prism dioptres (PD) and horizontal deviation ≤10PD. There were 81 patients included in the study and 58% achieved a successful outcome. Success rates varied dependent on the aetiology of the abducens palsy and patients with an underlying neoplastic or traumatic aetiology required more than one strabismus surgery procedure more often (compared with microvascular / idiopathic or other central nervous system causes). For complete abducens palsies, patients undergoing Hummelsheim type procedures had a higher success rate than those who underwent a full tendon vertical rectus muscle transposition. Overall, success rates for strabismus procedures are similar in patients across all aetiologies considered. Although this study has limitations with its retrospective design based on historical data, the information collected from a significant number of patients can provide valuable assistance when deciding on surgical invention options for patients with abducens palsy.

Reference

Functional and motor outcomes of strabismus surgery for chronic isolated adult sixth nerve palsy.
Peragallo JH, Bruce BB, Hutchinson AK, et al.
NEURO-OPHTHALMOLOGY
2014;38(6):320-5.

SEMINARS IN OPHTHALMOLOGY

Long scleral tunnel technique to prevent tube exposure of Ahmed glaucoma valve
Reviewed by: Jayavani Myneni
Vol 21 No 6
 

This retrospective study was done to evaluate the efficacy of long scleral tunnel technique and compare it with pericardium patch graft in preventing tube exposure of Ahmed glaucoma valve. Seventy-eight eyes of 73 patients were included. In group 1 patients, three parallel scleral incisions were made at 1.5-2mm, 6-8mm and 10-12mm away from limbus. A long scleral tunnel was prepared as two pockets one behind the other from these incisions. Paracentesis was done through the first scleral incision at the mouth of the tunnel. For group 2, pericardium patch graft was used to cover the tube. The mean age in both groups was comparable. Mean follow-up period in group 1 was 46.7 months and in group 2 was 43.6 months.Tube exposure was reported in one (2.5%) patient in group 1 at 25th month and three (7.9%) patients in group 3 at 21st, 27th and 30th months. The authors mention that the short follow-up period of the study is a limitation and suggest multicentre studies with longer follow-up periods. It is an interesting article highlighting the efficacy of an alternative approach to tube coverage which is very important to prevent endophthalmitis.

Reference

Efficacy of long scleral tunnel technique in preventing Ahmed glaucoma valve tube exposure through conjunctiva.
Kugu S, Erdogan G, Sevim MS, Ozerturk Y.
SEMINARS IN OPHTHALMOLOGY
2015;30(1):1-5.

THE NEW ENGLAND JOURNAL OF MEDICINE

A randomised, controlled trial of oral propranolol in infantile haemangioma
Reviewed by: Jonathan C P Roos
Vol 21 No 6
 

Since its use was first reported in the New England Journal in 2008, propranolol has become the preferred treatment for infantile haemangiomas. However, there is no consensus as to the optimum dose or duration of treatment and there is a paucity of formal trial data. The authors performed an international multi-centre double-blind placebo-controlled randomised trial. Using an ‘adaptive’ design, the efficacy of one or 3mg propranolol/kg body weight for either three or six months was compared. Out of these four possible groups one (the most efficacious) was then compared against placebo. To assess success, standard photos were taken at 24 weeks and submitted to a central panel of independent blinded investigators. Complete resolution or near-resolution at 24 weeks was classed as success whilst use of any other treatment or withdrawal from treatment was classed as failure. This was a large study – 456 infants were randomised – thus making it more than 10x larger than the largest earlier study. The interim analysis found that the highest dose and longest duration of treatment was best, and when this was compared to placebo the results were clear cut in favour of treatment: 60% vs. 4% resolution (p<0.001). Interestingly the length of treatment was important as there was little resolution after only three months treatment with either 1mg or 3mg, whilst 49% achieved resolution after six months treatment even with 1mg/kg strength (p<0.001). There were two main drawbacks with this study design: a) the most common dose used in clinical practice 2mg/kg/day was not tested but rather a higher and lower dose; b) as the design contained a placebo arm it was unethical to include severe haemangiomas and so these were excluded from the study. Though propranolol is an efficacious and safe treatment it can cause bronchospasm, bradycardia (usually within an hour of administration), hypotension and hypoglycaemia (and should therefore be given after a feed). Of the 400 or so patients receiving active treatment however, only one patient had a serious adverse event (bradycardia in the context of enterocolitis) but a single event did not reach statistical significance.

Reference

A randomized, controlled trial of oral propranolol in infantile hemangioma.
Léauté-Labrèze C, Hoeger P, Mazereeuw-Hautier J, et al.
THE NEW ENGLAND JOURNAL OF MEDICINE
2015;372:735-46.

ACTA OPHTHALMOLOGICA

Functional visual field loss using automated static perimetry
Reviewed by: Nana Theodorou
Vol 21 No 5
 

Functional visual field loss is traditionally assessed by kinetic perimetry, typically producing spiralling isopters. This study looked at the spatial distributions of functional field deficits using automated static perimetry. A retrospective review of automated perimetry records was conducted using a database to identify participants diagnosed with functional visual field loss. Thirty-six cases were found meeting the clinical and tangent screen criteria for functional visual field loss. Thirty-three normal eyes and 57 eyes with true lesions, including optic nerve compression, glaucoma, anterior ischaemic optic neuropathy and vigabatrin toxicity, served as controls. Perimetry consisted of high-pass resolution perimetry using vanishing resolution targets at 50 test locations inside 30 degree eccentricity. The results of standard automated perimetry statistics were unable to reliably discriminate organic versus non-organic visual field loss. Subjective evaluation of visual field results showed that functional fields generally could be identified by the presence of severe and irregular contractions and depressions as well as one or more isolated threshold ‘spikes’, that is, isolated locations showing much better than average sensitivity. On repeated examinations functional field loss was variable between examinations. In the absence of kinetic perimetry, functional visual loss can be identified by automated static perimetry. Useful criteria include severe and irregular contractions and depressions, the presence of isolated threshold spikes and poor inter-test correlations.

Reference

Identification of functional visual field loss by automated static perimetry.
Frisen L.
ACTA OPHTHALMOLOGICA
2014;92:805-9.

BRITISH JOURNAL OF OPHTHALMOLOGY

Orbital cellulitis in Scotland: current incidents, aetiology, management and outcomes
Reviewed by: Jonathan Chan
Vol 21 No 5
 

This is a one year prospective study using the Scottish ophthalmic surveillance unit reporting system amongst Scottish ophthalmologists. Only patients residing within Scotland with a new diagnosis of orbital cellulitis between November 2011 and October 2012 were including in this study. The overall total response rate was 66.4%. In total there were 20 reported cases in the study period affecting six females and 14 males. Fifteen of the 20 cases (75%) were in-patients aged less than 15 years (paediatric group) and five cases (25%) occurred in patients over 17 years (adult group). Within the paediatric age-group, six children (40%) were less than five years old, three children (20%) were between five and 10 years old and six children (40%) were 11 to 15 years old. The overall minimum incidence of orbital cellulitis in Scotland was estimated at 1.6 per 100,000 population in children 0 to 15 years and 0.1 per 100,000 in adults. Seven of the 15 children (47%) had a preceding upper respiratory tract infection and sinus involvement was confirmed by CT scan in 13 of the 15 (87%) children. In comparison, no adult had a pre-existing reparatory infection; one adult was immuno compromised due to haematological malignancy and two adults had preceding trauma. One had preceding facial trauma and one had an intraorbital foreign body and endophthalmitis. The pathogens were isolated in 70% of the cases. Streptococci species and emopholus inferenzie were the most frequently isolated pathogens in children and polymicrobial infection was common. In comparison, single organisms were isolated in adults. All patients received intravenous antibiotics on admission, dual therapy with a third generation cephalosporin and Flucloxacillin were the most common empirical therapy in nine cases, followed by triple therapy with addition of metronidazole in four cases. One adult and a child were treated empirically with a co-amoxiclav monotherapy. Five patients received other dual or triple therapy with various antibiotic classes. All patients underwent CT-imaging. Twelve children (80%) and three adults (60%) had an abscess identified on CT-scanning. Within the paediatric group, five (33%) children had orbital abscesses, five (33%) had sub-periosteal abscesses (SPA) and two (13%) had both orbital and SPAs. Three adults had orbital abscesses only. All children with abscesses and two adults with abscesses underwent surgical intervention. One adult with an orbital abscess had no surgery and recovered with orbital antibiotics alone. Of those who were surgically drained, there was variation in the extent of drainage received; external drainage of abscess alone in seven patients (47%), sinus surgery alone in three patients (20%) and combined drainage of abscess and sinus surgery in four patients (27%). All children completely recovered with no serious adverse outcomes. In the adult group, one patient had intracranial spread of infection with cranial surgical input and the patient with preceding intraorbital trauma and ophthalmitis progressed to evisceration. At three months, three adults were discharged. Of the two remaining under care, one had undergone evisceration and the other had leukaemia with diffuse orbital and lacrimal infiltrate. The authors conclude that this is the largest series of orbital cellulitis reported from the UK. Orbital cellulitis occurs more commonly in children than adults; sinusitis is the major preceding factor in children and adults are more likely to have trauma and comorbidities. The current practice in Scotland is to surgically manage all paediatric SPAs and orbital abscesses, even in those less than nine years of age. Streptococcus species are the most common pathogens in children. Influenza appears to be emerging as a frequent pathogen. Respiratory track organisms are less predictable pathogens in adults, depending on preceding trauma and commodities.

Reference

Orbital cellulitis in Scotland: current incidents, aetiology, management and outcomes.
C Murphy, Livingstone I, Foot B, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:1575-8.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Nasolacrimal duct screening to minimise post cataract endophthalmitis
Reviewed by: Anjali Gupta
Vol 21 No 5
 

This case control study compared the nasolacrimal duct (NLD) patency in a random sample of phacoemulsification cataract surgery patients (control group) versus a consecutive series of patients who developed endophthalmitis post cataract surgery (case group). NLD syringing was performed in both groups of patients. If the NLD was not patent on syringing, then a macro-dacryocystogram (MDCG) was performed. In the control group 11.8% (4/34 eyes) had NLD obstruction on syringing vs. 50% (5/10 eyes) in the endophthalmitis group (P=0.018). The rate of radiologically confirmed NLD obstruction on MDCG was lower at 2.9% in the control group vs. 20% in the endophthalmitis group (P=0.125). The authors conclude that NLD obstruction is a significant risk factor for postoperative endophthalmitis, therefore screening for symptoms and examination of the lacrimal system prior to cataract surgery is recommended.

Reference

Nasolacrimal duct screening to minimize post-cataract surgery endophthalmitis.
Kam JK, Cheng NM, Sarossy M, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:447-51.

CURRECT EYE RESEARCH

Precision and accuracy of TearLab osmometer
Reviewed by: Khadijah Basheer
Vol 21 No 5
 

Measuring tear osmolarity has been identified as a potential method for objectively diagnosing dry eye. TearLab osmolarity system is an in situ osmometer which may be a promising candidate for clinical use as it is portable and only requires a 20nL sample. However, some studies have obtained conflicting results regarding the accuracy of this system. This study examined the precision and accuracy of the TearLab system using 10 different salt solutions of varying osmolarity compared to a freezing point depression osmometer. Their results showed that the TearLab system can precisely and accurately measure osmolarity of salt solutions, but larger differences were found between the two methods at both extremes of osmolarity. Furthermore, this was an in vitro study and therefore was not influenced by any external factors that have led to the large repeatability coefficients in other studies including the time of measurement, differences in observer techniques and possible change in osmolarity from disrupting the tear film. The authors state that more studies need to be performed, ideally in vivo before TearLab can be considered as clinically useful. Firstly, there is a significant overlap in osmolarity between mild to moderate dry eye patients and normal controls and therefore any osmolarity value for diagnosis may lead to low sensitivity and a high false negative rate. Secondly, patients with dry eye have significant variability that is greater than normal controls and this may reduce the ability of TearLab to monitor disease progression.

Reference

Precision and accuracy of TearLab osmometer in measuring osmolarity of salt solutions.
Yoon D, Gadaria-Rathod N, Oh C, Asbell P.
CURRECT EYE RESEARCH
2014;39(12):1247-50.

EYE

Glaucoma prevalence in sleep apnoea
Reviewed by: Nana Theodorou
Vol 21 No 5
 

Obstructive sleep apnoea (OSA) is a disorder characterised by brief interruptions of breathing during sleep and results from complete or partial collapse of the pharyngeal airway. This study investigated the prevalence and progression of glaucoma in 39 patients receiving treatment for OSA. Participants were over 30 years and had been diagnosed with moderate and severe OSA in the sleep clinic at Hamad General Hospital in Qatar. The severity of OSA was graded as mild, moderate, or severe based using the apnoea hypopnea index. All patients underwent ophthalmological examination including visual field testing, optical coherence tomography and pachymetry. Study patients were followed up in the ophthalmology and sleep clinics for a period of three years at six monthly intervals. Most patients were male with a mean age of 52 years; 27 patients had severe and 12 moderate OSA. Examinations found that eight (20%) of the 39 OSA patients had glaucoma. Six of these patients had normal-tension glaucoma and two had high-tension glaucoma. Among the 27 patients with severe OSA, seven had glaucoma, and among 12 patients with moderate OSA, one had glaucoma. There was a prevalence of glaucoma in the severe OSA group compared with the moderate OSA group without statistical significance (P=0.4). The results of this small scale study confirm previous findings that severe OSA is a risk factor for glaucoma.

Reference

Prevalence of glaucoma in patients with moderate to severe obstructive sleep apnea: ocular and morbidity outcomes in a 3 year follow-up study.
Hasjim SP, Al Mansouri FA, Farouk M, et al.
EYE
2014;28:1304-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Ametropic amblyopia and stereopsis
Reviewed by: Fiona Rowe
Vol 21 No 5
 

This study aimed to evaluate the correlations between ametropic amblyopia (hypermetropic – 110, myopic – 30, and astigmatic – 65) and stereopsis in 205 children – mean age of 5.2 years ±1.8. For near stereopsis, significant results were found for mild and moderate amblyopia across myopia, astigmatism and hypermetropic refractive errors. Children with hypermetropia had better central stereopsis and macular stereopsis than those with myopia or astigmatism. Children with astigmatism had a significant reduction in stereopsis versus those with myopia and hypermetropia. Reduced stereopsis was seen in those with severe amblyopia. There was no significance for distance fusion range across groups. The authors conclude that types and degrees of amblyopia are closely related with stereopsis. Those with astigmatism were worst and the authors proposed more attention should be paid to treatment of this form of amblyopia.

Reference

Stereoscopic visual acuity in types of ametropic amblyopia in children.
Li S, Zon H, Wei C.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:105-10.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Childhood headaches
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The goal of this study was to compare headache resolution in children receiving or not receiving refractive correction. The authors conducted a retrospective review of 158 patients: 78 male and 80 female aged three to twelve years (mean eight). Twenty-seven percent had clinically significant refractive errors or had previously been prescribed glasses. It showed 30.4% had ophthalmic history other than refractive error including strabismus, convergence insufficiency, Duane’s retraction syndrome, amblyopia, nasolacrimal duct obstruction, functional visual loss, allergic conjunctivitis, retinopathy of prematurity, nystagmus, optic disc anomaly, anisocoria and ectopic lentis. Eighteen percent had a family history of migraine. Fourteen percent had temporal association of headache with reading, TV, computer use and homework. Nine and a half percent complained of blurred vision or diplopia. A new or altered prescription was given to 21% and prior glasses stopped for 2.5%. Follow-up information was obtained for 110 patients. It showed 76.4% had resolution or significant improvement. Migraine was later diagnosed for five patients. No significant difference in resolution was found for those who received a change in prescription versus those who did not. The authors concluded that most children with headache do not have ophthalmic abnormalities

Reference

Headache and refractive errors in children.
Roth Z, Pandolfo KR, Simon J, Zobal-Ratner J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:177-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Choroidal defects in neurofibromatosis
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The aim of this study was to investigate the frequency of choroidal abnormalities using infrared reflectance imaging with optical coherence tomography (OCT) in paediatric patients with neurofibromatosis (NF) type 1. Thirty-eight eyes of 19 patients were reviewed. NF1 was diagnosed by NIH criteria. Mean age was 8.63 years ±3.15. Hyper-reflective choroidal abnormalities were found in 15 patients (78.9%). A positive correlation was found between the number of choroidal abnormalities of both eyes and patient age. Iris hamartomas (Lisch nodules) were found in nine patients (47.4%). Choroidal abnormalities were present in all patients with Lisch nodules. Conventional fundus examinations and colour fundus photography did not reveal any abnormalities. Choroidal abnormalities were most often observed at the posterior pole. The authors propose infrared reflectance imaging with OCT is a useful aid in the diagnosis of NF1.

Reference

Frequency of choroidal abnormalities in pediatric patients with neurofibromatosis type 1.
Goktas S, Sakarya Y, Ozcimen M, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:204-8.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Postoperative astigmatism
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The authors investigate the short and long-term postoperative refractive effects of medial rectus recession on the involved eye and explain the detectable effects in detail by the results of vector analysis in 52 eyes and 32 patients. The subjects had a mean age of 8.6 years ±7.8. The results showed a significant difference between the preoperative and one month postoperative spherical equivalent values and the one month and one year values. There was a significant difference between the one month and one year postoperative values of cylinder dioptres and significant differences for surgically induced astigmatism, magnitude of error, flattening effect and astigmatism axis. A myopic shift of approximately 0.5D was seen at one month postoperative and a hypermetropic shift of 0.32D seen at one year postoperative. Changes at one month were considered to be associated with alterations in tension applied by the recessed muscle on the cornea. The effect disappeared by one year.

Reference

Surgically induced astigmatism following medial rectus recession: short term and long term outcomes.
Kutluturk I, Eren Z, Koytak A, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:171-6.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Resection versus advancement for consecutive XT
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The authors performed a retrospective review of results for patients treated with resection for consecutive exotropia in comparison to patients treated with advancement to the original insertion. The age of the resection and advancement groups averaged 33.6 and 38.2 years respectively. The mean preoperative angle was 32.3 for the resection group and 36.2 prism dioptres for the advancement group. Postoperative angle was 11.5 in the resection group and 11.4 prism dioptres in the advancement group. Forty-seven percent of the resection group and 63% of the advancement group achieved alignment within 10 prism dioptres of ortho. The results showed no significance between both groups and the authors conclude both surgical methods are useful.

Reference

Treatment of consecutive exotropia: unilateral lateral rectus recession combined with medial rectus advancement or resection.
Mangla D, Simon JW, Mangla N, Zobal-Ratner J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:116-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Results of changed treatment for retinoblastoma
Reviewed by: Fiona Rowe
Vol 21 No 5
 

Systemic chemotherapy was adopted in Kobe in 1996. In this study the authors analyse the clinical manifestations and results of treatment for patients with retinoblastoma since then. This review is of 43 eyes of 34 patients. Those with follow-up to a minimum of one year were included – 25 monocular and nine binocular cases with a median age at first examination of 13 months (22 days to six years and two months). Three patients had a family history of retinoblastoma. The youngest case was one of these three children. The mean observation period was 10.6. months ±53 (16-211). Clinical presentation at first examination included leukocoria (33) and exotropia (one). There was no correlation between age at first examination and classification stage of retinoblastoma. Nineteen eyes were in the initial enucleation group and 24 eyes in the initial preservation plan. Of the latter, 11 eyes continued preservation and 13 discontinued. Of the preservation cases, seven were enucleated because of poor tumour reduction, five showed tumour recurrence, one was enucleated due to secondary glaucoma, one developed secondary cataract and one patient had multi-organ metastases and died. Systemic chemotherapy with vincristine after 2000 had slightly better outcomes than that with ifosfamide before 1999. The study demonstrated that in cases that eventually need enucleation, chemotherapy can significantly delay this with the advantage that the orbit and eyelid can develop normally first and thus reduce the occurrence of facial defects caused by orbit and lid deformities following early enucleation. Eye preservation treatment was performed for a higher proportion of advanced cases among bilateral cases than monocular cases.

Reference

Clinical manifestations and treatment of retinoblastoma in Kobe Children’s Hospital for 16 years.
Okimoto S, Nomura K.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:222-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Results of single muscle advancement surgery
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The aim of this study was to determine quantitatively the efficacy of medial and lateral rectus muscle advancement in consecutive exotropia and esotropia. The authors analysed the relationship between the change in muscle position and the change in visual angle deviation. Eleven children with exotropia and esotropia were recruited with a mean age of 7.4 years ±1.9. Secondary surgery was undertaken at 17.7 years ±12.4 for esotropia and 62 years ±24.1 for exotropia. Success was defined as a deviation <10 prism dioptres at one week post-op. The average correction ratio for all cases was 4.31 dioptres per mm. The larger the preoperative angle and amount of rectus advancement, the greater the surgical dose effect. No postoperative duction or version limitations were noted. The results suggest single muscle advancement is sufficient to correct most cases.

Reference

Surgical dose-effect relationship in single muscle advancement in the treatment of consecutive strabismus.
Kim BH, Suh SY, Kim JH, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:93-9.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Review of paediatric infectious endophthalmitis
Reviewed by: Fiona Rowe
Vol 21 No 5
 

This paper presents a review on paediatric infectious endophthalmitis and considers aetiology, prognosis and management. Classification included exogenous and endogenous. Diagnosis was based on presenting history, signs and symptoms, cultures and imaging. Exogenous cases included postoperative endophthalmitis (strabismus surgery, glaucoma surgery, trabeculectomy with antimetabolite use, glaucoma drainage implants, cataract surgery, penetrating keratoplasty, pars plana vitrectomy) and post traumatic endophthalmitis. Management options included intravitreal antibiotics, systemic antibiotics, topical and subconjunctival antibiotics and corticosteroids. The review also considers management of fungal endophthalmitis, visual prognosis and complications. The authors conclude this is a rare condition often associated with very poor outcome. Open globe trauma and glaucoma surgery are the most frequent causes in children. Endogenous infections are least common. Streptococcus and staphylococcus are common bacterial agents in traumatic and surgical cases whereas candida albicans is common in endogenous endophthalmitis.

Reference

Pediatric infectious endophthalmitis: a review.
Khan S, Athwal L, Zarbin M, Bhagat N.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:140-53.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Suture tensile strength
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The effect of solutions commonly used in strabismus surgery were evaluated on 6-0 polyglactin suture tensile strength. The method involved a simple dead load test. Specimens of 6-0 suture were loaded in tension until breakage. This was repeated on 10 samples. The test was then repeated after soaking in solution for 30 minutes in normal saline, 5% povidone-iodine solution and 0.5% chlor solution. There was no significant difference between groups. The authors concluded there was no change in tensile strength of 6-0 polyglactin suture after immersion in various solutions.

Reference

The effect of commonly used surgical solutions on the tensile strength of sutures.
Rompat R, Jain S.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:189-90.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Three muscle surgery results for ET
Reviewed by: Fiona Rowe
Vol 21 No 5
 

There is limited information in the literature on the outcomes of three muscle surgery. The authors aimed to evaluate the medium term motor outcomes of three horizontal muscle surgery in 18 patients with large angle infantile esotropia of at least 55PD. The median age at surgery was 22 months (10-168). Only one child had limited lateral gaze postoperatively. The mean preoperative angle was 68.8 PD ±9.54 which reduced to 1PD (esotropia 30 to exotropia 4). Medial rectus recession was 5-6.5mm and lateral rectus resection was 7-8mm. Results within ≤10PD were achieved in 78% of cases. There was a median follow-up of 32 months (5-63). One patient needed two additional surgeries for vertical deviation. Four patients needed second surgery for residual esotropia. The mean dose / response ratio was 3.32±0.62PD/mm. The authors conclude there is a good rate of success in short and medium term. Overcorrection was not a serious problem but under correction can still occur.

Reference

Medium term outcomes of three horizontal muscle surgery in large angle infantile esotropia.
Bayramlar H, Karadag R, Yildirim A, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:160-4.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Vici syndrome
Reviewed by: Fiona Rowe
Vol 21 No 5
 

Vici syndrome is a condition associated with agenesis of the corpus callosum, congenital cataract, incomplete albinism, ± immunodeficiency and cardiomyopathy. Individuals show profound hypotony and severe neuro abnormalities. This paper reports a case of Vici syndrome. A 38-month-old female had bilateral nuclear and anterior polar cataracts and bilateral optic nerve atrophy. Visual interaction improved after left cataract extraction and anterior vitrectomy. This child was quiet, placid and profoundly hypotonic. She had fair skin and lightly pigmented blond hair, blue irides and normal sclera, long eyelashes, mild bitemporal narrowing, narrow palate and parallel transverse palmar creases bilaterally. VEP demonstrated misrouting of optic nerve pathways. OCT showed a poorly defined fovea with lesser degree of foveal depression. VEP was reported to aid the diagnosis of the case.

Reference

Ophthalmologic features of Vici syndrome.
Filloux FM, Hoffman RO, Viskochil DH, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:214-20.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

William’s syndrome
Reviewed by: Fiona Rowe
Vol 21 No 5
 

William’s syndrome is a congenital multisystem disorder involving the cardiovascular, connective tissue and central nervous systems. The aim of this study was to evaluate the frequency and severity of ophthalmic manifestations and associated diseases as well as provide epidemiology data in patients with this syndrome. This was a longitudinal prospective observation study of 30 patients whose diagnosis was confirmed by fluorescence in situ hybridisation (FISH) test. The study included 15 females and 15 males with an average age of 14.5 years ±1.38. Fifty-seven percent were white, 33% mixed race and 10% black. All presented with a typical face, delayed development and mental retardation, friendly personality and dental and skeletal abnormalities. Fifty percent had glasses before first ophthalmic examination. Seventy-seven percent had refractive error of which hypermetropia was most common in 67%, followed by astigmatism (20%) and myopia (7%). It showed 84% had a best corrected visual acuity of 20/20 with only one case of amblyopia with 20/50 acuity. Also 23% had epicanthus, 10% had stellate patterns of the iris and 36.7% had strabismus (30% esotropia and 6.7% exotropia). Seventy percent had normal ocular motility whilst 27% had oblique muscle over action and 3% had oblique muscle under action. Abnormal binocular vision was found in 43%. Diffuse arterio-venous tortuosity was noted in 27%.

Reference

William’s syndrome: ophthalmological examination and review of systemic manifestations.
Weber SLP, Souza RB, Ribeiro LG, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:209-13.

JOURNAL OF REFRACTIVE SURGERY

Visual performance of new multifocal IOL
Reviewed by: Mrinal Rana
Vol 21 No 5
 

Multifocal IOLs (MIOLs) keep evolving to try and get the best outcome in terms of vision and reduction of side-effects. This prospective interventional study was carried out on 34 eyes of 17 patients (11 women (65%) and six men (35%)) with mean age of 64 years (SD - 12.8; range 42-84 years). All patients were enrolled under strict exclusion criteria making sure that no other ocular pathology was found, which could have an effect on the visual prognosis. They underwent binocular sequential surgery under topical anaesthesia using standard suture less phacoemulsification technique and the new bi-aspheric, segmented, multifocal intraocular lens was inserted. Outcome measures checked were manifest refraction, uncorrected and corrected distance and near visual acuity; defocus curves in photopic conditions; contrast sensitivity; halometry as an objective measurement of glare and patient satisfaction questionnaires. Mean residual refraction was –0.13(±0.51) dioptres (D). Twenty-five eyes (74%) were within the mean spherical equivalent of ±0.50D. Mean uncorrected distance acuity was +0.10±0.12 logMAR monocularly and 0.02±0.09 logMAR binocularly. Thirty-two eyes (94%) could read 0.3 or better without any reading correction and all patients could read 0.3 or better with the near correction. Mean monocular uncorrected near visual acuity was 0.18±0.16 logMAR, improving to 0.15±0.15 logMAR with distance correction. Mean binocular uncorrected near visual acuity was 0.11±0.11 logMAR, improving to 0.09±0.12 logMAR with distance correction. Mean binocular contrast sensitivity was 1.75±0.14 log units at three cycles per degree, 1.88±0.20 log units at six cycles per degree, 1.66±0.19 log units at 12 cycles per degree, and 1.11±0.20 log units at 18 cycles per degree. Mean binocular and monocular halometry showed glare profile of less than 1° of debilitating light scatter. Therefore the M plus MIOL has been found to be an effective method of providing good distance acuity and near vision. Further studies with extended follow-ups were suggested to get to know about the full potential of this premium implant.

Reference

Visual performance of a new bi-aspheric, segmented, asymmetric multifocal IOL.
Berrow EJ, Wolffsohn JS, Bilkhu PS, Dhallu S.
JOURNAL OF REFRACTIVE SURGERY
2014;30(9):584-8.

OPHTHALMOLOGY

Intravitreal dexamethasone implant for diabetic macular oedema
Reviewed by: Brian Ang
Vol 21 No 5
 

The authors report on the three-year outcomes of the Ozurdex Dexamethasone (DEX) intravitreal implant multi-centre trial for the treatment of diabetic macular oedema (DME). Patients with DME (best-corrected vision of 20/50 to 20/200 and central retinal thickness of ≥300µm) were randomised in a 1:1:1 ratio to DEX implant 0.7mg, DEX implant 0.35mg or sham. Exclusion criteria included uncontrolled diabetes, concurrent use of systemic steroid, glaucoma, active neovascularisation, history of intraocular laser or surgery within 90 days, intravitreal anti-VEGF injection within 90 days, and intravitreal triamcinolone injection within 180 days. There were 1048 patients enrolled, but only 607 (57.9%) completed the three year study duration. The average number of treatments was 5.0 in the DEX implant 0.7mg group, 5.2 in the DEX implant 0.35mg group, and 5.1 in the sham group. In terms of visual acuity improvement of >15 letters, this was achieved in 22.2% of the DEX implant 0.7mg group, in 18.4% of the DEX implant 0.35 group, and in 12.0% of the sham group. The average reduction in central retinal thickness was 111.6µm in the DEX 0.7mg group, 107.9µm in the DEX 0.35mg group, and 41.9µm in the sham group. The commonest complications were elevated intraocular pressure (IOP) and cataract. IOP elevation requiring topical medication occurred in 41.5% in the DEX 0.7mg group, 37.6% in the DEX 0.35mg group, and 9.1% in the sham group. Cataract surgery was required in 59.2% of phakic eyes. In comparison to sham, the Ozurdex intravitreal implant show significant visual improvement and reduction in central retinal thickness. The side-effect profile was less in comparison to those previously reported for intravitreal fluocinolone and triamcinolone, but still significant nonetheless. A trial comparing Ozurdex to intravitreal anti-VEGF injections for DME will help to establish whether the benefit of reduced numbers of injections is outweighed by the significant side-effect profile.

Reference

Three-year, randomized, sham-controlled trial of dexamethasone intravitreal implant in patients with diabetic macular oedema.
Boyer DS, Yoon YH, Belfort Jr B, et al.
OPHTHALMOLOGY
2014;121:1904-14.

OPHTHALMOLOGY

Medical management and diabetic retinopathy progression
Reviewed by: Brian Ang
Vol 21 No 5
 

The ACCORD Eye Study was designed to evaluate the benefit of intensive glycaemic control (HbA1c <6.0% vs 7.0-7.9%), intensive systolic blood pressure control (<120mmHg vs. <140mmHg), and combined fenofibrate and simvastatin therapy in the development and progression of diabetic retinopathy. There were 3472 type 2 diabetic patients enrolled, and 2856 returned for examination at four years. The mean age of patients was 62 years, while the average duration of diabetes was 10 years. Blood pressure control did not have any effect on diabetic retinopathy progression. In contrast, intensive glycaemic control and fenofibrate treatment were both shown to reduce diabetic retinopathy progression. Interestingly, fenofibrate showed no benefit in eyes that did not have any diabetic retinopathy to start with. The results of this study have to be balanced in the context of intensive glycaemic treatment being associated with a 22% higher risk of death (5.0% vs. 4.0%) and three times higher risk of hypoglycaemic episodes (10.5% vs. 3.5%) compared with standard glycaemic treatment.

Reference

The effects of medical management on the progression of diabetic retinopathy in persons with type 2 diabetes. The action to control cardiovascular risk in diabetes (ACCORD) eye study.
Chew EY, Davis MD, Danis RP, et al.
OPHTHALMOLOGY
2014;121:2443-51.

OPHTHALMOLOGY

Methotrexate and mycophenolate mofetil for non-infectious uveitis
Reviewed by: Brian Ang
Vol 21 No 5
 

This is the first reported randomised clinical trial comparing methotrexate versus mycophenolate mofetil (MMF) for the treatment of non-infectious intermediate uveitis, posterior uveitis or panuveitis. To be eligible for recruitment, patients had to be on ≥15mg oral prednisone and demonstrated a previous history of steroid taper failure. Additionally, the patients should not have had any previous exposure to immunosuppressants, intraocular surgery in the past 30 days, fluocinolone acetonide implant surgery in the past three years, and periocular or intravitreal corticosteroid injection in the past 90 days. A total of 80 patients were randomised to either 25mg a week oral methotrexate or 1g twice daily oral MMF. If the medication was not tolerated, patients were allowed to adjust their study dose. Sixty-seven patients (35 methotrexate; 32 MMF) completed the six month study period. There were no statistically significant differences in terms of the time to steroid-sparing control of inflammation, change in best-corrected visual acuity, resolution of macular oedema, adverse events, or tolerability. Treatment success was achieved in 69% of methotrexate patients and 47% of MMF patients, but this difference did not achieve statistical significance (P=0.09). The results from this study seem to contrast with that from other retrospective studies, and is likely to have cost implications due to the significantly higher price of MMF.

Reference

A randomized clinical trial comparing methotrexate and mycophenolate mofetil for non-infectious uveitis.
Rathinam SR, Babu M, Thundikandy R, et al.
OPHTHALMOLOGY
2014;121:1863-70.

RETINA

Prognostic information for PRP-naive patients
Reviewed by: Saruban Pasu
Vol 21 No 5
 

The Diabetic Retinopathy Study group demonstrated that pan retinal laser photocoagulation (PRP) reduces severe vision loss by up to 50% in cases of proliferative diabetic retinopathy (PDR). The authors of this current study aimed to provide information for laser naive patients regarding the risk of future vitrectomy based on clinical examination findings. A retrospective review was carried out on 374 eyes principally noting the date of initial PRP and dates / incidence of vitrectomy. Patients were divided into three groups: Group 1 (PDR alone) n=185, Group 2 (PDR  and VH) n=160, Group 3 (PDR with neovascularisation of the iris [NVI], VH and traction, VH and fibrosis, or fibrosis alone) n=29. The percentage of eyes undergoing vitrectomy within one year was 9.73%, 26.9% and 37.9%, respectively. Within two years the percentage of eyes were 15.7%, 34.4% and 48.3%, respectively. Group 2 patients were 2.78 times and Group 3 were 3.54 times more likely than Group 1 patients to undergo vitrectomy within two years. Findings such as VH or fibrosis at initial PRP were found to be statistically significant in influencing the incidence of vitrectomy within two years. Patients not on insulin therapy were 1.74 times more likely to require vitrectomy within two years than those on insulin. This study provides quantitative and statistically significant evidence that diabetic patients with PDR receiving PRP have a 12.2% and 21.1% likelihood of undergoing a vitrectomy within the next one to two years, respectively. Patients who present with PDR with other clinical findings, such as VH, fibrosis, traction, and both VH and traction together, will have a much higher likelihood of requiring a vitrectomy within the next couple of years.

Reference

Ocular findings at initial pan retinal photocoagulation for proliferative diabetic retinopathy predict the need for future pars plana vitrectomy.
Parikh R, Shah R, Vanhouten J, et al.
RETINA
2014;34(10):1997-2002.

RETINA

Timing of vitrectomy for retained lens fragments
Reviewed by: Saruban Pasu
Vol 21 No 5
 

The purpose of this study was to compare the results of same setting vitrectomy with delayed vitrectomy for retained lens fragments following cataract surgery. Same setting vitrectomy was defined as the patient not leaving the operating table following cataract surgery. Significantly delayed surgery was defined as vitrectomy occurring more than 28 days after phacoemulsification. The authors retrospectively looked at 28 eyes (13 same setting, 15 delayed setting). Pre-cataract extraction, there were no significant differences in axial length, IOP, or median BCVA between the two groups. The mean time from cataract extraction to vitrectomy was 26.6 days in the delayed group. More eyes in the delayed group had IOL insertion at the time of cataract surgery, before vitrectomy. There were no differences between the groups in change of BCVA from initial pre-cataract visit to the most recent examination. Although not significant, there was a trend for same setting eyes to achieve good vision faster. More eyes in the delayed group had an IOP greater than 30mmHg at some time point during the postoperative course. Seven eyes were in the significantly delayed group, all of whom showed no significant difference from the same setting group regarding any follow-up outcomes. The authors conclude that although same setting surgery offers no significant acuity advantage over delayed surgery, in patients with advanced glaucoma where an IOP of more than 30 would not be desirable, same setting surgery may be advantageous.

Reference

A comparison of same setting versus delayed vitrectomy in the management of retained lens fragments after cataract surgery.
Orlin A, Parlitsis G, Chiu Y, et al.
RETINA
2014;34:1969-76.

STRABISMUS

Strabismus and binocular summation
Reviewed by: Fiona Rowe
Vol 21 No 5
 

The authors conducted a pilot study to investigate the effect of visual noise or background complexity on binocular summation in patients with strabismus. A target embedded in pixel noise was used. The study involved performance of a task detecting a luminance target measured at 0, 10 and 20udeg2 of visual noise for binocular and monocular conditions. Subjects included 10 with exotropia, 10 with esotropia and 13 controls. Overall, for esotropia and exotropia, a significant decrease in binocular summation was noted compared to controls. For exotropia alone, there was also a significant lower amount of binocular summation. Mean binocular inhibition (summation ratio <1) was at both noise levels. The authors conclude that strabismus can lead to decreased binocular summation and binocular inhibition.

Reference

Effects of visual noise on binocular summation in patients with strabismus without amblyopia.
Pineles SL, Lee PJ, Velez F, Demer J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:100-4.

STRABISMUS

VDT use and dry eye disease in children
Reviewed by: Fiona Rowe
Vol 21 No 5
 

There has been an increase in the amount of work performed using video display terminals. This study compared school children with and without dry eye disease and evaluated the risk factors of dry eye disease and evaluated the risk factors of dry eye disease associated with video display terminal (VDT) use. Three-hundred-and-two children were included: 14 with nocturnal lagophthalmos, trichiasis or epiblepharon were excluded. Twenty-eight children had dry eye disease – mean age of 11 years ±0.61. Two-hundred-and-sixty children served as controls – mean age of 10.87 years ±0.66. Fifty-one percent used smartphones and all used computers and TVs. The results showed that use of phones, duration of phone use and duration of VDT use increased risk of symptoms. Complaints included visual fatigue, dryness, headaches and burning sensations. The dry eye group had punctuate epithelial erosions. Phone use in the dry eye group was 71% versus 50% in the control group.

Reference

Association between video display terminal use and dry eye disease in school children.
Moon JH, Lee MY, Moon NJ.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:87-92.

ACTA OPHTHALMOLOGICA

Long-term open angle glaucoma cohort study
Reviewed by: Nana Theodorou
Vol 21 No 4
 

This was a study to estimate the development of open angle glaucoma (OAG) in a screened and re-examined elderly group as compared to an unscreened group during the same time period. The participants comprised of 856 individuals born in 1915 and living in the municipality of Skellefteå in 1981. A randomly selected subgroup of the cohort (40%) was repeatedly screened every seventh year for 21 years with regular eye examination at the same hospital. Suspected OAG cases were followed until 2002 for the development of OAG. Medical records were collected and analysed for OAG to included visual fields, optic nerve head description and IOP measurement. The numbers of OAG cases were compared between the screened group and the unscreened group. The cohort consisted of 339 screened and 517 unscreened participants with a higher incidence of diagnosed OAG in women in the screened group. Before 1981, there were six cases of OAG in the screened group and nine cases in the unscreened group. During the follow-up period from 1981 to 2002, there were 33 new cases in the screened group and 31 new cases of OAG in the unscreened group. There was no significant difference between the two groups but only a tendency for higher proportion of diagnosis in the screened group possibly due to the small sample size.

Reference

Diagnosed open-angle glaucoma in screened versus unscreened subjects – a long-term age cohort study.
Astrom S, Stenlund H, Linden C.
ACTA OPHTHALMOLOGICA
2014;92:501-6.

ACTA OPHTHALMOLOGICA

Long-term outcomes for hereditary retinoblastoma
Reviewed by: Nana Theodorou
Vol 21 No 4
 

Earlier diagnosis and more rigorous treatment regimens have contributed to better outcomes for patients with retinoblastoma. This study looked at 24 patients with hereditary bilateral retinoblastoma treated with systemic chemotherapy during a ten year period (2001-2011). The medical notes were reviewed for demographic data, presenting clinical signs, heredity and treatment. Chemotherapy treatment consisted of four to six cycles of vincristine, etoposide and carboplatin (VEC), administered to all newly diagnosed patients with bilateral disease. The authors detail treatment regimens in detail for the interested reader and correlate the stage of the disease with the treatment received. The majority of patients (83%) responded to the treatment and all patients completed their chemotherapy. Altogether 26% (12 of 46) of the eyes received second-line therapy with a failure rate of 35% and mortality rate 0%. The mean follow-up was 60 months. The demographic data for all patients is nicely presented in a comprehensive table to include age, gender, age at diagnosis and stage of the disease. The results indicated that group A/B retinoblastomas have a distinct chemotherapy response, while group C/D/E tumours do not respond as well. The success rate was 65%; while patients have a good prognosis for life, approximately one-third of all hereditary cases received radiation therapy or underwent enucleation.

Reference

A 10-year experience of outcome in chemotherapy-treated hereditary retinoblastoma.
Bartuma K, Pal N, Kosek S A, et al.
ACTA OPHTHALMOLOGICA
2014;92:404-11.

ACTA OPHTHALMOLOGICA

Nystagmus and associated diagnosis
Reviewed by: Nana Theodorou
Vol 21 No 4
 

Patients with nystagmus attending a Low Vision clinic in Sweden were included in this study. Medical records were reviewed to exclude those with general diagnoses that could explain the nystagmus. The remaining group of patients underwent subjective refraction, retinoscopy, ocular motility, colour vision, ophthalmic examination and optical coherence tomography. Electroretinogram and genetic analyses were performed in some patients as indicated. The authors identified 62 patients with nystagmus as their main diagnosis with 43 of them having a major diagnosis other than nystagmus. Nystagmus was the major diagnosis in 19 patients, 15 of whom, aged 6-76 years, participated in the study. Two of the patients had foveal hypoplasia and albinism, four a seemingly isolated foveal hypoplasia, three achromatopsia, one rod-cone dystrophy, one degenerative high myopia, and two could not be evaluated. Only two patients appeared to have ‘congenital’ nystagmus. Eleven of the patients underwent a comprehensive genetic investigation of the PAX 6 gene. In addition, four of the patients were analysed for mutations in FOXC1 and PITX2 and one in FRMD7. No mutations were found in any of the patients analysed. The study illustrates that many patients in this select study group with nystagmus had associated underlying ophthalmic diagnoses. The authors conclude that early diagnosis is important to facilitate patient rehabilitation and provide appropriate family counselling.

Reference

‘Congenital’ nystagmus may hide various ophthalmic diagnoses.
Holmstrom G, Bondeson ML, Eriksson U, et al.
ACTA OPHTHALMOLOGICA
2014;92:412-6.

ACTA OPHTHALMOLOGICA

Retinal blood flow changes in glaucoma
Reviewed by: Nana Theodorou
Vol 21 No 4
 

This study examined the changes in retinal blood flow and vessel diameter after IOP reduction in high- and low-pressure glaucoma; exfoliation glaucoma (ExG) and normal-tension glaucoma (NTG). Glaucoma progression is seen at times in eyes despite IOP reduction and changes in blood flow have been previously detected in the ocular vasculature. The study recruited consecutive patients attending for deep sclerectomy; 17 eyes with ExG and 20 with NTG. Blood flow in the temporal peripapillary retina was measured with scanning laser Doppler flowmetry, and retinal vessel diameters were evaluated using the retinal vessel analyser. Investigations were carried out just before and three months after the operation and presented to include systemic flow, diastolic flow, mean flow and pulsation index in the temporal peripapillary retina. The results indicated that there were no differences between age, visual fields and number of topical medication. Preoperative IOP was significantly higher in ExG than in NTG (median 26 mmHg). Surgery reduced IOP significantly both in ExG eyes. After the operation, systolic retinal flow was significantly reduced in ExG eyes, whereas in NTG, HRF parameters remained unchanged. Preoperatively, the central retinal artery equivalent and arteriovenous ratio were higher in ExG than in NTG eyes. After IOP reduction, both were reduced in ExG eyes, but remained unchanged in NTG. The study concluded that there are local changes in blood flow related to IOP. Prior to IOP reduction, arterial diameter was larger in ExG eyes than in NTG eyes and this resulted in vasoconstriction and reduction of flow in ExG, whereas in NTG, both vessel diameter and retinal flow remained unchanged.

Reference

Change in retinal blood flow and retinal arterial diameter after intraocular pressure reduction in glaucomatous eyes.
Kurvinen L, Kyto J, Summanen P, et al.
ACTA OPHTHALMOLOGICA
2014;92:507-12.

AMERICAN JOURNAL OF OPHTHALMOLOGY

Comparison of two interferon gamma release assays (IGRA) for tuberculous uveitis
Reviewed by: Efrosini Papagiannuli
Vol 21 No 4
 

In this prospective cohort study the authors compared QuantiFERON-TB Gold In-Tube and T-SPOT.TB to evaluate their diagnostic accuracy. They enrolled 120 consecutive new uveitis presentations over a two year period in a tertiary centre. The majority were Chinese (61.3%), followed by Indian (20.8%) and Malay (6.6%). In total, 106/120 patients completed the follow-up for at least one year after completion of ocular and systemic treatment (including TB treatment where necessary); 43.4% presented with bilateral uveitis, 59.9% anterior, 2.6% intermediate and 15.1% posterior uveitis. 22.4% had panuveitis. The clinical signs suggesting possible underlying TB ranged from granulomatous inflammation in 25%, extensive posterior synechiae in 19.1%, vasculitis in 12.5% to serpiginous choroiditis in 0.7% (one patient). One patient had mycobacterium positive sputum sample and another patient had a positive urine sample (with a positive skin test and negative IGRA). All patients underwent ocular and systemic examination, baseline blood tests, CXR, Mantoux test, QuantiFERON-TB Gold In-Tube and T-SPOT.TB testing. The main outcome measures were the sensitivity and specificity of each test and their accuracy. The authors performed a meta-analysis of previously published literature on the prevalence of tuberculous uveitis (1987-2008) and found that recorded prevalences ranged from 0.06% (USA) to 10.5% (Saudi Arabia). The Bayesian analysis which was used for evaluation of the tests suggested that, regardless of the endemic prevalence of TB related uveitis, the QuantiFERON-TB Gold In-Tube was more specific but a little less sensitive than T-SPOT.TB and significantly more accurate in identifying tuberculous uveitis. The QuantiFERON-TB Gold In-Tube remained the more superior test after sensitivity analyses and varying the prevalence or probability of tuberculous uveitis. The authors conclude that in the absence of a gold standard test, a combination of any two IGRAs or traditional tests (skin testing), would improve the diagnostic accuracy. However, because of the high cost they recognise that further studies are needed to assess the most cost-effective combination and sequence of tests to assist in the diagnosis of tuberculous uveitis.

Reference

Prospective head-to-head study comparing 2 commercial interferon gamma release assays for the diagnosis of tuberculous uveitis.
Ang M, Wong WL, Kiew SY, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2014;157:1306-14.

AMERICAN JOURNAL OF OPHTHALMOLOGY

Outcomes of cataract surgery in patients with uveitis
Reviewed by: Efrosini Papagiannuli
Vol 21 No 4
 

This is a systematic, evidence-based literature review and meta-analysis, looking at the visual outcomes (vision 20/40 or better) of cataract surgery in uveitic eyes. The authors searched MEDLINE, EMBASE, CINHAL and CENTRAL, including English language and human studies only. They excluded conference abstracts, unpublished data, very small case-series, and studies reporting on combined procedures and intra-capsular cataracts extraction. Eighty-nine articles met the eligibility criteria out of 2815 articles. The authors standardised the results by determining the ratio of uveitic eyes in each study that achieved vision 20/40 or better after cataract surgery (95% confidence intervals). They found that 71% of eyes with quiet / mostly quiet uveitis of more than two months, at the time of surgery with intraocular lens implant (IOL), achieved the desired visual outcome of 20/40 or better postoperatively, versus 52% that were left aphakic. This was the case in 68% after phacoemulsification, 72% after extracapsular cataract extraction and 40% after pars plana lensectomy. Eyes with acrylic IOL or heparin-surface modified (HSM) polymethylmethacrylate had better outcomes (72%) than eyes with silicone IOLs (30%) or non-HSM polymethylmethacrylate (62%).The best visual outcome was achieved by patients with Fuchs heterochromic uveitis (92%), versus uveitis due to JIA (65%), intermediate uveitis (69%) or Behcet’s disease (36%). Studies regarding rarer uveitides like posterior uveitis, Vogt-Koyanagi-Harada syndrome (VKH), sarcoidosis and sympathetic ophthalmia were scarce and overall did worse with vision 20/40 or better achieved only in 40-49%. The authors highlight the limitations of their review, such as publication bias, the difficulty to adjust for various confounding attributes simultaneously (to account for prognostic characteristics), their use of a visual acuity metric, which evaluated the chance of gaining a visual acuity outcome rather than a frank visual improvement and the variability of the reported time-points, which overall were short-term. They conclude that more research is required to provide better evidence on which surgeons can confidently base their management of uveitic cataracts, with an emphasis on the individual clinical entities.

Reference

Outcomes of cataract surgery in patients with uveitis: a systematic review and meta-analysis.
Mehta S, Linton MM, Kempen J.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2014;158:676-92.

BRITISH JOURNAL OF OPHTHALMOLOGY

An educational intervention to improve adherence to high-dosage patching regimen for amblyopia
Reviewed by: Jonathan Chan
Vol 21 No 4
 

This is a randomised trial of patients recruited between the periods of March 2006 and March 2008 from ophthalmology clinics in the Leicestershire area. A total of 62 children with newly diagnosed amblyopia were allocated randomly into two treatment arms with and without educational / motivational intervention material. The material they used included story books for children, information booklets for parents, a quotation booklet from parents and children, a passport arriving at each hospital visit, decorated patches, charts with stickers for each patching period of three weeks, a video with information about amblyopia and a special session with an orthoptist after three weeks of patching treatment. Both the treatment arms were given patching treatment of 10-hours per day, six days per week for a fixed period of 12-weeks’ duration. The intervention arm received an educational / motivational intervention as above before patching. The control arm received the usual clinical information as routine. The primary outcome measures were the adherence measured using electronic occlusion dose and monitors where a success / failure binary outcome was used to account for participants who dropped out of the study defined as patching >4 h/day. The secondary outcome is the visual outcome expressed as a percentage of visual deficit. It was reported by the authors that the intervention arm had increased the adherence success rates from 45.2% in the controlled group to 80.6% in the intervention group (p=0.0027). There was no significant difference between the two groups for the visual outcome (p=0.19). The authors concluded that the intense educational / motivational intervention can improve adherence to patching to high prescribed doses, but without any significant improvement of the visual outcome observed in this study. They recommended a larger multicentre trial to confirm these findings.

Reference

An educational intervention to improve adherence to high-dosage patching regimen for amblyopia: a randomised controlled trial.
Pradeep A, Proudlock FA, Awan M, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:865-70.

BRITISH JOURNAL OF OPHTHALMOLOGY

Cataract surgery in small adult eyes
Reviewed by: Jonathan Chan
Vol 21 No 4
 

This is a retrospective audit of a five year study period, between the periods of January 2006 to December 2010, where a surgical log book search was performed. The inclusion criteria of this study were intraocular lenses (IOL) power greater than 30 D for anterior chamber fixated IOLs and greater than 35 D for posterior chamber-fixated IOLs. The other inclusion criteria for this study is a secondary intraocular lens implantation procedure and patients who had been left aphakic following primary operation to identify microphthalmic eyes that may not have received an intraocular lens implant at the same time as the cataract surgery. Exclusion criteria included an axial length greater than 20.9mm, previous intraocular surgery and other intraoperative surgical procedures apart from cataract surgery, and previous history of uveitis and surgeon in training. Forty-seven eyes fulfilled the criteria and were treated in two locations which include the Moorfields Eye Hospital and the Moorfields St Ann’s Cataract Centre. No serious intraoperative adverse events were recorded apart from the one case of iris prolapse with iris trauma, one case of endothelial corneal touch, one case of retinal detachment, two cases of postoperative inflammation and one case of chronic cystoid macular oedema. Postoperative corrective distance visual acuity was logMAR 0.3 or better in 24 eyes (62%) and only three eyes obtained worse vision. The overall ocular comorbidity rate was 53%. Ten microphthalmic eyes (26%) presented with associated congenital or hereditary pathology, and had worse visual outcomes (p<0.0001). Associated ocular diseases include: 51% study eyes include 10 eyes with congenital or hereditary pathology – one case of Leber congenital amaurosis, two cases of ocular cutaneous albinism, one case of retinal coloboma, one case of congenital cataract, three cases of retinitis pigmentosa and one case of corneal dystrophy. Acquired associated pathology include: six eyes with chronic angle closure glaucoma, two cases of pseudoexfoliation syndrome, one case of diabetic maculopathy and one case of Fuchs dystrophy. The authors conclude that microphthalmic eyes having high intraocular lens power are rare, and their presence is often associated with other ocular congenital or acquired conditions, as noted above. The authors conclude that the overall clinical outcomes were satisfactory and the surgical procedure affected by a low complication rate, as noted above.

Reference

Cataract surgery in small adult eyes.
Carifi G, Safa F, Aiello F, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98(9):1261-5.

BRITISH JOURNAL OF OPHTHALMOLOGY

Injection frequency and anatomic outcomes following conversion to Aflibercept in neovascular AMD patients
Reviewed by: Jonathan Chan
Vol 21 No 4
 

This is a retrospective study of patients with neovascular age-related macular degeneration (AMD) treated with intravitreal Lucentis and / or Avastin who were switched to aflibercept (Eylea). This study was carried out by the Casey Eye Institute retinal clinics, between May and September 2012. The inclusion criteria for the subjects are: [1] they had received at least 12 months of prior anti-VEGF therapy with either Avastin or Lucentis (for cases that had received one year anti-VEGF therapy prior to conversion with a ‘base-line study visit’ defined as the visit nearest to 12 months prior to conversion and an allowable range of 10-14 months prior to conversion); [2] visual acuity at conversion was ≥20/400 when switching to Eylea; [3] they completed 12 months (final ‘study visit’ defined as the visit nearest to 12 months following conversion and an allowable range 10-14 months) of Eylea injections without switching therapies. The outcomes in this study included:
1) The primary outcome was the mean number of injections in the year following the conversion to Eylea.
2) Secondary outcome include a change in the central macular thickness at six months and one year, presence of intraretinal (IRF) and subretinal fluid (SRF) at six months and a visual acuity at one year.
One hundred and nine patients were included in this study and the overall frequency of Eylea injections was unchanged with patients receiving 7.4 anti-VEGF injections a year prior to conversion compared with 7.2 Eylea injections in the year following (p=0.47). The change to Eylea was associated with improvement in central macular thickness from 324 to 295µ (p=0.0001 at six months) and 299µ (p=0.0047 at one year). There was no effect on the visual acuity at one year. In a particular sub-group analysis, patients who had received ≥10 anti-VEGF injections in the year prior had fewer injections (11.1 to 8.4, p=0.0001) and clinic visits (13.9 to 9.6, p<0.0001), as well as significant decrease in central macular thickness (CMT) (-35µ, p=0.02). The authors conclude that from the study group, switching to Eylea was not associated with any change in injection frequency or any improvement of the visual acuity. However, there is associated improvement in the CMT at six months and one year. For those sub-group analysis patients who have received at least 10 anti-VEGF injections in the year prior, transitioning to Eylea was associated with a reduction in injection frequency and also CMT, therefore suggesting that there is a potential cost saving in this particular sub-group of population of patients. The authors suggest that longer term research is needed with a prospective randomised trial with strict retreatment guidelines, and a monotherapy control would ideally answer some of the questions raised in this study.

Reference

Injection frequency and anatomic outcomes 1 year following conversion to Aflibercept in patients with neovascular age-related macular degeneration.
Messenger WB, Campbell JP, Faridi A, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98(9):1205-7.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Effect of phacoemulsification on trabeculectomy function
Reviewed by: Anjali Gupta
Vol 21 No 4
 

Previous studies have reported cataract surgery post trabeculectomy to be detrimental to IOP control. Conversely, other studies have reported phacoemulsification performed before trabeculectomy as a factor for bleb failure. The objective of this retrospective case control study was to evaluate the effect of phacoemulsification performed before or after trabeculectomy on IOP control. Forty-eight patients with primary open angle glaucoma (POAG) or primary angle closure glaucoma (PACG) were followed up for two years after trabeculectomy surgery. Eighteen patients had phacoemulsification subsequent to trabeculectomy (trab_phaco), and 30 patients were pseudophakic for greater than six months preceding trabeculectomy (phaco_trab). The primary outcome measures were target IOPs of A, ≤12mmHg; B, ≤15mmHg; C≤18mmHg with (qualified success) or without (unqualified success) additional topical treatment. Bleb failure was defined as the clinical need for additional topical antiglaucoma medication or further surgical intervention to achieve adequate IOP control. Bleb massage, suture removal or lysis, and postoperative 5-FU injections performed in clinics were permitted without constituting qualified success or failure. Results showed no significant difference in achieving the qualified and unqualified target IOPs in all groups A to C. In the first 12 months, significantly more trabeculectomies failed in the trab_phaco group (39%) compared with the phaco_trab group (10%). However, although this trend continued, failure rates between the two groups were not significant at 24 months.

Reference

Effect of phacoemulsification on trabeculectomy function.
Nguyen DQ, Niyadurupola N, Tapp RJ, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:433-9.

CORNEA

Accelerated (9mW/cm2) corneal collagen cross-linking for keratoconus
Reviewed by: Sharmina Khan
Vol 21 No 4
 

This is one of many studies published / to be published on corneal collagen cross-linking that has a treatment time of 10 minutes compared to the previous Dresden protocol of 30 minutes to halt progression of keratoconus. Much has changed since the original Dresden protocol including the accelerated treatment protocol. Ex-vivo porcine and in-vivo confocal studies have shown that equivalent biomechanical changes in porcine corneas are achieved in the accelerated treatment protocol. The retrospective study had inclusion criteria very different to  National Institute of Health & Care Excellence (NICE) guidance in the UK, e.g. patients with subjective deterioration in vision. Only cases with mild-moderate (grade I-II Amsler-Krumeich classification) were included. Progression was defined as a decrease in visual acuity of at least one line (logMAR), increase in corneal steepness of one dioptre (steepest keratometry) over previous six months and >1D change in prescription of glasses / contact lenses over preceding two years. Sixteen eyes of 14 patients (three females, 11 males). No statistically significant difference was found in the mean corrected distance visual acuity (CDVA), mean refractive cylinder, mean manifest refraction spherical equivalent (SE), at six or 12 months post treatment. Corneal parameters K steep, K flat, corneal astigmatism, K mean and K maximum at the corneal apex were stable at six and 12 months in all patients. No complications were observed in the follow-up period. The study did not look at endothelial cell loss at these higher energy levels. No patient developed corneal decompensation or cataract formation. These results are encouraging and in keeping with other accelerated treatment reports at 12 months, however, a longer follow-up period is required.

Reference

Accelerated (9mW/cm2) corneal collagen cross-linking for keratoconus – a 1 year follow-up.
Elbaz U, Shen C, Lichtinger A, et al.
CORNEA
2014;33:769-73.

CORNEA

Squamous metaplasia of conjunctival epithelial cells with soft contact lens wear versus non-lens wearers
Reviewed by: Sharmina Khan
Vol 21 No 4
 

Conjunctiva is composed of non-squamous epithelial cells interspersed with goblet cells, which is a secretory epithelium. Squamous metaplasia is a transformation to non-secretory epithelium, ‘keratinised’ and enlargement of the conjunctival non-goblet cells and relatively shrunken nuclei are seen on impression cytology. These changes have been reported in soft contact lens wearers. This pilot study of impression cytology taken from interpalpebral conjunctiva of 23 white female soft contact lens wearers versus 23 age matched healthy white female optometry students. The aim of the study was to further define bulbar conjunctival cell morphology in squamous metaplasia in long-term contact lens wearers in an age-matched population. All contact lens wearers showed substantial cell changes compared with controls. The results indicate in concordance with other studies that squamous metaplasia can continue to develop or persist after an average of six years of successful contact lens wear. Comparison with other reports can be confusing due to the use of different grading scales. The authors report that nuclear pyknosis (shrinking of nuclear size) does not occur, rather there is enlargement of the nucleus along with the cell size. Such cellular changes don’t always correlate with “notable fluorescein staining of exposed bulbar conjunctiva.” This interesting report doesn’t correlate findings to clinical presentation to a hospital eye service with ocular surface discomfort associated with contact lens wear. Most of the subjects recruited reported mild occasional ocular surface discomfort associated with contact lens wear.

Reference

Objective assessment of squamous metaplasia of conjunctival epithelial cells as associated with soft contact lens wear versus non-lens wearers.
Doughty MJ.
CORNEA
2014;10:1095-102.

CURRENT EYE RESEARCH

Comparison of ganglion cell thinning in glaucoma vs. macular hole repair
Reviewed by: Khadijah Basheer
Vol 21 No 4
 

This prospective study compared the changes in the photopic negative response of the focal macular electroretinogram (fmERG) caused by retinal ganglion cell complex (GCC) thinning at the macula between patients with open angle glaucoma (OAG) and 12 months after successful macular hole repair surgery (MH). It has been shown that optical coherence tomography can determine the thickness of the GCC layer and that it can be used in diagnosing and monitoring progression in glaucoma patients. In addition, GCC thinning has been correlated to the functional loss of vision determined by visual field testing in glaucoma patients. In patients who have undergone successful macular hole repair surgery a dissociated optic nerve fibre layer appearance has been noted to occur. Thinning of the GCC layer has also been demonstrated in these patients, however, any functional visual correlation to this postoperative thinning remains controversial. In this study there was significant thinning of the GCC layer in both the OAG group and MH group compared to healthy controls. However, whilst the OAG group showed a significant reduction in fmERG response, there was no significant reduction in fmERG in the MH group compared to the control group. The results show that although the GCC layer is thinned in the MH the function of GCCs remains preserved. However, in the study limitations they postulate whether longer follow-up of these patients may then reflect a possible reduction in GCC function. The study shows an interesting finding of preservation of macular function demonstrated by fmERG in patients who have undergone macular hole repair surgery, where the GCC layer is thinner than control subjects in contrast to patients with early glaucoma who have similar GCC thinning but demonstrate functional loss through fmERG. However, it remains unclear as to why this difference occurs and further study is needed before any final conclusions can be made.

Reference

Differences in functional loss associated with ganglion cell complex thinning between patients with glaucoma and postoperative macular hole.
Machida S, Tamada K, Ohzeki T, et al.
CURRENT EYE RESEARCH
2014;39(8):845-52.

CURRENT EYE RESEARCH

Meibomian gland dropout in patients with dry eyes
Reviewed by: Khadijah Basheer
Vol 21 No 4
 

In this prospective study 264 patients with symptoms of dry eye were examined with a non-contact meibography system to assess the morphological changes in their meibomian glands. These patients were not previously diagnosed with meibomian gland dysfunction and patients with active or previous ocular surface disease other than dry eye were excluded. The meibography system was composed of a slit-lamp with an infrared transmitting filter and video camera. The eyelids of patients were everted and the meibomian glands observed. Partial or complete loss of meibomian glands was scored from 0 (no loss of glands) to three (loss of area greater than two thirds). They were able to demonstrate a variety of morphological changes including shortened, tortuous, expanded and lost meibomian glands. They found a negative correlation between the meibomian gland score and Schirmers testing and tear film break up time and a positive correlation with fluorescein staining of the cornea. These results suggest that although meibomian gland dysfunction may not be clinically apparent there are morphological changes in patients with dry eyes and these patients should be counselled on how to treat meibomian gland dysfunction to improve their symptoms of dry eye. However, this study did not compare their findings to any control group and therefore we do not know how much variance there may be in meibomian gland morphology in the general population.

Reference

Meibomian gland dropout in patients with dry eyes.
Feng Y, Gao Z, Feng K, et al.
CURRENT EYE RESEARCH
2014;39(10)965-72.

CURRENT EYE RESEARCH

Short-term effects of intravitreal bevacizumab on the cornea
Reviewed by: Khadijah Basheer
Vol 21 No 4
 

Bevacizumab has been extensively used to treat macula oedema and neovascularisation of the retina and it has also been useful in the management of corneal neovascular diseases. This prospective study aimed to provide more information on the effect bevacizumab may have on the cornea as there is little known about potential corneal toxicity compared to the retina. A higher dose of bevacizumab, 2.5mg/0.1ml was injected intravitreally into 43 eyes. The subjects and a control group were studied for one month and the following measurements were taken: central corneal thickness, intraocular pressure, simulated keratometry, anterior chamber depth and iridocorneal angle. No side-effects or corneal endothelial toxicity was observed and after one month there was no statistical difference in any of the above measurements. The authors conclude from this short study that a one off dose of intravitreal bevacizumab has no toxic effects on the cornea. However, the follow-up period was only one month, we do not know whether any later effects become apparent after one month, what occurs after multiple injections of bevacizumab or the effects of injecting bevacizumab into the cornea itself. More research into this area is needed to provide further confidence regarding the safety of bevacizumab on the cornea and anterior chamber structures.

Reference

Short term effects of intravitreal bevacizumab on the cornea.
Guler M, Capkin M, Simsek A, et al.
CURRENT EYE RESEARCH
2014;39(10):989-93.

EXPERIMENTAL EYE RESEARCH

A mouse model for uveal melanoma
Reviewed by: Graham Wallace
Vol 21 No 4
 

Uveal melanoma (UM) is the most common malignant tumour arising within the eye and is a severe threat for both sight and life, due to a high risk of metastasis. There are no animal models of UM, but the Tg(Grm1) in which the glutamate receptor 1 (Grm1) transgene is under the control of the melanocyte specific dopachrome tautomerase (Dct) promoter, was developed as a model for skin melanoma. As Dct is expressed in all melanocytes the authors assessed the Tg (Grm1) mouse for signs of ocular melanoma. The results showed choroidal thickening, and uveal melanocyte neoplasia using melanocytic markers S100B and MelanA. Importantly, analysis of human UM samples showed expression of Grm1, suggesting that glutamate signalling is involved in human disease. These results identify the Tg(Grm1) mouse as a new model for uveal melanoma that should allow for further dissection of the mechanisms involved in imitation and a therapeutic model for drug testing.

Reference

Tg(Grm1) transgenic mice: a murine model that mimics spontaneous uveal melanoma in humans?
Schiffner S, Braunger BM, de Jel MM, et al.
EXPERIMENTAL EYE RESEARCH
2014;127:59-68.

EXPERIMENTAL EYE RESEARCH

Ovarian hormones drive onset of Sjogren’s disease in mice
Reviewed by: Graham Wallace
Vol 21 No 4
 

Sjogren’s syndrome (SS) is a debilitating, sight-threatening, systemic autoimmune disease with no effective treatment available. SS is characterised by lacrimal gland lymphocytic infiltration and epithelial cell death, as well as by the presence of serum autoantibodies. Patients have severe dry eyes and are at high-risk of developing corneal perforation and blindness. To investigate the onset of SS in mouse models previous studies have reported that removal of the ovaries accelerated disease in susceptible mice, with lymphocytic infiltration preceding goblet cell apoptosis. In this paper cytokine levels in ovarectomised mice were studied. The results show that levels of proinflammtory cytokines interleukin-1β, tumour necrosis factor-α and IL-4 were elevated early after surgery which anti-inflammatory IL-10 was only raised at later time points. These changes were not seen in resistant mouse strains following ovarectomy. Likewise increased levels of anti-Ro/SSA were seen in susceptible strains only. Physiological doses of E2 or dihyrotestosterone (DHT) at time of OVX prevented the upregulation of cytokines and the presence of autoantibodies in these animals. These data show a strong link between ovarian hormones and onset of SS in mice of the appropriate genetic background. Genome-wide association studies have identified several genes to be linked to SS including some involved in the immune response. Coupled with the female predisposing to this condition this paper identifies novel pathways involved in the onset of SS that should be explored

Reference

Time course of cytokine upregulation in the lacrimal gland and presence of autoantibodies in a predisposed mouse model of Sjogren’s syndrome: The influence of sex hormones and genetic background.
Czerwinski S, Mostafa S, Rowan VS, Azzarolo AM.
EXPERIMENTAL EYE RESEARCH
2014;128:15-22.

EXPERIMENTAL EYE RESEARCH

RPE use similar pathway to regulatory T cells to inhibit immune response
Reviewed by: Graham Wallace
Vol 21 No 4
 

Retinal pigment epithelial (RPE) cells form an important part of the blood-retinal barrier that protects the neuronal cells responsible for sight. RPE cells are involved in innate and adaptive immune responses via expression of surface molecules and release of cytokines. However, RPE cells under normal conditions are anti-inflammatory, a function linked to expression of molecules such as FasL and the release of immunosuppressive molecules. In this paper the authors show that CD73, a GPI-anchored nucleotidase expressed on RPE cells abrogated immune responses in the animal model experimental autoimmune uveoretinitis. Proinflammatory adenosine triphosphate (ATP) is released during inflammation and is converted to adenosine monophosphate (AMP) by CD39 and to anti-inflammatory adenosine by CD73. The results show that normal mouse RPE shows strong expression of CD73, which was significantly reduced in inflamed eyes or RPE from inflamed eyes. In an in vitro chamber assay CD73-poitive RPE cells inhibited T cell activation on addition of AMP, whereas CD73-negative cells did not. CD73 has been described as a marker of regulatory T cells and this paper demonstrates that it performs a similar function in RPE cells to protect the retina from deleterious immune responses.

Reference

CD73 expression in RPE cells is associated with the suppression of conventional CD4 cell proliferation.
Chen S, Zhou S, Zang K, et al.
EXPERIMENTAL EYE RESEARCH
2014;127:26-36.

