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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 prisms or surgery.

Reference

Clinical course and characteristics of acute presentation of fourth nerve paresis.
Khaier A, Dawson E, Lee J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY & STRABISMUS
2012;49:366-9.

Journal of Pediatric Ophthalmology and Strabismus

Glaucoma surgery
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The authors compared the effectiveness of trabeculectomy versus combined trabeculotomy-trabeculectomy using adjunctive mitomycin C in both groups in patients with paediatric glaucoma. This retrospective study included 40 eyes of 33 patients with a mean follow-up of 38.3 months. The results showed similar IOP lowering efficacy for both procedures with significantly higher surgical success rates for the combined approach. The majority of cases had aphakic-pseudophakic glaucoma or secondary developmental glaucoma with anterior chamber anomalies. Both groups had complications, the majority of which were controlled with minor procedures.

Reference

Trabeculectomy versus combined trabeculotomy-trabeculectomy in pediatric glaucoma.
Lawrence SD, Netland PA.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY & STRABISMUS
2012;49:359-65.

Journal of Refractive Surgery

Piggyback IOL to correct refractive error following cataract surgery
Reviewed by: Amit Patel
Apr/May 2013 (Vol 19 No 6)
 

The authors report outcomes of a sulcus piggyback lens (Sulcoflex, Rayner, UK) in 15 pseudophakic eyes (of 13 patients). Three eyes were implanted with the aspheric lens (653L) and 13 eyes with the toric version (653T). The multifocal lens was not used in this series. All surgery was performed a minimum of three months following the initial surgery and following two stable refractions. Mean preoperative uncorrected distance visual acuity (UDVA) was 20/55 and all patients achieved >20/32 UDVA three months postoperatively. Preoperative mean spherical and astigmatic errors were 1.07±0.83 diopters (D) and -1.45±0.98 D, respectively. Postoperative mean sphere and astigmatism at three months were -0.25±0.38 D and -0.50±0.57 D, respectively. All patients experienced an improvement in UDVA and no loss of uncorrected or corrected acuity was noted. All patients were within 1.00 D of attempted correction, with 93% within 0.50 D. No intraoperative complication occurred. Postoperatively, one eye had raised intraocular pressure and three eyes had anterior chamber flare. No lens tilt or rotation was observed. The authors address the limitations of their study (small sample size, retrospective, short follow-up and subjective assessment of lens alignment/stability). They conclude that the lens offers an effective and predictable option for enhancing postoperative refractive results and reducing spectacle dependence for distance after surgery. Although none of the 15 eyes had previously undergone laser refractive surgery, the authors suggest that the Sulcoflex lens may be used to correct post-cataract surgery refractive errors in this group of patients.

Reference

Correction of undesirable pseudophakic refractive error with the Sulcoflex intraocular lens.
Falzon K, Stewart OG.
JOURNAL OF REFRACTIVE SURGERY
2012;28(9):614-9.

Journal of Refractive Surgery

Scheimpflug assessment of corneal changes after collagen cross-linking
Reviewed by: Amit Patel
Apr/May 2013 (Vol 19 No 6)
 

This study compared 25 eyes with progressive keratoconus treated with collagen cross-linking (CXL group) with 15 fellow eyes that served as control (Control group). Progression was classified as >1.00 dioptres (D) increase in keratometry over six months and subjective loss of corrected distance visual acuity (CDVA) by >2 lines in one year. Uncorrected and corrected distance visual acuity (UDVA, CDVA), thinnest corneal thickness (ThCT), posterior elevation and keratometry values (K1, K2) were determined by schiemplfug imaging using the Pentacam (Oculus Optikgerate, GmbH) before and one year after CXL. At one year, both UDVA and CDVA improved in the CXL group (p<0.001 and p=0.019 respectively). A significant decrease in ThCT, posterior elevation, K1 and K2 values was also noted in this group. Receiver operator characteristic curve showed posterior elevation as the most characteristic parameter of flattening after CXL, followed by K2 and K1. Also, the general estimating equation model showed that higher initial ThCT was inversely related to posterior elevation change. Whilst previous studies have demonstrated the flattening effect following CXL, this study shows flattening of both anterior and posterior elevation, with the latter being more sensitive. It also shows that the CXL effect is augmented in eyes with thinner corneas and the authors suggest considering this as a therapeutic option in advanced keratoconus and in planning of topography guided laser surgery and CXL.

Reference

Corneal changes in progressive keratoconus after cross-linking assessed by Scheimpflug camera.
Kránitz K, Kovács I, Miháltz K, et al.
JOURNAL OF REFRACTIVE SURGERY
2012;28(9):645-9.

Neuro-ophthalmology

Acute onset of Charles Bonnet Syndrome after eye patching
Reviewed by: Claire Howard
Apr/May 2013 (Vol 19 No 6)
 

The article describes a case report of one patient with Charles Bonnet Syndrome (CBS) secondary to eye patching with unusually acute onset. The 48-year-old woman presented with visual hallucinations that started less than 30 minutes after patching her left eye. The eye patch was removed after two days but the complex hallucinations persisted for two more days following eye patch removal. She underwent extensive psychiatric and medical examinations and no other explanation was found for her visual hallucinations. Although only one case was reported the authors suggest that ophthalmic clinicians should be aware of the potential for development of CBS following eye patch wear.

Reference

Acute reversible Charles Bonnet Syndrome following eye patch placement.
Nan L, Yanbin H, Jingping Z.
NEURO-OPHTHALMOLOGY
2013;37:35-7.

Ophthalmic Genetics

Genetic heterogeneity in anophthalmia
Reviewed by: Nana Theodorou
Apr/May 2013 (Vol 19 No 6)
 

Failure during the developmental embryonic stages of the eye can lead to a spectrum of disorders such as microphthalmia, anophthalmia and coloboma. The prevalence is low but such cases represent important causes of paediatric blindness. The authors describe anophthalmia as a heterogeneous developmental disorder with a diverse aetiology such as chromosomal and monogenic aberrations, as well as environmental causes. They used DNA samples from six individuals, two anophthalmic, genotyped with an array featuring approximately 620,000 single nucleotide polymorphisms in order to identify homozygous or copy number variant regions. Direct sequencing was employed to screen for candidate genes located in regions of identity by descent defined by homozygosity mapping. Some two thirds of MAC cases arise sporadically, while the remainder show evidence of familial recurrence. The phenotype may be restricted to ocular mal-development, or alternatively be syndromic with systemic malformations that can include: cardiac defects, facial dysmorphism, microcephaly and hydrocephaly. The authors reported that the key finding of their study was identification of five shared autozygous blocks that do not correspond with known MAC loci. Although constrained by the pedigree’s size, the homozygosity mapping approach employed in this study extends the locus heterogeneity of anophthalmia.

Reference

Homozygosity mapping in an anophthalmic pedigree provides evidence of additional genetic heterogeneity.
Khorshidi A, Russell L, Bamforth S, et al.
OPHTHALMIC GENETICS
2012;33(4):208-20.

Ophthalmologica

Preoperative bevacizumab in neovascular glaucoma drainage surgery
Reviewed by: Ticiana Criddle
Apr/May 2013 (Vol 19 No 6)
 

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 glaucoma 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
2013;229:94-100.

Ophthalmology

Intravitreal aflibercept (VEGF Trap-Eye) in wet AMD
Reviewed by: Brian Ang
Apr/May 2013 (Vol 19 No 6)
 

The authors report on the results of two similar phase-3 double-masked, multi-centre, controlled, randomised trials assessing the efficacy of aflibercept (VEGF Trap-Eye) in the treatment of wet age-related macular degeneration (AMD). Aflibercept is a receptor fusion protein that has previously been shown to have greater binding affinity to VEGF compared to bevacizumab or ranibizumab. Patients with wet AMD were randomised in a 1:1:1:1 ratio (0.5mg aflibercept four-weekly; 2mg aflibercept four-weekly; 2mg aflibercept eight-weekly; and 0.5mg ranibizumab four-weekly), and examined every four weeks until week 52. In the eight-weekly regimen, alibercept is given once monthly for three months followed by eight-weekly injections. Intravitreal aflibercept injections were safe, with an incidence of ocular or systemic events of less than one per 1000 injections. This was less than the incidence for ranibizumab, although the difference was not statistically significant. The group with the highest exposure to aflibercept had the lowest rates of adverse events. More importantly, in all the aflibercept treatment groups, the visual acuity outcomes demonstrated non inferiority to ranibizumab, with vision within 0.5 letters of the reference ranibizumab change. These are exciting findings because aflibercept offers the potential of reducing injections to eight-weekly, which will significantly reduce the burden of monthly monitoring and injecting.

Reference

Intravitreal aflibercept (VEGF Trap-Eye) in wet age-related macular degeneration.
Heier JS, Brown DM, Chong V, et al.
OPHTHALMOLOGY
2012;119:2537-48.

Ophthalmology

Phacoemulsification vs. laser peripheral iridotomy
Reviewed by: Brian Ang
Apr/May 2013 (Vol 19 No 6)
 

The authors report on a prospective, randomised controlled trial comparing long-term intraocular pressure (IOP) control at two years following treatment with laser peripheral iridotomy (PI) or phacoemulsification cataract surgery acute primary angle closure (APAC). Only patients whose IOP had reduced to less than 30mmHg within 24 hours after medical treatment, and whose vision was worse than 6/15 were eligible for study recruitment. Laser PI was usually performed within 72 hours, while phacoemulsification was usually performed within seven days of the APAC episode. Surgeons were allowed to inject viscoelastic 360 degrees around the angle during phacoemulsification. Failure of IOP control was defined as either IOP between 22 and 24mmHg on two occasions or IOP greater than 24mmHg on one occasion from week three onwards after the intervention. A total of 37 patients were recruited, with 18 randomised to laser PI and 19 randomised to phacoemulsification. Interestingly, at six months, there was no difference in visual acuity between both groups, suggesting that cataract does not have to be visually significant before it can cause acute angle closure. There was also no significant difference in corneal endothelial cell count at six months. In terms of the study’s definition of failure of IOP control, phacoemulsification had a lower rate of IOP failure at two years in comparison to laser PI. The results of the study are to be expected because laser PI only removes the pupil block component of angle closure. In contrast, phacoemulsification serves to remove not only the lens-induced, but often also the pupil block component of angle closure.

Reference

Initial management of acute primary angle closure; a randomized trial comparing phacoemulsification with laser peripheral iridotomy.
Husain R, Gazzard G, Aung T, et al.
OPHTHALMOLOGY
2012;119:2274-81.

Orbit

Comparison of MRI with traditional histopathology
Reviewed by: Konal Saha
Apr/May 2013 (Vol 19 No 6)
 

The authors describe the use of high resolution magnetic resonance imaging (MRI) to examine a globe affected by choroidal melanoma ex vivo, after enucleation. They correlate the MR findings with histopathological examination. Correlation between the two examination methods was strong and impressively detailed MR images are presented. The authors conclude that MR microscopy could be a useful diagnostic assessment tool for intraocular malignant masses. Current 7.1T MR scanners have small bores, hence, the examination must be carried out ex vivo.

Reference

MR microscopy of the human eye at 7.1T and correlation with histopathology – proof of principle.
Krueger P-C, Stachs O, Hadlich S, et al.
ORBIT
2012;31(6):390-3.

Orbit

Immunohistochemical markers in orbital cavernous haemangioma
Reviewed by: Konal Saha
Apr/May 2013 (Vol 19 No 6)
 

Results are presented for an immunohistochemical study on 11 cavernous haemangioma specimens to gain an insight into their histogenesis and growth mechanism. Ninety-one percent of cases were positive for proliferating cell nuclear antigen, 73% of cases were positive for Bcl-2 and all cases were negative for Mib-1. The authors conclude that this immunohistochemical profile indicates the low proliferative potential of the majority of these lesions.

Reference

Orbital cavernous haemangiomas: immunohistochemical study of proliferative capacity, vascular differentiation and hormonal receptor status.
Gupta A, Prabhakaran VC, Dodd T, et al.
ORBIT
2012;31(6):386-9.

Orbit

Post botulinum toxin injection facial squeezing of facial dystonia
Reviewed by: Konal Saha
Apr/May 2013 (Vol 19 No 6)
 

The authors present a prospective, consecutive, double crossover interventional study to determine if post botulinum toxin injections to the periocular region are more efficacious if the patient carries out voluntary muscle squeezing following their injections. Twenty-six patients with essential blepharospasm, hemifacial spasm or aberrant facial nerve regeneration were recruited. No statistically significant difference was found between the ‘squeezing’ and ‘non-squeezing’ groups, however, there was a non-statistically significant increase in efficacy in the ‘squeezing’ group. The authors suggest a clinically and statistically significant result may be obtained in a more tightly defined subset of patients such as those becoming resistant to treatment.

Reference

A comparison of facial muscle squeezing versus non-facial muscle squeezing on the efficacy of botulinum toxin-A injections for the treatment of facial dystonia.
O’Reilly P, Ross J, Norris J, Malhotra R.
ORBIT
2012;31(6):400-3.

Strabismus

Central vision crowding ratios
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The goal of this study was to measure crowding ratios in 75 normally sighted and 58 visually impaired children with a variety of visual charts. The authors found higher crowding ratios for visually impaired children than normally sighted children. They found a partial age-related reduction of crowding effects. Crowding ratios were higher for visually impaired patients with nystagmus than those without nystagmus. The results showed that inter symbol spacing (ISS) and test design (fixed or proportional) have a substantial influence on crowding ratios with ratios higher for ISS charts.

Reference

Crowding in central vision in normally sighted and visually impaired children aged 4 to 8 years: the influence of age and test design.
Huurneman B, Boonstra FN, Cillessen AHN, et al.
STRABISMUS
2012;20:55-62.

Strabismus

Diagnosing cerebral visual impairment in children with good visual acuity
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The purpose was to identify elements that, in the general ophthalmic clinic, could facilitate the diagnosis of cortical visual impairment (CVI) in children with good visual acuity and thus aid in deciding which children should be referred to specialised institutes for multidisciplinary assessment. This retrospective study investigated the clinical characteristics of 30 children with good visual acuity and CVI and compared them to those of 23 children with diagnoses other than CVI. The results show that an uneventful medical history makes CVI very unlikely. Homonymous visual field defects and partial optic atrophy are exclusively seen in CVI patients. Lower visual field loss is common in PVL. Crowding ratio >2 is common in CVI. The authors conclude that CVI remains primarily a clinical diagnosis heavily based on the presence of known causes of CVI in the medical history. Crowding ratio of >2 lines may be an indication of dorsal stream dysfunction. CVI questionnaires may be useful for identifying various symptoms of CVI but should not be used as a screening tool because of false positives.

Reference

Diagnosing cerebral visual impairment in children with good visual acuity.
Van Genderen M, Dekker M, Pilou F, Bols I.
STRABISMUS
2012;20:78-83.

Strabismus

Findings in Down syndrome for a Slovenian population
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

A retrospective study was conducted to document ocular findings and systemic disease in Down syndrome in a Slovenian population. Sixty-five children born between 1995 and 2009 were assessed from 2008 to 2010. Thirty-seven had trisomy 21, 26 had translocation and four had mosaicism. The most common systemic disease was heart defects followed by gastrointestinal, hypothyroidism, hypotony, hearing loss, cerebral paroxysms, equinovarus and leukaemia. Ocular findings included refractive error, strabismus, nystagmus, epiphora, lens opacities and retinal abnormalities. There was an incidence of one in 1,377. Eighteen percent had no systemic disease. The author concludes that co-morbidities are common and can complicate diagnosis, development and treatment.

Reference

Ocular abnormalities and systemic disease in Down syndrome.
Kranjc BS.
STRABISMUS
2012;20:74-7.

Strabismus

Inferior rectus rupture
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

A case of unilateral isolated traumatic inferior rectus rupture following assault is presented. At surgery, the insertion of the muscle to the globe was intact but the muscle belly was completely ruptured across its width approximately 12mm posterior to the insertion. The proximal end could not be located and the remaining nonviable stump was abscised. Following subsequent transposition surgery (Hummelscheim of medial and lateral rectus muscles) the patient regained a good field of binocular single vision and a good functional outcome.

Reference

The management of traumatic isolated inferior rectus rupture.
Batra R, Gao A, Shun-Shin GA.
STRABISMUS
2012;20:105-8.

Strabismus

Normal crowding ratios
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The purpose was to determine the normal range of the crowding ratio at distance and near in normally sighted primary school children of different age groups. Sixty-two children aged 4 to 12 years were tested with Lea symbol optotypes. Crowding ratio remained relatively constant across the different age groups. They found the ratio at reading distance was better than that at three metres. The mean crowding ratio values at distance was 1.40 for four to six year olds and 1.31 for six to 12 years. For near the means were 1.01 for both age groups. The authors conclude that crowding ratio of >2 is likely to be abnormal from age six upwards. Thus a difference of more than two lines in linear and single optotype acuity should be reason for further investigation.

Reference

Crowding ratio in young normally sighted children.
Dekker MJ, Pilou F, Bijveld MMC, et al.
STRABISMUS
2012;20:49-54.

Strabismus

Surgery for Duane’s syndrome
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

The authors describe the outcomes of a relatively large series (10 patients) of exo-Duane with up / down shoots after combined Y split and recession of the misinnervated lateral rectus muscle. A significant improvement was seen in head posture, primary deviation and down shoots. There was a trend towards improvement of up shoots. Three patients required additional procedures.

Reference

Isolated Y-splitting and recession of the lateral rectus muscle in patients with exo-Duane syndrome.
Velez FG, Velez G, Hendler K, Pineles SL.
STRABISMUS
2012;20:109-14.