JAMA OPHTHALMOLOGY

Are single IOP measurements adequate for estimating the effect of IOP lowering interventions?
Reviewed by: Lona Jawaheer
Vol 21 No 4
 

The World Glaucoma Association recommends that, to assess the effect on intraocular pressure (IOP) of medication or surgery, the mean of multiple measurements of postoperative IOP is a better reflection of IOP than a single measurement of postoperative IOP. The authors hypothesised that a single IOP measurement might approximate the mean of several measurements. Pre-randomisation data from the COMPASS study was analysed by the authors. A total of 609 patients (609 eyes) with primary open-angle glaucoma and cataract were included. A single randomly-timed IOP measurement was made at the screening visit while the patient was still receiving their usual glaucoma medication regimen. The medications were then discontinued (for pre-specified periods of time) and, at a baseline visit following complete medication washout, IOP measurements were taken at 8am, 12pm and 4pm. The authors calculate the proportion of eyes in which the increase in IOP after washout, using the mean of the three measurements, differed by more than 0.5, 1.0, 1.5, or 2.0mmHg from the increase in IOP after washout using only one of the post washout measurements. The mean (SD) IOP before washout was 18.5 (4.0) mmHg. The mean increase in IOP after washout, using the mean of the three measurements, was 5.3 (4.2) mmHg. The percentage of eyes in which the increase in IOP using a single post washout IOP differed from the increase in IOP using the mean of three measurements by more than 1.5mmHg was 35.1%, 25.6%, 34.2%, 30.0% and 31.4% when the single measurement was made at 8am, 12pm, 4pm, a randomly chosen single measure of those three times, and the time closest to that of the prewash out IOP, respectively. As more than 10% of the eyes (previously agreed cut-off) had a difference greater than 1.5mmHg for all single measurements, compared to the mean of three IOP measurements, the authors concluded that single IOP measurements are not a reliable replacement for multiple diurnal IOP measurements for IOP lowering medication, although they might be for post-surgical interventions, as the diurnal variation post-surgery is known to be narrower.

Reference

Single vs multiple intraocular pressure measurements in glaucoma surgical trials.
Zhang ML, Chon BH, Wang J, et al.
JAMA OPHTHALMOLOGY
2014;132(8):956-62.

JAMA OPHTHALMOLOGY

Do topical steroids improve visual outcome in the treatment of bacterial keratitis?
Reviewed by: Lona Jawaheer
Vol 21 No 4
 

The use of topical corticosteroids as an adjunctive treatment to antibiotics in the management of bacterial keratitis remains a controversial issue. The results of the Steroids for Corneal Ulcers Trial (SCUT) – a randomised, double-masked, placebo-controlled trial that recruited patients at two US centres and one centre in India – were published in 2012 and showed that adding topical corticosteroids to topical moxifloxacin hydrochloride in bacterial keratitis did not appear to have a beneficial effect on best spectacle corrected visual acuity (BSCVA) at three months. The authors of this article hypothesised that the trial did not take into account the timing of the corticosteroid / placebo treatment with respect to the start of the antibiotic drops, and that the true effect of corticosteroid treatment could therefore have been masked. The improvement in BSCVA at three months was calculated in the groups that received corticosteroids / placebo early (within two to three days of starting antibiotics) or late. In the early group, use of corticosteroids was associated with a –0.11 logMAR BSCVA improvement (n=311; 95%CI, –0.20 to –0.02; P=.01) compared with placebo group. In the late group, corticosteroid treated patients had one-line worse visual acuity than did the placebo-treated patients, although this effect was not significant (n=139; 0.10 logMAR; 95%CI, –0.02 to 0.23; P=.14). The benefit of early administration of corticosteroids was maintained for mild, moderate and severe ulcers. When patients with Nocardia keratitis were excluded from the multiple linear regression model, corticosteroids were beneficial when administered earlier and neutral when administered later. Corticosteroids have been shown to adversely affect outcome in cases of fungal or Acanthamoeba keratitis. In the SCUT trial, patients with Nocardia keratitis were also adversely affected by corticosteroids. Therefore, it is important to be certain of the diagnosis prior to starting corticosteroids. These results suggest that early administration of corticosteroids in bacterial corneal ulcers might result in a better visual outcome for the patient.

Reference

Early addition of topical corticosteroids in the treatment of bacterial keratitis.
Ray KJ, Srinivasan M, Mascarenhas J, et al.
JAMA OPHTHALMOLOGY
2014;132(6):737-41.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

Amblyopia treatment review
Reviewed by: Fiona Rowe
Vol 21 No 4
 

This review paper summarises the main causes and neural mechanisms that characterise amblyopia. The authors analysed neuroanatomical, neurophysiological and electrophysiological studies in the literature to better understand actual treatment regimens and evaluate new therapeutic possibilities. They considered causes of strabismus, anisometropia and deprivation amblyopia. Treatment options included surgical correction of strabismus, cataract and ptosis, refractive correction, occlusion and penalisation, perceptual learning, transcranial magnetic stimulation and binocular treatment. Drug therapies included Carbidopa-Levodopa, phenylethylamine, citicoline and Bicuculline. These substances may be able to promote the recovery of visual function in partially sighted patients and make a more stable and long-lasting treatment.

Reference

Amblyopic treatment strategies and new drug therapies.
Pescosolido N, Stefanucci A, Buomprisco G, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:78-86.

NEURO-OPHTHALMOLOGY

A rare case of post-traumatic central retinal artery occlusion
Reviewed by: Claire Howard
Vol 21 No 4
 

Central retinal artery occlusion is rarely associated with traumatic optic neuropathy, this case report details of one such case. The reported case is of a ten-year-old boy presenting after a fall from height with loss of vision in one eye. Vision was reduced to no perception of light and a CT scan revealed fractures of the medial orbital wall and roof and a diagnosis of traumatic optic neuropathy with central retinal artery occlusion was made. Surgical intervention was performed within 24 hours with optic canal decompression through a transorbital route. Postoperatively the child’s vision returned to 6/9 within one month, which was maintained at a five year follow-up. This highlights the possibility of a local decompression of the optic nerve using a transcaruncular-transorbital approach combined with direct fibrinolysis, which in this case provided an excellent visual outcome.

Reference

Optic canal decompression and direct ophthalmic artery fibrinolysis for traumatic optic nerve neuropathy with central retinal artery occlusion.
Vaitheeswaran K, Kaur P, Garg S, Nadar M.
NEURO-OPHTHALMOLOGY
2014;38(3):127-30.

NEURO-OPHTHALMOLOGY

Choroidal and macular thickness in nonarteritic anterior ischaemic optic neuropathy
Reviewed by: Claire Howard
Vol 21 No 4
 

This study evaluates the choroidal and macular thickness in patients with chronic nonarteritic anterior ischaemic optic neuropathy (NA-AION). Two groups of subjects were compared, group one included 20 eyes with chronic NA-AION and group two, 31 healthy control eyes. The control group was demographically similar to the affected group. In both groups, choroidal and macular thickness was measured using the enhanced depth imaging program of Heidelberg Spectralis® optical coherence tomography. Macular thickness was found to be reduced in eyes that had an episode of NA-AION. Choroidal thickness was found to generally be higher in affected eyes compared to healthy controls. This increase in choroidal thickness was attributed by the authors to a local dysfunction in vascular autoregulatory mechanisms. The results show a change in choroidal thickness with chronic NA-AION. Future studies are required to test the potential of these findings for the future identification of patients at risk of this devastating eye condition, or in the follow-up of identified patients.

Reference

Choroidal thickness in nonarteritic anterior ischaemic optic neuropathy: a study with optical coherence tomography.
Dias-Santos A, Ferreira J, Abegao Pinto L, et al.
NEURO-OPHTHALMOLOGY
2014;38(4):173-80.

NEURO-OPHTHALMOLOGY

Early intraocular complications of aneurysmal subarachnoid haemorrhage
Reviewed by: Claire Howard,
Vol 21 No 4
 

The aim of this study was to estimate the incidence of a whole spectrum of early intraocular complications in patients suffering from aneurysmal subarachnoid haemorrhage (SAH) and to identify factors that are potentially associated with these fundus findings. In total the authors analysed 96 cases of aneurysmal SAH. Forty patients (42%) had abnormal fundus findings, these included disc swelling in 13.5%, retinal haemorrhages in 23% and vitreous haemorrhage in 5%. The incidence of intraocular pathologies was significantly higher in patients who lost consciousness at the onset of SAH, were admitted with high scores of the Hunt-Hess and Fisher scales and low score of the Glasgow Coma Scale, as well as in those with arterial hypertension, more sizeable aneurysm and older patients. In summary, the risk factors for intraocular complications included the severity of SAH, loss of consciousness, larger aneurysm, older age and arterial hypertension.

Reference

Early intraocular complications of subarachnoid haemorrhage after aneurysm rupture.
Obuchowska I, Turek G, Mariak Zenon, Mariak Zofia.
NEURO-OPHTHALMOLOGY
2014;38(4):199-205.

NEURO-OPHTHALMOLOGY

Effect of oxygen levels on binocular summation of dark vision
Reviewed by: Claire Howard
Vol 21 No 4
 

Previous studies have reported conflicting results on the existence of binocular enhancement of dark vision. This study compares monocular and binocular absolute thresholds of dark adaptation in two different populations (healthy individuals and those with chronic respiratory insufficiency). The study aims to answer the previously unresolved questions regarding binocular summation at absolute threshold. Study Group A consisted of 18 healthy individuals, Group B recruited 13 patients with respiratory failure. All recruits in both groups were examined by computerised dark adaptometry on three separate visit days. Group B received oxygen supplement at visits one and three, but not at visit two. In group A, binocular dark adaptation was significantly more sensitive than monocular adaptation across all three visits. In group B, at visits one and three, binocular dark adaptation was also significantly more sensitive than monocular. However, at visit two, when no oxygen supplement was given, no significant difference was found between binocular and monocular summation. This study goes some way to answering questions regarding binocular summation in reporting that a deficit in oxygen seems to affect the binocular adaptation, and that binocular summation exists at absolute threshold.

Reference

Two eyes are better than one – binocular summation of dark vision in healthy individuals and patients with chronic respiratory disease.
Thylefors J, Havelius U.
NEURO-OPHTHALMOLOGY
2014;38(3):113-21.

NEURO-OPHTHALMOLOGY

Gender and ethnicity related differences in optic nerve head
Reviewed by: Claire Howard
Vol 21 No 4
 

The authors investigated the effect of ethnicity and gender on optic nerve head morphology comparing Indian and Caucasian males and females. The optic nerve head was investigated using spectral-domain optic coherence tomography (SD-OCT). Results showed that disc and rim areas were larger in Caucasian males compared to females, but smaller in Indian males compared to females. Overall, Indian subjects had a significantly larger cup area and volume, but there was no difference in retinal nerve fibre layer between the two groups. These study findings should be considered when assessing a variety of patients in a clinical setting. Care should be taken when comparing patients’ recordings with normative data supplied with OCT machines as these often don’t include gender and ethnicity differences, making results difficult and inaccurate to interpret.

Reference

Gender and ethnicity-related differences in optic nerve head topography in healthy Indian and Caucasian participants.
Pilat AV, Gottlob I, Sheth V, et al.
NEURO-OPHTHALMOLOGY
2014;38(4):205-13.

NEURO-OPHTHALMOLOGY

Ocular blood flow changes in Behcet disease
Reviewed by: Claire Howard
Vol 21 No 4
 

This study evaluates ocular blood flow changes in both ocular Behcets disease (BD) and non-ocular BD (with or without thrombotic disease) and compares these findings with a healthy control group. A total of 90 eyes with BD were evaluated with a range of ocular involvement from no involvement to active uveitis. These affected eyes were compared with 120 matched control eyes. All eyes were measured using colour Doppler ultrasonography (CDU) assessing ophthalmic, central retinal and ciliary artery flow parameters. Results from this significant sample size showed major haemodynamic changes in the ophthalmic vessels of ocular Behcet patients. In addition, in non-ocular BD patients with thrombolysis, blood flow parameters were affected more than those without thrombolysis and healthy controls. This suggests that CDU may detect ocular blood flow alterations before ocular clinical manifestations appear in BD patients, creating opportunity for earlier interventions.

Reference

Ocular blood flow changes in Behcet disease patients with/without thrombotic disease.
Yuksel H, Turkcu FM, Hamidi C, et al.
NEURO-OPHTHALMOLOGY
2014;38(3):122-6.

NEURO-OPHTHALMOLOGY

Ocular ischaemic syndrome in a rat model
Reviewed by: Claire Howard
Vol 21 No 4
 

Ocular Ischaemic syndrome is a devastating eye disease caused by severe carotid stenosis. This study’s purpose was to develop a reliable rat model for this syndrome by subjecting rats to common carotid artery occlusion and sham surgery. Rats were assigned into one of two groups receiving different procedures, the sham surgery group and the stenosis group. For this study, the common carotid artery in the rat model was ligated unilaterally or bilaterally with needles of different diameters and the ocular arterial filling time examined by fluorescein fundus angiography at different time intervals. Bilateral common carotid artery occlusion was a more effective model than unilateral occlusion. Results showed that the arterial filling time was significantly increased at 14 and 21 days after ligation compared with preoperatively. The total blood flow in the sham surgery group was significantly higher than in the bilateral common carotid artery occlusion group. The fundus blood flow was statistically different between the two groups, whereas that of the anterior segment was not. The authors have concluded that a successful rat model of ocular ischaemic syndrome has been achieved and that this was reliable up to two to three weeks after surgery. This model could potentially be used in future research and in the investigation of new treatments.

Reference

Bilateral common carotid artery occlusion in the rat as a model of retinal ischaemia.
Huang Y, Fan S, Li J, Wang Y-L.
NEURO-OPHTHALMOLOGY
2014;38(4):180-9.

NEURO-OPHTHALMOLOGY

Reliability of kinetic perimetry in children and young adults
Reviewed by: Claire Howard
Vol 21 No 4
 

This study reports on normative visual field area, feasibility and repeatability of testing for a large sample size of healthy children and young adults, using Octopus semi-automated kinetic perimetry. Sample included 221 healthy volunteers aged 5-22 years. The study was performed following a literature search which indicated stark disagreement on the rate of peripheral visual development and age of peripheral visual maturation. If semi-automated kinetic perimetry is to be performed in a clinical setting, availability of normative data for visual fields at a given age, expected ability and reliability is essential. Octopus kinetic perimetry is fast becoming the visual field test of choice in many clinics and as such, expected feasibility and normative visual field and blind spot data are required, especially for children. Reliable visual fields were plotted in 23% of participants <10 years, 64% of 10-12-year-olds and 98% aged 13-22 years. Reaction times reduced with age. Visual fields were assessed using I4e and I2e stimuli at 5°/second or 3°/second. Visual field areas were unchanged with age using 5°/second, but increased using 3°/second for I2e. Therefore, a test speed of 5°/second is recommended for healthy children and adults. The study found that participants aged 13 years or older and approximately 2/3 aged 10-12 years can reliably perform kinetic perimetry on the octopus perimeter. Although testing is possible with younger children, the authors recommend exercising caution when interpreting the test results from children under 13 years of age.

Reference

Peripheral visual fields in children and young adults using semi-automated kinetic perimetry: feasibility of testing, normative data and repeatability.
Bjerre A, Codina C, Griffiths H.
NEURO-OPHTHALMOLOGY
2014;38(4):189-99.

NEURO-OPHTHALMOLOGY

Two case reports of late onset adbucens nerve palsy following carotid-cavernous fistula treatment
Reviewed by: Claire Howard
Vol 21 No 4
 

This report presents two cases of abducens palsy developing with late onset following endovascular treatment for carotid-cavernous fistula. Following this common and effective treatment for carotid-cavernous fistula, an immediate cranial nerve palsy is a common finding. It usually resolves spontaneously. In both these cases, total obliteration of the fistula without a residual shunt was confirmed. However, both cases went on to develop late onset abducens nerve palsy months after the procedure. Both cases went on to require strabismus surgery to treat their ocular motility disorders. The underlying mechanism is unknown and the authors suggest it may be a different mechanism to that of immediate or delayed cranial nerve palsies, due to the fact that the symptoms in these cases did not resolve.

Reference

Late-onset abducens nerve palsy after endovascular treatment for carotid-cavernous fistula: two case reports.
Liu Y-L, Hsieh Y-H, Tsai T-H.
NEURO-OPHTHALMOLOGY
2014;38(3):131-4.

OCULAR IMMUNOLOGY AND IMFLAMMATION

Choroidal thickness in ocular sarcoidosis by OCT measurement
Reviewed by: Nikolaos D Georgakarakos
Vol 21 No 4
 

This is the first study to evaluate the choroidal thickness in patients with ocular sarcoidosis during the quiescent phase using enhanced depth imaging optical coherence tomography (EDI-OCT) and comparing with normal subjects. Ocular sarcoidosis may affect the choroidal circulation (occlusive arteriolitis) which may induce the reduction of the choroidal thickness. During the inflammatory phase the thickness of the choroid may change. The study included 18 eyes of nine patients with ocular sarcoidosis (eight women and one man mean age 59 years +/-18.5) and their subfoveal choroidal thickness was measured using EDI-OCT and compared to the age, sex and spherical equivalent-matched normal subjects. The mean subfoveal choroidal thickness was 281.76+/- 88µm in patients with sarcoidosis and 432+/-71µm in controls. Significant differences were found at points between the nasal 1500µm and temporal 1000µm to the fovea between patients and control group (p=0.002 at fovea). Therefore, the patients with sarcoidosis had thinner choroidal layer in the quiescent phase when compared to control subjects.

Reference

Choroidal thickness in ocular sarcoidosis during quiescent phase using enhanced depth imaging optical coherence tomography.
Gungor SG, Akkoyum I, Reyhan NH, et al.
OCULAR IMMUNOLOGY AND IMFLAMMATION
2014;22(4):287-93.

OCULAR IMMUNOLOGY AND IMFLAMMATION

Diagnostic procedures in vitreoretinal lymphoma
Reviewed by: Nikolaos D Georgakarakos
Vol 21 No 4
 

This paper presented a retrospective review of medical records of HIV negative immunocompetent patients diagnosed with vitreoretinal lymphoma between 1994 and 2012. The aim of the paper was to evaluate the type and number of diagnostic interventions required to confirm the presence of vitreoretinal (VR) lymphoma. Twenty-seven cases were included. Of the 27 cases, diagnosis using pars plana vitrectomy was made in 13 (48%), vitreous tap in two (7.5%) and anterior chamber tap in one (3.7 %), chorioretinal biopsy in two (7.5%), brain biopsy in five (18.5%) and cerebrospinal fluid cytology via lumbar puncture in four (14.8%). Ten patients (37%) had definitive results on the first procedure and 17 (63%) had at least one false negative. Vitrectomy was the most common procedure and patients required a mean of 2.1 procedures. The average time from onset of symptoms to confirmed histopathological diagnosis was 13.9 months. VR lymphoma, a common masquerade uveitic syndrome, is difficult to recognise and requires a high degree of clinical suspicion. Most patients were initially thought to have idiopathic uveitis and treated with systemic corticosteroids. Treatment with corticosteroids at the time of vitrectomy may further complicate the diagnosis by leading to lysis of the lymphoma cells and false negative results of the vitreous samples. In this study none of the patients were on corticosteroid therapy at the time of vitreous sampling.

Reference

Diagnostic procedures in vitreoretinal lymphoma.
Dalal M, Casady M, Moriarty E, et al.
OCULAR IMMUNOLOGY AND IMFLAMMATION
2014;22(4):270-6.

OCULAR IMMUNOLOGY AND INFLAMMATION

Polymerase chain reaction evaluation of infectious multifocal serpiginoid choroiditis
Reviewed by: Nikolaos D Georgakarakos
Vol 21 No 4
 

This paper presents a retrospective review of infectious agents associated with multifocal serpiginous choroiditis (MSC) based on polymerase chain reaction (PCR) evaluation and specific antimicrobial therapy. The study included 13 patients with MSC who were evaluated with PCR for the following organisms: mycobacterium tuberculosis (MTB), herpes simplex virus 1 (HSV1), Varizella zoster virus (VZV) and cytomegalus virus (CMV). Nine (69%) were positive for one or more organisms. Seven (54%) were positive for MTB, three (23%) for CMV. Nine patients completed six months follow-up and six resolved completely. Two continued to have lesions and one CMV positive required further additional valgancyclovir treatment. In this study the authors used multitarget PCR for MPB64 gene rather than the conventionally used multicopy element IS6110 because it gives better diagnostic yield. All but one of these patients showed complete resolution of inflammation following antiTB and steroid treatment. Tuberculosis (TB) remains the commonest and most important cause for MSC and PCR (of ocular fluid samples) can be a useful diagnostic tool. However, the role of HSV still remains to be established.

Reference

Polymerase chain reaction evaluation of infectious multifocal serpiginoid choroiditis.
Mohan N, Balne PK, Panda KG, et al.
OCULAR IMMUNOLOGY AND INFLAMMATION
2014;22(5):384-90.

OPHTHALMIC PLASTIC & RECONSTRUCTIVE SURGERY

A tarso-conjunctival flap for paralytic ectropion
Reviewed by: James Hsuan
Vol 21 No 4
 

This is a review of 110 patients with paralytic ectropion who underwent a lateral tarso-conjunctival flap procedure. The technique involves fashioning a 4-8mm wide lateral tarso-conjunctival flap in a similar way to a lateral Hughes flap. This is then sutured to the de-epithelialised margin of the lateral lower lid posterior lamellar. In the 45 patients who also had significant horizontal laxity, a simultaneous lid tightening was performed with a modified lateral tarsal strip. Lagophthalmos and lid retraction improved in all cases, but unfortunately there is no data regarding the degree of improvement. Ocular surface exposure and keratopathy also improved in all patients. Complications were relatively rare and minor and patients reported high levels of satisfaction with the surgery. Interestingly there was even some improvement in lower lid movement on eye closure, which the authors suggest was due to a Bells’ phenomenon resulting in the upward movement of the superior fornix, which then exerts an additional lift on the lower lid via the flap. One drawback is potential loss of some temporal field, although this may be improved by trimming back the flap without a significant loss of effect on the lower lid position. The technique looks to have merit and has not been published previously. The authors acknowledge the limitations of a retrospective series, but the lack of long-term follow-up data is a particular drawback in patients with paralytic ectropion.

Reference

Lateral tarsoconjunctival only flap lower eyelid suspension in facial nerve paresis.
Tao JP, Vemuri S, Patel AD, et al.
OPHTHALMIC PLASTIC & RECONSTRUCTIVE SURGERY
2014;30:342-5.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Factors affecting the success of canalicular repairs
Reviewed by: James Hsuan
Vol 21 No 4
 

This is a ten year retrospective review of 137 canalicular laceration repairs, looking for factors which affected the outcome. A successful outcome was defined as no epiphora at three months or more after removal of the stent. Overall the success rate was 72%, but 86% of repairs done in an operating theatre were successful compared with 37% of those done in a minor procedures room. Level of training was also a major determinant, with a fellowship trained oculoplastic consultant achieving 84% success, oculoplastic fellows 44%, non-oculoplastic consultants 29% and residents 25%. There was no significant difference comparing monocanalicular with bicanalicular intubation, but only 17 patients had bicanalicular stenting. The vast majority of those left with epiphora found it bothersome to some degree. The authors admit that lack of epiphora is not the same as anatomical patency, and using this criterion alone probably overestimates the success of surgery. There is no analysis of outcomes comparing upper lid lacerations with lower lids, but the authors recommend all canalicular lacerations are repaired. This is the first publication to address the specific factors of level of training and location of surgery as determinants of success in canalicular repairs. The highly significant difference in success rates make a strong case for recommending that all canalicular repairs should be done by, or supervised by, an oculoplastic trained consultant in main theatres.

Reference

Canalicular laceration repair: an analysis of variables affecting success.
Murchisan AP, Bilyk JR.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2014;30:410-4.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Outcomes and complications of supramaximal levator resection
Reviewed by: James Hsuan
Vol 21 No 4
 

This is a report of 35 children with unilateral congenital ptosis who underwent a supramaximal levator resection, involving extensive dissection of levator including cutting Whitnall’s ligament. The average preoperative margin reflex distance to the upper lid (MRD1) was 0.5mm, and the average levator function was 6.6mm. Photographic analysis at least six months post-surgery showed the average MRD1 had improved to 3.4mm, and the difference in MRD1 with the fellow eye had reduced from 3.1mm to 0.1mm, with 80% of patients having 1mm or less of asymmetry. There were minor contour abnormalities in 29% and 31% had lash ptosis. Fourteen patients also underwent assessment of their blink amplitudes, both spontaneous and when looking from primary to 30 degrees of downgaze, using a magnetic search coil. Blink amplitudes were very poor on the first postoperative day, requiring intense lubrication and Frost sutures for the first week. They remained reduced at a mean of 37 months post-surgery, when the average spontaneous blink amplitude was 37%, and the downward saccadic movement 55%, of the fellow eye amplitudes. The discussion describes how our understanding of Whitnall’s ligament has evolved, with reasons to question the traditional view of it as either a significant supporting structure or a fulcrum to change the direction of pull of the levator muscle. These previously held concepts have been reasons to avoid supramaximal surgery which requires cutting Whitnall’s. The authors admit the procedure remains contentious, but also explain that the alternatives are limited. Unilateral brow suspension in the absence of compensatory ipsilateral frontalis overaction is often unsatisfactory, and parents usually refuse bilateral surgery. The technique lifts the lid well, but has the drawback of exposure from reduced blink amplitudes and should not be used if there is a poor Bell’s reflex. Contour defects and lash ptosis also occur, but the latter can be reduced by careful re-fixation of the tarsal skin muscle flap to levator. Due to its retrospective nature some data which would have been interesting is not provided, such as the preoperative blink amplitude to see how much this had been affected by the supramaximal resection.

Reference

Supramaximal levator resection for unilateral congenital ptosis: cosmetic and functional results.
Cruz AAV, Akaishi PMS, Mendonca AKTS, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2014;30:366-71.

OPHTHALMIC RESEARCH

Effect of voriconazole of vision of healthy volunteers
Reviewed by: Bheemanagouda Patil
Vol 21 No 4
 

Voriconazole is a broad spectrum, triazole antifungal agent used for systemic fungal infections. It has a favourable safety profile and is available in both intravenous and oral forms. The commonest adverse drug reactions with voriconazole are changes in visual perception, namely, increased visual perception (object appearing brighter), subjective blurred vision, changes in colour vision and photophobia (glare or dazzle). This study was to investigate the effects, and their reversibility, of multiple oral doses of voriconazole on a variety of visual tests in healthy male volunteers. Thirty-six volunteers were enrolled in the study who received voriconazole (400mg every 12 hours on day one, then 300mg every 12 hours for 27.5 days). Electroretinography (ERGs) and ophthalmic examinations were carried out at screening and throughout the study period. Fifteen (83.3%) volunteers experienced >1 treatment-related visual adverse events (AEs). No serious AEs were reported. There were reduced scotopic maximal a- and b-wave amplitude, shortened implicit time and decreased oscillatory potential amplitude compared with placebo. Under photopic conditions, the 30-Hz flicker response was significantly reduced too. The study concluded that effects of voriconazole on altered visual perception, ERG, colour vision and static visual field thresholds were non progressive over a treatment period and reversible.

Reference

Effects of multiple doses of voriconazole on the vision of healthy volunteers: a double-blind, placebo-controlled study.
Zrenner E, Tomaszewski K, Hamlin J, et al.
OPHTHALMIC RESEARCH
2014;52(1):43-52

OPHTHALMIC RESEARCH

Fluorescein angiography and OCT in myopic CNV
Reviewed by: Bheemanagouda Patil
Vol 21 No 4
 

Fluorescein angiography (FA) and spectral-domain optical coherence tomography (OCT) are the most common examinations used in the management of anti-VEGF therapy in choroidal neovascularisation (CNV). In comparison to FA, OCT provides a noninvasive evaluation of the macula. Myopic CNV are generally not characterised by excessive amounts of exudation, intraretinal oedema or pigment epithelial detachment. This could limit the role of OCT in the management of myopic CNV. This study was thus aimed to evaluate the agreement between FA and SD-OCT in detecting the activity of myopic CNV during bevacizumab treatment. Thirty-four patients with subfoveal myopic CNV were prospectively enrolled. FA and SD-OCT were done at all visits. At baseline, seven eyes showed leakage on FA with no fluid on OCT and one case showed fluid on OCT and no leakage on FA. At month one, 30/34 cases showed complete concordance. They confirmed the key role of FA in diagnosing myopic CNV and reiterated that OCT may assist FA in the management of myopic CNV.

Reference

Fluorescein angiography and spectral-domain optical coherence tomography for monitoring anti-VEGF therapy in myopic choroidal neovascularisation.
Lacono P, Battaglia Parodi M, Papayannis M, et al.
OPHTHALMIC RESEARCH
2014;52(1):25-31.

OPHTHALMIC RESEARCH

Intravitreal functional plasminogen in branch retinal vein occlusion
Reviewed by: Bheemanagouda Patil
Vol 21 No 4
 

Branch retinal vein occlusion (BRVO) is the second most common vascular disorder of the eye. Intravitreal injections of anti-VEGF agents and corticosteroids have proven efficacy. Posterior vitreous cortex (PVC) adhesion has been shown to support the development of retinal vein occlusion. The induction of a complete posterior vitreous detachment (PVD) is of benefit to BRVO-affected eyes. If intravitreal plasminogen is present in eyes with BRVO, then intravitreally applied tissue Plasminogen activator (t-PA) will activate plasminogen into the active enzyme plasmin, thus facilitating PVD development. In this study, vitreous taps were taken from central vitreous body and plasminogen was functionally determined in a p-nitroanilide reaction after activation with streptokinase (100% of normal, %N = functional plasminogen in pooled normal citrated plasma). Intravitreal functional plasminogen was detected in all analysed samples (n=30) and mean plasminogen activities were found to be 0.97±1.06%N (range: 0.03-3.9%N). The study concluded that intravitreal functional plasminogen is significantly elevated in eyes with BRVO and intravitreal t-PA should be further explored to induce PVD.

Reference

Intravitreal functional plasminigen in eyes with branch retinal vein occlusion.
Bertelmann T, Sekundo W, Strodthoff S, et al.
OPHTHALMIC RESEARCH
2014;52(2):74-80.

OPHTHALMIC RESEARCH

Role of fundus autofluorescence patterns and baseline atrophy area on geographic atrophy progression
Reviewed by: Bheemanagouda Patil
Vol 21 No 4
 

Central geographic atrophy (GA) is one of the morphological sub types of late-stage macular degeneration. The natural course of the disease is characterised by expanding areas of macular atrophy, which cause absolute scotoma. Fundus autofluorescence (FAF) is derived from lipofuscin (LF) in the retinal pigment epithelium (RPE). This study was designed to investigate whether areas of increased autofluorescence (AF) surrounding the atrophic patches are associated with GA enlargement with time. Fifty-four eyes of 35 patients with GA were included in the study. Areas of GA were quantified by RegionFinder software. They concluded that areas with diffuse trickling (median 1.42mm2 / year) and banded patterns (0.81mm2 / year) might have an impact on progression. The group with baseline total atrophic of the eyes <1disc area (DA; median 0.42mm2) had an inverse relation with GA progression compared to the groups with baseline atrophy >1 disc area (p<0.05).

Reference

Geographic atrophy progression in eyes with age-related macular degeneration: role of fundus autofluorescence patterns, fellow eye and baseline atrophy area.
Batioglu F, Oguz YG, Demiral S, Ozmert E.
OPHTHALMIC RESEARCH
2014;52(2):53-9.

OPHTHALMOLOGICA

Detection of antiranibizumab antibodies in exudative AMD
Reviewed by: Sofia Rokerya
Vol 21 No 4
 

In this study the authors aimed to detect immune response to ranibizumab treatment in wet age-related macular degeneration (AMD). An ELISA was employed to quantify the anti-ranibizumab titre which was compared against the control anti-abciximab titre. Titres of anti-ranibizumab antibodies against the variable regions higher than 1:80 and at least four times higher than the control were considered positive. Anti-ranibizumab IgGs were detected in 17.1% of treated patients. No immunoreactivity was noted in the untreated (naïve) patients. For patients with 10 or fewer previous intravitreal injections (IVTs), immunisation against ranibizumab was detected in 11.1% whereas immunisation was observed in 21.7% with more IVTs (p=0.20). No record of uveitis was found in any of the patients included in the study. Factors evoking the immune response are unclear. Subconjunctival reflux may be responsible and patient related factors cannot be excluded. No attempt was made in this study to compare different patient profiles and the time interval between injections was not recorded. Immunity and drug resistance may be one of the key elements prevalent in AMD non-responders of intravitreal ranibizumab therapy, and merits further research.

Reference

Detection of antiranibizumab antibodies among patients with exudative age-related macular degeneration.
Leveziel N, Pelat T, Watier H, et al.
OPHTHALMOLOGICA
2014;232:53-6.

OPHTHALMOLOGICA

Efficacy of intravitreal dexamethasone implant in patients with persistent macular oedema
Reviewed by: Sofia Rokerya
Vol 21 No 4
 

Chronic cystoid macular oedema (CME) can develop secondary to various pathologies such as diabetic maculopathy, retinal vein occlusion and uveitis. It can cause significant visual impairment and macular damage. The therapeutic effect of corticosteroids in CME is through one or more of their properties, i.e. suppression of inflammation, vascular permeability reduction, stabilisation of endothelial tight junctions, and inhibition of synthesis of VEGF and cytokines. The purpose of this study was to examine the effect of dexamethasone drug delivery system (DEX-DDS) in patients with severely recalcitrant CME of average 20 months duration that had a poor or short-term response to other treatment modalities, i.e. intravitreal ranibizumab, intravitreal bevacizumab, intravitreal triamcinolone, periocular triamcinolone injections and / or focal / grid laser. A second goal was to compare treatment results between different CME etiologic groups (branch retinal vein occlusion [BRVO], central retinal vein occlusion [CRVO], uveitis and diabetic macular oedema [DME]). Thirty-seven eyes of 33 patients were included in the study. Eyes were categorised into three groups: diabetic macular oedema (DME, n=14), vein occlusion (n=15) and uveitis (n=7). The mean follow-up was 22±6.9 weeks. Mean age was 61.5±13.1 years (range 26-87). The average duration of CME prior to DEX-DDS injection was 20.3±16 months (range 4-68, median 15.5). Best corrected visual acuity (BCVA) improved from 0.62±0.38 to 0.35±0.29 logMAR (p<0.0001). An improvement in BCVA greater than one ETDRS line was seen in 73% of the eyes (27 of 37). Prior to DEX-DDS injection, 10 of 37 eyes (27%) presented with a BCVA of 20/40 or better. Following DEX-DDS injections, 25 of 37 eyes (68%) achieved a BCVA of 20/40 or better. At the last follow-up visit 11 of 37 eyes (30%) maintained a BCVA of 20/40 or better. A subgroup analysis of the DME, vein occlusion and uveitis groups showed no statistical difference in baseline, best-achieved and last follow-up BCVA between the groups. Central macular thickness (CMT) decreased by 184±246µm from baseline (p<0.0001). In eyes where CME resolved and recurred, the average CME-free period was 11 weeks. The patients had a total of 53 DEX-DDS injections. Thirty-seven eyes received one injection, 12 eyes received two injections, two eyes received three injections and two eyes received four injections. Mean follow-up time after a second DEX-DDS injection was 25.12 weeks. Twenty-three of 37 eyes (62%) demonstrated complete resolution of CME, achieved 6.7±4.4 weeks (median 6.1) after the injection. Nineteen eyes (51%) had CME recurrence 17.3±3.6 (range 12–25) weeks after the injection. Those 19 eyes with CME resolution and a later recurrence had a mean CME-free period of 10.7±5 weeks (range 4–21, median 10.1). The remaining 14 eyes (38%) did not reach a complete resolution of CME, but 13 of those 14 eyes did have a decrease in CME manifested in an average CMT decrease of 181µm or 33% from baseline. The uveitis group showed faster CME resolution (two weeks) and a longer CME-free period (20 weeks). Eighty-six percent of the retreated eyes were in the vein occlusion group, which also showed an overall less favourable response. This study is limited by a small cohort and its retrospective nature.

Reference

Intravitreal dexamethasone implant in patients with persistent macular oedema of variable aetiologies.
Sorkin N, Loewenstein A, Habot-Wilner Z, Goldstein M.
OPHTHALMOLOGICA
2014;232:83-91.

OPHTHALMOLOGICA

Thrombophilia in patients with retinal vein occlusion
Reviewed by: Sofia Rokerya
Vol 21 No 4
 

The authors present a retrospective study of the prevalence of thrombophilia in patients with retinal vein occlusion. The study cohort included 88 patients with central retinal vein occlusion (CRVO), 51 patients with branch retinal vein occlusion (BRVO) and 40 controls. Patients were screened for factor VIII, fibrinogen, antithrombin III, protein C, protein S, homocysteine, activated protein C (APC) resistance, ACA, factor V Leiden, prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T mutation. The most common cardiovascular risk factors were hypertension (65.8%) and prior thrombosis at any location (25%) amongst CRVO patients as well as hypertension (72.5%) and smoking (20%) amongst BRVO patients. Mean fibrinogen levels were significantly higher in all patient groups than amongst controls (CRVO: p=0.005; BRVO: p=0.004). Elevated fibrinogen levels (>4.5g/l) were significantly more frequent in the CRVO group compared to controls (p=0.037). This was not the case for the BRVO group (p=0.072). High fibrinogen levels may create hypercoagulable states by increasing blood viscosity, red blood cell aggregation, velocity of platelet aggregation and platelet reactivity. They contribute to atherosclerotic plaque growth and in vitro stabilise fibrin clots. Persistently high levels of fibrinogen might constitute an independent risk factor for RVO. However, further prospective trials to assess the potential link between elevated plasma fibrinogen and RVO have been suggested. Eight of 86 CRVO patients, three of 44 BRVO patients and none of the 39 controls were positive for ACA. Thirty of 82 CRVO patients, 23 of 43 BRVO patients and 20 of 31 controls were methylenetetrahydrofolate reductase MTHFR heterozygotes. Eleven of 82 CRVO patients, 8 of 43 BRVO patients and none of the controls were MTHFR homozygotes. There was a significantly higher rate of homozygous MTHFR mutations in the CRVO and the BRVO group, each compared to controls (CRVO: p=0.032; BRVO: p=0.011). The authors suggest elevated fibrinogen levels, ACA and the homozygous MTHFR C677T mutation as potential risk factors for CRVO / BRVO

Reference

Thrombophilia in patients with retinal vein occlusion: a retrospective analysis.
Risse F, Frank RD, Weinberger AWA.
OPHTHALMOLOGICA
2014;232:46-52.

ORBIT

The presentation of natural killer / T cell lymphoma to the oculoplastic surgeon
Reviewed by: Konal Saha
Vol 21 No 4
 

The authors present three cases of periorbital extranodal natural killer / T cell lymphoma (ENKL). Ages were 20, 45 and 55. All of these patients presented with painless eyelid swelling and a history of sinus disease. One patient had persistent bilateral panuveitis, two had extraocular muscle involvement. Initial biopsies were negative in two of the patients with repeat biopsy confirming lymphoma. The patients died at five, nine and 35 months after diagnosis despite treatment with radiotherapy and chemotherapy. The article highlights the rare presentation of ENKL to the ophthalmologist. An index of suspicion should be maintained in atypical cases of ‘orbital cellulitis’.

Reference

Series of extranodal natural killer/T cell lymphoma, nasal type, with periorbital involvement.
Termote K, Dierickxx D, Verhoef G, et al.
ORBIT
2014:33(4);245-51.

Cataract and Refractive

Anterior and posterior capsular opacification with the Tecnis ZCBOO and AcrySof SA60AT IOL
Reviewed by: Jonathan Chan
Vol 21 No 3
 

This a randomised, controlled, prospective and double-blind study comparing the anterior capsular opacification (ACO) and posterior capsular opacification (PCO) outcomes with two types of single-piece hydrophobic acrylic intraocular lenses (IOL), and AcrySof SA60AT – Group A, and Tecnis ZCBOO – Group B. A total of 148 eyes of 74 patients were recruited in the study between the age of 61-80 years of age with bilateral senile cataracts. Patients were recruited between the period of October 2009 and September 2010 at the Hospital of St. John of God (Vienna). Each patient underwent cataract surgery with implantation of an AcrySof SA60AT Group A in one eye and Tecnis ZCB00 Group B in the fellow eye by the same experienced surgeon. The lens allocation to the first or second operated eye followed a randomised process. All patients were followed up for a total of 12-months postoperatively and the PCO level was evaluated with the evaluation of posterior capsular opacification software, whereas the level of ACO and capsular retraction was evaluated and graded subjectively by the surgeons in the study. The mean PCO score was 0.1±0.17 and 0.21±0.89 in Group A and B respectively, with no statistically significant differences between the groups (p=0.47). No significant correlation was found between the PCO scores in Groups A and B (p=0.17). Regarding ACO, it was found in 15 eyes (20.3%) and two eyes (2.7%) in Groups A and B respectively (p=0.37). Anterior capsular phimosis was found in 13 eyes (17.6%) in the AcrySof SA60AT group. The incidence of glistenings was also found to only be in Group A implanted with AcrySof IOLs; the phenomenon was observed in 66.2%. The authors concluded that there were similar low rates of PCO one year after cataract surgery. It appears to be a difference in the anterior capsular opacification behaviour between the IOL models; the AcrySof SA60AT has a high incidence of ACON capsular phimosis as above. The authors suggest that the high incidence of the ACO could be related to the design of the square edge optic with exclusion of the optic-haptic junction in the Acrysof SA60AT IOL, whereas with the Tecnis IOL the square edge is continuous (360°). The high incidence of capsular phimosis suggests this could be related to the configuration of the surfaces of the IOL that may play a role in the trend to have a more significant capsular phimosis in the Acrysof group. The authors suggest this could also be related to the haptic angulation, whereas in the Tecnis group there is a biconvex IOL with aspheric anterior surface and haptic offset for three points of fixation. In the Acrysof group it is a biconvex lens with haptic angulation of 0.

Reference

Anterior and posterior capsular opacification with the Tecnis ZCBOO and AcrySof SA60AT IOL: a randomised intraindividual comparison (CR).
Kahraman G, Schrittwieser H, Walch M, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:905-9.

Cataract and Refractive

Intraoperative floppy iris syndrome and prevalence of intraoperative complications
Reviewed by: Efrosini Papagiannuli
Vol 21 No 3
 

Alpha-blockers (particularly of the selective type) are known to be associated with intraoperative floppy iris (IFIS) and poor dilation, which can present in various severities during cataract surgery and need to be recognised in order to avoid intraoperative complications. Methods used to overcome these include the use of Healon 5, iris retractors, pupil expansion rings and topical atropine. In this multicentre, retrospective study the authors assessed the prevalence of untoward events during cataract surgery in patients with IFIS and / or the use of pupillary expansion devices. Data from 4923 eyes were collected looking at the use of a-blockers, IFIS and complications like iris trauma, iris prolapse, posterior or anterior capsular tear, intraoperative vitreous prolapse and the use of pupillary expansion devices. A total of 1254 eyes (25.5%) were on alpha-blockers preoperatively and of these, 428 eyes (34.1%) had IFIS. Of the remaining 3663 eyes not on alpha-blockers, 141 eyes developed IFIS, bringing the total IFIS eyes to 569. Therefore 75.2% (428/569) of IFIS eyes were on alpha-blockers perioperatively. It is interesting to note that a large proportion of IFIS eyes were on non-selective alpha-blockers (188/627 eyes versus 229/587 eyes on selective alpha-blockers and 11/40 eyes on both). Of the IFIS eyes (569) 21.97% developed intraoperative complications, with 15.1% having one complication and 7% developing more than one complication. The corresponding figures of non-IFIS eyes were 7.6% total complications, with 4.5% having one complication and 3% more than one complication. A total of 430/4923 eyes (8.7%) had a pupillary expansion device used during surgery, of which 186 eyes (43.3%) had IFIS. Interestingly pupillary expansion devices were used in eyes on selective alpha-blockers 2.5 times more often than in IFIS eyes on non-selective alpha-blockers. The authors conclude that patients on alpha-blockers are at increased risk of IFIS, however, they also demonstrated that non-selective alpha-blockers contribute to a much higher rate of IFIS (43.9%) than previously reported. They are aware of the study limitations secondary to selection bias (predominantly male patients), its retrospective nature, some missing data and possible mis-classifications / under-reporting due to the lack of a standard definition for IFIS. Another limiting factor that is pointed out is that only mechanical pupillary expansion devices were captured and therefore pharmacological means of pupillary expansion may have been missed out, which in part may explain the low utilisation.

Reference

Intraoperative floppy iris syndrome and prevalence of intraoperative complications: results from ophthalmic surgery outcomes database.
Vollman DE, Gonzalez-Gonzalez LA, Chomsky A, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2014;157:1130-5.

Cataract and Refractive

LASEK vs. epi-LASIK for myopia: meta-analysis
Reviewed by: Anjali Gupta
Vol 21 No 3
 

Previous studies have produced inconsistent conclusions on the relative benefits between LASEK vs. Epi-LASIK. LASEK uses 20% alcohol to separate an epithelial flap from the Bowman membrane. After ablation, the epithelial flap is repositioned onto the cornea. Epi-LASIK creates the epithelial flap using a microkeratome-like instrument, the epikeratome. Theoretically, as it preserves the basement membrane and avoids the use of chemical agents, it offers faster epithelium healing and less postoperative pain than LASEK. This meta-analysis consisting of three randomised control trials (RCTs) and three non-randomised cohort studies compared differences in safety, efficacy, predictability, epithelial healing time and corneal haze formation between LASEK and Epi-LASIK. The meta-analysis included 517 eyes from six studies with myopia ranging from 0 to -9.00D. No significant differences were found in the proportion of eyes with uncorrected visual acuity (VA) of 6/6 or better, mean postoperative uncorrected VA, healing time of corneal epithelium, final proportion of eyes losing two or more lines of best spectacle corrected VA and corneal haze levels. The authors concluded that although this meta-analysis demonstrated similar safety and efficacy between LASEK and Epi-LASIK, more data is required to detect the potential differences between the two procedures.

Reference

Laser-assisted sub epithelial keratectomy versus epipolis laser in situ keratomileusis for myopia: a meta-analysis of clinical outcomes.
Wen D, Huang J, Li X, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:323-33.

Cataract and Refractive

Visual acuity after cataract surgery in AMD patients
Reviewed by: Brian Ang
Vol 21 No 3
 

The data from this study are obtained from the Age-Related Eye Disease Study (AREDS) 2 and analysed to evaluate if cataract surgery benefits patients with concurrent age-related macular degeneration (AMD). The AREDS 2 was a five year, prospective, multi-centre randomised controlled trial of nutritional supplements for the treatment of AMD. Of the 8406 eyes from 4203 study participants, 1232 eyes of 793 patients underwent cataract surgery during the study. When adjusted for age, gender and severity of cataract, eyes with mild AMD gained 11.2 letters, eyes with moderate AMD gained 11.1 letters, eyes with severe AMD gained 8.7 letters, and eyes with advanced AMD gained 6.8 letters. This study was not designed for this purpose and thus has several shortcomings, including lack of uniform postoperative follow-up periods. Nevertheless, the large patient numbers and longitudinal follow-up are major strengths of the study. The study confirms that cataract surgery can improve the visual acuity significantly in AMD patients, whether mild, moderate, severe or advanced. AMD patients should not be discouraged from undergoing cataract surgery on account of their guarded prognosis as visual benefits may be achieved.

Reference

Visual acuity after cataract surgery in patients with age-related macular degeneration.
Age-Related Eye Disease Study 2 Research Group.
OPHTHALMOLOGY
2014;121:1229-36.

Cornea and External Eye Disease

Adjunctive topical 5-FU vs. MMC for surgically excised, localised OSSN
Reviewed by: Anjali Gupta
Vol 21 No 3
 

Ocular surface squamous neoplasia (OSSN) comprises a range of dysplasia including corneal-conjunctival intraepithelial neoplasia and invasive squamous cell carcinoma. The traditional treatment for localised non-invasive OSSN has been surgical excision with or without intraoperative cryotherapy. Postoperative adjunctive topical chemotherapy significantly reduces the rate of recurrence. This paper presented a long-term follow-up of two prospective non-comparative interventional case series examining recurrence and side-effect rates in patients receiving 5-FU (fluorouracil) or mitomycin C (MMC) as adjuvants to surgical excision of localised OSSN. Eighty-nine eyes were included in the 5-FU group and 64 eyes were included in the MMC group. All patients underwent complete superficial dissection of the lesion with a 2mm margin. All lesions in the 5-FU group had cryotherapy applied intraoperatively, however, cryotherapy was not available in 18.7% of cases in the MMC arm. Median follow-up was 33.6 months in the 5-FU arm and 57.9 months in the MMC arm. There were no recurrences in the MMC arm and one recurrence in the 5-FU arm. This case of recurrence was in an incompletely excised CIN III lesion with an incomplete course of adjuvant 5-FU therapy. Overall, side-effects were encountered in 69% of 5-FU cases compared with 41% of MMC cases. Sixty-two percent of 5-FU cases experienced lid toxicity vs. 0% of MMC cases. No 5-FU cases experienced allergy vs. 28% of MMC cases. Ten percent of patients in the 5-FU group developed epiphora, compared with 17% in the MMC group. The authors concluded that recurrence is rare when adjuvant 5-FU or MMC is used in surgically excised localised OSSN and although side-effects are common, the majority are transient and rarely limit compliance.

Reference

Long-term outcomes after adjunctive topical 5-fluorouracil or mitomycin C for the treatment of surgically excised, localised ocular surface squamous neoplasia.
Bahrami B, Greenwell T, Muecke S.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:317-22.

Cornea and External Eye Disease

Effect of preservative free fluoroquinolones on human corneal epithelial cells in vitro
Reviewed by: Bheemanagouda Patil
Vol 21 No 3
 

Fluoroquinolones, including second generation (ofloxacin and ciprofloxacin), third generation (levofloxacin and tosufloxacin) and fourth generation (gatifloxacin and moxifloxacin), are a group of bactericidal agents used to treat multiple ocular infections. The third and fourth generation fluoroquinolones have enhanced Gram-positive activity when compared to the earlier ones. However, long-term use of these can affect human corneal epithelial cells. This study looks at the biologic and toxic effects of these diverse generation fluoroquinolones on cultured human corneal epithelial cells. Amongst those studied were ofloxacin, levofloxacin, tosufloxacin, moxifloxacin and gatifloxacin. MTT-based calorimetric assay, lactate dehydrogenase (LDH) assay and scratch wound test were performed. Corneal epithelial cell morphologies were examined by performing inverted light microscopy and transmission electron microscopy. The study found that the fourth generation fluoroquinolones (moxifloxacin and gatifloxacin) induced greater toxic effect to the corneal epithelial cells when compared to previous generation fluoroquinolones.

Reference

Effect of fluoroquinolone eye solutions without preservatives on human corneal epithelial cells in vitro.
Oum BS, Kim M, Lee JS, Park YM.
OPHTHALMIC RESEARCH
2014;51(4):216-23.

Cornea and External Eye Disease

Inhibiting high-risk corneal allografts
Reviewed by: Graham Wallace
Vol 21 No 3
 

The cornea is an immune privileged site and as such corneal transplants are very successful. However, in situations where this privilege is lost the failure rises substantially. To combat rejection inhibition of the immune responses depends on steroids and other immunosuppressive drugs, which are not always successful and sometimes have severe side-effects. In this paper the T cell receptor immunoglobulin and mucin domain (Tim) family member Tim1 was investigated. Tim1 is not expressed in naive CD4+ but is upregulated on the cell surface when activated, particularly on Th2 cells that are normally involved in allergic responses. To induce a high-risk transplant Balb/c mice were transplanted with corneas from C57BL/6 mice, which have different transplantation antigens and so will be recognised as foreign. Transplanted mice were either treated with RMT1-10, an anti-Tim1 monoclonal antibody or an isotype control. In RMT1-10 treated mice the numbers of effector immune cells were significantly decreased while T regulatory cells were significantly increased in the spleen, and allograft survival and corneal opacity were significantly increased. In vitro studies showed reduced expression of both IFN-Y and IL-4 in splenic CD4+ T cells from RMT1-10 treated animals. By comparison, expression of TGF-ß1, an anti-inflammatory cytokine was increased. Finally, RMT1-10 treated cells inhibited the delayed-type hypersensitivity in recipient mice, a model which supports a regulatory effect. The results suggest that inhibition of Tim1 can increase the regulatory arm of the immune response and decrease the inflammatory response, leading to increased allograft survival. The potential for such treatment in humans is of interest as unlike many diseases the timing of graft delivery and rejection is known and therefore delivery of inhibitory molecules easily determined.

Reference

Tim-1 blockade with RMT1-10 increases T regulatory cells and prolongs the survival of high-risk corneal allografts in mice.
Tan X, Jie Y, Zhang Y, et al.
EXPERIMENTAL EYE RESEARCH
2014;122(5):86-93.

Cornea and External Eye Disease

Neurotrophic keratitis
Reviewed by: Sofia Rokerya
Vol 21 No 3
 

The authors present an overview of the aetiology, diagnosis, current and future management options of neurotrophic keratitis. This is a degenerative corneal disease that occurs following the compromise of trigeminal innervation, leading to hypoesthesia
and / or anaesthesia. The aetiology is variable and includes herpetic infections, chemical burns, contact lens wear, lasik, keratoplasty, topical anaesthetics, glaucoma medications, surgery and pathology involving the trigeminal nerve, diabetes, and hypovitaminosis A. It may be associated with the use of neuroleptics, antipsychotics, anti-histamines, etc. Mackie’s classification is used to grade the severity of the condition. Clinically the condition may vary from punctuate epithelial erosion to corneal ulceration and may result in stromal melt and silent perforation of the globe. Management options comprise of lubricants without preservatives, punctual plugs, antibiotics for infected ulcers, bandage contact lenses, tarsorraphy and botulinum toxin induced ptosis to help healing in refractory cases. The use of steroids remains controversial as although it may improve inflammation, it is associated with increased risk of perforation. Surgical options include conjunctival flaps, amniotic membrane grafts, cynoacrylate glue for perforating ulcers and keratoplasty. The newer medical therapies include autologous serum eye drops, umbilical cord serum eye drops. Some studies are proposing that the topical use of substance P (SP) insulin like growth factor -1 (IGF-1) and nerve growth factor (NGF) may play a key role in potential future treatment of neurotrophic keratitis.

Reference

Neurotrophic keratitis.
Semeraro F, Forbice E, Romano V, et al.
OPHTHALMOLOGICA
2014;231:191-7.

Glaucoma

Beliefs and adherence to glaucoma treatment
Reviewed by: Lorraine North
Vol 21 No 3
 

The aim of the study was to determine adherence rates and beliefs about glaucoma and its treatment in white Americans, African Americans, white Australians and Singaporeans of Chinese descent. A cross-sectional study of 475 glaucoma patients using topical eye drops for at least six months was carried out. Adherence was assessed using an adaptation of the self-report measure the Reported Adherence to Medication validated questionnaire. The authors found significant differences in the age, duration of treatment for glaucoma and level of education between the groups. Overall they found that self-reported rates were fairly high for all groups. For example, Singaporeans reported significantly lower understanding of their glaucoma than any other group and also believed less strongly in the ability of their eye drops to control glaucoma compared with all the other groups. African Americans were significantly more concerned about their glaucoma than any other group and also reported to be more effected emotionally by glaucoma. Australians experienced significantly more symptoms from glaucoma and believed that glaucoma had a greater impact on their life. This study revealed significant differences in self-reported adherence between glaucoma patients from diverse cultures.

Reference

Beliefs and adherence to glaucoma treatment: a comparison of patients from diverse cultures.
Rees G, Chong X-L, Cheung C, et al.
JOURNAL OF GLAUCOMA
2014;23(5):293-8.

Glaucoma

Bleb-related infection after mitomycin C trabeculectomy
Reviewed by: Brian Ang
Vol 21 No 3
 

The authors report on the results of the Collaborative Bleb-related Incidence and Treatment Study (CBIITS), which was a five year multi-centre prospective study designed to investigate the incidence of bleb-related infection following filtering surgery with mitomycin C. In this study, bleb-related infection was defined as an infection that: (1) followed trabeculectomy or phaco-trabeculectomy, (2) occurred four weeks post-surgery, and (3) demonstrates clinical signs of infection related to a filtering bleb. Patients were followed up every six months for five years. A total of 1098 eyes (1098 patients) were suitable for inclusion in the study, with 824 eyes completing the five year follow-up or reached the end point of developing bleb-related infection. While 916 eyes underwent trabeculectomy alone, 182 eyes had phaco-trabeculectomy. Of these eyes, 21 developed bleb-related infection, occurring 27.3±15.9 months after surgery. The cumulative incidence of all bleb-related infection was 2.2±0.5% over the five year follow-up, while the cumulative incidence of bleb-related endophthalmitis was 1.1±0.3%. There was no difference between trabeculectomy alone or phaco-trabeculectomy, and no difference between fornix-based and limbal-based surgery. The main risk factor for infection was bleb leak (cumulative incidence 7.9±3.1%). This is the largest study to date evaluating the incidence of bleb-related infection following mitomycin C trabeculectomy. It confirms not only the relative safety of using mitomycin-C, but also the importance of long-term monitoring for bleb leak after filtering surgery.

Reference

The 5-year incidence of bleb-related infection and its risk factors after filtering surgeries with adjunctive mitomycin C.
Yamamoto T, Sawada A, Mayama C, et al.
OPHTHALMOLOGY
2014;121:1001-6.

Glaucoma

Brimonidine day and night time IOP
Reviewed by: Lorraine North
Vol 21 No 3
 

The authors describe a randomised double masked study of 29 participants with ocular hypertension (OHT) who either self-administered 0.2% brimonidine or placebo three times daily for six weeks. Patients were seen during day time and night time visits and had measurements of aqueous flow, outflow facility, episcleral venous pressure and seated and supine IOP. Uveoscleral outflow was calculated mathematically. The authors found that the effect of brimonidine was partially dependent on both the body position of the subject during IOP measurement and the time between the last dose. They concluded that in patients with OHT brimonidine treatment for six weeks significantly reduced seated IOP during the day, however, the study had several limitations due to techniques available such as for aqueous humour dynamics and calculation uveoscleral outflow.

Reference

Daytime and night-time effects of brimonidine on IOP and aqueous humor dynamics in participants with ocular hypertension.
Fan S, Agrawal A, Gulati V, et al.
JOURNAL OF GLAUCOMA
2014;23(5):276-81.

Glaucoma

Comparison of false-negative responses in glaucoma patients and normal observers
Reviewed by: Lorraine North
Vol 21 No 3
 

The authors compared false negative rates for full threshold (FULL) and Swedish Interactive Threshold Algorithm (SITA) standard automated perimetry in healthy control subjects and glaucoma patients. Twenty-four subjects underwent visual field testing of one eye five times within six weeks (19 glaucoma and five controls) with 24-2 FULL and SITA standard perimetry. They obtained false negative response procedures that presented stimuli at nine dB greater than a previously determined threshold value at specific locations (FULL) and up to 20 dB greater than the threshold for SITA. Their results showed that the percentage of false negatives was almost twice as high with FULL testing compared with the two SITA analyses. The authors felt that this may be related to the SITA method of testing for false negatives in relatively normal areas as opposed to any location (even if it has low sensitivity) with FULL due also to high variability in damaged areas or pathologic variations.

Reference

A comparison of false-negative responses for full threshold and SITA standard perimetry in glaucoma patients and normal observers.
Johnson CA, Sherman K, Dolye C, Wall M.
JOURNAL OF GLAUCOMA
2014;23(5):288-92.

Glaucoma

Hyphema after trabeculectomy with MMC
Reviewed by: Lorraine North
Vol 21 No 3
 

The authors retrospectively reviewed the medical records of consecutive patients with glaucoma who underwent trabeculectomy with mitomycin C between June 2005 and December 2010 to determine the risk factors for hyphema after surgery. Of the 420 patients, 104 (24.8%) had hyphema. Their study identified neovascular glaucoma and anticoagulant or antiplatelet medication at trabeculectomy as being significant risk factors, subgroup analysis demonstrated that neovascularisation in the anterior chamber angle and anticoagulant or platelet medication were risk factors for postoperative hyphema whereas preoperative injection of bevacizumab reduced the likelihood.

Reference

Risk factors for hyphema after trabeculectomy with
mitomycin C.
Kojima S, Inatani M, Shobayashi K, et al.
JOURNAL OF GLAUCOMA
2014;23(5):307-11.

Neuro-Ophthalmology

Non-arteritic anterior ischaemic optic neuropathy in the Asian population
Reviewed by: Claire Howard
Vol 21 No 3
 

This article provides an evaluation of changes in visual function associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients. Visual changes were identified as a reduction in visual acuity by three Snellen lines or a deterioration of visual field. Medical records were reviewed retrospectively to provide the data. In total 50 eyes from 43 patients satisfied all the inclusion criteria. Overall, the prognosis of visual acuity in association with NAION was worse in Korean patients than in western studies. This difference may be attributed to racial differences. This study does show an improved prognosis of visual field defects but this may be accounted to the different methods used to evaluate visual fields (Goldmann perimetry in this study). The grid method was used in this review to calculate changes in visual field defects. Visual acuity and visual field defects showed improvement in approximately 30% of eyes and deterioration in approximately 10%. With visual acuity the largest changes occurred during the first month after presentation. The initial visual field defect was most likely to improve between the one and three month follow-up visit. In summary, this is reported as the first known study looking at the relationship between race and the prognosis of visual acuity in NAION. Although this has some clinically relevant elements the results are limited by a
small sample size and its retrospective design, meaning further studies are required in this area for a direct relationship to be confirmed.

Reference

Changes in visual function over time in Koreans with non-arteritic anterior ischaemic optic neuropathy.
Wong Chang J, Choi J, Suk Yu Y, Kim SJ.
NEURO-OPHTHALMOLOGY
2014;38(2):62-8.

Neuro-Ophthalmology

Reported cases of hemifield slide phenomenon
Reviewed by: Claire Howard
Vol 21 No 3
 

This article reports three cases of hemifield slide, a phenomenon whereby there is an inability to stabilise and fuse visual hemifields. It occurs with heteronymous visual field loss and is thought to result from the loss of corresponding retinal points. The shift can be a horizontal or vertical binocular dissociation of visual fields and can lead to diplopia without evidence of a muscle paresis. One of the cases discussed is a case of binasal hemianopia in whom symptoms improved with expansion of the visual fields. The other two cases were of bitemporal field defects causing hemifield slide. Both these patients underwent strabismus surgery, one of whom had adjustable suture surgery, who described changes in her visual field before, during and after the adjustment which were classic for hemifield slide. The three patients reported have described intermittent diplopia as a symptom (two cases) and missing a central strip in the binocular visual field (remaining case). Visual field improvement resolved the hemifield slide in the patients reported. This article highlights the symptoms and treatment options for this small patient group, reporting that symptoms can be difficult to correct, especially where the visual field defect persists.

Reference

Hemifield slide phenomenon as a result of heteronymous hemianopia.
Peragallo JH, Bialer OY, Pineles SL, Newman NJ.
NEURO-OPHTHALMOLOGY
2014;38(2):82-7.

Ocular Pathology and Oncology

Case series of posterior scleritis
Reviewed by: Saruban Pasu
Vol 21 No 3
 

This report aimed to facilitate the correct diagnosis of posterior scleritis, a condition which is usually overlooked or misdiagnosed. Electronic health records of 31 patients with posterior scleritis were analysed and compared to a group with isolated anterior scleritis of any kind. Eighty-four percent of patients with posterior scleritis were female. The mean age of presentation was 44 years. Pain was present in all patients, with most having subacute and unilateral inflammation. Decrease in vision (20/80 or worse at presentation and / or loss of two or more Snellen lines) was documented in 29% of patients with posterior scleritis. Sixty-eight percent had associated anterior scleritis and 26% anterior uveitis at some point during follow-up. Eighty-one percent of cases were idiopathic while psoriatic arthritis, Crohn’s disease, HLA-B27, SLE and TINU were the other associated systemic conditions. Uveitis was more frequently associated in patients younger than 40 years. The mean age of patients with posterior scleritis was lower than those with anterior scleritis. Association with a systemic disease was found more frequently in patients with isolated anterior scleritis than in those with posterior scleritis. The authors comment that visual loss is more frequent than in those with anterior scleritis. They therefore recommend that all scleritis patients should undergo B-Scan ultrasonography so as not to miss any posterior disease. Although not statistically significant, they found that the more painful eyes had a greater chance of a decrease in vision.

Reference

Clinical features and presentation of posterior scleritis: a report of 31 cases.
Gonzalez-Gonzalez LA, Molina-Prat N, Doctor P, et al.
OCULAR IMMUNOLOGY AND INFLAMMATION
2014;22(3);203-7.

Ocular Pathology and Oncology

Vital dyes in ophthalmology
Reviewed by: Khadijah Basheer
Vol 21 No 3
 

This comprehensive review gives an excellent summary of the uses and properties of the different dyes available to aid better visualisation and diagnoses in ophthalmology. The authors clearly display the pharmacological properties, molecular details, osmolarity and indications in clinical ophthalmology of all known and relevant dyes. Various dyes are used today in corneal diseases and each has unique properties that are beneficial for a specific use; for example Rose Bengal to evaluate the protective status of the pre-ocular tear film, fluorescein which indicates increased epithelial permeability and Lissamin green B that stains devitalised cells. In addition dyes have an important role in surgery, particularly cataract and vitreoretinal surgery to enable better visualisation of the anterior capsule and pre-retinal membranes respectively. The authors conclude that the field of vital dyes offers great opportunities for research in ophthalmology and that new and novel dyes need further studies to clarify the safety and optimal indications in ophthalmology.

Reference

Vital dyes in ophthalmology.
Badaro E, Novais EA, Penha FM, et al.
CURRENT EYE RESEARCH
2014;39(7):649-58.

Oculoplastic and Orbit

Does mitomycin C improve success rates in DCR surgery?
Reviewed by: Konal Saha
Vol 21 No 3
 

The authors present a meta-analysis of the use of mitomycin C (MMC) as an adjunct in dacrocystorhinostomy (DCR) surgery. Fifteen randomised control trials were included. There was a degree of heterogeneity in the surgical technique used, however, the MMC is applied to the osteotomy site intraoperatively to reduce the risk of closure. MMC at concentrations between 0.02 and 1.0mg/ml were applied for between two and 30 minutes. There was no statistically significant difference in the outcome of primary endoscopic DCR (three studies) with or without the use of MMC. There was a statistically, and clinically significant difference in the outcome of primary external DCR. The failure rate was 12.6% in the control group and 6.3% in the MMC group (nine studies). The difference in failure rate of revision endo DCR was also statistically and clinically significant dropping from 30.4% to 13.2% (three studies). The meta analysis suggests there may be a role for MMC in DCR surgery, with the current results favouring its use in primary external DCR and revision endoscopic DCR.

Reference

Meta-analysis of the adjunctive use of mitomycin C in primary and revision, external, and endonasal dacryocystorhinostomy.
Xue K, Mellington FE, Norris J.
ORBIT
2014;33(4):239-44.

Oculoplastic and Orbit

Patient-reported outcomes in oculoplastic surgery
Reviewed by: James Hsuan
Vol 21 No 3
 

This is an important if somewhat difficult to grasp article which tries to formally address the subject of patient-reported outcomes in oculofacial surgery. The authors have conducted an extensive review of the literature searching for instruments (questionnaires) which have been used to assess the success of an intervention from a patient’s perspective. The introduction explains the increasing importance of these measures, not only to prove the efficacy of an intervention, or the superiority of one treatment over another, but also the benefits to the doctor patient relationship and general delivery of care. Despite this, the authors state there is a relative lack of these tools in current practice and in oculofacial research. The paper divides the instruments which have been used into generic measures and those specific to oculoplastic conditions, and lists them in two tables. The generic table also contains the oculoplastic conditions for which each tool has been used, the most common being thyroid eye disease, blepharospasm and ptosis. The disease-specific table lists 32 publications of patient-reported outcome studies, many of which use ad hoc measures which lack repeatability and validity data. The generic tools are better developed but may lack sensitivity to the specific outcome of interest in a particular oculoplastic procedure. The authors have made no attempt to rank each tool in relation to a particular intervention, but the paper is a useful starting point for anyone considering introducing patient-reported outcomes into their practice or conducting research in this area.

Reference

Patient-reported outcomes: comprehensive analysis for the oculofacial clinician.
Ramey NA, Butt Z, Burkat CN, et al.
OPHTHALMIC PLASTIC & RECONSTRUCTIVE SURGERY
2014;30:279-89.

Paediatric Ophthalmology and Strabismology

Binocular training for amblyopia
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The clinical effectiveness of binocular investigation for amblyopia was measured. The authors had previously unsuccessfully treated patients using occlusion and / or surgery. Patients were followed for an average of six months after cessation of treatment. The study included 22 patients with strabismic or anisometropic amblyopia with a mean age of 36.2±20.3 years. They completed an average 14.5 sessions of binocular training over four to six weeks. Random dot kinematograms were presented dichoptically to both eyes. The patient had to identify the direction of motion of targets. Results showed improved visual acuity in all patients and this was maintained after six months. The mean increase in visual acuity was 0.34 logMAR and increased significantly with the number of treatment sessions completed. The age and severity of amblyopia did not predict improved visual acuity. Suppression levels for amblyopia were not reported in this study.

Reference

Binocular training reduces amblyopic visual acuity impairment.
Monsouri B, Singh P, Globa A, Pearson P.
STRABISMUS
2014;22:1-6.

Paediatric Ophthalmology and Strabismology

Brown’s syndrome surgery
Reviewed by: Fiona Rowe
Vol 21 No 3
 

Complications of surgery for Brown syndrome include under correction, extrusion of expanders and training for surgery. The authors introduced a procedure with minimal side-effects, accompanied by the application of the native tendon for superior oblique elongation. This was a prospective pilot study of congenital Brown syndrome. The surgery gives elongation of about 10mm. Fourteen patients (15 eyes) were included aged 3-20 years. Follow-up was 10-16 months duration. The mean preoperative horizontal angle was 4.7±10.4 divergence which reduced to 3.3±8.1 divergence. Mean preoperative vertical angle was 16.2±5.5 hypotropia which reduced to 5.8±3.9. Mean preoperative duction limitation was -7.2±4.5 which reduced to -1.8±1.3. The abnormal head posture improved postoperatively. One patient was under corrected’ 53% had excellent results, 40% acceptable results and 6.7% were under corrected. Clinical success was achieved in 93.3%.

Reference

The results of Brown syndrome surgery with superior oblique split tendon lengthening.
Moghadam AAS, Sharifi M, Heydari S.
STRABISMUS
2014;22:7-12.

Paediatric Ophthalmology and Strabismology

Comparison of photoscreeners
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The purpose of this study was to apply the GoCheckKids, iScreen, PlusoptiX and SPOT to young patients and developmentally challenged patients in a paediatric eye practice. One hundred and eight children were assessed with a mean age of 47 months (9-146). Eleven had developmental delay and / or autism, 11 had constant strabismus and one had nystagmus. Spherical equivalent refractive error ranged from -22 to +6DS. Ten patients had anisometropia of >2D. Twenty-seven children passed all four assessments: nine had intermittent strabismus of 10-30PD. All four instruments were found to yield good screening accuracy and are valuable in identifying treatable vision impairment early enough for amblyopia treatment to be effective. Sensitivity, specificity and inclusive results were: PlusoptiX (83, 86 and 23%), SPOT (80, 85, 4%), iScreen (75, 88 and 13%), iScreen with Delta Center Crescent (92, 88, 0%) and GoCheckKids with Delta Center Crescent (81, 91, 3%).

Reference

Performance of four new photoscreeners on pediatric patients with high risk amblyopia.
Arnold RW, Armitage MD.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:46-52.

Paediatric Ophthalmology and Strabismology

Congenital aniridia clinical features
Reviewed by: Fiona Rowe
Vol 21 No 3
 

In this study the authors investigated the various ocular and systemic features associated with congenital aniridia in Indian eyes (262 eyes of 131 patients). The median age at time of first hospital visit was eight years (one day to 73 years). There were 51% male and 49% female. Ninety-seven percent had bilateral aniridia, one unilateral and one normal. The median visual acuity at presentation was 1.0 logMAR (0.10-2.10). Fifty-six percent had horizontal jerk nystagmus. Corneal involvement was seen in 60%. Phakic lens status was in 94%. Others were pseudophakic or aphakic. Cataract was present in 38.5%, subluxation in 22%, foveal hypoplasia in 88%, vitreous opacities in 16%. A pale disc was present in 13 eyes, hypoplastic in seven eyes. Three had retinal detachment. Glaucoma was present in 36%. Males had higher proportion of associated subluxation. There was no gender preponderance for glaucoma and cataract. The authors conclude that aniridia is commonly associated with other ocular features but systemic associations were notably absent.

Reference

Clinical manifestations of congenital aniridia.
Singh B, Mohamed A, Chaurasia S, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:59-62.

Paediatric Ophthalmology and Strabismology

Conversion to strabismus and amblyopia
Reviewed by: Fiona Rowe
Vol 21 No 3
 

This study was undertaken to evaluate the incidence of true manifest strabismus, the visual acuity at school screening and whether risk of failing screening is different in those discharged at first visit or followed up. The author reviewed 248 children under the age of 30 months who had been diagnosed as pseudo strabismus or no deviation. Initial concern for referral was predominantly suspected esotropia in 133 cases. Eighty-two were discharged at their first screening visit and 166 were given a follow-up appointment. It was found that the incidence of esotropia for those who were initially otherwise normal on the first screening visit is between 2.4 and 3.4%. There is no significant difference in the risk of failing vision screening between the general population and those screened by the orthoptist. Presence of positive family history contributed to the decision to offer follow-up appointments but there was no significant difference between those discharged or followed for those that later developed esotropia.

Reference

Development of manifest strabismus and reduced visual acuity following initial normal orthoptic examination / pseudo strabismus under the age of 30 months.
Garretty T.
STRABISMUS
2014;22:26-31.

Paediatric Ophthalmology and Strabismology

IOOA and DVD surgery
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The authors report the results of bilateral modified inferior oblique (IO) transposition considering the equator in seven patients with infantile strabismus syndrome with  inferior oblique overaction (IOOA) and dissociated vertical deviation (DVD). Mean age was 4.5 years (2-7) and mean follow-up was 6.3 months. Mean distance between the lateral border of the inferior rectus insertion and equator was 5.6mm (4.5-6.5). Nine patients had IO transposed onto the equator and five were placed 1mm anterior to the equator. Preoperatively all had IOOA of ≥1.5. Postoperatively IOOA was <1+ in all cases. Six patients had DVD within 1PD and only one patient had DVD of 5PD. No cases of anti-elevation syndrome were found postoperatively. Therefore the authors propose that good surgical results are achieved with this procedure although they acknowledge the small sample size.

Reference

Modified inferior oblique transposition considering the equator for primary inferior oblique overaction (IOOA) associated with dissociated vertical deviation (DVD).
Yoo EJ, Kim SH.
STRABISMUS
2014;22:13-7.

Paediatric Ophthalmology and Strabismology

IR recession and prevention of lower lid retraction
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The authors report the efficacy in preventing lower eyelid retraction and long-term results of a new technique of inferior rectus recession for vertical strabismus. The results for 35 patients were compared with 22 patients having conventional inferior rectus recession. Inferior rectus recession was the sole operation for 26 cases of the study group. Nine also required contralateral inferior oblique recession. In the study group the mean age of onset of strabismus was 27.7±8.6 years, 80% had a satisfactory outcome and 20% were undercorrected. In the control group the mean onset of strabismus was 25.7±8.6 years, 78% had a satisfactory outcome and 22% were undercorrected. Lower eyelid retraction was significantly less for the study group than controls. The new technique recesses the deeper fibre layer including approximately 90% of inferior rectus muscle thickness that is present with preservation of anterior ciliary arteries. This avoids lower lid retraction. Otherwise there were no significant differences between groups for improvement in deviation and success ratios.

Reference

Long-term results of deeper muscle fibre recession of an inferior rectus operation.
Gokyigit B, Akar S, Kaynak P, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:17-26.

Paediatric Ophthalmology and Strabismology

LR/SR surgery for high myopia strabismus
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The authors evaluated the outcomes of a surgical procedure involving the muscle union of the superior rectus and lateral rectus muscles with and without medial rectus recession and the anatomic changes before and after surgery in 35 eyes of 20 patients. Surgery included the union of muscle bellies with suture 14-15mm posterior to the muscle insertions. Muscles were not split and were not attached to the sclera. Mean age at strabismus onset was 34.8 years ±3.1. Fifteen had bilateral high axial myopia and five were unilateral. Axial lengths were 26-36mm (mean 30.6±2.8). Mean refraction was -19.01±3.1D. Significant improvement was found in which the angle remained stable over four years follow-up. Nine eyes were cured with superior rectus / lateral rectus surgery alone. Indication for medial rectus recession was presence of positive forced duction test and tight medial rectus and the time of surgery. Mean preoperative angle of globe dislocation of 178 degrees which reduced to 101 degrees. Horizontal angle decreased from 58.6 to 6.8PD and vertical angle decreased from 12.5 to 3.3PD. Ocular movements were significantly increased postoperatively. The authors concluded this to be an effective procedure.

Reference

Surgical procedure joining the lateral rectus and superior rectus muscles with or without medial rectus recession for the treatment of strabismus associated with high myopia.
Akar S, Gokyigit B, Aribal E, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:53-8.

Paediatric Ophthalmology and Strabismology

Measuring IPD with PlusoptiX
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The authors evaluated the accuracy of the PlusoptiX A04 for measuring pupillary distance as compared to measurements taken by a trained optician. This retrospective review included 256 children who had undilated PA04 screening and had pupil distance measurement done by the optician using the L8 digital pupil distance meter. Children were aged 1-16 years: 142 ortho, 97 esotropia and 17 exotropia. The mean absolute difference for the two measures for the entire cohort was 0.3mm (SD-3.12). There was good agreement of 0.76 correlation coefficient. Agreement was less for strabismic patients at 0.8mm for esotropia. The range of measurements provided by PA04 was wider than acceptable and therefore the authors propose that this should not be preferred as a first line method.

Reference

The accuracy of the PlusoptiX for measuring pupillary distance.
Singman E, Matta N, Tian J, Silbert D.
STRABISMUS
2014;22:21-5.

Paediatric Ophthalmology and Strabismology

Melphalon treatment of retinoblastoma
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The purpose of this study was to report the authors’ experience with superselective ophthalmic artery infusion of Melphalon (SOAIM) for the treatment of five cases of unilateral sporadic retinoblastoma involving the macula. Standard therapy included a cycle of three infusions at an interval of three to four weeks each. Mean follow-up was 19 months (10-34). Globally SOAIM was well tolerated without major side-effects. Local adverse events were transient such as rash, haemorrhage and ptosis. All eyes were treated by transpupillary thermotherapy during or after the SOAIM. No enucleations were required and all patients remained alive and free of metastatic disease. The authors conclude SOAIM may be a potentially useful approach to treatment of retinoblastoma allowing the salvage of residual sight and low rate of complications. Tumour regression occurred in all cases.

Reference

Successful treatment of macular retinoblastoma with superselective ophthalmic artery infusion of melphalon.
Hadjistilianou T, Coriolani G, Bracco S, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:32-8.

Paediatric Ophthalmology and Strabismology

Review of IDeX surgical outcome measures
Reviewed by: Fiona Rowe
Vol 21 No 3
 

The authors aimed to evaluate whether or not there exists standardisation of outcome measures amongst studies in the literature reporting results of surgery for intermittent exotropia. A 10 year literature review was conducted from 2002-2012 with extraction of English language papers. Fifty-six studies met the inclusion criteria: 24 prospective and 32 retrospective. The reported outcome measures were classified into four categories: postoperative alignment, sensory status, control measures and long-term changes. Eighty-nine percent of studies used postoperative alignment as a measure of success. There were eleven different definitions of what successful alignment meant. Ten percent used sensory status, distance and near stereoacuity as measures of success. Twenty-one percent reported success as a distance angle between 0-10PD; 14% as <5PD esotropia or <10PD exotropia. The time point for reporting outcomes was two months to two years postoperative. Seven percent measured quality of life and patient reported outcome measures. The authors recommend four outcome measures for future studies including alignment, near stereoacuity, control score and quality of life score.

Reference

Standardising reported outcomes of surgery for intermittent exotropia – a systematic literature review.
Chiu AKC, Din N, Ali N.
STRABISMUS
2014;22:32-6.

Paediatric Ophthalmology and Strabismology

Use of white coat and greetings
Reviewed by: Fiona Rowe
Vol 21 No 3
 

This study was undertaken to characterise the practice patterns of paediatric ophthalmologists regarding their use of white coats and salutations in outpatient visits. A questionnaire was sent to American Association for Pediatric Ophthalmology and Strabismus (AAPOS) members with a response rate of 47.8% (n=606). Seven were excluded leaving 574 physicians and 25 fellow responses. Seventy-four percent did not routinely wear a white coat. Forty-six percent addressed parents as Mum / Dad, 33% by surname, 5% by first name and 16% by various combinations. Fellows did not address parents by first name alone. The results show that physician use of white coats runs contrary to patient and parent preferences. Practice patterns appear to concur with previously reported parental greeting preferences.

Reference

Physician use of white coats in pediatric ophthalmology.
deBenedictis CN, Liu GT, Nelson LB, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2014;51:13-6.

Retina, Vitreous and Uvea

Akimba mice, a model of human diabetic retinopathy
Reviewed by: Graham Wallace
Vol 21 No 3
 

Diabetic retinopathy (DR) is a major complication of diabetes and a growing problem as the systemic disease becomes more prevalent. DR develops insidiously from an asymptomatic form through to vascular damage that leads to oedema and breakdown of the blood-retinal barrier (BRB). The Akimba mouse is a cross between the Ins2Akita the Akita diabetes model and the trVEGF029 (Kimba) mouse in which photoreceptors transiently express VEGF. The resultant Akimba has a retinal microenvironment similar to advanced DR in humans. Fluoroscein leakage showing BRB damage was seen in the Kimba and Akimba mice but not Akita or wild-type mice. BRB damage was associated with angiogenesis. Moreover, mRNA for plasmalemma vesicle associated protein (PVLAP) a molecule only found in damaged BRB, was raised in Kimba and Akimba mice. However, pericyte drop-out, and decreased endothelial junction protein expression was seen only in Akimba mice These data suggest that the recently-developed Akimba mice which combines hyperglycaemia and high intraocular VEGF expression may be a good model for human DR.

Reference

Molecular analysis of blood-retinal barrier loss in the Akimba mouse, a model of advanced diabetic retinopathy.
Wisniewska-Kruk J, Klaassen I, Vogels IM, et al.
EXPERIMENTAL EYE RESEARCH
2014;122(5)123-31.

Retina, Vitreous and Uvea

B-scan ultrasonography
Reviewed by: Nana Theodorou
Vol 21 No 3
 

B-scan ultrasonography is commonly employed for the diagnosis and follow-up of ocular trauma. This retrospective study looked at the accuracy and predictive ability of B-scan ultrasonography following open globe repair. Of the 965 patients identified with open globe injuries at the Massachusetts Eye and Ear Infirmary, 210 patients were considered suitable for B-scan ultrasonography. The time of scan ranged from day one to five years with a median of nine days after the repair. Mean patient age was 43 years with 73% of the patients been male. The team analysed 427 scans with the main outcome measure as the final visual acuity. The scan analysis revealed 59 serous choroidal detachments, 57 retinal detachments, 47 haemorrhagic choroidal detachments, 19 retinal tears, 18 vitreous traction and 10 kissing choroidal detachments. The ultrasound had a 100% positive predictive value for diagnosing retinal detachment and intraocular foreign body. The authors conclude B-scans are cost-effective and reliable for assessing open globe injuries.

Reference

B-scan ultrasonography following open globe repair.
Andreoli MT, Yiu G, Hart L, et al.
EYE
2014;28:381-5.

Retina, Vitreous and Uvea

Early surgery for epiretinal membrane
Reviewed by: Nana Theodorou
Vol 21 No 3
 

This was a retrospective case review study in 120 consecutive patients with idiopathic epiretinal membrane. The average patient age was 72 years with a mean follow-up of 6.5 months. Inclusion criteria consisted of symptomatic patients with visual acuity of 1.0 LogMAR or better (VA was measured in Snellens). Preoperatively patients were either pseudophakic or underwent combined phaco–vitrectomy. The mean preoperative VA was 0.44 LogMAR and postoperatively the mean VA was 0.23 showing statistically significant results. Two patients underwent repeat vitrectomy. Evaluation of parameter coefficients indicated that a delay in surgical procedure corresponded to a decrease in VA units. The procedures were classed as early, medium or late. This study serves as evidence that early surgery in these patients is indicated to achieve good VA outcomes with the need of further studies into timing and prognosis.

Reference

Early surgery for epiretinal membrane preserves more vision for patients.
Andreoli MT, Yiu G, Hart L, et al.
EYE
2014;28:410-4.

Retina, Vitreous and Uvea

Effect of laser wavelength on delivering effective burns through opaque lens using pattern scan laser
Reviewed by: Bheemanagouda Patil
Vol 21 No 3
 

Panretinal photocoagulation (PRP) has been used in the treatment of various retinal disorders for many decades. Conventional single-spot lasers take quite some time to do with significantly higher pain, anxiety and photophobia when compared to the pattern scan laser (PSL). It has been shown in previous studies that conventional single spot laser with longer wavelength, such as red (647nm) and yellow (568nm), showed better efficacy in delivering laser burns when compared to green argon (514nm) laser. This study evaluates the effects of pattern scan laser wavelength in delivering appropriate laser burns to mice retina through an opaque lens. Three eyes with clear lenses were used as controls. With the green laser, there were only 3.0±2.0 appropriate laser burns in eyes with opaque lens compared to 13.7±4.0 effective burns in eyes with clear lens. On the other hand, longer wavelength lasers produced 18±5.2 (yellow) and 13±1.5 (red) appropriate laser burns in eyes with opaque lens. The study concluded that pattern scan lasers with longer wavelengths produced more effective laser burns when compared to pattern scan green laser.

Reference

Effect of laser wavelength on delivering appropriate laser burns through the opaque lens using a pattern scan laser.
Hirano T, Lesato Y, Imai A, et al.
OPHTHALMIC RESEARCH
2014;51(4):204-9.

Retina, Vitreous and Uvea

MicroRNA mediate retinoblastoma signal transduction
Reviewed by: Graham Wallace
Vol 21 No 3
 

MicroRNAs (miR) are small non-coding single-stranded RNA molecules, normally 22 nucleotides long. There is a large family of miR that control protein expression by binding to mRNAs, leading to their degradation. One important role of miR is in tumours where they may promote, via down-regulation of suppressor proteins, or prevention by down regulation of oncogenic proteins. In this study miR21, which has been shown to be involved in proliferation, metastasis and anti-apoptosis of tumour cells, was analysed in retinoblastoma. miR21 expression was increased in a human Rb cell line, HXO-RB44, and Rb tissue, compared to normal retinal tissue. Antisense-miR (22 nucleotides), or seed-targeting 8mer oligonucleotides, transfected into cells led to a significant decrease in proliferation, migration and colony-forming in vitro. Antisense miR downregulated miR21 levels while the 8mer oligonucleotide did not. To determine the pathways involved in the inhibition phosphorylation status of HXO-RB44 cells treated with anti-MiR21 was assessed. Levels of phosphorlyated signal proteins such as BAD and Akt were downregulated. The data supports a role for miR21 in retinoblastoma and that inhibition of this miR could have therapeutic value.

Reference

Seed-targeting anti miR-21 inhibiting malignant progression of retinoblastoma and analysis of their phosphorylation signalling pathways.
Ding Y, Wu M, Liu J, et al.
EXPERIMENTAL EYE RESEARCH
2014;122(5):1-8.

Retina, Vitreous and Uvea

Progression of myopic maculopathy after treatment
Reviewed by: Sofia Rokerya
Vol 21 No 3
 

The authors report on a retrospective study carried out to evaluate long-term progression of myopic maculopathy and functional outcome in eyes treated for myopic choroidal neovascularisation (CNV) and in eyes without CNV. Fifty-four myopic eyes of 30 patients were included in the study. Data was obtained by medical records. Eyes were assigned to four groups (PDT, IVR, PDT + IVR, dry myopic maculopathy) and evaluated for best-corrected visual acuity, colour fundus photography and spectral-domain optical coherence tomography. Chorioretinal atrophy progression was quantified manually by a certified grader in all colour fundus photographs and also in the fundus autofluorescence (FAFs) performed during the last visit, using RetmarkerAMD® software (Critical Health SA, Portugal), a semi automated system. No significant differences in morphological and functional outcomes were found, on a long-term basis for three different therapeutic modalities - PDT, IVR and PDT + IVR. The morphological changes in treated eyes are more likely to be related with the natural progression of the myopic maculopathy than with the treatment modality. In eyes treated for CNV the area of macular atrophy increased significantly until the final evaluation. This reconfirms previous reports that chorioretinal atrophy can develop long after CNV has regressed, both in treated and non-treated eyes. More studies with long-term follow-up are needed to determine the real efficacy of different treatments for myopic CNV. Less myopic eyes had a better final BCVA (r=0.437, p=0.012, and r=0.458, p=0.006 respectively). Final BCVA was also inversely correlated with total and central areas of macular atrophy, (p < 0.01). Limitations of the study include the small sample size and the lack of a control group.

Reference

Progression of myopic maculopathy after treatment of choroidal neovascularization.
Farinha CL, Baltar AS, Nunes SG, et al.
OPHTHALMOLOGICA
2014;231:211-20.

Retina, Vitreous and Uvea

Ranibizumab versus laser in diabetic macular oedema (LUCIDATE study)
Reviewed by: Efrosini Papagiannuli
Vol 21 No 3
 

The aim of this study was to compare the functional and structural effects of Ranibizumab versus macular laser treatment in patients with diabetic macular oedema. It was a single centre, prospective, randomised, single masked clinical trial spanning a 48 week period. Thirty-three eyes of 33 patients with centre involving diabetic macular oedema were included, with best corrected visual acuity of 55-79 ETDRS letters at baseline. At baseline they were randomised 2:1 to either three loading doses of Ranibizumab with re-treatment as required every four weeks or macular laser, which was repeated every 12 weeks as required. The outcome measures were divided into a) structural outcomes, such as greatest linear dimension and area of foveal avascular zone, capillary drop out grade, and morphologic characteristics on spectralis OCT and b) functional outcomes, such as visual acuity, retinal sensitivity on microperimetry, electroretinograms and colour contrast sensitivity. They were reported at 12, 24 and 48 weeks. The results showed that the Ranibizumab group had gained 6.0 letters, had improved colour contrast thresholds, better retinal sensitivity and improvements in electrophysiologic function, whereas the laser group had lost 0.9 letters. Ranibizumab was also superior in improving the retinal thickness and structure in diabetic macular oedema, with no signs of progressive ischaemia. The authors therefore concluded that Rabibizumab was indeed superior to laser therapy in the treatment of diabetic macular oedema. They also felt that their comprehensive methodology could be adopted for future studies.

Reference

A randomized trial to assess functional and structural effects of Ranibizumab versus laser in diabetic macular edema (the LUCIDATE Study).
Comyn O, Sivaprasad S, Peto T, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2014;157:960-70.

Retina, Vitreous and Uvea

Resolution of mid-peripheral schisis in x-linked retinoschisis with the use of dorzolamide
Reviewed by: Huw Edward Oliphant
Vol 21 No 3
 

X-linked retinoschisis (XLRS) is an early onset hereditary retinal dystrophy. It is caused by mutations of the RS1 gene. Common manifestations of XLRS are schitic lesions at the macula, as well as infero-temporal schisis. Carbonic anhydrase inhibitors have previously been shown to reduce intraretinal cystoid spaces. This paper describes the resolution of a mid-peripheral schisis with the use of topical dorzolamide. In this case a 34-year-old male presented with long standing difficulties with both near and distance vision, with a best corrected visual acuity of 20/40-2 in either eye. Spectral domain optical coherence tomography (SD-OCT) demonstrated macular schisis as well as a mid-peripheral schisis. A diagnosis of XLRS was made with a finding of a mutation within the RS1 gene. The patient was treated with 2% topical dorzolamide three times a day, for three months. At three month review, a definite reduction in the intraretinal cystic spaces was found with a reduction in the intraretinal spaces in the mid peripheral retina as well. Vision was not significantly altered, being 20/40+2 in either eye at review. This is the first report of this nature, and demonstrates the potential of using carbonic anhydrase inhibitors in XLRS, and that it may be of at least some use. The correlation with visual function is still unsure.

Reference

Resolution of mid-peripheral schisis in x-linked retinoschisis with the use of dorzolamide.
Collison FT, Genead MA, Fishman GA, et al.
OPHTHALMIC GENETICS
2014;35(2):125-7.

Retina, Vitreous and Uvea

The choroid in pregnancy
Reviewed by: Khadijah Basheer
Vol 21 No 3
 

During pregnancy there can be different types of ocular changes including a decrease in corneal sensitivity, increase in central corneal thickness and curvature, decrease in intraocular pressure, central serous chorioretinopathy and ocular blood flow. Advances in ophthalmic imaging devices has allowed for more detailed understanding of the choroid, which is responsible for the majority of ocular blood flow. This study evaluated the subfoveal choroidal thickness measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in pregnant women and compared their results to age matched non-pregnant controls. They found that the mean subfoveal choroidal thickness in their study group was significantly thicker by an average of 40 microns. There was no significant correlation between subfovealchoroidal thickness and spherical refraction, intraocular pressure, axial length, central corneal thickness, ocular perfusion pressure, gestational age, maternal weight gain or foetal weight. The results from this study leave much to be answered, as we cannot tell from these results alone the significance of choroidal thickening in pregnancy. They put forward the idea that the increased choroidal thickness may be secondary to other physiological changes during pregnancy such as decrease in total vascular resistance, plasma protein concentrations and total plasma osmolarity decrease whilst the cardiac output and blood pressure remain unchanged. This study does show that the choroid can be seen in more detail using EDI-OCT and this may be able to give us more information in other cases where choroidal thickness is found to be abnormal such as age-related macular degeneration and myopia.

Reference

Evaluation of subfoveal choroidal thickness in pregnant women using enhanced depth imaging optical coherence tomography.
Kara N, Sayin N, Pirhan D, et al.
CURRENT EYE RESEARCH
2014;39(6):642-7.

Retina, Vitreous and Uvea

Uveitis in HIV infected persons
Reviewed by: Anjali Gupta
Vol 21 No 3
 

Before the advent of highly active antiretroviral therapy (HAART), uveitis, in particular cytomegalovirus (CMV) retinitis, was the most common cause of visual loss in patients with AIDS. HAART has altered the cause of ocular disease in HIV infected individuals by elevating the CD4 cell count. However, uveitis still occurs in this group of patients. The aim of this retrospective case series was to ascertain the spectrum of uveitis conditions in HIV infected individuals presenting with ocular inflammation when the peripheral CD4+ T lymphocyte count was over 200 cells/µL. Sixty-one patients were included in this study from seven tertiary referral inflammatory eye disease clinics in the USA. The median CD4 cell count at presentation of uveitis was 421 cells/µL. Eighty-two percent of the patients were being treated with HAART. The HIV load varied from undetectable to 137 705 copies/ml. The median was undetectable. Uveitis was unilateral in 47.5% and bilateral in 47.5% of patients. Anterior uveitis was the most common type in 47.5% of patients, followed by anterior / intermediate (16.4%), posterior (14.8%), panuveitis (14.8%), with the least common being intermediate uveitis (6.6%). The cause of the uveitis was infectious in 34.4% of patients and immunological in 27.9%. The most common infectious cause was syphilis in 16.4% of patients followed by herpetic anterior uveitis in 6.6% and acute retinal necrosis in 6.6%. Immune recovery uveitis was the most common defined immunological disorder, with all nine cases associated with previous CMV retinitis. There was no significant difference in the CD4 cell count between the infectious and immunological groups. The authors conclude that in HIV infected patients with a presenting CD4 cell count >200 cells/µL, the anatomical location of uveitis is in a similar distribution to the general uveitis population, but infectious causes of uveitis are more common (34.4% vs 15.4%), particularly ocular syphilis (16.4% vs <2%).

Reference

Uveitis in human immunodeficiency virus-infected persons with CD4+ T-lymphocyte count over 200 cells/µL.
Rose-Nussbaumer J, Goldstein DA, Thorne JE, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:118-25.

Retina, Vitreous and Uvea

Visual fields and OCT in hydroxychloroquine retinopathy
Reviewed by: Brian Ang
Vol 21 No 3
 

It has been recommended that patients on hydroxychloroquine be monitored regularly for retinopathy. However, there has not been an agreement as to the best screening test for hydroxychloroquine toxicity, which may include visual fields (VF), fundus autofluorescence, spectral domain optical coherence tomography (SD-OCT) and multifocal electroretinography. The authors report on a retrospective study of patients with hydroxychloroquine toxicity over a 20-year period. There were 150 patients who had toxicity, defined as clear parafoveal scotomas between two and six degrees on 10-2 VFs or clear parafoveal thinning and damage on SD-OCT. Eleven patients had relatively complete ring scotomas on VFs despite seemingly normal SD-OCT. However, all other patients with clear parafoveal damage on SD-OCT demonstrated some focal areas of parafoveal VF loss. This indicates that up to 10% of patients with hydroxychloroquine toxicity can manifest prominent ring scotomas first before any abnormality is seen on SD-OCT. The results from this study suggest that screening for hydroxychloroquine toxicity should include both 10-2 VF testing and SD-OCT to provide the optimum specificity and sensitivity.

Reference

Disparity between visual fields and optical coherence tomography in hydroxychloroquine retinopathy.
Marmor MF, Melles RB.
OPHTHALMOLOGY
2014;121:1257-62.

Visual Psychophysics

Blinking and driving
Reviewed by: Khadijah Basheer
Vol 21 No 3
 

Spontaneous blinking is dependent on cognitive processes and is regulated by a central pacemaker that is highly sensitive to the attention demands and cognitive workload of the visual task in hand. There is evidence of a variability in the frequency of spontaneous blinking with differing amounts of cognitive workload, for example reading, computer work, during a conversation and in silent primary gaze. In addition, saccade eye movements are accompanied by a suppression of visual input. There is evidence to suggest that saccadic suppression is stronger for small gaze shifts (such as reading) but weaker with increasing saccade amplitude. Saccades have been found to be accompanied by a blink and occur in relation to large ocular movements. This study aimed to explore the joint influence of cognitive demands and large amplitude saccades on spontaneous blink rate. Twenty volunteers were recruited and instructed to follow a 60-minute real life driving circuit while a video camera recorded ocular movements and blinking. Each volunteer was taken through five different complexity levels to increase the amount of cognitive workload. They monitored spontaneous blink rate and horizontal saccades. Saccades were classified according to their amplitude and blink-saccade pairs were also recorded. The results showed consistent responses of spontaneous blink rates and saccades within the same complexity levels, although there was high inter-subject variability. At different complexity levels there was no statistically significant difference in spontaneous blink rate. However, the number of large amplitude gaze shifts increased with complexity levels. An average of 87.5% of large amplitude saccades were accompanied by a blink, so the study concludes that the number of blink-saccade pairs increased with higher complexity levels as well. This study shows that in complex dynamic visual settings, spontaneous blinking accompanied by large amplitude saccades plays a role in counteracting the reduction in blink rate associated with high cognitive demands.

Reference

Blinking and driving: the influence of saccades and cognitive workload.
Cardona G, Quevedo N.
CURRENT EYE RESEARCH
2014;39(3):239-44.

ACTA OPHTHALMOLOGICA

Effects of topical anaesthetic on intraocular pressure
Reviewed by: Nana Theodorou
Vol 21 No 2
 

This prospective interventional study assessed the effects of repeated intraocular pressure (IOP) using Goldmann applanation tonometry and applanation resonance tonometry in six volunteers. Previous literature supports IOP reduction using repeated applanation tonometry. Repeated IOP measures were taken alternately on 12 eyes for one hour using oxybuprocaine / fluorescein in the right eye and tetracaine in the left. The left eye was photographed before and repeatedly for 20 minutes after the IOP measurements. To minimise mechanical influence, the same volunteers received the same amount of anaesthetic drops for one hour but without repeated IOP measurements. A total of 120 or 132 IOP measurements were performed per eye in one hour. Side-effects included punctate corneal erosions in four eyes with tetracaine. The results indicated a significant IOP reduction with both applanation methods greater with oxybuprocaine. The reduction was for the oxybuprocaine-treated eyes, -4.4mmHg and -3.8mmHg, respectively and in tetracaine eyes, -2.1mmHg. Additionally there was a significant drop in anterior chamber volume immediately after the IOP measurements that returned to the original level after two minutes. After one hour of receiving anaesthetic eye drops (without IOP measurements), the IOP decreased significantly in the oxybuprocaine eye for both methods, -3.1 and -1.7mmHg, respectively, but not in the tetracaine eye (P=0.72). The authors postulate that the significant reduction of IOP seen with both topical anaesthetics is possibly due to the anaesthetic effect and the movement of aqueous humor due to mechanical applanation.

Reference

Effects of topical anaesthetics and repeated tonometry on intraocular pressure.
Johannesson G, Hallberg P, Eklund A, et al.
ACTA OPHTHALMOLOGICA
2014;92:111-5.

ACTA OPHTHALMOLOGICA

Gender variations in retinopathy
Reviewed by: Nana Theodorou
Vol 21 No 2
 

The Tromso Eye Study is a substudy of the Tromso Study; a population based longitudinal study based in Norway. The extensive 5869 participants had no diabetes and were aged between 30-87 years. Retinal images from both eyes were taken using the PRONM retinal camera and were graded using the Clinical Diabetic Retinopathy And Diabetic Macular Oedema Scale. Data was also collected on risk factors from self-reported questionnaires, clinical exams and case note review. Retinopathy was present in 15% of the participants and men had a higher prevalence than women (15.9% versus 14%). All severe cases (0.4%) of proliferative retinopathy were due to retinal vessel occlusion. The authors discuss which conditions were associated with each of the genders. In men, retinopathy was associated with hypertension and HbA1c. In women it was associated with age, log-transformed urinary albumin excretion and hypertension. The authors offer an in depth discussion into the associated risk factors and conclude there is a strong association between retinopathy and blood pressure.

Reference

Sex differences in risk factors for retinopathy in non-diabetic men and women: The Tromso Eye Study.
Bertelsen G, Peto T, Lindekleiv H, et al.
ACTA OPHTHALMOLOGICA
2014;92:316-22.

ACTA OPHTHALMOLOGICA

Optical coherence tomography in patients exposed to vigabatrin
Reviewed by: Nana Theodorou
Vol 21 No 2
 

Vigabatrin is used to treat epilepsy and can lead to increased levels of gamma-aminobutyric acid (GABA) in the brain and in the retina leading to binasal visual field defects. Although not the first line of treatment for adults it is still used in epileptic children. Monitoring visual fields accurately is challenging in children hence the need for alternative testing. The study team evaluated the visual fields from adult patients attending routine clinic follow-up for vigabatrin medication. Twelve patients with suspected vigabatrin attributed visual field defects were selected for the study. They were re-examined with computerised kinetic perimetry, ff-electroretinogram (ERG) and optical coherence tomography (OCT) (2D circle scan). All patients demonstrated constricted visual fields. Comparative analysis of ff-ERG parameters showed reduced b-wave amplitudes for the isolated and the combined rod and cone responses (P<0.0001). The a-wave, reflecting photoreceptor activity, was reduced (P=0.001), as well as the summed amplitude of oscillatory potentials (P=0.029), corresponding to inner retinal function. OCT measurements demonstrated attenuation of the retinal nerve fibre layer (RNFL) in nine of 12 patients, most frequently superiorly and / or inferiorly. No temporal attenuation was found. Significant positive correlations were found between the total averaged RNFL thickness, superior and inferior RNFL thickness and reduced ff-ERG parameters. Positive correlations were also found between RNFL thickness and isopter areas. The results are encouraging and OCT measurement of the RNFL thickness may be of clinical value in monitoring patients especially children on vigabatrin therapy.

Reference

Attenuation of the retinal nerve fibre layer and reduced retinal function assessed by optical coherence tomography and full-field electroretinography in patients exposed to vigabatrin medication.
Kjellstrom U, Andreasson S, Ponjavic V.
ACTA OPHTHALMOLOGICA
2014;92:146-57.

ACTA OPHTHALMOLOGICA

Visual defects in deaf children and young adults
Reviewed by: Nana Theodorou
Vol 21 No 2
 

This literature review article serves as a great update on the current evidence relating to visual defects in the young deaf population. There is a good introduction with background information and demographic data relating to UK hearing impairment. The authors have made good use of tables to summarise a hearing loss overview and associated visual defects. The main section is divided into four sections and each section concentrates on a specific visual area such as; refractive and binocular anomalies, visual performance, ocular abnormalities and near vision. The authors incorporate current and past research findings into the allocated sections linking the findings into clinical practice. A good discussion follows with consideration into unexplored areas and the need for further studies especially in relation to near vision.

Reference

Visual performance and ocular abnormalities in deaf children and young adults: a literature review.
Hollingsworth R, Ludlow AK, Wilkins A, et al.
ACTA OPHTHALMOLOGICA
2014;92:305-10.

AMERICAN JOURNAL OF OPHTHALMOLOGY

Epiretinal membranes in uveitic macular oedema
Reviewed by: Efrosini Papagiannuli
Vol 21 No 2
 

Epiretinal membrane (ERM) formation in uveitic macular oedema is a fairly common structural complication of the retina. The authors describe a retrospective case series of 104 eyes of 77 patients with uveitic macular oedema from a tertiary centre. The treatment they received varied from regional (periocular / intravitreal) cortico-steroids, oral corticosteroids, immunosuppression or a combination of regional and oral corticosteroids. The aim of the study was to characterise the effect of the ERMs on visual acuity and on improvement or resolution of the uveitic macular oedema. The ERMs were diagnosed by two investigators with the aid of spectral-domain optical coherence tomography (OCT) and they were scored for the presence or absence of surface wrinkling. This was evident on OCT as multifocal attachments between the ERM and the internal limiting membrane, creating hyporeflective spaces between them and numerous folds along the internal limiting membrane. The outcome measures included best corrected visual acuity, central subfoveal thickness, macular oedema improvement rates (>20% reduction in central subfoveal thickness) and resolution (reduction of central subfoveal thickness <315 m). The authors identified ERMs in 72 eyes of 59 patients. There was no significant difference between eyes without ERM and eyes with ERM but no surface wrinkling. However, eyes with ERMs and surface wrinkling were associated with worse vision (>2/200) at presentation and worse mean visual acuities at three and six months. Snellen acuity at three months in eyes without ERM was 20/35, in eyes with ERM but no wrinkling 20/47 and in eyes with ERM and wrinkling 20/94. Similarly at six months mean visual acuity in eyes without ERM was 20/36, in eyes with ERM but no wrinkling 20/46 and in eyes with ERM and wrinkling 20/110. In terms of structural changes, at six months the eyes without an ERM had a mean central subfoveal thickness of 338 +/-23m, eyes with an ERM but no surface wrinkling had a mean central subfoveal thickness of 332+/-20m, whereas eyes with an ERM and surface wrinkling had mean values of 405+/-22m. The authors concluded that eyes with uveitic macular oedema aggravated by the formation of ERM with wrinkling had a poorer visual acuity outcome, worse response to treatment and thicker maculae at six months. The authors were aware of the limitation of their study because of small sample size, its retrospective nature and possible referral bias and recommended caution in interpreting their results.

Reference

Epiretinal membranes in uveitic macular oedema: effect on vision and response to therapy.
Lehpamer B, Moshier E, Pahk P, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2014;157:1048-55.

BRITISH JOURNAL OF OPHTHALMOLOGY

Ocular Trauma Scores in paediatric open globe injuries
Reviewed by: Jonathan Chan
Vol 21 No 2
 

This is a retrospective case series of 71 open globe injuries in children of less than 18 years of age, with a minimum follow-up period of one year, between 1 September 1992 to 31 July 2011, from the Eye Department of Ophthalmology of the Medical University of Graz, Austria. The aim of the study was to assess the predictive value and applicability of the ocular trauma score (OTS) for paediatric eye injuries. The OTS and paediatric OTS (POTS) parameters analysed for their impacts on visual outcome included initial visual acuity, glove rupture, endophthalmitis, perforation of the globe, retinal detachment, age, wound location (I=cornea, II=anterior 5mm of the sclera, III=posterior to zone II, as defined by the Ocular Trauma Classification Group), iris prolapse, hyphaema, organic injury object, delay of surgery >48 h, traumatic cataract and vitreous haemorrhage. All POTS and OTS parameters were routinely assessed, except for the relevant afferent pupillary defect (RAPD). The authors found that the initial visual acuities, retinal detachment, wound locations (p=0.001 each), lens injuries (p=0.001), posterior segment injuries (p=0.002), traumatic cataracts (p=0.010), hyphaema (p=0.011) and vitreous haemorrhage (p=0.026) had significant impacts on the final visual outcome. The authors reported that the assessment for the absence or presence of mild degree of relative afferent pupillary defect was difficult due to the cooperation of the trial at the time of the assessment. Therefore, calculating the OTS without evaluation of the RAPD was easily applicable for the initial examinations while remaining significantly prognostic with other parameters (p<0.001). The predictions of the POTS correlated with the actual final visual acuities (p<0.001), but several POTS variables (i.e., iris prolapse, age, organic injuries and delay of surgery >48h) had only limited impacts on visual outcome. The authors concluded that the OTS score has a very good predictive value for the visual outcome after open globe injuries in children, even without evaluation of RAPD.

Reference

Ocular Trauma Scores in paediatric open globe injuries.
Schorkhuber MM, Wackernagel W, Riedl R, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:664-8.

BRITISH JOURNAL OF OPHTHALMOLOGY

Secondary iris-claw anterior chamber lens implantation in patients with aphakia without capsular support
Reviewed by: Jonathan Chan
Vol 21 No 2
 

This retrospective, non-randomised, non-comparative, interventional study including 128 eyes of 124 patients that presented with aphakia with no capsular support. All patients consecutively underwent Artisan iris-claw intraocular lense (IOL) implantation between 1997 and 2010. The inclusion criteria were: aphakic without capsular support; significant ametropia (hyperopia) and poor binocular single corrected visual acuity with glasses or contact lenses; contact lens intolerance; presence of vitreous contacting the corneal endothelium; subluxation of a pre-existing intraocular lens in the posterior chamber of the eye; anterior chamber depth >3.0mm; corneal endothelial cell count greater >1800 cells/mm2, intraocular pressure within normal limits (with or without hypertensive drops); absence of retinal disease; and a minimum follow-up of one year. The authors reported that the mean age of the study patients was 54.55 years (range, 1-98 years). The mean follow-up period was 31.8 months (SD 23.63). The mean preoperative logarithm of the minimum angle of resolution best spectacle corrected visual acuity (BSCVA) and spherical equivalent (SE) were 0.67 ((SD) 0.53) and 9.63 D (SD 5.50), respectively. At the end of one year postoperative period, the mean logarithm of the minimum angle of resolution BSCVA improved to 0.52 (SD 0.46) (p<0.05), and remained stable for up to a period of five years. One year postoperative, the mean spherical equivalent was -0.52 (SD 2.21) (p<0.05). The mean preoperative cECC was 2237.47 cells/mm2, decreased over the years (p+0.05). At five years the endothelial cell count was 1961.40 cells/mm2. A slight but statistically significant decrease in cECC was observed (p<0.05). The main complications were: pupillary block; transient raised intraocular pressure; IOL replacement; penetrating keratoplasty; cystoid macular oedema. The authors concluded that the iris-claw IOL implantation in aphakic eyes is an effective, predictable and safe procedure in the first five years of follow-up. However, recommended long-term follow-up in prospective studies is required to demonstrate its long-term safety.

Reference

Secondary iris-claw anterior chamber lens implantation in patients with aphakia without capsular support.
Guell JL, Verdaguer P, Elies D, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:658-63.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

A review of chromosome 9p21 POAG susceptibility locus
Reviewed by: Anjali Gupta
Vol21 No2
 

Primary open angle glaucoma (POAG) is a genetically complex disease and the overall phenotype is influenced by multiple traits including intraocular pressure (IOP), central corneal thickness and structural features of the optic nerve head. Therefore, genes affecting any of these are likely to influence the risk of developing POAG. Many genome wide association studies (GWASs) have been conducted and multiple genetic loci were found to be associated with POAG. However, chromosome 9p21 was the only locus to yield a consistently strong association in subsequent replication studies across different populations including Australians, Americans, Europeans, Japanese and Afro-Caribbeans. A particularly strong association was found between the risk alleles of CDKN2B/CDKN2B-AS (cyclin-dependent kinase inhibitor 2B and 2B antisense) on 9p21 to both high tension POAG and normal tension glaucoma (NTG), but there was a greater level of significance to the NTG group. It was postulated that carriers of the risk alleles are predisposed to glaucomatous optic neuropathy either in a way that is independent of IOP or via an increased vulnerability of the retinal ganglion cells to IOP, even at levels considered normal for most of the population. CDKN2B encodes for p15INK4b, which is an inhibitor of cyclin-dependent kinase 4 that plays an important role in the maintenance of cell cycle progression. This may consequently cause retinal ganglion cell apoptosis, however, the exact molecular mechanism linking the association between CDKN2B/CDKN2B-AS1 and POAG is unknown. The authors conclude that this discovery is still a work in progress and that further research is necessary to understand the pathogenetic molecular pathways linking POAG to 9p21.

Reference

Chromosome 9p21 primary open-angle glaucoma susceptibility locus: a review.
Ng SK, Casson RJ, Burdon KP, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42:25-32.

CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Prostaglandin associated periorbitopathy
Reviewed by: Anjali Gupta
Vol 21 No2
 

Prostaglandins are known to cause periorbital adverse effects. The aim of this retrospective case series was to compare the frequency of prostaglandin associated periorbitopathy (PAP) between bimatoprost, latanoprost and travoprost users. Five PAP findings were evaluated: upper lid ptosis, deepening of the upper eyelid sulcus, dermatochalasis involution, loss of the periorbital fat pad and enophthalmos. One hundred and five consecutive patients with glaucoma or ocular hypertension were included in this study and one of the three prostaglandin drops was used in one eye for each patient for more than one month. The contralateral eye of each patient was used as a control. Fifteen patients were included in the bimatoprost group, 70 in the latanoprost group and 20 in the travoprost group. The results showed that PAP was most frequent in the bimatoprost group with at least one PAP feature found in 93.3% of bimatoprost users compared with 70% in the travoprost group and 41.4% in the latanoprost group. The most frequent PAP finding in all groups was loss of the periorbital fat pad followed by dermatochalasis involution. The deeper tissue changes (sulcus deepening, ptosis and enophthalmos) were all more frequent in the bimatoprost group than the travoprost and latanoprost groups. The authors conclude that PAP is common amongst prostaglandin users and is most severe in bimatoprost users.

Reference

Prostaglandin associated periorbitopathy in patients using bimatoprost, latanoprost and travoprost.
Kucukevcilioglu M, Bayer A, Uysal Y, Altinsoy HI.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2014;42;126-31.

CORNEA

Outcomes of corneal collagen crosslinking (CXL) in pseudophakic bullous keratopathy (PBK)
Reviewed by: Sharmina Khan
Vol 21 No 2
 

This was a retrospective non-comparative, interventional case series of 50 eyes in 50 patients with symptomatic PBK who underwent CXL (epithelium-off). Central corneal thickness (CCT), pain score, best corrected visual acuity (BCVA), and corneal transparency were recorded at baseline; at day seven, day 15; and one, three, and six months after the CXL. The mean pain score decreased from 8.1+/-0.6 at presentation to 2.1+/-0.7 on day seven (P=0.0001). Regression was seen in pain scores over six months (5.3+/-1.5). The mean CCT decreased from a preoperatively 724.8+/-78.4 to 694.9+/-77.9um by the end of the first month (P=0.0001) and remained stable at subsequent follow-up. The BCVA improved from log MAR) 2.0+/-0.5 preoperatively to log MAR 1.8+/-0.5 by the end of the first month (P=0.001). The subsequent follow-up showed a progressive deterioration in the BCVA to the preoperative levels at six months. Corneal bullae recurred in 44% (22 eyes) at six months after an initial disappearance. A significant improvement in the BCVA and a lack of recurrence of bullae were significantly associated with a thinner CCT on presentation (<700um). The authors conclude that CXL in symptomatic PBK temporarily improved pain without providing long-term improvement in the BCVA. Case selection is important with more effect seen in patients with a thinner CCT at presentation. Other reports in addition to this support the use of CXL as a useful intervention as a palliative procedure rather than for visual rehabilitation. Those with thicker CCT will have greater irreversible stromal changes and perhaps this is why the authors report a better outcome in those with thinner corneas. It may be an intervention to consider prior to a Gunderson’s flap in a painful blind eye due to bullous keratopathy.

Reference

Outcomes of corneal collagen crosslinking (CXL) in pseudophakic bullous keratopathy (PBK).
Ray NSS, Maharana PK, Sehra SV, et al.
CORNEA
2014;33:243-6.

CORNEA

Topography based keratoconus progression after corneal collagen cross-linking
Reviewed by: Sharmina Khan
Vol 21 No 2
 

Case 1 describes a 35-year-old man with progressive keratoconus (PK). His best corrected visual acuity (BCVA) was right 20/80 (-5.25/-7.75 x 85) and left 20/20 (+4.75/-5.00 x 90). His Ks were right 36.32/48.02 D and 41.15/46.41 D. Right central cornea thickness (CCT) was 327um and left 474um. There was no history of atopy or eye rubbing. In his right eye he had a PK and left eye corneal collagen crosslinking (CXL). Six months later BCVA left eye was 20/20 (+2.50/-3.50 x 100), Ks were 40.48/45.67 D. Three years later BCVA was 20/20 (+2.50/-3.25 x 100). However, there was an increase in Ks (42.74/47.36) i.e. >1.00D. Case 2 was a 29-year-old man with progressive keratoconus. His BCVA was right 20/25 (manifest refraction -1.75/-2.25 x75) and left 20/25 (manifest refraction -3.00/-1.25 x25). Ks were 41.87/43.92D right eye and 40.20/43.28D right eye. Five years later there was an increase in topographic steep K in the left eye, 40.96/45.82 by >1D, the manifest refraction was +0.75/-2.25 x 15. The right eye remained stable. Several studies have reported continued progression of keratoconus in the first year after treatment. These cases report topographic of > 1D progression after >four years post treatment without a reduction in BCVA. The mechanism behind this is not discussed in the report. The area of CXL corneal tissues remodels and regains original thickness > four years on. If the progression of ectasia continues resulting in reduction in BCVA would repeat CXL be an option if there is enough residual stromal tissue? Repeat CXL have been carried out by Seiler and others in women with progressive ectasia following hormonal changes associated with pregnancy. Kanellopoulos has re-treated patients who were first treated with epithelium on. Daya has retreated in post LASIK ectasia.

Reference

Topography based keratoconus progression after corneal collagen cross-linking.
Kymionis GD, Karavitaki AE, Grentzelos MA, et al.
CORNEA
2014;33:419-21.

CURRENT EYE RESEARCH

Complement factor B polymorphism and the phenotype of early age-related macular degeneration
Reviewed by: Huw Edward Oliphant
Vol 21 No 2
 

The relationship between complement factor H (CFH) and age-related macular degeneration (AMD) is very well known, but other genetic polymorphisms relating to AMD are more poorly understood. This study was designed to investigate the relationship between complement factor B (CFB) and early macular degeneration. Three hundred and forty-nine patients were recruited with early macular degeneration in at least one eye from Jules-Gonin University Eye Hospital in Switzerland. Patients were selected on the following criteria; early to intermediate AMD (International Classification and Grading System), no evidence of geographic atrophy or choroidal neovascularisation, over 50 years of age, no diabetic maculopathy, who could have adequate colour photographs of the macula taken, and they were also required to have a blood sample and to consent to the investigation. Severity of AMD was based on drusen size, total drusen, distribution, pigmentary abnormalities and presence of peripheral drusen. Genotyping for polymorphism CFB (R32Q, rs641153) was undertaken for all patients, with the majority being homozygotic for the major allele. This study demonstrated an association of CFB (polymorphism R32Q) with smaller drusen size and with smaller surface coverage by drusen. CFB (R32Q) was also associated with more peripheral drusen. The study is limited by a lack of demographic and environmental data concerning patients, which would clearly be relevant.

Reference

Complement factor B polymorphism and the phenotype of early age-related macular degeneration.
Mantel I, Ambresin A, Moetelli L, et al.
OPHTHALMIC GENETICS
2014;35(1):12-7.

 

CURRENT EYE RESEARCH

Pterygium ocular surface temperature
Reviewed by: Dr Khadijah Basheer
Vol 21 No2
 

This prospective study investigated the ocular surface temperature in patients with pterygia compared to those with dry and healthy eyes respectively. Previous studies have shown that patients with dry eyes show a significant decrease in ocular surface temperature on sustained eye opening compared to controls. The authors of this study argue that accurately evaluating a dry eye in patients with pterygia can be challenging as often Schirmer's tests are normal as there is no impairment of lacrimal secretion, however, tear film break up time can be used as a measure of corneal dryness. This study sought to investigate whether ocular surface temperature could be used as another benchmark to determine whether pterygium surgery is indicated. The results showed a significant decrease in ocular surface temperature in both the pterygium and dry eyes group compared to the control group. Although this study shows that there is a temperature difference similar to dry eye patients it is unclear whether clinics would consider investing in another piece of equipment to determine ocular surface dryness when dry eye is a symptom many patients are vocal about. There are other cheaper and simpler ways of evaluating dry ocular surface, mainly tear film break up time, fluorescein staining and Schirmer’s testing. Furthermore, in these financially strict times, funding for these operations has become an issue and showing a decrease in ocular surface temperature may not be sufficient to overcome this, as opposed to worsening visual acuity or astigmatism.

Reference

Evaluation of ocular surface temperature in patients with pterygium.
Gonnermann J, Maier AKB, Klein JP, et al.
CURRENT EYE RESEARCH
2014;39(4):359-64.

JOURNAL OF GLAUCOMA

Sleep positions and the effect on IOP
Reviewed by: Lorraine North
Vol 21 No 2
 

The authors describe a study to determine if sleeping at a 20 degree head up position decreases nocturnal IOP compared with lying supine in patients with and without glaucoma. They recruited 30 patients (60 eyes) 15 with glaucoma and 15 without. Patients were observed in a sleep laboratory requiring each participant to spend two non-consecutive nights at the lab. Patients slept in the flat position for the first night and with their heads at a 20 degree angle during the second night. Baseline IOP was taken at 10pm immediately after lying down whilst the patient was still awake, throughout the course of the night patients were gently awakened at two hourly intervals and IOP measured with the tonopen. All 30 patients completed the study and no patient had any evidence of angle closure. They found that the 20 degree head up position correlates with lower nocturnal IOP as compared with the supine position in both glaucoma and non glaucoma patients. There was no significant difference between the two groups.

Reference

The effect of positional changes on intraocular pressure during sleep in patients with and without glaucoma.
Lazzaro EC, Mallick A, Singh M, et al.
JOURNAL OF GLAUCOMA
2014;23(5):282-7.

NEURO-OPHTHALMOLOGY

A case report of Horner syndrome with neuromyelitis optica
Reviewed by: Claire Howard
Vol 21 No2
 

This case report details a patient diagnosed with neuromyelitis optica (NMO) with an associated left Horner syndrome. The female patient presented with neck pain and right hemibody decreased pain and temperature sensation. She then went on to develop left ptosis and miosis over the next three days. Magnetic resonance imaging of the cervical spine showed a longitudinally extensive intramedullary lesion more prominent on the left, with post-contrast enhancement extending from C2 to C5. The Horner syndrome was confirmed with 0.5% apraclonidine. In subtle cases of Horner syndrome, cocaine or apraclonidine drops can be used to confirm diagnosis although the latter is used increasingly in the clinical setting. In this case, application of 0.5% apraclonidine drops brought about a reversal of the anisocoria and eliminated the ptosis, confirming the diagnosis. Treatment for NMO has not been proven although opinion for the acute phase recommends intravenous glucocorticoids for five or more days. In this case, such treatment brought about a reduction in symptoms. Long-term immunosuppression for at least five years is recommended in cases of established NMO due to the high risk of relapse.

Reference

Horner syndrome in a case of neuromyelitis optica.
Lovera L, Jay WM, Biller J.
NEURO-OPHTHALMOLOGY
2014;38(2):78-81.

NEURO-OPHTHALMOLOGY

Correlation between structural and functional status of optic nerve and retina in multiple sclerosis
Reviewed by: Claire Howard
Vol 21 No 2
 

Multiple sclerosis (MS) involves autoimmune inflammatory demyelination and axonal degeneration in the central nervous system. Investigation of the retina and optic nerve head (ONH) is an ideal way to visualise this demyelination. This study investigates the functional and structural properties of the optic nerve and retina in patients with mildly disabling MS. A total of 134 eyes were investigated with the eyes of MS patients (some with history of optic neuritis and some without) being compared to a control group. The study also looked at correlation between the structural and functional parameters of the patients’ eyes. Results showed that MS eyes with a previous history of optic neuritis have significant loss of retinal nerve fibre layer thickness compared with healthy controls and unaffected eyes in MS patients. Overall, the structural and functional parameters were worse in MS eyes with a history of optic neuritis compared with non-optic neuritis and control eyes. Also, those with MS eyes (non-optic neuritis) were worse than healthy controls. This study is limited by small numbers as well as inclusion of only mild disability caused by MS.

Reference

Relationship between structural and functional assessment of the visual system in mildly disabled relapsing-remitting multiple sclerosis patients.
Huseyinoglu N, Ekinci M, Ozben S, Buyukuysal C.
NEURO-OPHTHALMOLOGY
2014;38(1):1-7.

NEURO-OPHTHALMOLOGY

Identification and diagnosis of thalamic haemorrhage
Reviewed by: Claire Howard
Vol 21 No 2
 

This paper presents a case of thalamic haemorrhage and discusses clinical findings, providing valuable insight into signs clinicians need to look for. The case presented is of a 76-year-old female who developed left hemiplegia and hemi anaesthesia. Ocular motility testing revealed ‘peering at the tip of the nose’ sign which presented as tonic downward deviation of both eyes and esodeviation of the left eye, with no up gaze beyond midline and abduction deficits bilaterally. Bilateral ptosis was also present. It is important for clinicians to be aware of this sign which is thought to reflect damage to the mesodiencephalic junction, so a rapid diagnosis can be reached. Thalamic stroke may also cause further neuro-ophthalmological defects such as homonymous field defects, visual neglect and pupillary abnormalities, which will vary depending on the location of the lesion.

Reference

Peering at the tip of the nose’ as a sign of thalamic haemorrhage.
Ahmad K, Kumar K.
NEURO-OPHTHALMOLOGY
2014;38(1):21-3.

NEURO-OPHTHALMOLOGY

Use of technology in low vision rehabilitation
Reviewed by: Claire Howard
Vol 21 No 2
 

This article is a review of the accessibility features available on tablets and smartphones for the visually impaired. It explains exactly what the accessibility features are, how to access them and how to use them as well as some useful ‘apps’ for people with low vision. It provides a comprehensive summary and explanation for a number of features that can be used to supplement low vision rehabilitation, along with more traditional devices such as magnifiers and close circuit televisions (CCTVs). Using smartphones and tablets in a patient’s low vision rehabilitation, in addition to traditional devices, can provide versatile options which may be less expensive as well as more socially acceptable. Some of the feature options that can be adjusted to suit a particular visual impairment include contrast, zoom, voice command and audio feedback options. Adjusting and reversing contrast is a simple yet often overlooked feature of smartphones and tablets for the enhancement of reading performance. This clinically useful review also provides a comparison between tablets, smartphones and E-reader devices in terms of price, comfort and size as well as features.

Reference

Tablet and smartphone accessibility features in the low vision rehabilitation.
Irvine D, Zemke A, Pusateri G, et al.
NEURO-OPHTHALMOLOGY
2014;38(2):53-9.

OCULAR IMMUNOLOGY AND INFLAMMATION

Acute retinal necrosis: an Indian experience
Reviewed by: Saruban Pasu
Vol 21 No 2
 

The authors of this retrospective study aimed to provide clinical outcomes in 62 eyes of 53 patients presenting with acute retinal necrosis. All eyes received intravenous acyclovir (10mg/kg tds) for 7-10 days followed by oral antiviral therapy (valaciclovir 1g tds or acyclovir 800mg five times a day). Seventy-two percent of patients were male with a mean age of 36 years. Eighty-three percent had unilateral involvement. In bilateral cases, the average duration to second eye involvement was 210 days. All presented with a main complaint of hazy vision. Two patients were HIV positive. Difference in visual acuity between initial (2.02 logMAR) and final visit (1.78 logMAR) was statistically significant. Fifty-two percent of eyes had 360 degrees of peripheral retinal involvement. Eighteen eyes had retinal detachment at presentation, while 23 eyes developed detachment during the course of the disease. Mean duration between onset of complaints and detachment was 71 days. Aqueous and vitreous samples revealed HSV in 19 and VZV in 28 eyes. No organisms were found in nine eyes. There was no significant difference between detachment rates in lasered versus nonlasered eyes. Thirty-two eyes required surgery (one for vitreous haze, 31 for retinal detachment). Recurrent detachment was seen in 14 of the 31 eyes. Extent of retinal involvement and time interval between onset of disease and start of treatment were significant parameters that affected the visual potential. The authors comment that antiviral therapy minimises progression of unilateral to bilateral disease, and eyes with less than 90% involvement had the best prognosis functionally. Early recognition and aggressive treatment is the cornerstone in managing this serious condition.

Reference

Acute retinal necrosis: clinical features, management and outcomes – a 10 year consecutive case series.
Roy R, Pal B, Mathur G, et al.
OCULAR IMMUNOLOGY AND INFLAMMATION
2014;22(3):170-4.

OPHTHALMIC GENETICS

Differences of the anterior segment parameters in children with Down syndrome
Reviewed by: Huw Edward Oliphant
Vol 21 No2
 

This cross-sectional study was designed in order to demonstrate the differences in anterior segment parameters in children with trisomy 21. This is important as it may impact on surgical planning when undertaking procedures in the anterior segment such as corneal grafting, or cataract surgery. The study looked at 38 children with trisomy 21, and 42 children with no known genetic polyploidy. All patients underwent ophthalmological assessment including; slit-lamp examination, cycloplegic refraction, intraocular pressure measurement (IOP), and Scheimpflug imaging measurement. Scheimflug imaging system (SI) acquires 3-dimensional images by illuminating the anterior segment in different meridians. A weakness of this study is that all of the cycloplegic refractions were undertaken with an autorefractor, and all intraocular pressure measurements were taken with a tonopen. Additionally, children with corneal scar or degeneration were excluded from the study, which is clearly relevant in anterior segment procedures. Comparative groups were in more or less the same age range, being 5-13 in the trisomy 21 group, and 5-12 in the control group. In the group of children with trisomy 21, 44.7% were emmetropic, 31.6% hyperopic, and 23.7% myopic. There was no significant difference in intraocular pressure measurement between the two groups. Central corneal thickness (CCT) was found to be less in the trisomy 21 group, however, and the mean pupil diameter was also significanty less when compared to the control group (but all trisomy 21 patients achieved good dilatation for cycloplegic refraction). The rationale for the finding of thinner corneas in the trisomy 21 is that this may represent the beginnings of ectatic disease. Reassuringly anterior chamber depth, angle and volume were comparable for both children with trisomy 21, and the control group. Overall this study demonstrates largely what is known already, in that significant anterior segment abnormalities lie within the cornea in individuals with trisomy 21.

Reference

Differences of the anterior segment parameters in children with Down syndrome.
Aslan L, Aslankurt M, Aksoy A, et al.
OPHTHALMIC GENETICS
2014;35(2):74-8.

OPHTHALMIC GENETICS

The prevalence of macular cysts in patients with clinical cone-rod dystrophy determined by spectral domain optical coherence tomography
Reviewed by: Huw Edward Oliphant
Vol 21 No 2
 

Cone-rod dystrophy is a progressive photoreceptor disorder which has multiple inheritance patterns. It is rare, with a prevalence of 1 in 40,000. Macular cysts are well recognised in other photoreceptor conditions such as retinitis pigments and choroideraemia, while they are less well recognised in cone-rod dystrophy. In this study 36 patients with cone rod dystrophy were enrolled into the study, with 32 having established disease, and four being new patients. Of the 32 established patients, none had previously been diagnosed with macular oedema, or for that matter had an OCT of the macula. All patients in this study had autosomal recessive subtype of cone rod dystrophy. Of the 36 patients, 17 were shown to have diffuse pigmentary degenerative changes at the macula, and the remaining 19 patients demonstrated normal or negligible ‘mottling’ within the fovea. Of the total 72 eyes that were examined, none demonstrated macular oedema on biomicrosopy or OCT imaging. All, however, did show a degree of retinal thinning. The study is useful in that it demonstrates macular oedema is not a common finding in cone rod dystrophy, but it is limited by the number of participants, and the fact that a number of the participants were related and were therefore likely to have similar genotypes.

Reference

The prevalence of macular cysts in patients with clinical cone-rod dystrophy determined by spectral domain optical coherence tomography.
Salvatore S, Genead MA, Fishman GA, et al.
OPHTHALMIC GENETICS
2014;35(1):47-50.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Analysis and outcome of explanted hydroxyapatite orbital implants
Reviewed by: James Hsuan
Vol 21 No 2
 

This is a retrospective case series over 11 years of 25 patients with exposed synthetic hydroxyapatite orbital implants who underwent explantation and simultaneous replacement with a dermis fat graft. All patients had signs of infection and had been treated with systemic and topical antibiotics, and had at least 5mm of exposed implant. Eight had had previous surgery in the form of various grafts to treat the exposure. Gram-positive cocci were found in 59%, the remaining 41% were negative. All the implants were sent for histopathological analysis which showed reduced fibrovascular in-growth and chronic inflammation. All patients did well from the dermis fat grafting; none had further orbital surgery and only four needed lid surgery, although one was volume deficient but declined further augmentation. It is unclear from the discussion whether the authors believe that poor initial surgical technique leads to exposure and secondary infection, or poor fibrovascular in-growth into the implant is the primary problem which itself results in exposure and infection. Either way it is clear that once significant exposure and infection have occurred in a porous implant, explantation is preferable to further salvage surgery. The study is useful in showing that simultaneous dermis fat grafting can be undertaken safely with good cosmetic results, and there is no need to postpone this over concerns of infection.

Reference

Management of porous orbital implants requiring explantation: a clinical and histopathological study.
Quaranta-Leoni FM, Moretti C, Sposato S, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2014;30:132-6.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Diagnosis and management of orbital vascular malformations
Reviewed by: James Hsuan
Vol 21 No2
 

This is an authoritative review of a controversial and difficult clinical area. The authors have experience of over 350 cases and provide a well-structured review of the classification and management of orbital vascular malformations. They emphasise the need to understand the haemodynamic characteristics of each lesion, which will largely determine not only its clinical behaviour but also the way it is managed. The merits of the different methods available to assess these lesions are described, and the authors stress the importance of dynamic imaging to detect distensible venous lesions, including Valsalva-augmented venous phase CT angiography (a technique described in depth in an accompanying article in the same issue). They then detail the clinical characteristics and imaging findings of the various malformations based on their haemodynamic properties and histology, from high flow arterial lesions to low flow venous and lymphatic malformations, including the mixed and complex variants. Helpful management strategies are provided, with some useful tips gained from their extensive experience, e.g. occasionally some lymphaticovenous malformations may mimic a cavernous haemangioma, but during surgery are found to have an adherent ‘stuck’ tail which would warrant a different, more cautious surgical removal. The limitations of traditional surgical techniques are described, along with newer interventions including intra-lesional sclerotherapy or glueing, either perioperatively with simultaneous excision or via endovascular and percutaneous image-guided approaches.

Reference

Vascular malformations of the orbit: classification and the role of imaging in diagnosis and treatment strategies.
Rootman J, Heran MKS, Graeb DA.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2014;30:91-104.

OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY

Success rates of primary and revision transcanalicular DCR surgery
Reviewed by: James Hsuan
Vol 21 No 2
 

Transcanalicular laser DCR is a relatively rare procedure compared to more conventional external or endo-nasal techniques. In this article the authors examine the outcomes of revision surgery following failed transcanalicular diode laser dacryocystorhinostomy (TCDL DCR), comparing a conventional external revision with a redo TCDL DCR. They reported a 25% failure rate in 176 primary TCLD DCR procedures. Eighteen of these failures underwent external DCR revision surgery with a success rate of 94.4%, and 16 underwent redo TCLD DCR with a success rate of 43.8% (p=0.002). The main differences between the two techniques are the size of the bony ostium and the creation of a formal mucosal anastamosis with sutured flaps. Previous TCLD DCR did not compromise external revision surgery, and the authors explain this is due to the osteotomy sites being different and therefore the nasal mucosa is not scarred where the flaps are formed. Interestingly the success of redo TCLD DCR is far lower than both revision external DCR and primary TCLD DCR, suggesting the cause of failure during primary TCLD DCR, principally scarring of the rhinostomy, is not adequately addressed during redo TCLD DCR. The 75% success rate of primary TCLD DCR is less than conventional external and endo-nasal non-laser methods, but it may still have a role given it is a quicker and less invasive procedure.

Reference

Comparison of revision surgeries with transcanalicular diode laser and external approaches in cases with failed transcanalicular diode laser dacryocystorhinostomy.
Buttanri IB, Ayintap E, Serin D, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2014;30:209-11.

OPHTHALMIC RESEARCH

Allergic conjunctivitis evaluation by thermography
Reviewed by: Bheemanagouda Patil
Vol 21 No 2
 

Thermography is a non-invasive imaging technique, which uses infrared radiation reflected from an object to estimate the temperature of the object. This paper evaluates the use of thermography to assess allergic conjunctivitis objectively, by using an instrument called ocular surface thermographer (OST). Thirteen asymptomatic patients, with proven seasonal allergic conjunctivitis due to cedar pollen, were included in the study. A drop of 0.025% levocabastine ophthalmic suspension was instilled in one eye and artificial tears in the other eye in a masked fashion 10 minutes prior to a conjunctival allergen challenge (CAC). Then a drop of cedar pollen solution was instilled into each eye to induce the allergic reaction. The surface temperature of the inferior conjunctiva and conjunctival injection scores were measured before and 30 minutes after the CAC. After the CAC, the temperature increased by 0.67±0.10˚C in the artificial tear eyes but only 0.21±0.06˚C in the levacobastine eyes. The score for conjunctival injection was 1.38±0.24 and the chemosis score was 0.85±0.25 for the artificial tear eyes and 0.62±0.27 and 0.08±0.08 in the levacobastine eyes (P<0.01). There was a significant correlation between the conjunctival surface temperature and severity of conjunctival allergic reaction. They conclude that OST can be used objectively to evaluate topical anti-allergic agents.

Reference

Evaluation of allergic conjunctivitis by thermography.
Hara Y, Shiraishi A, Yamaguchi M, et al.
OPHTHALMIC RESEARCH
2014;51(3):161-6.

OPHTHALMIC RESEARCH

Effect of single intravitreal injection of bevacizumab on contrast sensitivity in patients with central retinal vein occlusion
Reviewed by: Bheemanagouda Patil
Vol 21 No 2
 

Central retinal vein occlusion is the second most common retinal vascular disorder after diabetic retinopathy. There are many studies reporting the efficacy of intravitreal anti-VEGF injections for macular oedema secondary to retinal vein occlusions. This paper looks at the contrast sensitivity change after single injection of Avastin in patients with macular oedema secondary to central retinal occlusion. Sixteen eyes were included in the study. Contrast sensitivity, best-corrected visual acuity (BCVA), foveal thickness (FT) and macular volume (MV) were recorded before and after treatment with single injection of Avastin. Contrast sensitivity significantly improved at spatial frequencies – 1.5, 3, 6, 12 and 18 cycles per degree (cpd) – one month after the injection and six cpd at three month follow-up. BCVA, FT and MV also improved.

Reference

Effect of a single intravitreal bevacizumab injection on contrast sensitivity and macular thickness in eyes with macular oedema from central retinal vein occlusion: a prospective, nonrandomized, three-month follow-up study.
Preti RC, Ramirez LMV, Pimentel SLG, et al.
OPHTHALMIC RESEARCH
2014;51(3):140-5.

ORBIT

A surgical option for congenital ptosis
Reviewed by: Konal Saha
Vol 21 No 2
 

The authors describe a surgical technique to manage congenital ptosis. They present 30 patients with severe congenital ptosis, MRD1 varying between -2mm and 1mm. Intervention was carried out early to prevent amblyopia. All cases had surgery before age seven with 72% age two or less. The surgical technique involves accessing the frontalis muscle through an upper eyelid skin crease incision then fashioning a flap lateral to the supra orbital neurovascular bundle based laterally. The frontalis flap is then rotated inferiorly and fixed to the tarsal plate. Results were good with all patients having their visual axis cleared at last follow-up (mean follow-up of 27 months) and no sight-threatening complications noted. Three patients required reoperation. The technique offers a useful alternative to more established techniques for managing congenital ptosis which required only one incision, and no foreign material.

Reference

Early frontalis flap surgery as first option to correct congenital ptosis with poor levator function.
Medel R, Vasquez L, Wolley Dod C.
ORBIT
2014;33(3):164-8.