Strabismus

Surgery for high AC/A ratio esotropia
Reviewed by: Fiona Rowe
Apr/May 2013 (Vol 19 No 6)
 

This study reports the long-term results of the pulley posterior fixation procedure for 21 consecutive patients with esotropia associated with increased AC/A ratio. The mean preoperative angle was 19.6±10.5 for distance and 36.9±18.9 for near. Eighty-five percent required glasses preoperatively (seven with bifocals). The mean medial rectus recession was 4.4mm±0.9. Late postoperative mean angle was 0.1±5.8 for distance and 1.0±6.2 for near. Seventy-one percent required glasses postoperatively but no bifocals. The authors report a high long-term effectiveness of the procedure.

Reference

Long term outcome of medial rectus recession and pulley posterior fixation in esotropia with high AC/A ratio.
Walulembo G, Demer JL.
STRABISMUS
2012;20:115-20.

Acta Ophthalmologica

Long-term visual function in preterm children
Reviewed by: Nana Theodorou
Feb/Mar 2013 (Vol 19 No 5)
 

In the last 15 years neonatal care has improved significantly and extremely premature infants survive. All children with a gestational age of 22-27 weeks were invited to an eye examination to assess visual acuity, refractive error, binocular vision, accommodation and fundus. Thirty-seven out of 52 eligible children participated and underwent an eye examination. The mean age was 6.3 years. Forty-six percent of the children had reduced vision but none >0.3. Distance vision was better in children without retinopathy of prematurity (ROP). Contrast sensitivity was within normal levels in 96% of participants. Ninety percent of participants were emetropic or slightly hypermetropic and 10% had manifest strabismus. Six patients had temporal optic disc pallor. Intelligence quotient (IQ) was also tested and was associated with best visual acuity. This study showed a favourable long-term visual prognosis for very premature babies.

Reference

Visual function in 6 to 7-year old children born extremely preterm: a population based study. 
Haugen OH, Nepstad L, Arne Standal O, et al.
ACTA OPHTHALMOLOGICA
2012;90:422-7.

Visual function in 6 to 7-year old children born extremely preterm: a population based study. 
Haugen OH, Nepstad L, Arne Standal O, et al.
ACTA OPHTHALMOLOGICA
2012;90:422-

Acta Ophthalmologica

Virtual reality cataract surgery training
Reviewed by: Nana Theodorou
Feb/Mar 2013 (Vol 19 No 5)
 

Cataract surgery is very common in ophthalmic practice. New learning techniques include virtual reality eye surgery simulators. This study investigated 35 medical students undertaking their ophthalmology training. All participants underwent simulator training using the EYESi surgical simulator. They were randomised into two groups either the virtual reality (VR) capsulorhexis or cataract navigation modules and they all had to complete ten iterations for each module. Both groups showed an improvement in performance over the 10 iterations. For the capsulorhexis the improvement was not statistically significant as it was for the cataract navigation training. The 10 iterations were not sufficient for capsulorhexis and there was no skills transfer between modules. There is scope to use these new training methods alongside clinical practice. Further studies are required to investigate the validity of simulators in cataract training.

Reference

Virtual reality cataract surgery training: learning curves and concurrent validity.
Selvander M, Asman P.
ACTA OPHTHALMOLOGICA
2012;90:412-7.

Virtual reality cataract surgery training: learning curves and concurrent validity.
Selvander M, Asman P.
ACTA OPHTHALMOLOGICA
2012;90:412-7

Archives Ophthalmology

Eyebrow tissue expansion
Reviewed by: Lorraine North
Feb/Mar 2013 (Vol 19 No 5)
 

This is a retrospective study of 75 patients to show that standardised photographic evidence can be used to identify and characterise the extent of eyebrow tissue involvement in patients referred with thyroid-associated orbitopathy (TAO). The authors report that by using photographic evidence and a grading system they are able to show the changes in eyebrow contour which would be useful when monitoring these patients and possibly to assess whether eyebrow involvement correlates with disease activity, fibrosis (diplopia) or disease severity. The standardised photographs may also prove useful in maintaining consistency among clinicians evaluating patients with eyebrow involvement and aid future management of these patients.

Reference

Eyebrow tissue expansion – an underappreciated entity in thyroid-associated orbitopathy.
Savar LM, Menghani RM, Chong KK, et al.
ARCHIVES OPHTHALMOLOGY
2012;130:1566-9.

Eyebrow tissue expansion – an underappreciated entity in thyroid-associated orbitopathy.
Savar LM, Menghani RM, Chong KK, et al.
ARCHIVES OPHTHALMOLOGY
2012;130:1566-9

British Journal of Ophthalmology

Intravitreal injections: in-theatre or in-office?
Reviewed by: Jonathan Chan
Feb/Mar 2013 (Vol 19 No 5)
 

This is a retrospective comparative cohort study conducted between March 2006 and March 2012, of all patients treated consecutively by single vitreoretinal surgeon with intravitreal injection with either ranibizimab or bevacizumab for any recognised clinical indication. All of the injections were recorded prospectively on an electronic medical records system and the total number of cases was extracted from the reports system into location-specific grouping (i.e. in office vs. in theatre). The total number of intravitreal injections given in theatre between 2006 and 2008 was retrieved by reviewing and cross-referencing injection log-books, billing records and hospital-based electronic records systems. From 2008 to March 2012 the total number of injections was similarly retrieved by reviewing the in-office electronic records system and all the injections were grouped according to the procedure code, injection type and preparation use. Over the six-year period, 12,249 injections were performed. Just over 3,370 of these were performed in the in-office procedure room, compared with 8,873 in the operating theatre. There were four cases of infective endophthalmitis compared with none of the 8,873 injections performed in theatre (P=0.006). In order to permit the estimation of relative risk, one case of endophthalmitis was added to each group. The relative risk of developing endophthalmitis while intravitreal injection was performed in-office compared to in-theatre was 13.1 for culture positive endophthalmitis. This represents a significantly lower risk of endophthalmitis from in-theatre injections compared to in-office. The authors concluded that the in-theatre environment is a clinically appropriate location for an intravitreal injection procedure and is associated with a significantly lower risk of infective endophthalmitis in the single-surgeon comparative cohort study. However, they also commented that any perceived disadvantages of the in-office environment (infection risk, lack of accreditation, lack of recognised theatre processes and systems) were therefore outweighed by the clinical need for treatment (as compared with no treatment).

Reference

Intravitreal injections: is there benefit for a theatre setting?
Abell RG, Kerr NM, Allen P, Vote BJ. 
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96:1474-8.

Intravitreal injections: is there benefit for a theatre setting?
Abell RG, Kerr NM, Allen P, Vote BJ. 
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96:1474-

Clinical and Experimental Ophthalmology

Uveitis associated with latent TB
Reviewed by: Kwesi Amissah-Arthur
Feb/Mar 2013 (Vol 19 No 5)
 

This retrospective study by Ang et al. set out to identify features that would make the diagnosis of uveitis associated with tuberculosis (TB) easier. The gold standard for the diagnosis of uveitis-related TB relies on culture, acid-fast bacilli or polymerase chain reaction evidence of mycobacterium tuberculosis in ocular samples. These tests are not overly sensitive and some patients in developed countries do not have positive ocular samples. The uses of clinical signs in combination with other investigations are studied in this paper. All patients seen at the Singapore National Eye Centre from 1st January, 2000 to 31st December, 2008, who had been treated with anti-tuberculous medication for six months, had a positive tuberculin skin test and met other inclusion criteria, were matched for age, sex and anatomical location of uveitis to control subjects who had a negative tuberculin skin test and had never received anti-tuberculous medication. Sixty-two patients and 72 controls were studied. The clinical signs analysed were: type of keratic precipitate, extent of continuous posterior synechiae, presence of iris nodules, presence of concomitant anterior scleritis, anterior chamber activity, chorioretinal involvement, serpiginous like choroiditis, retinal vasculitis, vitritis, optic disc hyperaemia, optic disc swelling and vitreous snow balls. The investigations analysed were: Mantoux test, interferon-gamma release assay (IGRA) and chest x-rays. Participants were divided into two groups dependent on whether they had predominantly anterior or posterior segment (PS) inflammation. Statistical analysis performed included sensitivity, specificity and likelihood of association with tuberculosis of various clinical signs. The significant signs found on univariate analysis were subsequently used in a multivariate logistic regression model. In patients with anterior uveitides, the presence of extensive PS (P=0.015) and anterior scleritis (P=0.014) were significantly associated with latent TB. On multivariate analysis, extensive posterior synechiae (P=0.036) and anterior scleritis (P=0.047) were independently associated with latent TB. Similarly, a positive IGRA was significantly associated (P=0.015). In patients with posterior segment inflammation patients with low-grade anterior chamber (AC) activity (P<0.001), severe vitritis (P=0.027) and retinal phlebitis (P=0.005) were significantly associated with latent TB. On multivariate analysis, a low-grade AC activity (P=0.012), retinal phlebitis (P=0.001) and severe vitritis (P=0.038) were clinical signs independently associated with latent TB. A positive IGRA was also significantly associated with latent TB. On the other hand, the presence of retinitis was less likely to be associated with latent TB. Combining the clinical signs above with a positive interferon-gamma release assay and tuberculin skin test improved the diagnostic performance in both groups (area under the receiver operator characteristic curve for Group A=0.779; Group B=0.789). The authors state the inherent limitations of performing this analysis on retrospective data. However, they are quick to point out that they used stringent criteria to define uveitis and that there were no cases of idiopathic uveitis in their control group that could harbour latent TB and affect the analysis. This paper aims to improve the diagnostic certainty when dealing with cases of presumed TB. The diagnosis of ocular TB is challenging due to the protean clinical manifestations, this paper aims to highlight the clinical signs and investigations that give the highest yield in diagnosing latent TB.

Reference

Clinical signs of uveitis associated with latent tuberculosis.
Ang M, Hedayatfar A, Zhang R, Chee S-P.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(7):689-96. 

Cornea

Comparison of LCAG transplantation and other techniques
Reviewed by: Sharmina Khan
Feb/Mar 2013 (Vol 19 No 5)
 

This meta-analysis compared the outcomes of limbal conjunctival autograft (LCAG) with other techniques used in pterygium surgery. Thirteen randomised controlled trials were identified. The odds ratio pooled from all the studies showed that recurrence rates were lower in LCAG compared with bulbar conjunctival autograft (CAT), bare sclera technique or intraoperative mitomycin C. There was no statistically significant difference in the recurrence rates after LCAG and amniotic membrane transplant (AMT). The results were of LCAG were compared with mitomycin C (MMC) or bare sclera in primary pterygia and CAT or AMT in both primary and recurrent pterygia. The use of AMT is controversial. Pterygium is widely cited as a local limbal deficiency associated with stem cell loss based on publications by Dushku N, 1989 and Tseng SC, 2004, therefore supporting the LCAG procedure. However, there is no evidence that including limbal epithelial cells in the autograft repopulates the supposed stem cell loss.

Reference

Comparison of pterygium recurrence rates after limbal conjunctival autograft transplantation and other techniques: meta-analysis.
Zheng K, Cai J, Jhanji V, Chen H.
CORNEA
2012;31(12):1422-7.

Comparison of pterygium recurrence rates after limbal conjunctival autograft transplantation and other techniques: meta-analysis.
Zheng K, Cai J, Jhanji V, Chen H.
CORNEA
2012;31(12):1422-7.

Cornea

Ocular HOA after pterygium excision with conjunctival autograft
Reviewed by: Sharmina Khan
Feb/Mar 2013 (Vol 19 No 5)
 

This group reports that pterygium excision and conjunctival autograft plus corneal polishing can significantly reduce pterygium induced higher order aberrations (HOA) by a single surgeon. All patients underwent primary nasal pterygium surgery (18 eyes of 16 patients). Patients with previous anterior segment surgery, trauma, ocular surface inflammation, contact lens wear, severe blepharitis / dry eye, recurrent pterygia, corneal pathology (e.g. keratoconus) were excluded. The procedure was carried out under topical anaesthesia and lidocaine 2%/1:10000 adrenaline injection into pterygium body and upper bulbar conjunctiva. Pterygium was excised at the neck and head sheared from corneal surface followed by a diamond burr to polish the corneal surface. The conjunctival autograft was oversized by 1mm compared to the scleral bed and secured with 8/0 vicryl interrupted sutures. Postoperatively all patients used g. Ofloxacin 0.3% and g. Dexamethasone 0.1%. They did not report any complications. Uncorrected visual acuity improved in the late postoperative period. Refractive astigmatism reduced postoperatively. The axis of astigmatism altered. Preoperatively the majority were either with-the-rule or oblique astigmatism and the minority against-the-rule; whereas, postoperatively, over half were with-the-rule and the minority oblique astigmatism. They previously reported HOA correlated with increase in pterygium size. They conclude that HOA particularly total coma and trefoil significantly reduce in the early postoperative period and in the late postoperative period total HOA were reduced except for spherical aberrations. These findings were irrespective of pterygium size. Change in HOA continue beyond one year. They conclude that HOA continue to change and refractive procedures should be carried out at least one year after pterygium excision.

Reference

The change in ocular higher-order aberrations after pterygium excision with conjunctival autograft: a 1-year prospective clinical trial.
Gumus K, Topaktas D, Goktas A, et al.
CORNEA
2012;31(12):1428-31.

Experimental Eye Research

Statins control diabetic retinopathy
Reviewed by: Graham Wallace
Feb/Mar 2013 (Vol 19 No 5)
 

Diabetic retinopathy (DR) is a complication of diabetes and despite much research the mechanisms of initiation and progression are poorly understood. Loss of pericytes which are fundamental to the tight junctions found in retinal vessels, with increased permeability has been implicated. However, so has microvascular ischaemia and new vessel growth. Whatever the cause, DR is induced when the balance between endothelial cell damage and repair is dysfunctional. Repair is induced by endothelial progenitor cells (EPC), which circulate in the blood. Simvastatin has been reported to increase stem cell mobilisation from bone marrow, and has proved an effective treatment in myocardial infarction and brain ischaemia. This paper addresses whether simvastatin can influence DR in an animal model. DR was induced in rats by sub-cutaneous administration of strepotozotocin. Results showed that EPC were significantly lower in rats with DR compared to controls, an effect that was reversed by simvastatin. Treatment also reduced expression of angiopoietin-1 and -2 mRNA while increasing eNOS mRNA. Histologically, simvastatin treated animals showed decreased oedema in retinal tissues. These results suggest that EPC numbers may be a marker for DR and that simvastatin treatment may be a possible therapy for this sight-threatening condition.

Reference

Simvastatin increases circulating endothelial progenitor cells and reduced the formation and progression of diabetic retinopathy in rats.
Zhang W, Yan H. 
EXPERIMENTAL EYE RESEARCH
2012;105:1-8.

Simvastatin increases circulating endothelial progenitor cells and reduced the formation and progression of diabetic retinopathy in rats.
Zhang W, Yan H. 
EXPERIMENTAL EYE RESEARCH
2012;105:1-8

Eye

Glaucoma referral refinement
Reviewed by: John Brookes
Feb/Mar 2013 (Vol 19 No 5)
 

Glaucoma referrals continue to increase with a large proportion of false positive referrals, exacerbated by the National Institute for Clinical Excellence (NICE) guidelines published in 2009 and the Association of Optometrists referral guidance. With the cost savings that the NHS will have to find over the next three years, ophthalmology services will need to find new and innovative methods to maximise capacity. This scheme developed by the Portsmouth glaucoma service involved six specialist local optometrists. Referrals were scrutinised by one glaucoma consultant, who determined whether the patient was appropriate to be sent to a referral refinement scheme, or seen directly in the hospital eye service (HES). Within the referral scheme, patients underwent a series of tests and the results were then sent to the consultant digitally in the form of a ‘virtual clinic’ and the appropriate follow-up made. Overall, 94% of the digital images could be graded and only 11% of patients attending the ‘virtual clinic’ were accepted into the HES, with 89% being discharged for community follow-up. The evaluation audit consisted of five arms, ranging from the point of referral from the community optometrist, to the outcome in the HES. Previous studies have shown that the positive predictive value (PPV) of direct referrals to the HES in an unrefined scheme was 0.37, whereas this process increased the PPV to 0.78. The refinement scheme clearly demonstrated an ability to streamline referrals, minimising the burden on the HES. The scheme has also increased capacity, releasing over 1400 clinic slots per year for the Trust and produced a cost saving of £244,200 per year. New and innovative schemes, integrating hospital services with specialist and community optometrists is likely to incur significant cost savings, increase capacity for true glaucoma cases and maintain high quality care within the NHS.

Reference

The Portsmouth-based glaucoma refinement scheme: a role for virtual clinics in the future?
Trikha S, Macgregor C, Jeffrey M, Kirwan J. 
EYE
2012;26:1288-94.

The Portsmouth-based glaucoma refinement scheme: a role for virtual clinics in the future?
Trikha S, Macgregor C, Jeffrey M, Kirwan J. 
EYE
2012;26:1288-94

Investigative Ophthalmology and Visual Science

Activation of rectus extraocular muscles during head tilt
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors have sought evidence of selective compartmental activation of rectus extraocular muscles during head tilt in normal subjects. The paper considers the possibility that horizontal rectus muscles may be capable of generating cyclovertical movements, including sensory torsion. Twenty-six subjects underwent high resolution magnetic resonance imaging (MRI) scan in 90 degrees right side down and left side down head tilt positions while lying on the scanner bed. Twelve subjects contributed data to the analysis. The study provides functional data supporting differential compartmental function in a rectus extraocular muscle. All four rectus muscles exhibited nonuniform mass distributions across their long transverse widths, approximating 7-15% asymmetry between the larger and smaller halves. Only the lateral rectus exhibited striking functional asymmetry, although behaviour of the medial rectus maximum cross-section was also asymmetrical at a lower level of significance. MRI demonstrated that ocular counter rolling is associated with contractile activity in the inferior but not superior lateral rectus compartment. Analysis of small variations in horizontal and vertical eye position during counter rolling indicated that this activity in the lateral rectus inferior compartment is not attributable to changes in gaze direction. Selective activation of the two compartments may contribute to noncommutative torsion during the vestibule ocular response.