RETINA

Retinal morphology after PASCAL PRP treatment
Reviewed by: Saruban Pasu
Vol 21 No 2
 

The authors of this prospective cohort study set out to report the changes on Spectral Domain-OCT of PASCAL panretinal laser photocoagulation (PRP) treatment for proliferative diabetic retinopathy (PDR) or severe nonproliferative DR (NPDR) and the retinal morphology, from one hour to 21 weeks postoperatively. SD-OCT was performed along the vascular arcades in treated areas, imaging as many of the laser spots as possible. OCT images taken one hour after PASCAL treatment (mean power, 926±434 mW; median, 1,000 mW; n=27 eyes) demonstrated acute morphologic changes including retinal pigment epithelial (RPE) detachment. Laser burns were characterised by bands of increased optical reflectivity that localised to the outer retina, extending from the outer plexiform layer to the photoreceptor layer and RPE. Above each burn, there was upward displacement of the outer plexiform layer toward the inner nuclear layer. The retinal structure in between burns remained unaltered, with no evident damage because of the photocoagulation. RPE detachment was observed in 23 of 27 eyes imaged one hour after treatment. Of the laser spots imaged, 36.1% had RPE detachments and 48.4% of them occurred at the spot edges. Only average laser power and average laser energy were significantly associated with the percentage of pigment epithelium detachments (PEDs) observed one hour after treatment. At laser powers of 550mW or greater, RPE detachment was observed in every eye. The same was true in eyes that received an average laser energy of 12mJ or greater. No RPE detachments were seen in the one to two week follow-up group. On subsequent follow-up the burns had contracted in horizontal and vertical axis and were less reflective. Burn contraction appeared to plateau three to six weeks after treatment. There was downward deflection of the inner retina at each burn, contrasting with the upward deflection seen one hour after treatment. RPE seems morphological similar to its pre-treatment structure by three weeks. A small but significant improvement in visual acuity pre and post treatment was noted. This study provides comprehensive insight into the immediate pathophysiological changes after PASCAL treatment and the evolution of these lesions thereafter.

Reference

Acute retinal pigment epithelium detachments after photocoagulation.
Moysidis SN, Vajzovic L, Gregori G, Goldberg JL.
RETINA
2014;34(4):749-60.

RETINA

Sclerotomy suturing
Reviewed by: Saruban Pasu
Vol 21 No 2
 

This was a retrospective review of 589 consecutive cases of patients who underwent 23-gauge tranconjunctival pars plana vitrectomy. Cases were split into Type 1 vitrectomies (macular hole, ERM and simple vitreous haemorrhages) and Type 2 cases which were more complex requiring more extensive instrument use and torqueing of the globe (e.g. Rhegmatogenous retinal detachment and proliferative diabetic retinopathy with tractional retinal detachment). Clinical and surgical factors were analysed to determine their effects on suturing rates. Overall 227 (38.5%) required at least one sclerotomy suture at the end of surgery. Sixty-nine had one sutured sclerotomy, 52 had two sutured sclerotomies and 106 had three sutured sclerotomies. Surgical technique, tamponade agent and vitrectomy type had significant effects on the incidence of intraoperative suturing. A high suturing rate was observed in cases where no gas tamponade was used and also in Type 2 vitrectomy cases. The overall hypotony rate was 2.2% with a non-statistically significant difference between fluid filled and gas filled eyes. Surgeon experience did not have a significant association with suture rates. Surgical technique was the most significant risk factor for sclerotomy suturing. Differences in particular surgical steps, such as the angle of entry of the trocar, how the cannula is removed, the duration of compression of the sclerotomy site after cannula removal, the IOP at the end of the case, and tolerance for sclerotomy leakage, are all surgeon dependent and certainly affected suturing rates. The authors explain that the Type 2 cases may have had sclerotomies stretched open for longer durations, and more torque on the sclerostomies due to instrument manipulation. They also suggest that more extensive vitreous base dissection reduces the amount of ‘vitreous plugging’, which may aid in sealing the sclerotomy. They comment that careful assessment of the sclerotomy sites at the end of surgery is encouraged in all cases, especially in eyes with these risk factors.

Reference

Rate of sclerotomy suturing in 23-gauge primary vitrectomy.
Duval R, Hui JM, Rezaei KA.
RETINA
2014:34(4);679-83.

STRABISMUS

AC/A correlates
Reviewed by: Fiona Rowe
Vol 21 No 2
 

Three groups of subjects were included in this study. Group 1 had typically developing children from five to nine years with heterophoria less than 6PD. Group 2 had 19 children aged five to nine years with intermittent distance exotropia. Group 3 had 17 naïve young adults and children with near exophoria less than 6PD. Near and distance stimulus accommodative convergence to accommodation (AC/A) assessment with gradient prism cover test after 30 minutes of monocular occlusion was undertaken with a lab method of assessment. Results showed a poor or non-existent correlation between near and distance clinical AC/A ratios. Strong and significant associations were found for lab response convergence accommodation to convergence (CA/A) ratio and near clinical stimulus AC/A ratio. This suggests the near AC/A may reflect accommodative response to change in vergence cues following dissociation of prism cover test and disruption of vergence accommodation.

Reference

The clinical near gradient stimulus AC/A ratio correlates better with the response CA/C ratio than with the response AC/A ratio.
Horwood AM, Riddell PM.
STRABISMUS
2013;21:140-4.

STRABISMUS

AC/A non-linearity
Reviewed by: Fiona Rowe
Vol 21 No 2
 

This study investigated whether or not the response accommodative convergence to accommodation (AC/A) ratio in 30 visually normal subjects is linear with lens presentation order counterbalanced. Accommodative response was measured using the Shin Nippon SRW 500 infrared autorefractor. Accommodation was induced with full aperture trial lenses of strengths of -1.50, -3.00, -4.50 and -6.00DS. Heterophoria was measured with Maddox rod lens. Measurement was also taken at four metres using the modified Thorington technique. Subjects were aged 18-26 years (mean 20.3) and complete data was obtained for 23 subjects. Results showed a lack of linearity across accommodative demands with significant differences found between the -1.50, -4.50 and -6.00DS lenses. The general trend was an increasing responses AC/A with increasing accommodative stimulus. However, large variations occurred across the entire sample for different accommodative demands. No significant difference was found between myopic and non-myopic subjects.

Reference

Non-linearity of the response accommodative convergence to accommodation ratio.
Johnston MS, Firth AY.
STRABISMUS
2013;21:175-82.

STRABISMUS

Angle of deviation and psychological impact
Reviewed by: Fiona Rowe
Vol 21 No 2
 

This questionnaire-based prospective study using the Psychological Impact Questionnaire was designed to investigate whether the size of the angle of deviation, age, sex, presence of diplopia, visual acuity of the worse eye and direction of deviation are related to psychological impact (PI). Fifty patients were recruited: 26 female and 24 male. The average age was 48 years (15-84) and mean PI score was 2.3 (SD 14.3). Average horizontal deviation was 33PD (SD19.8). Two patients had a vertical deviation. There was no correlation with maximum degree of deviation and PI score for horizontal or vertical deviation. There was no correlation for age, sex, diplopia, visual acuity of the worse eye, esotropia or exotropia with PI score. A slight negative correlation was found for visual acuity of the better eye and PI score. However, this may be spurious as a result of the small sample size.

Reference

The psychological impact of strabismus: does the angle really matter?
Ritchie A, Colapinto P, Jain S.
STRABISMUS
2013;21(4):203-8.

STRABISMUS

CFEOM outcomes
Reviewed by: Fiona Rowe
Vol 21 No 2
 

This study presents the orbital and cranial magnetic resonance imaging (MRI) findings of patients diagnosed with congenital fibrosis of the extraocular muscles (CFEOM) along with the surgical procedures and outcomes for ocular motility and strabismus. Nine patients are described: three with type 1, one with type 2 and five with type 3. The condition was bilateral in four and unilateral in five cases. Infraducted primary deviation was reported in eight cases and supraducted in three. Seven cases had abnormal head posture. Eight had severe limitation of horizontal ocular movements and all had limited vertical ocular movements. Exotropia was present in four cases and esotropia in three. All unilateral cases were hypotropic. Six had aberrant movements, binocular vision was absent in eight, amblyopia was present in seven and eight had moderate / severe refractive errors. MRI revealed atrophy of at least one extraocular muscle supplied by the IIIn in all cases. Five had hypoplasia of the IIIn and one had a reduced VIn. Strabismus surgery was undertaken for four cases and two required more than one procedure. Favourable outcome was obtained in two cases. The authors conclude orbital and cranial MRI provides useful information on extraocular muscles and nerves, and surgery should be chosen based on individual findings after treatment of amblyopia and refractive error.

Reference

Congenital fibrosis of the extra ocular muscles: magnetic resonance imaging findings and surgical treatment.
Merino P, Gomez de Liano P, Fukumitsu H, et al.
STRABISMUS
2013;21:183-9.

STRABISMUS

Childhood visual development in albinism and infantile nystagmus
Reviewed by: Fiona Rowe
Vol 21 No 2
 

The authors compare monocular and binocular development measures in 16 children with albinism, 10 with infantile nystagmus (INS) and 72 with normal vision to address interocular acuity differences, crowding ratios and binocular summation rates. The children were aged between four and eight years. There was no age difference between groups. Children with albinism and INS had significantly larger interocular acuity differences than those with normal vision for the single chart and uncrowded chart but no significant differences for crowded charts. Crowding ratios were higher for children with albinism and INS for binocular crowding and the poorer eye. For the better eye, differences were significant for INS only. There was no difference for binocular summation ratios across groups. Strabismus and nystagmus amplitude significantly predicted crowding in the poorer eye for albinism.

Reference

Monocular and binocular development in children with albinism, infantile nystagmus syndrome and normal vision.
Huurneman B, Boonstra FN.
STRABISMUS
2013;21(4):216-24.

STRABISMUS

Near cue responses
Reviewed by: Fiona Rowe
Vol 21 No 2
 

The authors tested subjects with esotropia (13 constant esotropia, 16 fully accommodative esotropia and eight convergence excess) versus age-matched controls and 27 young adult emmetropes for response profiles in comparison to matched control groups. They found responses to the all-cue blur / disparity / proximal (BDP) condition suggested appropriate convergence and accommodation when changing from distance to nearer fixation. Lower response gains were found using impoverished targets and were generally due to poorer responses to near targets and not over-response to distant targets. In non-strabismic subjects they found typical slight accommodation lag for near. Accommodation lag and shallow accommodation were common in strabismic subjects also and particularly in accommodative esotropias with more vergence associated with each unit of accommodation. Children with constant esotropia with weak binocular vision showed very even cue use profiles with no clear pattern of cue use behaviour.

Reference

Accommodation and vergence response gains to different near cues characterize specific esotropes.
Horwood AM, Riddell PM.
STRABISMUS
2013;21:155-64.

STRABISMUS

Orthoptic slit-lamp
Reviewed by:
Vol 21 No 2
 

Adaptations are described that allow the slit-lamp to be used to document squint disorders. Changes are made in the observation system, illumination system, for recording clinical findings and visualisation of clinical findings. The author includes the use of minus lens in front of the slit-lamp objective to obtain a sharp image of both eyes. The narrowed angle between illuminated and observed axis is minimised by holding a 14D prism horizontally in front of the slit-lamp to illuminate the patient’s face and central corneal reflexes. Recording of results is by digital record. Documentation of results is by Microsoft Powerpoint.

Reference

The orthoptic slit lamp.
Gellrich MM.
STRABISMUS
2013;21(4):209-15.

STRABISMUS

Plusoptix referral criteria
Reviewed by: Fiona Rowe
Vol 21 No 2
 

The authors compared various referral criteria on the same group of patients to determine the sensitivity, specificity and predictive value of each. They also programmed the plusoptix to use the 2013 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) referral criteria. They performed a retrospective review of 109 patients. Amblyopic risk factors based on 2003 AAPOS referral criteria were present in 58 cases. Based on the results they recommend that vision screening programmes which use the plusoptix photoscreener should evaluate their own referral criteria and adjust them as needed. Where high sensitivity with good specificity is required, the Matta / Silbert criteria are recommended. For high specificity with reasonable sensitivity, the Arnold criteria are recommended.

Reference

A comparison of referral criteria used by the Plusoptix photoscreener.
Singman E, Matta N, Tian J, Silbert D.
STRABISMUS
2013;21:190-4.

STRABISMUS

Reduced angle after BT for postop diplopia test
Reviewed by: Fiona Rowe
Vol 21 No 2
 

The authors undertook a retrospective study to evaluate the extent of reduced deviation after Botulinum toxin (BT) when used as a postoperative diplopia test. They evaluated effect in 39 patients: 32 exotropia and seven esotropia. The same BT dose was used for all – five units in 0.1ml saline. The median preoperative angle was 40PD (16-78) at near and 40PD (12-77) for distance. The preoperative assessment for follow-up surgery was at a mean of seven months (4-16) after BT injection. Reduced angle of deviation of 15PD or more at either near or distance fixation was noted in 36% of patients. This altered the planned surgery for four cases with a change from 3-muscle to 2-muscle surgery. Reduction was more common for exotropia than esotropia.

Reference

Botulinum toxin as a postoperative diplopia test – it can also reduce the angle of deviation prior to surgery.
Ockrim Z, Weir CR, Yim JL, Cleary M.
STRABISMUS
2013;21(4):199-202.

STRABISMUS

Screening for stroke-related visual problems
Reviewed by: Fiona Rowe
Vol 21 No 2
 

The aim was to report the initial development and evaluation of a suitable screening tool for detecting visual problems after stroke. The tool has four components. The first three include questions asked by examiners about patients’ ocular history and symptoms, observations of ocular appearance and tests of eye movement responses. The fourth component identifies actions, including referral that follow from the first three questions. The authors tested the tool against data collected from 100 examinations of stroke survivors in which there were 498 ocular conditions and visual defects. The tool identified 309 (69%) with a correlation of 0.84. Non-orthoptic professionals identified 85 (17%) with a correlation on 0.34. The authors propose the use of this tool to detect visual conditions in patients with stroke with the potential to support health care practitioners in the better identification of visual function.

Reference

Towards gaining the best information about vision to assist the recovery of a patient with stroke.
Jolly N, Macfarlane A, Heard R.
STRABISMUS
2013;21:145-9.

STRABISMUS

Strabismus detection by Plusoptix S08
Reviewed by: Fiona Rowe
Vol 21 No 2
 

In this study the authors evaluate the accuracy and sensitivity of the Plusoptix S08 photoscreener in detecting strabismus problems in 83 patients aged from six months to 40 years (mean 105 months). A pass was achieved for 25 patients and 58 were referred. These included four with exophoria, 55 with esotropia, 15 with exotropia and nine with horizontal and vertical combined strabismus. The angle measured <20PD in 15 patients, 20-30PD in 24 patients, 30-40PD in 21 patients and >40PD in 21 patients. The overall sensitivity to detection of strabismus was 70%. Sensitivity increased as the deviation angle increased and particularly when >30PD. The authors conclude it cannot be used solely in evaluating strabismus due to the low sensitivity for deviations measuring <30PD.

Reference

Plusoptix S08 sensitivity in detecting strabismus as amblyogenic risk factor.
Moghadam AS, Alizadeh R, Zarei-Ghanavati M.
STRABISMUS
2013;21(4):230-4.

STRABISMUS

Strabismus outcomes after retinal detachment surgery
Reviewed by: Fiona Rowe
Vol 21 No 2
 

A retrospective study reviewed the motor outcomes of strabismus surgery in a cohort of 18 patients who had all previously undergone a scleral buckling procedure to treat retinal detachment. The mean age at strabismus surgery was 48 years (14-67) and median time from scleral buckling surgery to first strabismus surgery was 14.5 months (eight months to 19 years). The preoperative horizontal deviation ranged from 25PD esotropia to 70PD exotropia and vertical deviation ranged from 25PD right hypotropia to 35PD right hypertropia. Eight patients had both horizontal and vertical deviations, seven had horizontal deviations only and three had vertical deviations only. The overall success rate was 33% (six patients). Higher success was noted in the group that had the scleral buckle removed (62.5%) versus the scleral buckle left (10%). There were no retinal re-detachments.

Reference

Strabismus surgery outcomes after scleral buckling procedures for retinal reattachment.
Chang JH, Hutchinson AK, Zhang M, Lambert SR.
STRABISMUS
2013;21(4):235-41.

STRABISMUS

Stroke-vision symptoms
Reviewed by: Fiona Rowe
Vol 21 No2
 

The purpose of this study was to investigate the frequency and type of visual symptoms following stroke and evaluate what certain factors were associated with the absence of visual symptoms. This was a prospective, multi-centre, observation cohort study with 915 recruited patients; 59% male and mean age of 69 years (SD 14). Visual symptoms were reported by 84% (766) either as sole symptoms (56%) or combined as two or more visual symptoms (28%). Visual field loss was reported by 45%, blurred vision by 31%, reading difficulty by 19.5% and diplopia by 19%. Fifty patients had normal ocular examination despite reporting visual symptoms initially but these may have recovered by the time of examination. Sixteen percent (149) were visually asymptomatic: 22 with a normal ocular examination and 32 with aphasia. The authors conclude the presence or absence of visual symptoms does not infer absence or presence of visual impairment and may relate to recovery of visual impairment, visual impairment of mild extent and / or no visual consequence, inattention to the visual impairment or cognitive / communication impairment.

Reference

Symptoms of stroke-related visual impairment.
Rowe FJ, VIS Group UK.
STRABISMUS
2013;21:150-4.

STRABISMUS

Vision screening opinion
Reviewed by: Fiona Rowe
Vol 21 No 2
 

The aim of this paper is to describe experts’ perceptions of best practice guidelines and competency frameworks for visual screening in children. A focus group of approximately 75 minutes duration consisted of five orthoptists and two paediatric ophthalmologists with more than 10 years’ experience in childhood screening. The discussions were recorded and transcribed, followed by qualitative analysis with categorical technique using coded data and classification for conceptual categories. Participants indicated their awareness of the importance of the screening protocol with six tests, importance of false negatives, professional experience and stages in screening. Agreement was reached on six tests to include in screening for children up to three years of age including distance visual acuity, cover test, bi-prism or 4/6 prism, fusion, ocular movements and refraction. The findings provide preliminary support for the use of a core competency framework.

Reference

Expert opinion on best practice guidelines and competency framework for visual screening in children.
Lanca C.
STRABISMUS
2013;21:169-74.

Clinical and Experimental Ophthalmology

Pentacam vs. IOL Master keratometry measurement in IOL power calculations
Reviewed by: Anjali Gupta
Vol 21 No1
 

The IOL Master measures only the anterior corneal curvature and estimates the total corneal power by assuming a fixed relationship between the anterior and posterior corneal surface. The Pentacam measures both the anterior and posterior corneal surface and therefore calculates the true corneal power. The aim of this non-randomised prospective study was to assess whether the Pentacam equivalent keratometry readings (EKR) for three corneal diameter zones (2, 3 and 4.5mm) were significantly different to IOL Master 500 keratometry measurements. Forty-five consecutive patients undergoing routine phacoemulsification and intraocular lens implantation were included in the study. Each patient underwent measurements with the IOL Master and Pentacam prior to surgery. Postoperatively, for each Pentacam EKR and IOL Master measurement, the difference between the observed and expected refractive error was calculated using the Holladay 2 and SRK/T formulae. From this the mean absolute error of refraction (MAE, the distance of the mean refraction from zero) was calculated. The mean keratometric measurements were statistically different between the IOL Master and the Pentacam EKRs in the 2, 3 and 4.5mm zones. However, despite the difference in the keratometry readings, there was no significant difference between the MAE of the IOL Master, EKR 2, 3 or 4.5mm for both the Holladay 2 and SRK/T formulae.

Reference

Comparison of the Pentacam equivalent keratometry reading and IOL master keratometry measurement in intraocular lens power calculations.
Karunaratne N.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2013;41;825-34.

Clinical and Experimental Ophthalmology

Spectral domain OCT vs. confocal scanning laser ophthalmoscope in measuring RNFL thickness
Reviewed by: Anjali Gupta
Vol 21 No1
 

The aim of this prospective study was to compare the retinal nerve fibre layer thickness (RNFL) measurements obtained from the Cirrus optical coherence tomography (spectral domain OCT) with the Heidelberg Retinal Tomograph 3 (HRT3, confocal scanning laser ophthalmoscope). Eighty-eight normal subjects and 85 glaucoma subjects were included and had imaging performed with both the Cirrus OCT and HRT3. VFs with SITA 24-2 were also carried out at the same visit. HRT3 produced thicker measurements both globally and in all four quadrants compared to the Cirrus OCT. However, there was a significant strong correlation between the two imaging modalities for all paired measurements of global and sectoral RNFL. For all paired measurements, except for the nasal quadrant, Cirrus OCT showed higher sensitivities for glaucoma detection than HRT3 at similar specificities. The authors conclude that although the thickness measurements by the two technologies are strongly correlated, they are significantly different. Therefore, the measurements are not interchangeable when used in clinical practice.

Reference

Retinal nerve fibre layer imaging: comparison of Cirrus optical coherence tomography and Heidelberg retinal tomograph 3.
Kratz A, Lim R, Rush R, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2013;41:853-63.

Current Eye Research

Topical doxycycline for corneal neovascularisation
Reviewed by: Khadijah Basheer
Vol 21 No1
 

Six eyes with corneal vascularisation were treated with 1% topical doxycycline, four times a day for three weeks. The patients were reviewed at various intervals over a period of one year. The eyes selected had neovascularisation secondary to a variety of conditions, some mild for example corneal epitheliopathy, atopic disease, rosacea keratitis to more severe conditions such as diabetic rubeotic glaucoma and herpetic keratitis. The authors found that five out of six eyes with active corneal vascularisation treated with topical doxycycline showed attenuation and shortening in blood vessels. Although this is a small case series this paper concludes that topical doxycycline could be used in therapy of corneal vascularisation where corticosteroids or anti vascular endothelial growth factor agents are contraindicated or have been ineffective. Further larger studies would be useful to determine the true effectiveness of topical doxycycline on a larger variety of patients with corneal vascularisation, including corneal graft patients.

Reference

The effect of topical doxycycline on corneal neovascularisation.
Jovanovic V, Nikolic L.
CURRENT EYE RESEARCH
2014;39(2):142-8.

Eye

Avastin vs. Volon A for diabetic macular oedema
Reviewed by: Nana Theodorou
Vol 21 No1
 

This prospective randomised interventional clinical trial compared 30 diabetic patients with macular oedema treated with either intravitreal injections of bevacizumab (Avastin) or triamcinolone (Volon A). One group initially received three injections of 2.5 mg Avastin in monthly intervals whilst the second group received a single injection of 8mg Volon A, followed by two sham interventions. Functional and anatomic results were evaluated monthly using ETDRS vision charts and spectral-domain optical coherence tomography. Retreatment after three months was dependent on functional and anatomic outcome. The results showed baseline best corrected visual acuity (BCVA) was 0.30 logMAR and central retinal subfield thickness was 505µm in the Avastin group and 0.32logMAR and 490µm in the Volon A group. After three months, visual acuity improved to 0.23 logMAR (Avastin) and retinal thickness to 358µm and 0.26 logMAR (Volon A) and 308µm. After 12 months, visual acuity further recovered in the Avastin group (0.18 logMAR) but slightly decreased in the Volon A group (0.36 logMAR). Both treatments were effective in the early stages of the disease but after one year BCVA was better in the Avastin group. The authors discuss risk factors and patient selection should be taken into account when selecting appropriate treatment.

Reference

Intravitreal bevacizumab (avastin) versus triamcinolone (Volon A) for diabetic treatment of diabetic macular edema: one-year results.
Kriechbaum K, Prager S, Mylonas G, et al.
EYE
2014;28:10-6.

Eye

Latanoprost in the treatment of congenital glaucoma
Reviewed by: Nana Theodorou
Vol 21 No1
 

The aim of this study was to investigate the glaucoma control of latanoprost therapy in primary congenital glaucoma (PCG) and assess the factors affecting long-term outcome. Eighty-one eyes of 44 patients with PCG and 42 eyes of 29 patients with previous glaucoma surgery that had been treated with latanoprost as primary treatment were included, with age at treatment varying from 1 to 34 months. Patients were re-examined at a study visit to evaluate intraocular pressure, length of glaucoma control with latanoprost, need of further medication or glaucoma surgery, systemic and topical side-effects. In the first group, a success (glaucoma control by latanoprost therapy) was found in 24 eyes (29.6%), whereas 57 eyes (70.4%) had received surgery (45 eyes (55.6%) in the first year); among the eyes with previous surgery, a success was found in 12 eyes (28.6%), 13 eyes (31%) required an additional therapy and 17 eyes (40.5%) had received further glaucoma surgery. No patient discontinued the treatment because of side-effects. Factors related to the failure of the latanoprost treatment were: the high score of severity of glaucoma (P=0.014) and low age at PCG presentation (P=0.042). The authors concluded that long-term treatment with latanoprost is effective in about 30% of the eyes. Factors related to poor glaucoma control included severe glaucomatous alterations and young age at presentation.

Reference

Long-term efficacy of latanoprost in primary congenital glaucoma.
Uva MG, Avitabile T, Reibaldi M, et al.
EYE
2014;28:53-7.

Journal of Cataract and Refractive Surgery

Liquid adhesive bandage for clear corneal cataract incisions
Reviewed by: Anju Kadyan
Vol 21 No1
 

This paper reports a prospective randomised controlled trial of patients undergoing routine phacoemulsification with a 2.75mm clear corneal incision and followed up for 14 days postoperatively. They evaluated wound edge closure, surgically induced astigmatism and foreign body sensation after use of single 10/0 nylon suture or a liquid adhesive bandage compared to a control group with only stromal hydration. Patients with>0.5D astigmatism had on-axis surgery with the rest having a temporal incision, but the impact of incision site and pre-existing astigmatism was not explored across groups. Suturing was associated with the most surgically induced astigmatism (mean 1.3D) than the adhesive and control groups (mean 0.6D each) with no significant change across groups over 14 days. The adhesive group has the least foreign body sensation on visual analogue scores, followed by control group, with the highest being with suture use. The Siedel test was negative in all patients although wound edge closure assessed by fluorescein staining of wound edge was worst with hydration only. An adhesive to aid wound integrity postoperatively is an important tool in our armamentarium but the need in routine cataract surgery may not be adequately justified both in terms of time and cost. The adhesive would need evaluation in more complex cases where there is risk of wound gaping (corneal pathology / burn) or even in a wider range of intraocular procedures.

Reference

Surgical outcomes after application of a liquid adhesive ocular bandage to clear corneal incisions during cataract surgery.
Keynon KR, Uy HS.
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2013;39:1668-74.

Journal of Glaucoma

A ciliary body tumour
Reviewed by: Lorraine North
Vol 21 No1
 

The authors describe a case report of a 60-year-old woman found to have advanced angle closure glaucoma in her right eye and appositional closure of half of the left eye and no glaucoma. The patient had previously undergone two trabeculectomies to her right eye which showed advanced glaucomatous damage on visual fields; the left eye had no visual field defect and normal intraocular pressure (IOP). Gonioscopy of the right eye showed peripheral anterior synechiae for over 270 degrees completely covering the trabecular meshwork. Indentation of the left eye showed significant relative pupillary block in all quadrants with the nasal angle completely closed by apposition. The nasal trabecular meshwork was lightly pigmented and the temporal angle was open. Ultrasound biomicroscopy (UBM) was performed and showed a ciliary body tumour preventing angle closure. This case report highlights the need for careful gonioscopy.

Reference

A ciliary body tumour preventing angle closure.
Mehanna C, Desjardins L, Puech M, Cohn H.
JOURNAL OF GLAUCOMA
2014;23(2):125-6.

Journal of Glaucoma

Canaloplasty after failed trabeculectomy
Reviewed by: Lorraine North
Vol 21 No1
 

The authors describe the technique of canaloplasty performed in five patients who had undergone previous trabeculectomy and under maximum tolerated medical therapy or insufficient intraocular pressure (IOP) control. Canaloplasty is described by the authors as “a nonperforating blebless technique derived from viscocanalostomy, in which a 10-0 prolene suture is positioned and tensioned within Schlemm’s canal, thus facilitating aqueous outflow through natural pathways (collectors channels and aqueous veins) and can only be performed if the Schlemms canal is open for the entire 360 degrees.” All five patients that had the procedure performed were followed up every six months; the mean reduction in IOP at two years was 15.9mmHg. The authors concluded that although canaloplasty is not normally considered after a failed trabeculectomy in selected cases in which Schlemms canal is intact canaloplasty could be considered.

Reference

Canaloplasty after failed trabeculectomy: a possible option.
Brusini P, Tosoni C.
JOURNAL OF GLAUCOMA
2014;23(1):33-4.

Journal of Glaucoma

Risk calculation variability over time in OHT
Reviewed by: Lorraine North
Vol 21 No1
 

In this study the authors aimed to assess the variability of the well documented risk model from the Ocular Hypertension Treatment Study (OHTS) that identified higher intraocular pressure (IOP), older age, lower central corneal thickness (CCT), greater vertical cup-to-disc ratio (VCDR), and worse pattern standard deviation (PSD) on visual field analysis as independent risk factors for the onset of primary open-angle glaucoma (POAG). They attempted to assess the variability of the OHTS glaucoma risk prediction model in OHT subjects by applying updated risk factor information obtained during follow-up and measuring the variability in the calculated risk over time not just at baseline. This was a prospective longitudinal study over 60 months of 27 patients (54 eyes). Their results showed that seven individuals converted to POAG during the follow-up. At baseline the mean risk of conversion was 14.0 (12%); over the course of follow-up in this study the mean calculated risk was 13.4 (10.7%). The authors showed that there were substantial fluctuations from visit to visit and that reliance on baseline characteristics assumes that risk of progression is linear. Further work is needed to define the frequency with which updated risk factors should be incorporated into prediction models.

Reference

Risk calculation variability over time in ocular hypertensive subjects.
Christian S, Gustavo DMC, Ilana F, et al.
JOURNAL OF GLAUCOMA
2014;23(1):1-4.

Journal of Pediatric Ophthalmology and Strabismus

Cyclo spray vs. drops
Reviewed by: Fiona Rowe
Vol 21 No1
 

The purpose of this study was to investigate whether cyclo spray is better tolerated than cyclo drops and to assess the adequacy of cycloplegia achieved by spray for objective refraction. Cyclo drops were given to 72 children and cyclo spray to 77 children. The mean age was 4.4 years in the drop group and 4.6 years in the spray group. There was no reduction in distress for children aged over seven years; 16.9% did not have adequate cycloplegia with the spray and this was mainly due to dark irides.

Reference

A prospective comparison between cyclopentolate spray and drops in paediatric out-patients.
Syrimi M, Jones SM, Thompson GM, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:290-5.

Journal of Pediatric Ophthalmology and Strabismus

DTI/MRI results in amblyopia
Reviewed by: Fiona Rowe
Vol 21 No1
 

Diffusion tensor imaging (DTI) is an MRI technique that can evaluate white matter integrity and neuronal connectivity. Normal brain maturation and myelination are associated with reduced water diffusion and increased diffusion anisotropy. The authors aimed to evaluate the anterior optic pathways with DTI in 10 children with unilateral amblyopia, five children with bilateral amblyopia and 10 control subjects. The mean age was 10.8±2.8 years for unilateral amblyopia, 11.5±1.5 years for bilateral amblyopia and 13.8±2.6 years for controls. In unilateral amblyopia eyes and fellow eyes, fractional anisotropy (FA) values were significantly reduced in prechiasmatic regions. Mean diffusivity (MD) values were greater than controls. In bilateral amblyopia, prechiasmatic FA values were lower but not significantly so. MD values were greater in all anatomic regions but were not significant. The findings may indicate a functional underdevelopment of the anterior visual pathways in patients with unilateral amblyopia affecting both eyes.

Reference

Anterior visual pathways in amblyopia: quantitative assessment with diffusion tensor imaging.
Gümüstas S, Altintas O, Anik Y, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:369-74

Journal of Pediatric Ophthalmology and Strabismus

Normal values with Orbscan IIz corneal topography
Reviewed by: Fiona Rowe
Vol 21 No1
 

This study aimed to establish a database of normative measurements of corneal typography in children aged 5-15 years with the Orbscan IIz corneal topography system. They assessed 100 eyes of 100 children. The mean SimK astigmatism was 0.69±0.35D. The maximum and minimum K values were 44.26±1.55 and 43.56±1.57D respectively. Anterior best fit sphere (ABFS) was 7.92±0.26mm and posterior best fit spheres (PBFS) was 6.46±0.24mm with a ratio of ABFS/PBFS of 1.23±0.02. The most common anterior and posterior corneal elevation pattern was the incomplete ridge. The thinnest site on the cornea had an average thickness of 540±34.03um, mostly in the inferotemporal quadrant.

Reference

Corneal typography and corneal thickness in children.
Reddy SP, Bansal R, Vaddavalli PK.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:304-10.

Journal of Pediatric Ophthalmology and Strabismus

Risk factor for surgical failure in consecutive XT
Reviewed by: Fiona Rowe
Vol 21 No1
 

This study was designed to determine the success rate among patients with consecutive exotropia after choosing an appropriate surgical method based on medial rectus function and level of exo deviation. The authors conducted an interventional case series study of 40 consecutive cases of exotropia. The mean deviation preoperatively was 29±13PD reducing to 7±7PD at a minimum three month follow-up. Surgical success at <8PD was achieved in 77.5% of cases: 83.3% with medial rectus resection, 81% with lateral rectus recession and 57.1% in combined surgery. The preoperative amount of exo deviation was the only risk factor of surgical failure in this study.

Reference

Surgical results of consecutive exotropia.
Rajavi Z, Feizi M, Mughadasifar H, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:274-81.

Journal of Pediatric Ophthalmology and Strabismus

Risk factors for consecutive XT
Reviewed by: Fiona Rowe
Vol 21 No1
 

The authors report a retrospective study to investigate possible risk factors leading to consecutive exotropia development in patients who underwent two muscle strabismus surgery to achieve an initial alignment within 10PD. The exotropia group included 25 female and 22 males. The non-exotropic group included 22 females and 32 males. Consecutive exotropia was present in 13% on the first postoperative day, 17% at first month and 40% by the end of the first six months. Risk factors included limited adduction, asymmetrical surgery, presence of amblyopia and anisometropia, although it was acknowledged that anisometropia may be linked with amblyopia.

Reference

Analysis of risk factors for consecutive exotropia and review of the literature.
Yurdakul NS, Ugurlu S.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:268-73.

Journal of Pediatric Ophthalmology and Strabismus

Risk factors for failed vision screening
Reviewed by: Fiona Rowe
Vol 21 No1
 

Failure rates on vision screening tests were reported by age and racial / ethnic categories in a large sample of children with most aged 6-11 years. Many children resided in lower socioeconomic status areas. Data was taken from 9743 children. Nine hundred and fifty-one children with glasses were significantly more likely to be older and white. Groups did not differ significantly for estimated income. Of 4253 children, 598 failed one or more vision screening tests. Age was significantly associated with failed tests, as was African-American and Hispanic status. Approximately 14% of African-American and Hispanic children failed at least one test compared to 11% of white children. There was a significant difference in screening failure rates based on age and ethnicity depending on the different tests used: far vision test, plus lens test, random dot E test and near point acuity. The 9-11 year children had the highest rate of fails.

Reference

Ocular problems in low income and minority children.
Frick DJ, Olitsky SE, Campbell A, Glaros AG.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:363-8.

Journal of Pediatric Ophthalmology and Strabismus

Risk factors for further surgery in consecutive ET
Reviewed by: Fiona Rowe
Vol 21 No1
 

he preoperative and postoperative factors around first surgery for exotropia were investigated for predicting second surgery for consecutive esotropia. Fifty-two patients with consecutive esotropia after exotropia surgery were reviewed: 17 required surgery for the esotropia and 35 did not. There was no significant intergroup difference for age at diagnosis, age at first surgery, preoperative exo deviation, refractive error, rate of lateral incomitance or strabismus deviation at one day, three months and six months postoperative. However, amounts of eso deviation at one month postoperative were higher in those requiring surgery.

Reference

Risk factors predicting the need for additional surgery in consecutive esotropia.
Choi YM, Lee JY, Jung JH, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:335-9.

Journal of Pediatric Ophthalmology and Strabismus

Strabismus in high myopia
Reviewed by: Fiona Rowe
Vol 21 No1
 

The authors report the occurrence of exotropia-hypotropia complex in 15 cases of high myopia. The mean age at presentation was 23.5 years (10-35 years). Only two patients had high bilateral myopia. The mean axial length of the deviating eye was significantly more than the fellow eye: 29.60±1.51mm versus 24.69 ±1.82mm. The mean preoperative angle was 37±9 exo and 13±6 hypo deviation. The position of the extra ocular muscles was interpreted reliably in 93% of cases by orbital imaging. There was no significant displacement found. Eight cases were managed with strabismus surgery and one was found to have a misplaced muscle insertion. No specific aetiological factors were found for this series.

Reference

Exotropia – hypotropia complex in high myopia.
Monga S, KeKunnaya R, Sachdeva V.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:340-6.

Neuro-Ophthalmology

An unusual case of sellar chondroma
Reviewed by: Claire Howard
Vol 21 No1
 

A single case of chondrogenic neoplasm arising from the base of the skull is presented and discussed. These benign and slow growing tumours in the sellar region are extremely rare and as such this article provides a useful insight and discussion for consideration. The article describes a 63-year-old man presenting with a long history of sexual dysfunction, bilateral vision loss and left nasal obstruction. Endocrine tests showed that all serum levels of anterior pituitary hormones were decreased. MRI imaging showed a large mass lesion in the saddle area, extending upwards to the dorsal sellae, bilateral cavernous sinus and suprasellar region and downwards into the sphenoid sinus and nasal cavity. The optic nerves and chaism were compressed giving a bilateral superior altitudinal visual field defect and reduced visual acuity in both eyes. This man had symptoms lasting for a six-year duration prior to diagnosis so this article highlights the need to recognise signs early to allow early detection and treatment. The patient was treated with hormone replacement and transfusion of plasma and albumin, as well as a two stage surgical procedure. Possible surgical approaches are discussed in detail in the article. The tumour was removed successfully and postoperatively the patient was stable and his visual acuity and visual field defect improved markedly. His pituitary function returned to normal except for hypothyroidism.

Reference

Giant chondroma of the saddle area: case report and literature review.
Qiu L, Zhu Y, Wang H, et al.
NEURO-OPHTHALMOLOGY
2013;37(6):231-8.

Neuro-Ophthalmology

An unusual case report of bilateral abducens paralysis
Reviewed by: Claire Howard
Vol 21 No1
 

In this case report a nine-year-old girl develops bilateral abducens nerve paralysis, caused by vertebrobasilar dolichoectasia. Vertebrobasilar dolichoectasia is characterised by dilation, tortuosity and marked elongation of the vertebral and basilar arteries. Clinical findings result from the compression and displacement of adjacent structures. In this unusual case the child presented with a longstanding large angle esotropia (with four-year history) with bilateral lateral rectus underaction. Magnetic resonance imaging (MRI) revealed compression of both abducens nerves and the pons. Magnetic resonance angiography (MRA) confirmed the dolichoectatic basilar artery. This is an interesting finding in a rare condition, with a manifestation not found to be previously reported in the literature. Often cases of dolichoectasia are asymptomatic. MRA investigations should be considered in cases of unilateral or bilateral nerve paralysis when there is no known cause.

Reference

Bilateral abducens paralysis secondary to compression of abducens nerve roots be vertebrobasilar dolichoectasia.
Ayhan Tuzcu E, Bayaroullari H, Coskun M, et al.
NEURO-OPHTHALMOLOGY
2013;37(6):254-6.

Neuro-Ophthalmology

Using frequency doubling technology perimetry to identify Alzheimer’s disease early
Reviewed by: Claire Howard
Vol 21 No1
 

Alzheimer’s disease is widely reported to be associated with deficits in visual function. Visual disturbances include impaired stereopsis, contrast sensitivity and motion detection. Deficits specific to the magnocellular pathway (MGC) have been identified in Alzheimer’s disease. This article compares the visual field performances of patients with mild Alzheimer’s disease with normal control subjects. The authors detected visual field impairment attributable to the magnocellular pathway using frequency doubling technology – Matrix (FDT-Matrix). The FDT Matrix perimetry is based on an illusion occurring when a grating of low spatial frequency undergoes counter-phase flicking and measures contrast sensitivity. The process selectively tests the function of the MGC pathway. The authors suggest that testing the response of the MGC pathway using this method may be a sensitive method of detecting a field defect. Patients with Alzheimer’s disease took significantly longer to perform the test than controls. There were statistically significant differences in mean deviation and pattern standard deviation values between the two groups. The results imply that the pathogenesis of cognitive decline may be present in the magnocellular pathway, as well as the cortical area, in Alzheimer’s disease. FDT testing may be a useful test for early identification of Alzheimer’s disease, as well
as for follow-up of these patients, especially when visual field testing is unreliable due to cognitive impairment. Further studies are required to further explore the source of visual field loss in
this patient group, as well as the clinical usefulness of FDT
testing.

Reference

Screening for patients with mild Alzheimer’s disease using frequency doubling technology perimetry.
Aykan U, Orcun Akdemir M, Yildirim O, Varlibas F.
NEURO-OPHTHALMOLOGY
2013;37(6):239-46.

Ophthalmology

Antibiotic prophylaxis after intravitreal injections
Reviewed by: Brian Ang
Vol 21 No1
 

The use of topical antibiotics as prophylaxis after intravitreal injections is a contentious issue, especially now with increasing use of intravitreal anti-VEGF agents. In the Wills Eye Institute, prior to May 2011, all patients undergoing intravitreal injections in the office setting routinely received post-injection topical antibiotics four times daily for four days. However, the practice of post-injection antibiotics was discontinued practice-wide from September 2011 onwards. Apart from the cessation of post-injection antibiotics, there were no other changes to the technique of preparing for and administering the injections (with a 30- or 31-gauge needle). Topical 5% povidone iodine was applied pre-injection, but sterile draping and eyelash preparation were not used. The authors retrospectively compared the incidence of endophthalmitis following intravitreal injections during and after the post-injection topical antibiotic period. During the 28-month post-injection topical antibiotic period studied, 57,654 injections were administered with 28 cases of suspected endophthalmitis (0.049%) and 10 culture-positive endophthalmitis (0.017%). During the nine month period when post-injection topical antibiotics were discontinued, 34,900 injections were administered with 11 cases of suspected endophthalmitis (0.032%) and four culture-positive endophthalmitis (0.011%). The difference in endophthalmitis rates between the two groups was not statistically significant. This is the largest reported series of intravitreal injections so far, and the results are very compelling in demonstrating that post-injection topical antibiotics do not reduce the risk of endophthalmitis and in fact may even increase the risk of endophthalmitis. The evidence is clear that there is no role for routine post-injection antibiotic prophylaxis.

Reference

The role of topical antibiotic prophylaxis to prevent endophthalmitis after intravitreal injection.
Storey P, Dollin M, Pitcher J, et al.
OPHTHALMOLOGY
2014;121:283-9.

Ophthalmology

Cost-effectiveness of femtosecond cataract surgery
Reviewed by: Brian Ang
Vol 21 No1
 

Femtosecond laser-assisted cataract surgery has become increasingly popular due to the reported benefits of increasing precision and reproducibility of capsulorrhexis, less power and manipulation required during phacoemulsification, better corneal wound architecture, and the ability to place precise arcuate keratotomy incisions if required. With these benefits, it is hoped that there will be improved visual acuity and refractive outcomes, as well as reduced incidence of intraoperative and postoperative complications. However, this technology comes at a cost premium. In this paper, the authors calculate the cost-effectiveness of femtosecond laser-assisted cataract surgery compared to normal phacoemulsification cataract surgery. Using a series of estimates and assumptions, including in the calculation of utility values and quality-adjusted life-years (QALY), the authors found that the cost-effectiveness of using femtosecond laser-assisted cataract surgery was $102,691 per QALY. When calculated relative to routine phacoemulsification cataract surgery, the cost per QALY for femtosecond laser-assisted cataract surgery was $92,862, indicating lack of cost-effectiveness. Femtosecond laser-assisted cataract surgery remained non-cost-effective even when modelling a best-case scenario with 100% visual outcomes, no complications, and at reduced cost to patients. The authors calculated that for cost-effectiveness to be achieved, the cost of femtosecond laser-assisted cataract surgery needs to decrease by at least 50% to 70%. Public hospitals are therefore unlikely to adopt this technology due to the high additional cost and marginal benefits over what is already a very safe and effective cataract surgery technique.

Reference

Cost-effectiveness of femtosecond laser-assisted cataract surgery versus phacoemulsification cataract surgery.
Abell RG, Vote BJ.
OPHTHALMOLOGY
2014;121:10-6.

Ophthalmology

Sutureless 27-gauge needle intrascleral intraocular lens implantation
Reviewed by: Brian Ang
Vol 21 No1
 

The authors report on a prospective, non-comparative, interventional case series of patients undergoing sutureless intrascleral fixation of a posterior chamber three piece intraocular lens (IOL) using a 27-gauge needle for docking. Sutureless techniques have the advantage of not having complex suture manoeuvres, suture-induced inflammation, suture degradation and delayed IOL dislocation from broken sutures. Using a 27-gauge needle has two advantages: the sclerostomy wound will be small enough to be self-sealing, and that the haptic can be docked into the needle and externalised with less risk of haptic damage. The authors also describe 50% thickness scleral cuts 1.5mm in length, parallel to the limbus, 1.7mm from the limbus. One end of the scleral cut is the site of the 27-gauge sclerostomy, and the other end is the start of the scleral tunnel within which the haptic is buried – having a distance of 1.5mm between the sclerostomy and the start of the scleral tunnel means that it is easier to grasp the externalised haptic and insert it into the tunnel. In this case series of 34 patients (average age 67.8 years), the best-corrected logMAR vision increased from 0.48 to 0.17 after three months. The commonest postoperative complications were iris capture (three eyes; 8.6%), transient ocular hypertension (two eyes; 5.7%), and cystoid macular oedema (one eye; 2.9%). In 15 cases, there was follow-up of greater than 12 months – in these cases there were no cases of IOL decentration or significant vision changes. Although this study is limited by its relatively small sample size and short follow-up duration, the results suggest that this is a useful and technically simple technique for sutureless intrascleral IOL implantation in eyes without capsular support.

Reference

Sutureless 27-gauge needle-guided intrascleral intraocular lens implantation with lamellar scleral dissection.
Yamane S, Inoue M, Arakawa A, Kadonosono K.
OPHTHALMOLOGY
2014;121:61-6.

Strabismus

Fusion amplitude with Bagolini glasses
Reviewed by: Fiona Rowe
Vol 21 No1
 

The aim of this study was to determine whether there is a difference between the horizontal prism fusion amplitude measured with and without the Bagolini striated glasses (BSG) in 52 young adults. Subjects had a mean age of 21.06 years, 13.5% were male, 30 were exophoric and seven esophoric. Right eye dominance was present in 36 and left eye dominance in 16 subjects. The results showed significantly smaller fusional ranges obtained with BSG during measurements at near fixation. No differences were found with / without BSG at distance. Ocular dominance had no effect. BSG affects results with altered natural viewing conditions.

Reference

Bagolini glasses: do they affect the horizontal prism fusion amplitude?
Schultinga L, Burggraaf F, Polling JR, Gutter M.
STRABISMUS
2013;21:127-30.

Strabismus

Management of high AC/A esotropia
Reviewed by: Fiona Rowe
Vol 21 No1
 

The purpose of this study was to determine the long-term effect of treating high accommodative convergence to accommodation (AC/A) esotropia with single vision lenses (SVL) compared with the effectiveness of using SVL on patients with basic refractive esotropia and a normal AC/A ratio. The authors identified 23 patients with high AC/A esotropia and 14 patients with refractive esotropia. Patients with high AC/A ratio showed high improvement and low deterioration rates, suggesting SVL is an effective form of treatment for high AC/A esotropia. Average hypermetropia was significantly higher in patients with refractive esotropia than AC/A esotropia. No patients were weaned out of glasses during the study. Each group had a significant decrease in size of deviation at near fixation after five years of treatment with SVL. Control of deviation at near fixation improved in both groups over the follow-up period but this was significantly better in the refractive group than the AC/A group. The AC/A group had significantly increased stereopsis but there was better stereopsis in the refractive group at five years follow-up. The authors found that using SVL to treat high AC/A esotropia did not have a negative impact on the
development of stereopsis and propose SVL as an acceptable form of treatment.

Reference

Single-vision lenses: a comparison of management of high AC/A esotropia and refractive esotropia.
Gerling A, Arnoldi K.
STRABISMUS
2013;21:106-9.

Strabismus

Ocular findings in autism
Reviewed by: Fiona Rowe
Vol 21 No1
 

This retrospective study investigated the ocular manifestations of autistic spectrum disorders (ASD) among children in a paediatric ophthalmic practice setting. Fifty-three patients were identified. Assessments were undertaken for 44 with 68% having autistic disorder, 16% with pervasive personality disorder – not otherwise specified – and 16% with Asperger’s syndrome. Male:female ratio was 3:1. Ocular abnormalities were found in 52%. Strabismus was present in 41%, significant refractive error in 27%, anisometropia in 7% and amblyopia in 11%. The percentage of ocular abnormalities was higher than that in the general population

Reference

Ocular manifestations of autism in ophthalmology.
Black K, McCarus C, Collins MLZ, Jensen A.
STRABISMUS
2013;21:98-102.

Strabismus

Ocular neuromyotonia
Reviewed by: Fiona Rowe
Vol 21 No1
 

The authors report a cohort of ten patients (nine female) with ocular neuromyotonia (ONM) for clinical signs and symptoms, treatment methods and outcome. Six had affected vertical muscles including superior oblique, inferior rectus and superior rectus. Four had affected lateral rectus muscles. Episodes were predominantly every 10-40 minutes and lasting from a few seconds to minutes. Episodes were repeated and recurrent throughout the day. Two cases had previous cranial radiation, two had thyroid eye disease and one had superior oblique myokymia that progressed to ONM. Treatment was typically with carbamazepine or Gabapentin.

Reference

Ocular neuromyotonia: differential diagnosis and treatment.
Roper-Hall G, Chung SM, Cruz OA.
STRABISMUS
2013;21:131-6.

Strabismus

Stereopsis changes with cataract
Reviewed by: Fiona Rowe
Vol 21 No1
 

Stereoacuity was compared preoperatively to six weeks postoperative after cataract extraction and intraocular lens (IOL) implant. The authors evaluated the association of postoperative stereoacuity with visual acuity, age and duration of preoperative symptoms. This prospective study recruited 142 patients: 92
male and 50 female. Stereoacuity was measured in 30% preoperatively and 99% postoperatively, which was significant at p=0.0001. Increase in age was associated with reduced stereoacuity. There was no significant correlation of stereoacuity and duration of symptoms. Postoperative stereoacuity was correlated with postoperative visual acuity in the better eye. No correlation was found for stereoacuity and inter-ocular visual acuity difference.

Reference

Effect of bilateral age-related cataract on stereoacuity.
Manoranjan A, Shrestha S, Shrestha S.
STRABISMUS
2013;21:116-22.

Strabismus

Strabismus in bilateral pseudo-aphakes
Reviewed by: Fiona Rowe
Vol 21 No1
 

The authors evaluated ocular deviation and near stereopsis for five years after bilateral cataract surgery in 88 patients. The results showed that patients with preoperative near exophoria angle greater than 12PD progressed more rapidly to intermittent exotropia after surgery with reduced near stereopsis. Ocular changes occurred in the first two postoperative years and thereafter the ocular deviation increased back towards preoperative values. The authors suggest patients with near exophoria greater than 12PD require long-term follow-up.

Reference

Five-year follow-up of ocular deviation in bilaterally pseudo-aphakic patients.
Hoshikawa R, Ito M, Shimizu K, et al.
STRABISMUS
2013;21:110-5.

Journal of Glaucoma

RAPD in glaucoma screening
Reviewed by: Lorraine North
Vol 21 No1
 

A study was conducted to investigate the relative afferent pupillary defect (RAPD) by swinging flashlight as a potentially useful screening test for glaucomatous optic neuropathy. The authors recruited 107 subjects with or without glaucoma from a clinic population. A medical student with no prior ophthalmology experience was trained to test for RAPD using neutral density filters by a neuroophthalmologist. The student performed this masked study on all subjects and those that showed no RAPD then had the swinging light test repeated with 0.3, 0.6 and 0.9 neutral density filters. A result was deemed positive if the neutral density filter in front of the two eyes with subsequent RAPD testing resulted in an asymmetric pupillary response only when the filter was placed in front of one of the two eyes, but not the other. The medical charts were then reviewed to determine the absence or presence of glaucoma. Subgroup analysis was then performed on 67 subjects who had previously undergone cataract surgery. The authors report that RAPD with neutral density filters demonstrated a sensitivity and specificity of 66.7% and 82.9%, respectively, for all subjects and 68.8% and 88.6%, respectively, for those who had not previously undergone cataract surgery when used to screen for glaucomatous disease. A higher negative predictive value was, however, seen in the subgroup that had undergone cataract surgery. The authors recognised a number of limitations with the study, including clinic setting, personnel performing the test and the test was not deemed suitable for mild or advanced disease. However, this test combined with a number of other screening tests could be performed by a non-ophthalmologist making them useful screening tools.

Reference

Glaucoma screening using relative afferent pupillary defect.
Charalel RA, Lin HS, Singh K.
JOURNAL OF GLAUCOMA
2014;23(3):169-73.

Journal of Glaucoma

SLT short-term results
Reviewed by: Lorraine North
Vol 21 No1
 

The aim of the study was to evaluate the risk of adverse effects and short-term results after 360 degrees selective laser trabeculoplasty (SLT) in glaucoma patients. The authors enrolled 64 eyes of 64 patients all who had poorly controlled primary open-angle glaucoma (POAG) by medical treatment. Patients were assessed for inflammation in the anterior chamber, inflammatory signs in the vitreous and retina intraocular pressure (IOP), both before and after SLT at 24hrs, 14 days, six weeks and three months after laser. The retinal thickness was assessed using spectralis OCT. All SLT procedures were performed by the same experienced surgeon and grading of inflammation, IOP measurement and OCT scanning were conducted by another examiner independently. All patients were treated with SLT for the first time and the authors showed a statistically significant reduction in mean IOP at each interval. There was no statistically significant increase in mean retinal thickness and there were no clinically relevant signs of inflammation in the anterior chamber or vitreous. The authors’ results showed that 360 degree SLT treatment produced no clinically relevant inflammation and the authors did not use any pre or postoperative medications which they believe is the first study to investigate this. Limitations of the study include the missing of post treatment IOP spikes within the first 24hrs. The authors conclude that further similar studies need to be conducted in patients with pseudoexfoliation or pigmentary glaucoma following SLT.

Reference

Adverse effects and short-term results after selective laser trabeculoplasty.
Klamann MKJ, Maier A-K B, Gonnermann J, Ruokonen PC.
JOURNAL OF GLAUCOMA
2014;23(2):105-8.

Strabismus

Extraocular muscle BT after ocular pathology
Reviewed by: Fiona Rowe
Vol 21 No1
 

Management is described for 13 patients who received inferior rectus botulinum toxin (BT) injection for vertical strabismus due to orbital pathology. Patients were aged 19-86 years, eight were female and seven were right eye injections. Orbital pathology included six with idiopathic orbital inflammatory syndrome, three with orbital wall fracture, one optic nerve sheath schwannoma post resection, one lymphoma and one spontaneous superior ophthalmic vein haemorrhage. Each patient had diplopia. Benefit from BT was noted in nine (69%). Follow-up was from three months to three years. A functional cure was achieved in five (38%) with a single BT dose. Benefit was independent on the angle of deviation.

Reference

Role of inferior rectus botulinum toxin injection in vertical strabismus results from orbital pathology.
Bunting HJ, Dawson ELM, Lee JP, Adams GGW.
STRABISMUS
2013;21:165-8.

Acta Ophthalmologica

Exudative age-related macular degeneration
Reviewed by: Nana Theodorou
Vol 20 No 6
 

The authors looked at macular lesions in eyes with newly diagnosed exudative age-related macular degeneration. The eyes of 23 patients were included and tested for visual acuity, contrast sensitivity, microperimetry, optical coherence tomography (OCT) and fluorescein and indocyanine green angiography. The findings indicated decreased retinal sensitivity correlated significantly with the presence of choroidal neovascularisation, haemorrhage, subretinal tissue and retinal pigment epithelium elevation. The most important OCT parameter was the thickness of the retinal pigment epithelium elevation.

Reference

Correlation between components of newly diagnosed exudative age-related macular degeneration lesion and focal retinal sensitivity.
Hautamaki AH, Oikkonen J, Onkamo, et al.
ACTA OPHTHALMOLOGICA
2014;92:51-8.

Acta Ophthalmologica

Retinopathy of prematurity
Reviewed by: Nana Theodorou
Vol 20 No 6
 

This review article describes the pathophysiology of retinopathy of prematurity (ROP). The authors start by introducing the condition and its incidence. There is extensive information on the pathophysiology mechanisms involved in the condition to include normal and pathological retinal development. The first and second phases of ROP are described and the role of growth factors is discussed. There is a section for the genetic component of ROP and discussion on recent study findings to understand the factors that contribute to its aetiology and management. The article provides a good overview of the condition to include evidence from recent studies.

Reference

The pathophysiology of retinopathy of prematurity: an update of previous and recent knowledge.
Cavallaro G, Filippi PB, Bagnoli P, et al.
ACTA OPHTHALMOLOGICA
2014;92:2-20.

British Journal of Ophthalmology

DISC lens slow myopia progression in Hong Kong Chinese schoolchildren
Reviewed by: Jonathen Chan
Vol 20 No 6
 

This is a prospective double-blind randomised trial between September 2007 and October 2009. It included 221 children aged 8-13 years, with myopia between -1 and -5 Dioptres ≤1.00D. There were 111 patients in the defocus incorporated soft contact DISC group and 110 in the single vision (SV) contact lens group. The DISC contact lens is a custom-made bifocal soft contact lens of concentric rings design. It comprised a correction zone in the centre and a series of alternating defocusing and correction zones extending towards the periphery having a proportion of 50:50. The correcting zones matched the distant prescription while the defocusing zones were 2.5D relatively negative. Such design allowed to introduce myopic retinal defocus and to maintain clear vision, simultaneously. The single vision lenses were made using the same material with matching parameters without any defocusing zones. The contact lens fitting was performed according to the cycloplegic refraction, corneal curvature and horizontal visible iris diameter. All the patients were measured including the refractive error and axial length at six monthly intervals. The differences between groups were analysed using unpaired t test. One hundred and twenty-eight children completed this study, 65 in the DISC group and 63 in the SV group. It was found that myopia progressed 25% more slowly for children in the DISC group compared to those in the controlled group (0.3 D per year, 95% CI -0.1 to -0.47 v 0.4 D spheres per year; 95% CI -0.93 to -0.65, p=0.031). In addition it was found that the axial length elongation was less in the DISC group compared to the SV group (0.1mm/year comparing 0.18mm/year in the SV group). The effect of the wearing time further increased to 58% when the children had worn the DISC lenses for seven hours per day or more. The marginal benefit from the increased wearing time was smaller when the wearing time reached eight hours. It was found that myopia in children who wore the DISC lenses for five or more hours per day progressed 46% less than those in the SV group. The authors commented that the major limitation was that there was a high dropout rate (approximately 42%); 3/4 dropped out in the first year. The main reason for both groups was lack of motivation in contact wear. The authors conclude that daily wearing of the DISC lenses significantly slowed myopia progression and axial length elongation in Hong Kong schoolchildren. The findings also show that simultaneous clear vision with constant myopic defocus can retard myopia progression.

Reference

Defocus Incorporated Soft Contact (DISC) lens slow myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial.
Lam CSY, Tang WC, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:40-5.

British Journal of Ophthalmology

Intracameral bevacizumab as an adjunct to trabeculectomy
Reviewed by: Jonathen Chan
Vol 20 No 6
 

This is a 12-month, prospective, randomised, double-masked, placebo-controlled trial of patients who were not controlled medically with open angle glaucoma and scheduled for a primary trabeculectomy. Patients were recruited and randomised during the period between April 2009 and November 2010. In the study group patients received 50µL of either bevacizumab (1.25mg) or placebo balanced salt solution (BSS) peroperatively. The success was defined as intraocular pressure (IOP) ≤18mmHg and >5mmHg with at least 30% reduction from baseline and no loss of light perception. There were 138 patients who completed a 12-month follow-up cycle and of those 69 were in the bevacizumab treated group. The intraocular pressures were measured at one year postoperatively and found to be significantly lower than baseline (placebo: 25.6±9.9mmHg vs. 11.5 ≤3.9mmHg, p<0.01; bevacizumab: 24.8±8.1mmHg vs. 11.9±3.8mmHg, p<0.01) with no difference between treatment groups (p=0.69). It was found that the absolute success was higher in the bevacizumab group (71% vs. 51%) with the need for lowering of the intraocular pressure interventions (needlings) being lower in this group (12% vs 33%). The surgical technique used was by injecting either the study medication (50µL bevacizumab at a concentration of 25mg/mL) or placebo (BSS) solution intracamerally through the paracenteses using a single-use 30-gauge needle. At the end of the procedure, a subconjunctival injection of betamethasone was administered. Topical preparations containing tobramycin and dexamethasone were used as an ointment and then continued four times a day for eight weeks duration. The authors commented that the limitation of this study concerns the inclusion of patients scheduled for trabeculectomy with or without mitomycin C (MMC) use. The authors commented that the standard at the centre for patients without risk of scarring involved the use of MMC only if a low target pressure was deemed necessary. A post-hoc analysis revealed that despite no significant differences in the primary outcome at the 12-month period, bevacizumab could still significantly improve the survival curve in both subgroups (with or without MMC use). The authors concluded that intracameral bevacizumab significantly reduces the need for additional interventions during the follow-up of patients undergoing primary trabeculectomy procedure.

Reference

Intracameral bevacizumab as an adjunct to trabeculectomy: a 1-year prospective, randomised study.
Vandewalle E, Pinto LA, Van Bergen T, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2014;98:73-8.

Clinical and Experimental Ophthalmology

Direct endoscopic probing for congenital lacrimal duct obstruction
Reviewed by: Dr Anjali Gupta
Vol 20 No 6
 

The most common treatment for congenital lacrimal duct obstruction (CLDO) is probing, which is traditionally a blind procedure. Previous literature reports success rates between 78-92%. The authors of this retrospective non comparative case series reviewed the success rates of probing with dacryoendoscopy, which enables simultaneous probing with visualisation of the site of obstruction. Ten patients (13 lacrimal ducts) over the age of one year (mean age 40.7 months, range 14-74 months) diagnosed with CLDO who underwent direct endoscopic probing with dacryoendoscopy under general anaesthesia were included in this study. The dacryoendoscope was inserted into the lacrimal drainage system via the punctum. Once the site of obstruction was seen, the endoscope was advanced to perforate the obstructed area. Telephone interviews were performed six months after the surgery to assess the subjective outcome of the procedure. Disappearance of epiphora was reported in 12/13 (92.3%) cases. However, 5/13 (38.5%) reported occasional discharge from the eye. Two of the 13 cases had undergone previous unsuccessful blind probing, one of these two cases had subsequent successful direct endoscopic probing, the other had persistent epiphora. Various sites of obstruction were noted; the most common were the nasolacrimal duct (7/13), Valve of Hasner (2/13), lacrimal sac (2/13) and the canaliculus (2/13). Two of the 13 cases had more than one site of obstruction. No obstruction was seen in one patient but a hypertrophic mucous membrane was noticed and probing had resulted in disappearance of epiphora. There were no complications from intraoperative endoscopy or general anaesthesia. The authors conclude that probing with dacryoendoscopy is a safe and effective treatment method for CLDO but are aware that their conclusions are limited by the small number of cases studied.

Reference

Direct endoscopic probing for congenital lacrimal duct obstruction.
Sasaki H, Takano T, Murakami A.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

Clinical and Experimental Ophthalmology

PERG as a visual prognosticator in chiasmatic tumours
Reviewed by: Dr Anjali Gupta
Vol 20 No 6
 

Pattern electroretinogram (PERG) allows assessment of ganglion cell function and may therefore be used to assess anterior visual pathway dysfunction. This prospective non-randomised study assessed PERG before and after surgical removal of tumours in and around the sellar region compressing the anterior visual pathways in order to assess its utility as a prognostic tool. Best corrected visual acuity (BCVA), Humphrey visual field (VF) (30-2) and PERG were recorded one week preoperatively, one week and six weeks postoperatively. During PERG, the first negative wave (N1), the first prominent positive wave (P1/P50) and the second large negative wave (N2/N95) were recorded to calculate the N2/P1 ratio. ≥1.1 was taken to be normal and <1.1 was abnormal. Twenty patients (40 eyes) were included. Thirty-one eyes (77.5%) had a normal N2/P1 ratio preoperatively. This increased to 34 eyes (85%) in the early postoperative period and 35 eyes (87.5%) in the late postoperative period. There was no association between PERG and BCVA in the pre and postoperative periods (P=0.369). Of eyes with normal N2/P1 ratio, 47.1% showed an improvement in BCVA, compared to 50% eyes with abnormal N2/P1 ratio. There was also no significant association between PERG and VF pre and postoperatively (P=0.093). Of eyes with a normal N2/P1 ratio, 35.4% showed an improvement in VF postoperatively compared to 22.2% eyes with abnormal N2/P1 ratio. Of eyes with a normal N2/P1, 45.2% showed no change in VF postoperatively compared to 66% with an abnormal ratio. In conclusion, PERG is unlikely to be a useful prognosticator in the preoperative assessment of chiasmatic tumours, as an abnormal N2/P1 ratio is not associated with lesser or no clinical improvement post surgery when compared with a normal N2/P1 ratio.

Reference

Evaluation of pattern ERG as a visual prognosticator in chiasmatic tumours.
Goyal JL, Thangkhiew L, Yadava U, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2013;41:864-9.

Current Eye Research

A relationship between central serous retinopathy and obstructive sleep apnoea
Reviewed by: Dr Khadijah Basheer
Vol 20 No 6
 

This prospective study aimed to evaluate a relationship between central serous retinopathy (CSR) and obstructive sleep apnoea (OSA). Twenty-three subjects (six female and 17 male) were diagnosed with CSR and overnight polysonography was performed to record desaturation and apnoeic episodes. They found that 60% of patients had some form of OSA (mild, moderate, severe). Both CSR and OSA were seen more frequently in the male subjects and there is known to be a male predominance for both these conditions. The mechanism for this relationship is unknown but the authors suggest that it could result from oxidative stress. OSA is a sleep related disorder where repetitive obstruction of airflow in the upper airway leads to chronic recurrent hypoxia and oxidative stress. They hypothesise two mechanisms that connect the two conditions, the first being that oxidative stress causes choroidal vasoconstriction. Previous studies have shown choroidal circulatory disturbance with indocyanine green angiography in patients with CSR. The second mechanism is increased blood coagulation abnormalities as other studies have shown that levels of plasma activator inhibitor 1 (PAI-1) were increased in patients with both CSR and OSA. OSA is also associated with other ocular conditions such as normal tension glaucoma and also increases the risk of cardiovascular and neuropsychological diseases. If this relationship can be confirmed with further prospective studies, patients presenting with CSR should be screened for OSA and a thorough systemic history should be undertaken.

Reference

Obstructive sleep apnoea in patients with central serous chorioretinopathy.
Yavas GF, Kusbeci T, Kasikci M, et al.
CURRENT EYE RESEARCH
2014;39(1):88-92.

Current Eye Research

Macular slippage following macular hole surgery
Reviewed by: Dr Khadijah Basheer
Vol 20 No 6
 

The treatment of macular holes now involves peeling the internal limiting membrane (ILM) as well as vitrectomy and gas tamponade. It has been noted in previous studies that following an ILM peel the morphology of the macula is different. Tadayoni et al. noted numerous arcuate retinal striae along optic nerve fibres and called it ‘dissociated optic nerve fibre layer’ (DONFL). Optical coherence tomography (OCT) has shown that shallow dimples in the optic nerve fibre layer caused the appearance of DONFL. In addition, the temporal retina was found to be significantly thinner, whilst the nasal side was thicker than that in the fellow eye. This asymmetrical parafoveal retinal thickness was thought also to be caused by ILM peeling. This retrospective case study included 27 eyes that underwent macular hole surgery with vitrectomy and ILM peel and analysed the foveal to disc diameter before and after surgery. In addition, OCT images of the macula were also compared before surgery, early postoperatively and 12 months postoperatively. In all eyes included in the study all the post-operative foveal to disc diameters were shorter than preoperative measures. In particular this distance reduced most significantly in those eyes that showed characteristics of DONFL (78%). They conclude that the macula can slip towards the optic disc after ILM peel for macular hole surgery and that DONFL appearances can be seen between 6 to 18 months postoperatively. However, this was a small retrospective case study and it is unclear what clinical impact this may have, as there was no investigation into whether the patients were symptomatic from these changes. Although the anatomical changes are important to note for future fundus examinations in these patients, more research in a larger number of patients should be conducted to determine whether DONFL changes cause any new visual disturbances.

Reference

Macular slippage after macular hole surgery with internal limiting membrane peeling.
Nakagomi T, Goto T, Tateno Y, et al.
CURRENT EYE RESEARCH
2013;38(12):1255-60.

Experimental Eye Research

Autophagy in lens mitochondria loss
Reviewed by: Graham Wallace
Vol 20 No 6
 

The lens consists of a monolayer of epithelial cells that overlies fibre cells that differentiate from epithelial cells at the equator. While developing, fibre cells need mitochondria to provide energy, as they mature they lose these and other organelles to increase transparency and passage of light. Lens epithelial cells maintain mitochondria and supply nutrients and maintain lens homeostasis. Proteosomal and DNA degradation have been shown to have a role to play in organelle loss in fibre cells, but these are not the only mechanisms. Autophagy is a process whether cellular proteins and organelles can be enclosed in phagolysosomes leading to destruction. Degradation of mitochondria specifically is termed mitophagy. Whether autophagy is involved in organelle degradation in the lens is unclear with reports both supporting and refuting this mechanism. In this study, Costello et al. used electron microscopy and dual-label confocal microscopy to demonstrate the presence of autophagic vesicles containing mitochondria in lens epithelial and fibre cells. In support of this serum starvation, a common protocol to induced autophagy, led to mitophagy in primary lens epithelial cells. To date, loss of crystalline activity in clearance of aggregated proteins has been linked to cataract development. Now the autophagy pathway should be included in future studies.

Reference

Autophagy and mitophagy participate in lens organelle degradation.
Costello MJ, Brennan LA, Basu S, et al.
EXPERIMENTAL EYE RESEARCH
2013;116:141-50.

Experimental Eye Research

New mouse model of diabetes mellitus
Reviewed by: Graham Wallace
Vol 20 No 6
 

Diabetic retinopathy (DR) is a serious complication of diabetes. It is driven by the loss of pericytes, cells which control vascular function, due to excess formation of sugar alcohols by the enzyme aldose reductase (AR). AR has been shown to be present in pericytes in retinal capillaries in human and animal studies. Several animal models for DR have been described including dogs, rats and mice. However, the pathways and concentrations of AR activity and production of sugars appears to differ between species. While AR inhibitors were effective in dogs they had only minor benefits in humans. Moreover, accumulation of retinal sugars in streptozotocin-induced diabetic rats was significantly higher than in diabetic mice. Therefore, new model systems in mice with lower AR activity are required. In this paper transgenic mice were produced expressing human AR and green fluorescent protein under the control of the α-smooth muscle actin promoter (SMAA-GFP-hAR). Diabetes was induced by crossing these mice to the naturally diabetic C57BL/6-Ins2Akita/J mice (AK-SMAA-GFP-AR). The results showed that sorbitola levels measured by HPLC were higher in diabetic mice compared to controls. AK-SMAA-GFP-AR mice showed induction of VEGF, IGF-1, bFGF and TGFβ, all vascular angiogenic factors, as well as complementary signalling molecules. A significant increase in acellular capillaries was also seen compared to control mice. The development of this model has several advantages over current animal studies. Manipulating mouse genomes is significantly more advanced than in rats and more antibodies available for analysis. Moreover mice are substantially cheaper to breed and maintain than rats and dogs. The potential for this mouse model to be used in testing new AR inhibitors or other drugs is an obvious benefit of this study.

Reference

Novel transgenic mouse models develop retinal changes associated with early diabetic retinopathy similar to those observed in rats with diabetes mellitus.
Gou C, Zhang Z, Zhang P, et al.
EXPERIMENTAL EYE RESEARCH
2014;119:77-89.

Eye

Long-term outcomes following surgery for traumatic cyclodialysis clefts
Reviewed by: Nana Theodorou
Vol 20 No 6
 

This retrospective case series evaluated the long-term visual prognosis and intraocular pressure control following surgical treatment of traumatic cyclodialysis clefts. Cyclodialysis clefts result from the disinsertion of the longitudinal ciliary muscle fibres from the scleral spur and occur as a result of blunt ocular trauma or anterior segment surgery. Clinical data from 17 eyes was included for patients who underwent indirect and / or direct surgical cycloplexy. All eyes had ocular hypotony with optic disc swelling, macular folds or macular oedema. The main outcome measures included intraocular pressure (IOP), best-corrected visual acuity and the occurrence of postoperative complications. Mean age of the patients was 42 years with 16 men and one woman. Preoperatively, the mean IOP was 6.9mmHg (range, 2-14 mmHg) and postoperatively IOP was up to 70mmHg in 13 eyes. The final mean postoperative IOP was 12.2mmHg with no cases of secondary glaucoma or other serious complications. Preoperatively, best corrected visual acuity was 6/12 or better in 24% eyes, which rose to 71% at the final follow-up. The authors conclude that cyclodialysis clefts can be successfully corrected with direct surgical cycloplexy and / or cleft cryotherapy.

Reference

Long-term outcomes following the surgical repair of traumatic cyclodialysis clefts.
Agrawal P, Shah P.
EYE
2013; 27:1347-52.

Eye

Pain score assessment in babies undergoing treatment for ROP
Reviewed by: Nana Theodorou
Vol 20 No 6
 

The aim of this study was to assess neonatal pain scores during laser treatment for retinopathy of prematurity (ROP) under sub-tenon anaesthetic with oral or rectal sedation. Sixty-two babies were included who have had ROP laser treatment over a seven year period. Pain scores were assessed using the Neonatal Pain Agitation and Sedation Scale (N-PASS) every 10 minutes during laser treatment. The outcome and requirement for re-treatment in this group was compared with that in the intravenous sedation group. Pain scores were available in 19 of the 27 babies treated under sub-tenon anaesthesia. The mean pain score during treatment was 2.7 (SD±1.7, range 0.5–6.2). There was no statistically significant correlation between the mean pain score and duration of treatment, number of laser burns, or post-menstrual age of the baby at the time of treatment. Both treatments were equally successful irrespective of the sedation method. The mean pain scores during laser treatment under sub-tenon anaesthesia were lower than those previously reported during ROP screening or heel-stick procedure. This study supports that sub-tenon anaesthesia with oral or rectal sedation provides sufficient pain control for laser treatment for ROP without the need or risks of intravenous sedation and intubation.

Reference

Pain score assessment in babies undergoing laser treatment for retinopathy of prematurity under sub-tenon anaesthesia.
Novitskaya ES, Kostakis V, Broster SC, et al.
EYE
2013;7:1405-10.

Investigative Ophthalmology & Visual Science

Improved vision with perceptual learning
Reviewed by: Carmel Noonan
Vol 20 No 6
 

This study examined whether the development of crowded near visual acuity can be stimulated and whether crowding effects can be reduced by perceptual learning. The authors compared a magnifier crowded task with a perceptual learning crowded task and perceptual learning uncrowded task in 45 children with visual impairment and 29 children with normal vision. Children with visual impairment showed higher baseline crowding ratios than children with normal vision. Results showed improvement of single near visual acuity for all training groups. The crowded perceptual learning group showed the largest improvement in near visual acuity after training.

Reference

Perceptual learning in children with visual impairment improves near visual acuity.
Huurneman B, Boonstra FN, Cox RFA, et al.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
2013;54:6208-16.

Investigative Ophthalmology & Visual Science

Vision measurements vs. self-rating
Reviewed by: Carmel Noonan
Vol 20 No 6
 

The aim of this study was to evaluate the association between self-rated vision status and tests of visual acuity, contrast sensitivity, stereoacuity, bilateral visual field and self-reported visual function in specific domains of near and far vision. The goal was to determine which variables are most important when subjects rate the quality of their vision. The study sample was 2467 people. They found that multiple components are related to the simple measure of self-rated vision status. Better visual acuity, contrast sensitivity and bilateral visual fields and stereoacuity are associated significantly with better vision status. Better distance visual acuity and contrast sensitivity were most important in increasing odds of better vision status. Analysis of ADVS subscales revealed that better function on near and far vision subscales were significantly associated with better reports of vision status but particularly near vision.

Reference

Associations between self-rated vision score, vision tests and self-reported visual function in the Salisbury Eye Evaluation Study.
El-Gasim M, Munoz B, West SK, Scott AW.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
2013;54:6439-45.

Journal of Glaucoma

Arterial stiffness and PEX
Reviewed by: Lorraine North
Vol 20 No 6
 

The authors describe a study of 25 newly diagnosed patients with pseudoexfoliation glaucoma (PEX) and 25 controls to evaluate carotid femoral pulse wave velocity (CF-PWV) values. The CF-PWV was assessed using a noninvasive device by measuring the pulse transmit time and the distance between two recording sites conducted by a single experienced cardiologist. The study showed that patients with PEX had higher CF-PWV than did healthy individuals despite any difference between other factors such as body mass index (BMI), blood pressure (BP) and total cholesterol that are also predictors of cardiovascular diseases. The authors found an association between PEX and increased arterial stiffness which they felt may be attributed to the accumulation of pseudoexfoliative fibrils in the arterial wall. They report that this could aid diagnosis when in doubt about PEX and could be considered a risk factor for the development of PEX glaucoma.

Reference

Systemic arterial stiffness in patients with pseudoexfoliation glaucoma.
Türkyılmaz K, Oner V, Yüksel C, et al.
JOURNAL OF GLAUCOMA
2014;23(2):108-11.

Journal of Glaucoma

High myopes with POAG and IOP fluctuations
Reviewed by: Lorraine North
Vol 20 No 6
 

The authors describe a prospective study of 80 eyes of Chinese patients with primary open-angle glaucoma (POAG) on prostaglandin analogues to investigate if those who also have high myopia exhibit greater short-term intraocular pressure (IOP) fluctuations at resting conditions over 24 hours and after dynamic exercise. The authors used two protocols for IOP measurement by the same technician. Protocol 1 required all patients to be hospitalised and asked to maintain a supine position for 15 months before the start of the test; measurements were then taken at 8am, 10am, 2pm, 6pm, 10pm, 2am and 6am using pneumatonometer in the sitting position. Protocol 2 examined the IOP after dynamic exercise on the patients after a three day break from protocol 1. IOP was measured using Goldmann applanation tonometry. Their results showed that there was no difference between 24 hour fluctuations at resting conditions for both groups. However, they found a significant IOP fluctuation in patients with POAG and high myopia and the exercise test but the IOP decreased in this group particularly after rapid running compared to other POAG patients. The authors acknowledged the limitation in this study as IOP was measured in protocol 1 using a noncontact pneumatonometer which is not as accurate as Goldman tonometry.

Reference

Intraocular pressure fluctuations in patients with primary open-angle glaucoma combined with high myopia.
Yang Y, Li Z, Wang N, et al.
JOURNAL OF GLAUCOMA
2014;23(1):19-22.

Journal of Glaucoma

Macular thickness and visual fields
Reviewed by: Lorraine North
Vol 20 No 6
 

The authors describe a comparison of spectral domain OCT with Humphrey visual fields (HVF) mean deviation (MD) and pattern standard deviation (PSD), examining the retinal thickness of the macula and circumpapillary retinal nerve fibre layer (RNFL) defects. Seventy-three subjects who met the study criteria were analysed retrospectively. Patients were either diagnosed with glaucoma or glaucoma suspects. Both eyes were included and were analysed separately. The total average macular thickness plus the average macular thickness in superior and inferior macular halves as well as differences in total and macular half-thickness between the right and left eyes were examined. The average thicknesses of the circumpapillary RNFL in the superotemporal and inferotemporal quadrants for each eye were also recorded. MD and PSD HVF parameters were included and asymmetry between the eyes. The cup-to-disc (CD) ratio was also recorded. Correlations were determined using linear regression analysis. The authors found that eyes with a total macular thickness of <270 microns were significantly more likely to be associated with visual field loss by both MD and PSD. Whereas eyes with a total thickness of >300 microns were less likely to be associated with visual field losses. Also, when comparing the two eyes to each other or the superior macular to the inferior macular the visual field loss was associated to the thinner retina or retinal half. The authors demonstrated a strong correlation between RNFL and macular thickness measurements in glaucoma and showed how measurement of both the RNFL and macular thickness could provide useful additional information in the diagnosis and management of glaucoma patients.

Reference

Correlation of macular thickness with visual fields in glaucoma patients and suspects.
Mathers K, Rosdahl J, Asrani S.
JOURNAL OF GLAUCOMA
2014;23(2):98-104.

Journal of Pediatric Ophthalmology and Strabismus

Amblyopia OCT results
Reviewed by: Fiona Rowe
Vol 20 No 6
 

The authors compared the macular and peripapillary retinal nerve fibre layer (RNFL) thicknesses of amblyopic and fellow eyes using Stratus optical coherence tomography (OCT) to reveal any differences. They sought to determine the anatomical differences between these subtypes of strabismic and anisometropic amblyopia. They recruited 25 strabismic (22 esotropia and three exotropia) and 25 anisometropic (21 anisohyperopic and four anisomyopic) subjects. In the anisometropic group macular thickness of amblyopic eyes was significantly greater than the fellow eye. No significant difference in RNFL thickness was found for this group. In the strabismic group, no significant difference between eyes was found either for macular or RNFL thickness.

Reference

Macular and retinal nerve fibre layer thickness in unilateral anisometropic or strabismic amblyopia.
Andalib D, Javadzadeh A, Nabai R, Amizadeh Y.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:218-21.

Journal of Pediatric Ophthalmology and Strabismus

Intermittent exotropia
Reviewed by: Fiona Rowe
Vol 20 No 6
 

Four cases of intermittent exotropia are discussed. Case 1 was a nine-month-old with cycloplegic refraction of +1.0DS and a 30PD intermittent exotropia at near and distance. Discussions considered observation, part-time occlusion, refractive correction and later possibility of surgery. Case 2 was a three-year-old with intermittent exotropia of 20PD at near but constant at distance and with +1.25 retinoscopy. Discussions considered duration of exotropia, possible surgery, quick follow-up, observation and checks for presence of photophobia. The third case was a five-year-old with 20PD exotropia at near and distance. One eye closed at distance with a retinoscopy of +4.50DS. Discussions considered providing full or partial hyperopic glasses for better visual acuity which may improve control, possible surgery and risk of consecutive esotropia. The final case was a four-year-old with 20PD exotropia at near and 25PD at distance with -1.50DS refraction. Discussions considered giving full minus glasses and observation.

Reference

Eye to Eye: Evaluation and treatment of intermittent exotropia.
Panelists: Alley C, Deutsch JA, Gunton KB.
Moderator: Nelson LB.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:198-201.

Journal of Pediatric Ophthalmology and Strabismus

Risk factors for amblyopia
Reviewed by: Fiona Rowe
Vol 20 No 6
 

The author presents a meta-analysis of published data to estimate American Association for Pediatric Ophthalmology and Strabismus (AAPOS) prevalence data for amblyopia risk factors. He extracted data from major paediatric comprehensive eye examination studies for children aged two to five years. Prevalence at AAPOS consensus thresholds for risk factors were: anisometropia (1.2%±2%), hyperopia (6%±1%), astigmatism with the rule and 15 degree against the rule (9%±1%), oblique astigmatism (6%±1%), myopia (0.5%±0.1%) and refraction total (23%±2%). Strabismus prevalence was 2%±0.3%. Prevalence of acuity failure of 20/40 or two inter eye line difference was 6%±1%. Total AAPOS risk factors were 31%±2%. Taking interactive risk factors into account reduces refractive and strabismic components to 16%±2%. Assuming 50% interaction with visual acuity and other combined risk factors yields a prevalence of 21%±2%.

Reference

Amblyopia risk factor prevalence.
Arnold RW.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:213-7.

Journal of Pediatric Ophthalmology and Strabismus

Surgical prediction in infantile ET
Reviewed by: Fiona Rowe
Vol 20 No 6
 

The purpose was to evaluate the preoperative factors influencing the efficacy of the surgical procedure of bilateral lateral rectus recessions. Fifty cases with at least one year follow-up were included for retrospective analysis. Mean response to surgery was 2.17±0.80 PD/mm recession at one week postoperative, 1.79±0.63 at six weeks postoperative and 1.58±0.75 at one year postoperative. Exo drift was 5.12±7.27PD at six weeks postoperative and 8.02±6.81 at one year. A larger preoperative distance deviation was associated with larger surgical response at six weeks postoperative. Younger age at surgery, shorter interval between onset and surgery and larger preoperative distance deviation were associated with larger surgical response at one year. Exo drift and extent of preoperative distance angle should
be considered when determining surgical dose for infantile exotropia.

Reference

Preoperative factors predict the surgical response of bilateral lateral rectus recession surgery in patients with infantile exotropia.
Yam JCS, Chong GSL, Wu PKW, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:245-50.

Journal of Refractive Surgery

High-fluence collagen cross-linking
Reviewed by: Amit Patel
Vol 20 No 6
 

The authors treat seven eyes with progressive keratoconus with a high energy (18mW) for five minutes delivering a total energy similar to that suggested by the original Dresden protocol (3mW for 30mins). All eyes had a thickness >400µm following epithelial removal and were treated with iso-osmotic riboflavin. Corrected distance visual acuity (CDVA), keratometry (Kmax and K mean) and endothelial cell density (ECD) were measured at each follow-up. No intra or postoperative complications were noted. At one and six months postoperatively, there was no significant change in Kmax, Kmean or ECD. The authors claim that the Bunson-Roscoe law of reciprocity can be applied effectively by increasing the power and shortening the duration of treatment, but acknowledge the small numbers and short duration of study.

Reference

Impact of fluorescein on the antimicrobial efficacy of photoactivated riboflavin in corneal collagen cross-linking.
Richoz O, Gatzioufas Z, Francois P, et al.
JOURNAL OF REFRACTIVE SURGERY
2013;29(12):842-5.

Journal of Refractive Surgery

Prostaglandin levels in femto cataract surgery
Reviewed by: Amit Patel
Vol 20 No 6
 

Following previous reports of pupil size decrease after femtosecond treatment, the authors compare levels of prostaglandins in patients undergoing femtosecond assisted cataract surgery with those having routine cataract surgery. Patients with inflammatory eye disease, previous trauma surgery, age-related macular degeneration (AMD), retinopathy, glaucoma, non-steroidal anti-inflammatory (NSAID) use and small pupils were excluded. Aqueous humour was collected from patients after femtosecond laser pretreatment (n=113) and at the beginning of routine cataract surgery (n=107). In all femtosecond assisted cases, a set capsulotomy size was used and the programmed pulse energy, incision depth and grid spacing were standardised. The total prostaglandin (PG) and the prostaglandin E2 (PGE2) concentrations were measured in two independent studies each using an enzyme-linked immunoassay. In both sets of studies, there was a significantly higher concentration of PG (p=0.0001, p=0.00004) and PGE2 (p=0.0002, p=0.004) in the femtosecond group compared to routine cataract surgery group. No correlation of PG/PGE2 levels with age, cataract density, corneal incision type, suction time or laser time was noted. The authors therefore postulate that the possible trigger for prostaglandin release is from the microplasma of gas and water that results from the laser application. They suggest that patients undergoing femtosecond assisted cataract surgery should be pretreated with topical NSAIDs to avoid intraoperative mioses and postoperative inflammation.

Reference

Changes in prostaglandin levels in patients undergoing femtosecond laser-assisted cataract surgery.
Schultz T, Joachim SC, Kuehn M, et al.
JOURNAL OF REFRACTIVE SURGERY
2013;29(11):742-7.

Journal of Refractive Surgery

Two bifocals and a trifocal
Reviewed by: Amit Patel
Vol 20 No 6
 

The authors compare the optical outcomes of two bifocal intraocular lenses (AcrySof ReSTOR +2.50 Diopter [D] add +3.0D add) with a trifocal lens (AT LISA tri 839MP). The optical qualities of the lenses were quantified by measuring the modulation transfer function (MTF) at five different focal points (0D, -1.5D, -2.0D, -2.5D and -3.0D) and four apertures (2.0mm, 3.0mm, 3.75mm and 4.5mm). At far distance (0D), the bifocal +2.0D lens performed best, at -2.5D and -3.0D, the bifocal +3.0D add lens performed best and the trifocal provided best MTF values at -1.5D. All three lenses had a similar performance at -2.0D. As expected the trifocal lens showed less aperture (pupil) dependence than the bifocal lenses. As an experimental study, the authors acknowledge that the results are obtained for an ideal lens centration and in vivo outcomes may differ due to tilt and decentration.

Reference

Optical quality differences between three multifocal intraocular lenses: bifocal low add, bifocal moderate add, and trifocal.
Madrid-Costa D, Ruiz-Alcocer J, Ferrer-Blasco T, et al.
JOURNAL OF REFRACTIVE SURGERY
2013;29(11):749-54.

Neuro-Ophthalmology

A case report of cavernous sinus syndrome following dental procedure
Reviewed by: Claire Howard
Vol 20 No 6
 

This case report describes a patient presenting with painful diplopia as a consequence of root canal dental treatment. Following root canal treatment a non-resolving tooth pain led to a decision to extract the tooth, leading to onset of severe periorbital pain, diplopia, headache, nausea and vomiting the next day. Magnetic resonance imaging demonstrated a mass lesion in the cavernous sinus. Corticosteroid therapy was started and marked pain relief occurred within 72 hours. Following five months of treatment there was complete resolution of diplopia and a normal appearance of the affected cavernous sinus. Cavernous sinus thrombosis is usually caused by infection but this was not the case here, as the problematic tooth was not infected. The authors question that the cause of ophthalmoplegia could be the intraorbital local anaesthetic injection used. Neuroimaging is suggested in cases of non-resolving cavernous sinus syndromes.

Reference

Painful ophthalmoplegia following dental procedure.
Bahceci Simsek I, Yabas Kiziloglu O, Ziylan S.
NEURO-OPHTHALMOLOGY
2013;37(4):165-8.

Neuro-Ophthalmology

An interesting presentation of ruptured anterior communicating artery aneurysm with acute monocular vision loss
Reviewed by: Claire Howard
Vol 20 No 6
 

The authors report an interesting case of a 60-year-old man presenting with acute monocular vision loss accompanied by periorbital pain as an unusual presentation of subarachnoid haemorrhage (SAH) from ruptured anterior communicating artery aneurysm. The patient did not present with any neurological deficit, which is generally the presenting feature for this condition. In addition, changes in mental status are known to occur which, again, was not found for this reported case. A relative afferent pupillary defect was present in the affected eye. As the anterior communicating artery is located close to the optic nerve, aneurysm should be considered when there is presentation of unilateral decrease in visual acuity with periorbital pain, even in the absence of other neurological signs. Other symptoms to look for include transient headache and / or bitemporal or homonymous hemianopia (due to compression of the optic chiasm or tract). In this case, direct optic nerve compression from perineural haematoma was suggested as a cause for retrobulbar optic neuropathy.

Reference

Acute retrobulbar optic neuropathy as the sole manifestation of subarachnoid haemorrhage from a ruptured anterior communicating artery aneurysm.
Lee K, Young Shin S, Hae Park S.
NEURO-OPHTHALMOLOGY
2013;37(4):172-4.

Neuro-Ophthalmology

Case reports of neuro-ophthalmological complications of CIPD
Reviewed by: Claire Howard
Vol 20 No 6
 

The authors present three cases of neuro-ophthalmological complications of chronic inflammatory demyelinating polyradiculoneuropathy (CIPD). CIPD can lead to prominent nerve hypertrophy which can mimic other forms of neuropathy radiologically. In addition, complications can occur which can cause diagnostic difficulties. All three cases reported have the presence of hypertrophic nerve enlargement. A review of literature for large case series and single case reports shows a small percentage of patients with the disease to have neuro-ophthalmological complications. The neuro-ophthalmological presentation usually occurs following a long history of CIPD. The authors discuss the implication of clinicians being aware of the possibility of CIPD in neuro-ophthalmological presentations, especially if neuro imaging reveals cranial / spinal nerve root hypertrophy or if raised cerebrospinal fluid (CSF) protein is detected. Best treatment for the complications is to treat the underlying condition with appropriate immunosuppression. Other treatment options for refractory papilloedema include acetazolamide, optic nerve sheath fenestration and CSF diversion surgery.

Reference

Neuro-ophthalmological complications of chronic inflammatory demyelinating polyradiculoneuropathy.
Hickman SJ, Allen JA, Baisre A, et al.
NEURO-OPHTHALMOLOGY
2013;37(4):146-56.

Ocular Immunology and Inflammation

Inflammatory macular holes
Reviewed by: Saruban Pasu
Vol 20 No 6
 

The authors present a case of closure of a full thickness macular hole in a patient with Behçet’s disease, without surgery. The 23-year-old male they describe presented with a history of recurrent oral aphthous ulcers and a genital ulcer. Ocular examination revealed inflammation of the anterior chamber and vitreous of the right eye, and periphlebitis and cystoid macular oedema in the left eye. He was prescribed hourly topical corticosteroids, cycloplegics and oral azathioprine. Follow-up examinations revealed the development of a retinal infiltrate in the right eye which promoted the addition of oral cyclosporine A and oral corticosteroids. Three months after initial presentation he developed an attack of panuveitis in the left eye, which was adequately controlled by increasing the dose of oral corticosteroids. Subsequent follow-up revealed a full thickness macular hole in the left eye. The patient was put on the waiting list for surgical closure of the macular hole. In the meantime he developed another attack of panuveitis in his left eye. Subcutaneous interferon alpha-2b treatment was started and tapered accordingly. Two months after treatment the macular hole had fully closed with an increase in the patient’s visual acuity. The authors highlight the role of cystoid macular oedema and abnormal vitreoretinal tractions secondary to inflammation in contributing to macular hole formation. In this particular case the authors suggest that the second attack of inflammation may have caused glial or retinal pigment epithelium (RPE) cell proliferation to bring the hole edges closer together. Subsequent control of the inflammation caused resolution of the cystoid macular oedema and release of vitreous traction. They conclude by saying surgery may be avoided by strict control of inflammation in Behçet’s disease macular holes.

Reference

An exceptional case of full-thickness macular hole closure in a patient with Behçet disease.
Uçar D, Atalay E, Ozyazgan Y, et al.
OCULAR IMMUNOLOGY AND INFLAMMATION
2014;22(1):79-81.

Ocular Immunology and Inflammation

IVTA use in Behçet’s disease
Reviewed by: Saruban Pasu
 

This study aimed to evaluate the efficacy and safety of intravitreal triamcinolone acetonide (IVTA) injection (4mg/0.1ml) in controlling posterior segment inflammation in patients with Behçet’s disease. Medical records of consecutive patients diagnosed with Behçet’s who underwent IVTA between July 2005 and February 2001 were reviewed. Forty-nine eyes of 49 patients were included in the study. A total of 67.3% were on oral prednisolone of more than 10mg/day and 79.6% were on immunosuppressants. At 24 months after injection 49.0% were on a reduced dose or had stopped oral prednisolone and / or second line immunosuppressants. Mean number of acute attacks during one year before injection was 1.93+/-0.85, which reduced to 0.88+/-0.89 during one year after injection (p<0.001). Mean follow-up period after injection was 54.9+/-17.5 months. Mean best corrected visual acuity (BCVA) improved at 1, 3, 6, 12, 18, 24 and final visit (p<0.001). The cumulative survival of inflammation control without relapse was 40.0% at 12 months, 22.5% at 24 months, and 16.4% at 36 months after IVTA injection. During the 24 months after injection, 30.6% needed further injections at a median period of 10 months after the first. After injecting, 25% showed complete resolution of vascular and disc leakage on fundus flourescein angiography (FFA); 68.8% showed incomplete resolution. The cumulative probabilities of cataract surgery for phakic eyes were 13.8% at 12 months, 48.9% at 24 months and 60.2% at 36 months after IVTA injection. Twenty (40.8%) eyes had an elevated intraocular pressure (IOP) post injection. The rate of IOP elevation did not differ according to the history of glaucoma or IOP elevation history (p=0.740). Of these 20, 15 had no previous elevated IOP history and only one went on to have a trabeculectomy. Five patients with a post injection raised IOP had a previous history of elevated IOP and two of these underwent trabeculectomy. The authors conclude that although its anti-inflammatory effect is temporary and repeated injections are often necessary, IVTA injection is an effective therapeutic option for rapid vision restoration, inflammation control, and prevention of recurrence. Long-term follow-up revealed that ocular complications such as cataract progression and IOP elevation could decrease its efficacy and repeatability.

Reference

Long-term outcome of intravitreal triamcinolone acetonide injection for the treatment of uveitis attacks in Behçet disease.
Park UC, Park JH, Yu HG.
OCULAR IMMUNOLOGY AND INFLAMMATION
2014;22(1):27-33.

Ophthalmology

Complement Factor H and Factor H-Like protein are expressed in human RPE cells
Reviewed by: Brian Ang
Vol 20 No 6
 

The role of inflammation in age-related macular degeneration (AMD) is well documented and the association of AMD with the inflammatory marker C-reactive protein (CRP) and members of the complement system underline the role of complements in AMD. Human complement factor H controls spontaneous activation of the complement cascade, protects from oxidative stress and plays a major role in regulation of the alternative pathway of complement. In this study, retinal epithelial cells (RPE), i.e. immortalised ARPE-19 as well as primary human RPE cells, were investigated for expression of factor H and FHL-1 by immunohistochemistry and in situ hybridisation analysis. Factor H and FHL-1 are expressed in RPE cells and their expression was induced in a dose-dependent manner in ARPE-19 cells upon treatment with the inflammatory marker interleukin-6 (IL-6). Local synthesis of complement regulators affects the protection of retinal cells and may be involved in the pathogenesis at the RPE-choroid interface in AMD.

Reference

Human Complement factor H and Factor H-like protein 1 are expressed in human retinal pigment epithelial cells.
Weinberger AWA, Eddahabi C, Carstesen D, et al.
OPHTHALMIC RESEARCH
2014;51(2):59-66.

Ophthalmology

Randomised trial of multifocal intraocular lens versus monovision
Reviewed by: Brian Ang
Vol 20 No 6
 

The authors report on a randomised, multicentre clinical trial comparing the outcomes of Tecnis ZM900 diffractive multifocal intraocular lenses (IOL) versus monovision with Akreos AO monofocal IOL (dominant eye targeted for emmetropia and non-dominant eye targeted for -1 to -1.50 dioptre myopia). A total of 212 patients with bilateral cataract and no other ocular pathology were randomised to either multifocal IOL or monovision. One hundred and eighty-seven patients (88%) returned for assessment four months after surgery. There was no significant difference between the two groups in terms of binocular distance visual acuity. However, the multifocal IOL group performed worse for intermediate distance vision, and the monovision group performed worse for near vision. More patients in the multifocal IOL group achieved spectacle independence (71.3%) compared to the monovision group (25.8%). Patients in both groups were highly satisfied with their visual outcomes, but the multifocal IOL group had higher levels of symptomatic dysphotopsia symptoms. In the first postoperative year, six patients (5.7%) in the multifocal IOL group underwent IOL exchange (four bilateral; two unilateral) mainly due to dissatisfaction with image quality. No patient in the monovision group underwent IOL exchange. This is a well-conducted randomised clinical trial, which confirms both the benefits and disadvantages of multifocal IOLs compared to monovision.

Reference

Randomized trial of multifocal intraocular lenses versus monovision after bilateral cataract surgery.
Wilkins MR, Allan BD, Rubin GS, et al.
OPHTHALMOLOGY
2013;120:2449-55.

Ophthalmology

Therapeutic ocular surface medium for persistent corneal epithelial defect
Reviewed by: Brian Ang
Vol 20 No 6
 

Corneal ulcers and persistent epithelial defects (PEDs) are caused by a variety of different insults to the cornea, which includes limbal epithelial stem cell failure. PED may be resistant to healing with standard therapy such as frequent ointments and / or lubricants, particularly if there is coexistent ocular pathology. This study investigates the efficacy of therapeutic ocular surface medium (TOSM), a potential physiological tear replacement therapy, for persistent epithelial defects. TOSM is a manufactured serum substitute designed specifically to culture epithelial cells in the laboratory. It contains many essential tear components, such as growth factors. Eleven eyes of 10 patients with persistent epithelial defects (two weeks plus) without improvement with conventional therapy were enrolled in this prospective study of TOSM over one month. Healing of the PED occurred in three out of 11 eyes at one, two and four weeks respectively. At week four, two eyes were almost healed. In four of the remaining eyes, the PED area was reduced. One patient with end-stage ocular cicatricial pemphigoid with severe dry eye failed and one withdrew from the study due to mild allergic reaction.

Reference

Clinical study of therapeutic ocular surface medium for persistent epithelial defect.
Watson SL, Geerling G, Dart JKG.
OPHTHALMIC RESEARCH
2014;51(2):82-6.

Orbit

A retrospective study of the use of Dermis Fat Grafts for orbital volume augmentation
Reviewed by: Konal Saha
Vol 20 No 6
 

The authors describe the outcomes of 173 primary Dermis Fat Grafts (DFGs) and 66 secondary DFGs. Median follow-up for the primary group was 21.5 months and 14 months for the secondary group. Outcome measures included: prosthesis motility, prosthesis fit, patient / parent satisfaction and complications. After primary DFG motility was deemed excellent in 76%, patient satisfaction was excellent in 83% and prosthetic fitting excellent in 81%. After secondary DFG these results fell to: 34%, 57% and 49% respectively. The most common major complication following primary or secondary DFG was graft atrophy (3.5% after primary and 6.1% after secondary). The authors conclude that DFG is a useful option for augmenting orbital volume. The technique may have significant benefit in areas where allograft implants are not available or where implant infection may be a significant risk.

Reference

Dermis fat grafts as primary and secondary orbital implants.
Nentwich MM, Schebitz-Walter K, Hirneiss C, Hintschich C.
ORBIT
2014:33(1);33-8.

Orbit

Prognosticating ocular adnexal lymphoma
Reviewed by: Konal Saha
Vol 20 No 6
 

The authors retrospectively analyse 160 patients with primary ocular adnexal lymphoma to determine the accuracy of prognosis based on the Ann Arbor classification and how this compares to the accuracy of prognosis based on retrospectively applying the newer Tumor, Node, Metastasis (TNM) based classification system. The authors conclude that the TNM-based classification is more accurate in predicting prognosis, with bilaterality of disease, positive lymph nodes and / or metastases being important predictors of a poorer prognosis. These factors are recorded in the TNM classification but not the Ann Arbor classification. There is a significant potential confounder, with the treatment for the different stages of ocular adnexal lymphoma, based on the Ann Arbor classification influencing their prognosis, hence, invalidating the retrospective application of the TNM classification. The authors suggest a simplified version of the TNM classification. If patients are split into three groups: 1. unilateral disease, 2. bilateral or positive lymph node or metastasis, 3. bilateral with positive lymph node or metastasis; the following prognosis can be estimated (10 year progression free survival): group 1 – 75%, group 2 – 50%, group 3 – 0%.

Reference

Comparison of American joint committee on cancer TNM-based staging system (7th edition) and Ann Arbor classification for predicting outcome in ocular adnexal lymphoma.
Rath S, Connors JM, Dolman PJ, et al.
ORBIT
2014;33(1):23-8.

Retina

Clinical course of vitreomacular adhesion managed by initial observation
Reviewed by: Nikolaos Georgakarkos
Vol 20 No 6
 

The purpose of this study was to investigate the clinical course of patients with idiopathic vitreomacular adhesion (VMA) with a noncomparative case series of patients who had clinical symptoms and spectral-domain optical coherence tomography findings consistent with VMA. The VMA was graded based on the optical coherence tomography findings at initial and follow-up examinations. Grade 1 was incomplete cortical vitreous separation with attachment at the fovea, Grade 2 was the Grade 1 findings and any intraretinal cysts or clefts, and Grade 3 was the Grade 2 findings and the presence of subretinal fluid. Results: 106 eyes of 81 patients were identified as having VMA by spectral-domain optical coherence tomography with mean age at 73 years and the mean time of follow-up was 23 months. Forty-three eyes (41%) had Grade 1 VMA, 56 eyes (52%) had Grade 2 VMA, and seven eyes (7%) had Grade 3 VMA. By the last follow-up, spontaneous release of VMA occurred in 34 eyes (32%), and pars plana vitrectomy was performed in five eyes (4.7%). Mean best corrected visual acuity was 0.269 logarithm of the minimum angle of resolution or 20/37 at baseline (range, 20/20–20/200) and logarithm of the minimum angle of resolution 0.251 or 20/35 at the last examination (range, 20/20–20/400). The study concluded that in this selected patient cohort with mild symptoms, the clinical course of patients with VMA managed by initial observation was generally favourable.

Reference

Clinical course of vitreomacular adhesion managed by initial observation.
Vishak J, Flynn H, Smidy W, et al.
RETINA
2014;34:442-6.

Strabismus

Autistic responses to plusoptix photoscreening
Reviewed by: Fiona Rowe
Vol 20 No 6
 

The authors sought to determine if the plusoptix would provide an accurate estimation of whether an autistic child had amblyopic risk factors. This retrospective study identified 48 children with autism. Undilated plusoptix was undertaken in 25 children aged less than one year up to 15 years (average six). Amblyopic risk factors were found in 17 children (68%): nine with refractive amblyopia, four with accommodative esotropia, two with exotropia, one with Duane’s retraction syndrome and one with partially accommodative esotropia. Plustopix had sensitivity of 88%, specificity of 87%, false positive of 18%, false negative of 12%, positive predictive value of 94% and negative predictive value of 78%. Plusoptix
was found to be useful for screening children with autism.

Reference

Evaluation of plusoptix photoscreening during examinations of children with autism.
Singman E, Matta N, Fairward A, Silbert D.
STRABISMUS
2013;21:103-5.

Strabismus

BV after long-standing exotropia
Reviewed by: Fiona Rowe
Vol 20 No 6
 

Pre and postoperative binocular vision (BV) was compared in long-standing large angle exo deviations. The purpose was to determine the BV potential in these cases and particularly for those at risk of postoperative paradoxical diplopia. In this retrospective study patients were grouped according to preoperative BV status. Group A had evidence of BV preoperatively with normal retinal correspondence. Group B had suppression on all tests. Group C had abnormal retinal correspondence. Twenty patients were identified with eleven in group A, five in group B and four in group C. Fusion and / or stereopsis was present in 17 cases postoperatively. The results demonstrate that constant large angle long-standing childhood onset strabismus does not preclude obtaining binocular potential postoperatively.

Reference

Binocular vision outcomes following surgery for long-standing large angle exodeviations.
Gill LK, Arnoldi K.
STRABISMUS
2013;21:123-6.

Strabismus

TAC testing in dementia
Reviewed by: Fiona Rowe
Vol 20 No 6
 

The aim was to assess the visual acuity measurements performed by the preferential looking method using Teller acuity cards (TAC) in elderly subjects with dementia due to probable Alzheimer’s disease. The mean age was 78.2±9.11 years for patients and 77.2±6.19 years for controls. Controls consisted of older volunteers with no cognitive decline and all aged over 65 years. Patients had a mean MMSE score of 12.15±7.29 versus 27.3±3.07 for controls which was significantly different. Visual acuity was tested with recognition Lea symbols and with TAC. Visual acuities with both measures were well correlated. The authors propose the use of TAC as a viable alternative method for assessment of acuity in dementia patients who may not be able to perform traditional recognition acuity tests.

Reference

Assessment of visual acuity in patients with dementia using Teller acuity cards.
Froiman PC, Dantas PEC.
STRABISMUS
2013;21:93-7.

Acta Ophthalmologica

Ocular characteristics in Marfan syndrome
Reviewed by: Nana Theodorou
Feb/Mar 2014 (Vol 20 No 5)
 

Marfan syndrome (MFS) is a genetic disorder with clinical manifestations associated with cardiovascular, ocular and skeletal organ systems. Typical signs are descending aortic root aneurysms, ectopia lentis, tall stature and scoliosis. This observational study looked at the ocular characteristics, visual acuity and biometric values of 102 eyes in 51 patients with MFS. The mean patient age was 39 years (range, 12.7–71.6). Seventy-seven eyes were phakic, five aphakic and 20 pseudophakic. Thirty-one eyes had ectopia lentis, 12 cataract, nine strabismus, five glaucoma and four had undergone surgery for retinal detachment. Ninety-two per cent eyes had a best spectacle-corrected vision of 0.3 logMAR or better. In the 77 phakic eyes, myopia exceeding −3 D was seen in 39% eyes with ectopia lentis, and in 26% eyes without ectopia lentis. The mean axial length (AL) was 24.73mm and abnormally increased AL (≥24.5mm) in 51% eyes. No significant difference was found in refraction, axial length or corneal curvature between eyes with and without ectopia lentis. The authors conclude that in addition to ectopia lentis, increased axial length and a flattened cornea are typical characteristics in MFS. High myopia was not as common in MFS as expected because of a flat cornea

Reference

A descriptive study of ocular characteristics in Marfan syndrome.
Konradsen TR, Zetterström C.
ACTA OPHTHALMOLOGICA
2013;91:751-5.

Acta Ophthalmologica

Visual impairment in patients with glaucoma
Reviewed by: Nana Theodorou
Feb/Mar 2014 (Vol 20 No 5)
 

This retrospective observational study assessed the prevalence of end-of-life visual impairment in patients with glaucoma. A total of 122 deceased patients followed for glaucoma were included and data was collected from patient notes. Sixty-one patients had open-angle glaucoma and 61 patients were suspect for glaucoma or had ocular hypertension. The mean age at death was 82 years with a mean previous follow-up of nine years. Seventy-three per cent of all patients had their last visit in the year preceding death. Visual impairment was defined as a mean deviation value <−15 dB or a Snellen visual acuity <0.3 (20/60) of the better eye. For patients with open-angle glaucoma, 26% had an end-of-life visual impairment and in 15% this was caused by glaucomatous disease due to loss of visual acuity in 16%. This was mainly explained by ocular comorbidity, and there was an equal contribution of comorbidity and glaucoma in one case. Eight per cent of the glaucoma suspects or patients with ocular hypertension were visually impaired at death and these were all caused by ocular comorbidity. The authors conclude substantial visual loss at baseline is an important contributing factor.

Reference

Prevalence of end-of-life visual impairment in patients followed for glaucoma.
Ernest PJG, Busch MJWM, Webers CAB, et al.
ACTA OPHTHALMOLOGICA
2013;91:738-43.

British Journal of Ophthalmology

Mid-term evaluation of the new Glaukos iStent
Reviewed by: Jonathan Chan
Feb/Mar 2014 (Vol 20 No 5)
 

This is a prospective non-randomised interventional study to assess the efficacy and safety of the Glaukos GTS-400 iStent combined with cataract surgery. The patients enrolled in the study had cataract and primary open angle glaucoma, pseudoexfoliation glaucoma or ocular hypertension. A total of twenty patients were enrolled in the study, with an average age of 75.1±8.6 years. After the phacoemulsification and intraocular lens (IOL) placement, two GTS-400 iStents were implanted through the clear corneal incision (~2.85mm) placed for phacoemulsification. A Swan-Jacob gonioscope was used for the insertion at the nasal part of the trabecular meshwork. Post-operative visits were scheduled for one day, one week, three months, six months and one year. Three patients received one iStent for logistic reasons. The mean IOP with medication was 19.95±3.71mmHg and after washout of anti-glaucoma drops was 26±3.11mmHg. At the end of follow-up the mean IOP was 16.75±2.24mmHg, determining a final IOP reduction of 35.68% (p<0.001). At baseline, the mean number of glaucoma medications was 1.3, with a range of zero to two medications. At the final visit, the mean number of medications use had fallen to 0.3 (p<0.001). Fifteen subjects (75%) required no ocular hypertensive medication. One year after surgery, complete success was achieved in 10 of the patients (50%), while relative success was recorded in 19 of 20 patients (85%). Complete success was defined as IOP reduction to <18mmHg without medication; relative success was defined as IOP reduction to <18mmHg with medication or to <21mmHg without medication. Transient IOP elevation to above 30mmHg was observed in three eyes one day post-operatively, probably due to the persistence of viscoelastic. By the one week visit this transient IOP elevation had resolved in all three eyes. The authors concluded that combined cataract surgery with GTS-400 iStent implantation seems to be an effective and safe procedure.

Reference

Mid-term evaluation of the new Glaukos iStent with phacoemulsification in coexistent open-angle glaucoma or ocular hypertension and cataract.
Arriola-Villalobos P, Martínez-de-la-Casa JM, Díaz-Valle D, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:1250-5.

British Journal of Ophthamology

Morning glory syndrome associated with PHPV
Reviewed by: Jonathan Chan
Feb/Mar 2014 (Vol 20 No 5)
 

This is a retrospective review of the medical records of 85 eyes / 74 patients diagnosed as morning glory syndrome (MGS) in the clinic between November 2009 and November 2012. Twenty two eyes of 19 patients diagnosed as having MGS associated with persistent hyperplastic primary vitreous (PHPV) were included in this study (25.88% of all the MGS eyes). Microphthalmia was diagnosed if the axial length of the eye was less than at least two standard deviations (SDs) below the mean for the age of the patient. All patients were recommended to have cranial magnetic resonance imaging (MRI) and MR angiography (MRA) or computerised tomography (CT) scan. Only eight patients underwent examinations due to financial constraints. Nineteen of 22 eyes (86.36%) had associated findings including cataracts (10 eyes), secondary glaucoma (eight eyes), corneal leucoma or oedema (eight eyes), retinal detachment (eight eyes), strabismus (three eyes) and nystagmus (two eyes). Lensectomy and / or vitrectomy were performed in patients with complications of glaucoma, cataract and retinal detachment by the same retinal surgeon. Of eight patients who had cranial MRI/MRA or CT examination, three patients showed abnormalities; one patient was found to have widening of the cerebral fissures of the bilateral temporal lobes, one patient showed an abnormal dilated branch of the middle cerebral artery in the left hemisphere and the other patient showed an abnormal signal in the grey matter of the frontal and occipital lobes. The authors postulated that there might be the coexistence of a genetic link between the PHPV and MGS.

Reference

Clinical characteristics and treatment of 22 eyes of morning glory syndrome associated with persistent hyperplastic primary vitreous.
Fei P, Zhang Q, Li J, Zhao P.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:1262-7.

British Journal of Ophthamology

Clinical evaluation of a multifocal aspheric diffractive intraocular lens
Reviewed by: Jonathan Chan
Feb/Mar 2014 (Vol 20 No 5)
 

This is a multi-centre prospective study involving five different centres in Europe including 52 patients with cataract. The average age was 68.5±10.5 years, 35 females were bilateral implanted with aspheric diffractive multifocal lens implantation of the Tecnis 1-Piece multifocal intraocular lens (IOL), model ZMB00. This is a one piece acrylic foldable posterior chamber lens with and near add of +4D with a ‘C’ loop haptic, designed to be implanted in the capsular bag following phacoemulsification cataract extraction. The lens is made of ultraviolet absorbing hydrophobic acrylic material and has a 6.0mm optic and overall length of 13.0mm. All patients were assessed with a questionnaire regarding the visual symptoms and the satisfactions and corrections of the visual requirement. This was carried out approximately four to six months after the completion of the surgery, including the uncorrected, best corrected distance and near visual acuity, under photopic and mesopic lighting, reading ability, defocus curve testing and ocular examination for complications. All patients underwent cataract surgery under topical anaesthetic, using extended suture microincision phacoemulsification technique. The intraocular lens was implanted into the capsular bag with an injection system. Postoperatively, topical therapy included a combination of antibiotics and steroidal agents were used. The second eye was performed within six weeks of the initial operation. The residual refractive error was 0.01±0.47 D with 56% of the eyes within ±0.25D and 97% within ±1D. The uncorrected visual acuity was 0.02±0.1 logMAR at distance and 0.15±0.3 logMAR at near. It only reduced to 0.7±0.1 logMAR at distance and 0.21±0.25 logMAR at near in mesopic conditions. The defocus curve showed a near addition between 2.5 and 3.0 D, allowing a reading acuity of 0.08±0.13 logMAR with a range of clear vision of less than 0.3 logMAR of approximately 4.0D. The average reading speed was 121.4±30.8 words per minute. Spectacle independence was 100% for distance and 88% for near, with high levels of satisfaction reported. The overall rating for vision without glasses could be explained by preoperative best-corrected distance acuity, postoperative reading acuity and postoperative uncorrected distance acuity in photopic conditions (p<0.001). Four patients (8%) reported glare at night and two different patients (4%) noted glare symptoms during the day. One patient had cystoid macular oedema in one eye which resolved with steroid treatment within three months and one patient had conjunctival hyperaemia and photophobia caused by dry eyes which resolved with anti-inflammatory drugs. The authors conclude that the ZMB00 1-piece Tecnis multifocal IOL provides a good visual outcome at near and distance with minimal adverse effects.

Reference

Clinical evaluation of a multifocal aspheric diffractive intraocular lens.
Schmickler S, Bautista CP, Goes F, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:1560-4.

British Journal of Ophthamology

Secondary intraocular lens implantation in children
Reviewed by: Jonathan Chan
Feb/Mar 2014 (Vol 20 No 5)
 

This is a retrospective study of the medical records of children under the age of 16 who underwent secondary lens implantation for aphakic corrections after previous congenital cataract surgery over a period between January 2000 and December 2010. The study analysed the outcome of refraction, prediction error (PE) and factors affecting PE in children with aphakia were evaluated in this study. In total 174 eyes of 104 children between the age of 6.08±3.75 years were analysed. The mean value of PE was 1.6 dioptres (range -3.25 to 7.5D) and mean absolute PE was 2.15 (range 0-7.5D) at three months. The younger and uncooperative children had the keratometer readings measured under anaesthetic intraoperatively using a Nidek KM 500 handheld keratometer and the axial length was measured with a contact A-scan with OcuScanRxP. All intraocular lens power calculations were performed using a Sanders-Retzlaff-Kraff (SRK) II formula. It was found that the absolute PE was statistically significant between eyes with the intraocular lens (IOL) implantations calculated with the IOL master (1.8±1.40D) versus IOL calculation under anaesthesia with contact method (2.43±1.83D), p=0.01. Multiple regression analysis showed there is an inverse relationship between a secondary intraocular lens implantation and mean absolute PE (p=0.01). The surgical technique was standardised to a superior scleral tunnel technique and a polymethylmethacrylate (PMMA) IOL was used or alternatively clear corneal incisions for acrylic foldable (three piece) IOLs were inserted. A paracentesis site was situated at 10 and 2 o’clock positions for the removal of the re-proliferative lens material. The authors concluded that SRK II formula intraocular power calculations with sulcus placement gives more favourable refractive outcomes for the placement of intraocular lens implants. Although the age base refraction was targeted, a significant PE may be expected from the calculation.

Reference

Refractive outcome and prediction error following secondary intraocular lens implantation in children: a decade-long analysis.
Shenoy BH, Mittal V, Gupta A, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013:97:1516-9.

Clinical and Experimental Ophthalmology

Mitomycin C versus 5-FU as an adjunctive treatment for trabeculectomy
Reviewed by: Anjali Gupta
Feb/Mar 2014 (Vol 20 No 5)
 

Antifibrotic agents are used during trabeculectomy (TRAB) to improve long-term surgical success by reducing fibrosis of subconjunctival and episcleral tissue. The purpose of this meta-analysis was to directly compare the efficacy and safety of the two most frequently used antifibrotic agents, Mitomycin C (MMC) vs. 5-FU, when used as adjunctive therapy for TRAB. A systematic review was performed in April 2011. All randomised controlled trials (RCTs) comparing 5-FU directly with MMC were eligible for inclusion. Other inclusion criteria included age ≥18 years, glaucomatous optic disc features and intraocular pressure (IOP) ≥21. Five RCTs met the inclusion criteria, totalling 416 participants. MMC was associated with a statistically significant lower mean IOP level following TRAB than 5-FU (-2.17mmHg; 95%CI -3.26 to -1.08, P<0.001). Subgroup analysis revealed that a significant efficacy benefit was observed with high dose adjuvant MMC (>0.2mg/ml) compared with adjuvant 5-FU but no significant difference was observed between low dose adjuvant MMC (≤0.2mg/ml) compared with adjuvant 5-FU. There was no significant difference in the occurrence of wound leak, persistent hypotony, endophthalmitis, choroidal effusion and decrease in visual acuity of more than two lines between MMC and 5-FU. The MMC group experienced a significantly lower incidence of postoperative corneal epithelial defects than the 5-FU group (4/111 [3.6%] vs. 13/109 [12%] participants; P=0.021). The authors conclude TRAB with MMC is associated with higher rates of surgical success and is not associated with increased postoperative complications compared with TRAB with 5-FU.

Reference

Mitomycin C versus 5-fluorouracil as an adjunctive treatment for trabeculectomy: a meta-analysis of randomized clinical trials.
De Fendi LI, Arruda GV, Scott IU, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2013;41:798-806.

Cornea

Corneal keloid: Report of natural history and Outcome of Surgical Management in Two Cases
Reviewed by: Sharmina Khan
Feb/Mar 2014 (Vol 20 No 5)
 

Corneal keloids are rare and typically reported following trauma (including post-surgical) and has been reported without any trauma or previous surgery. A corneal keloid differs from a hypertrophied scar in that it occurs months/years after the injury, enlarges over time and extends beyond the orders of the original traumatized tissue. They are typically solitary, firm, elevated and well-demarcated from the normal tissue. The authors report two cases with no trauma/surgical history. Case 1 was that of a 21 year old Caucasian man with a five year history of enlarging white opacity on the central cornea, OCT showed only anterior stromal involvement with a defined plane. His uncorrected visual acuity was 20/70 and BCVA 20/20. Superficial keratectomy (SK) was carried out followed by recurrence which was treated with two further SK and PTK with topical Mitomycin 0.02%. Further recurrence confined to the diameter of the excimer laser ablation required a DALK (Femto assisted). Eight months post-op his BCVA was 20/25. Histology showed irregular epithelium overlying anterior lamellar stromal scarring and thick collagen bundles associated with exuberant fibroblastic proliferation consistent with corneal keloid. Case 2 was that of a 24 year old African American man presenting with bilateral corneal opacities which were present since the age of seven and grew dramatically in the preceding two years. He underwent bilateral SK at the age of nine years with rapid recurrence. At the age of 13 he underwent PK in the left eye with dense recurrence two weeks post-operatively. He became legally blind for 11 years and developed sensory deprivation nystagmus and underwent Boston K pro type 1 (for blinking eye with no cicatrisation or lid abnormalities) including intra-operative lensectomy and vitrectomy. Three months post-operatively his uncorrected VA was 20/20 with recurrence to the edge of the keratoprosthesis titanium front plate. Histology showed coarse collagen bundles, granulation tissue and fibroblasts consistent with corneal keloid. Keloids have also been described congenitally in association with Lowe’s syndrome. The differentials are Salzmannoid nodular degeneration, Peter’s anamoly and fibrous hystiocytoma in addition to conditions causing diffuse corneal oedema. Histology usually shows a thickened corneal epithelium, overlying an anterior stroma with irregularly arranged collagen bundles, with activated fiboblasts and myofibobalsts which later become hyalinised collagen. Hypertrophied scar tissue involves subepithelial tissue and the collagen bundles are less haphazard and less hyalinized. Some have hypothesized that keloids and hypertrophic scars represent successive stages of the same condition driven by an inflammatory process. It is interesting to note that the front plate of the Boston K-pro type 1 appears to have halted the margin of recurrence in the second case and the authors comment that this should be considered as the primary corneal procedure in such cases. It would certainly be worth considering following recurrence after repeat SKs as an alternative to a penetrating or lamellar keratoplasty.

Reference

Corneal keloid: Report of natural history and Outcome of Surgical Management in Two Cases
Bakhtiari P, Agarwal DR, Fernandez AA, Milman T, Glasgow B, Starr CE, Aldave AJ.
CORNEA
2013;32(12):1621-4

Cornea

Fellow eye comparison of DMEK and PKP
Reviewed by: Sharmina Khan
Feb/Mar 2014 (Vol 20 No 5)
 

This retrospective analysis of 11 patients who underwent penetrating keratoplasty (PKP) in their first eye followed by descemet membrane endothelial keratoplasty (DMEK) in their second eye studied visual and refractive outcomes. Intra and postoperative complications were compared and a subjective questionnaire to evaluate patient satisfaction is reported. In all cases the indication for surgery was Fuchs’ endothelial dystrophy. Visual acuity (VA) improved compared to preoperatively in both groups but in the DMEK group was significantly higher at the last follow-up. The mean manifest spherical equivalent and manifest cylinder were higher in those who underwent PKP than those who underwent DMEK. Eyes that underwent PKP demonstrated higher levels of higher order aberrations than DMEK patients. In terms of complications five cases of DMEK required additional intracameral air injection. In one case of DMEK there was raised intraocular pressure (IOP) one day post op. In two eyes with PKP resuturing was required and in one case a suture was placed for high astigmatism. In the questionnaire survey nine out of 11 patients evaluated their visual outcome post-surgery as being superior in the DMEK eye than the PKP eye. Visual outcomes were graded significantly higher. Four patients stated DMEK was more painful than PKP. There was no statistical difference in pain scores between the two procedures. Two patients complained of no significant improvement in VA after undergoing PKP. Mean patient satisfaction was significantly higher in the DMEK eyes as the mean recovery period was significantly greater in the PKP group. Ten out of 11 patients preferred DMEK, citing the use of general anaesthesia versus local anaesthesia as the deciding factor. The sample size is small in this study and there may be a recall bias in the patient questionnaire as the follow-up times for the two procedures are so different. However, the trend towards posterior lamellar surgery for Fuchs’ endothelial dystrophy is already set and more is being reported about the advantages. DMEK is a more challenging procedure than Descemet’s stripping automated endothelial keratoplasty (DSAEK) and most corneal graft surgeons in the UK are still doing DSAEK as the results of this are superior to PKP.

Reference

Fellow eye comparison of descemet membrane endothelial keratoplasty (DMEK) and penetrating keratoplasty (PKP).
Maier A-K B, Gundlach E, Gonnermann J, et al.
CORNEA
2013;32:1344-8.

Current Eye Research

Ginko bilboa extract affects hypoxic retinal pigment epithelial cells
Reviewed by: Khadijah Basheer
Feb/Mar 2014 (Vol 20 No 5)
 

Wet age-related macular degeneration (AMD) is characterised by choroidal neovascular membrane (CNVM) formation. It is thought that localised hypoxia within the retina results in overexpression of growth factors such as vascular endothelial growth factor (VEGF), which induces CNVM formation. VEGF expression is enhanced by hypoxia in cultured retinal pigment epithelium (RPE) and photoreceptor cells. VEGF expression increases via several mechanisms but is largely mediated by hypoxia-inducible factor-1 (HIF-1). VEGF expression in cultured hypoxic RPE cells is inhibited by the interference of HIF-1a messenger RNA (mRNA). In laser induced CNVM HIF-1a knockout mice the disruption of HIF-1a in RPE attenuated the overexpression of VEGF. Ginko bilboa extract (GBE) is already established in improving blood flow and has been widely used in a variety of disorders including dementia and peripheral vascular disease. A study demonstrated recently that GBE inhibited cell death of cultured RPE cells under hypoxic conditions. This study investigated the effects of GBE on HIF-1a and VEGF expression in cultured human RPE cells in hypoxic conditions. RPE cells were cultured into three different groups; untreated control group, hypoxic group and hypoxic group with GBE. The groups were then analysed at different time points for expression of HIF-1a and VEGF. HIF-1a and VEGF mRNA were quantified using real-time polymerase chain reaction (PCR) and nuclei using enzyme linked immunosorbent assay (ELISA). In the hypoxia group levels of HIF-1a mRNA, VEGF mRNA, HIF-1a and VEGF levels were higher compared to the control group. In addition levels of HIF-1a mRNA and VEGF mRNA were also reduced. ELISA testing showed decreased HIF-1a and VEGF protein concentrations in this group. These results are encouraging and further studies would be needed to truly determine the beneficial effects of GBE regarding AMD. This study was an in vitro experiment using cells and therefore the clinical effect of GBE should be judged carefully. It is also unclear how much GBE consumption would have an effect and caution should be taken before encouraging increasing vitamin and mineral supplements for patients, as like medicines they too have adverse side-effects.

Reference

Effects of Ginko bilboa extract on cultured human retinal pigment epithelial cells under chemical hypoxia.
Oh JH, Oh J, Togloom A, et al.
CURRENT EYE RESEARCH
2013;38(10):1072-82.

Experimental Eye Research

Enzymatic clearance of anterior chamber infiltrate in uveitis
Reviewed by: Graham Wallace
Feb/Mar 2014 (Vol 20 No 5)
 

Aqueous humour (AH) which fills the anterior chamber (AC) of the eye provides nutrients to the cornea and the lens. Clearance of cellular and particular matter from AH is necessary for good visual acuity. In part this is achieved by high turnover of AH production by the ciliary body and removal via the trabecular meshwork. Moreover, the tissues surrounding the AC, corneal epithelium, ciliary body epithelium and trabecular meshwork all have phagocytic activity. An enzyme lysosomal phospholipase A2 (LPLA2) is ubiquitously present in tissues, and particularly in phagocytic cells such as macrophages. LPLA2 is a secreted protein and is found in many extracellular fluids. In this paper, Hiraoka et al. established endotoxin-induced uveitis (EIU) by subcutaneous injection of lipopolysaccharide in rats. This leads to AC inflammation with cellular and protein infiltrate. LPLA2 activity was significantly increased in AH from rats with EIU and correlated with the extent of inflammation. There was no increase in activity in the serum or cerebrospinal fluid (CSF) of these animals. Immunohistochemistry showed that it was tissue macrophages that expressed LPLA2, and increased migration of these cells may explain the increased enzymatic activity. AH from individuals undergoing cataract surgery including some with uveitis. LPLA2 activity was greater in those patients with uveitis compared to those without. Controlling inflammation in the eye is a complex process particularly in response to infection. While the immune system is required to eliminate pathogens it can also do damage. Increased LPLA2 activity during inflammation gives another mechanism by which the processes of protection and resolution can be mediated.

Reference

Increase of lysosomal phospholipase A2 in aqueous humor by uveitis.
Hiraoka M, Abe A, Lennikov A, et al.
EXPERIMENTAL EYE RESEARCH
2014;118:13-9.

Eye

Chronic drop use and trabeculectomy on tear osmolarity
Reviewed by: John Brookes
Feb/Mar 2014 (Vol 20 No 5)
 

Ocular surface disease (OSD) is common in patients chronically treated for glaucoma. This may be related to the drug itself but often to the preservatives in the medication. Much work has been done on the most common preservative, benzalkonium chloride (BAK). The preservatives cause microbial cell destruction by disrupting the cell membrane lipids and cytoplasmic contents. The lipid-destruction properties of BAK also affect the tear lipids responsible for the stabilisation and evaporation control of the tear film; its disturbance being a major cause of dry eye. This paper describes a prospective, case-controlled study of 130 participants, including normal controls, glaucoma patients on chronic preserved anti-glaucoma medication and post-trabeculectomy patients not on medication for over six months. Compared with normal controls, both groups of glaucoma patients were more likely to have a raised tear film osmolarity (TFO), with an odds ratio of 4.43 and 2.76 respectively. Both groups of glaucoma patients were also more likely to have dry eye symptoms. The authors conclude that TFO is increased in glaucoma patients on chronic topical medications and remains elevated after trabeculectomy surgery. They suggest further studies may be warranted to determine whether dry eye is merely aggravated by or can be caused by trabeculectomy surgery. It will be interesting to see what effect the increasing use of non-preserved eye drops has on TFO and symptoms of dry eye.

Reference

Effect of chronic anti-glaucoma medications and trabeculectomy on tear osmolarity.
Lee S-Y, Wong TT, Chua J, et al.
EYE
2013;27:1142-50.

Investigative Ophthalmology and Visual Science

Glasses or not?
Reviewed by: Carmel Noonan
Feb/Mar 2014 (Vol 20 No 5)
 

In this excellent review article, the authors discuss how some hyperopes avoid strabismus but also ask why the youngest infants escape strabismus and older patients go on to decompensate. The review considers a number of related aspects and their inter-relations including: the development of accommodation, the development of vergence and the development of refractive error. The authors conclude from their review of the literature that infants have active accommodation and vergence responses established commonly by three to six months of age. However, in order to improve prevention of strabismus development, it is important to improve our understanding of how individuals manage combined accommodation and vergence motor responses and how individuals avoid development of strabismus despite presence of risk factors such as family history and refractive error.

Reference

Why do only some hyperopes become strabismic?
Babinsky E, Candy TR.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2013;54:4941-55.

Investigative Ophthalmology and Visual Science

Walking with prisms
Reviewed by: Carmel Noonan
Feb/Mar 2014 (Vol 20 No 5)
 

This study was undertaken to assess which tempero-spatial properties of gait are influenced by vertical yoked prism (VYP) wear and consider any adjustments to gait made to maintain stability both during and following VYP wear. Thirty-one healthy adults were recruited. Three prism conditions were tested: 5PD base up, 5PD base down, plano. The results showed significant changes in gait patterns while wearing base down prisms with slowed velocity, reduced cadence, shortened step length, increased double support phase and increased step tone variability. These effects were not seen in the base up condition. The only change seen for base up prisms was a narrowed step width. Many reported feeling taller with base down prisms and this could lead to fear of falling and therefore could result in moving with greater caution and hesitancy. Floor perception was of a slanting upwards and away floor with base down prisms and slanting downwards with base up prisms. No difference was seen for measures on repeated assessment after longer term wear apart from a small increase in step length.

Reference

The effects of vertical yoked prisms on gait.
Errington JA, Menant JC, Suttle CM, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2013;54:3949-56.

Journal of Pediatric Ophthalmology and Strabismus

Comparison of vision screeners
Reviewed by: Fiona Rowe
Feb/Mar 2014 (vol 20 No 5)
 

The primary purpose of this study was to calibrate the various paediatric photoscreeners over a range of contact lens induced hyperopic and astigmatic anisometropia using the American Association of Paediatric Ophthalmology and Strabismus (AAPOS) criteria for anisometropic or axial astigmatism. They applied the AAPOS validation guidelines. Photoscreeners included Nikon retinomax, Suresight, MTI, Gateway DV-S20, Canon TXI, iphone 4S, Plusoptix S09, SPOT and iScreen 3000. All seven photoscreeners gave passing, normal results for emmetropia but referred both cases with contact lens induced anisometropic hypermetropia of 2D and 1.75D induced axial astigmatism. The photoscreen images, remote autorefractors and computer interpreted photoscreeners provide a near linear relationship between induced refractive error and DCC. Iphone, SPOT and iScreen over referred contact lens induced 1D spherical anisometropia. Remote autorefractors had low sensitivity at high specificity with VIPs criteria. All nine objective screeners provided results to sort cases with refractive error in the normal range from those with amblyogenic refractive errors.

Reference

Calibration and validation of nine objective vision screeners with contact lens-induced anisometropia.
Arnold RW, Davis B, Arnold LE, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:184-90.

Journal of Pediatric Ophthalmology and Strabismus

GA position of eyes
Reviewed by: Fiona Rowe
Feb/Mar 2014 (Vol 20 No 5)
 

The authors assessed eye position based on the corneal reflex position (Hirschberg test) using a standardised measurement on pictures taken at the preoperative evaluation and under general anaesthesia (GA) in 41 patients. The mean ocular deviation taken at the preoperative visit was 32.3±11.4 with alternate prism cover test at 40cms and 33.5±12.5 with Hirschbergs. This changed to 8.8±11.4 under GA. Ocular deviation change decreased as patient age increased. Change was positively correlated with preoperative ocular deviation.

Reference

Determinants of ocular deviation in esotropic subjects under general anaesthesia.
Daien V, Turpin C, Lignereux F, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:155-60.

Journal of Pediatric Ophthalmology and Strabismus

Non-accidental retinal haemorrhages
Reviewed by: Fiona Rowe
Feb/Mar 2014 (vol 20 No 5)
 

The authors sought to determine whether the presence of retinal haemorrhages (RH) correlated positively to individuals who confessed to shaking (group a) compared to those who did not confess but were identified as the likely perpetrators (group b) and cases where there was no identified perpetrator (group c). Forty-eight cases were reviewed. RH were reported in 16/18 cases in group a, 12/16 for group b and 6/14 for group c. The total incidence for RH was 73%. There was no significant difference between groups for those who confessed versus those who did not but a significant difference for when the perpetrator was identified versus not. Victims with non identified perpetrators were less likely to present acutely and time may have elapsed allowing RH to recover.

Reference

Incidence of retinal haemorrhages in abusive head trauma.
Gaffer MA, Esernio-Jenssen D, Kodsi SR.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:169-72.

Journal of Refractive Surgery

Rotational stability of angle supported phakic IOL
Reviewed by: Amit Patel
Feb/Mar 2014 (Vol 20 No 5)
 

The authors evaluate 50 eyes of 28 patients that underwent an angle fixated phakic intraocular lens (IOL) implantation (Acrysof Cachet). All eyes had moderate to high myopia (-5.25 to-19.63 dioptres) and IOL sizing was performed as per the manufacturer’s recommendation. All eyes had digital photography to assess IOL position at 0 and 12 months postoperatively. There were no intraoperative complications. Only one eye required additional laser refractive correction. A mean IOL rotation of 11.4±15.1 (range 0 to 60) was noted at 12 months compared to the initial assessment at 0 months. IOL rotation was not associated with endothelial cell loss (which remained stable after three months postoperatively). This study shows a larger rotation than previously reported in other studies and the authors suggest that this may be due to less effective methods of rotational stability assessment by others. The authors stipulate that rotation may be related to pupil movement and accommodation and also suggest that ultrasound biomicroscopy may be useful in assessing eyes with greater IOL rotation. They conclude that this design of the cachet lens would not be suitable for toric correction due to its higher rotational instability.

Reference

Rotation stability of the cachet angle-supported phakic intraocular lens.
Kermani O, Oberheide U, Gerten G.
JOURNAL OF REFRACTIVE SURGERY
2013;29(6):390-4.

Neuro-Ophthalmology

Differential diagnosis of inflammatory optic neuritis
Reviewed by: Claire Howard
Feb/Mar 2014 (Vol 20 No 5)
 

The authors present the differential diagnosis of inflammatory optic neuritis (ON) to include multiple sclerosis, infectious optic neuritis, systemic disease and neuromyelitis optica (NMO). The features of ON for the varying aetiologies are detailed including incidence and overlap. In acute demyelinating ON, patients typically present with progressive unilateral visual loss of variable severity, usually associated with pain. Optic neuritis due to infection more frequently corresponds to neuroretinitis rather than typical ON. ON due to NMO is often more severe and bilateral in nature. ON due to systemic disease has a low incidence reported in reviewed literature. Differentiation between causes is essential for therapeutic and management decisions to be made. A study was performed on 62 patients with relapsing ON and an eight year follow-up period reported. In this group of patients with recurrent ON, two groups had a poor prognosis (high risk of NMO and chronic relapsing inflammatory ON) that may be treated early with immunosuppressive treatments.

Reference

Inflammatory optic neuritis: from multiple sclerosis to neuromyelitis optica.
de Seze J.
NEURO-OPHTHALMOLOGY
2013;37(4):141-5.

Ocular Immunology and Inflammation

Coeliac disease and anterior scleritis
Reviewed by: Saruban Pasu
Feb/Mar 2014 (Vol 20 No 5)
 

The authors present an interesting case report of recurrent anterior scleritis. Circulating IgA and IgG auto-antibodies directed against tissue transglutaminase, endomisium and gliadin are frequently elevated in patients with coeliac disease. The classic symptoms remain chronic diarrhoea, malabsorption syndromes and abdominal discomfort, but there are also rarer systemic findings, including aphthous stomatitis and dermatitis herpetiformis. There is case report evidence of an association between coeliac disease and recurrent or chronic uveitis. The patient described is a healthy 37-year-old woman who was referred to clinic for management of recurrent refractory scleritis in her right eye of unknown aetiology. Her first episode in 2007 resolved with topical steroid treatment. Her second episode a year later needed treatment with oral steroids. She was found to have normal autoimmune blood tests. In 2009 she was first seen in the clinic with recurrence of right eye pain despite being on topical treatment. She also reported recurrent gastrointestinal upset. She underwent examination and extensive testing, including normal digestive endoscopy, colon biopsy and abdominal magnetic resonance imaging. As she had become asymptomatic, tapered withdrawal of the steroid drops was planned. In 2010 she presented with a new recurrence needing high dose oral steroids. She could not tolerate methotrexate or azathioprine so was started on salazopirine. Despite this her inflammation and ocular pain remained. As she continued to complain of recurrent gastrointestinal symptoms, she was once again screened for gastrointestinal diseases in 2011 when high anti-transglutaminase IgA antibodies were found and hydrogen breath test with d-xylose was positive. She was prescribed a strict gluten-free diet, which relieved her ocular and gastrointestinal symptoms. Systemic steroids were slowly tapered and discontinued. Since starting the gluten free diet she has only had one flare of ocular pain, which she puts down to inadvertent exposure to gluten. The authors speculate that an association may be mediated by the intrascleral deposition of immune complexes leading to tissue inflammation, similar to the pathogenesis of dermatitis herpetiformis where dermal intrapapillary deposition of IgA leads to neutrophil infiltration. Coeliac disease should be considered in the differential diagnosis of scleritis associated with gastrointestinal symptoms.