Reference


Differential lateral rectus compartmental contraction during ocular counter rolling.
Clark RA, Demer JL.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(7):2887-96.

Differential lateral rectus compartmental contraction during ocular counter rolling.
Clark RA, Demer JL.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(7):2887-96.

Investigative Ophthalmology and Visual Science

Left-right asymmetries in saccade parameters
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors conducted a systematic investigation of the latency, gain and peak velocity of reactive and voluntary saccades, taking eye and hand dominance into account. Forty-five subjects were divided into four groups dependent on hand and ocular dominance. The results showed a left-right asymmetry in saccade gain and peak velocity rather than on saccadic latency. Rightward saccades were larger than left for the right eye. Individual and averaged data consistently showed right eye groups have faster rightward saccades regardless of the dominant hand. Left eye groups had faster leftward saccades. Left-right asymmetry can be explained by naso-temporal differences for some subjects and by eye dominance in others.

Reference

Are there any left-right asymmetries in saccade parameters? Examination of latency, gain and peak velocity.

Vergilino-Perez D, Fayel A, Lemoine C, et al.

INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 

2012;53(7):3340-8.

Are there any left-right asymmetries in saccade parameters? Examination of latency, gain and peak velocity.
Vergilino-Perez D, Fayel A, Lemoine C, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(7):3340-

Investigative Ophthalmology and Visual Science

Radial deformation hyper acuity task as a clinical tool
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The aim of the study was to determine whether the radial deformation hyper acuity task could be used as a clinical tool to detect and monitor strabismus amblyopia in young children. They evaluated the sensitivity and specificity of the radial deformation shape discrimination task for strabismus amblyopia between the ages of three and 17 years using optotype visual acuity as the gold standard. They examined the relationship between hyper acuity deficits and optotype visual acuity deficits in amblyopic children in order to evaluate whether the hyper acuity task could be used to quantify severity of amblyopia and monitor response to treatment. Of 51 children tested, a 0.5 degree radius eight radial deformation pattern had 83% sensitivity and 71% positive predictive value for strabismus amblyopia. Amblyopic deficits with this pattern were directly proportional to optotype visual acuity deficits. The results support the potential to utilise this test to detect and monitor amblyopia in infants and preschool children.

Reference

Abnormal radial deformation hyper acuity in children with strabismus amblyopia.
Subramanian V, Morale SE, Wang YZ, Birch EE.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(7):3303-8.

Abnormal radial deformation hyper acuity in children with strabismus amblyopia.
Subramanian V, Morale SE, Wang YZ, Birch EE.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(7):3303-8

Investigative Ophthalmology and Visual Science

Rasch analysis of AS-20 questionnaire
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

Rasch analysis provides a method to appropriately weight responses of each questionnaire item and rescale a health related quality of life instrument to a linear interval scored instrument by exploring the probability of individual responses in relation to the ability of individual subjects and difficulty of each item on the instrument being used. Rasch analysis was used to evaluate and refine the AS-20 questionnaire. Three hundred and forty-eight questions were completed by adult strabismus patients. The results indicate that the AS-20 questionnaire could benefit from subscale restructuring and reduction of items within the predefined subscales and two function subscales (18 items overall). This would result in four subscales of self perception, interaction, reading function and general function and four response options of never / rarely, sometimes, often and always.

Reference

Evaluation of the adult strabismus-20 (AS-20) questionnaire using Rasch analyisis.
Leske DA, Hatt SR, Liebermann L, Holmes JM.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(6):2630-9.

Evaluation of the adult strabismus-20 (AS-20) questionnaire using Rasch analysis.
Leske DA, Hatt SR, Liebermann L, Holmes JM.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE 
2012;53(6):2630-9.Evaluation of the adult strabismus-20 (AS-20) questionnaire using Rasch analysis

Journal of Glaucoma

Partially successful filtering surgery slows down visual field progression
Reviewed by: Lorraine North
Feb/Mar 2013 (Vol 19 No 5)
 

The authors describe a retrospective review of 206 treated glaucoma patients divided into two groups. Group A with greater than five visual fields done before glaucoma filtration surgery and group B with greater than five visual fields done after filtration surgery. Group B was further divided into those then requiring postoperative topical hypotensive therapy and those that did not. Progression of visual field was determined by a threshold sensitivity decline of two or more adjacent test locations in the same hemifield. Their results showed that there was a greater rate of progression in group A compared to group B but no significant difference between the group B sub-groups. This study shows that the effects of filtering surgery reduces the rate of disease progression even if adjunctive glaucoma medical therapy is required.

Reference

Effect of successful and partly successful filtering surgery on the velocity of glaucomatous visual field progression.

Francisco F, De Moraes CG, Teng CC, et al.

JOURNAL OF GLAUCOMA

2012;21:615-8.

Journal of Pediatric Ophthalmology and Strabismus

Anterior segment changes following strabismus surgery
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors examined the effect of extraocular muscle surgery on anterior segment measurements. Changes in measurements after strabismus surgery were quantitively compared with regard to the type of strabismus surgery in 42 eyes of 28 patients with exotropia. The mean preoperative angle was 27.97PD (20-40). No changes in anterior segment measurements were found at one and three months postoperatively for the overall study group. However, significant changes in anterior chamber depth were found at one month postoperatively for those with recession surgery versus recession / resection procedures. This change did not maintain significance at three months follow-up. Thus altered muscle tension caused by surgery does not have any long-term effect on anterior chamber parameters.

Reference

Comparison of preoperative and postoperative anterior segment measurements with Pentacam in strabismus surgery.

Jung JH, Choi HY.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

2012;49(5):290-4.

Journal of Pediatric Ophthalmology and Strabismus

Asthenopia with 3D TV
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors aimed to identify the ophthalmic factors that may induce 3D asthenopia and that should be detected by routine ophthalmic examination to notify the public of the warning signs associated with watching 3D television. One hundred and fifteen volunteers were aged from 18-55 years. An asthenopia group comprised 14 subjects (12%). Symptoms of 3D asthenopia were related only to the presence of exotropia. 3D TV may induce asthenopia by exacerbating this otherwise latent deviation.

Reference

Clinical research on the ophthalmic factors affecting 3D asthenopia.

Kim S-H, Suh Y-W, Song J-S, et al.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS 

2012;49(4):248-53.

Journal of Pediatric Ophthalmology and Strabismus

Changes in smooth pursuit with nystagmus surgery
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

This study determined whether the static improvements to visual function provided by the tenotomy and reattachment (T&R) procedure also have beneficial effects on the smooth pursuit of patients with infantile nystagmus syndrome (INS). The results from three patients indicate that T&R does not allow patients with INS to pursue targets faster although T&R may in some cases allow patients with INS to acquired moving targets faster in a specific direction. Static visual function and saccadic performance improved in all three patients. However, post T&R pursuit responses seemed to be immune to the visually superior input to the system.

Reference

Smooth-pursuit changes after the tenotomy and reattachment procedure for infantile nystagmus syndrome: model predictions and patient data.

Wang ZI, Dell'osso LF, Prakash S, Chen X.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS 

2012;49(5):295-302.

Journal of Pediatric Ophthalmology and Strabismus

Esotropia with high AC/A
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

Discussion of various scenarios of high AC/A ratio esotropia with different deviations and refractive errors. Consideration of full correction of hypermetropia with or without bifocals and indications for surgery.

Reference

Management of high AC/A ratio esotropia.
Morrison DG, Olitsky SE, Raab EL.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(5):265-8.

Journal of Pediatric Ophthalmology and Strabismus

Intracranial pathology causing infantile nystagmus
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The purpose was to assess the yield of using magnetic resonance imaging (MRI) as part of the nystagmus investigation for young children in detecting the presence or absence of intracranial pathology in a retrospective study of 26 patients. Nystagmus was noted from birth to 1.6 years (mean 0.5 years). Eighty-five percent was bilateral and general health was normal in 20 cases. Three patients (12%) had significant MRI findings and all showed temporal optic nerve head pallor on fundus examination. These children had bilateral torsional nystagmus or bilateral horizontal pendular nystagmus. Early childhood nystagmus by itself was not associated with intracranial pathology. The accompanying presence of temporal optic disc pallor was a risk factor for intracranial disease. Type of nystagmus did not predict intracranial pathology.

Reference

Intracranial pathology in young children with apparently isolated nystagmus. 

Shammari MA, Elkhamary SM, Khan AO. 

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS 

2012;49(4):242-6.

Journal of Pediatric Ophthalmology and Strabismus

Ocular findings in CMV
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors performed a literature study to highlight the ophthalmological symptoms at birth and at follow-up for cases of congenital cytomegalovirus (CMV) and discuss treatment options and screening options. The review considers transmission, systemic manifestations, ophthalmological findings, diagnosis, vaccination, medical treatment and treatment effect on retinitis. Approximately 90% exhibit no clinical abnormalities at birth. Ophthalmic signs are seen in a large percentage of symptomatic patients including chorioretinitis, optic atrophy and cortical visual impairment.

Reference

Ophthalmological findings in congenital cytomegalovirus infection: when to screen, when to treat?
Ghekiere S, Allegaert K, Cossey V, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(5):274-82.

Journal of Pediatric Ophthalmology and Strabismus

Refractive error after childhood IOL implant
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

Refractive changes after cataract surgery and intraocular lens (IOL) implantation are reported to provide information to predict what refractive change to expect and what IOL power to select at various ages in Asian children. The authors undertook a retrospective study of 32 eyes of 25 patients: 26 developmental cataracts, three traumatic and three iatrogenic. Six were aged up to two years, 11 aged three to five years, five aged six to eight years, three aged nine to eleven years and seven aged 12-17 years. Difference in total change in refraction and rate of change of refraction were statistically significant among different age groups. The youngest children had larger myopic shift rates. Overall myopic shift, sex, laterality, type of cataract, postoperative visual acuity, material of IOL, primary or secondary IOL implantation were not significant factors for the postoperative refractive change. The results support under-correction of young children aiming for hypermetropic corrections. They recommend aphakia with contact lens correction for children aged up to one year and secondary IOL implantation when older. Refractive development of the pseudophakic eye was not significantly different from the fellow phakic eye.

Reference

Refractive changes after pediatric intraocular lens implantation in Hong Kong children.

Yam JC, Wu PK, Ko ST, et al.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS

2012;49(5):308-13.

Journal of Pediatric Ophthalmology and Strabismus

Strabismus in spina bifida
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The purpose of this study was to investigate what factors observed in individuals with strabismus in spina bifida (SBM) are linked to the presence of strabismus. One hundred and twelve patients with SBM underwent ophthalmic examination. Ocular alignment findings were available for 107 patients. Thirty-nine percent had strabismus with esotropia occurring more than exotropia in two thirds of cases. Twenty-six percent had nystagmus. Ninety-four percent had hydrocephalus. Prevalence of strabismus was higher for those who had undergone at least one additional surgical procedure for shunt failure than for those who had never required a shunt revision. They found that individuals with upper level spinal lesions had increased risk of strabismus and nystagmus. Other significant factors relating to strabismus were lower birth weight and short gestational age.

Reference

Factors associated with strabismus in spina bifida myelomeningocele.
Anderson HA, Stuebing KK, Buncic R, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(5):284-9.

Journal of Pediatric Ophthalmology and Strabismus

Treatment of conjunctivitis outbreak
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

A description is given of the spectrum of bacterial pathogens isolated from a conjunctivitis outbreak in a child welfare agency. The authors report the first outbreak due to pasteurella canis (PC) and granulicatella adiacens (GA) which was successfully treated with ophthalmic solutions of vancomycin or gentamycin according to the antibiogram. Fourteen children with a median age of three months had conjunctivitis resistant to empirical treatment. The conjunctival culture positive rate was 35.7% and the most common pathogen was PC. For positive culture eyes, treatment was with ophthalmic solutions of vancomycin or gentamycin according to the sensitivity test results. Previous applied multiple treatments were stopped in eyes with negative conjunctival cultures. All improved clinically over approximately three months.

Reference

Pasteurella canis and granulicatella adiacens conjunctivitis outbreak resistant to empirical treatment in a child welfare agency.

Balikoglu-Yilmaz M, Yilmaz T, Esen AB, et al.

JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS 

2012;49(5):314-9.

Journal of Refractive Surgery

Piggyback IOL to correct refractive error following cataract surgery
Reviewed by: Amit Patel
Feb/Mar 2013 (Vol 19 No 5)
 

The authors report outcomes of a sulcus piggyback lens (Sulcoflex, Rayner, UK) in 15 pseudophakic eyes (of 13 patients). Three eyes were implanted with the aspheric lens (653L) and 13 eyes with the toric version (653T). The multifocal lens was not used in this series. All surgery was performed a minimum of three months following the initial surgery and following two stable refractions. Mean preoperative uncorrected distance visual acuity (UDVA) was 20/55 and all patients achieved >20/32 UDVA three months postoperatively. Preoperative mean spherical and astigmatic errors were 1.07±0.83 diopters (D) and -1.45±0.98 D, respectively. Postoperative mean sphere and astigmatism at three months were -0.25±0.38 D and -0.50±0.57 D, respectively. All patients experienced an improvement in UDVA and no loss of uncorrected or corrected acuity was noted. All patients were within 1.00 D of attempted correction, with 93% within 0.50 D. No intraoperative complication occurred. Postoperatively, one eye had raised intraocular pressure and three eyes had anterior chamber flare. No lens tilt or rotation was observed. The authors address the limitations of their study (small sample size, retrospective, short follow-up and subjective assessment of lens alignment/stability). They conclude that the lens offers an effective and predictable option for enhancing postoperative refractive results and reducing spectacle dependence for distance after surgery. Although none of the 15 eyes had previously undergone laser refractive surgery, the authors suggest that the Sulcoflex lens may be used to correct post-cataract surgery refractive errors in this group of patients.

Reference

Correction of undesirable pseudophakic refractive error with the Sulcoflex intraocular lens.

Falzon K, Stewart OG. 

JOURNAL OF REFRACTIVE SURGERY 

2012;28(9):614-9.

Ophthalmic Genetics

Corticosteroid-induced ocular hypertension
Reviewed by: Nana Theodorou
Feb/Mar 2013 (Vol 19 No 5)
 

The use of intravitreal triamcinolone acetonide (IVTA) has been reported as a potentially effective local treatment for macular oedema secondary to diabetes, uveitis and some retinal vascular disorders, but the administration of exogenous glucocorticoids like IVTA may lead to ocular hypertension in up to 40% of cases. It has been suggested that the steroid response may be a heritable alteration of glucocorticoid sensitivity. This retrospective case-control study of 102 Dutch patients treated with 4.0mg IVTA looked at the genotypes of three single nucleotide polymorphisms: rs7759778 and rs1406945 in SFRS3, and rs2968909 in FKBP4. The patients were divided into an intraocular hypertension group (intraocular pressure >21mmHg within a year after IVTA) and a non-intraocular hypertension group. There were no significant differences in demographic characteristics or medical history between the two study groups. None of the single nucleotide polymorphisms were found to be significantly associated with the disease as no difference was revealed either in the genotype or allele frequencies between responders and non-responders. The authors conclude that this study does not identify strong associations with genetic variants in several candidate genes for steroid response. They propose that additional studies, such as genome-wide association studies or next-generation sequencing, are required to understand the mechanisms underlying the pathogenesis of corticosteroid-induced ocular hypertension. 

Reference

Analysis of single nucleotide polymorphisms in the SFRS3 and FKBP4 genes in corticosteroid-induced ocular hypertension.

Hogewind BF, Micheal S, Bakker B, et al.

OPHTHALMIC GENETICS

2012;33(4):221-4.

Ophthalmology

Intracameral phenylephrine 1.5% for floppy iris syndrome
Reviewed by: Brian Ang
Feb/Mar 2013 (Vol 19 No 5)
 

The authors report on a two-centre prospective, randomised comparative case series of fellow eyes receiving intracameral phenylephrine 1.5% during cataract surgery as prophylaxis against intraoperative floppy iris syndrome (IFIS) secondary to tamsulosin. Eighty-four eyes of 42 patients who were on tamsulosin were evaluated. One eye of each patient was randomised to receive non-preserved intracameral phenylephrine 1.5% at the start of surgery while the fellow eye would receive balanced salt solution (BSS) as control. In the control group, if significant iris prolapse or pupil constriction occurred, intracameral phenylephrine 1.5% would be given during surgery. None of the eyes receiving prophylactic intracameral phenylephrine 1.5% showed any of the features typical of IFIS (triad of iris billowing, iris prolapse, pupil miosis). In the control group, 88.1% (37/42 eyes) demonstrated at least one feature of IFIS during surgery, with 61.9% (26/42) having all three IFIS features and 54.8% (23/42) requiring ‘rescue’ intraoperative intracameral phenylephrine 1.5%. Rescue phenylephrine was successful in restoring iris rigidity and pupil dilatation almost back to the original size; surgical manipulation with hooks or rings was thus not required in any of these control eyes. The use of phenylephrine was also not associated with any changes in mean arterial blood pressure and pulse rate during surgery or endothelial cell count three months after surgery. This well-designed study adds to the growing body of evidence for the use of intracameral phenylephrine as a simple, safe and cheap yet effective prophylaxis method for IFIS.