Reference

Anterior scleritis and coeliac disease: a proposed association.
Keller J, Torres-Torres R, Sainz de la Maza M.
OCULAR IMMUNOLOGY AND INFLAMMATION
2013;21(5):410-2.

Ophthalmic Research

Microperimetry of subretinal drusenoid deposits
Reviewed by: Bheemanagouda Patil
Feb/Mar 2014 (Vol 20 No 5)
 

Subretinal drusenoid deposits (SDD), originally termed ‘reticular pseudo-drusen’, have recently been identified by histology and optical coherence tomography (OCT) as aggregations located in the subretinal rather than the sub retinal pigment epithelium (RPE) space. These deposits affect the amount of light reaching the deeper layers. Spectral domain OCT (SD-OCT) shows disruption of inner segment / outer segment (IS / OS) band, which has been suggested to carry prognostic implications. This study evaluates the correlation between light sensitivity and SDD as measured with microperimetry. Twenty-one consecutive patients / eyes with SDD only were included in the study along with twenty patients / eyes in the control group. The control group had early macular degeneration in at least one eye. In all cases best corrected visual acuity (BCVA), colour fundus photography, fundus autofluorescence and SD-OCT with integrated microperimetry were performed. The mean BCVA in the SDD group was 0.18±0.14 LogMAR and the mean BCVA in the control group was 0.16±0.15 LogMAR. In eyes with SDD, the overall mean light sensitivity in the central macula (4.21± 2.46 dB) was significantly reduced when compared to the control group (6.81±2.12 dB). Correlation between BCVA and mean light sensitivity in the central 7x7mm square was low in the SDD group (Pearson’s rho = 0.4, p=0.01), while it was good in the control group (Pearson’s rho = 0.7, p=0.001).

Reference

Microperimetry of subretinal drusenoid deposits.
Forte R, Cennamo G, Crecchio G, Cennamo G.
OPHTHALMIC RESEARCH
2014;51(1):32-6.

Ophthalmology

Combined anti-VEGF and PDT for wet AMD
Reviewed by: Brian Ang
Feb/Mar 2014 (Vol 20 No 5)
 

The authors report on a retrospective case series of combined anti-VEGF and photodynamic therapy (PDT) in the treatment of wet age-related macular degeneration (AMD) refractory to anti-VEGF monotherapy alone. The criteria for treatment failure of anti-VEGF monotherapy were persistent subretinal fluid or retinal thickening of more than 250 microns on OCT at every time point before PDT and a minimum of three intravitreal injections of anti-VEGF therapy over the previous seven months. All subtypes of choroidal neovascular membranes were included. Patients with subretinal fibrosis, retinal pigment epithelium atrophy, previous retinal laser, and choroidal neovascularisation not related to AMD were excluded from the study. The combined therapy consisted of intravitreal anti-VEGF injection (bevacizumab or ranibizumab) followed by half fluence PDT (300mW, 25J, 83 seconds) with verteporfin within seven days. Visual acuity improved significantly at one month and three months, and showed a trend towards improvement at six months. Retinal thickness decreased significantly at one, three and six months. The interval between treatments increased from once every 1.6 months to once every 2.7 months with combination therapy. No ocular complications were seen with combination therapy. This study, although limited by its retrospective study design and small sample size, shows promising results for the treatment of wet AMD that is non-responsive to anti-VEGF therapy. Larger scale and longer term studies are needed to investigate this further.

Reference

Combination therapy for neovascular age-related macular degeneration refractory to anti-vascular endothelial growth factor agents.
Tozer K, Roller AB, Chong LP, Sadda SV, et al.
OPHTHALMOLOGY
2013;120:2029-34.

Ophthalmology

Scheimpflug vs. OCT in measuring corneal thickness
Reviewed by: Brian Ang
Feb/Mar 2014 (Vol 20 No 5)
 

The authors report on the reproducibility and repeatability of corneal thickness measurements using three different Scheimpflug imaging cameras (Pentacam, Sirius and Galilei) and one Fourier-domain optical coherence tomography (OCT) system (RTvue-100). The rationale for this study is that corneal thickness measurements using ultrasonic pachymetry are not entirely reliable due to the requirement for contact with the cornea and dependence on operator skill. The four different instruments stated above all offer the possibility of non-contact corneal thickness measurements, not just at the centre, but also at the mid-periphery and periphery. The study was designed in a way to evaluate the intraobserver variability, interobserver variability and intersession variability for these four instruments. Sixty-six eyes from 66 healthy subjects were recruited for the study. In terms of intraobserver repeatability, interobserver repeatability and intersession repeatability, the Galilei performed best while the Pentacam performed worst. Overall, the repeatability and reproducibility was high for all four instruments at all corneal areas measured apart from the mid-peripheral superior quadrant. The authors did not compare these corneal measurements versus measurements taken by ultrasonic pachymetry, and so agreement could not be evaluated. Nevertheless, this study shows that these imaging methods can provide non-contact corneal thickness measurements that are highly repeatable and reproducible.

Reference

A comparison between Scheimpflug imaging and optical coherence tomography in measuring corneal thickness.
Huang J, Ding X, Savini G, Pan C, et al.
OPHTHALMOLOGY
2013;120:1951-8.

Ophthamology

Four year outcomes of macular degeneration treated with ranibizumab
Reviewed by: Brian Ang
Feb/Mar 2014 (Vol 20 No 5)
 

The authors report on a retrospective study of neovascular age-related macular degeneration (AMD) patients treated with a variable ranibizumab dosing regimen over a period of four years (from January 2007 to December 2011). A total of 600 treatment naïve eyes of 555 patients aged 50 years or older, vision of 0.05 or better and foveal involvement were included in the study. Upon diagnosis, three 0.5mg ranibizmuab intravitreal injections were administered at intervals four weeks apart. The third injection was followed by a clinical examination one month later. If there was activity from the neovascular AMD, intravitreal ranibizumab was administered one at a time. If there was no further activity, follow-up was scheduled four to six weeks later, and then extended to eight to 12 weeks. Patients were discontinued from treatment if there was no AMD activity after six to seven months of observation, or if there was a lack of treatment response or if vision remained persistently <0.05. As expected, the mean vision improved from 0.24 at baseline to 0.18 at four years. Overall, 408 eyes of 381 (around two thirds) patients had treatment discontinued, mainly due to poor vision (169 eyes; 28.2%) followed by inactivity (120 eyes; 20.0%). Of the 120 eyes with discontinued treatment due to disease inactivity, only 20 (16.7%) were referred back due to disease activity, by which time vision had decreased significantly from 0.38 to 0.15. A total of 7,584 injections were given, with the mean number of injections being 5.5 per year. The ocular complication rate was low at 0.2%, with serious complications occurring in only three eyes – one rhegmatogenous retinal detachment and two infective endophthalmitis. In terms of the fellow eye, one third needed treatment during the four year period. This study reaffirms the successful outcomes of ranibizumab injections for neovascular AMD in an as-required model that resembles what happens clinically in most hospitals.

Reference

A 4-year longitudinal study of 555 patients treated with ranibizumab for neovascular age-related macular degeneration.
Rasmussen A, Bloch SB, Fuchs J, et al.
OPHTHALMOLOGY
2013;120:2630-6.

Ophthamology

Modern trabeculectomy outcomes
Reviewed by: Brian Ang
Feb/Mar 2014 (Vol 20 No 5)
 

This audit was conducted by the Trabeculectomy Outcomes Group Audit Study Group to report on the efficacy and safety of current trabeculectomy surgery in the UK. This is relevant in light of the fact that the trabeculectomy outcomes presented by the UK National Trabeculectomy Survey were based on data collected 15 years ago, and thus in need of being updated. The evolution of glaucoma surgery over the past two decades has been immense, and includes the increasing use of intraoperative mitomycin C, releasable and adjustable sutures and postoperative 5-fluorouracil (5-FU) injections, which have all purportedly contributed to safer surgery with less postoperative complications. The audit looked at trabeculectomy outcomes of 428 eyes of 395 patients with primary open angle or pseudoexfoliation glaucoma. At the end of two years, the mean intraocular pressure (IOP) had reduced from 23mmHg preoperatively to 12.4mmHg. IOP of 18mmHg or less and 20% reduction of preoperative IOP was achieved without any IOP-lowering medications in 78% and with medications in 86%. Many eyes required post-trabeculectomy interventions, such as suture manipulation (43%), postoperative 5-FU injections (28%) and bleb needling (17%). The commonest postoperative complication was bleb leak (14%) followed by bleb encystment (7.7%). Hypotony (3%) was relatively uncommon, as was bleb-related infection (1%). The results of this survey confirm that with the current modern surgical techniques, trabeculectomy outcomes have improved, with better IOP control and lower rates of serious complications, although this was associated with the need for intensive proactive postoperative care.

Reference

Trabeculectomy in the 21st century – a multicenter analysis.
Kirwan JF, Lockwood AJ, Shah P, et al.
OPHTHALMOLOGY
2013;120:2532-9.

Strabismus

Impact of orthoptic re-exam in screening
Reviewed by: Fiona Rowe
Feb/Mar 2014 (Vol 20 No 5)
 

The authors evaluated whether the re-examination within the orthotic screening in children with questionable results at the first examination can reduce the number of submissions to specialists and avoid a high number of false positives. This was a retrospective study of screening data for 2010 of 7,772 children. Six thousand one hundred and twenty-six attended screening and 1,646 did not attend. Of the latter, 318 had already been examined elsewhere. Of 6,126 examined, 5,137 were negative, 562 had a positive result and were referred, 427 showed unreliable results and were invited for a second screen. At the second screen, only 120 were positive and 307 were now negative. Most were aged three years and lack of cooperation may be a contributing factor. The second screen reduced false positives

Reference

The pediatric vision screening program performed in Bolzano in 2010: significance of the orthoptic re-examination.
Bottin D, Waldhauser K, Bertelli E.
STRABISMUS
2013;21:81-4.

Strabismus

Photoscreening comparison
Reviewed by: Fiona Rowe
Feb/Mar 2014 (Vol 20 No 5)
 

The A09/S09 photoscreener contains a fixation target of flashing lights (as for the S04) plus a smiley face which is new. Concerns were raised that the smiley face may stimulate less accommodation than the S04 attention lights and therefore potentially underestimate hypermetropia. The authors sought to determine if the referral pattern of the A09 was consistent with that of the S04 using the same pre-programmed referral criteria. One hundred and thirteen children aged less than one year up to 11 years (average five years) were examined. No significant difference was found in the pass / refer pattern of results. Correlation was 0.8345. There was no significant difference for sensitivity, specificity, false positive or false negative rate between the two devices. They conclude the S04 and A09/S09 are validated and useful tools for visual screening programmes.

Reference

A comparison of the Plusoptix S04 and A09 photoscreeners.
Singman E, Matta N, Tian J, et al.
STRABISMUS
2013;21:85-7.

Strabismus

Quality of esotropia referrals
Reviewed by: Fiona Rowe
Feb/Mar 2014 (Vol 20 No 5)
 

The purpose was to examine the quality of referrals made for children with esotropia and to evaluate management offered prior to referral. This retrospective study identified 326 children with esotropia aged less than five years and referred over a period of three years. Two hundred and seven were referred by optometrists and 119 by physicians. The mean delay in referral was 17.82 months for referrals made by physicians and 24.64 months for optometry referrals which was a significant difference. Twenty-one percent of all referrals were within four months of onset of esotropia. Twenty-one percent were for infantile esotropia and 48% of these had stereopsis of 100” or better. Management for refractive error and amblyopia was not always instigated prior to referral. Where management was offered prior to referral, it was not always appropriate or adequate in more than 50% of cases. Local education and information is required to improve referrals

Reference

Quality of referrals to a pediatric ophthalmology practice in South Western Ontario.
Makar I, Kerrin M, Smith K.
STRABISMUS
2013;21:88-92.

Strabismus

Saccadic differences under cover test
Reviewed by: Fiona Rowe
 

Patients with intermittent exotropia and exophoria plus ortho subjects underwent measurement of saccadic reaction times (SRTs) to compare those occurring in one eye and those occurring with alternating cover tests (ACTs). Twenty-five subjects were studied. Results for the intermittent exotropia group showed SRTs for ACT task of 227.3±69.9ms, and for normal task of 185.4±54.1ms. Results for the exophoria group showed SRTs for ACT task of 198.45±45.3ms, and for normal task of 178.2±34.6ms. Results for the ortho group showed SRTs for ACT task of 224.2±46.5ms, and for normal task of 200.7±37.8ms. The ACT task results were significantly prolonged in all groups. In each group a significant increase in SRTs occurred for the ACT task compared to normals. Further increase was seen for the strabismus group compared to ortho. The authors propose that the influence of occlusion of the re-fixating eye on the release of fixation attention may cause the lag of response.

Reference

Saccadic reaction times in alternating cover.
Shinomiya Y, Yamada T, Suzuki K, et al.
STRABISMUS
2013;21:74-7.

Strabismus

Translucent vs. lightproof occluders
Reviewed by: Fiona Rowe
Feb/Mar 2014 (Vol 20 No 5)
 

This study investigates the change in visual acuity following occlusion in amblyopes and non-amblyopes using translucent versus lightproof occlusion of the dominant eye. Group 1 non-amblyopes consisted of 26 subjects: 16 visually normal and 10 strabismic or anisometropic subjects without amblyopia. Group 2 amblyopes consisted of 33 subjects: 14 strabismic, six anisometropic and 13 mixed amblyopes. The results indicate that the use of lightproof or translucent occlusion over the dominant eye during visual acuity testing of the non-dominant eye had no significant effect when comparing large groups of amblyopes and non-amblyopes and within each group. They found no overall detriment to using dark occlusion or improvement with translucent occlusion. However, a number of subjects in each group had an interocular effect of up to 0.15 logMAR. An increase was seen in interocular effect with eso deviations and abnormal retinal correspondence. Anisometropic amblyopia showed monocular improvement with lightproof occlusion. Strabismic amblyopia showed monocular improvement with translucent occlusion.

Reference

Interocular effect during visual acuity measurement with and without amblyopia.
Parkinson J, Sandusky H, Trembley F.
STRABISMUS
2013;21:67-73.

Acta Ophthalmologica

Density of cataract and its influence on retinal nerve fibre layer thickness
Reviewed by: Dr Nana Theodorou
Dec/Jan 2013 (Vol 20 No 4)
 

The aim of this study was to further define and model the influence of cataract on spectral domain optical coherence tomography (SDOCT) image quality and retinal nerve fibre layer (RNFL) thickness measurements. OCT quality is influenced by opacities in the optical path and cataracts in the elderly can potentially affect OCT images. The more advanced the cataract the thinner the recorded RNFL thickness. In this study, SDOCT images were taken with two different devices (3DOCT-1000 and Cirrus HD-OCT) before and after cataract surgery and compared against normal participants using artificial filters simulating a cataract effect. Forty eyes with cataract were included and OCT image quality improved significantly postoperatively as well as RNFL thickness. The measurements using the artificial filters showed a linear relation in filter induced optical density and change in RNFL thickness. The findings may have clinical implications in diagnosing glaucoma patients with known cataract using the OCT.

Reference

The relationship between the optical density of cataract and its influence on retinal nerve fibre layer thickness measured with spectral domain optical coherence tomography.
Kok PHB, van den Berg TJTP, van Dijk HW, et al.
ACTA OPHTHALMOLOGICA
2013;91:418-24.

American Journal of Ophthalmology

Cataract surgery in patients with retinitis pigmentosa
Reviewed by: Mr K C Madhusudhana
Dec/Jan 2013 (Vol 20 No 4)
 

Retinitis pigmentosa (RP) is the commonest inherited cause of retinal degeneration. Posterior subcapsular cataract (PSC) develops in 41% to 90% of these patients by age 40 years. In this retrospective study, the authors have evaluated surgical outcomes in patients with RP undergoing phacoemulsification (n=87 eyes of 47 patients). Data on best-corrected visual acuity (BCVA), lens and zonular status, use of capsular tension ring (CTR), incidence of posterior capsular opacification (PCO) and YAG laser capsulotomy, and surgical complications were recorded. Average age was 48.9 years (range, 31-78 years) with a mean follow-up period of 23.3 months. Most (97.5%) of these patients had PSC. Mean BCVA improved from 20/340 to 20/129 within three months of surgery (p<0.0001). Eyes with a preoperative vision of 20/40 to 20/200 (47 eyes) improved from a mean 20/81 preoperatively to 20/43 (p<0.0001), postoperatively. PCO occurred in 82.5% of cases while YAG capsulotomy was required in 52.5% at an average 10.8 months postoperatively. Signs of phacodonesis were seen in 18.8% of eyes. One patient developed bilateral in-the-bag intraocular lens (IOL) dislocation more than five years after surgery. The authors conclude that cataract surgery improves visual acuity in a majority of RP patients with a preoperative vision of 20/200 or better. However, patients with a preoperative BCVA of 20/400 or worse have limited visual improvement objectively, owing to the macular pathology, but still report noticeable subjective improvement. A high prevalence of zonular weakness is noted in these patients warranting careful evaluation preoperatively and to use appropriate techniques to minimise zonular stress. The placement of standard CTRs alone may not prevent late in-the-bag IOL dislocations and hence alternative means of IOL fixation should be considered in cases with advanced or progressive zonular weakness.

Reference

Cataract extraction outcomes and the prevalence of zonular insufficiency in retinitis pigmentosa.
Dikopf MS, Chow CC, Mieler WF, Tu EY.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2013;156(1):82-8.e2.

British Journal of Ophthalmology

Comparison of bilateral lateral and unilateral recession resection for IXT
Reviewed by: Mr Jonathan Chan
Dec/Jan 2013 (Vol 20 No 4)
 

This is a retrospective review study of patients between the ages of three and 15 years old with the basic type of intermittent exotropia (IXT) who had strabismus surgery between January 2003 to September 2009. There were 85 patients included in the study; 38 had bilateral lateral recti recessions (BLR-rec) and 47 underwent recession resection (R&R) procedure. The inclusion criteria included: basic type IXT within 10 prism dioptres (PD) before and after 60 min monocular occlusion; between the age of three to 15 years old at the time of surgery; no previous history after surgery or Botulinum toxin injections; best corrected visual acuity in the worst eye was at least 20/40 or better and no interocular difference of visual acuity more than two lines; no anisometropia with difference of greater than 2.50D and no hyperopia or myopia greater than +6.000D spherical equivalent in either eye; largest exodeviation at either distance or near between 15 and 50PD by the prism and alternate cover test with appropriate optical correction; no coexisting vertical deviation greater than 5PD or any evidence of A or V pattern. The postoperative follow-up period was at least six months’ duration. Successful alignment was defined as esophoria / tropia, less than or equal to 5PD to exophoria / tropia, less than or equal to 8PD in primary gaze while viewing distant or near targets. The mean follow-up period was 14.8+/- 9.5 months. In the R&R group, there was a significantly high success rate versus BLR-rec group (85.1% vs 65.8%, p=0.037). The undercorrection rate was significantly lower in the recession and resection group than in the bilateral lateral recti recession group (6.4% vs 23.7%, p=0.023). There was no significant difference in the overcorrection rate between the two groups (10.5% vs 8.5%, p=1.000). The authors suggest that the limitations of the study, including the retrospective nature of the study and the sample size is relatively small. Only a minimum follow-up period of six months was included and the reliability of the study of sensory function parameters were not included because of the inability of some of the younger children who could not manage the Worth four dots test and Titmus stereo test.

Reference

Comparison of bilateral lateral rectus recession and unilateral recession resection for basic type intermittent exotropia in children.
Wang L, Wu Q, Kong X, Li Z.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:870-3.

British Journal of Ophthalmology

Short-term outcome after intravitreal ranibizumab injections for ROP
Reviewed by: Mr Jonathan Chan
Dec/Jan 2013 (Vol 20 No 4)
 

This is an interventional case series study of three premature babies (six eyes) with high risk prethreshold or threshold retinopathy of prematurity (ROP) with plus disease that received intravitreal ranibizumab injections for ROP. All infants received intravitreal ranibizumab injections of 0.25mgs/0.025ml (half dose of adult dosage). A 27-gauge needle was used for the intravitreal injection, 1mm from the limbus. The treatment technique required topical anaesthetic, aseptic skin and eye preparation, together with local anaesthesia and insertion of a premature lid speculum. Follow-up examination included day one and seven days after treatment and then this was followed by the first, third and sixth month, and every six months later until the age of three years old. All eyes showed complete resolution of new vessel formation after a single intravitreal injection of ranibizumab. None of the children developed any evidence of recurrence of the disease or progression during the follow-up period. No ophthalmic or other systemic side-effects were found. The authors concluded that further large scale studies of multi-centre randomised trials were required for the long-term safety efficacy of ranibizumab treatment in ROP.

Reference

Short-term outcome after intravitreal ranibizumab injections for the treatment of retinopathy of prematurity.
Castellanos MAM, Schwartz S, Garcia-Aguirre G, Quiroz-Mercado H.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:816-9.

Clinical and Experimental Ophthalmology

Long-term meibomian gland function following a single thermal pulsation treatment
Reviewed by: Dr Kwesi Amissah-Arthur
Dec/Jan 2013 (Vol 20 No 4)
 

Dry eyes secondary to blepharitis and or meibomian gland dysfunction, though extremely common, is an annoyingly difficult condition to treat for several patients. Part of this difficulty lies in the inability of most patients to follow intensive and often times complex eyelid cleaning instructions coupled with a large quantity of artificial tear use to improve the lipid profile of the precorneal tear film. The LipiFlow Thermal Pulsation System was designed to directly tackle meibomian gland dysfunction as this is seen as the root cause of this condition. A device that uses an insulated lid warmer, which resembles a scleral contact lens to vault the cornea and provide controlled heat to the tissues, delivers the thermal treatment. The device also has an eye cup that consists of an inflatable bladder that sits on the eyelid and pulsates to allow expression of the meibomian glands. Heat treatment with pulsation is delivered to the meibomian glands over a 12-minute period. This paper looks at the one-year results of using this new device. Thirty patients with evaporative dry eye disease with meibomian gland dysfunction and dry eye symptoms were recruited for the study, but only 18 were able to return for the one year review. The effectiveness of the device was reviewed by measuring meibomian secretion scores and tear break-up time. Dry eye symptoms were measured using the Ocular Surface Disease Index (OSDI) and the Standard Patient Evaluation of Eye Dryness (SPEED). The authors report a significant improvement in meibomian gland secretion scores from baseline measurements (4.0±3.4) to one month, which were maintained at one year (7.3±4.6; P<0.05). Baseline tear break-up time (4.9±3.0) was significantly increased at one month (9.5±6.9; P<0.05); however, this improvement was no longer evident at one year post-treatment (6.0±4.4). The improvement in symptom scores on Ocular Surface Disease Index and Standard Patient Evaluation of Eye Dryness questionnaires observed at one-month (P<0.0005) was maintained at one year (Ocular Surface Disease Index [P<0.05]; Standard Patient Evaluation of Eye Dryness [P<0.0005]). The authors found no statistically significant difference between right and left eyes, and as such they averaged them for each patient; however, they do not document if a correction was applied or not. This study suggests that it is possible with a single 12-minute treatment of thermal pulsation, to improve some symptoms of meibomian gland dysfunction for up to a year. The study does not mention the cost of the device or cost of treatment, for ophthalmologists to assess whether the cost / benefit analysis is in favour of this treatment or not. Also the authors agree that the device does not tackle all aetiological causes of dry eyes, particularly as dry eye tends to be a multi-factorial condition. There is also concern about the number of dropouts from the surgery, though the authors have made an attempt to explain what happened to the 12 patients lost to follow-up. The main question for the authors will surely be how their device compares to relatively cheap and easily available latent heat devices that are now on the market.

Reference

Long-term (12-month) improvement in meibomian gland function and reduced dry eye symptoms with a single thermal pulsation treatment.
Greiner JV.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2013;41:524-30.

Cornea

Ocular lubrication versus bandage contact lens in recurrent erosion syndrome (RES)
Reviewed by: Ms Sharmina Khan
Dec/Jan 2013 (Vol 20 No 4)
 

Twenty-nine patients (eight traumatic, five epithelial basement membrane dystrophy, two idiopathic) were randomised using SPSS to either ocular lubricants or bandage contact lenses (BCLs). Only patients previously treated with ocular lubricants were included. Patients with previous surgery, laser treatment, dry eye, meibomian gland dysfunction ocular surface disease or previous refractive surgery were excluded. Patients were examined on the slit-lamp and findings recorded; their pain was scored using a visual analogue score. Patients with macro erosion were first treated with g. Chloramphenicol 0.5% 4/day for five days. Patients were examined monthly for four months, if there was resolution again at three months otherwise monthly until seven months. BCLs (Air Optix Night and Day) were replaced monthly. Lubricants used were oc. Lacri-Lube at night and carbomer gel (Celluvisc) 0.5% 4/day. Trial outcome was assessed at four months: 1) Complete resolution with no symptoms; 2) Partial resolution; and 3) No resolution. Results showed no significant difference in outcome at four months between the two treatment arms. However, there was a significant difference in time to resolution; patients on BCL achieved complete resolution at five weeks compared with nine weeks if treated with ocular lubricants. There was no significant difference in the pain scores between the two groups. There is not enough evidence based on this and other studies that routine use of BCL in early RES management is beneficial over ocular lubricants.

Reference

Randomized controlled study of ocular lubrication versus bandage contact lens in the primary treatment of recurrent erosion syndrome.
Anandan MA, Tah V, Dhingra S, Leyland M.
CORNEA
2013;32:1311-4.

Current Eye Research

Association between serum triglycerides and pan retinal photocoagulation in type 1 diabetes
Reviewed by: Dr Khadijah Basheer
Dec/Jan 2013 (Vol 20 No 4)
 

This retrospective cohort study aimed to examine whether dyslipidaemia is a risk factor for progressing to proliferative diabetic retinopathy (PDR) and consequently requiring pan retinal photocoagulation (PRP) treatment in type 1 diabetics. In previous studies including the ETDRS study an association between serum triglyceride and development of PDR in both type 1 and type 2 diabetics has been found. This study looked at the baseline blood tests for cholesterol and lipids for 218 type 1 diabetics and correlated these with how many patients went on to have PRP treatment over a period of 13 years. Patients who had active PDR at baseline were excluded from the study. The results concluded that there is an association between raised serum triglycerides and the incidence of PRP, however, after adjusting for other established risk factors this association was not statistically significant.
Dyslipidaemia is thought to be a contributing factor to diabetic retinopathy and maculopathy and diabetic patients are started on medication to control lipids. The limitations of this study were that the cohort followed over 13 years was relatively small and they did not have any data on whether patients were started on treatment for dyslipidaemia. If the majority of patients had been started on lipid lowering treatments after the baseline lipid blood test this could have had an effect on their severity of diabetic retinopathy. The results from this study demonstrate that serum triglycerides could be an important factor to control in preventing progression of diabetic retinopathy. Ideally further studies on the role of lipids in diabetic retinopathy and the effects of lipid lowering treatments on diabetic retinopathy are needed.

Reference

Long-term associations between serum lipids and pan retinal photocoagulation in type 1 diabetes.
Jorgensen J, Jorgensen T, Green A, et al.
CURRENT EYE RESEARCH
2013;38(8):889-93.

Experimental Eye Research

HtrA1 enhances cell senescence
Reviewed by: Mr Graham Wallace
DEc/Jan 2013 (Vol 20 No 4)
 

A genetic basis for age-related macular degeneration (AMD) has been greatly advanced in recent years. The role of identified pathways such as complement factor H in AMD has been widely investigated. However, the effect of other gene variants identified by genome-wide screens is not so well understood. One such gene is high temperature requirement A1 (HtrA1). HtrA1 encodes a serine protease that has been implicated in protection against cellular stress, and as a tumour suppressor. This study analyses the role of HtrA1 in cell senescence a feature of retinal pigment epithelium (RPE) cells in AMD. Premature senescence was induced in mouse embryonic fibroblasts (MEF) and an RPE cell line (ARPE-19) by treatment with hydrogen peroxide. Expression of senescence markers, such as p16INK4a, were higher in HtrA1 heterozgote MEF compared to deficient cells. HtrA1 WT and heterozygote cells were more resistant to H2O2-induced cell death than deficient cells. Expression of excess HtrA1 led to premature senescence in both MEF and ARPE-19. These results show that HtrA1 is activated by oxidative stress and induces cell senescence as a protective measure. However, chronic stress would lead to an increase in senescent cells in conditions such as AMD driving tissue damage.

Reference

HtrA1 is induced by oxidative stress and enhances cell senescence through p38 MAPK pathway.
Supanji, Shimomachi M, Hasan MZ, et al.
EXPERIMENTAL EYE RESEARCH
2013;112:79-92.

Experimental Eye Research

Nanoparticle administration of latanoprost
Reviewed by: Mr Graham Wallace
Dec/Jan 2013 (Vol 20 No 4)
 

Glaucoma is a progressive optic neuropathy characterised by increased ocular pressure and loss of retinal ganglion cells. Conventional drug therapy with eye drops to reduce intraocular pressure (IOP) has variable bioavailability and can lead to ocular surface disease. In this study poly(lactide)/monomethoxy-poly(ethyleneglycol) (PLA-PEG) nanoparticles (NP) were developed  as a controlled drug delivery system. Latanoprost-loaded NP was administered to the subconjunctival space in rabbits with free LA and empty NP were given to two other groups of animals as controls. Aqueous humour levels of LA were measured by HPLC, and showed the drug released from NP was sustained over 14 day period. LA release from NP induced a significant hypotensive effect while the IOP remained the same in the other groups. No ocular inflammation was seen in the NP treated group. Nanoparticle technology is advancing at a significant rate targeting tumour and immune cells. The use of such systems for slow and controlled release of drug in ocular conditions is a potentially important step forward in treatment of disease.

Reference

Biodegradable nanoparticles for controlled subconjunctival delivery of latanoprost acid: in vitro and in vivo evaluation.
Giarmoukakis A, Labiris G, Sideroudi HA, et al.
EXPERIMENTAL EYE RESEARCH
2013;112;29-36.

Eye

Disc margin delineation using spectral domain OCT
Reviewed by: Mr John Brookes
Dec/Jan 2013 (Vol 20 No 4)
 

Observing progressive anatomical changes of the optic nerve head is essential in the detection of progression in glaucoma. Imaging devices continue to evolve and are useful in detecting change in established glaucoma, although probably less useful in an initial diagnosis. Optic nerve head parameters, such as cup area and volume, rim area and volume and cup / disc ratio, as well as retinal nerve fibre layer (RNFL) thickness, depend on accurate delineation of the optic disc margin. Any displacement of the disc margin may indirectly affect the RNFL thickness. This paper from Bascom Palmer examines the impact of manual versus automated disc margin delineation on optic nerve head (ONH) and RNFL using spectral domain optical coherence tomography (OCT). This prospective, cohort study analysed 99 eyes, of 50 subjects, with established glaucoma, glaucoma suspects and normal individuals. The RNFL thickness measurements were not clinically significantly different between the two methods of demarcation, except in one quadrant (inferonasal). For the ONH measurements, the C/D ratio and rim area showed significant differences between the two methods. The authors conclude, however, that there is high agreement between manual and automated determination for RNFL parameters but greater variation in ONH parameters. RNFL parameters are therefore more robust than ONH parameters for consistent follow-up of glaucoma patients. This study shows that in general, the automated software can reliably delineate the disc margin, compared with manual delineation, especially when assessing RNFL parameters.

Reference

The comparison of manual vs. automated disc margin delineation using spectral-domain optical coherence tomography.
Iverson SM, Sehi M.
EYE
2013;27:1180-7.

Eye

Intensive cataract training
Reviewed by: Mr John Brookes
Dec/Jan 2013 (Vol 20 No 4)
 

Cataract surgery is one of the most commonly performed surgical procedures carried out worldwide but there is a steep learning curve and a higher complication rate for trainee surgeons. This study reports on an innovative training programme of combining the use of surgical simulation followed by an ‘intensive’ period of cataract surgical training, with daily theatre lists. The intensive period in a tertiary centre was followed by a consolidation period in a district general hospital. The training programme begins with wet lab and virtual reality simulation, with trainees completing about 50 hours of structured modules on the simulator. All cases were videoed and complications reported and reviewed with the training programme director. The mean number of theatre sessions required to complete 150 cases was 84. Interestingly, the number of surgical complications was low, with a posterior capsule rupture rate of less than 1%. The authors comment that cataract surgery remains one of the most challenging procedures to master in ophthalmology training and the outcomes are being subjected to increased scrutiny. It is therefore essential to provide good training without compromising patient safety. This pilot shows that intensive surgical training can achieve this, although the challenge now will be to incorporate this as standard, bearing in mind the other factors that ophthalmology services are facing at the moment in combining a service commitment, with the requirements of training.

Reference

Intensive cataract training: a novel approach.
Baxter JM, Lee R, Sharp JAH, Foss AJE.
EYE
2013;27:742-6.

Investigative Ophthalmology and Visual Science

Oral proton pump inhibitors in macular degeneration patients
Reviewed by: Ms Carmel Noonan
Dec/Jan 2013 (Vol 20 No 4)
 

The authors report five patients with advanced wet macular degeneration and poor vision with onset or enhancement of visual hallucinations with the use of proton pump inhibitors for heartburn management. The hallucinations were reversible with discontinuation of medication. The authors propose that proton pump inhibitors may disrupt normal horizontal cell-photoreceptor cell feedback interactions and thereby alter spatial and chromatic perception. The clinical data support the hypothesis that the signals inducing the patterned visual hallucinations are retinal in origin and dependent on activation of the visual transduction cascade. The hallucinations were always noted in bright light and disappeared after 20-30 minutes of darkness. The proposal that visual hallucinations in Charles Bonnet syndrome are related to a loss of neuronal feedback inhibition is consistent with the longstanding concept that hallucinations are release phenomenon that can occur with pathology anywhere in the visual processing pathway.

Reference

Oral proton pump inhibitors disrupt horizontal cell-cone feedback and enhance visual hallucinations in macular degeneration patients.
Hanneken AM, Babaio N, Thoreson WB.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2013;54:1485-9.

Investigative Ophthalmology and Visual Science

The decline in attentional visual fields in the Salisbury Eye Evaluation Driving Study
Reviewed by: Ms Carmel Noonan
Dec/Jan 2013 (Vol 20 No 4)
 

The purpose was to document changes in attentional visual field (AVF) over time and analyse the possible baseline characteristics predicting a decline in AVF size over time. Data was taken from a sample of 968 individuals. The authors found a significant loss of horizontal and average AVF from baseline to two years follow-up. No significant loss of vertical AVF was noted. A greater than five degree decline in AVF score over two years was significantly associated with lower baseline scores of visual search and executive function, visual acuity and visual field, history of stroke and depression at baseline, and being female.

Reference

The decline in attentional visual fields over time among older participants in the Salisbury Eye Evaluation Driving Study.
Rao P, Munoz B, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2013;54:1839-44.

JAMA Ophthalmology

Macular oedema after cataract surgery in diabetic patients
Reviewed by: Lorraine North
Dec/Jan 2013 (Vol 20 No 4)
 

The authors describe a multi-centre prospective observational study of 293 participants that underwent cataract surgery who all had diabetic retinopathy without definite central-involved macular oedema. Forty-five clinical sites took part throughout the United States. Patients were eligible if there was cataract with surgery scheduled within 28 days of recruitment. Central subfield thickening was measured on optical coherence tomography (OCT), if the thickness was less than 250 microns on time domain OCT or less than 310 on spectral domain OCT. Criteria included visual acuity of light perception or better, and presence of microaneurysms on clinical examination. The study showed that 16 weeks after cataract extraction there is an increased risk of developing central involved macular oedema if there is the presence of non-central involved diabetic macular oedema (DME) immediately prior to cataract surgery or any history of previous treatment for DME.

Reference

Macular edema after cataract surgery in eyes without preoperative central-involved diabetic macular edema.
Baker CW, Almukhtar T, Bressler NM, et al.
JAMA OPHTHALOLOGY
2013;131(7):870-9

Journal of Cataract and Refractive Surgery

Corneal biomechanics and refractive outcomes after cataract surgery
Reviewed by: Ms Anju Kadyan
Dec/Jan 2013 (Vol 20 No 4)
 

The authors aimed to study a range of corneal properties and correlate them with refractive outcomes after phacoemulsification. Outcomes were reviewed in a fairly small group of 40 patients (including only right eyes) operated by two surgeons using clear corneal incisions (CCI) of either standard 2.75mm small incision cataract surgery (SICS) or 1.7 and 2.2mm width for co-axial micro-incision cataract surgery (MICS) as per surgeon preference. Corneal thickness increased on day one with corresponding decrease in corneal hysteresis (CH), both recovering to preoperative values at one month. The Corneal Resistance Factor (CRF) showed a significant change from baseline but was reduced more with direct than constructed 3-plane corneal incisions. Surgically induced astigmatism (SIA) was higher in the SICS group and correlated positively with incision width and negatively with CH and CRF (multivariate regression generated equation developed). All higher order aberrations (HOA) increased initially and regained preoperatively value by day 30 except third order trefoil. Literature has not consistently shown a decrease in SIA and HOA with smaller incision size and this study results emphasise the existence of other factors like corneal biomechanics. The findings suggest 3-step CCI are better as they do not weaken corneal resistance and taking the preoperative CH into account helps to better predict the final refractive result.

Reference

Influence of corneal biomechanical properties on surgically induced astigmatism in cataract surgery.
Denoyer A, Ricaud X, Van Went C, et al.
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2013;39:1204-10.

Journal of Glaucoma

Baerveldt Glaucoma Implant (BGI)
Reviewed by: Lorraine North
Dec/Jan 2013 (Vol 20 No 4)
 

The authors describe surgical outcomes using the BGI and compared the  different techniques used. The main differences described in the implantation technique include the use of a prolene stent in the tube, or fixation of the tube to the sclera. A retrospective study of patients that underwent BGI implantation between Sept 2007 and Aug 2008 was undertaken. A total of 173 BGI procedures were performed during this time. Patients were divided into different surgical technique groups and success was defined as intraocular pressure between greater or equal to 6mmHg and less than or equal to 21mmHg after surgery. Other data included the surgeon, surgical implantation (use of prolene stent, fixation of tube to sclera, subconjunctival steroids at the end of the procedure), BGI 250 OR 350mm2, OD/OS, intraoperative complications, and the number and types of anti-glaucoma medications over time. The authors found no differences in the complications or in the success rates between the two surgical techniques. They found the overall complication rates of the BGI implantation were low and the success rates were high in their study population.

Reference

Surgical outcomes of the Baerveldt Glaucoma Implant: differences between surgical techniques in the Rotterdam eye hospital.
Poels MMF, Niessen AGJE, de Waard PWT, Lemij HG.
JOURNAL OF GLAUCOMA
2013;22(5):363-8.

Journal of Glaucoma

Impact of medical vs. surgical treatment on quality of life in glaucoma patients
Reviewed by: Lorraine North
Dec/Jan 2013 (Vol 20 No 4)
 

The author recruited 225 patients across two sites and divided them into three groups. Group 1 medical treatment only, Group 2 surgical treatment only, Group 3 mixed medical and surgical (patients still on drops after surgery). They then used a Brazilian validate version of the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) to assess the patient’s health–related quality of life and also made comparisons among the groups for demographic and clinical characteristics. They found that patients under medical treatment only had better quality of life than those subjected to surgery but this was more evident in the early glaucoma. The advanced cases did not show a negative influence on quality of life scores. The different types of surgery also showed no difference

Reference

Quality of life of medically versus surgically treated glaucoma patients.
Guedes RAP, Guedes VMP, Freitas SM, Chaoubah A.
JOURNAL OF GLAUCOMA
2013;22(5):369-73.

Journal of Glaucoma

Risk factors and untreated POAG
Reviewed by: Lorraine North
Dec/Jan 2013 (Vol 20 No 4)
 

The authors examined 50 untreated open angle glaucoma patients to determine if there was an association between the level of glaucomatous damage and documented risk factors. In this study the authors measured the extent of morphologic and functional glaucomatous damage along with other parameters of ocular blood flow. Any patient with diabetes, untreated or unstable hypertension, hypercholesterolemia, drug or alcohol abuse, significant cataract, narrow angle, secondary glaucoma or smoker were excluded. Intraocular pressure (IOP) was measured using Goldmann applanation tonometry at three time intervals throughout the day. Blood pressure and corneal temperature were recorded. Ocular pulse amplitude was assessed using the Pascal: choroidal blood flow and retinal vessels were analysed using the Retinal Vessel Analyser. Visual fields and optical coherence tomography (OCT) of the retinal nerve fibre layer thickness were also measured. The authors found that more advanced functional glaucomatous damage shown in increased mean deviation on visual fields was associated with lower ocular perfusion pressure and increased IOP variability in untreated patients. More advanced morphologic glaucomatous damage represented by thinner retinal nerve fibre layer (RNFL) was associated with lower blood flow and high IOP in untreated patients. The authors conclude that IOP and perfusion parameters seem to contribute in part to the morphologic and functional glaucomatous damage in untreated primary open angle glaucoma (POAG) patients

Reference

Association between risk factors and glaucomatous damage in untreated primary open-angle glaucoma.
Gugleta K, Polunina A, Kochkorov A, et al.
JOURNAL OF GLAUCOMA
2013;22(6):501-5.

Journal of Glaucoma

Swept source anterior segment OCT
Reviewed by: Lorraine North
Dec/Jan 2013 (Vol 20 No 4)
 

The authors describe a study using the Casia OCT which is a swept source OCT to determine the visibility of the angle structures using two imaging protocols; high density and low density. They randomly selected one eye from 30 normal subjects and 30 primary open angle glaucoma subjects to image. They found high interobserver agreement for assessment of visibility of the angle structures and in particular the scleral spur, swalbes line and schlemm’s canal could all be identified. However, this was dependent on the imaging protocol chosen and the quadrant imaged.

Reference

Anterior chamber angle imaging with swept-source optical coherence tomography: detecting the scleral spur, schwalbe’s line and schlemm’s canal.
McKee H, Ye C, Yu M, et al.
JOURNAL OF GLAUCOMA
2013;22(6):468-72.

Journal of Glaucoma

Time domain vs. spectral domain in the measurement of the optic nerve head
Reviewed by: Lorraine North
Dec/Jan 2013 (Vol 20 No 4)
 

The authors describe a prospective study of 40 participants (20 healthy and 20 with glaucoma) enrolled to compare the measurements of the optic nerve head (ONH) parameters given by time domain (TD) and spectral domain (SD) optical coherence tomography (OCT). Visual field examinations were also carried out using SITA standard 24-2. Cirrus HD-OCT ONH imaging was then carried out using the optic disc cube. A second operator then performed Stratus OCT ONH imaging a few minutes later consisting of six radial scans on the ONH. In both healthy and glaucoma subjects the authors found that the Cirrus HD-OCT provided higher CDR measurements than Stratus. Differences were also seen with measurements of the disc and rim areas.

Reference

Comparison of optic nerve head parameter measurements obtained by time-domain and spectral-domain optical coherence tomography.
Savini G, Barboni P, Carbonelli M, et al.
JOURNAL OF GLAUCOMA
2013;22(5):384-9.

Journal of Pediatric Ophthalmology and Strabismus

Effects of clonidine vs. placebo
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

The purpose of this study was to measure postoperative agitation using a standardised scale and evaluate whether it is reduced if given clonidine prior to strabismus surgery as compared to placebo. The scales included the Pediatric Anesthesia Emergence Delirium (PAED) and Watcha and given, by blinded assessment, at 15 minute intervals from the time the child returned to the post-anaesthesia care unit after surgery until discharge from the unit. Follow-up was by telephone contact with parents to assess patient satisfaction and subjective degree of postoperative agitation. This prospective double blind trial included 50 patients aged eight months to 13 years. Results showed no significant difference in groups at baseline and no significant difference in PAED or Watcha outcomes at time zero or discharge or for any difference in preoperative questionnaires. The placebo group had higher Watcha scores showing more agitated behaviour but this was not significant. A statistically significant difference was seen with postoperative questionnaires. Parents of children on clonidine reports them as being sleepy at discharge and were more likely to sleep more. Older children had less incidence of postoperative agitation. The authors concluded that clonidine reduced postoperative agitation but increased drowsiness.

Reference

Clonidine premedication versus placebo: effects on postoperative agitation and recovery time in children undergoing strabismus surgery.
Heinmiller LJ, Nelson LB, Goldberg MB, Thode AR.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:150-4.

Journal of Pediatric Ophthalmology and Strabismus

Strabismus in craniosynostosis
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

This review article provides a comprehensive overview of the cause of craniosynostosis, types of syndromes and with a specific purpose of discussing strabismus related to craniosynostosis. The authors report their review in the following sections: prevalence and types of strabismus and ocular motility problems, mechanism of how strabismus occurs, the role of imaging of extraocular muscles and orbits, the surgical treatment to correct strabismus and ocular motility disorders, timing of strabismus surgery and craniofacial surgery. The review concludes with the authors’ own experiences and recommendations.

Reference

Strabismus in craniosynostosis.
Rosenberg JB, Oren TM, Medow NB.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2013;50:140-8.

Journal of Refractive Surgery

Errors in refractive surgery
Reviewed by: Dr Amit Patel
Dec/Jan 2013 (Vol 20 No 4)
 

A retrospective case series looking at sources of errors in patients undergoing laser refractive surgery. Twenty-two cases of error were identified in 18 patients; 15 were unilateral, three bilateral and two errors occurred in the same eye (on attempting correction of first error). Sources of error included cylinder conversion (11 eyes), data entry (seven eyes) and patient identification (four eyes). Patients that were not candidates for further surgery and those with data entry errors had the worst outcome. The paper discusses similar reports in the literature and although it makes interesting reading, the sample is small and biased (most cases reported here were operated on elsewhere). The authors’ own estimate is an incidence of 280 to 400 cases of error per year, suggesting that most cases are not reported in the literature.

Reference

Sources of medical error in refractive surgery.
Moshirfar M, Simpson RG, Dave SB, et al.
JOURNAL OF REFRACTIVE SURGERY
2013;29(5):303-10.

Journal of Refractive Surgery

Piggyback toric IOLs in complex cases
Reviewed by: Dr Amit Patel
Dec/Jan 2013 (Vol 20 No 4)
 

This study evaluates the outcome of toric sulcus fixated lenses (MS 614/714 TPB (Human Optics, Germany) in 21 eyes with high astigmatism. The cases included previous penetrating keratoplasty (n=15), post cataract surgery astigmatism (n=3), rotation of in-the-bag toric IOL (n=1), undetected keratoconus following cataract surgery (n=1) and congenital astigmatism (n=1). A 71% reduction in astigmatism was achieved and 13 eyes (65%) achieved a spherical equivalent within 1.0 dioptres. Five eyes required a secondary axis adjustment. Three eyes developed postoperative corneal oedema, of which one required a transplant. A further two eyes developed graft failure necessitating explantation of the IOL and a re-graft. Other complications included transient intraocular pressure rise (n=2) and pigment dispersion (n=2). The authors did not evaluate binocular function following treatment. The failure to achieve a higher proportion nearer to the target refraction is explained by the lack of dioptric range, surgically induced astigmatism and case complexity.

Reference

Implantation of three-piece silicone toric additive IOLs in challenging clinical cases with high astigmatism.
Thomas BC, Auffarth GU, Reiter J, et al.
JOURNAL OF REFRACTIVE SURGERY
2013;29(3):187-93.

Ocular Immunology and Inflammation

Culture positivity of needles for IVT injections
Reviewed by: Dr Saruban Pasu
Dec/Jan 2013 (Vol 20 No 4)
 

Given the worldwide use of intravitreal (IVT) injections, the authors of this paper set out to evaluate the rate of culture positivity of the needles used in routine IVT injections and compare this positivity between 27-gauge and 30-gauge needle tips. With an endophthalmitis risk of 0.02% the source of the organisms is assumed to be ocular surface and especially lid margin, meibomian orifices, and also oral and nasal bacterial flora. Currently no data exists comparing the contamination rates between 27 and 30-gauge needles used in IVT injection. Participants for the study were enrolled from consecutive patients who were scheduled to undergo IVT injections of either ranibizumab, bevacizumab or triamcinolone acetonide regardless of the indication. The injections were performed in the operating room by the same surgeon following the same protocol each time. Immediately after the injection, a sterile forceps was used to remove the needle from the syringe and drop it into the brain-heart infusion broth. A control group was also designed in order to eliminate field contamination. One hundred and twenty-six IVT injections procedures were performed, 62 were performed using 27-gauge needles, and 64 injections were performed using 30-gauge needles. Twenty-seven (21%) needles were culture positive. No cases of endophthalmitis were reported. The number of culture-positive 27-gauge needles was eight, representing 29.7% of all positive used needles and 13% of all 27-gauge injections. The number of culture-positive 30-gauge needles was 19, representing 70.3% of all positive used needles and 29% of all 30-gauge injections. Culture-positivity was different between 27- and 30-gauge groups (p=0.022). However, after Bonferroni's correction was applied for multiple comparisons, this difference was non-significant (p>0.05). Of the control needles, 3.9% were culture positive. The used needle and its matching control needle were culture-positive with the same organism in two samples, which proves field contamination resulted in the positive culture for the paired needles. Coagulase negative Staphylococcus, found in 17 (53%) needles, was the most frequent organism. The results suggest that the contamination rate between 27- and 30-gauge needles is similar during IVT injection.

Reference

Bacterial contamination of needles used for intravitreal injections: comparison between 27-gauge and 30-gauge needles.
Ail Tufan H, Vural A, Gencer B, et al.
OCULAR IMMUNOLOGY AND INFLAMMATION
2013;21(5):366-70.

Ophthalmic Genetics

Molecular genetics of achromatopsia
Reviewed by: Dr Nana Theodorou
Dec/Jan 2013 (Vol 20 No 4)
 

Achromatopsia is a rare autosomal recessive disorder of the cone photoreceptors. Typical characteristics of affected patients include the inability to distinguish colours, impaired visual acuity, photophobia and nystagmus. The condition is said to be more frequent in the Pingelapese population of the Pacific islands. This study included 16 patients from Newfoundland, Canada who were sequenced for mutations in four known achromatopsia genes (CNGA3, CNGB3, GNAT2, and PDE6C). Twelve of the patients were found to be either homozygotes or compound heterozygotes for known achromatopsia alleles, two in CNGB3 (p.T383fsX and p.T296YfsX9) and three in CNGA3 (p.R283Q, p.R427C and p.L527R). Haplotype reconstruction showed that recurrent mutations p.T383fsX and p.L527R were due to a founder effect. Aggregate data from exome sequencing, segregation analysis and archived medical records supported a diagnosis of Jalili syndrome in four affected siblings from one of the participating families. According to the authors this was the first family identified with Jalili Syndrome in North America.

Reference

Molecular genetics of achromatopsia in Newfoundland reveal genetic heterogeneity, founder effects and the first cases of Jalili syndrome in north America.
Doucette L, Green J, Black C, et al.
OPHTHALMIC GENETICS
2013;34(3):119-29.

Ophthalmic Plastic and Reconstructive Surgery

Reliability of Fluorescein Dye Disappearance Test (FDDT)
Reviewed by: Mr Vinod Gauba
Dec/Jan 2013 (Vol 20 No 4)
 

The authors look at the role of the FDDT in the evaluation of adults with primary acquired nasolacrimal duct obstruction (PANDO) and its correlation with the age and severity of epiphora. They report the results of a prospective cross-sectional comparative study looking at FDDT at two, five and 10 minutes in 58 eyes of 58 patients with PANDO and, as a control, they also looked at the same number of cases without epiphora. Patients with functional, incomplete obstruction or upper lacrimal system obstruction were excluded. They found that the two minute FDDT showed a sensitivity of 82.8%, specificity of 91.4%, positive predictive value of 90.6%, and negative predictive value of 84.1%. The five minute FDDT showed a lower sensitivity and negative predictive value but an increased specificity and positive predictive value. They found no correlation between FDDT and severity of epiphora or age. The results support the continued use of the FDDT as a simple, reliable and specific test in the evaluation of PANDO in adults.

Reference

Reliability of Fluorescein Dye Disappearance Test in assessment of adults with nasolacrimal duct obstruction.
Kashkouli MB, Mirzajani H, Jamshidian-Tehrani M, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2013;29(3):167-9.

Ophthalmic Research

Correlation between peak intraocular pressure following water drinking test and pulsed methylprednisolone therapy
Reviewed by: Mr Bheemanagouda Patil
Dec/Jan 2013 (Vol 20 No 4)
 

Steroids have long been known to cause increased intraocular pressures (IOP) in susceptible patients. Intravenous methylprednisolone is used to treat many rheumatological conditions and one of the risks is raised intraocular pressure. It would be useful to find patients at risk. In this prospective study of 20 patients, the aim was to find out if there is any correlation between the peak intraocular pressure and the change in intraocular pressure following water drinking test and intravenous methylprednisolone pulse therapy. Water drinking test was done prior to starting steroid therapy and the peak IOP and change in IOP was noted. Similar parameters were noted when patients had their pulsed steroid therapy. A significant correlation was observed between the water drinking test and intravenous methylprednisolone therapy IOP changes (r=0.5, p=0.007) and peak IOPs (r=0.6, p=0.001). Thus the authors conclude that water drinking test could be an inexpensive tool in determining the IOP peak and change following intravenous methylprednisolone pulse therapy.

Reference

Correlation between peak intraocular pressure of the water drinking test and peak intraocular pressure induced by intravenous methylprednisolone pulse therapy.
Kowsarnia S, Aflaky E, Banifatemi M, Razeghinejad MR.
OPHTHALMIC RESEARCH
2013;50(4):187-91.

Ophthalmic Research

Erythropoietin in healing corneal epithelial defects in rabbits
Reviewed by: Mr Bheemanagouda Patil
Dec/Jan 2013 (Vol 20 No 4)
 

Corneal epithelial defects heal slowly in patients with diabetes, limbal stem cell deficiency and severe chemical burns. Erythropoietin is a glycoprotein hormone that promotes red blood cell proliferation and inhibits apoptosis of erythroid progenitors as well as nonhematopoietic cells. In this study, 15 New Zealand albino rabbits were divided into three groups following creation of unilateral, uniform corneal abrasion. First group received local treatment with erythropoietin-containing cellulose-based gel four times daily. The second group received treatment with no erythropoietin and the third group did not receive any treatment. The healing process was monitored daily with cobalt-blue-filtered slit-lamp photography until the cornea was fully epithelised. The corneas were then removed for histology. The time to epithelise was not statistically different in the three groups. Thus the study concluded that erythropoietin has no beneficial effect on the rate of corneal abrasion healing in rabbit eyes.

Reference

Effect of Erythropoietin on healing of corneal epithelial defects in rabbits.
Livny E, Livnat T, Yakimov M, et al.
OPHTHALMIC RESEARCH
2013;50(2):129-33.

Ophthalmology

Long-term results of cross-linking treatment for keratoconus
Reviewed by: Mr Brian Ang
Dec/Jan 2013 (Vol 20 No 5)
 

The authors report on the long-term outcomes in a prospective case series of patients with keratoconus undergoing corneal collagen cross-linking (CXL) treatment. Thirty-two patients (40 eyes; mean age 22.5+/-5.5 years) with Grade I, II and III progressive keratoconus were recruited for this study. For the CXL treatment, the corneal epithelium was first removed before riboflavin 0.1% was instilled every three minutes for 30 minutes. The eye was then checked at the slit-lamp to confirm penetration of the riboflavin. Ultraviolet irradiation was done with the device (wavelength 370nm, width 9mm) placed at a perpendicular distance of 5cm from the eye for a total of 30 minutes, during which riboflavin instillation was continued at three minute intervals. After irradiation, the eye was irrigated with sterile balanced salt solution and a soft bandage contact lens was placed. Post-procedure medications included chloramphenicol 0.5%, betamethasone 0.1% and preservative artificial tears. Patients were examined at one month, three months, six months, one year, two years, four years and five years after CXL treatment. Over the five year study period, Pentacam scan results showed the mean maximum keratometry and mean keratometry to decrease slightly (non-significant). CCT increased significantly up to 12 months after treatment, but no change was seen after that. Mean anterior elevation and mean posterior elevation increased at six months and one year, but decreased thereafter until five years. No significant long-term adverse effect was noted. The results from this study suggest that CXL is a safe way of stopping keratoconus progression over the long-term, at least in this cohort of patients. The long-term results from the larger trials are keenly awaited.

Reference

Corneal collagen cross-linking with riboflavin and Ultraviolet A irradiation for kerataoconus.
Hashemi H, Seyedian MA, Miraftab M, et al.
OPHTHALMOLOGY
2013;120:1515-20.

Ophthalmology

Moxifloxacin 0.5% for bacterial keratitis
Reviewed by: Mr Brian Ang
Dec/Jan 2013 (Vol 20 No 5)
 

The authors report on the results of a randomised controlled trial comparing commercially available non-preserved moxifloxacin 0.5% vs. a combination of fortified cefazolin 5% and tobramycin 1.3% in the treatment of moderate bacterial keratitis without perforation. Corneal scrapings were collected from the base and edges of the infiltrate; these were examined with Gram stain and also plated on culture plates of blood agar, chocolate agar, Saboraud’s agar and thioglycolate broth. After randomisation, study participants used the antibiotics hourly day and night for the first 72 hours. Thereafter, the frequency was reduced to two hourly for the next seven days, following which they were tapered according to clinical improvement. No steroids were used. Patients were examined at baseline, days one, four, seven, 14, and 21, as well as at three months. Anterior segment photographs were taken at each visit. Healing was deemed to have occurred once the epithelial defect had closed and the stromal infiltrate had resolved at or before three months. One hundred and ten patients treated with tobramycin and cefazolin and 108 patients treated with moxifloxacin completed the three month follow-up period. The commonest bacteria isolated were coagulase-negative Staphylococcus, Staphylococcus aureus and Pseudomonas aeruginosa – the proportion of these bacteria isolated was similar in both treatment groups. Baseline characteristics, including risk factors such as trauma, contact lens use and lagophthalmos, were not statistically significantly different between both groups. In terms of outcome, there were no statistically significant differences between the proportion of patients that achieved healing and the proportion that got worse. The mean time to re-epithelialisation was also not significantly different between groups. Additionally, there were no serious adverse events from use of either therapy. This is a well-conducted trial that demonstrates that moxifloxacin 0.5% is as effective as combined fortified cefazolin and tobramycin in the treatment of moderate bacterial keratitis. With moxifloxacin 0.5% now being commercially available and non-preserved, it may now become a more popular treatment option for bacterial keratitis, although the threat of resistance developing does remain a concern.

Reference

Evaluation of moxifloxacin 0.5% in treatment of nonperforated bacterial corneal ulcers. A randomized controlled trial.
Sharma N, Goel M, Bansal S, et al.
OPHTHALMOLOGY
2013;120:1173-8.

Ophthalmology

Rebamipide 2% for dry eye
Reviewed by: Mr Brian Ang
Dec/Jan 2013 (Vol 20 No 4)
 

Rebamipide is a quinolinone derivative that has been found to increase mucin production and the number of conjunctival goblet cells. A previous phase two study has shown rebamipide 2% to be better than placebo in improving the ocular surface and reducing symptoms of dryness. In this paper, the authors report on the results of a randomised, multi-centre phase three trial comparing rebamipide 2% to sodium hyaluronate 0.1% for the treatment of dry eye syndrome. In this trial, participants with dry eye were randomised to receive a four week course of either rebamipide 2% qid or sodium hyaluronate 0.1% six times daily. Patients were examined before the commencement of the trial, at two weeks, four weeks, and finally two weeks after the end of treatment. The following outcome measures were evaluated: fluorescein corneal staining score, lissamine green conjunctival staining score, tear film breakup time, Schirmer test score, subjective symptoms (foreign body sensation, dryness, photophobia, pain, and blurred vision) scored from zero (asymptomatic) to four (very severe symptoms), and overall treatment impression scored from one (markedly improved) to seven (markedly worsened). A total of 188 patients were recruited, with 93 patients receiving rebamipide 2% and 95 receiving sodium hyaluronate 0.1%. At four weeks, rebamipide 2% had greater improvement in the fluorescein corneal staining score, lissamine green conjunctival staining score, and symptoms of foreign body sensation and eye pain. There was no significant difference in the Schirmer test score or tear film break-up time. However, more patients also commented that their symptoms had markedly improved using rebamipide 0.2% (64.5%) compared to sodium hyaluronate 0.1% (34.7%). There were no serious adverse events with using rebamipide 2%; the commonest side-effect was a bitter taste occurring in nine patients (9.7%). The efficacy and safety of rebamipide 2% as demonstrated in this trial suggests that it may become a useful additional treatment option for dry eye syndrome. What is required now is a trial evaluating the longer term efficacy and side-effects of rebamipide 2% treatment.

Reference

A randomized, multicenter Phase 3 study comparing 2% rebamipide (OPC-12759) with 0.1% sodium hyaluronate in the treatment of dry eye.
Kinoshita S, Oshiden K, Awamura S, et al.
OPHTHALMOLOGY
2013;120:1158-65.

Ophthalmology

Swept-source OCT for measuring peripheral anterior synechiae
Reviewed by: Mr Brian Ang
Dec/Jan 2013 (Vol 20 No 4)
 

The authors report on a cross-sectional study looking at swept-source optical coherence tomography (SS-OCT) for measuring the area and degree of peripheral anterior synechiae (PAS) in patients with angle closure glaucoma. The SS-OCT is commercially available, has a laser wavelength of 1,310nm, scan speed of 30,000 A-scans per second, and axial resolution of less than 10 microns. In this study, selection of the ‘angle analysis’ protocol with 128 radial B-scans, allowed 360-imaging of the entire angle in 2.4 seconds. For each radial scan, the scleral spur and anterior irido-angle adhesion (iris end point) was manually detected; following which the built-in software would measure the extent of PAS in each meridian. These could then be reconstructed in 3D. Scans were performed for 23 eyes of 20 patients with chronic angle closure glaucoma with PAS as confirmed on indentation gonioscopy. The mean area of PAS was 20.8(±16.9)mm2, while the mean degree of PAS involvement was 186.5(±79.9) degrees. There was good agreement between SS-OCT and gonioscopy photographs, with a kappa value of 0.79. Interobserver variability was low with a high interobserver intraclass correlation coefficient of 0.99. Additionally, it was possible to distinguish between appositional and synechial angle closure – the angle would open in the light in appositional angle closure but would remain closed in synechial angle closure. SS-OCT is an exciting imaging tool for assessing the drainage angle because it is able to provide non-contact, fast, reproducible and objective measurements of PAS. This allows PAS progression and extent to be assessed more meaningfully, especially in the context of intraocular pressure control and glaucoma progression.

Reference

Anterior chamber angle imaging with swept-source optical coherence tomography: measuring peripheral anterior synechiae in glaucoma.
Lai I, Mak H, Lai G, et al.
OPHTHALMOLOGY
2013;120:1144-9.

Ophthalmology

The long-term effects of AREDS on AMD progression
Reviewed by: Mr Brian Ang
Dec/Jan 2013 (Vol 20 No 5)
 

The Age-Related Eye Disease Study (AREDS) was an 11-centre, double-masked, clinical trial that in 2001 found a high-dose of antioxidant vitamins plus zinc was effective in protecting against progression of age-related macular degeneration (AMD) in patients with moderate to high risk of progression to advanced AMD. The outcomes from the surviving 4,203 trial participants (over an average follow-up period of 6.3 years) showed that combined treatment with high dose antioxidants (vitamin C 500 mg, vitamin E 400 IU and beta-carotene 15mg) and zinc reduced the risk of progression to advanced AMD in comparison to placebo. Of the participants, 3,549 subsequently agreed to additional follow-up to 2005, thus giving a total of 10 years of follow-up. This follow-up study found that the beneficial effects of antioxidants plus zinc persisted for those originally randomised to them. Additionally, these patients also had a reduced risk of moderate and severe vision loss. No serious long-term adverse effects were found. However, it was interesting that patients randomised to zinc had a significant reduction in mortality, but the reasons for this remains unclear.  The results from this study reaffirm the long-term beneficial effects of the AREDS formulation in patients with intermediate AMD or advanced AMD in one eye.

Reference

Long-term effects of Vitamins C and E, ß-Carotene, and zinc on age-related macular degeneration. AREDS Report No. 35.
Chew EY, Clemons TE, Agron E, et al.
OPHTHALMOLOGY
2013;120:1604-11.

Orbit

A simple technique for managing eyelid retraction in a patient with an exposed Boston type 2 keratoprosthesis (Kpro)
Reviewed by: Mr Konal Saha
Dec/Jan 2013 (Vol 20 No 5)
 

The article describes a patient with mucous membrane pemphigoid and a Boston type 2 Kpro. In the early postoperative period (one week) inferior skin retraction was noted with exposure of the Kpro and carrier cornea. The exposure was managed by fashioning a disc of porous polyethylene to surround the Kpro optic. This disc was positioned under the surrounding eyelid tissue which was advanced around the optic using a purse string suture. The intervention was successful with no further treatment of the exposure required at two years follow-up. The technique is appealing due to the immediate visual recovery and lack of any donor site morbidity.

Reference

Use of a porous polyethylene lid spacer for management of eyelid retraction in patients with Boston type 2 keratoprosthesis.
Sivaraman KR, Aakula VK, Sajja K, et al.
ORBIT
2013:32(4);247-9.

Retina

Pars plana vitrectomy for vitreomacular traction syndrome
Reviewed by: Nikolaos D. Georgakarakos 
Dec/Jan 2013 (Vol 20 No 4)
 

This paper presents a meta-analysis and systematic review of the safety and efficacy of vitrectomy for vitreomacular traction (VMT), based on 21 eligible articles from 460 identified. A strength of this study is that it provided pooled analysis across a range of studies using standardised data collection and predefined outcome measures. Regarding efficacy it was found that approximately one third of eyes gained two snellen lines (0.25 logMAR lines gain on average). The authors emphasised that these visual gains might be less than anticipated. Patients who complained preop with distortion may find surgery beneficial despite unchanged visual acuity, if distortion is reduced postop. Safety seems to be acceptable. The commonest intraop complication is spontaneously resolving intraretinal haemorrhage. Postoperative retinal detachment occurred in 4.6% which is higher than expected and may be explained by the fact that in VMT the vitreous is attached and posterior vitreous detachment (PVD) intraop induction increases the iatrogenic risk of retinal breaks. Two thirds of phakic patients required cataract surgery after VMT surgery as expected (known risk of 69% to require cataract surgery in two years after pars plana vitrectomy (PPV).

Reference

Pars plana vitrectomy for vitreomacular traction syndrome.
Jackson T, Nicod E, Angelis A, et al.
RETINA
2013;33:2012-7.

Strabismus

BT for Duane’s retraction syndrome esotropia
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

The aim of the study was to evaluate the correction of esotropia and face turn due to Duane’s retraction syndrome (DRS) type I. The mean age was 21 months (12-36 months). The mean dose of botulinum toxin (BT) was 5.6±1.8IU (2.75 to 7.5) diluted in 0/9% saline solution. Mean follow-up was 74±71 months (18 months to seven years). Six patients had one injection and two patients had two injections. The mean preoperative esotropia was 32±10PD reducing to 9±12PD at final assessment. At final assessment, four patients had a deviation of 0-4PD, one had a 3PD exotropia with 5PD hypertropia, and three patients had a mean esotropia of 25PD requiring surgery. Complete limitation of abduction was noted in five patients. Face turns ranged from 15 to 45 degrees but improved in all cases. Ptosis occurred in three cases and one patient developed a vertical deviation post BT. The authors conclude that their patients achieved a good result and propose that BT should be considered as a treatment option in young patients with DRS in which surgery needs to be delayed or avoided.

Reference

Botulinum toxin in patients up to three years of age who have esotropic Duane’s retraction syndrome.
Maya JF, Gomez de Liana R, Catalan MRG, Reward O.
STRABISMUS
2013;21:4-7.

Strabismus

BT for retinal detachment strabismus
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

The authors report the use of botulinum toxin (BT) as a treatment option in 140 patients with strabismus relating to retinal detachment surgery. The BT dose was 2.5 units of Dysport. Mean follow-up was 27 months (3-203) with a mean age of 47.8 (14-82 years). Fourteen patients had asymptomatic strabismus prior to the retinal detachment surgery. The main presenting symptom was diplopia in 61% and appearance of strabismus in 39%. Post BT, 24% were symptom free, 5% continued with prisms, 18.6% required further BT, 18.5% required surgery, 9% opted for occlusion, 6% refused further treatment and 18.6% failed to attend further appointments. Four patients developed ptosis or vertical deviation following BT. The authors conclude that BT is a safe and acceptable alternative.

Reference

The use of botulinum toxin to treat strabismus following retinal detachment surgery.
Gardner R, Dawson EL, Adams GG, Lee JR.
STRABISMUS
2013;21:8-12.

Strabismus

Fibrosis treated with amniotic membrane
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

In this paper, the authors describe the surgical management of complex strabismus using amniotic membrane grafts in six patients with complex, repeat previous strabismus surgery and two patients with periocular surgery. Frozen amniotic membrane allograft was used. The study had a mean follow-up of 15 months (9-24), mean age of 34±21.5 years and mean number of previous surgeries of 3.2±1.5. Indication for surgery was a large hypotropia with inferior conjunctival fibrosis in seven cases and one patient with a large consecutive horizontal deviation. The mean preoperative vertical angle was 32.1±13PD reducing postoperatively to 19.75±11.4PD. Six patients had objective improvement with an increase in their binocular field of vision. There were no complications. Two patients needed follow-up botulinum toxin or prisms. The authors conclude that this treatment is beneficial and can be considered in early six stages of surgical planning. They discuss its dual role acting as a platform for healthy conjunctiva to grow over the previous fibrosis and secondary as a barrier between the conjunctiva and tenons / sclera.

Reference

The use of amniotic membrane for the management of fibrosis in complex strabismus surgery.
Frangouli O, Adams GG.
STRABISMUS
2013;21:13-22.

Strabismus

Functional success of strabismus surgery
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

For this study the authors reviewed patients with bilaterally poor vision undergoing surgery for ocular realignment. Their vision was sufficiently low that patients could not assess their appearance. The purpose of the study was to document patient satisfaction with strabismus surgery in this cohort of 17 patients. Their mean age was 36 years (19-44); 13 exotropia patients had a mean angle of 52PD (20-90) and four esotropic patients had a mean angle of 54PD (30-70). No patient had diplopia. The patients were aware of perceptions of others regarding their ocular alignment and this influenced their feelings about themselves and their quality of life. All were happy with the postoperative outcome with improvement in their self-esteem and overall confidence.

Reference

Beneficial effect of treatment for strabismus in patients with bilaterally poor vision who cannot see their strabismus.
Dawson ELM, Leung H, Webster A, Lee JP.
STRABISMUS
2013;21:33-6.

Strabismus

Literature review of OKN
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

The authors conducted a critical review of the optokinetic nystagmus (OKN) literature to consider OKN and in particular, vertical OKN. The review provides an overview of OKN to aid understanding of the eye movements. It provides a review of the literature relating to neurological control of POKN showing the complexity of this and inter relations between cortical and sub cortical pathways. It considers horizontal OKN, vertical OKN and the effects of target change in OKN gain. There is strong evidence supporting symmetry of horizontal OKN in normal adults. There is little agreement on vertical OPKN asymmetry. Thus the authors suggest that the finding of asymmetrical vertical OKN should prompt investigation of potential neurological pathology.

Reference

OKN asymmetry in human subjects: a literature review.
Knapp CM, Proudlock FA, Gottlob I.
STRABISMUS
2013;21:37-49.

Strabismus

Superior oblique posterior tenotomy for orbital fracture strabismus
Reviewed by: Dr Fiona Rowe
Dec/Jan 2013 (Vol 20 No 4)
 

The use of superior oblique posterior tenotomy (SOPT) is reported as a primary procedure in five patients with orbital blowout fractures. The mean follow-up was 15.2 months (6-20). Two patients required further surgery because of a larger vertical deviation. SOPT matches the contralateral failure of depression due to inferior rectus weakness without causing significant changes in the primary deviation. The authors propose the benefit of surgery in the contralateral eye away from scarring of the orbital fracture and surgical repair. They propose this as a useful procedure for small vertical deviations where symptoms are mainly in down gaze.

Reference

Contralateral superior oblique posterior tenotomy (SOPT): a primary treatment for diplopia in down gaze following blowout orbital fractures.
Garrick A, Durnian J, Hewitt G, Marsh I.
STRABISMUS
2013;21:29-32.

Strabismus

Thyroid recession drift
Reviewed by: Dr Fiona Rowe
Eye News
 

The authors investigated patients with thyroid ophthalmopathy (TO) who underwent unilateral inferior rectus recession for hypotropia with or without adjustable sutures to determine extent of postoperative surgical alignment. Group A comprised 13 TO patients with inferior rectus recession with adjustable sutures. Group B comprised 14 TO patients with inferior rectus recession without adjustable sutures. Group C comprised 19 patients without TO undergoing recession with adjustable sutures. Group A responded differently to group C. Patients with TO had larger dose responses per mm of recession compared to controls with or without adjustable. TO patients had a drift back towards over correction. There was no significant difference between groups A and B.

Reference

Postoperative drift in patients with thyroid ophthalmopathy undergoing unilateral inferior rectus muscle recession.
Peragallo JH, Velez FG, Demer JL, Pineles SL.
STRABISMUS
2013;21:23-8.

Acta Ophthalmologica

Visual field progression in glaucoma
Reviewed by: Dr Nana Theodorou
Oct/Nov 2013 (Vol 20 No 3)
 

This study evaluated perimetric rates of progression in glaucoma patients attending an eye clinic in Sweden. A retrospective study was undertaken which included 583 eligible patients with a mean age of 71.4 years. Two sub-groups were identified: 62% with primary open angle glaucoma and 38% with pseudoexfoliation glaucoma. The parameters collected were demographics, intraocular pressure, treatment and visual field data. Visual field progression rates were calculated as slopes of mean deviation over time. The results indicated that progression rates varied considerably amongst patients with a mean of -0.80dB/year and 5.6% of the patients progressed at rates worse than -2.5 dB/year. Mean intraocular pressure (IOP) values decreased from 20.1 to 18.1mmHg. Higher age, mean IOP and more extensive treatment were all associated with a more rapid progression.

Reference

Rates of visual field progression in clinical glaucoma care.
Heijl A, Buchholz P, Norrgren G, et al.
ACTA OPHTHALMOLOGICA
2013;91:406-12.

American Journal of Ophthalmology

Substance misuse in pregnancy and visual morbidity in children
Reviewed by: Mr K C Madhusudhana MD FRCS
Oct/Nov 2013 (Vol 20 No 3)
 

Substance misuse in pregnancy is a significant problem, with several short-term and long-term adverse effects on the foetus. It is well known that maternal substance misuse and neonatal abstinence syndrome are associated with brain and ocular abnormalities in the neonate. In this study, the authors reviewed 301 children born to mothers misusing substances during pregnancy and compared with 7,887 age-matched controls from the preschool screening cohort in the north of Scotland. Rate of referral to ophthalmology service and ophthalmic morbidities such as strabismus and nystagmus were found to be significantly higher in the study group. At baseline visit, 15.3% had strabismus (2.8% in control group) and 3.7% had nystagmus (0.004% in control group). At five year follow-up, the prevalence of strabismus was 14% (OR 5.70) and that of nystagmus was 3.3% (OR 90.34). Of these children, 42.4% lacked demonstrable binocular vision (at age five years) and 28.2% had visual acuity of 0.3 logMAR or worse in one or both eyes. Compliance with ophthalmic consultation appeared poor with an attendance rate of 61.9%. The authors conclude that the exposure to maternal substance misuse in-utero is associated with a significantly higher prevalence of strabismus and nystagmus with more long-term visual adverse effects such as poor visual acuity and lack of binocular vision. The higher prevalence of nystagmus and strabismus at age five years suggests the possibility of more severe structural impact on the developing brain than previously documented. This study highlights the need for ophthalmologic surveillance of this population to detect visual morbidities and the need to improve compliance in clinic attendance. It may be beneficial to train the health care staff in perinatal substance misuse clinics, to carry out visual screening of children.

Reference

The short- and long-term effects on the visual system of children following exposure to maternal substance misuse in pregnancy.
Cornish KS, Hrabovsky M, Neil W, Scott NW, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2013;156(1):190-4.

British Journal of Ophthalmology

Rates of childhood squint surgery in England
Reviewed by: Mr Jonathan Chan
Oct/Nov 2013 (Vol 20 No 3)
 

This is a retrospective study of the incidence of childhood strabismus surgery in England over five decades and also geographic variation. The authors analysed the hospital statistics from the Oxford record linkage study from 1963-2010, and also England 1999-2010; together with the analysis of geographic variation in England between the period of 1999 to 2010. All the patients studied were under the age of 15 years old. The annual rates of admission for squint surgery in the Oxford region show a substantial decline from 213.2 episodes per 100000 population in 1963 to 61.3 episodes in 2010. The national data from 1968 to 2010 show a similar three fold decrease in rate of admission for squint surgery from 588.8 per 100,000 population to 64.1. With regard to the vision variation in England, it shows Easington had the highest rate per 100,000 at 138.6 people per year. Kensington and Chelsea had the lowest rate at 28.2. This shows a 4.9-fold, highly significant difference between the regions of both extremes. The authors suggested that the reason for the decline of numbers of episodes during such periods could be related from a switch from surgical to non-surgical treatment, resulting in a decline of surgical cases. Another factor could be related to the introduction of a new screening programme in 2003 as a ‘gold standard’ of testing to be carried out between the ages of four and five years. The authors also suggested that the geographical variation differences may in part be related to the variation in need for surgery due to local population factors, geographic variation recognised risk factors such as a raise of maternal smoking, maternal age, family history and associated neuro-developmental problems. The other possible factor could be related to the inequality of the ophthalmic services.

Reference

Time trends over five decades, and recent geographical variation, in rates of childhood squint surgery in England.
Chou MR, Malik ANJ, Suleman M, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:746-51.

British Journal of Ophthalmology

Treatment of orbital vascular malformations
Reviewed by: Mr Jonathan Chan
Oct/Nov 2013 (Vol 20 No 3)
 

This is a view of an interventional case series of 13 patients with orbital vascular malformations. The mean age was 36 years old and six were diagnosed with venous malformations, six with cavernous haemangiomas and one with lymphangioma. All patients underwent sclerotherapy treatment with intralesional injections of pingyangmycin at Fudan University Eye Hospital from September 2009 to April 2011. All patients had clinical imaging, including computerised tomography (CT) scans before and after treatment for the measurement of the lesion volumes. The mean percentage of volume reduction was 70% range (24.5-88.3%). The average reduction of proptosis was 3.2mm (range 0-5.5mm). Both measurements were statistically significant. The average follow-up time was 13.3 months without any local or systemic side-effects found. The authors conclude that pingyangmycin is an effective treatment alternative for the orbital vascular malformations.

Reference

Treatment of orbital vascular malformations with intralesional injection of pingyangmycin.
Yue H, Quian J, Elner VM, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:739-45.

Clinical and Experimental Ophthalmology

Meta-analysis of phaco versus small incision cataract surgery
Reviewed by: Dr Kwesi Amissah-Arthur
Oct/Nov 2013 (Vol 20 No 3)
 

Despite the massive advances in modern cataract surgery, several countries cannot afford to implement phacoemulsification cataract surgery with an intraocular lens, due to its cost or requirement for more advanced surgical training. Manual small-incision cataract surgery, however, has several advantages in developing countries where its low cost, coupled with its utility in performing surgery on advanced and dense cataracts, makes it ideal. Given the number of patients worldwide with reversible blindness secondary to age-related cataracts, the question of whether there is a difference in outcome is extremely pertinent, particularly when you consider the numbers involved. This meta-analysis of six randomised controlled trials (RCTs) sought to primarily assess the proportion of people achieving good functional vision (BCVA ≥6/9) and the proportion of people with a poor visual outcome (BCVA <6/18). Uncorrected visual acuity better than 6/9 and uncorrected visual acuity worse than 6/18 were also assessed. Secondary outcomes included complications, corneal endothelial cell count and surgically induced astigmatism. The minimum follow-up time required for inclusion of RCTs was six weeks. A literature search, data extraction and quality assessment of the data were done as per general meta-analysis principles. After the literature search, 223 articles were identified, of which 14 potential controlled RCTs relevant to the comparison of phacoemulsification to manual small-incision cataract surgery were identified. Six RCTs describing a total of 1,315 eyes met all the criteria and were analysed. The trials were performed between 2005 and 2010. There were no significant differences between the techniques regarding the BCVA of 6/9 or better (P=0.69) and less than 6/18 (P=0.68), percent of endothelial corneal cell loss (P=0.45), intraoperative or postoperative complications (P=0.44 and P=0.87, respectively). However, a greater proportion of patients in the phacoemulsification group had final uncorrected visual acuity (UCVA) ≥6/9 (P=0.03), whereas a greater proportion of patients in the manual small-incision cataract surgery group had final UCVA<6/18 (P=0.03). The phacoemulsification group induced less surgically induced astigmatism (P<0.00001). There was no evidence of publication bias detected using the Begg’s and Egger’s tests. This meta-analysis shows that there is no difference between phacoemulsification and manual small-incision cataract surgery from a safety and visual rehabilitation point of view. It does, however, highlight the difference in UCVA between the two procedures with more patients in the phacoemulsification group having a VA of 6/9 or better, whereas there are more patients in the manual small-incision cataract surgery group with an UCVA of 6/18 or worse. The authors point out that given the statistically significant result with regards to surgically induced astigmatism, this might be the reason for the discrepancy in UCVAs. This work shows that manual small-incision cataract surgery is an appropriate procedure for the developing world, particularly when taken in the context of limited health care resources.

Reference

Phacoemulsification versus manual small-incision cataract surgery for age-related cataract: meta-analysis of randomized controlled trials.
Zhang J-Y, Feng Y-F, Cai J-Q.
CLINICAL & EXPERIMENTAL OPHTHALMOLOGY
2013;41:379-86.

Current Eye Research

Association between reduced total antioxidant levels and primary open angle glaucoma
Reviewed by: Dr Khadijah Basheer
Oct/Nov 2013 (Vol 20 No 3)
 

Previous studies have uncovered evidence that oxidative damage plays a key role in the pathogenesis of glaucoma. This same group of authors demonstrated that total antioxidant status (TAS) decreases in the plasma of patients with pseudoexfoliative glaucoma. This study examined the TAS levels in patients with primary open angle glaucoma (POAG) and control subjects. A total of 139 POAG patients and 148 controls were recruited. There was no statistically significant difference between the groups for age, gender or prevalence of other co-morbidities, namely diabetes and hypertension. The results showed that the mean TAS level was lower in POAG patients than in control subjects, this was statistically significant. They also correlated the TAS levels with clinical indices for POAG. There was a clear trend of decreased TAS with high intraocular pressure and patients on more than two anti-glaucoma medications. However, this was not statistically significant. There was a statistically significant correlation between TAS level and cup to disc ratio. The exact mechanism of how oxidative stress contributes to glaucoma pathogenesis is still unclear and indeed the mechanisms leading to glaucomatous optic neuropathy are also not yet clearly understood. This study provides further evidence that the pathogenesis of certain types of glaucoma may be related to oxidative stress. They have demonstrated that TAS levels are decreased in POAG patients and correlates with parameters related to POAG severity. Further studies with larger patient populations need to be conducted to verify this relationship. If they can demonstrate high specificity and sensitivity of TAS with progression of glaucoma, measuring TAS levels could be used as a marker of POAG severity and progression

Reference

Decreased total antioxidants in patients with primary open angle glaucoma.
Abu-Amero K, Kondkar A, Mousa A, et al.
CURRENT EYE RESEARCH
2013;38(9):959-64.

Experimental Eye Research

Targeting PGE2 production in orbital fibroblasts
Reviewed by: Mr Graham Wallace
Oct/Nov 2013 (Vol 20 No 3)
 

Thyroid associated ophthalmopathy (TAO) is a characteristic of Graves disease with dry eye and intraocular pressure the main symptoms. TAO is considered an autoimmune disease with both T-cells and antibodies found in orbital fat and muscles. These antibodies target antigens including the thyrotropin receptor driving hyperthyroidism, and insulin growth factor-1 receptor (IGF-1R) on orbital fibroblasts. The cyclooxygenase -2 (COX-2), an enzyme which catalyses production of prostaglandin E2 (PGE2), pathway is increased in orbital fibroblasts from patients with TAO, when the cells are treated with IL-1ß. A lack of IL-1ßR antagonist has also been linked to TAO. In this paper primary cultures of orbital fibroblasts from patients with TAO and non-TAO controls were treated with IL-1ß. Pirfenidone, a small molecule inhibitor of fibrosis via inhibition of fibroblast proliferation was tested in these cultures. The results show that IL-1ß treated significantly raised PGE2 levels in both TAO and non-TAO fibroblasts, a response that was ablated by treatment with pirfenidone. Similalry COX-2 mRNA and protein expression was inhibited by the drug as was nuclear translocation of NF-κB. The effect of perfinidone on these pathways explains in part the anti-fibrotic response reported. The potential for inhibiting the fibrotic response in TAO is strongly supported by these studies.

Reference

Pirfenidone attenuates IL-1ß –induced CXO-2 and PGE2 production in orbital fibroblasts through suppression of NF-κB activity.
Choi YH, Back KO, Kim HJ, et al.
EXPERIMENTAL EYE RESEARCH
2013;113:1-8.

Eye

Ahmed valve in a paediatric age group
Reviewed by: Mr John Brookes
Oct/Nov 2013 (Vol 20 No 3)
 

The management of glaucoma in children is challenging. Initial treatment with angle surgery can have relatively good outcomes but when angle surgery has failed, or cannot be performed, filtering surgery can have a higher risk of complications and poorer outcomes than in adults. This study from Cairo looks at the use of the Ahmed glaucoma valve and compares the results of the polypropylene model and the newer, silicone Ahmed glaucoma valve (AGV), in a prospective controlled study. Fifty eyes of 33 patients were studied in children under 10 years of age; for bilateral disease, one eye had the polypropylene valve implanted and the fellow eye had the silicone implant. At the end of the first year, 40% of patients in the polypropylene group had failed compared with 16% of patients in the silicone group. The difference in failure rates persisted in the second year and was statistically significant. Overall, multivariate analysis showed that a larger number of prior glaucoma surgeries were a predictor of treatment failure. The most common complications were hypotony, choroidal effusions and tube-related complications but there was no significant difference in the rate of complications between the two groups. The authors comment that experimental studies in rabbits have shown that polypropylene and other rigid biomaterials are associated with significantly more inflammation than silicone. This prospective study has shown clinically that silicone valves have a lower failure rate and longer survival, with less antiglaucoma drops compared with polypropylene valves.

Reference

Polypropylene vs silicone Ahmed valve with adjunctive mitomycin C in paediatric age group: a prospective controlled study.
El Sayed Y, Awadein A.
EYE
2013;27:728-34.

Investigative Ophthalmology and Visual Science

OCT versus colour photography as a screening tool – which is best?
Reviewed by: Ms Carmel Noonan
Oct/Nov 2013 (Vol 20 No 3)
 

This study compared the sensitivity of non mydriatic colour fundus photography (FP) to optical coherence tomography (OCT) for detection of retinal irregularities in asymptomatic patients. Asymptomatic patients were recruited and each had colour photography of the optic nerve and macula and OCT images of nerve and macula. Colour images were evaluated for irregularities both inside and outside the area covered by OCT. OCT image sets were evaluated for internal limiting membrane irregularities, abnormal retinal thickness, hyper/hypo-reflective features, and photoreceptor / retinal pigment epithelium (RPE) irregularities. Detection sensitivities were compared and false-negative cases were analysed. Of the 144 subjects included, 135 patients had gradable images. Detection rates with OCT were higher (96.2% infield and 85.7% in full field) than for FP (19.9% infield and 43.8% in full field) for all irregularities evaluated in the study (including epiretinal irregularities, abnormal retinal thickness, intraretinal hyperreflective / hyporeflective features, and photoreceptor / RPE irregularities). Overall, the presence of definite irregularities in asymptomatic population was 42.6% (121/284), with 39.4% (112/284) of eyes having RPE irregularities such as drusen. Overall OCT was more sensitive that FP in picking up retinal / optic nerve disease and more useful as a screening tool

Reference

The retinal disease screening study: prospective comparison of nonmydriatic fundus photography and optical coherence tomography for detection of retinal irregularities.
Ouyang Y, Heussen FM, Keane PA, et al.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
2013;54(2);1460-8.

JAMA Ophthalmology

Effect of multifocal intraocular lenses on visual fields
Reviewed by: Lorraine North
Oct/Nov 2013 (Vol 20 No 3)
 

The authors describe a cross-sectional case-control study of 16 patients with multifocal intraocular lenses (MFIOLs), 12 patients with monofocal lenses and 18 healthy subjects with phakic eyes. The aim was to evaluate the influence of exclusively diffractive MFIOLs of two types that had been used in the study population. The inclusion criteria were subjects aged 18-75 years with a post-op period of greater than three months with no other history of glaucoma, fundus abnormality, trauma or other eye disease. Humphrey visual fields were performed on all patients using first the 30-2 full-threshold 4-2-2 strategy with a III stimulus with 15 test locations. They then performed a SITA 30-2 with the same stimulus and then finally another shortened program of 15 test locations with stimulus size V. The authors found that multifocal lenses reduce the visual sensitivity in standard automated perimetry by approximately 2dB and was similar with both stimuli compared to normal subjects. The authors suggest that patients with MFIOLs who are glaucoma suspects should have an alternative perimetric baseline as the reduction could interfere with the assessment of the eye condition. The limitation of this study was the small sample size.

Reference

Influence of multifocal intraocular lenses on standard automated perimetry test results.
Aychoua N, Montolio FGJ, Jansonius NM.
JAMA OPHTHALOLOGY
2013;131(4):481-5.

Journal of Cataract and Refractive Surgery

Cataract surgery and reactivation of herpetic disease
Reviewed by: Ms Anju Kadyan
Oct /Nov 2013 (Vol 20 No 3)
 

This paper reports a survey trying to garner expert opinion on a clinical scenario (patients with history of herpetic eye disease undergoing cataract surgery) where higher levels of evidence are difficult to obtain. UK consultants with specialist interest in cornea (n=106) were surveyed with a 70% response rate. The current practice of this sub-group was based on principles of cataract surgery in presence of any ocular inflammation. They preferred to operate when the eye was quiescent for three to six months and used regular topical steroids postoperative regime but with more frequent and longer period of reviews than routine cataract surgery. The Herpetic Eye Disease (HED) study has shown the benefit of reducing recurrence of stromal keratitis with acyclovir 400mg BD. Similar oral antiviral prophylaxis has been commonly used for corneal surgery like penetrating keratoplasty, excimer laser and LASIK. This was the most common regime used for prophylaxis started seven days pre-operatively and continued to cover the duration of topical steroid use. The dose of acyclovir was usually not increased for cataract surgery if the patient was already on prophylactic treatment. The authors suggest use of topical nonsteroidal anti-inflammatory drugs (NSAID) (safer than topical steroids) and other antiviral drugs like valcyclovir or famcyclovir which have better bio-availability and can be taken less often than acyclovir, although these were preferred by only a small number of respondents.

Reference

Management of patients with herpes simplex virus disease having cataract surgery in the United Kingdom.
Sykakis E, Karim R, Parmar DN.
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2013;39:1254-9.

Journal of Glaucoma

PDCT vs. GAT
Reviewed by: Lorraine North
Oct/Nov 2013 (Vol 20 No 3)
 

The authors describe a prospective single centre study comparing the utility of Pascal dynamic contour tonometry (PDCT) with Goldmann applanation tonometry (GAT) in routine clinical practice. Ten clinicians of different grades recruited 97 patients between them and measured intraocular pressure using both methods in a randomised order. They each recorded the time taken with each instrument, number of measurements to obtain a satisfactory reading and the quality of the reading. The patient was also asked to describe their experience with the instruments. The results showed that satisfactory results were obtained with PDCT in 181 of the 194 eyes. However, the clinicians found it to be more time-consuming and difficult to use compared to GAT and in some cases repeated PDCT was required. With regard to patient experience, although some preferred GAT to PDC, most patients expressed no preference.

Reference

Comparison of the utility of pascal dynamic contour tonometry with Goldmann applanation tonometry in routine clinical practice.
Anderson MF, Agius-Fernandez A, Kaye SB.
JOURNAL OF GLAUCOMA
2013;22(5):422-6

Journal of Refractive Surgery

Near vision after monofocal IOL implantation
Reviewed by: Dr Amit Patel
Oct/Nov 2013 (Vol 20 No 3)
 

A retrospective study in which the authors aim to identify factors associated with good near vision after monofocal implantation in 84 eyes (targeted for emmetropia). All eyes had uneventful surgery and postoperative refractive error was within ±0.5 dioptres (D) spherical equivalent and astigmatism within ±0.75D. Factors studied included age, sex, axial intraocular lense (IOL) movement, axial length, pupil size, corneal multifocality, degree and type of astigmatism, total and higher-order aberrations. Near vision was classified as good (≥J4) in 34 eyes or poor (<J4) in 50 eyes. Of the above factors small pupil size (p=0.04) and short axial length (p=0.027) were associated with good near vision. The authors explain this by the increased depth of focus and greater accommodation in shorter eyes. The cut off values for pupil size and axial length were 2.6mm and 23mm respectively. The authors excluded high postoperative astigmatism and thus may not effectively conclude that astigmatism does not play a role in near vision. Furthermore, they acknowledge that the amplitude of accommodation was not measured directly and that an older age group (average age 65.7 years) may exclude any ‘pseudoaccomodative’ effect.

Reference

Factors affecting near vision after monofocal intraocular lens
implantation.
Lim DH, Han JC, Kim MH, et al.
JOURNAL OF REFRACTIVE SURGERY
2012;29(3):200-4.

Ocular Immunology and Inflammation

Therapeutic strategies for ocular toxoplasmosis
Reviewed by: Dr Saruban Pasu & Nikolaos D. Georgakarakos 
Oct/Nov 2013 (Vol 20 No 3)
 

This article describes potential new therapies to manage Toxoplasma gondii, which the authors describe as the most infectious agent for posterior uveitis throughout the world.  All of the observational clinical studies regarding antibiotic treatment regimens share the absence of a predefined measure for therapeutic success. The authors suggest the localisation and size of a lesion, the duration of symptoms, and the time to recurrence should be used as possible primary endpoints to compare treatment effects in future studies. Dihydrotriazine, a new dihyrofolate reductase inhibitor, was more effective in vitro than pyrimethamine. This new parasitocidal compound may be more effective and less toxic than existing drugs of this class. Artemisinin, a drug that has been used effectively against malaria, has shown efficacy in vitro against Toxoplasma. A recent discovery that Toxoplasma is derived from plant lineages, holds promise for targeting metabolic pathways for new drugs. Fluridone is a herbicide used in a mouse model of toxoplasmic infection where it was shown to reduce parasite burdens and cyst formation in the central nervous system (CNS) during chronic infection. Fluridone is believed to work by blocking endogenous abscisic acid, a hormone which controls intracellular calcium secretion. Toxoplasma gondii calcium-dependent protein kinases are also attractive targets as they are absent in humans. Intravitreal therapy with clindamycin with or without a combination with intravitreal steroids has also shown promise in recent years. However, studies have also reported that a stronger regression of lesion size has been demonstrated after systemic compared to local therapy. Atovaquone is the only clinically available antibiotic that may be able to extend the time to recurrence. In the immunosuppressed, prophylaxis with trimethoprim and sulfamethoxazole is capable of reducing the number of recurrences. The authors suggest a possible alternative to developing a vaccine for humans would be to vaccinate the animals responsible for human disease. The article highlights the need for more data collection with respect to treatment effects to provide patients with the best evidence when discussing management options.

Reference

Therapy for ocular toxoplasmosis – the future.
Garweg JG, Stanford MR.
OCULAR IMMUNOLOGY AND INFLAMMATION
2013;21(4):300-5.

Ophthalmic Genetics

Genetic polymorphisms associated with retinal vein occlusion
Reviewed by: Dr Nana Theodorou
Oct/Nov 2013 (Vol 20 No 3)
 

This article investigates gene polymorphisms as a risk factor for retinal vein occlusion (RVO) in a Greek unrelated case / control population. A total of 48 adult eyes affected by newly diagnosed RVO were included in this prospective study. The participants were recruited over a period of five years and were compared against a control group of 53 non affected adults from the same region. The participants were genotyped for factors V H1299R and V Leiden, ß-fibrinogen G455A, PAI-1 4G/5G, ACE I/D, HPA1, G20210A, XIII Val34Leu, MTHFR A1298C and C677T. A meta-analysis was carried out following a PubMed search up to January 2012. The results indicated that there may be an association between increased risk for RVO and ACE I/D, MTHFR C677T, PAI-1 4G/5G and factor V Leiden polymorphisms, whereas the Val34Leu variant may exert a protective effect.

Reference

Genetic polymorphisms associated with retinal vein occlusion: a Greek case control-study and meta-analysis.
Yioti GG, Panagiotou OA, Vartholomatos GA, et al.
OPHTHALMIC GENETICS
2013;34(3):130-9.

Ophthalmic Plastic and Reconstructive Surgery

Superior ophthalmic vein and extraocular muscle index in dysthyroid optic neuropathy
Reviewed by: Mr Vinod Gauba
Oct/Nov 2013 (Vol 20 No 3)
 

The authors report a retrospective review of high resolution CT scan images of 40 orbits (20 patients) that underwent prior orbital decompression surgery. Superior ophthalmic vein diameter was measured in axial and coronal planes. Extraocular muscle index was calculated by the Barrett method. The clinical diagnosis of optic neuropathy was based on international criteria. Orbits were divided into two groups based on whether they had optic neuropathy or not. The study found that superior ophthalmic vein size and extraocular muscle index were both significantly higher in optic neuropathy cases. Based on the results, the authors suggest that patients with thyroid eye disease with enlarged superior ophthalmic veins and increased extraocular muscle index are more likely to have concomitant optic neuropathy.

Reference

Superior ophthalmic vein enlargement and increased muscle index in dysthyroid optic neuropathy.
Lima B, da R, Perry J.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2013;29(3):147-9.

Ophthalmology

Treatment outcomes in malignant glaucoma
Reviewed by: Mr Brian Ang
Oct/Nov 2013 (Vol 20 No 3)
 

The authors report retrospectively on the outcomes of a case series of patients who developed malignant glaucoma. The diagnosis of malignant glaucoma was made when there was postoperative raised intraocular pressure (IOP) of 22mmHg or more associated with a shallow or flat anterior chamber despite a patent iridotomy. Successful treatment and resolution occurred when the central anterior chamber deepened and the IOP was 21mmHg or less on two successive follow-up visits at least a week apart, without the use of systemic IOP-lowering medication (topical drops were allowed). Twenty-eight eyes of 26 patients were included for analysis, of which 23 were pseudophakic and five were phakic. Eleven had trabeculectomy, 10 had cataract surgery, and seven had combined cataract and glaucoma surgery. Of note, 17 eyes (61%) already had pre-existing primary angle closure glaucoma. First line treatment was medical management with topical cycloplegics and IOP-lowering medications. Second line treatment for pseudophakic eyes was YAG laser hyaloidotomy through the peripheral iridotomy or beyond the intraocular lens haptic. Third line treatment for pseudophakic eyes (and second line for phakic eyes) was vitrectomy or trans-scleral cyclodiode laser over two to three quadrants in eyes with poor visual potential. Median follow-up duration was 192 days (interquartile range 35 to 425 days). Using the treatment algorithm as above, the malignant glaucoma resolved in 27 eyes (96%) over a median duration of 13 days (interquartile range 4 to 65 days); the final patient was lost to follow-up after three months and considered as a failure. As expected, after resolution, there was a statistically significant reduction in IOP. However, there was no significant difference in visual outcome for half of the eyes (50%; 14 eyes). This study demonstrates that malignant glaucoma can be successfully managed using the above treatment algorithm, but it can take up to two months for resolution to occur.

Reference

Treatment outcomes in malignant glaucoma.
Dave P, Senthil S, Rao HL, Garudadri CS.
OPHTHALMOLOGY
2013;120:984-90.

Ophthalmology

Visual function after one- and two-eye cataract surgery
Reviewed by: Mr Brian Ang
Oct/Nov 2013 (Vol 20 No 3)
 

The Salisbury Eye Evaluation (SEE) Project was a longitudinal population-based study measuring the clinical visual function, quality of life, and performance on multiple tasks of eligible randomly chosen community residents of Salisbury, Maryland. Performance was evaluated using the Activities of Daily Vision Scale (ADVS), which included subscales that measure near vision, far vision, glare disability, night driving and day driving. Additionally, mobility was determined from functional tests that included a four metre walk, stair ascent, stair descent and getting up from a chair. In this paper, the authors report on the 1739 study participants who originally enrolled in the SEE without prior cataract surgery in either eye. Two years from baseline, 119 (7%) patients had cataract surgery in one (90 patients) or both eyes (29 patients). The authors compared the vision, contrast sensitivity, reading speed, mobility score and ADVS of the three groups: no cataract surgery (1,620 patients), unilateral cataract surgery (119 patients) and bilateral cataract surgery (29 patients). As expected, best-corrected vision and reading speed significantly improved after unilateral and bilateral cataract surgery. Although mobility had reduced across the three groups, those who have had bilateral cataract surgery showed the least reduction. Compared to the group without cataract surgery, the bilateral cataract surgery group showed significant improvement in ADVS but the unilateral cataract surgery group demonstrated a relative decline. While the results are not surprising, they do confirm the benefit of second-eye cataract surgery. Unilateral cataract surgery increases visual function, and this study demonstrates that surgery to the second eye provides significant additional improvement in terms of mobility and daily vision activities.

Reference

Functional improvement after one- and two-eye cataract surgery in the Salisbury Eye Evaluation.
Lee BS, Munoz BE, West SK, Garudadri CS.
OPHTHALMOLOGY
2013;120:949-55.

Orbit

The effect of lateral orbital wall and rim removal during orbital decompression on lateral canthal function and appearance
Reviewed by: Mr Konal Saha
Oct/Nov 2013 (Vol 20 No 3)
 

The authors describe an orbital decompression technique involving removal of the lateral orbital wall including rim with excision of intraconal fat. The orbital rim was not replaced. The procedure was carried out on 30 orbits of 18 patients with thyroid orbitopathy and results at three and six months are presented. Mean decrease in exophthalmos was 3.0mm. Improvements in ‘quality of life’ scores were noted. Three of 18 patients complained of temporal hollowing although this was only confirmed objectively in one patient. Interestingly, no impairment of extraocular movement was noted. This problem might be anticipated due to attachments between the lateral recti and the lateral canthal tendon that are known to exist. No comment is made on loss of the protective effect of the lateral orbital rim.

Reference

Functional and esthetic outcome after bony lateral wall decompression with orbital rim removal and additional fat resection in Graves’ orbitopathy with regard to the configuration of the lateral canthal region.
Fichter N, Krentz H, Guthoff RE.
ORBIT
2013:32(4);239-46.

Retina

Microplasmin (Ocripplasmin) in paediatric vitreoretinal surgery
Reviewed by: Nikolaos D. Georgakarakos & Dr Saruban Pasu
Oct/Nov 2013 (Vol 20 No 3)
 

This article discusses the potential role of Ocriplasmin (ThromboGenics NV, Belgium) as a surgical adjunct to vitrectomy for paediatric vitreoretinal disease such as vasoproliferative diseases (retinopathy of prematurity [ROP], FEVR, incontinentia pigmenti, persistent foetal vasculature) and non vasoproliferative problems (MH, ERM peels, Stickler’s, traumatic retinal detachment [RD]). So far there are a number of trials investigating this and the paper highlights the clinical and laboratory evidence to date for the use of both autologous plasmin enzyme as an adjunct to vitrectomy and recombinant microplasmin (ocriplasmin) as monotherapy for vitreomacular traction in adults.
Ocriplasmin intravitreal injection trials in adults:
Recently phase two and three studies demonstrated that intravitreal microplasmin (Ocripolasmin) can relieve symptomatic vitreomacular adhesion avoiding the need for surgery. Ocriplasmin for IntraVitreous Injection (MIVI-I) was a phase IIa multicentre, prospective, uncontrolled, non-masked, dose-escalation study investigating the safety and preliminary efficacy of intravitreal ocriplasmin given before pars plana vitrectomy for vitreomacular traction (VMT). By day 28 no clinically significantly changes were observed. Posterior vitreous detachment (PVD) was most likely to occur with the 25um group seven-day exposure followed with the 125um group with 24hrs exposure. MIVI-IIT was a phase IIa randomised, double-masked, sham injection controlled study investigating the effect of single or repeated injections of Ocriplasmin on foveal VMA release. At day 28, fVMA was most likely to occur with 125um (44%) with a complete PVD in 24%.
MIVI-III was a phase IIb, multicentre, sham injection, controlled, double masked, dose ranging trial to evaluate the safety and efficacy of preop intravitreal injection of Ocriplasmin in patients planned to undergo vitrectomy predominately for macular hole surgery (n=54) or VMT (n= 34). The most statistically significant treatment effect was seen at 35 days post injection with 32% fVMA release versus 3% in the placebo group (p<0.01). At day 180 retinal tears without retinal detachment occurred in 3%, 7%, 15%, 12.5% in the placebo and 25-, 75-, and 125-um ocriplasmin respectively with an intraop or postop RD occurring in 3%, 0%, 0%, 6% and 0% respectively. The authors stated the study was not powered to assess safety. Two phase III multicentred, randomised, placebo controlled double masked, clinical trials have been completed. In the MIVI-TRUST (Traction released without surgical treatment) TG-MV-006 and TG-MV-007 studies, 652 patients with VMT, MH, ERM participated. There was a statistically significant greater resolution of VMA (p<0.001) and complete PVD (p<0.001) in the Ocriplasmin vs. placebo.
Ocriplasmin intravitreal injection trials in children:
Given the complexity and increased degree of difficulty in the management of paediatric vitreoretinopathy, it would seem reasonable to investigate its role in paediatric vitreoretinal surgery. Published data suggest the use of autologous plasmin enzyme (APE) in vitrectomy but given the onerous and time sensitive nature of its preparation it has been limited. Ocriplasmin could be a more readily available option. Currently a phase two single centre, randomised, placebo controlled, double masked trial is recruiting aiming to assess the safety and efficacy profile of a single dose 175um in children and infants 16 years or younger undergoing vitrectomy. It is anticipated that 24 individuals will be recruited and allocated either for a placebo or Ocriplasmin 30-60 minutes before surgery with a six month follow-up. Primary endpoints include masked assessment of vitreous liquefaction intraop, total macular PVD and retinal attachment status at follow-up.

Reference

Microplasmin (Ocriplasmin) in paediatric vitreoretinal surgery.
Wong C, Capone A.
RETINA
2013;33(2):339-48

Strabismus

Fixation disparity curve comparisons
Reviewed by: Dr Fiona Rowe
Oct/Nov 2013 (Vol 20 No 3)
 

The purpose of this study was to examine the fixation disparity curve (FDC) parameters with the modified Mallett fixation disparity unit and the Wesson FD card, and to examine the differences in the parameters between symptomatic and asymptomatic subjects. One hundred subjects were assessed: 53% female and a mean age of 22.8 years ± 2.3. Thirty symptomatic and 70 asymptomatic subjects were seen. The results show that the Wesson card has a more divergent y-intercept, a more base in x-intercept and a more negative (steeper) slope than the modified Mallett unit. Values were higher for symptomatic than asymptomatic subjects but with wide variances. Hence FD curves with these devices cannot be used to predict symptoms in patients.

Reference

Evaluation of fixation disparity curve with the modified near Mallett unit and the Wesson fixation disparity card in symptomatic and asymptomatic subjects.
Momeni-Moghaddam H, Yekta A, Ehsani M, Kundart J.
STRABISMUS
2012;20:166-74.

Strabismus

OCT in nystagmus
Reviewed by: Dr Fiona Rowe
Oct/Nov 2013 (Vol 20 No 3)
 

In this review the authors highlight some of the recent advances in optical coherence tomography (OCT) measurements of infantile nystagmus. They focus on how its use can be applied for both diagnostic and prognostic purposes. They consider structural foveal elements, diagnosis and prognosis of foveal hypoplasia (including atypical foveal hypoplasia in achromatopsia), plus clinical significance such as a role in identifying subjects suitable for gene therapy trials.

Reference

Optical coherence tomography studies provide new insights into diagnosis and prognosis of infantile nystagmus: a review.
Thomas MG, Gottlob I.
STRABISMUS
2012;20:185-90.

Acta Ophthalmologica

Endophthalmitis after cataract surgery
Reviewed by: Nana Theodorou
Aug/Sep 2013 (Vol 20 No 2)
 

Endophthalmitis is a serious infection usually following intraocular surgery. The authors looked at the frequency of postoperative endophthalmitis (PE) following cataract surgery with and without the use of postoperative antibiotics. The diagnosis of PE was made after a severe intraocular inflammation prompting sample collection and culture from the anterior chamber and vitreous. Notes were reviewed retrospectively for two periods; period one (2004-06) when patients were issued with postoperative chloramphenicol eye drops and period two (2007-10) during which antibiotics were omitted from standard postoperative practice. Five cases of PE were identified for period one (0.07%) and four for period two (0.05). The authors found no difference in the frequency of PE following cataract surgery when changing the postoperative topical medication from a mixture if corticosteroids and antibiotics to only corticosteroids. As antibiotic resistance is a growing issue these results provide further evidence to support reducing antibiotic usage.

Reference

Endophthalmitis following cataract surgery: the role of prophylactic postoperative chloramphenicol eye drops.   
Raen M, Sandvik GF, Drolsum L.
ACTA OPHTHALMOLOGICA

2013;91:118-22.

Acta Ophthalmologica

The Reykjavik eye study on exfoliation syndrome
Reviewed by: Nana Theodorou
Aug/Sep 2013 (Vol 20 No 2)
 

This study was a population based prospective cohort study. The authors looked at the incidence of exfoliation syndrome (XFS) in adults aged 50-79 years at baseline in 1996 and 12 years later. Just over 71% returned for the 12 year follow-up which included eye examination and a questionnaire. A total of 8% developed XFS in at least one eye, with women being more commonly affected than men. The incidence increased with increasing age from 6.5% (50-59 years) to 10.6% (70-79 years) at baseline. Seventy-one percent of the unilateral cases progressed to bilateral at the 12 year follow-up. Eyes with XFS at baseline were three to four times more likely to have cataract surgery during the 12 years.

Reference

Twelve-year incidence of exfoliation syndrome in the Reykjavik eye study.
Arnarsson A, Sasaki H, Jonasson F.
ACTA OPHTHALMOLOGICA

2013;91:157-62.

American Journal of Ophthalmology

Shield ulcers in vernal keratoconjunctivitis
Reviewed by: KC Madhusudhana
Aug/Sep 2013 (Vol 20 No 2)
 

Vernal keratoconjunctivitis is a chronic bilateral allergic inflammation of the ocular surface which can sometimes be complicated by shield ulcers (3-20%). In this retrospective study, the authors have assessed the clinical outcomes of shield ulcers treated with various methods. Included in the study were 193 eyes of 163 patients clinically diagnosed with vernal keratoconjunctivitis and shield ulcers. The Cameron clinical grading of shield ulcers was used to plan the treatment algorithm. Grade 1 ulcers received medical treatment alone. Grade 2 and grade 3 ulcers received either medical therapy alone or in combination with debridement, amniotic membrane transplantation (AMT), or both. In the grade 1 group, re-epithelialisation was seen in 94% eyes. In the grade 2 group, re-epithelialisation was seen in 88% of eyes that received medical treatment, in 95% of eyes that underwent debridement and in 100% of eyes that underwent AMT. In the grade 3 group, re-epithelialisation was seen in only 1.7% of eyes that received medical treatment, whereas it was seen in all eyes that underwent debridement and AMT. The mean best-corrected visual acuity after re-epithelialisation of the shield ulcer was 20/30, 20/30, and 20/40 in the grade 1, grade 2, and grade 3 groups, respectively. Recurrence and secondary bacterial keratitis were seen in 14.5% and 10% of eyes, respectively. The study shows that the grade 1 shield ulcers respond well to medical treatment alone, whereas grade 2 ulcers occasionally require additional debridement or AMT. Grade 3 ulcers are refractory to medical treatment requiring debridement and AMT for prompt re-epithelialisation.

Reference

Management, clinical outcomes, and complications of shield ulcers in vernal keratoconjunctivitis.
Reddy JC, Basu S, Saboo US, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY

2013;155(3):550-9.e1.

British Journal of Ophthalmology

Grid laser photocoagulation for macular oedema
Reviewed by: Jonathan Chan
Aug/Sep 2013 (Vol 20 No 2)
 

This is a prospective interventional consecutive study of previously untreated eyes with perfuse macular oedema (MO) over a period of 16 months for intravitreal bevacizumab (BEV) and for 29 months for grid laser photocoagulation (GLP). A total of 23 eyes in the BEV group and 21 eyes in the GLP group were studied with MO secondary to branch retinal vein occlusion (BRVO). The follow-up period was one year and patients with persistent MO after 12 months of BEV were given GLP and vice versa, and were followed-up for another 12 months. Both groups were found to have significant reduction (p<0.05) in the central retinal thickness (CRT) at 12 months, but there was delay in the GLP group. In addition, in the BEV group there was a significantly better visual outcome of best-corrected visual acuity (BCVA) compared with the GLP group (0.2 vs. 0.5 log-mar; p<0.04). During the switch over period for a non-responder, it was found that there is a further reduction of CRT for another 12 month duration. The authors concluded that from this study the BEV group results had more effective reduction of CRT of MO due to the BRVO than the GLP group. BCVA was significantly better after one year treatment in both groups and even non-responders with persistent MO would benefit from switching therapy between the two treatment modalities

Reference

Grid laser photocoagulation for macular oedema due to branch retinal vein occlusion in the age of bevacizumab? Results of a prospective study with crossover design.
Leitritz MA, Gelisken F, Ziemssen F, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY

2013;97:215-9.

Clinical and Experimental Ophthalmology

Limitations of trabeculectomy
Reviewed by: Kwesi Amissah-Arthur
Aug/Sep 2013 (Vol 20 No 2)
 

Increased subspecialisation and complexity of ophthalmic work has led to segregated training for several ophthalmic trainees around the world. An area where this is highly visible is in the surgical management of glaucoma patients. This field is fast becoming the exclusive domain of trainees interested in glaucoma. This change has some advantages as it concentrates surgical care in the hands of ophthalmologists with a specialist interest in glaucoma. However, the burden of glaucoma disease, particularly in the context of an ageing population, is such that this trend calls for more glaucoma specialists, where previously general ophthalmologists could perform several of these procedures. This retrospective study by Sun and Lee looks at trabeculectomy surgery performed by Queensland trainees over a seven year period and compares the outcomes to trabeculectomy performed by general consultants and consultants with a specialist interest in glaucoma. Success was divided into two groups; an IOP of ≤21mmHg and 15≤mmHg, visual field progression was another outcome measure. There were 248 primary trabeculectomies performed, 149 male and 99 female. Seventeen trainees performed 145 cases (59%), with a rate of 1.1 cases per trainee per year. The mean age was 68 years ±13.48. There were 181 progressive open angle glaucoma cases, 18 angle closure cases and the others were a mixture of secondary glaucoma cases. An intraocular pressure of 15mmHg without the use of topical medications was achieved in 25 out of 50 (50%) by glaucoma specialists, 24 out of 53 (45.3%) by general consultants and 68 out of 145 (46.9%) trainee cases (P=0.951). The rate of visual field progression was also statistically similar between trainees and consultants (19.5% and 21.3%), respectively. There was a difference in the case selection, with consultants performing more high-risk cases than the trainees. Medium-risk cases were similar in all groups. Complication rates in the first postoperative week were similar between consultants and trainees, the most common being wound leak 13 (5.2%) and hyphaema 15 (6.1%). There was no statistically significant difference seen between the three groups with respect to the number of cases requiring return to theatre. This paper with all its limitations due to its inherent retrospective nature shows that there is no statistically significant difference in the outcomes of trabeculectomy performed by trainees and consultants. Clearly there was good preoperative case selection in the choice of trainee-performed surgery. Given the global financial climate, and the push for more efficiency in most developed health care systems, it makes sense for trainees to be able to safely perform these procedures, particularly in the context of our ageing population. For this to happen there needs to be some change in the status quo to enable trainees access to suitable cases, to better prepare them for their role as consultants. This is more pertinent as the vast majority of glaucoma is managed in general clinics, by non-glaucoma specialist ophthalmologists.

Reference

Trabeculectomy: the limitations for registrar training.
Sun LL, Lee GA.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY

2013;41(2):135-9.

Cornea

Corneal collagen cross-linking window absorption
Reviewed by: Ms Sharmina Khan
Aug/Sep 2013 (Vol 20 No 2)
 

Three cases of microbial keratitis due to i) Pseudomonas aeruginosa ii) Acanthamoeba and iii) Strep. Pneumoniae were treated with riboflavin-UVA-light to induce corneal collagen cross-linking when there was an inadequate response to systemic and topical antibiotics, at i) one day ii) five days and iii) eight days of treatment respectively. The authors modified the original Dresden protocol, i.e. removing the corneal epithelium, application of iso-osmolar riboflavin followed by exposure to UVA light for 30 minutes. Instead used the modified ‘window absorption’ approach, which involves applying hypo-osmolar riboflavin through the epithelial defect overlying the ulcer and the remaining intact epithelium. This strategy was employed to reduce the risk of delayed epithelial healing, with use of hyposomolar solution which causes stromal swelling, thus avoiding inadvertent damage to endothelium in areas of cornea thickness less than 400um. In all three cases there was successful resolution of the infective process and with no recurrence in all three cases at three months and in the case of Acanthamoeba at six months.

Reference

Corneal collagen cross-linking window absorption.
Rosetta P, Vinciguerra R, Romano MR, Vinciguerra P.
CORNEA

2013;32:550-4.

Experimental Eye Research

Citrullinated proteins in AMD retinas
Reviewed by: Mr Graham Wallace
Aug/Sep 2013 (Vol 20 No 2)
 

Deimination is a post-translational modification that is important in the functional activity of certain proteins. Deimination is mediated by peptidyl arginine deiminase enzymes (PADs), which are induced by increase in cellular calcium levels to convert arginine residues to citrulline. The importance of PADs to disease is best seen in rheumatoid arthritis where PAD4 is linked to anti-citrullinated protein production, a marker for early disease. PAD2 is the most prevalent isoform in the nervous system and elevated levels have been linked to many neurological diseases. PAD2 is the dominant isoform in the retina. In this paper the authors analysed PAD2 levels and protein deimination in retinas from donor eyes from patients with age-related macular degeneration (AMD) and normal individuals. The results show an increase in citrullinated residues was detected in lysates from AMD retinas, however, there was no significant increase in PAD2 in either retinas or lysates. The authors comment that this may be due to reduced clearance of deiminated proteins rather than increased activity of PAD2. This data suggests that protein deimination has a role to play in AMD.

Reference

Retinal deamination and PAD2 levels in retinas from donors with age-related macular degeneration (AMD).
Bonilha VL, Shadrach KG, Rayborn ME, et al.
EXPERIMENTAL EYE RESEARCH

2013;111:71-8.

Experimental Eye Research

Ocular Tissue Database – expression profiling in the eye
Reviewed by: Mr Graham Wallace
Aug/Sep 2013 (Vol 20 No 2)
 

Gene variants have been linked to many ocular diseases and in many cases to other autoimmune or autoinflammatory diseases, suggesting common pathways. Many of these variants have been identified by microarray analysis, which has been immensely useful but has limitations due to probe bias. Moreover, gene expression profiles in healthy ocular tissue are not well understood. To address this, the authors used exon microarrays consisting of 1.4 million probe sets, giving approximately 40 probes per gene, in 10 ocular tissues, including retina, sclera and cornea from donor eyes. Expression values were compared to established public resources. The results show tissue specific gene profiles with known genes validated to confirm the results. This data, which is available on the Ocular Tissue Database (OTDB) at http://genome.uiowa.edu/otdb/ provides an important new resource to study the genetic basis of ocular tissue in health and disease.

Reference

Exon-level expression profiling of ocular tissues.
Wagner AH, Anand VN, Wang WH, et al.
EXPERIMENTAL EYE RESEARCH

2013;111:105-11.

Experimental Eye Research

β-adrenergic receptor blockade in ROP
Reviewed by: Mr Graham Wallace
Aug/Sep 2013 (Vol 20 No 2)
 

Retinopathy of prematurity (ROP) is a major cause of blindness and visual impairment in young children. The pathogenesis of ROP is considered to consist of two distinct phases of vasculogenesis and angiogenesis, the latter driven by VEGF. Recent data has also implicated the beta-adrenergic system in ROP with polymorphisms in intracellular molecules downstream of the beta-adrenergic receptor (β-AR) linked to protection and blockade of the system by propranolol inducing involution in haemangioma, a tumour associated with ROP. To address whether propranolol could affect ROP, pups were placed in high oxygen concentrations between days seven and 12 after birth and then returned to room concentrations till day 17. Propanolol was administered topically four times a day from day 12. The results show that 2% propranolol reduced VEGF and IGF-1 up-regulation due to hypoxia, driven by HIF- 1α, which was also significantly reduced. Treatment significantly reduced retinal neovascularisation. These results strongly support β-AR blockade by topical administration in inhibiting complications of ROP.

Reference

Eye drop propranolol administration promotes the recovery of oxygen-induced retinopathy in mice.
Dal Monte M, Casini G, la Marca G, et al.
EXPERIMENTAL EYE RESEARCH

2013;111:27-35.

Investigative Ophthalmology And Visual Science

Growth spurts and myopia
Reviewed by: Ms Carmel Noonan
Aug/Sep 2013 (Vol 20 No 2)
 

Several environmental factors, such as near work including reading, writing, watching TV and educational level have been associated with myopia. In addition, a history of myopia in parents or siblings also predisposes to myopia. In some studies the rate of myopia progression was fastest from ages six to nine years and girls progressed faster than boys during the ages of six to 11 years. This timing correlated with the onset of puberty, which was reported to be between 8.9 and 11.2 years. This study looked at the relationship between puberty and growth spurts using peak spherical equivalent (SE) or axial length (AL) velocity in Singapore schoolchildren. This cohort study of risk factors for myopia included 1,779 school children aged from six to 14 years. Information gathered included age of menarche, age of peak height velocity and break of voice (BOV). Tanner stage 1 for pubic hair and breast development at age twelve was categorised as late puberty, whereas stages 2 to 5 corresponded to earlier puberty. Refractive error was determined by cycloplegic auto refraction using the Canon RK-F5 and axial length was measured using the A scan biometry machine. Age of peak height velocity occurred earlier in girls than in boys. Girls with earlier peak height velocity experienced peak AL velocity and peak SE velocity approximately half a year earlier than those with later puberty. This was the same for boys. Both girls and boys who had early peak height velocity had earlier age of onset of myopia than those with later peak height velocity. Thus, variations in the onset and peak progression of myopia may be associated with height spurts.

Reference

The relationship between growth spurts and myopia in Singapore children.
Yip VC, Pan CW, Lin XY, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

2012;53:7961-6.

Investigative Ophthalmology And Visual Science

Is low contrast visual acuity assessment useful in Down syndrome and cerebral palsy?
Reviewed by: Ms Carmel Noonan
Aug/Sep 2013 (Vol 20 No 2)
 

Down syndrome (DS) and cerebral palsy (CP) are common causes of intellectual and physical impairment in children with special needs. In both DS and CP, deficits in visual acuity (VA) are known to be common; however, there is a paucity of information in the literature regarding these groups’ visual performance at low contrast. In routine clinical practice, measures of low-contrast acuity (LCA) are likely to be performed only if a patient reports symptoms of difficulties associated with poor contrast sensitivity or pathological signs that may degrade low-contrast performance. Visual acuity is a resolution measurement of high-contrast black-and-white targets and does not reflect the lower contrasts present in everyday life, including tasks such as working in subdued lighting, reading, mobility and facial recognition. Measures of contrast sensitivity have been found to predict performance in these tasks in studies of visual function in older adult populations with vision loss. High-contrast VA and LCA performance was measured monocularly using crowded Lea symbols with 45 young people with CP (mean age 11.8–4 years), 44 with DS (mean age 10.5–3 years), and 211 controls. DS and CP groups had significantly lower acuities than controls at all contrasts. Mean (+/-SD) high-contrast VA was as follows: DS=+0.39+/-0.2 logMAR; CP=+0.18+/-0.2 logMAR; controls=0.04+/-0.1 logMAR. Mean 2.5% LCA was as follows: DS=0.73+/-0.2 logMAR; CP=0.50+/-0.2 logMAR; controls=0.37+/-0.1 logMAR. For controls, the mean difference between VA and 2.5% LCA was 0.40 logMAR (95% limits of agreement, +/-0.22 logMAR). While there was a positive relation between VA and 2.5% LCA scores (linear regressions, P<0.0001), considerable variation existed, with VA explaining only 36% of the variance in LCA performance for control data. VA and LCA performance was significantly poorer in DS and CP groups than in controls, and high-contrast VA did not reliably predict low-contrast performance. Therefore, both high- and low-contrast acuity assessment are valuable to fully describe an individual’s visual function, and this may be particularly relevant in DS and CP in cases in which patients are unable to articulate visual difficulties.

Reference

Low-contrast acuity measurement: does it add value in the visual assessment of Down syndrome and cerebral palsy populations?
Little J-A, McCullough S, McClelland J, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

2013;54:251-7.

Investigative Ophthalmology And Visual Science

Population data and visual field progression rate estimation
Reviewed by: Ms Carmel Noonan
Aug/Sep 2013 (Vol 20 No 2)
 

In order to estimate visual field progression, several visual fields need to be performed over a period of time. It has been suggested that the progression rate cannot be predicted reliably until there are at least five visual fields of data. While clinicians use more than visual fields to determine the status of glaucoma control, it would be beneficial if we could improve progression rate estimators. Bayesian techniques provide a formal framework in which the population-based ‘a priori’ information (‘from before’) and empirical data from a patient can be combined to estimate a particular variable, i.e. rate progression. A priori information is quantified by using a prior distribution. What is not known is the influence of priors incorporating major risk factors for glaucoma progression. Once known, this will help us gauge the maximum benefit expected for developing prior for more minor risk factors. In this study the authors examined the benefits of having a prior distribution accounting for one of the progression’s major risk factors; whether IOP is treated; using a Bayesian estimator for progression rate. They developed their prior distribution data using published estimates of progression rates for mean deviation (MD) in db/yr on the Humphrey Field analyser (HFA) to form prior distributions reflecting either treated (Canadian Glaucoma Study; matched-prior) or untreated primary open angle glaucoma (Early manifest Glaucoma Trial; unmatched-prior). To calculate the true rate of visual field progression they created mean deviation values for 13 visual fields performed at six monthly intervals. They found that if there are less visual fields to analyse the use of a prior is useful. If there is a large series of visual fields the difference between techniques decreased. They concluded that failure to consider a major risk factor – whether or not IOP was treated – did not alter the performance of the Bayesian estimator of visual field progression.

Reference

How useful is population data for informing visual field progression rate estimation?
Anderson A, Johnson C.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE

2013;54;3:2198-206.

Investigative Ophthalmology And Visual Science

Retinal nerve fibre layer and MS
Reviewed by: Ms Carmel Noonan
Aug/Sep 2013 (Vol 20 No 2)
 

Multiple sclerosis (MS) is a neurodegenerative disease characterised by axonal injury in the central nervous system (CNS), leading to progressive neurologic deficits. Axonal damage in patients with MS can be detected and quantified at the level of the retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT). The purpose of this study was to evaluate structural and functional changes of the RNFL and correlations between these RNFL changes and disease progression or severity over a period of three years. The authors performed a prospective longitudinal study in 94 patients with MS and 50 healthy subjects. In addition to a full eye examination each subject had visual fields, OCT imaging and a visual evoked potential (VEP) test. The neurologic variables assessed were MS phenotype (relapsing–remitting, primary progressive and secondary progressive), disease duration, Expanded Disability Status Scale (EDSS), and EDSS Fvi (visual system subset of the EDSS). Significant decreases (P<0.05, t-test) were observed in the mean, superior, inferior and temporal RNFL thicknesses, and macular volume provided by OCT, and in the P100 latency of VEP of the MS group, but only in the mean and inferior RNFL thicknesses of the healthy control group.

Reference

Progressive degeneration of the retinal nerve fiber layer in patients with multiple sclerosis.
Herrero R, Garcia-Martin E, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE

2012;53:8344-9.

Investigative Ophthalmology And Visual Science

Should we all drink green tea?
Reviewed by: Ms Carmel Noonan
Aug/Sep 2013 (Vol 20 No 2)
 

It was found that green tea is neuroprotective in diabetic retinopathy. Silva et al reported that in diabetic retinopathy green tea treatment prevented alterations in the retinal glutamate / glutamine cycle, thus reducing the glutamate-metabolising enzyme (GS). It was also found to restore the glutamate transporter, glutamate receptor and GS levels, maintaining this to a level similar to the retinal of non diabetic animals. Green tea counteracts the glutamine / glutamate impairment in Muller cells, preventing oxidative stress by restoring the cysteine route. In ARPE-19 cells studies, green tea was found to protect them from oxidative stress by upregulation of claudin-1 and sealing the outer blood retinal barriers. Green tea was found to improve the function of the glutamate receptor EAAC1. Improvement in oxidative stress restores the glutamine / glutamate cycle, leading to neuroprotection of the diabetic retina with preservation of the tight junction proteins and EAAC1 expressions at RPE levels. It was reported that the increase in phosphor-nNOS with decrease in cGMP levels in diabetic animals was reversed by oral green tea. It showed that green tea can improve the efficiency of the NO / cyclic GMP pathway in models of diabetic retinal disease.

Reference

Green tea is neuroprotective in diabetic retinopathy.
Silva KC, Rosales MA, Hamassaki DE, et al.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE

2013;54(2):1325-36.

Journal of Refractive Surgery

Presbyopic inlay
Reviewed by: Dr Amit Patel
Aug/Sep 2013 (Vol 20 No 2)
 

This prospective study evaluates the outcomes of inserting the Flexivue Micro-lens corneal inlay for treatment of presbyopia. A femtosecond pocket was created at a depth of 280µm in the non-dominant eye and the inlay injected and centred on the visual axis. The authors claim that a 280µm depth was chosen due to reduced keratocyte. Although 37% of patients experienced a decrease on corrected distance acuity, none of the inlays were removed as patients were satisfied with their binocular uncorrected near and distance acuities. An increase in higher order aberration and decrease in contrast sensitivity was also noted. Despite this, >81% of patients perceived their unaided near vision as excellent and >93% of patients were reported to be spectacle independent at 12 months.

Reference

Visual outcomes and safety of a refractive corneal inlay for presbyopia using femtosecond laser.
Limnopoulou AN, Bouzoukis DI, Kymionis GD, et al.
JOURNAL OF REFRACTIVE SURGERY

2013;29:12-9.

Ophthalmic Genetics

Genetic factors in patients with primary open angle glaucoma
Reviewed by: Dr Nana Theodorou
Aug/Sep 2013 (Vol 20 No 2)
 

Glaucoma is a common form of blindness if left untreated. Genetic factors contribute to the pathophysiology of glaucoma and the prevalence of primary open angle glaucoma (POAG) seems to be higher in black or Asian populations. The authors report two polymorphisms (rs1533428 and rs12994401) on chromosome 2p to be strongly associated with POAG in an Afro-Caribbean population in Barbados, West Indies. As data with regard to the role of these polymorphisms in a Caucasian population were lacking, this study investigated a hypothetical association between these polymorphisms and POAG in a Caucasian population. In total, 723 participants were included in the study, comprising 366 patients with POAG and 357 control subjects from the southern part of Austria. Genotyping of rs1533428 and rs12994401 was performed using polymerase chain reaction. Allelic frequencies and genotype distributions of rs1533428 and rs12994401 did not show statistical significance between patients with POAG and control subjects (p<0.05). The authors concluded that rs1533428 and rs12994401 are not major risk factors for POAG for the Caucasian population.

Reference

Role of rs1533428 and rs12994401 in patients with primary open angle glaucoma in a European population.
Bachernegg A, El-Shabrawi Y, Weger M, et al.
OPHTHALMIC GENETICS

2013;34(1-2):48-51.

Ophthalmic Genetics

The role of Bcl-2 / Bcl-XL inhibitor in retinoblastoma cancer cells
Reviewed by: Dr Nana Theodorou
Aug/Sep 2013 (Vol 20 No 2)
 

Retinoblastoma (RB) is a rare childhood disease due to hereditary cancer in 40% of cases. RB seems to arise from inactivation of the tumour suppressing the RB1 gene, which is followed by additional genomic modifications leading to resistance of tumour cells to death. In this report, the authors explored the effect of ABT-737 on two human retinoblastoma cell lines, Y79 and WERI-Rb, as well as on the mouse photoreceptor cell line 661W. They observed that ABT-737 was very effective as a single agent in inducing human WERI-Rb cell apoptosis without affecting the mouse 661W photoreceptor cells. Preliminary analysis in primary mouse retinoblastoma tumour cell lines predicts high sensitivity to ABT-737. The authors postulate that ABT-737 or related compounds could be a highly effective drug in the treatment of some retinoblastomas. Further research is required in developing suitable RB profile tests.

Reference

The Bcl-2/Bcl-XL inhibitor ABT-737 promotes death of retinoblastoma cancer cells.
Allaman-Pillet N, Oberson A, Munier F, et al.
OPHTHALMIC GENETICS

2013;34(1-2):1-13.

Ophthalmology

Anterior uveitis after intravenous zoledronate (uveitis)
Reviewed by: Mr Brian Ang
Aug/Sep 2013 (Vol 20 No 2)
 

The authors report on the incidence of acute anterior uveitis in a cohort of patients after receiving an intravenous infusion of zoledronate. This was done retrospectively as part of data analysis for a large, randomised, double-masked, placebo-controlled clinical trial looking at the efficacy of zoledronate injections in fracture prevention for osteopaenic postmenopausal women. A total of 1,001 women were randomised to zolendronate, and of these, eight required review for symptomatic anterior uveitis, giving an incidence of 0.8%. Of these eight, one had bilateral anterior uveitis, while the rest had unilateral inflammation. Severe inflammation occurred in two patients. The uveitis occurred within seven days post-infusion. The uveitis resolved with intensive topical steroid and did not require any systemic therapy. There were no long-term sequelae following the uveitis. Uveitis following biphosphonate therapy is not common, but is a potentially sight-threatening complication that clinicians need to be aware of.

Reference

The incidence of acute anterior uveitis after intravenous zoledronate.
Patel DV, Horne A, House M, et al.
OPHTHALMOLOGY

2013;120:773-6.

Ophthalmology

Cataract surgery in patients with nanophthalmos
Reviewed by: Mr Brian Ang
Aug/Sep 2013 (Vol 20 No 2)
 

The authors report retrospectively on the six month results of cataract surgery in 43 eyes of 32 patients with nanophthalmos (axial length ≤20.5 mm). Cataract surgery in nanophthalmos can be challenging due to the lack of space in the anterior chamber and the increased risk of intraoperative complications including posterior capsule rupture and uveal effusion. Data from 43 eyes of 32 patients were reviewed. The median age at surgery was 69, and the median axial length was 20.01mm. Phacoemulsification was performed in 39 eyes (90.7%), extracapsular cataract extraction in three (7.0%), and in one eye, phacoemulsification was converted to extracapsular extraction. Surgery was routine and uncomplicated in 31 eyes (71.1%). Posterior capsule rupture occurred in three eyes (7.0%). Postoperatively, uveal effusion developed in four eyes (9.3%). Interestingly, two eyes still developed angle closure glaucoma after surgery, which were successfully treated with laser peripheral iridotomy and trabeculectomy respectively. Visual acuity improved in 30 eyes (69.8%), remained unchanged in six eyes (14.0%) and decreased in seven eyes (16.3%). Interestingly, the study authors did not find any beneficial effect of prednisolone, acetazolamide and mannitol on preventing uveal effusion or cystoid macular oedema. This is the largest reported case series of cataract surgery in nanophthalmic eyes and the authors conclude that although high in risk, most cases were uncomplicated and resulted in improvement in visual acuity.

Reference

Cataract surgery in patients with nanophthalmos.
Steijns D, Bijlsma WR, Van der Lelij A, et al.
OPHTHALMOLOGY

2013;120:266-70.

Ophthalmology

Coexistent ocular surface squamous neoplasia and pterygium
Reviewed by: Mr Brian Ang
Aug/Sep 2013 (Vol 20 No 2)
 

The authors report retrospectively on ocular surface squamous neoplasia (OSSN) coexisting with pterygium in South Florida (UV index 6-7). Of the 2,005 patients who underwent pterygium excision, 34 (1.7%) had coexistent OSSN. Of these 34 cases, more than half (59% or 20 cases) were unexpectedly found in histopathology of the pterygium – these were then treated with either mitomycin C, interferon eye drops or repeat surgical excision. The remaining 41% or 14 cases were pterygia with clinically suspected OSSN. There were no recurrences of OSSN in the cases of pterygia with suspected OSSN, despite the positive margins in half of the cases. However, two recurrences (10%) occurred in the unexpected OSSN group. Kaplan-Meier survival analysis demonstrated an estimated recurrence rate of 11% at one year and 24% after two years in those with unexpected OSSN. The recurrence rates were similar to that of OSSN not associated with pterygium. So while OSSN does not commonly coexist with pterygia, cases with unexpected OSSN need to be monitored carefully for recurrence.

Reference

Prevalence, treatment, and outcomes of coexistent ocular surface squamous neoplasia and pterygium.
Oellers P, Karp CL, Sheth A, et al.
OPHTHALMOLOGY

2013;120:445-50.

Orbit

A surgical approach for managing large orbitocraniofacial defects
Reviewed by: Mr Konal Saha
Aug/Sep 2013 (Vol 20 No 2)
 

This paper describes the use of microvascular free flaps to close large orbitocraniofacial defects following excision of malignant disease. The study design is a retrospective review of 58 patients suffering from a variety of conditions (most commonly cutaneous squamous cell carcinoma extending into the orbit or along the skull base) undergoing extended exenteration. Dura and / or brain were exposed in 44.8% of cases. Surgical details are not presented but the donor sites were anterolateral thigh (70.5%), forearm (24.6%) and latissimus dorsi (4.9%). Flap failure was noted in 4.9% of patients with one late failure being attributed to radiotherapy. The authors note all failures occurred in the first half of their series, suggesting there was a learning curve for the surgical team. Interestingly, two patients were noted to have diplopia despite all patients having had an exenteration. The paper provides a useful description of the outcome of a technique suited to extensive craniofacial defects. A multidisciplinary approach is required in these cases and a prolonged recovery can be expected (mean 15.3 days).

Reference

Microvascular free flap reconstruction of orbitocraniofacial defects.
Heffelfinger R, Murchison AP, Parkes W, et al.
ORBIT

2013;32(2):95-101.

Orbit

Upper eyelid skin contracture following orbiculectomy
Reviewed by: Mr Konal Saha
Aug/Sep 2013 (Vol 20 No 2)
 

This is an interesting retrospective report of a series of eight patients with essential blepharospasm who underwent upper eyelid orbiculectomy. The authors describe a limited upper eyelid orbiculectomy carried out through an upper eyelid skin crease incision involving meticulous excision of pretarsal and preseptal orbicularis oculi muscle. The procedure was reported to be effective in reducing the functional disability score. In all cases upper eyelid skin contracture was noted despite no skin excision being performed. The contracture was severe enough to cause restrictive lagophthalmos in three patients. The recommendation is to preserve upper eyelid skin in these patients even in the presence of dermatochalasis.

Reference

Skin contracture following upper eyelid orbiculectomy: is primary excision advisable?
Sagili S, Malhotra R.
ORBIT

2013;32(2):107-10.

Strabismus

Binocular vision in dyslexics
Reviewed by: Dr Fiona Rowe
Aug/Sep 2013 (Vol 20 No 2)
 

The aim of this study was to evaluate refractive errors, visual acuity, strabismus, vergence, accommodative ability and stereopsis in a group of 63 children diagnosed with dyslexia and to compare the results with values from a group of 60 non-dyslexic children. No difference was found between groups for refractive error, monocular or binocular visual acuity at either near or distance, for near point of convergence, stereopsis and fusional vergence. They found reduced monocular and binocular amplitude of accommodation. Results support that deficits of binocular coordination are the result of dyslexia itself and not an underlying cause of dyslexia.

Reference

Evaluation of aspects of binocular vision in children with dyslexia.
Wahlberg-Ramsay M, Nordstrom M, Salkic J, Brautaset R.
STRABISMUS

2012;20:139-44.

Strabismus

BT for consecutive esotropia
Reviewed by: Dr Fiona Rowe
Aug/Sep 2013 (Vol 20 No 2)
 

The authors report the outcomes after bacillus thuringiensis (BT) treatment in a series of six children with a persistent consecutive esotropia following surgical correction of intermittent exotropia. Four children had resolution of their esotropia with one or more injections. All but one patient achieved final alignment of 10PD or less at six metres with BT alone. Four patients achieved high grade stereopsis. One child required further surgery.