Reference

Intracameral phenylephrine 1.5% for prophylaxis against intraoperative floppy iris syndrome: prospective, randomized fellow eye study.

Lorente R, de Rojas V, de Parga PV, et al.

OPHTHALMOLOGY

2012;119:2053-8.

Ophthalmology

Statin use and open angle glaucoma
Reviewed by: Brian Ang
Feb/Mar 2013 (Vol 19 No 5)
 

The authors report on a retrospective longitudinal cohort study of 524,109 patients with hyperlipidaemia based on data from a nationwide health care claims database. Multivariate analyses was performed for these patients, looking at the risk of developing open angle glaucoma (OAG), the risk of progression from glaucoma suspect to OAG and the need for glaucoma medications and glaucoma surgery. Patients who took statins continuously for two years had a 8% reduction in OAG risk compared to those who did not. Patients diagnosed as glaucoma suspects had a 9% reduction in the risk of progression to OAG if they took statins continuously for two years. The requirement for glaucoma medications reduced by 0.4% for every additional month of statin use. However, there was no significant difference in the need for glaucoma surgery among statin and non-statin users. These findings were not replicated with other lipid-lowering medications, suggesting that the apparent protective effect of statins is unlikely to be due to their lipid lowering effects. Although the results are interesting, one has to be cautious about the limitations of the study, which were commented upon by the authors. The three main limitations are that the diagnosis of OAG could not be confirmed from this database alone, potential selection bias because the study population is one with health insurance, and the possibility of medication non-compliance. 

Reference

The relationship between statin use and open-angle glaucoma.

Stein JD, Newman-Casey PA, Talwar N, et al.

OPHTHALMOLOGY

2012;119:2074-81.

Opthalmology

BRAVO and CRUISE trials: vision-related function
Reviewed by: Brian Ang
Feb/Mar 2013 (Vol 19 No 5)
 

The Ranibizumab for the Treatment of Macular Edema following Branch Retinal Vein Occlusion: Evaluation of Efficacy and Safety (BRAVO) and the Central Retinal Vein Occlusion Study: Evaluation of Efficacy and Safety (CRUISE) trials have revolutionised the way macular oedema is treated after retinal vein occlusions. The results from the trials have unequivocally demonstrated the benefit of intravitreal ranibizumab in improving visual acuity in eyes with vein occlusions. The authors for the present study report on the impact of ranibizumab treatment based on self-reported visual function using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). The NEI-VFQ-25 looks at various aspects of visual function including general vision, difficulty with near activities, driving, dependency, role function, social function, mental health, peripheral vision, colour vision and eye pain. The higher the score, the better the self-reported visual function. Data from the 397 BRAVO and 392 CRUISE patients were analysed using the intention-to-treat approach. In general, there was a greater improvement in the NEI-VFQ-25 score across most of subscales in patients treated with ranibizumab than with sham. The improved scores at six months with ranibizumab were sustained through to 12 months (with retreatments as required). Patients originally randomised to sham treatment who subsequently received ranibizumab showed an improvement in the NEI-VFQ-25 score, but the level of improvement at 12 months was not at the same level as those who had been randomised to ranibizumab treatment. This report confirms that for vein occlusion patients with macular oedema, an improvement in visual acuity after ranibizumab treatment was accompanied by an improvement in vision-related function.

Reference

Improved vision-related function after ranibizumab for macular edema after retinal vein occlusion: results from the BRAVO and CRUISE trials.

Varma R, Bressler NM, Suner I, et al.

OPHTHALMOLOGY

2012;119:2108-18.

Orbit

Diagnosing orbital metastatic carcinoid using Indium-Octrotide Imaging
Reviewed by: Konal Saha
Feb/Mar 2013 (Vol 19 No 5)
 

This article reports two cases of the rare condition of orbital carcinoid metastasis, together with a discussion of the value of Indium-Octreotide Imaging (IOI). The first patient presented with headaches, proptosis and limited abduction and was found to have a lateral rectus mass on CT scan. Biopsy revealed a neuroendocrine tumour confirmed to be a carcinoid tumour by further investigation including IOI. Interestingly, conventional CT scan did not demonstrate bony metastases detected by the IOI. The second patient presented with intermittent upper eyelid ptosis for one year. He had previously been diagnosed with ileal carcinoid and hepatic metastases. Examination revealed unilateral complete ptosis with upper eyelid swelling. A CT scan demonstrated a mass along the medial border of the levator / superior rectus complex. IOI showed an abnormally high uptake in the liver and in the region of the orbital mass. No biopsy was taken and the patient was managed conservatively. IOI is a radionuclide labelled octreotide scan, its value lies in detecting somatostatin receptor positive lesions such as carcinoid. The cases clearly demonstrate its value in patient management by diagnosing metastatic disease in the first case and preventing unnecessary biopsy in the second.

Reference

Orbital carcinoid metastasis: diverse presentations and value of Indium-Octreotide Imaging.

Mehta P, Malik S, Adesanya O, et al.

ORBIT

2012;31(6):379-82.

Orbit

Sutured compared to not sutured posterior flaps in external DCR surgery
Reviewed by: Konal Saha
Feb/Mar 2013 (Vol 19 No 5)
 

A clear and adequately powered study comparing external dacryocystorhinostomy (DCR) patency at one year in cases where the posterior mucosal flaps were sutured with those where they were not. The authors show a statistically significant result of no difference between the two groups. Their patency rates were 89-90% in both groups. Operating times in the two groups are not presented but the authors suggest not suturing the posterior flaps will make the procedure quicker and simpler.

Reference

Anastomosis of both posterior and anterior flaps or only anterior flaps in external dacryocystorhinostomy.

Türkcü FM, Öner V, Taş M, et al. 

ORBIT

2012;31(6):383-5.

Strabismus

Magnifier training for low vision
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors developed a structured training to stimulate magnifier use in young, visually impaired children aged three to six years. During the study, recordings from a small camera built in the magnifier were collected and analysed for 21 children. Two groups received training but one with the magnifier and one without. In both groups there was a shift in time looking through the magnifier from <10 seconds towards 10-30 seconds. This aided development of task-specific eye dominance in five children. They also found a reduction of the viewing distance of near visual acuity assessment. 

Reference

Effects of magnifier training evidence from a camera built in the magnifier.

Boonstra FN, Cox RFA, Reimer AM, et al.

STRABISMUS

2012;20:44-8.

Strabismus

Profile of visual function to support visually impaired children
Reviewed by: Fiona Rowe
Feb/Mar 2013 (Vol 19 No 5)
 

The authors reported the development of the profile of visual functioning as a framework for information exchange between schools and medical specialists involved in the education or care of children with impaired vision due to brain damage. They describe the activities and tasks that should be observed during therapy, early intervention activities and at local or special schools. Standardisation aids the structure of information exchange between clinicians and teachers.

Reference

Profile of visual functioning as a bridge between education and medicine in the assessment of impaired vision.

Hyvarinen L, Walthas R, Freitag C, Petz V.

STRABISMUS

2012;20:63-8.

Acta Ophthalmologica

The prevalence of cataract
Reviewed by: Nana Theodorou
Dec/Jan 2013 (Vol 19 No 4)
 

Cataract is a leading cause of blindness worldwide and a major public health problem. Age and diabetes are known risk factors especially with an ageing population and increases in the prevalence of diabetes. This study looked at the epidemiology and risk factors of cataract subgroups in type 2 diabetes mellitus with an age and gender matched control group from the same area. This study was limited to participants of Caucasian origin. A total of 275 patients with diabetes and 256 participants in the control group were included. Lens opacities were graded using the Lens Opacification Classification System II and a score ≥2 was considered as significant. The results indicated the prevalence of significant cortical, posterior subcapsular and nuclear cataract to be 65.5%, 42.5% and 48% respectively in the diabetes group. Using logistic regression analyses all types of lens opacities were strongly associated with age. Cortical lens opacity was also associated with diabetes, posterior subcapsular with HbA1c, nuclear cataract with female gender and higher heart rate. The authors conclude that cortical cataract is associated with diabetes, not necessarily defined by glucose control, whereas posterior subcapsular cataract is associated with glucose levels. Nuclear cataract was not associated with diabetes and was more frequent in women and also associated with higher heart rate.

Reference

The prevalence of cataract in a population with and without type 2 diabetes mellitus.
Olafsdottir E, Andersson DKG, Stefansson E.
ACTA OPHTHALMOLOGICA
2012;90:334-40.

Acta Ophthalmologica

Validity of noncycloplegic autorefraction
Reviewed by: Nana Theodorou
Dec/Jan 2013 (Vol 19 No 4)
 

Previous studies have shown that noncycloplegic and cycloplegic refraction results differ in childhood. In the Tehran Eye Study, noncycloplegic and cycloplegic autorefraction has been compared in a wide age range of participants from age five to over 70. This study aimed to quantitatively compare the results obtained with noncycloplegic and cycloplegic autorefraction for epidemiological purposes. The total participants were 3,501 people over the age of five years seen between August to November 2002. They all had autorefraction with and without cycloplegia, consisting of two drops of cyclopentolate 1.0% five minutes apart with autorefraction after the second drop. The results indicated that the sensitivity of noncycloplegic autorefraction for myopia was 99% but the specificity only 80.4%. In contrast, the sensitivity for hyperopia was only 47.9% but the specificity 99.4%. At all ages, noncycloplegic autorefraction overestimated myopia and underestimated hyperopia. Overestimation of myopia was highest in the 21-30 and 31-40 year groups. Underestimation of hyperopia was high up to the age of 50 but decreased with age. In conclusion, the use of noncycloplegic autorefraction in epidemiological studies leads to considerable errors relative to cycloplegic measurements except in the over 50-60s. The difference between noncycloplegic and cycloplegic measurement varies with age and refractive category and there is considerable individual variation ruling out adjusting for noncycloplegic measurements to obtain accurate cycloplegic refractions.

Reference

Validity of noncycloplegic refraction in the assessment of refractive errors: the Tehran Eye Study.
Fotouhi A, Morgan IG, Iribarren R, et al.
ACTA OPHTHALMOLOGICA
2012;90:380-6.

Cornea

Tacrolimus eye drops for dry eye
Reviewed by: Sharmina Khan
Dec/Jan 2013 (Vol 19 No 4)
 

Tacrolimus (FK506) is a macrolide and a calcineurin inhibitor. It inhibits T and B cell function and the production of pro-inflammatory cytokines IL-2, IL_3 and IFN-γ and is thought to be 100 times more potent than ciclosporin A. This study was conducted using Tacrolimus 0.03% and olive oil (Ophthalmos, Sao Paolo, Brazil). Sixteen eyes of eight patients with Sjorgen’s Syndrome used tacrolimus 0.03% twice a day 12 hours apart. Schirmer 1, tear film break-up time (BUT), dual vital staining with fluorescein and Rose Bengal were used the day before commencing treatment, day 14, 28 and 90. Patients were excluded if they had previous lid abnormaility or lid surgery, anterior chamber inflammation, previous ocular surgery, punctual occlusion, use of any topical medication other than artificial tears, any systemic or topical antibacterial therapy or anti-inflammatory systemic treatment, contact lens wear, the presence of corneal infection, any corneal diseases and pregnancy. All measurements were performed by one examiner. The results showed statistically significant improvement in Schirmer I, BUT and dual staining at 14 days and more so at 28 and 90 days. This is an interesting study, with a small but well-defined study population. However, it would have been improved with a control arm treated with high frequency artificial tears. Tacrolimus (in the NHS setting) is not appropriate to be used as first line treatment for dry eye patients given that there are other measures that should be used first using a stepladder approach to therapy.

Reference

Clinical treatment of dry eye using 0.03% Tacrolimus eye drops.
Moscovici BK, Holzchuc R, Chiacchio BB, et al.
CORNEA
2012;32:945-9.

Experimental Eye Research

Lipoxin protection of corneal stromal injury
Reviewed by: Graham Wallace
Dec/Jan 2013 (Vol 19 No 4)
 

Inflammation is an integral part of wound healing. Injury to tissue release arachadonic acid which leads to the formation of biologically active lipids such as prostaglandins and platelet activating factor (PAF). PAF induces inflammation by various mechanisms including induction of metalloproteases that breakdown tissue barriers. In corneal epithelial cells and myofibroblasts PAF induces MMP9 which inhibits wound healing. Lipoxin A4, (LXA4) also derived from arachdonic acid is anti-inflammatory and controls migration of dendritic cells (DCs) and production of interleukin (IL)-12 in vivo. In the absence of LXA4 biosynthetic pathways, the resulting uncontrolled inflammation during infection is lethal, despite pathogen clearance. LXA4 has been shown to encourage wound-healing in corneal lesions. To address the interaction of these two molecules a mouse model of injury to the anterior stroma was used where mice were treated with PAF alone, PAF plus LXA4, PAF plus an antagonist LAU-0901, or vehicle alone. The results showed that PAF inhibited wound healing, with increased MMP9 expression, a response that was blocked by LAU-0901. LXA4 led to a significant reduction in lesion size compared to PAF alone. These results support a strong protective role for LXA4 in corneal stromal injury by inhibiting inflammation and encouraging wound healing.

Reference

Lipoxin A4 inhibits platelet-activating factor inflammatory response and stimulates corneal wound healing of injuries that compromise the stroma.
Kakazu A, He J, Kenchegouda S, Bazam HE.
EXPERIMENTAL EYE RESEARCH
2012;103:9-16.

Experimental Eye Research

Mesenchymal stem cells prolong allograft survival
Reviewed by: Graham Wallace
Dec/Jan 2013 (Vol 19 No 4)
 

Another potential use of mesenchymal stem cells (MSC) for ocular tissue repair was described in a second paper. Due to immune privilege corneal transplantation is the most successive organ transplant in humans. However, when immune privilege is lost, for example in inflamed eyes graft survival is greatly reduced. MSC have been shown to be immunosuppressive in several settings, including graft versus host disease, probably due to secreted factors. In this paper the authors used a rat model of allograft rejection with Wistar rat tissue transplanted into Lewis rat donors. Recipient rats were treated with MSC alone, or MSC plus cyclosporine at various doses. The results showed that post-operative injection of MSC prolonged graft survival in part by inhibiting pro-inflammatory cells and increasing regulatory cells in the graft. Interestingly, MSC injection coupled with low-dose cyclosporine accelerated graft rejection, possibly because cytokines like interferon-g are thought to be important in MSC activation. However, high dose cyclosporine and MSC significantly prolonged graft survival. The reason for this dose-dependent response is not clear. The potential for using MSC to prolong graft survival in high-risk eyes is clear; however the interaction with cyclosporine levels needs to be addressed.

Reference

Immunomodulatory effects of mesenchymal stem cells in a rat corneal allograft rejection model.
Jia Z, Jiao C, Zhao S, et al.
EXPERIMENTAL EYE RESEARCH
2012;102:44-9.

Eye

Characteristics of retinal detachment in pseudophakic and phakic eyes
Reviewed by: John Brookes
Dec/Jan 2013 (Vol 19 No 4)
 

This is a retrospective review of an electronic database of patients aged 50 years and above presenting to the vitreo-retinal service at St Thomas’ Hospital. Baseline characterstics were recorded and compared between subgroups, which included phakic and pseudophakic eyes; the premise being that a potential strategy for exploring the link between retinal detachment and cataract surgery is to examine the clinical pattern of the retinal detachment, in terms of position, size and type of retinal break, which may suggest a difference in pathogenetic mechanisms. Previous studies have reported an increased risk of retinal detachment associated with cataract surgery, despite progress in surgical technique. The four year incidence of retinal detachment after all cataract extractions has been reported as 1.17%, with higher rates in cases of vitreous loss (4.9%) and a lower rate with phacoemulsification (0.4%). This figure is higher therefore than the number of retinal detachments expected in the normal population. The study looked at 500 cases, of which 146 were pseudophakic and 177 of the phakic eyes had cataract. In a univariate analysis, pseudophakic patients were significantly older than phakic patients but the same age as patients with cataract and in the pseudophakic group, there were a lower proportion of females and patients presenting with vitreous haemorrhage or with large or superotemporal breaks. Higher proportions of pseudophakic patients had small breaks and inferonasal breaks. Multi-variate analysis confirmed a lower chance in pseudophakia of large breaks, vitreous haemorrhage and superotemporal breaks, but higher chance of detached inferior breaks. The study adds to the literature that the patterns of retinal detachment differ between pseudophakic and phakic eyes (and also between pseudophakic and phakic eyes with cataract). The patterns of detachment in pseudophakic eyes bear some similarity to patterns seen previously in aphakic eyes and the authors conclude that the results are consistent with the notion that the event of cataract surgery itself, rather than simply the presence of a cataract, increases the risk of retinal detachment and affects the pattern of breaks.

Reference

Characteristics of rhegmatogenous retinal detachment in pseudophakic and phakic eyes.
Mahroo OAR, Dybowski R, Wong R, Williamson TH.
EYE
2012;26:1114-21.