Reference

Botulinum toxin A treatment of consecutive esotropia in children.
Couser NL, Lambert SR.
STRABISMUS

2012;20:158-61.

Strabismus

Prevalence of anisometropia
Reviewed by: Dr Fiona Rowe
Aug/Sep 2013 (Vol 20 No 2)
 

This study aimed to determine the prevalence of anisometropia in a population with a wide age range in Iran. Analysis was undertaken for 2,947 individuals with a mean age of 29.77 years ± 17.67 years. Sixty-five percent were female. The prevalence of anisometropia was 5.6% based on a cut-off diagnosis of 1D or more. A strong correlation was found with amblyopia. Myopia and history of ocular trauma were reported as risk factors for anisometropia.

Reference

The prevalence of anisometropia in a population base study.
Ostadimpoghaddam H, Fotouhi A, Hashemi H, et al.
STRABISMUS

2012;20:152-7.

Strabismus

Restrictive strabismus
Reviewed by: Dr Fiona Rowe
Aug/Sep 2013 (Vol 20 No 2)
 

The authors report a case of a 14-year-old boy presenting since one year of age with enophthalmos, limitation of abduction, head turn and globe retraction. A provisional diagnosis of Duane’s retraction syndrome had been made followed by a possible diagnosis of congenital fibrosis of extraocular muscles (CFEOM). Orbital and cranial magnetic resonance imaging (MRI) scans revealed a structure originating in the annulus of Zinn following the pathway inferior to the optic nerve and inserting on the globe after dividing into two branches. One branch inserted into the posterior and inferior portion of the medial rectus and one into the optic nerve. Surgery did not resolve the ocular motility deficit and the abnormal structure could not be reached by the strabismus surgery approach.

Reference

Atypical restrictive strabismus secondary to an anomalous orbital structure: differential diagnosis.
Merino P, Gomez de Liano P, et al.
STRABISMUS

2012;20:162-5.

Strabismus

QoL in IDXT
Reviewed by: Dr Fiona Rowe
Aug/Sep 2013 (Vol 20 No 2)
 

The purpose of this study was to assess responses to individual items on child and proxy intermittant exotropia (IXT) questionnaire to evaluate the impact of health-related quality of life (QoL) concerns in 80 children with intermittent distance exotropia (IDXT) and including reports from parents of each child. The health-related QoL concerns with the greatest impact reported by children are shutting one eye when it is sunny, waiting for eyes to clear up and worrying about the eyes. Shutting one and worrying were also the highest rated concerns reported by the parent proxy. Younger children had lower scores than older children. Impact of concerns also differed if scored by parents. They reported older children as having lower scores with a higher proportion of high frequency responses on most questionnaire items.

Reference

Specific health-related quality of life concerns in children with intermittent exotropia.
Yamada T, Hatt SR, Leske DA, Holmes JM.
STRABISMUS

2012;20:145-51.

Acta Ophthalmologica

Lifestyle and nutrition in age-related macular degeneration
Reviewed by: Nana Theodorou
Jun/Jul 2013 (Vol 20 No 1)
 

Age related macular degeneration (AMD) is a leading cause of blindness in developed countries. This systematic review was performed for articles published during 1999 and 2010. The review focused on lifestyle modifications such as smoking cessation, increasing physical activity, avoiding obesity and reducing alcohol consumption, as well as antioxidant supplements. Meta-analyses, population-based cohort studies and case-controlled trials were included in the review. The results highlighted smoking and obesity as risk factors for AMD. The Age Related Eye Disease study was the only large-scale randomised controlled trial to show beneficial effect of a formulation of vitamins C, E, beta-carotene and zinc with copper in reducing the risk progression in patients with intermediate or advanced AMD.

Reference

Lifestyle modification, nutritional and vitamins supplements for age-related macular degeneration.
Sin HPY, Liu DTL, Lam DSC.
ACTA OPHTHALMOLOGICA
2013;91:6-11.

Acta Ophthalmologica

The use of glasses alone or combined with Bangerter filters for anisometropic amblyopia
Reviewed by: Nana Theodorou
Jun/Jul 2013 (Vol 20 No 1)
 

This randomised controlled trial compared spectacle correction alone or combined with Bangerter filters in children with anisometropic amblyopia. Eighty children (mean age, 4.4 years) with anisometropic amblyopia and a best median visual acuity (VA) in the amblyopic eye of 0.4 logMAR were randomly assigned to treatment with either spectacles or spectacles in combination with a Bangerter filter for one year. A fixed-density filter of 0.3 was used and attached to the back of the spectacle of the fellow eye and worn full time. This filter density reduced distance vision to about 0.52 logMAR in the covered eye. Both treatments began simultaneously without a period of refractive adaptation. Resolution of amblyopia was defined as a VA difference of one line or less between the two eyes. After one year, treatment with spectacles continued whilst if the VA differed by ≥2 lines, treatment with Bangerter filters was continued if originally prescribed. The main outcome measure was the median change in VA of the amblyopic eye after two years. The results showed that the median change in VA was similar between the two groups (0.4 log unit for both groups) at the two-year visit. At that time, the VA in the amblyopic eyes and the fellow eyes was 0.0 logMAR in both groups. The median anisometropia decreased in both groups (p<0.0001). The magnitude of the VA change two years after treatment with spectacles alone or combined with a Bangerter filter for anisometropic amblyopia was similar.

Reference

Two-year follow-up of a randomized trial of spectacles alone or combined with Bangerter filters for treating anisometropic amblyopia.
Agervi P, Kugelberg U, Kugelberg M, et al.
ACTA OPHTHALMOLOGICA
2013;91:71-7.

American Journal of Ophthalmology

Long-term graft rejection after corneal transplantation
Reviewed by: KC Madhusudhana
Jun/Jul 2013 (Vol 20 No 1)
 

Graft rejection is one of the commonest causes of graft failure following corneal transplantation. In this retrospective study, the authors have evaluated the risk factors for corneal graft rejection and rejection irreversibility. Included in the study were 1,438 patients who underwent corneal transplantation for optical reasons. Penetrating keratoplasty (PK) was carried out in 1,209 cases, anterior lamellar keratoplasty (ALK) in 165 cases and DSEK in 64 cases. There were 299 rejection episodes, of which 48.5% were irreversible after treatment. In multivariate analysis, recipient age, rejection risk, lens status and surgical group significantly influenced the cumulative incidence of rejection episodes. The maximum cumulative incidence of rejection episodes was found in younger recipients (aged less than 20 years) and for recipients aged 41-50 years. The cumulative incidence of rejection episodes was higher in high-risk recipients compared to low-risk recipients. It was higher in aphakic eyes and eyes with anterior chamber intraocular lenses (ACIOL) than in eyes with posterior chamber IOL and phakic eyes (p<0.01). The cumulative incidence of rejection episodes was higher in eyes with PK than in eyes with ALK (p<0.05). Stromal, epithelial and subepithelial rejection episodes were never irreversible, whereas diffuse endothelial rejection, progressive endothelial rejection (Khodadoust line), and mixed cases of rejection led to graft failure in 55%, 48% and 55% of cases, respectively.

Reference

Long-term rejection incidence and reversibility after penetrating and lamellar keratoplasty.
Guilbert E, Bullet J, Sandali O, et al.  
AMERICAN JOURNAL OF OPHTHALMOLOGY
2013;155(3):560-9.e2.

British Journal of Ophthalmology

Horizontal deviation in isolated fourth nerve palsy
Reviewed by: Jonathan Chan
Jun/Jul 2013 (Vol 20 No 1)
 

This is a retrospective study of review of the clinical records of consecutive isolated fourth nerve palsy (IFNP) patients from Kyoto University Hospital Japan, between April 2000 and June 2012. A total of 126 patients were included in this study. The authors investigated the aetiologies of these patients and classified them into five different groups; microvascular, congenital, decompensation of congenital, traumatic and others. They measured the recovery rate of the magnitude of the vertical and horizontal ocular deviation (prism dioptres) in primary position. Forty-seven percent was due to microvascular origin and 33% was due to decompensation. The recovery rate was significant in the microvascular group (92%) compared to the decompensation group (55%). The median magnitude of vertical deviation was significantly different between the microvascular group and the congenital group (5.7±3.3 vs. 13.1±11.4, p=0.028). The microvascular group includes more patients with exo-deviation, while the decompensation group includes more patients with eso-deviation (p<0.001). The authors concluded that the horizontal deviation of IFNP mainly showed exo-deviation (55%) and a degree of the horizontal deviation is useful for making a judgement between vasculopathic and decompensated IFNP.

Reference

Horizontal deviation as diagnostic and prognostic values in isolated fourth nerve palsy.
Hata M, Miyamoto K, Nakagawa S, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2013;97:180-3.

Clinical and Experimental Ophthalmology

ReGAE project findings
Reviewed by: Kwesi Amissah-Arthur
Jun/Jul 2013 (Vol 20 No 1)
 

The Holy Grail for most surgeons is to perform safe and successful surgery on every patient. In order to do this, all patient and surgical factors have to be optimised to improve patient outcome. This prospective, consecutive, observational, non-comparative study by Agrawal et al. aims to identify baseline (pre-surgical) indices that influence the result and survival of augmented trabeculectomy surgery in African-Caribbean (AFC) patients. The Birmingham ‘ReGAE’ (Research into Glaucoma and Ethnicity) project is an ethnically sensitive research study aiming to prevent avoidable blindness among the diverse ethnic populations in the UK. This is the ninth paper in the series. In this paper, 47 AFC patients with a minimum of 24 months follow-up post-trabeculectomy were studied. A fornix based augmented trabeculectomy with 0.4mg/ml or 0.2mg/ml of Mitomycin-C (MMC) was performed. Surgical success was defined as intraocular pressure (IOP) reduction to ≤21mmHg, ≤18mmHg and ≤15mmHg without glaucoma medication. A qualified success was defined as IOP reduction to ≤21mmHg, ≤18mmHg and ≤15mmHg with or without glaucoma medication. Failure was defined as a drop in the IOP to below 6mmHg or where the success criteria were not met on two successive visits after three months. Excluding bleb needling revision, the time point to IOP lowering surgical intervention following trabeculectomy was documented as time to treatment failure. Univariate and multivariable logistic regression was used to analyse survival factors. Trabeculectomy survival at 12, 24 and 36 months was significantly decreased with the use of preoperative acetazolamide, pseudophakic status and higher preoperative intraocular pressure (P<0.05). In pseudophakic eyes, there was a lower qualified success rate when aiming for an intraocular pressure ≤15mmHg at two years post-trabeculectomy, the odds ratio being 12. The IOP factor most associated with trabeculectomy failure was the immediate preoperative IOP. Interestingly, MMC concentration, gender, grade of surgeon, number of preoperative medications and preoperative CDR were not found to be statistically significant for failure. AFC patients are deemed as having a higher risk of trabeculectomy surgery failure. This study reminds ophthalmologists of some of the factors already known to influence surgical success in these patients: namely preoperative IOP; previous cataract surgery; and use of oral acetazolamide. The authors show that in preoperative pseudophakic eyes, MMC concentration and duration was not statistically significant in influencing trabeculectomy survival. Above all, this study highlights the need for a patient-centred and individualistic approach to the management of these complex and high-risk cases to improve surgical survival rates.

Reference

ReGAE 9: baseline factors for success following augmented trabeculectomy with mitomycin C in African-Caribbean patients.
Agrawal P, Shah P, Hu V, et al.
CLINICAL & EXPERIMENTAL OPHTHALMOLOGY
2012;41(1):36-42.

Cornea

Big bubble enlargement for PK
Reviewed by: Sharmina Khan
Jun/Jul 2013 (Vol 20 No 1)
 

Of the three main techniques described (Anwar’s big bubble, Melles’ dissection and air / saline stromal dissection) Anwar’s big-bubble technique results in a comparable visual outcome with penetrating keratoplasty (PK), due to baring of Descemet’s membrane, whereas the other techniques leave variable residual stromal tissue on Descemet’s that can result in graft-host interface haze. The bubble margin can be white representing air in an intrastromal plane or clear representing bare Descemet’s. Extension of a white margin is carried out using a blunt Melles’ spatula to the trephination edge. The clear margin bubble that has not fully extended can be treated with further injection of an air bubble, which due to the pressures involved can lead to Descemet’s rupture, and so the author’s describe a novel technique involving the use of a cohesive ophthalmic viscosurgical device (OVD) to gently and in a more controlled manner extend the bubble edge to trephination size and with success in their hands have avoided conversion to PK. This modification in the big-bubble technique is certainly worth a go to reduce PK conversion rates. However, it should be noted that the authors use a sharp 30G cannula for dissection, whereas others such as Donald Tan have reported the use of a blunt wider bore cannula with reduced conversion to PK when employing the big-bubble technique.

Reference

Enlarging the big-bubble during deep anterior lamellar keratoplasty.
McKee HD, Jhanji V, Brahma AK.
CORNEA
2013;32:520-2.

Current Eye Research

Pigment dispersion glaucoma induced by intraocular lens haptics
Reviewed by: Khadijah Basheer
Jun/Jul 2013 (Vol 20 No 1)
 

This retrospective study looked at six eyes of Chinese patients where single piece acrylic (SPA) intraocular lenses (IOLs) were placed in the sulcus and the incidence of pigment dispersion syndrome and glaucoma. Patients were included over six years with an average age of 52 years. They collected information on IOL type, interval between cataract surgery and occurrence of pigment dispersion, visual acuity, intraocular pressure, examination findings, anti-glaucoma medication and surgical interventions. Gonioscopy was used to visualise pigment deposition in the anterior chamber and optical coherence tomography (OCT) to investigate the relationship between the IOL and the iris. IOLs that were removed and exchanged were examined with light microscopy and scanning electron microscopy. All patients had signs of pigment dispersion within 30 days. Pigment deposits were noted on the optic of the IOLs in all patients and iris transillumination defects were noted where the haptic touched the posterior iris. Gonioscopy revealed dense pigmentation deposited in the inferior anterior chamber angle more than in the fellow eye. All patients required at least one eye drop to treat high IOPs and two patients required trabeculectomies. Examination of explanted IOLs with microscopy revealed dense pigmentation on the IOL optic and rough IOL edges most likely responsible for the observed chafing effects. Similar reports have found corresponding results in Caucasian patients; this is the first paper to include Asian eyes. This study demonstrated development of secondary glaucoma within one month of sulcus IOL insertion compared to previous papers of mainly pigment dispersion syndrome. This may be due to the higher amounts of pigment found in the iris of Asian patients. This study, although it had a small sample size, demonstrates the importance of recognising the potential complications of placing single piece IOLs in the sulcus. IOLs should be positioned in the capsular bag or if sulcus fixation is necessary a three-piece or specifically designed one piece sulcus IOL should be used instead.

Reference

Pigment dispersion glaucoma induced by the chafing effect of intraocular lens haptics in Asian eyes.
Hong Y, Sun YM, Qi H, et al.
CURRENT EYE RESEARCH
2013;38:358-62.

Experimental Eye Research

Proteomic analysis of proliferative diabetic retinopathy
Reviewed by: Graham Wallace
Jun/Jul 2013 (Vol 20 No 1)
 

Diabetic retinopathy (DR) is a chronic disease due to chronic exposure to hyperglycaemia. The proliferative stage of DR, PDR, is characterised by retinal neovascularisation. DR has been increasing in the general population due to increasing life-expectancy. The aetiology of DR is still not fully elucidated in part due to the lack of a reliable animal model. Recent advances in the analysis of protein profiles in body fluids, known as proteomics, have been incorporated in studies of small volumes of vitreous fluid from patients with PDR. An increase in molecules involved in angiogenesis have been identified. In this study vitreous fluid from eight patients with PDR and eight samples from normal human eyes donated for transplant were analysed by reversed phase high-performance liquid chromatography coupled to electro spray ionisation tandem mass spectrometry. The results identified 96 differentially expressed proteins, 37 upregulated in PDR, 59 down-regulated. Pathway analysis showed glycolysis / gluconeogenesis, coagulation and complement pathways were most represented. This altered expression was confirmed by western blot for several of the identified proteins. These data provide insight into mechanisms involved with PDR and may suggest new therapeutic options. Secondly, this work supports the use of global analysis of ocular fluids by ‘omics’ technology to determine new pathways and processes involved in ocular disease. In particular it demonstrates that small volumes of ocular fluids can be used in the analysis platforms

Reference

Differentiating vitreous proteomes in proliferative diabetic retinopathy using high-performance liquid chromatography coupled to tandem mass spectrometry.
Wang H, Feng L, Hu J, et al.
EXPERIMENTAL EYE RESEARCH
2013;108:110-9.

Experimental Eye Research

Zebra fish analysis of CORD6
Reviewed by: Graham Wallace
Jun/Jul 2013 (Vol 20 No 1)
 

Cone-rod dystrophies are a genetically heterogeneous group of retinopathies, that arise from an array of variants in genes encoding components of the photo transduction cascade and visual cycle. Cone-rod dystrophy 6 (CORD6) is a severe autosomal dominant form of disease caused by mutations in the gene encoding retinal guanylate cyclase 1 (RETGC1), a membrane bound cGMP synthetase, involved in opening ion channels in photoreceptor outer segments. As clinical samples are rare in this paper mutant RETGC1 was expressed in zebra fish to investigate its effect on retinal morphology and function. The results showed that mutant RETGC1 expression resulted in aberrant cone morphology and reduced density. This was characterised by reduction in photoreceptor nuclei, thickness of the outer nuclear layer and rod outer segments, particularly in the central retinal. These studies demonstrate how mutations in RETGC1 may lead to CORD6, but also show the potential of using zebra fish, a quick and reliable model system, for investigating ocular disease.

Reference

Transgenic zebra fish expressing mutant human RETGC1 exhibit aberrant cone and rod morphology.
Collery RF, Cederlund ML, Kennedy BN.
EXPERIMENTAL EYE RESEARCH
2013;108:120-8.

Investigative

Macular pigment augmentation and visual performance
Reviewed by: Carmel Noonan
Jun/Jul 2013 (Vol 20 No 1)
 

The aim of this study was to investigate changes in macular pigment optical density (MPOD) and visual performance following supplementation with different macular carotenoid formulations. Mesozeaxanthin (MZ), lutein (L) and zeaxanthin (Z) are concentrated in the inner layers of the primate maculae, known as macular pigment (MP). The presence of MP is hypothesised to protect against macular degeneration and to enhance vision. Recent evidence suggests that, in terms of antioxidant properties, MZ appears to be the most potent of the macular carotenoids. Thirty-six subjects were included in this single-masked, randomised, placebo controlled trial. They were divided into three intervention groups: group 1; L + Z supplements, group 2; MZ, L and Z supplements and group 3; placebo. All had a full range visual performance testing and MP measurements at baseline, three months and six months. Macular pigment was measured using the Macular Densitometer across 0.25, 0.5, 1, 1.25 and 3 degrees from centre of fovea. Visual performance was measured using Log MAR at 4m. Contrast sensitivity was measured using a functional acuity contrast test (Optec6500 Vision Tester) under mesopic and photopic conditions, with and without glare. The results showed a significant increase in MPOD at three months in group 2 only at all eccentricities. There was no significant change in best corrected visual acuity in any group at three months. However, student t test, showed a significant improvement in BCVA at six months in group 2. Group 2 also showed a significant improvement in contrast sensitivity (with and without glare), across a range of spatial frequencies at six months, most notably under mesopic conditions. Group 1 showed an improvement in contrast sensitivity at six months at spatial frequency of 6cpd. There was no improvement in any parameters of visual performance observed in the placebo group. The study concluded that supplementation with all three carotenoids potentially offered advantages over preparations lacking MZ both in terms of MPOD and visual performance.

Reference

The impact of macular pigment augmentation on visual performance using different carotenoid formulations.
Loughman J, Nolan JM, Howard AN, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(12):7871-80.

Investigative Ophthalmology and Visual Science

Effect of refractive error on retinal vessel calibre
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

The study aimed to validate the effect of refractive error on retinal vessel calibre measurement by assessing the correlation of retinal vessel calibre between right and left eyes in 214 12-year-old children with emmetropia compared with those with anisometropia: 35 with right-left difference <2D and 32 with differences >2D. The findings indicate that refractive errors >2D can lead to a detectable measurement error in retinal vessel calibre measurements and therefore correction of refractive error is necessary. 

Reference

Right and left correlation of retinal vessel calibre measurements in anisometropic children; effect of refractive error.
Joachim N, Rochtchina E, Tan AG, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(9):5227-30.

Investigative Ophthalmology And Visual Science

Gene expression in extraocular muscles
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

A comparison of gene expression was made by using microarrays and quantitative polymerase chain reaction (PCR) on extraocular muscle samples. Findings of a considerable number of significant up and down regulated genes point to a major contribution of the extraocular muscle itself in common forms of strabismus. Decreases in expression of contractility genes and increases of extra cellular matrix-associated genes indicate imbalances in extraocular muscle structure.

Reference

Differences in gene expression between strabismic and normal human extra ocular muscles.
Altick AL, Feng CY, Schlauch K, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(9):5168-77.

Investigative Ophthalmology And Visual Science

PROMs and POEMs in glaucoma care
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

The authors aimed to develop a patient-reported outcome (PRO) instrument for use in clinical practice by assessing the patient perspective on patient-reported outcome measures (PROMs), what a PROM for glaucoma should measure and the feasibility of such measurement. The participants’ PROM specification was compared to the items included in existing instruments available in the public domain to establish if an ideal instrument already exists or, if not, to develop one. Focus groups with 71 participants and 23 eye care staff as facilitators were held. Thematic coding was undertaken. The contributors proposed a short, practical and useful questionnaire including measurement of health outcome and patient experience. No instrument in the public domain was found to cover all domains, particularly knowledge and understanding. The study proposes a new instrument for patient-reported outcome and experience (POEM) to address fear of blindness, acceptability of treatment and side-effects, impact on daily life and three aspects of experience of safety, respect and understanding.

Reference

Moving from PROMs to POEMs for glaucoma care: a qualitative scoping exercise.
Somner JE, Sii F, Bourne RR, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(9):4354-62.

Investigative Ophthalmology And Visual Science

Visual characteristics of elderly night drivers
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

The authors report on the characteristics of older people who continue to drive and those who restrict their night driving based on driving data collected from a real time driving monitor system (DMS). Data was provided by 990 individuals. The DMS was a custom built device installed in the car for five days. A higher number of males were found to drive at night, along with those with better visual acuity and contrast sensitivity. More individuals drove more at night in winter. Those who drove more miles tended to drive at night as well as patients who were younger and who had better cognitive outcomes.

Reference

Visual characteristics of elderly night drivers in the Salisbury Eye Evaluation Driving Study.
Kaleem MA, Munoz BE, Munro CA, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(9):5161-7.

Journal of Glaucoma

Daily or alternate day use of travaprost?
Reviewed by: Lorraine North
Jun/Jul 2013 (Vol 20 No 1)
 

The authors present the findings of a pilot study comparing daily use versus alternate day use of travoprost 0.004% in lowering intraocular pressure (IOP) in patients with ocular hypertension. They recruited 14 patients over 60 years of age with IOPs between 21 and 32mmHg, no optic disc cupping or visual field loss and all patients had best corrected visual acuity of 6/36 or better in each eye. The patients also had central corneal thicknesses of <590 microns and open angles. Patients were randomised into two groups, travoprost once daily and travoprost once every other day alternating with artificial tears eye drops. Both patients and examiners were masked and the IOP was measured by one examiner at around 9am and 4pm at weeks, one, two, four, eight and 12 weeks after starting treatment. The authors found that in both groups the IOP was significantly reduced and the difference between the groups was not statistically significant. Alternate day use of travoprost is shown to be as effective as its daily use in lowering the IOP in patients with ocular hypertension. The study has some limitations, however, which the authors describe, which include the small sample size and short-term follow-up.

Reference

A short-term randomized clinical trial of daily versus alternate day use of travoprost 0.004% in the treatment of ocular hypertension.
Khairy HA, Khaled S-A.
JOURNAL OF GLAUCOMA
2013;22:123-6.

Journal of Glaucoma

Fixation behaviour in POAG
Reviewed by: Lorraine North
Jun/Jul 2013 (Vol 20 No 1)
 

A prospective cross-sectional study of 27 patients (39 eyes) with primary open angle glaucoma (POAG) were recruited to this study to assess the fixation behaviour in early and late stage using microperimetry. Thirteen normal patients (22 eyes) were recruited into the control group. The fixation behaviour and retinal sensitivity was analysed. The authors found that macular sensitivity and fixation stability were significantly reduced in early and moderate POAG when compared to normal eyes. Assessing fixation stability could potentially help to identify glaucoma in its early stage.

Reference

Fixation behaviour in primary open angle glaucoma at early and moderate stage assessed by the microperimeter MP-1.
Shi Y, Liu M, Wang X, et al.
JOURNAL OF GLAUCOMA
2013;22:169-73.

Journal of Pediatric Ophthalmology and Strabismus

Autorefractor comparison
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

The aim of this study was to compare the results of different refraction measurement devices including a table-mounted autorefractor, videoretinoscopy and a hand-held autorefractor with cycloplegic refraction in school aged children to evaluate the usability and reliability of these devices in measuring refractive errors. Two hundred eyes of 100 children aged five to 15 years were assessed. The mean spheric values and spherical equivalent values of the non-cycloplegic table mounted autorefractor were found to be significantly lower and those of the cycloplegic autorefractor were significantly higher than cycloplegic refraction (CR). There was no significant difference for the hand-held autorefractor and CR. All devices correlated with each other. Sensitivity in diagnosis of myopia was low but sensitivity for diagnosis of hypermetropia and astigmatism was high for the table mounted and hand-held autorefractors.

Reference

A comparison of different auto refractors with retinoscopy in children.
Oral Y, Gunaydin N, Ozgur O, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY & STRABISMUS
2012;49:370-7.

Journal of Pediatric Ophthalmology and Strabismus

INO surgery
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

The authors used a variation of the Jensen’s procedure with transfer of the superior and inferior rectus muscles to the medial rectus in addition to a lateral rectus recession and report the outcomes of using this procedure for surgical correction of internuclear ophthalmoplegia (INO). Five patients were included with INO due to stroke and multiple sclerosis (MS) (three bilateral, one unilateral and one with 1½ syndrome). The results indicate that this is an effective surgical option with four of five cases rendered orthotropic and one patient with 2PD of exo. Four patients had complete resolution of diplopia and one had intermittent vertical diplopia.

Reference

Transposition surgery for internuclear ophthalmoplegia.
Nathan NR, Donahue SP.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY & STRABISMUS
2012;49:378-81.

Journal of Refractive Surgery

Scleral cross-linking
Reviewed by: Amit Patel
Jun/Jul 2013 (Vol 20 No 1)
 

This experimental study was aimed at evaluating the biomechanical difference of human scleral collagen cross-linking (CXL) by comparing different riboflavin-instilling methods and different cross-linked regions (equatorial and posterior sclera). Fifteen donor human eyes were randomly divided into five groups. One group, in which CXL was not applied, served as the control group. In the remaining four groups, 0.1% riboflavin solution was instilled on the scleral surface for five, 10, 20, or 30 minutes, respectively, followed by 30 minutes of ultraviolet A irradiation. The equatorial and posterior scleral strips in each eye were dissected. Stress-strain measurements of all scleral strips were performed by a biomaterial tester. Young modulus was calculated at 8% strain. Data of the stress and Young modulus in different regions and groups were compared using one-way analysis of variance. Under a 1mm/minute stretching, the sclera exhibited an exponential stress-strain behavior. The stress and modulus of equatorial and posterior sclera after CXL gradually increased with riboflavin instillation before surgery. No statistical difference was noted in the modulus between 20 and 30 minutes riboflavin infiltration after CXL (P>.05). The authors extrapolate that the equatorial scleral CXL may be a good choice for the treatment of progressive myopia. Previous studies have shown retinal damage with shorter duration of riboflavin instillation and the authors therefore recommended that 20 minutes of riboflavin infiltration before CXL is safe and effective. Whilst there may not be any difference in Young’s modulus between these times, the study did not assess retinal function and hence safety may be questionable.

Reference

Regional biomechanical properties of human sclera after cross-linking by riboflavin/ultraviolet A.
Wang M, Zhang F, Qian X, Zhao X.
JOURNAL OF REFRACTIVE SURGERY
2012;28(10):723-8.

Journal of Refrective Surgery

Cross-linking in children and adolescents
Reviewed by: Amit Patel
Jun/Jul 2013 (Vol 20 No 1)
 

This is a retrospective study looking at 59 eyes of 42 children and adolescents (aged nine to 19 years) that underwent collagen cross-linking (CXL) for progressive keratoconus. Progression was determined by an increase of 1 diopter (D) in maximal keratometry (Kmax) over a 12 month period. All patients had stromal thickness >400µm. Standard epithelium off cross-linking was performed and computerised test of dynamic visual acuity (CDVA), Kmax, corneal thickness and keratoconus index (KI) were measured. Follow-up was up to 36 months (mean follow-up: 26.3 months [range: 12 to 36 months]). Fifty-two eyes were treated and CDVA, Kmax and KI changed significantly over the follow-up period. However, Kmax showed a tendency of progression after three years. CDVA showed a similar effect and the reduction in corneal thickness had no lasting effect. One eye required repeat treatment and two eyes showed delayed epithelial healing. The authors conclude that CXL is safe and effective in children and adolescents but the effect may not last as long as it does in adults. Although they suggest that one should not wait for documented progression prior to treatment, the results of the study do not support this statement. 

Reference

Progression of keratoconus and efficacy of corneal collagen cross-linking in children and adolescents.
Chatzis N, Hafezi F.
JOURNAL OF REFRACTIVE SURGERY
2012;28:753-8.

Ophthalmic Genetics

The molecular diagnosis of retinoblastoma
Reviewed by: Nana Theodorou
Jun/Jul 2013 (Vol 20 No 1)
 

Retinoblastoma (RB) is a rare childhood disease due to hereditary cancer in 40% of cases. Molecular analysis is important since there is a risk for secondary tumours and for RB predisposition in relatives. The most common presenting signs are leukocoria (54%) and strabismus (19%) which correlate with a high survival rate of the patient in developed countries and a poor ocular survival rate (9–17%). RB is caused by mutations in the RB1 tumour suppressor gene (13q14). A total of 144 families were studied over a period of 20 years. Five patients developed a second non-ocular tumour in adult life and six patients died. At risk haplotypes were identified in 11 familial and 26 sporadic cases, being useful for detection of asymptomatic carriers, risk exclusion from relatives and uncovering RB1 re-combinations. Ten large deletions were identified in six bilateral / familial and four unilateral retinoblastoma cases. Small mutations were identified in 29 cases, being the majority nonsense / frameshift mutations. Genotype-phenotype correlations confirm that the RB presentation is related to the type of mutation, but some exceptions may occur and it is crucial to be considered for genetic counselling. This study enabled the authors to obtain information about molecular and genetic features of patients with RB in Argentina and changes in methodology throughout the study period allowed a gradual increase in the rate of mutation detection.

Reference

Spectrum of RB1 mutations in Argentine patients: 20-years experience in the molecular diagnosis of retinoblastoma.
Ottaviani D, Parma D, Giliberto F, et al.
OPHTHALMIC GENETICS
2013;Epub ahead of print.

Ophthalmic Plastic & Reconstructive Surgery

Management of giant fornix syndrome
Reviewed by: Vinod Gauba
Jun/Jul 2013 (Vol 20 No 1)
 

The article describes a surgical technique for the treatment of patients with chronic relapsing conjunctivitis, corneal epitheliopathy and ptosis secondary to giant fornix syndrome. The authors perform a retrospective review of six cases diagnosed with giant fornix syndrome who were treated with an extensive conjunctivoplasty, resection of redundant conjunctiva along with subconjunctival antibiotic injection. All six patients achieved resolution of their symptoms and some even achieved a two or more line improvement in best corrected visual acuity. Further evaluation of the technique is required to establish if modification of the posterior lamella increases the incidence of entropion or dry eye.

Reference

A novel surgical technique for the treatment of giant fornix syndrome.
Nabavi C, Long J, Compton C, Vicinanzo M.
OPHTHALMIC PLASTIC & RECONSTRUCTIVE SURGERY
2013;29(1):63-6.

Ophthalmologica

Preoperative bevacizumab in neovascular glaucoma drainage surgery
Reviewed by: Ticiana Criddle
Jun/Jul 2013 (Vol 20 No 1)
 

This retrospective study assessed the efficacy of preoperative intravitreal bevacizumab (IVB) injection in the treatment of neovascular glaucoma (NVG) with Ahmed glaucoma valve (AGV) implantation. Forty-one consecutive patients (41 eyes) were reviewed, 19 patients in the study group received IVB seven to 14 days before surgery and were compared to 22 patients in the control group who had AGV implant without preoperative bevacizumab. No significant differences were found in patients' demographics and baseline characteristics. In both groups, postoperative visual acuity was similar and there was a statistically significant decrease in postoperative intraocular pressure (IOP). Surgical success rate in the bevacizumab pre-treatment group (79%) was higher than the control group (64%), although this was not statistically significant. At 12 months’ follow-up, patients in the study group were using significantly less antiglaucoma medications (p=0.003). The authors suggest that surgery should be performed within five to seven days after IVB administration and that a second injection could be given one to two weeks after the operation. Unfortunately, possibly due to the small sample size, the results did not attain significance, although the trend was encouraging. This highlights the potential benefits for using bevacizumab in association with Ahmed valve implantation in neovascular glaucoma. 

Reference

Effect of intravitreal bevacizumab injection before Ahmed glaucoma valve implantation in neovascular glaucoma.
Sevim MS, Buttanri IB, Kugu S, et al.
OPHTHALMOLOGICA

Ophthalmology

Brow ptosis after temporal artery biopsy
Reviewed by: Brian Ang
Jun/Jul 2013 (Vol 20 No 1)
 

The authors report on the complications experienced by a cohort of patients undergoing temporal artery biopsy (TAB). The area temporal artery was mapped with Doppler ultrasound and the TAB done under local anaesthesia. Patients were followed up for one year after the procedure. Seventy-seven TABs were performed in 70 patients over 17 months. Complications occurred in 22.6% of TABs. Two patients (2.7%) developed postoperative infection, while 16% developed postoperative frontalis dysfunction with brow ptosis. Most of these resolved over several months (average 4.43 months), but 4% showed no improvement after six months. The authors noted that incisions greater than 34mm posterior to both the lateral brow and lateral orbital rim were protective against brow ptosis. However, the length of incision or biopsy sample had no bearing on brow ptosis, thereby not justifying the rationale for shortening the incision or biopsy sample length. The results from this study show brow ptosis following TAB to be reasonably common, and should therefore be included in the informed consent process.

Reference

Brow ptosis after temporal artery biopsy: incidence and associations.
Murchison AP, Bilyk JR.
OPHTHALMOLOGY
2012;119:2637-42.

Orbit

External vs. endonasal DCR - a questionnaire survey
Reviewed by: Konal Saha
Jun/Jul 2013 (Vol 20 No 1)
 

The authors report on the results of a questionnaire survey sent to American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) members asking for information regarding preference of endonasal versus external dacryocystorhinostomy (DCR) and their rationale. Details on the surgeon’s experience and number of procedures performed were included. The literature reports ever increasing success rates for endonasal DCR – approaching 99%. This has risen from rates of 59% in earlier reports and has often been stated by proponents as why external DCR is preferred over endonasal. The survey shows that external DCR is offered by a higher proportion of ASOPRS members (93.9% vs. 63.1% offering endonasal) and they report a higher failure rate with endonasal DCR (35.6% vs. 5.8% with regard to tearing and 13.2% vs. 1.0% with regard to postoperative dacryocystitis). The success rates for endonasal DCR reported in this survey do not reflect success rates quoted in recent publications, which suggest equivalency; reasons for this may include the variety of techniques employed in the endonasal approach.

Reference

Current preferences and reported success rates in dacryocystorhinostomy amongst ASOPRS members.
Barmettler A, Erlich J, Lelli Jr G.
ORBIT
2013;32:20-6.

Orbit

The distribution of biopsied lacrimal gland pathology presenting to a tertiary referral centre in Singapore
Reviewed by: Konal Saha
Jun/Jul 2013 (Vol 20 No 1)
 

This paper described the distribution of pathology detected in patients undergoing lacrimal gland biopsy in a tertiary referral centre. It is a retrospective case review of 69 consecutive patients. The most common diagnosis was chronic dacryoadenitis (46%) followed by lymph proliferative disease (38%). One patient was noted to have adenoid cystic carcinoma. The authors emphasise the value of lacrimal gland biopsy in making a diagnosis and highlight the need for onward referral to a rheumatologist in those patients with chronic dacryoadenitis since over half of patients had a specific systemic inflammatory condition (Sjogren’s, hyperthyroidism, Wegener’s). Those with lymph proliferative disease warrant referral for investigation since one third of patients had systemic lymphoma. Interestingly, radiological investigations are not mentioned in this paper. Traditionally, computed tomography (CT) and magnetic resonance imaging (MRI) imaging have been valuable investigations for these patients to distinguish between various pathologies, perhaps most importantly, malignant versus non malignant epithelial tumours.

Reference

A survey of the histopathology of lacrimal gland lesions in a tertiary referral centre.
Tao L, Seah LL, Choo CT, et al.
ORBIT
2013;32:1-7.

Retina

Antiangiogenic therapy for ROP
Reviewed by: Nikolaos D Georgakarakos
Jun/Jul 2013 (Vol 20 No 1)
 

The purpose of this small, prospective, interventional, noncomparative case study is to evaluate the ocular function systemic development in premature infants treated with intravitreal bevacizumab injections (0.05 mL, 1.25mg 1mm from the limbus with a 27G needle) for retinopathy of prematurity (ROP) over a period of five years. The primary outcome was visual acuity in 18 eyes of 13 consecutive patients divided into three groups: Group 1 – stage 4 unresponsive to previous conventional treatment (n=4); Group 2 – conventional treatment was not possible due to poor visualisation of the fundus (n=5); Group 3 – newly diagnosed prethreshold or threshold ROP (n=9). All patients showed initial regression of neovascularisation. One patient was treated with a repeat bevacizumab injection for recurrence of the neovascularisation. Median vision was 20/25 (excluding two eyes that required surgery) and the ERG was normal in four eyes without RD. One patient showed delay in growth and neurodevelopment. In conclusion, this study suggests a role of intravitreal bevacizumab in ROP patients with poor fundus visualisation or cases where the conventional treatment option has failed and provides important information about the long-term effects and safety of the drug. The main limitation is the small number of participating subjects and larger randomised controlled studies are required to investigate the full spectrum of safety profile and long-term effects of intravitreal bevacizumab.

Reference

Long term effect of antiangiogenic therapy for retinopathy of prematurity: up to 5 years follow up.
Martinez-Castellanos MA, Schwartz S, Hernandez-Rojas ML, et al.
RETINA
2013;33(2):329-38.

Strabismus

Acute loss of vision after strabismus surgery
Reviewed by: Fiona Rowe
Jun/Jul 2013 (Vol 20 No 1)
 

A 61-year-old individual underwent routine recession / resection for consecutive exotropia. Immediately postoperatively the patient noticed painless visual loss. Examination revealed no perception of light, relative afferent pupillary defect, marked optic disc swelling with scattered splinter haemorrhages. Review of the anaesthetic records revealed two hypotensive episodes, the first after induction of anaesthesia and the second 30 minutes later, which lasted for 10 minutes each. The vision did not recover.

Reference

Visual loss due to NAION immediately following routine strabismus surgery under general anaesthetic – a case report.
Tsagkataki M, Rowlands A.
STRABISMUS
2012;20:121-3.

Acta Ophthalmologica

Cataract surgery with IOL in patients with juvenile idiopathic arthritis
Reviewed by: Nana Theodorou
Apr/May 2013 (Vol 19 No 6)
 

Cataract is a common complication of uveitis in patients with juvenile idiopathic arthritis. Managing these patients can be challenging due to the postoperative risk of complications. Sixteen patients notes were retrospectively analysed to review the effectiveness of intraocular lens (IOL) implantation. All patients received IOL implantation and an intraoperative triamcinolone acetonide injection. Systemic immunosuppressive therapy was carried out pre- and postoperatively. Patients were followed up for regular appointments at two days, six weeks and one year. The final visit included best corrected acuity, slit-lamp examination, applanation tonometry and ophthalmoscopy. After surgery presence of cystoid macular oedema, papilloedema, ocular hypertension and hypotony did not increase. Visual acuity was improved in all patients and seven patients developed secondary capsular opacification. The authors conclude that IOL can be used in selected well-controlled patients with juvenile idiopathic arthritis.

Reference

Favourable outcome after cataract surgery with IOL implantation in uveitic associated with juvenile idiopathic arthritis.
Grajewski RS, Zurek-Imhoff B, Roesel M, et al.
ACTA OPHTHALMOLOGICA
2012;90:657-62.

Acta Ophthalmologica

The effect of refractive surgery on the visual cortex
Reviewed by: Nana Theodorou
Apr/May 2013 (Vol 19 No 6)
 

Anisometropia has been linked to the development of amblyopia. This study looked at two anisometropic and two isometropic myopic patients who have had refractive surgery. Refractive surgery consisted of LASIK and photorefractive keratectomy (PRK). The anisometropic patients only had their myopic eye corrected, whilst the isometropic myopes had both eyes corrected. Multifocal functional magnetic resonance images were conducted pre- and postoperatively for the four patients and two controls without refractive surgery. The mffMRI results indicated that anisometropic eyes showed 65% reduced amount of voxels in representing the foveal stimulus region data at 12 months postoperatively. In unoperated anisometropic eyes the value was 86% and in myopic patients and controls 31% and 1% respectively. Visual acuity improved postoperatively for the anisometropic eyes ranging from 0.1 to 0.2 LogMAR units. The authors postulate that the findings may indicate evidence for changes in the primary visual cortex. The study only employed a small select number of participants and in the anisometropic group only mild anisometropia was present. More evidence is required in larger scale studies and with a range of anisometropia for statistical significant findings.

Reference

Refractive surgery in anisometropic adult patients induce plastic changes in primary visual cortex.
Vuori E, Vanni S, Henriksson L, et al.
ACTA OPHTHALMOLOGICA
2012;90:669-76.

Archives Ophthalmology

IOP monitoring with a contact lens
Reviewed by: Lorraine North
Apr/May 2013 (Vol 19 No 6)
 

The aim of this study was to examine the safety, tolerability, and reproducibility of intraocular pressure (IOP) patterns during repeated continuous 24-hour IOP monitoring with a contact lens sensor in 40 patients. The patients were studied in two study sessions each one week apart. The contact lens sensor (CLS) was inserted after full ophthalmological examination and visual fields and the patients were asked to complete a logbook of daily activities every 30 minutes and sent home. Twenty-four hours later they returned and were asked to score comfort level and then the lens was removed. This was repeated one week later. The most frequent reported adverse events were blurred vision, hyperaemia of the bulbar and palpebral conjunctiva and superficial punctate keratitis. All resolved within 24 hours after contact lens removal. Good tolerability was reported by the authors and fair to good reproducible IOP patterns were recorded. However, the statistical analysis was limited and it is also possible that the reproducibility of IOP patterns may have been higher in a controlled environment. The authors suggest that that the CLS provides a safe and well tolerated approach to 24 hour IOP monitoring and could improve glaucoma care.

Reference

Continuous 24-hour monitoring of intraocular pressure patterns with a contact lens sensor safety, tolerability, and reproducibility in patients with glaucoma.
Mansouri K, Meideiros F, Tafreshi A, Weinreb R.
ARCHIVES OPHTHALMOLOGY
2012130:1534-9.

Archives Ophthalmology

Lipid detection in the sub-RPE space using OCT
Reviewed by: Lorraine North
Apr/May 2013 (Vol 19 No 6)
 

The authors describe using spectral domain optical coherence tomography (SD-OCT) to image the sub-retinal epithelium (RPE) space in patients with neovascular age-related macular degeneration (AMD) with pigment epithelial detachments (PEDs). They describe the onion sign, which refers to layered hyper reflective bands in the sub-RPE space which they believe represents lipid trapped within fibrovascular tissue. This was a retrospective observational case review of 20 patients looking at clinical histories, imaging using SD-OCT, colour and red free photographs, near infrared reflectance, fundus autofluorescence and blue-light autofluorescence. All patients had neovascular age-related macular degeneration with type 1 (sub-RPE) neovascularisation. Twenty-two eyes of the 20 patients were identified as having layered sub-RPE hyper reflective bands, the onion sign. The length of the bands appeared to correlate with the size of the PED and the shape of the bands varied. The bands seen on OCT correlated with deep yellow-gray deposits on clinical examination and colour photographs. However, in several eyes they were able to document the development of the onion sign where prior colour photography had not. Although melanin, fibrin and collagen may be listed as possible explanations of this onion sign, the authors felt that this was not consistent in their findings. They hypothesised that the onion sign resulted from layers of deposited lipid within type 1 neovascular tissue. They propose that this is the first report of sub-RPE lipid detection by OCT examination.

Reference

Optical coherence tomographic imaging of sub-retinal pigment epithelium lipid.
Mukkamala SK, Costa RA, Fung A, et al.
ARCHIVES OPHTHALMOLOGY
2012;130:1547-53.

British Journal of Ophthalmology

Impact of changing oxygenation policies on ROP
Reviewed by: Jonathan Chan
Apr/May 2013 (Vol 19 No 6)
 

This observational study took place in a level three neonatal intensive care unit (NICU) in a government hospital, with an average of 6,500 births of year, in Cordoba, Argentina, between January 2003 and December 2006. The inclusion criteria for screening of retinopathy of prematurity (ROP) in this local programme includes patients with a birth weight (BW) of 1,500 grams or less and gestational age (GA) of 32 weeks or less and larger more mature infants who had an unstable clinical cause or who were exposed to known risk factors for ROP as well. There were three different time periods for such examination: period 1 – high target oxygen saturation levels (88-96%) and treatment at threshold ROP; period 2: low target oxygen saturation levels (83-93%) and treatment at threshold ROP; period 3: low target oxygen saturation and treatment at type 1 ROP. A total of 1,532 infants were examined at least once; 392 (25.6%) infants did not receive all the eye examinations required. One hundred and seventy-six (11.5%) were lost after discharge from the NICU and 216 (14.1%) only attended some examination as outpatients. Type 1 ROP was detected in 65/1532 (4.2%) infants overall, occurring more frequently in smaller babies (50/365, 13.7%), in more mature babies (15/1167, 1.3%; p<0.001.) In period 1, 6.9% of babies developed type-1 ROP, which declined to 3.6% in period 2 and 1.8% in period 3, representing a 75% reduction between periods 1 and 3. Only 0.6% (5/757) of the bigger babies developed type-1 ROP during periods 2 and 3, compared with 2.4% (10/410; P=0.02) in period 1 when high oxygen saturations were being used. The equivalent data for small babies was 10% (2/198) compared with 18% 30/167; P=0.04). The mean birth weight of the 65 babies developing type-1 ROP declined from 1,250 grams in period 1, to just over 1,000 grams in periods 2 and 3. The mean gestational age also declined from 30 weeks in period 1 to less than 30 weeks in periods 2 and 3. The mortality rate in period 1 was 130.3/1000 live births and 134.1/1000 for periods 2 and 3. A total of 54 of the 65 babies developing type-1 ROP were treated. The eleven babies not treated were examined in periods 1 and 2 and threshold disease was the indication for treatment. Almost half of all treatments were undertaken after the baby had been discharged (26/54, 48.1%). Bigger babies were more likely to be treated after discharge than smaller babies (83.3% versus 38.15; P=0.01). Six (11%) smaller babies had an unfavourable outcome. The authors conclude that there was a significant reduction in both the rate of type-1 ROP and of stage-3 and of plus disease over the four years of the study and a decline in the mean birth weight and gestational age of affected babies. The lowering of the target oxygen saturation was associated with a lower rate of severe ROP without increasing mortality and a change in the characteristics of the affected babies. A potential confounding factor is that the case mix of babies examined may have changed over time, but the mean birth weight and gestational age of babies examined in each of the time periods did not change significantly. In addition, in the study, over a quarter of all eligible infants did not undergo all the examinations required and almost half of all babies needing treatment were treated after discharge from the unit. The authors recommended that the screening criteria should maintain wider screening in order to identify all babies at risk of ROP needing treatment.

Reference

Impact of changing oxygenation policies on retinopathy of prematurity in a neonatal unit in Argentina.
Urrets-Zavalia JA, Crim N, Knoll EG, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96:1456-61.

Clinical and Experimental Ophthalmology

Chemotherapeutic reduction of retinoblastoma
Reviewed by: Kwesi Amissah-Arthur
Apr/May 2013 (Vol 19 No 6)
 

Globe salvage rates since the introduction of chemotherapeutic reduction of retinoblastoma has improved. However, there is minimal information about the long-term visual morbidity of these patients following chemo reduction. This retrospective study, by Narang et al. from the ocular oncology service of the Wills Eye Institute, of 140 eyes of 96 new retinoblastoma patients from 1995 to 2004, aims to determine the clinical features of long-term visual outcome after chemo reduction. All the participants had a minimum of four years follow-up. Their ages at presentation ranged from 0.25 months to 48 months. Demographics and baseline tumour characteristics, including number, size (tumour basal diameter and thickness), location, proximity of nearest tumour margin to optic disc and macula, location of main feeder vessel relative to macula, staging of retinoblastoma (International and Reese Ellsworth classifications) and retinoblastoma treatments, were recorded. All patients were given six cycles of chemo reduction with vincristine (1.5mg/m2 and 0.05mg/kg for children ≤36months of age with maximum dose of ≤2mg), etoposide (150mg/m2 and 5mg/kg for children ≤36 months of age) and carboplatin (560mg/m2 and 18.6mg/kg for children ≤36 months of age). Adjuvant therapy was given in the form of transpupillary thermotherapy (TTT) or cryotherapy after two to three cycles of chemo reduction when there was reduction in tumour height to ≤2mm and basal diameter of ≤4mm for tumours. Iodine125 plaque therapy and external beam radiotherapy were reserved for recurrent and large tumours. Ambulatory vision (≥6/60) was achieved in 100 of 140 (71%) eyes, and vision of ≥6/12 was seen in 52 eyes (37%). Extra-foveal tumour and greater number of tumours in the eye were the only predictors of visual acuity ≥20/40. The mean basal tumour diameter was 9.8mm in eyes with multiple tumours and 12.2mm in eyes with single tumours (P=0.03). There were no severe chemotherapy-related complications suffered by the participants. Narang et al. do not report how many children kept each level of vision. They also excluded from their analysis 32 eyes that subsequently were enucleated. As mentioned in the editorial of this paper, an estimate derived from such a per-protocol analysis represents the best-case scenario as compared with an intention-to-treat analysis. The authors in the discussion wisely caution that their unexpected finding that multiple retinoblastoma predicted a better visual outcome may be a chance finding. The authors also mention the need to perform foveal-sparing TTT to prevent any foveal damage. They attribute any foveal damage to the direct effect of the tumour itself. This study does a lot to encourage ophthalmologists to think about the effect that new therapies in managing retinoblastoma are having, not only in the short-term for globe salvage, but also in the longer-term for visual outcome.

Reference

Predictors of long-term visual outcome after chemo reduction for management of intraocular retinoblastoma.
Narang S, Mashayekhi A, Rudich D, Shields CL.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(7):736-42. 

Current Eye Research

Systemic vascular endothelial dysfunction in patients with branch retinal vein occlusion
Reviewed by: Khadijah Basheer
Apr/May 2013 (Vol 19 No 6)
 

This is a retrospective study comparing the systemic vascular endothelial function of patients with branch retinal vein occlusion (BRVO) to healthy controls and hypertensive patients (both of which had no ocular disease) to see if poor systemic endothelial function is a risk factor for BRVO. There are known common risk factors for retinal vein occlusion, namely: hypertension, diabetes, hypercholesterolaemia and renal dysfunction. However, the pathogenesis of retinal vein occlusion is still debated. Current hypotheses suggest that retinal vein occlusion occurs following compression of the vein at the arterio-venous crossing, degenerative changes in the vessel wall and abnormal haematological factors. Systemic vascular endothelial function can be measured by brachial artery ultrasound assessment of endothelium dependent flow mediated vasodilation (FMD). Previous studies have made associations between reduced FMD and both glaucoma and diabetic retinopathy but the relationship between systemic endothelial function and ocular circulation remains unclear. This study proposed that vascular endothelial dysfunction could also be associated with the pathogenesis of BRVO. A total of 47 patients were included, 27 of whom had BRVO, 10 with hypertension and no ocular or other systemic disease and 10 healthy volunteers. They were matched for age and gender. Following the FMD assessment it was found that the BRVO group had significantly decreased average FMD compared to both the healthy and hypertensive group. Multiple logistic regression analysis identified lower FMD as an independent risk factor for BRVO. This study suggests a statistically significant association between vascular endothelial dysfunction and BRVO but the size of the cohorts studied is a clear limitation. Clearly, further research is necessary to help to verify this association and its possible role in the pathogenesis of BRVO.

Reference

Impaired systemic vascular endothelial function in patients with branch retinal vein occlusion.
Tanano I, Nagaoka T, Sogawa K, et al.
CURRENT EYE RESEARCH
2013;38:114-8.

Experimental Eye Research

Differential gene variants in Chinese patients with retinal disease
Reviewed by: Graham Wallace
Apr/May 2013 (Vol 19 No 6)
 

Polypoidal choroidal vasculopathy (PCV) and neovascular age-related macular degeneration (nAMD) are leading causes of visual impairment in elderly Asian individuals. These conditions have a similar phenotype, although they can be separated by indocyanin green angiograph. Several gene variants have been identified in genome-wide association studies (GWAS) for AMD including the high-density lipoprotein (HDL) pathway. In this study on Han Chinese patients the impact of these variants on nAMD and PCV was analysed. The results showed that known AMD variants in CFH, ARMS2 and HTRA1 were also associated with PCV, as was one of the HDL variants in cholesteryl ester transfer protein (CETP), which was inversely correlated with serum HDL-c levels. Interestingly, none of the HDL variants were associated with AMD in this cohort, even accepting that these patients were susceptible to hypertension and coronary artery disease. This data strongly supports the requirement to validate GWAS data in different ethnic populations. Secondly, the authors state the need to treat PCV and nAMD separately particularly in Asian cohorts due to the higher proportion of PCV.

Reference

Different impact of high-density lipoprotein-related genetic variants on polypoidal choroidal vasculopathy and neovascular age-related macular degeneration in a Chinese Han population.
Zhang X, Li M, Wen F, et al.
EXPERIMENTAL EYE RESEARCH
2013:108;16-22.

Experimental Eye Research

IOP measurement in glaucoma
Reviewed by: Graham Wallace
Apr/May 2013 (Vol 19 No 6)
 

Glaucoma is a major cause of blindness, in which raised intraocular pressure (IOP) is a risk factor for onset and progression. However, many previous studies only measured IOP at wide intervals and the true variability associated with disease is not clear. In this study IOP was induced by laser treatment of the trabecular meshwork in rhesus macaque primates, and measured every one to three weeks by tonometry. The results showed that the rate of change of both mean position of disc, as identified by confocal scanning laser tomography, and retinal nerve fibre layer thickness from optical coherence tomography analysis were predicted by mean and maximum IOP. Normalised root mean squared residual IOP measurements provided the best correlation with other features; however, IOP variability itself was not an independent risk factor. Rather, normalisation allows the separation of IOP variability from chronic IOP levels.

Reference

Intraocular pressure magnitude and variability as predictors of rates of structural change in non-human primate experimental glaucoma.
Gardiner SK, Fortune B, Wang L, et al.
EXPERIMENTAL EYE RESEARCH
2012;103:1-8.

Experimental Eye Research

Lipoxin A4 inhibits action of PAF in corneal wounding
Reviewed by: Graham Wallace
 

Inflammation is a necessary feature of wound-healing in response to damage, but chronic inflammation in tissue such as the cornea leads to opacity, ulceration and tissue destruction. Corneal inflammation induces the release of arachadonic acid (AA) and biologically active lipid derivatives and platelet activating factor (PAF). Injury increases expression of PAF receptor that encourages the inflammatory reaction, via induction of metalloproteinases involved in tissue destruction. Lipoxin-A4 (LXA4), a derivative of AA, is an anti-inflammatory molecule that stimulates epithelial and endothelial cell proliferation. To test the interaction of these molecules corneal injury in mice was induced by removal of the epithelium and anterior stroma up to the limbal border in one eye. Following injury, mice were either treated with PAF, LAU-0901, a PAF-antagonist and PAF, PAF and LXA4 with a fourth group receiving vehicle only. At various time points mice were sacrificed and the eyes prepared for histology. PAF alone inhibited epithelial wound healing, a response that was blocked by LAU-0901. LXA4 also inhibited the effects of PAF and led to increased wound healing, the balance between these two inflammation-induced mediators suggests that increasing LXA4 levels in wounded corneas will have a beneficial effect.

Reference

Lipoxin A4 inhibits platelet-activating factor inflammatory response and stimulates corneal wound healing of injuries that compromise the stroma.
Kakazu A, He J, Kenchegowda S, Bazan HE.
EXPERIMENTAL EYE RESEARCH
2012;103:9-16.

Eye

Deep sclerectomy in paediatric glaucoma surgery
Reviewed by: John Brookes
Apr/May 2013 (Vol 19 No 6)
 

Paediatric glaucoma is generally regarded as a surgical disease and a wide variety of procedures have been used. Generally, angle surgery is the preferred initial surgical treatment in primary congenital glaucoma (PCG) in the United Kingdom but in many countries, where the disease tends to present later and more advanced, a combined trabeculectomy-trabeculotomy with mitomycin C (CTTM) is employed, often with good reported outcomes. Often, in children with PCG, the distorted limbal anatomy makes identifying Schlemm’s canal difficult, during the trabeculotomy part of this procedure. This paper from Egypt is a prospective, randomised case series looking at the additive value of deep sclerectomy to the procedure of CTTM, in assisting identification of Schlemm’s canal. The study involved 20 eyes of 20 children presenting with PCG and was randomised during surgery with the toss of a coin, after the scleral flap had been fashioned. The author argues that at this point, no difference in scleral flap thickness would be made than if the randomisation had happened preoperatively. The mean age of the children was 4.7 months in the CTTM group and 7.0 months in the CTTM with deep sclerectomy (CTTM-DS) group. The mean intraocular pressure (IOP) at 12 months was 4.9mmHg in the CTTM group and 5.6mmHg in the CTTM-DS group (measured with inhalational anaesthesia). The IOP was lower in the CTTM-DS group at two months postoperatively but was not significant, although interestingly, the duration of the surgery was less in the combined group with deep sclerectomy. All cases had successful IOP control at 12 months, with no significant or vision-threatening complications. The author suggests that combining this procedure with the standard CTTM allows better and more accurate localisation of Schlemm’s canal for the trabeculotomy part of the procedure. However, this study is relatively few in number to pick up any great difference in success between the two procedures. There was also an apparent difference in ages between the two groups, which although does not sound great, can make a significant difference to the success of paediatric glaucoma surgery. The main conclusion from the study is that adding a deep sclerectomy to the CTTM facilitates finding Schlemm’s canal, shortens the duration of the procedure and does not add any additional complications.

Reference

Deep sclerectomy in pediatric glaucoma filtering surgery.
Bayoumi NHL.
EYE
2012;26:1548-53.

Eye

Post-intravitreal anti-VEGF endophthalmitis in the UK
Reviewed by: John Brookes
Apr/May 2013 (Vol 19 No 6)
 

Age-related macular degeneration (AMD) can cause severe visual loss and is the commonest cause of blind registration in patients aged over 50 years in the developed world. ‘Wet’, or exudative, AMD accounts for 10% of cases and estimates have shown that there are 26,000 patients eligible for anti-vascular endothelial growth factor (anti-VEGF) treatments in the UK each year. Intra-vitreal injections, however, are not without risks, including endophthalmitis. This paper describes the incidence, features, management and risk factors of post-intravitreal anti-VEGF endophthalmitis (PIAE). This was a prospective, observational case control study. Forty-seven cases were reported through the British Ophthalmological Surveillance Unit (BOSU) from January 2009 to March 2010. The estimated incidence of PIAE was 0.025%, and culture positive PIAE was 0.015%. The mean number of intravitreal injections before PIAE was five and mean days to presentation was five days (range 1-39 days). The majority of causative organisms were Gram positive (92.8%). Significant risk factors were failure to administer topical antibiotics immediately after the injection, blepharitis, subconjunctival anaesthesia and patient squeezing during the injection. Forty-six of the cases followed intravitreal ranibizumab and one case followed bevacizumab. The most common presenting symptom was reduction in vision (96%). Pain and photophobia was present in 73%. The most common signs were vitritis (91%), hyperaemia (76%) and hypopyon (76%). All patients underwent intravitreal injections of antibiotic, most commonly vancomycin and amikacin. Forty-four patients underwent vitreous biopsy with a positive yield in 59.1%. Aqueous biopsy only yielded a positive yield of 15.8%. The majority of cases (63.6%) had worse vision after six months of follow-up when compared with acuity pre-PIAE. The authors suggest that measures to minimise the risk of PIAE include treatment of blepharitis before injection, avoidance of subconjunctival anaesthesia, topical antibiotic administration immediately after injection with consideration to administering topical antibiotics before injection.

Reference

Post-intravitreal anti-VEGF endophthalmitis in the United Kingdom: incidence, features, risk factors and outcomes.
Lyall DAM, Tey A, Foot B, et al.
EYE
2012;26:1517-26.

Investigative Ophthalmology and Visual Science

Induced monocular blur vs. anisometropic amblyopia
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The study investigated whether changes in programming and executing saccades and reaching movements seen in anisometropic amblyopia are due to a reduction in visual acuity alone by introducing artificial blur in one eye in visually normal subjects. Blur was induced by contact lenses (0.75 to 2D range). The results showed no effect to saccades and reaching performance in visually normal subjects with induced monocular blur. Thus, loss of visual acuity alone cannot explain changes in anisometropic amblyopia.

Reference

Effects of induced monocular blur versus anisometropic amblyopia on saccades, reaching and eye-hand coordination.
Niechwiej-Szwedo E, Kennedy SA, Colpa L, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(8):4354-62.

Investigative Ophthalmology and Visual Science

Anisometropia in children
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The study investigates how anisometropia develops during childhood and changes over a wide age range from infancy to 15 years, how anisometropia in teenagers relates to refractive characteristics in infancy and preschoolers, and how anisometropia in early childhood relates to astigmatism in infancy and asymmetry in refraction at 12-15 years. Refractive data was provided by 1,120 children at six months, 395 children provided data at five years and 312 children at 12-15 years. A clear myopic shift was seen with age. The prevalence of anisometropia of 1-2% was recorded at six months and five years, with 5.8% at 15 years. Anisometropia for both myopia and hyperopia was recorded. A cut off of 1D interocular difference was considered. Infants with significant astigmatism had an increased risk of anisometropia.

Reference

Anisometropia in children from infancy to 15 years.
Deng L, Gwiazda JE.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(7):3782-7.

Investigative Ophthalmology and Visual Science

Central visual field loss and navigating obstacles
Reviewed by: Fiona Rowe
Arp/May 2013 (Vol 19 No 6)
 

Ten patients with central visual field loss were tasked with completing two tasks of walking up to and stepping over an obstacle during ongoing gait plus walking across the lab with no obstacle present. The results were compared to 12 participants of similar age with normal vision. Detailed assessment of kinematics of obstacle crossing and level walking provided results that showed that patients with field loss adopted a cautious crossing strategy to reduce the risk on contacting the obstacle and tripping or falling. There was no difference for the walking only task. Patients lifted their lead and trail foot significantly higher, reduced lead horizontal foot velocity for low obstacles and increased head flexion to look down at the more immediate areas of the floor and obstacle.

Reference

Patients with central visual field loss adopt a cautious gait strategy during tasks that present a high risk of falling.
Timmis MA, Pardhan S.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(7):4120-9.

Investigative Ophthalmology and Visual Science

Low vision and quality of life
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The aim was to assess as many factors as possible in a large unselected sample of low vision patients who attended a hospital low vision clinic delivering typical low vision care, in order to identify those factors that predict quality of life in people with low vision. Three questionnaires were used: LVQoL-25, Adaptation to age-related vision loss-12, Keele participation restriction (KAP). The study was completed by 488 subjects. The results show that vision-related quality of life, determined by three different patient reported outcomes, is strongly dependent on factors unrelated to the use of low vision aids, in particular the mental and physical components of general health. The authors propose that researchers investigate the effectiveness of any intervention should take care when choosing questionnaires to measure quality of life for people with low vision, as quality of life will be affected by other issues in patients lives in addition to their poor sight.

Reference

The impact of visual and non visual factors on quality of life and adaptation in adults with visual impairment.
Trillo AH, Dickinson CM.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(7):4234-41.

Investigative Ophthalmology and Visual Science

Myopia and outdoor exposure
Reviewed by: FIona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The aim of this study was to determine the relationship between myopic refractive error and time spent outdoors using both subjective and objective methods of measuring outdoor exposure. Six hundred and thirty-six subjects participated and the results suggested a protective association between areas of conjunctival UV auto fluorescence (UVAF) and prevalent myopia. UVAF is unlikely to be involved in the causal pathway of myopia but represents a valid biomarker of sub-acute exposure to light outdoors. The median total UVAF was lower in myopic subjects than non-myopes.

Reference

The association between time spent outdoors and myopia using a novel biomarker of outdoor light exposure.
Sherwin JC, Hewitt AW, Coroneo MT, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(8):4363-70.

Investigative Ophthalmology and Visual Science

Rating scale design in the measurement of PROs
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The authors used their vision-related activity limitation (VRAL) item bank data to explore actual effect of rating scales on item calibrations. They investigated the impact of rating scales on the overall difference in VRAL scores measured by different patient-reported outcomes (PROs). Ten PROs randomly selected from 16 were completed by 614 patients. A total of 226 items were included. The data was pooled together for Rasch analysis to calibrate the 226 items. The results show that differences in rating scale formats have a significant effect on item calibration beyond item content. Items with the same content varied in their calibration by as much as two logits. Reading had the most variance followed by watching TV.

Reference

The importance of rating scale design in the measurement of patient-reported outcomes using questionnaires or item banks.
Khadka J, McAlinder C, Gothwal VK, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(7):4042-54.

Investigative Ophthalmology and Visual Science

The infant aphakia treatment study
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The purpose is to examine the inter-relationships between treatment, adherence to patching within the first six months after surgery and grating acuity measured at 12 months of age. One hundred and eight children were assessed: 55 with intraocular lens (IOL) and 53 aphakic. Carers reported patching for 84% of the prescribed time. Adherence to occlusion treatment in the first six months following cataract extraction was found to be associated with visual acuity in infants treated between one and seven months of age for unilateral cataract surgery and particularly pseudophakic children. Adherence to occlusion did not differ for treatment.

Reference

Adherence to occlusion therapy in the first 6 months of follow-up and visual acuity among participants in the infant aphakia treatment study (IATS).
Drews-Botsch CD, Celano M, Kruger S, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(7):3368-75.

Journal of Glaucoma

Nasal Spray and IOP
Reviewed by: Lorraine North
Apr/May 2013 (Vol 19 No 6)
 

The authors describe a prospective randomised double masked placebo controlled trial. The aim was to determine if intranasal steroids affect intraocular pressure (IOP). Patients aged between 18-85 years with controlled primary open angle glaucoma (POAG) or ocular hypertension (OHT) were recruited. The patients were included if they had no previous steroid use within six weeks and had target IOP with stable visual fields. Patients were then randomised to beclomethasone nasal spray versus saline placebo nasal spray. They were instructed to use two sprays in each nostril twice daily. Nineteen patients were recruited, nine in the steroid arm and 10 in the placebo arm. The main outcome measure was the IOP. This was measured using Goldmann applanation tonometry taking two measurements. Visual acuity, anterior segment changes and a record of any side-effects and compliance was also recorded. There was no statistically significant difference between the two groups at each study visit. Previous literature evaluating the effect of nasal steroids in glaucoma is sparse. Systemic, periocular, and topical chronic ophthalmic corticosteroids have been associated with ocular side-effects such as glaucoma for a long time. However, in this trial the steroid group did not have an elevated mean IOP compared with the placebo group for all visits up to six weeks, which they feel shows that it is safe to use beclomethasone nasal spray in well controlled OHT and POAG. The study, however, only had a small sample size of nineteen and a longer follow-up duration could be explored.

Reference

Effect of beclomethasone nasal spray in intraocular pressure in ocular hypertension or controlled glaucoma.
Yuen D, Buys YM, Jin Y, et al.
JOURNAL OF GLAUCOMA
2013;22:84-7.

Journal of Glaucoma

VFI after cataract extraction
Reviewed by: Lorraine North
Apr/May 2013 (Vol 19 No 6)
 

The authors describe a retrospective study of 53 patients with glaucoma and cataracts to evaluate the effect cataract has on the visual field index (VFI). They also assessed the type of cataract to determine any effect. All patients had visual fields within a period of 15 months before and after surgery. Surgery was either cataract surgery alone or combined with trabeculectomy. Eighty-three eyes of 69 patients were examined, of these 53 eyes of 53 patients were included. The study demonstrates that the mean deviation (MD) and pattern standard deviation (PSD) were significantly affected, whereas VFI was not affected by cataract. The differences in global indices were also shown to be effected by the type of cataract. Those with nuclear sclerotic and posterior subcapsular cataracts showed an improved MD after cataract surgery, whereas the PSD significantly deteriorated after surgery in nuclear sclerotic but remained stable in posterior subcapsular. The VFI remained unchanged in both types of cataract after surgery. Although this study supports previous work they also describe the limitations of the study as only one visual field test was considered before and after cataract extraction, other studies have considered two or more. The authors conclude, however, that as VFI was not affected by cataract it may be a more robust measure of visual field damage when evaluating progression in glaucoma patients with cataract rather than looking at MD and PSD.

Reference

Effect of cataract extraction on visual field index in glaucoma.
Rao HL, Jonnadula GB, Adepalli UK, et al.
JOURNAL OF GLAUCOMA
2013;22:164-8.

Journal of Pediatric Ophthalmology and Strabismus

Acute IV palsy
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

This retrospective review included 32 cases presenting with acute vertical diplopia due to fourth nerve paresis with data from orthoptic assessment at baseline, three and 12 month follow-up. Fifty-six percent were microvascular in aetiology, 19% decompensated plus closed head injury, migraine, Herpes Zoster virus and unknown cause. Fifty-nine percent were given prisms and two patients had occlusion to alleviate diplopia. The results support that most acute fourth nerve pareses are benign and resolve spontaneously. Symptoms in 72% resolved between two weeks and 10 months post onset. For microvascular cases, 89% made a spontaneous recovery – the remaining patients in this group did not attend follow-up. Spontaneous recovery was seen for other causes except those who had decompensated and who required active intervention with pris