Eye

Visual outcomes after carotid reconstructive surgery for OIS
Reviewed by: John Brookes
Dec/Jan 2013 (Vol 19 No 4)
 

Stenosis of the carotid arteries is one of the main causes of ischaemic stroke, leading to ischaemic lesions of the retina and optic nerve. The aim of this study was to determine the influence of carotid artery surgery on ocular functions and ocular blood flow in patients with ocular ischaemic syndrome (OIS) in the late post-operative period. One hundred and eighty patients with OIS underwent carotid endarterectomy, 104 having suffered from acute forms of the ischaemic disease, such as amaurosis fugax, central retinal artery occlusion and acute ischaemic optic neuropathy. Seventy-six patients had chronic forms of ocular ischaemia, such as a progressive decrease in vision, chronic ischaemic neuropathy and venous stasis retinopathy. However, patients with more advanced chronic ocular ischaemia were excluded. Parameters including visual acuity, electrophysiology and blood flow in ocular vessels were assessed. After carotid endarterectomy, the visual acuity increased in patients with the acute forms of the disease and there were also improvements in optic nerve blood flow in both acute and chronic forms of OIS. The authors have shown that carotid artery surgery effectively improves ocular blood flow in OIS in the late postoperative period.

Reference

Visual outcomes after carotid reconstructive surgery for ocular ischaemia.
Neroev VV, Kiseleva TN, Vlasov SK, et al.
EYE
2012;26:1281-7.

Investigative Ophthalmology and Visual Science

Accommodative lag in young hyperopes
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The goal was to measure the accommodative lag of 111 young human hyperopes across a wide age range to identify individuals who demonstrate inaccurate accommodation for near and who therefore may be at risk for abnormal visual development. Children were aged 3.7 to 90 months (mean 37.7 months). Accommodative accuracy was assessed using Nott retinoscopy. Three groups were identified: 1) no clinical abnormality other than bilateral spherical refractive error; 2) useable data at six months and two to three years of age; 3) clinical abnormalities. Individuals with higher hyperopia or abnormal visual development demonstrate greater accommodative lags. The authors propose that those with larger accommodative lags are the ones least likely to emmetropise, the risk of failure to emmetropise increases above 4D of hyperopia. Accommodative lag at targets distance of 57cms can be used to detect higher hyperopia, amblyopia and strabismus.

Reference

The accommodative lag of the young hyperopic patient.
Candy TR, Gray KH, Hohenbary CC, Lyon DW.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(1):143-9.

Investigative Ophthalmology and Visual Science

Driving with moderate visual impairments
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The aims were to better understand how drivers’ ability to recognise pedestrians at night is affected by moderate visual impairments (refractive blur and simulated cataracts) that maintain near acuity within levels that are typically permitted by licensing standards. The study demonstrated that drivers’ ability to see and respond to pedestrians at night is degraded by modest but common visual impairments. Blurred vision (e.g. without glasses) and simulated cataracts both reduced the ability of the drivers to recognise pedestrians, with the cataract condition having a greater impact. Cataracts reduced contrast sensitivity to a greater extent. The effects of head lamp glare effectively halved the likelihood that drivers detected the presence of a pedestrian. To maximise detection, drivers should wear optimal optical correction with early cataract surgery.

Reference

Even moderate visual impairments degrade drivers’ ability to see pedestrians at night.
Wood JM, Tyrrell RA, Chaparro A, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(6):2586-92.

Investigative Ophthalmology and Visual Science

IADLs in glaucoma and AMD patients
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The study assesses whether or not patients with visual acuity loss from age-related macular degeneration (AMD) or peripheral visual field loss from glaucoma are more likely to perform activities of instrumental activities of daily living (IADLs) with help or not at all. Sixty controls without visual loss, 84 glaucoma patients and 47 AMD patients were assessed. Overall 2% described disability in one or more IADLs whereas 28% described disability in one or more IADLs. The three activities with the highest frequency of disability were heavy housework, travelling beyond walking distance and grocery shopping. The mean number of IADL disabilities was 0.2 for controls, 0.65 for glaucoma and 1.3 for AMD. The likelihood of reporting IADL limitation increases with severe visual field loss from glaucoma and visual acuity loss from AMD.

Reference

Association of vision loss in glaucoma and age related macular degeneration with IADL disability.
Hochberg C, Maul E, Chan ES, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(6):3201-6.

Investigative Ophthalmology and Visual Science

Initial STAMP study data
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This paper presents the STAMP primary outcome data (change in refractive error) after the first and second years of the study. Eighty-five children were enrolled in to the trial. Children were randomised to single vision lenses or progressive addition lenses (PALs). Results confirm the presence of a small but significant treatment effect when children with high accommodative lag wear PALs. Absence of a rebound of the treatment effect after discontinuing PALs wear is not consistent with the mechanical tension theory but supports the hyperopia defocus theory of myopia progression. The results also are inconsistent with PAL effect being due to decreased foveal blur during near work.

Reference

A randomised trial using progressive addition lenses to evaluate theories of myopia progression in children with a high lag of accommodation.
Berntsen DA, Sinnott LT, Mutti DO, Zadnik K.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(2):640-9.

Investigative Ophthalmology and Visual Science

Ocular imaging
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The author provides a short review which considers the use of ocular imaging with confocal scanning laser ophthalmoscopy (CSLO), structured light plethysmography (SLP) and optical coherence tomography (OCT) to provide reproducible, accurate, objective and quantitative assessment of the status of the ocular structure. Early detection and early treatment are considered.

Reference

Detection and diagnosis of glaucoma: ocular imaging.
Schuman JS.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(5):2488-90.

Investigative Ophthalmology and Visual Science

Reading performance and CCTV
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This trial was conducted to investigate the effect of a concise outpatient training program on closed-circuit television (CCTV) reading performance. One hundred and twenty-two subjects were randomised and reading performance improved in all patients when reading with CCTV when compared to those reading without CCTV. The treatment group showed more improvement on reading performance tasks but differences were small and insignificant. Thus the results are inconclusive. Improvement in reading performance was predominantly caused by introducing the device. Results strongly suggest that there is no evidence for the benefit of training and improvement in reading ability mainly accrued from the patient’s own practice.

Reference

Randomised controlled trial on the effects of training in the use of closed circuit television on reading performance.
Burggraaff MC, van Nispen RM, Hoeben FP, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(4):2142-50.

Investigative Ophthalmology and Visual Science

Street crossing decisions in differently sighted pedestrians
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

In this study, the authors used a new metric to determine how well pedestrians can discriminate different vehicular gap times, to measure the accuracy (bias) and reliability of street crossing decisions made by 12 normally sighted, 10 visually impaired and 10 blind subjects under three sensory conditions: 1) visual plus auditory information; 2) visual information only; and 3) auditory information only. The results suggest that normally sighted and visual impaired subjects using conditions one and two are able to make accurate street crossing decisions. All subjects were less accurate when their street crossing decision was limited to using only auditory information. The cause of the inaccuracy with only auditory information appeared to relate to subjects overestimating the vehicular gap time.

Reference

Are normally sighted, visually impaired and blind pedestrians accurate and reliable at making street crossing decisions?
Hassan SE.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(6):2593-600.

Investigative Ophthalmology and Visual Science

Study into childhood amblyopia
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The purpose of the study was to explore the potential for treating childhood amblyopia with prolonged viewing of a binocular stimulus adapted to correlate the visual input from both eyes. Fourteen children with amblyopia were recruited and undertook a dichoptic perceptual learning task for five sessions of one hour over one week. They showed an increase in visual acuity and stereopsis. This treatment requires further longitudinal study.

Reference

An exploratory study: prolonged periods of binocular stimulation can provide an effective treatment for childhood amblyopia.
Knox PJ, Simmers AJ, Gray LS, Cleary M.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(2):817-24.

Investigative Ophthalmology and Visual Science

Using Nintendo Wii to measure head posture
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors developed a high performance, inexpensive digital head posture measuring device – infrared optical head tracker (IOHT) – that automatically measures and records the angle of head posture in real time using two Nintendo Wii remote controllers. They used the IOHT to measure the head posture of 20 normal adult subjects in one and three dimensions and evaluated its accuracy, validity and reliability in comparison to the CROM device. The results showed strong concordance with the CROM and relatively good test-retest reliability.

Reference

Nintendo Wii remote controllers for head posture measurement: accuracy, validity and reliability of the infrared optical head tracker.
Kim J, Nam KW, Jang IG, et al.
INVESTIGATIVE OPHTHALMOLOGY AND VISUAL SCIENCE
2012;53(3):1388-96.

Journal Of Cataract And Refractive Surgery

Intraocular pressure after phacoemulsification
Reviewed by: Badrul Hussain
Dec/Jan 2013 (Vol 19 No 4)
 

Intraocular pressure (IOP) in patients with acute and chronic angle-closure has been shown to decrease after phacoemulsification. A meta-analysis review has concluded that phacoemulsification may have a modest IOP-lowering effect in patients with open-angle glaucoma. This retrospective comparative case series reviewed 1683 records of patients with ICD-9/CPT diagnoses of ocular hypertension and / or open-angle glaucoma who underwent unilateral, uncomplicated phacoemulsification with the fellow eye remaining phakic for at least three years postoperatively. Preoperatively, the IOP in the surgical and fellow eyes in the 29 patients (meeting the criteria) was 15.66mmHg±3.33 (SD) and 15.64±4.23mmHg, respectively. P=0.98 in these patients with a mean age of 75.34 years. The postoperative mean IOP was noted at postoperative week one, 4.5, and postoperative year one, two and three. In this cohort of 29 patients with ocular hypertension (OHT) and glaucoma, uncomplicated phacoemulsification had no significant IOP-lowering effect compared with the unoperated fellow eye for up to three years postoperatively. More importantly, there was no difference in the mean number of postoperative IOP-lowering medications used in either eye. The authors acknowledge the limitations of the study: small sample size, no measure of anterior chamber depth (a measure of outflow facility) and selecting unilateral cataracts may have inadvertently selected occult pathologies (e.g. chronic inflammation).

Reference

Long-term effect of phacoemulsification on intraocular pressure using phakic fellow eye as control.
Chang TC, Budenz DL, Liu A, et al.
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2012;38(5):866-70.

Journal of Pediatric Ophthalmology and Strabismus

Albinism and reading skills
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

Standardised reading tests were administered to a large cohort of children and adults with albinism with normal cognition to define how low vision might independently contribute to the development of normal reading abilities. Fifty-nine subjects (41 children and 18 adults) aged four to 59 years participated. The results confirm that reading scores do not correlate with visual acuity in individuals with albinism, with the exception of fluency. Associated nystagmus did not appear to affect general reading abilities. The lower fluency suggests that in schools and work, individuals with visual loss need to be given extra time for reading tasks.

Reference

Reading skills in children and adults with albinism: the role of visual impairment.
MacDonald JT, Kutzbach BR, Holleschau AM, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49:184-8.

Journal of Pediatric Ophthalmology and Strabismus

Chemotherapy for retinoblastoma
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors report the audit of outcomes of chemotherapy during 2008 and document some of the future challenges in reducing mortality associated with retinoblastoma in the African context. Thirty-seven patients had diagnosis at a mean age of 2.9 years (0-7). Proptosis, leukocoria and orbital mass were triggers for referral. Twenty-five cases had unilateral tumour, 32% were ocular disease, 57% with orbital involvement and 11% with central nervous system (CNS) metastatic disease. Disease remission rate was 35%. One hundred percent mortality was recorded in those with disease progression. Sixty-seven percent completed chemotherapy and all of these achieved remission.

Reference

First-year experience of chemotherapy for advanced retinoblastoma in Tanzania: disease profile, outcomes and challenges in 2008.
Corrim ZI, Kajaige J, Bowman RJ, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49:76-183.

Journal of Pediatric Ophthalmology and Strabismus

Contaminated sutures
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This study aimed to document the contamination rate of suture material used in strabismus surgery and determine the efficacy of various means of antiseptic and antibiotic prophylaxis to reduce the contamination rate. Three groups were evaluated: 1) control of 61 sutures, 2) antibiotic and steroid coated (200 sutures) and 3) povidone iodine-soaked and antibiotic / steroid coated (141 sutures). Group 1 had bacterial growth in 28%, group 2 in 22% and group 3 in 9% of sutures. The latter was significant. No complications were found for group 3 and all groups were supposedly sterile suture strands at the completion of surgery. The authors assume the povidine-iodine soak to be important.

Reference

Suture contamination in strabismus surgery.
Eustis HS, Rhodes A.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(4):206-9.

Journal of Pediatric Ophthalmology and Strabismus

Costs of amblyopia screening
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

Three amblyopia screening strategies were modelled to evaluate their relative cost effectiveness when applied to a hypothetical cohort of children representative of the US birth cohort. The model used primary programmatic cost, referral rate and follow-up treatment data from two state screening programmes. The findings suggest that amblyopia screening is likely to be cost effective to a policy maker willing to pay $15000 per quality-adjusted life year (QALY) averted (assuming a QALY loss from untreated amblyopia of 0.1 per year) or $4005 per case of amblyopia vision loss averted. Areas that have established preschool screening programmes in place may wish to consider adding combined acuity and stereopsis screening. Photoscreening was more costly, but may result in greater benefits than amblyopia / strabismus screening.

Reference

The potential cost-effectiveness of amblyopia screening programmes.
Rein DB, Wittenborn JS, Zhang X, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49:146-55.

Journal of Pediatric Ophthalmology and Strabismus

Duane's syndrome
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

Retrospective analysis of demographic and clinical features of various subtypes of 441 consecutive patients with Duane’s retraction syndrome (DRS) presenting over a 10-year period. Cases were unilateral in 88% and bilateral in 12%. Type I was most common followed by types II and III. Fifty-six percent were females. Unilateral was most likely in females as well as type I. The left eye was affected in 78%, with face turn in 55%, associated ocular abnormalities in 8%, associated systemic abnormalities in 3% and up / down shoot in 43%. There was a positive family history in 8%.

Reference

Duane’s retraction syndrome: series of 441 cases.
Kekunnaya R, Gupta A, Sachdeva V, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49:164-9.

Journal of Pediatric Ophthalmology and Strabismus

Improving VA in albinism
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors sought to determine whether binocular best corrected visual acuity improved during the early school years and whether this was related to the type of albinism, ocular pigment or appearance of the macula. Sixty-five patients were reviewed and visual acuity measured at two ages of 5.5-9 years and 9.5-14 years. In the older age group, visual acuity showed significant improvement with increasing age of measurement. Better visual acuity was noted in type OCA1B than OCA2, but a strong correlation between change in visual acuity and type of albinism was not found.

Reference

Change in visual acuity in albinism in the early school years.
Dijkstal JM, Cooley SS, Holleschau AM, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(2):81-6.

Journal of Pediatric Ophthalmology and Strabismus

IO surgery and risk of contralateral IO overaction
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This study investigated the role of the location of the equator and orientation of newly attached inferior oblique (IO) muscles in the development of contralateral inferior oblique overaction (IOOA). Fourteen patients were reviewed with secondary IOOA. Seven underwent modified inferior oblique transposition onto the equator and seven underwent modified 14mm recession of the transposed inferior oblique muscle vertically behind and 10mm from the inferior rectus insertion. Despite placement of the inferior oblique muscle on the equator, 86% of patients in this group showed mild or definite IOOA in the contralateral eye. Contralateral IOOA also developed in 43% of patients in the recession group. The authors propose that contralateral IOOA may occur through a combined mechanism: transposition of the inferior oblique muscle anterior to the equator and altered vector force through the vertical orientation of the inferior oblique muscle at the modified functional insertion at the neurovascular bundle.

Reference

Inferior oblique transposition onto the equator: the role of the equator in development of contralateral inferior oblique overaction.
Kim SH, Na JH, Cho YA.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(2):98-102.

Journal of Pediatric Ophthalmology and Strabismus

Pre and post operative psychosocial effects of strabismus
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors undertook the study to assess the psychosocial effects of noticeable strabismus in Chinese adolescents and adults before and after surgical correction. Measurements were greater than 20PD for horizontal deviations. Pre and postoperative questionnaires were given with Z constructs addressing social and psychological functions. Fifty-six cases were evaluated: 23 men and 33 women, aged 14-49 years. There was no preoperative diplopia. All patients showed some preoperative psychosocial impact. Negative effects were reported for school, work, sport and social life presenting mainly as barriers to self image and inter personal relationships. Ninety-three percent had problems maintaining eye contact. Difficulty in adapting to new environments and maintaining relationships were reported. Just over 90% reported improvement after surgery.

Reference

The psychosocial effects of strabismus before and after surgical correction in Chinese adolescents and adults.
Xu J, Yu X, Huang Y, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49:170-5.

Journal of Pediatric Ophthalmology and Strabismus

Premature ocular comorbidities
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors aimed to assess the ocular morbidities of 117 children born prematurely in early childhood. Retinopathy of prematurity (ROP) was present in 22%. The results show that prevalence of visual impairment, strabismus and myopia seems to increase as the gestational age decreases. The children were divided into three groups of gestational age: 1) ≤28 weeks, 2) 29-32 weeks and 3) 33-36 weeks. The results confirm that premature children are at increased risk of ocular morbidities. High myopic eyes had statistically significantly thicker lenses than low myopic or hypermetropic eyes.

Reference

An assessment of ocular morbidities of children born prematurely in early childhood.
Goktas A, Senar EC, Sanac AS.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(4):236-41.

Journal of Pediatric Ophthalmology and Strabismus

Prism efficacy
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The purpose was to assess the effectiveness of prisms in alleviating diplopia in a large cohort with a wide range and varied aetiologies of comitant ocular misalignment, including 94 patients with concomitant horizontal, vertical and mixed deviations. The overall success rate of prism use was 88% with a lower success rate when used in exo (70%) than eso (100%), hypertropia (86%) and oblique (86%) deviations. Thirty-six percent of those with convergence insufficiency were dissatisfied with prisms. Overall, 89% continued to use prisms and 11% opted for surgery.

Reference

Effectiveness of prisms in the management of diplopia in patients due to diverse etiologies.
Tamhanker MA, Ying G-S, Volpe NJ.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(4):222-8.

Journal of Pediatric Ophthalmology and Strabismus

Simultaneous bilateral cataract surgery with IOLs
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This study was a retrospective investigation of relative cost of simultaneous bilateral cataract surgery (SBCS) versus sequential surgery and reports incidence of postoperative complications and compares the refractive outcome in 48 children operated on same day versus 48 children operated on successive days. Ninety-six children (192 eyes) were evaluated. The cost was $274 for SBCS per child and $344 for sequential surgery, with a 20% cost saving. The incidence of late postoperative complications was 37% of eyes. Fibrin formation was a frequent in each group. BSCS was a safe alternative to sequential surgery.

Reference

Simultaneous bilateral cataract surgery with IOL implantation in children in Kenya.
Gradin D, Mundia D.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49:139-44.

Journal of Pediatric Ophthalmology and Strabismus

Surgical dose for Down syndrome
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This case control study compares the effect of bilateral medial rectus using standard surgical doses in 16 children with Down syndrome with the effect of bilateral medial rectus surgery in 16 children without neurodevelopmental disorders. The results reveal a similar surgical effect. Over 24 months the difference remained clinically and statistically insignificant. The authors propose that standard surgical doses need not be modified for those with Down syndrome.

Reference

Outcomes of strabismus surgery for esotropia in children with Down syndrome compared with matched controls.
Walker Motley W, Melson AT, Gray ME, Salisbury SR.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(4):211-4.

Journal of Pediatric Ophthalmology and Strabismus

Surgical outcome for congenital SO palsy
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The aim of this study was to establish residual symptoms and surgical results of patients whose vertical muscles were operated on in 48 cases with the diagnosis of unilateral congenital superior oblique palsy. Seventy-four percent had excellent postoperative results (0-3PD), 21% with a good result (4-7PD) and 5% with a poor result (>7PD). Fifty-eight percent had facial asymmetry. Surgery included myectomy and concomitant inferior oblique disinsertion or myectomy and concomitant inferior oblique disinsertion plus superior rectus recession of the ipsilateral eye.

Reference

Residual symptoms after surgery for unilateral congenital superior oblique palsy.
Caca I, Sahim A, Cingu A, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(2):103-8.

Ophthalmic Genetics

LOXL1 gene and primary open angle glaucoma
Reviewed by: Nana Theodorou
Dec/Jan 2013 (Vol 19 No 4)
 

Primary open angle glaucoma (POAG) is the most prevalent form of glaucoma globally. The primary aim of this study was to investigate whether major single nucleotide polymorphisms (SNPs) in the LOXL1 gene associated with pseudoexfoliation glaucoma are associated with POAG in the Saudi Arabian population. Entry criteria for control subjects were age >40, normal intraocular pressure, open angles on gonioscopy and normal optic nerves on examination. The regions of the LOXL1 gene associated with pseudoexfoliation glaucoma were sequenced in 96 POAG cases and 101 healthy controls from a Saudi Arabian dataset. There was no difference in allele association or genotype frequencies between cases and controls for all the three SNPs tested. Findings were similar to those reported from other parts of the world. Variants of LOXL1 did not appear to contribute to the pathogenesis of POAG in the Saudi Arabian population.

Reference

Lack of association between LOXL1 gene polymorphisms and primary open angle glaucoma in the Saudi Arabian population.
Abu-Amero KK, Osman EA, Azad MT, et al.
OPHTHALMIC GENETICS
2012;33(3):130-3.

Ophthalmology

Fear of falling in glaucoma
Reviewed by: Brian Ang
Dec/Jan 2013 (Vol 19 No 4)
 

The authors report on a prospective observational study comparing the fear of falling between 83 glaucoma subjects with bilateral visual field (VF) loss and 60 glaucoma suspects as controls. Fear of falling was evaluated with the University of Illinois Fear of Falling Questionnaire and analysed statistically with the Rasch model. For inclusion in the glaucoma group, patients needed to have a VF mean deviation (MD) of -3dB or less in both eyes and an abnormal hemifield test result or generalised reduction in sensitivity. Other assessed variables included logMAR visual acuity, contrast sensitivity using the Pelli-Robson chart, media opacities, cognitive ability (using the visually impaired version of the Mini Mental State Examination), depression symptoms (using the short version of the Geriatric Depression Scale), age, gender, body mass index (BMI), grip strength (using the Jamar hand dynamometer) and other co-morbidity. As expected, fear of falling was found to be greater in glaucoma patients, and this fear increased with greater loss of VF, even when adjusting for the other assessed variables. This was despite the fact that none of the glaucoma patients had VF loss that was severe enough to be classified as being blind. Other predictors of fear of falling were: female gender, more co-morbid illness, higher BMI and living with another person. Interestingly, the increased fear of falling from a decrease of 5dB in the VF MD of the better eye was equivalent to that of having one additional co-morbid illness; this indicates that the impact of glaucoma on the fear of falling was greater than that of the other risk factors. This study confirms the association between increased fear of falling and bilateral glaucomatous VF loss, thus further illustrating the major impact that glaucoma can have on quality of life.

Reference

Fear of falling and visual field loss from glaucoma.
Ramulu PY, van Landingham SW, Massof RW, et al.
OPHTHALMOLOGY
2012;119:1352-8.

Opththalmic Genetics

Autosomal recessive bestrophinopathy
Reviewed by: Nana Theodorou
Dec/Jan 2013 (Vol 19 No 4)
 

This article describes the phenotype and genotype of patients with autosomal recessive bestrophinopathy. Bestrophin 1 (BEST1) is a protein expressed in the retinal pigment epithelium (RPE). Mutations in the Best1 gene have been shown to be responsible for Best disease. Best macular dystrophy, also known as Best disease is inherited in an autosomal dominant manner. The typical clinical features of Best disease are central vitelliform maculopathy and a reduction in the Arden ratio of the electro-oculogram. The signs of Best disease may be symmetric between the two eyes, there may be multiple fundus abnormalities and the age of onset is highly variable. Levels of BEST1 are higher in the RPE outside the macula compared to the macular RPE. Recruits were subjects from three different unrelated families. The phenotype of these subjects was described after a complete ophthalmological examination and additional testing of the visual field, optical coherent tomography, full field electro-retinography and electrophysiology. Genetic analysis was carried out by screening the BEST1 gene for mutations by dideoxy sequencing and segregation analysis. The authors identified three previously described mutations and two potentially pathogenic changes in the BEST-1 gene. All individuals with BEST1 gene mutations had signs of maculopathy. Patients with compound heteroyzygous BEST1 mutations developed atypical forms of Best disease. Two siblings with homozygous Arg141His mutation developed symptoms of typical Best vitelliform dystrophy, while their parents had clinical features of mild maculopathy.

Reference

Phonotype and genotype of patients with autosomal recessive bestrophinopathy.
MacDonald IM, Gudiseva EA, Villanueva A, et al.
OPHTHALMIC GENETICS
2012;33(3):123-9.

Orbit

Prevention of a high skin crease following eyelid lengthening surgery
Reviewed by: Konal Shah
Dec/Jan 2013 (Vol 19 No 4)
 

The authors describe a surgical technique employed in a group of Japanese patients who underwent upper eyelid lowering for thyroid eye disease related upper eyelid retraction. They describe the technique to be 100% successful in their patient group, however, no control group is presented. The technique involves mobilisation of the preaponeurotic fat pad and suturing to the tarsal plate prior to skin crease formation with skin to tarsus sutures. The technique may well be useful in this group of patients with naturally low upper eyelid skin creases and may have a role in Caucasians during revisional surgery to reposition the skin crease or address upper eyelid hollowing.

Reference

Preaponeurotic fat advancement for prevention of unexpected higher eyelid crease in upper eyelid lengthening surgery.
Kakizaki H, Inchinose A, Iwaki M.
ORBIT
2012;31(5):299-302.

Orbit

The spectrum of amyloidosis related periocular disease
Reviewed by: Konal Shah
Dec/Jan 2013 (Vol 19 No 4)
 

An article describing a variety of cases of orbital and adnexal amyloidosis. Ten cases are described, nine of which have localised amyloidosis and one systemic disease. Presentations varied from conjunctival lesions through eyelid infiltration to orbital masses. Eight of 10 cases presented with palpebral conjunctival lesions. Biopsies were taken in all cases and seemed necessary to confirm the diagnosis. Referral to an appropriate physician for systemic investigation is discussed; a variety of treatment options being available for systemic amyloidosis. Local treatment centred on symptom relief in the form of bandage contact lenses, lubricants and surgical debulking (although recurrence can be anticipated).

Reference

Amyloidosis of the orbit and adnexae.
Al Nuaimi D, Bhatt P, Steeples L, et al.
ORBIT
2012;31(5):287-8.

Retina

Comparison of ranibizumab and bevacizumab for myopic choroidal neovascularisation
Reviewed by: Nikolaos D. Georgakarakos
Dec/Jan 2013 (Vol 19 No 4)
 

This is a prospective, single centre, double-masked randomised clinical trial carried out in Milan (Vita-Salute University of Milan) aiming to compare the effects of intravitreal bevacizumab (IVB) (1.25mg/0.05 mL) and intravitreal ranibizumab (IVR) (0.5mg/0.05mL) for the treatment of myopic choroidal neovascularisation (CNV). The study was designed to detect a difference in the best corrected visual acuity (BCVA) of 10 Early Treatment Diabetic Retinopathy Study (EDTRS) letters with a standard deviation (SD) of two lines. Forty-four patients were required (22 in each arm per group) to detect this difference with 90% power, two-sided with 5% significance level). To allow for dropping out during the total 18 month follow-up period, a minimum of 50 patients were recruited and a p value at <0.05 was considered significant. Fifty-five subjects were finally enrolled and 27 received IVB vs. 28 patients who were randomised to IVR. The inclusion criteria were: 1) myopic of sp > -6.0 or > axial length 26.5mm if there were retinal abnormalities present but sp < -6.0, 2) treatment of naïve subfoveal myopic CNV, 3) base line BCVA 20/32 – 20/400 inclusive. The exclusion criteria were: 1) intraocular surgery within six months of the day of the injection, 2) ocular disease that could compromise vision, 3) ocular hypertension, glaucoma and 4) uncontrolled systemic hypertension, peripheral vascular disease history of thromboembolism, ischaemic heart disease or stroke. Retreatments were performed on a pro re nata basis if monthly examinations up to 18 months confirmed any of the following: 1) subretinal, intraretinal fluid on the optical coherence tomography (OCT), 2) leakage on the fundus flourescein angiography (FFA), 3) new haemorrhage on fundoscopy. Primary outcome measures were the changes in the mean BCVA and the proportion of eyes improving in BCVA by >1 and >3 lines at the 18 month examination. Secondary outome measures were: 1) changes in the mean central macular thickness (CMT), 2) changes in the mean number of injections and 3) changes in the mean CNV area. At the 18-month final examination the IVB group showed a 1.8 lines improvement and the IVR, 1.7 lines. The difference in the final BCVA was not statistically significant. A three-line gain was observed in 30% of the IVR group and 44% in the IVB group. However, the IVR group achieved a faster CMT improvement with a significantly lower number of injections required (2.5) compared to IVB (4.7 p<0.001). This study claims to be the first one to compare IVB and IVR for CNV in pathologic myopia in the medium term (18 months) and limitations include few patients and the shortness of the follow-up period. Nevertheless, it forms the basis for future randomised clinical trials to investigate the role of anti-VEGFs in the management of myopic CNV.

Reference

Intravitreal ranibizumab versus bevacizumab for the treatment of myopic choroidal neovascularisation.
Iacono P, Parodi MB, Papayannis A, et al.
RETINA
2012;32(8):1539-45.

Strabismus

Comparison of occlusive patches
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors investigated the comfort of wear of patches in correlation with compliance using the occlusion dose monitor and a questionnaire. They also assessed the material properties of the different brands: 3M opticlude, Master-Aid orthopad, Lohmann-Rauscher pro-ophta and BSM Medical coverlet. Twenty-two children completed the trial. The results showed large differences in the patch properties. Breathing property of all patches was minimal at room temperature. Maximum force required to remove a patch from the skin was least with the L-R and most with BSM, suggesting that some brands may be more suitable for longer duration of patching. No patch eliminated 100% of light.

Reference

Comfort of wear and material properties of eye patches for amblyopia treatment and the influence on compliance.
Roefs AMJ, Tijam AM, Looman CWN, et al.
STRABISMUS
2012;20(1):3-10.

Strabismus

Fusional divergence in intermittent exotropia
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors evaluated fusional divergence in children with intermittent exotropia and examined correlations with exo deviaton control score, angle of deviation and fusional covergence. They compared fusional divergence in children with intermittent exotropia and visually normal children. Thirty-eight formed the visually normal non-strabismus cohort and 32 subjects had intermittent exotropia. In intermittent exotropia, fusional near divergence break points showed a bimodal distribution, with nearly half showing subnormal divergence break point and distance control score. The near divergence break point and near convergence break point showed a moderate correlation, while distance divergence break point and distance convergence break point showed a strong correlation.

Reference

Assessing divergence in children with intermittent exotropia.
Liebermann L, Hatt SR, Leske DA, et al.
STRABISMUS
2012;20(1):11-6.

Strabismus

Induced motion sickness in vertical phorias
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The goal was to evaluate the relationship between heterophoria and the susceptibility to visually induced motion sickness in a nonclinical sample of subjects. Susceptibility to motion sickness was evaluated during full-field rotation of the visual scene with respect to the stationary observer. Subjects with vertical heterophoria ≥0.75PD exhibited significantly more severe symptoms of motion sickness when exposed to full field visual motion. The results, however, suggest that the presence of a vertical heterophoria and susceptibility to visually induced motion sickness may not be causally related.

Reference

Vertical heterophoria and susceptibility to visually induced motion sickness.
Jackson DN, Bedell HE.
STRABISMUS
2012;20(1):17-23.

Strabismus

Pathogenesis and treatment for post vitreoretinal strabismus
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

This paper explores the incidence, pathology and treatment options. The pathogenesis includes mechanical factors, extraocular muscle insertional changes or damage, myotoxicity from local anaesthetic injection, sensory factors and foveal misalignment. Nonsurgical management included monocular occlusion, prisms and botulinum toxin. Surgical management included removal of retinal explants, removal of scar tissue and extraocular muscle surgery.

Reference

Post-vitreoretinal strabismus surgery – a review.
Chaudhry NL, Durnian JM.
STRABISMUS
2012;20(1):26-30.

Strabismus

Superior rectus BT injection
Reviewed by: Fiona Rowe
Dec/Jan 2013 (Vol 19 No 4)
 

The authors aimed to study the indications, outcomes and complications of superior rectus botulinum toxin (BT) injection. Eight patients received a total of 20 BT injections to the superior rectus muscle. Indications included residual hypertropia due to surgery for retinal detachment, surgery for thyroid eye disease and surgery with full tendon lateral transposition for sixth nerve palsy. The main complication of ptosis occurred in seven patients. The authors conclude this is a viable treatment option with long lasting reduction in deviation of approximately 10PD after two to three injections.

Reference

BT injection into the superior rectus for treatment of strabismus.
Dawson E, Ali N, Lee JP.
STRABISMUS
2012;20(1):24-5.

Acta Ophthalmologica

Optical coherence tomography for glaucoma screening
Reviewed by: Nana Theodorou
Oct/Nov 2012 (Vol 19 No 3)
 

Time-domain optical coherence tomography (OCT) is a two dimensional imaging method which produces cross sectional retinal images. Recently new OCT instruments using spectral-domain technology have been developed. They provide axial resolution and increases in scanning speed of more than a factor of 50. For glaucoma diagnosis the spectral-domain Cirrus OCT extracts peripappilary scans. The aim of this article was to evaluate the diagnostic performance in terms of sensitivity, specificity and predictive values of time-domain Stratus and spectral-domain Cirrus OCT for use in population or selective glaucoma screening. A random sample of 307 participants living in two rural areas in Sweden and a random sample of 394 clinical glaucoma patients were selected for participation. OCT retinal fibre layer thickness analyses for average thickness, quadrant and clock-hour sectors were compared with normative significance limits available in the instruments. The population based sample included 129 healthy and nine glaucoma patients and the sample of glaucoma patients included 128 patients. Sensitivity increased considerably when relying on the quadrant sector parameter while specificity decreased only marginally. In conclusion, Stratus with high specificity and positive predictive values seemed the best for screening purposes while Cirrus with high sensitivity was the better choice for early detection.

Reference

Performance of time-domain and spectral-domain optical coherence tomography for glaucoma screening.
Bengtsson B, Andersson S, Heijl A.
ACTA OPHTHALMOLOGICA
2012;90:310-5.
Performance of time-domain and spectral-domain optical coherence tomography for glaucoma screening.
Bengtsson B, Andersson S, Heijl A.
ACTA OPHTHALMOLOGICA
2012;90:310-5.

British Journal Of Ophthalmology

Childhood blepharokeratoconjunctivitis
Reviewed by: Jonathan Chan
Oct/Nov 2012 (Vol 19 No 3)
 

This is a retrospective review of all patients with the diagnosis of blepharokeratoconjunctivitis (BKC) between September 2002 to August 2008 at the tertiary referral centre in Birmingham. The disease was graded according to the activity and residual damage from the condition. The lid or conjunctival swabs were taken before starting the therapy comprising lid hygiene, topical / systemic antibiotics (tetracycline or erythromycin), intensive topical steroid eye drops and systemic immunosuppression with azathioprine or mycophenolate. Ten white patients (20 eyes) with a medium age 15.2 (range six to 27) years were identified. Improvement in disease activity was achieved in all cases. Intensive topical steroid regime was used, resulting in disease control in 10 out of 16 severely involved eyes. The remaining six affected eyes (three patients), with progressive corneal damage required systemic immunosuppression. Remission was achieved within three months of commencing systemic immunosupression; azathioprine in four eyes (two patients with one patient requiring a short induction course of oral Prednisolone) and mycophenolate mofetil in two eyes (one patient). No adverse effects were experienced during the follow-up period of 4.4 (range 1.7-6.6) years. Corneal perforations occurred in three eyes (two patients). The median duration of symptoms prior to presentation was 4.3 years. Fourteen eyes (nine patients) showed 360 degree peripheral corneal vascularisation, associated with involvement of the visual axis in 10 eyes (six patients). The authors conclude that a severe type of BKC in white Caucasian young adults required early referral to specialist centres, to facilitate aggressive treatment and limit permanent ocular damage and visual loss.

Reference

Childhood blepharokeratoconjunctivitis: characterising a severe phenotype in white adolescents.
Hamada S, Khan I, Dennistone AK, Rauz S.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96:949-55.
Childhood blepharokeratoconjunctivitis: characterising a severe phenotype in white adolescents.
Hamada S, Khan I, Dennistone AK, Rauz S.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96:949-55.

Clinical and Experimental Ophthalmology

Effectiveness of autologous cultured LSC grafts in LSCD due to chemical burns
Reviewed by: Kwesi Amissah-Arthur
Oct/Nov 2012 (Vol 19 No 3)
 

This paper by Marchini et al. investigates the long-term effectiveness of unilateral limbal stem cell deficiency (LSCD) treated by autologous ex vivo cultured stem cell grafts. This prospective non-comparative interventional case series looked at this particular approach with the aim of replenishing the stem cell population in LSCD. Sixteen eyes from 16 patients with an age range of 23-71 years (median: 47.5 years) were observed. They all had unilateral LSCD secondary to chemical burns. The event-to-intervention time varied from one to 50 years (median: 25 years). Autologous stem cells were isolated from a biopsy specimen (1-2mm2) taken from the healthy contralateral eye of each patient under topical anaesthesia. These were cultivated onto feeder layers of lethally irradiated murine 3T3 cells for seven to ten days as previously described. When the cells were sub-confluent, they were placed on a circular modified fibrin glue disc. A peripheral ring of fibrin was trimmed off 24 hours prior to transplantation and used as a quality control assay. The percentage of corneal and conjunctival epithelial cells was evaluated using antibodies against Keratin 3 (K3), Keratin 19 (K19) and a p63 marker. The limbal stem cell (LSC) sheets were grafted by performing a 360-degree peritomy with dissection of the fibrovascular pannus and cauterisation of blood vessels. The autologous cultured LSC grown on the fibrin disc were placed on the denuded corneal stroma and the conjunctiva sutured over the peripheral fibrin sheet. The eyelids were then kept closed with the aid of steri-strips. The procedure was performed under retrobulbar anaesthesia. Clinical results and outcomes were evaluated from the 12th month post intervention. Follow-up ranged from 12 to 50 months. Disappearance or amelioration of discomfort symptoms and recovery of a stable, transparent and avascular epithelium onto the 8mm central corneal surface was defined as an overall success. The treatment was considered as partially successful in cases of re-appearance of conjunctival ingrowths in some sectors of the central cornea and irregularity of the corneal surface. Failure was when the postoperative clinical conditions resembled the preoperative ones. Evaluation at 12 months showed that after LSC transplantation the outcome was successful in 10 patients (62.6%), partially successful in three (18.7%) and unsuccessful in three (18.7%). Three patients were treated twice and penetrating keratoplasty was performed in seven patients. For two patients, regeneration of the corneal epithelium was confirmed by molecular marker (p63, cytokeratin 3, 12 and 19, mucin 1) analysis. No adverse events occurred in the donor eyes, but there were cases of fungal keratitis in two of the grafted eyes. There have previously been concerns about the use of xenobiotic culture materials including the transmission of known or unknown pathogens to the transplant recipient. The authors state that their data suggests the murine contaminant within the graft is probably too low to lead to any immune responses. However, they state they cannot exclude that surgical procedures may have caused some degree of inflammation and that there is an association between inflammation and LSC graft failure. The journal’s editorial on the work by Marchini et al states that: “[this work] advances our knowledge in this sphere. Indeed, in spite of the uncertainties, the transplantation of cultured limbal epithelium continues to be a promising treatment modality in eyes sustaining severe chemical injury with an otherwise extremely bleak outlook. Unfortunately, at the present time, the relative rarity of the condition coupled with the treatment diversity found in the literature make it difficult to draw definitive conclusions regarding the indications and outcomes of therapy.”

Reference

Long-term effectiveness of autologous cultured limbal stem cell grafts in patients with limbal stem cell deficiency due to chemical burns.
Marchini G, Pedrotti E, Pedrotti M, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(3):255-67.
Long-term effectiveness of autologous cultured limbal stem cell grafts in patients with limbal stem cell deficiency due to chemical burns.
Marchini G, Pedrotti E, Pedrotti M, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(3):255-67.

Cornea

Risk of PED following PKP
Reviewed by: Sharmina Khan
Oct/Nov 2012 (Vol 19 No 3)
 

Retrospective review of 11 cases of penetrating keratoplasty (PKP) and the risk factors for persistent epithelial defects (PED). Most cases following PKP result in rapid epithelialisation. The neurotrophic state following corneal denervation after a PKP results in a reduction in: (i) reflex stimulation of the parasympathetic branch of the facial nerve resulting in tear secretion, and (ii) reflex stimulation of motor branch of facial nerve that responds with eyelid blinking. This results in: (i) aqueous deficient dry eye, and (ii) increased desiccation due to prolonged ‘exposure’. A disproportionate lack of symptoms often leads to a delayed diagnosis of PED. In this centre in Florida, USA, the treatment regime pre- and post-PKP was punctual occlusion, artificial tears and 20% autologous serum (autologous serum is no longer readily available in the UK) stepped up with therapeutic contact lens and tarsorraphy. However, despite these measures, all cases developed PED. The majority of cases had reduced blinking and lagophthalmos, five cases had symblepharon. The pre-existing pathology described in all cases had ocular surface disease (atopic keratitis, bullous keratopathy with previous failed graft, previous chemical injury, Stevens-Johnson syndrome, fungal keratitis) and therefore were at high risk of developing PED.

Reference

Ocular surface deficits contributing to persistent epithelial defect after penetrating keratoplasty.
Fu Y, Liu J, Tseng SCG.
CORNEA
2012;31:723-9.
Ocular surface deficits contributing to persistent epithelial defect after penetrating keratoplasty.
Fu Y, Liu J, Tseng SCG.
CORNEA
2012;31:723-9.

Experimental Eye Research

Keratocytes from stem cells: a new beginning?
Reviewed by: Graham Wallace
Oct/Nov 2012 (Vol 19 No 3)
 

A problem with investigating corneal keratocytes in vitro is the fact that in serum-containing medium they lose their dendritic morphology and adopt fibroblast-like features. Mesenchymal stem-cells (MSC) are pluripotent and have the ability to differentiate into several different types of cells. MSC transplanted into the cornea adopt a keratocyte phenotype and improve transparency. Human bone-marrow derived MSC cultured with keratocyte-conditioned medium (KCM) differentiated into cells expressing keratocyte markers and maintained this phenotype while primary keratocytes differentiated into fibroblasts. The morphology and markers of MSC grown on KCM were not seen in basic medium alone therefore the added growth factors and molecules secreted by the cells intrinsically are important. The potential to develop and maintain corneal keratocytes from MSC will aid the investigation of these cells in response to pathogen and chemical challenge and encourage the study of their regenerative capacity.

Reference

Human mesenchymal stem cells differentiate into keratocyte-like cells in keratocyte-conditioned medium. 
Park SH, Kim KW, Chun YS, Kim JC.
EXPERIMENTAL EYE RESEARCH
2012;101:16-26.
Human mesenchymal stem cells differentiate into keratocyte-like cells in keratocyte-conditioned medium. 
Park SH, Kim KW, Chun YS, Kim JC.
EXPERIMENTAL EYE RESEARCH
2012;101:16-26.

Eye

Effect on optic disc parameters following trabeculectomy
Reviewed by: John Brookes
Oct/Nov 2012 (Vol 19 No 3)
 

This prospective interventional study of 17 patients looked at changes in the retinal nerve fibre layer (RNFL) and optic nerve head (ONH) parameters in adults undergoing trabeculectomy. Average and quadrant RNFL thickness measurements, as well as disc, rim and cup areas were measured using the Stratus optical coherence tomography (OCT) within one week before surgery and one week, one month and three months postoperatively. This study stems from the well known phenomenon of optic disc cupping reversal following reduction in intraocular pressure (IOP) in congenital and juvenile glaucoma. This effect has also been reported previously in adults, although studies have had conflicting results. Also, the clinical relevance of optic disc cupping reversal has not been established. The mechanical theory of glaucoma damage postulates that raised IOP can cause a backward bowing of the lamina and, therefore, reduction in IOP should theoretically ease this back bowing. The study included full data from 17 subjects (13 male and four female), with a mean age of 51 years, the majority having primary glaucoma and included one patient with juvenile-onset glaucoma. The mean pre-operative RNFL thickness increased significantly at one week postoperatively but decreased at one and three months to baseline values. Among the optic nerve parameters, the cup area decreased significantly at one week but reverted to preoperative levels by three months. Other optic disc parameters also reverted to preoperative levels by month three. There was also no correlation between percentage change in IOP and change in RFNL and optic disc parameters and no correlation with age. The study complements other studies, which have not shown any long-term change in optic nerve head or NFL parameters following a reduction in IOP. The use of OCT imaging in this study, which gives cross-sectional images of the optic nerve, with higher resolution than heidelberg retinal tomography (HRT), is a strength of the study but there was a relatively small number of patients included and most patients were categorised as ‘advanced glaucoma’. It may be of interest to look at milder degrees of glaucoma, to see whether the stage of the disease influences optic nerve head reversal.

Reference

Effect of trabeculectomy on RNFL thickness and optic disc parameters using optical coherence tomography. 
Raghu N, Pandav SS, Kaushik S, et al.
EYE
2012;26:1131-7.
Effect of trabeculectomy on RNFL thickness and optic disc parameters using optical coherence tomography. 
Raghu N, Pandav SS, Kaushik S, et al.
EYE
2012;26:1131-7.

Journal Of Cataract And Refractive Surgery

Corneal cross-linking without removal of the corneal epithelium?
Reviewed by: Badrul Hussain
Oct/Nov 2012 (Vol 19 No 3)
 

Corneal collagen cross-linking is a newly accepted method for treating progressive keratoconus. It appears to be the first treatment that can stabilise the keratoconic process. A key component on this photochemical process is riboflavin – a hydrophilic compound that cannot easily cross an intact corneal epithelium. Despite the first published clinical studies removing the corneal epithelium prior to corneal riboflavin administration, many clinicians have elected to perform the technique with the epithelium intact or partially disrupted. In this ex-vivo study of 28 rabbit eyes, enhanced riboflavin drops (Ricrolin TE) were applied every three minutes for one hour to 12 corneas (four with intact epithelium, four with superficial scratches and four with central epithelial debridement) and compared to riboflavin drops without enhancers in similarly prepared 12 corneas. A control group of four intact corneas received balanced 0.9% saline only. Riboflavin absorption was assessed by light-transmission spectra using a spectrophotometer. The results indicate that administration of enhanced riboflavin for 60 minutes in the presence of superficial scratches allows sufficient riboflavin absorption to significantly alter its light-transmission spectra. This did not occur with intact corneal epithelium or unenhanced riboflavin in the presence of superficial scratches. The authors acknowledge the limitations of this ex-vivo study of rabbit eyes, but suggest that avoidance of large areas of epithelial debridement in patients offers significant advantages.

Reference

Evaluation of transepithelial stromal riboflavin absorption with enhanced riboflavin solution using spectrophotometry.
Alhamad TA, O'Brart DP, O'Brart NA, Meek KM.
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2012;38(5):884-9. 
Evaluation of transepithelial stromal riboflavin absorption with enhanced riboflavin solution using spectrophotometry.
Alhamad TA, O'Brart DP, O'Brart NA, Meek KM.
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2012;38(5):884-9. 

Journal of Pediatric Ophthalmology and Strabismus

Paediatric open globe injuries
Reviewed by: Fiona Rowe
Oct/Nov 2012 (Vol 19 No 3)
 

The purpose was to characterise the demographics and clinical features of paediatric open globe injuries in an urban population in the US and to compare the observed final visual acuity to the visual acuity predicted by the ocular trauma score (OTS). One hundred and three eye injuries in patients under the age of 20 years were reviewed. The mean age at presentation was 9.7 years. Fifty-five were aged zero to nine years and 45% aged 10-19 years. Seventy-three percent were male. Seventy-nine percent were due to accidents and 10% due to violence, the latter in the older age group. Fifty-four percent had ocular penetration, 34% with rupture, 7% with foreign body and 4% with perforation. Forty-three percent developed cataract. Most injuries were in zone 1. Final visual acuity prognosis correlated strongly with the results predicted by the OTS. Visual prognosis was poor. The zone of injury may relate to visual acuity, risk of retinal detachment and enucleation.

Reference

Twelve-year review of pediatric traumatic open globe injuries in an urban US population.
Lesniak SP, Bauza A, Son JH, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(2):73-9.
Twelve-year review of pediatric traumatic open globe injuries in an urban US population.
Lesniak SP, Bauza A, Son JH, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(2):73-9.

Journal of Pediatric Ophthalmology and Strabismus

Toy gun trauma
Reviewed by: Fiona Rowe
Oct/Nov 2012 (Vol 19 No 3)
 

This paper reviews a series of 32 children who sustained ocular injuries from airsoft toy guns. Eight percent of ocular trauma was due to airsoft guns (32 cases) at a mean age of nine years, of which 87.5% were male. The assailant was known in 75%. Traumatic hyphaema was the presenting feature of 24 patients. Corneal abrasions were noted in 10 cases. Most injuries led to temporary visual loss. Seven had a significant traumatic cataract and permanent visual disability was due to traumatic cataract.

Reference

Pediatric ocular injuries from Airsoft toy guns.
Shazly TA, Al-Hussaini AK.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):54-7.
Pediatric ocular injuries from Airsoft toy guns.
Shazly TA, Al-Hussaini AK.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):54-7.

Journal of Refractive Surgery

Phakic IOL vs. LASIK for myopia between -6.00 and -9.00 D
Reviewed by: Amit Patel
Oct/Nov 2012 (Vol 19 No 3)
 

The authors claim that no consensus exists regarding the choice of treatment for myopia between -6.00 and -9.00 diopters (D). They therefore compared the outcomes of a foldable iris-fixated phakic intraocular lens (PIOL) versus femtosecond laser-assisted LASIK for this group of patients. Forty-six myopic patients were randomised to undergo bilateral Artiflex (Ophtec BV) PIOL implantation or bilateral femtosecond laser-assisted conventional LASIK with the VISX S2 (Abbott Medical Optics). Refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuity, contrast sensitivity, corneal endothelial cell count, rate of retreatment, and complications were compared. At 12 months follow-up, no difference in spherical equivalent refraction (P=.19) or UDVA (P=.28) was noted. CDVA, however, was better in the PIOL group (P<.001). Spherical equivalent refraction was within ±0.50D in 42 (91.3%) LASIK eyes and 41 (89.1%) PIOL eyes (P>.99). The percentage of eyes gaining lines of CDVA was significantly higher in the PIOL group (50.0% vs. 8.7%; P<.001). Contrast sensitivity was better for PIOL eyes at 1.5 cycles per degree (cpd) (P=.03) and 6cpd (P=.008). Mean endothelial cell count decreased by 9.1%±2.0% (P<.001) in the PIOL group. The rate of retreatment was similar (10.9% LASIK vs. 17.4% PIOL, P=.37) and all retreatments were performed after 12 months and not included in the above data. The speed of visual recovery and use of lubricants was similar in the two groups and no serious complications occurred in either group. Overall, the study shows that PIOLs provided better CDVA and contrast sensitivity compared to conventional LASIK at 12 months.

Reference

Foldable iris-fixated phakic intraocular lens vs. femtosecond laser-assisted LASIK for myopia between -6.00 and -9.00 diopters.
Albarrán-Diego C, Muñoz G, Ferrer-Blasco T, et al.
JOURNAL OF REFRACTIVE SURGERY
2012;28(6):380-7.
Foldable iris-fixated phakic intraocular lens vs. femtosecond laser-assisted LASIK for myopia between -6.00 and -9.00 diopters.
Albarrán-Diego C, Muñoz G, Ferrer-Blasco T, et al.
JOURNAL OF REFRACTIVE SURGERY
2012;28(6):380-7.

Journal of Refractive Surgery

Simultaneous collagen cross-linking and topography guided PRK in keratoconus
Reviewed by: Amit Patel
Oct/Nov 2012 (Vol 19 No 3)
 

This study reports the outcomes of 22 eyes with low-grade keratoconus that underwent combined corneal collagen cross-linking (CXL) and topography-guided photorefractive keratectomy (TG-PRK). Inclusion criteria were low-grade keratoconus with evidence of progression, transparent cornea, corrected distance visual acuity (CDVA) 0.8 (decimal) or better, corneal thickness >440µm, and maximum keratometry readings (K-max) <51.00 diopters (D). TG-PRK was performed prior to CXL and the ablation depth limited to achieving ±1.00D of emmetropia and preserving at least 400µm of residual stroma. Outcomes measured included uncorrected visual acuity (UDVA), CDVA, manifest refractive error, manifest and topographic (corneal) astigmatism, patient satisfaction, and efficacy and safety of the treatment. All patients had one year follow-up and statistically significant improvement was noted in all study parameters (P<.01). Patient satisfaction questionnaire showed that 91% were satisfied, 9% were not completely satisfied but believed they improved and none were dissatisfied. Corneal topography demonstrated significant improvement in 55%, improvement in 36%, and minor improvement in 9% of cases. No cases progressed as evidenced by keratometry readings. The study confirms the success of earlier reports of similar treatment regimens and included a subjective element to the outcome assessment. The authors state TG-PRK with CXL is an effective and safe treatment which results in visual and topographic improvements. It is limited by the inclusion of low-grade keratoconus and a relatively short follow-up period.

Reference

Safety and efficacy of simultaneous corneal collagen cross-linking with topography-guided PRK in managing low-grade keratoconus: 1-year follow-up.
Tuwairqi WS, Sinjab MM.
JOURNAL OF REFRACTIVE SURGERY
2012;28(5):341-5.
Safety and efficacy of simultaneous corneal collagen cross-linking with topography-guided PRK in managing low-grade keratoconus: 1-year follow-up.
Tuwairqi WS, Sinjab MM.
JOURNAL OF REFRACTIVE SURGERY
2012;28(5):341-5.

Ophthalmic Genetics

A review of choroideremia
Reviewed by: Nana Theodorou
Oct/Nov 2012 (Vol 19 No 3)
 

This review article concentrates on choroideremia. Choroideremia is an X-linked retinal dystrophy characterised by progressive degeneration of the choriocappilaris, retinal pigment epithelium (RPE) and photoreceptors. Choroideremia is caused by mutations in the Rab Escort Protein 1 gene. The incidence varies between 1:50,000 and 1:100,000. The article is clearly divided into eight main sections. The first two sections describe the clinical features and retinal visual function for affected males and female carriers. The next section on genetics describes previous literature reports on biochemistry and mutations and gene defects. The pathogenesis section details the four proposed hypotheses relating to the degeneration of the retina, RPE and choroid. Two more sections comment on a few reported associated conditions and points to consider during differential diagnosis. The last two sections look at genetic counselling and the options available for the treatment and management of the condition. This review is very well structured and offers a good overview of choroideremia.

Reference

Choroideremia: A review of general findings and pathogenesis.
Coussa RG, Traboulsi EI.
OPHTHALMIC GENETICS
2012;33(2):57-65.
Choroideremia: A review of general findings and pathogenesis.
Coussa RG, Traboulsi EI.
OPHTHALMIC GENETICS
2012;33(2):57-65.

Ophthalmic Genetics

Choroideremia: effect of age on visual acuity
Reviewed by: Nana Theodorou
Oct/Nov 2012 (Vol 19 No 3)
 

The main aim of this study was to employ cross-sectional and longitudinal analysis to characterise the degree and progression of visual acuity loss over time in patients with choroideremia. The corrected visual acuity of 120 affected males and 53 female carriers were collected from 24 studies or case reports on choroideremia published between 1981 and 2010. Fifteen patients from the authors’ clinic were also included. The mean patient age of affected males was 36.6 years. There was significant decrease in logMAR visual acuity per year. There was also a significant difference between visual acuity and age for patients <50 years and those >50 years. The average age of female carriers was 36.4 years. There was no significant correlation between visual acuity and age for female patients. The authors conclude that in affected males with choroideremia, visual acuity decreases very slowly until they reach 50 years of age, then the rate and extent of vision loss becomes significantly higher. Additionally, visual acuity decreases more rapidly as individuals get older. Visual acuity loss in female carriers appeared much milder. This article offers information on the potential progression of the disease relating to visual acuity loss over time

Reference

Choroideremia: Effect of age on visual acuity in patients and female carriers.
Coussa RG, Kim J, Traboulsi EI.
OPHTHALMIC GENETICS
2012;33(2):66-73.
Choroideremia: Effect of age on visual acuity in patients and female carriers.
Coussa RG, Kim J, Traboulsi EI.
OPHTHALMIC GENETICS
2012;33(2):66-73.

Ophthalmic Plastic And Reconstructive Surgery

Stereotactic fractionated radiotherapy for orbital cavernous haemangioma
Reviewed by: Vinod Gauba
Oct/Nov 2012 (Vol 19 No 3)
 

Although symptomatic orbital cavernous haemangioma can be treated successfully with complete surgical excision, the procedure becomes increasingly risky if the lesion involves other local structures such as the ophthalmic artery, orbital apex or orbital fissure. The authors report the results of a retrospective study using fractionated stereotactic radiotherapy (SFRT) on five such cases. A minimum of 20 fractions were used and an average 60% overall tumour shrinkage was noted. No complications to the treatment were noted, suggesting that this could be a useful adjunct to control lesion size and improve visual function in certain cases where complete surgical excision is high risk.

Reference

Stereotacticfractionatedradiotherapyforcavernousvenousmalformations(hemangioma)oftheorbit.
RootmanDB,RootmanJ,GregoryS,etal.
OPHTHALMICPLASTICANDRECONSTRUCTIVESURGERY
2012;28(2):96-102.
Stereotactic fractionated radiotherapy for cavernous venous malformations (hemangioma) of the orbit.
Rootman DB, Rootman J, Gregory S, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2012;28(2):96-102.

Ophthalmic Plastic And Reconstructive Surgery

Topical 0.25% timolol maleate gel to treat cutaneous infantile capillary haemangiomas
Reviewed by: Vinod Gauba
Oct/Nov 2012 (Vol 19 No 3)
 

The authors report the results of a retrospective non-randomised cohort study on patients presenting with nonvision-threatening periocular infantile capillary haemangiomas. Parents were offered to choose between topical 0.25% timolol maleate gel or observation. Masked evaluators studied photographs taken at every visit. Out of 23 children studied 13 received timolol, whilst 10 were observed. In the treated group, a moderate to good response was seen in over 90% of children; whilst in the observed group a moderate to good response was seen in only 10% with a statistically significant difference. In the treated group, it was noted that both superficial and mixed lesions responded well to topical treatment, whilst deep lesions had a poor response. No adverse ocular or systemic reactions were noted and the achieved results were found to be stable over long-term follow-up. The topical delivery of beta-blocker has many potential systemic and logistical advantages over systemic administration. Although larger series are required to further validate this technique, the findings so far are very promising.

Reference

 

A controlled study of topical 0.25% timolol maleate gel for the treatment of cutaneous infantile capillary hemangiomas.
Chambers CB, Katowitz WR, Katowitz JA, Binenbaum G.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2012;28(2):103-6.
A controlled study of topical 0.25% timolol maleate gel for the treatment of cutaneous infantile capillary hemangiomas.
Chambers CB, Katowitz WR, Katowitz JA, Binenbaum G.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2012;28(2):103-6.

Ophthalmic Research

Topical and subconjunctival bevacizumab equally effective as anti-angiogenic agents in corneal neovascularisation
Reviewed by: Uwe Pleyer
Oct/Nov 2012 (Vol 19 No 3)
 

Corneal neovascularisation remains an important complication of infectious, inflammatory or traumatic disorders. Subsequent corneal scarring, oedema and visual impairment often results. Since anti-VEGF agents have been highly successfully applied as treatment in different retina diseases, there is growing interest in the use of topical and subconjunctival anti-VEGF agents for the treatment of corneal neovascularisation. Bevacizumab, as one of the well known anti-VEGF agents, has been chosen for this experimental study. So far, no standard protocol for the mode of application, dose, concentration and frequency has been introduced. Therefore, the authors of this study compared the inhibitory effects of topical and subconjunctival bevacizumab on corneal neovascularisation in a rat model. Using a chemically induced corneal burn, animals were randomised into a control group (topical artificial tear) a subconjunctival bevacizumab injection (1.25 mg in 0.05 ml) at day one, four and seven, and two groups treated with topical bevacizumab drops of four or 12.5mg/ml bevacizumab twice daily. Interestingly, all corneas receiving bevacizumab demonstrated significant (0.01), but not complete inhibition of neoangiogenesis during the 10 day observation period. Both modes of application and both concentrations were equally effective, with no obvious dose related effect. Clinical observation and histopathology did not reveal any undesired effects, e.g. epitheliopathy. This study is in line with previous findings that did not find a difference regarding the mode of application (subconjunctival vs. drops). However, in many studies a dose dependent effect was reported. The authors hypothesise that the application frequency and duration was still not optimal. In addition, other angiogenic growth factors are probably involved and explain that no complete inhibition could be achieved. Taken together, both subconjunctival injection and topical use of bevacizumab have been effective and safe in controlling corneal neovascularisation in a standard corneal burn model

Reference

Topical and subconjunctival bevacizumab for corneal neovascularization in an experimental rat model.
Öner V, Küçükerdönmez C, Akova YA, et al.
OPHTHALMIC RESEARCH
2012;48(3):118-23.
Topical and subconjunctival bevacizumab for corneal neovascularization in an experimental rat model.
Öner V, Küçükerdönmez C, Akova YA, et al.
OPHTHALMIC RESEARCH
2012;48(3):118-23.

Ophthalmology

Bevacizumab for macular oedema in central retinal vein occlusion
Reviewed by: Brian Ang
Oct/Nov 2012 (Vol 19 No 3)
 

The authors report on a prospective, randomised, double-masked clinical trial comparing intravitreal bevacizumab (Avastin) 1.25 mg in 0.05ml versus sham injections in the treatment of central retinal vein occlusion (CRVO) with macular oedema. Inclusion criteria were CRVO of less than six months in duration, optical coherence tomography (OCT) thickness of ≥300µm and best-corrected visual acuity (BCVA) of 20/50 to 20/500. Patients with neovascularisation and previous treatment for CRVO were excluded. Importantly, those with RAPD were not excluded from the trial. Treatment was given every six weeks, giving a total of four treatments over six months. Sixty patients were recruited, with 30 in the treatment arm and 30 in the control arm. At six months, the bevacizumab treated eyes had improved BCVA by a mean of 14.1 ETDRS letters, while the control eyes had lost a mean of 2.0 ETDRS letters. Sixty percent (18/30) of bevacizumab treated eyes had gained ≥15 ETDRS letters compared to only 20% (6/30) of control eyes. The BCVA in the treated group was better at all follow-up time points compared to the control group, but this difference only became statistically significant at 12 weeks. There was a corresponding improvement in OCT retinal thickness, with 86.7% (26/30) in the treated group showing no residual oedema compared to 20% (6/30) in the control group. None of the treated group developed neovascularisation compared to 16.7% (5/30) in the control group. None of the treated group experienced any ocular or systemic complications from the injections. This trial shows that intravitreal bevacizumab is beneficial in macular oedema for CRVO, with results similar to that for ranibizumab (in the previously published CRUISE study) but with a longer interval between treatments. A one-year extension of the study is ongoing, and the results are eagerly awaited.

Reference

Bevacizumab for macular edema in central retinal vein occlusion: a prospective randomized, doubled-masked clinical study.
Epstein DLJ, Algvere PV, von Wendt G, et al.
OPHTHALMOLOGY
2012;119:1184-9.
Bevacizumab for macular edema in central retinal vein occlusion: a prospective randomized, doubled-masked clinical study.
Epstein DLJ, Algvere PV, von Wendt G, et al.
OPHTHALMOLOGY
2012;119:1184-9.

Ophthalmology

CATT study: two-year results
Reviewed by: Brian Ang
Oct/Nov 2012 (Vol 19 No 3)
 

The Comparison of AMD Treatments Trial (CATT) was set up to compare the efficacy of bevacizumab versus ranibizumab, as well as monthly versus as-needed dosing, in the treatment of exudates age-related macular degeneration (AMD). The one year results showed that both bevacizumab and ranibizumab had similar visual acuity results, and that monthly and as-needed dosing of either drug did not affect visual outcomes. Although there was no significant difference in the rates of death and artheriothrombotic events at one year, bevacizumab was associated with more serious adverse events. This paper reports on the two year results of the trial. An important change in treatment regime is that at the one year point, patients who were assigned to monthly treatments were reassigned randomly to either monthly or as-needed treatment, without change to the treatment drug. Patients who were already in the as-needed treatment arm had no change in treatment frequency. In general, there was little change in visual acuity at two years compared to at one year in all treatment groups. However, for those in whom monthly treatments were switched to treatments as needed, there was a decrease in visual acuity (-1.8 letters in the ranibizumab group and -3.6 letters in the bevacizumab group). The ranibizumab treatment was associated with less residual macular fluid but more non-foveal geographic atrophy at two years. Additionally, the bevacizumab as-needed group required on average 1.5 injections more than the ranibizumab as-needed patients. Both ranibizumab and bevacizumab had a similar proportion of deaths and venous thrombotic events at two years, but the higher rates of systemic serious adverse events for bevacizumab seen at one year persisted (39.9% bevacizumab versus 31.7% ranibizumab; P=0.009). Gastrointestinal disorders (haemorrhage, hernia, nausea, vomiting) showed the greatest discrepancy. Overall, the results at two years generally mirror those at one year, demonstrating both bevacizumab and ranibizumab to be effective in improving visual acuity in AMD, but treatment as needed achieved less gain in visual acuity than regular monthly treatment.

Reference

Ranibizumab and bevacizumab for treatment of neovascular age-related macular degeneration.
CATT Research Group.
OPHTHALMOLOGY
2012;119:1388-98.
Ranibizumab and bevacizumab for treatment of neovascular age-related macular degeneration.
CATT Research Group.
OPHTHALMOLOGY
2012;119:1388-98.

Orbit

A review of lateral canthal anatomy
Reviewed by: Konal Saha
Oct/Nov 2012 (Vol 19 No 3)
 

A useful, detailed review of lateral canthal anatomy with description of new findings. The lateral canthal tendon is more accurately described as the lateral canthal band as it has both tendinous and ligamentous components. A lateral orbital thickening lying between the lateral canthal band and orbicularis oculi is described and postulated to slacken with age resulting in lower eyelid descent. Previous descriptions of a lateral palpebral raphe have not been supported, instead a description is made of the orbicularis oculi being continuous around the lateral canthus. A lateral canthal muscle lying within the upper eyelid at the lateral canthus has been identified but its function not elucidated. A band of fibroelastic tissue – the lateral rectus capsulopalpebral fascia (lrCPF) – including the lateral rectus muscle pulley, lateral check ligament and smooth muscle fibres connects the tarsal plate, lateral conjunctival fornix and Whitnall’s tubercle. An interesting link is made between the lrCPF and increased Meibomian gland secretion with lateral eye movement. The presence of the orbitomalar ligament as a firm band originating from the inferior orbital rim extending through the submuscular fat and orbicularis to the skin is supported. Elongation of this structure with age is thought to contribute to midfacial ptosis.

Reference

Lateral canthal anatomy: a review.
Kang H, Takahashi Y, Ichinose A, et al.
ORBIT
2012;31(4):279-84.
Lateral canthal anatomy: a review.
Kang H, Takahashi Y, Ichinose A, et al.
ORBIT
2012;31(4):279-84.

Orbit

Lateral brow descent following upper blepharoplasty
Reviewed by: Konal Saha
Oct/Nov 2012 (Vol 19 No 3)
 

An interesting article providing objective evidence of lateral brow descent following upper blepharoplasty. The authors use angular measurements of the brow position from digital photographs preoperatively and two to four months postoperatively. They found statistically significant changes in brow position relative to canthal positions following upper blepharoplasty. The technique of blepharoplasty surgery is not standardised, generally being tailored to the needs of the patient. The extent of tissue resection combined with brow stability are likely to influence the final position of the brow. Hence, the authors rightly describe needing to address the brow when considering upper blepharoplasty.

Reference

Assessment of eyebrow position before and after upper eyelid blepharoplasty.
Prado RB, Silva-Junior DE, Padovani CR, Schellini SA.
ORBIT
2012;31(4):222-6.
Assessment of eyebrow position before and after upper eyelid blepharoplasty.
Prado RB, Silva-Junior DE, Padovani CR, Schellini SA.
ORBIT
2012;31(4):222-6.

Retina

Causes of unsuccessful ranibizumab treatment in exudative AMD in clinical settings
Reviewed by: This retrospective multicentre (three units in France) analysis of 290 consecutive eyes of three cohorts from three clinical settings without pre-esta
Oct/Nov 2012 (Vol 19 No 3)
 

This retrospective multicentre (three units in France) analysis of 290 consecutive eyes of three cohorts from three clinical settings without pre-established protocols and visit schedules (so called ‘real-world studies’) aimed to identify causes of loss of vision after ranibizumab therapy in patients with exudative age-related macular degeneration (AMD). Analysis of charts and fundus images of patients treated for exudative AMD who received treatment for one year was performed in the three units, analysed by two independent readers. Patients excluded were: 1) patients with diseases other than AMD (e.g. myopic choroidal neovascularisation (CNV), suspected idiopathic polypoidal choroidal vasculopathy (IPCV)), 2) those not examined at 52+/-6 weeks. Twenty-one eyes lost >15 EDTRS letters one year after starting treatment. The proportions of patients from each of the three centres experiencing visual loss were not significantly different (7.24% p=0.26) with a mean visual loss of 27 letters. There was no significant difference between these eyes with regards to age, gender, laterality, type of CNV, number of visits, initial best corrected visual acuity. Visual loss was due to progression of atrophy in eight eyes, fibrosis in five eyes, fibrosis with atrophy in three eyes, severe subretinal haemorrhage in three eyes and retinal pigment epithelium tear in two eyes. The study, despite its limitations, showed that uncommon visual loss may occur in eyes whilst treated for AMD with ranibizumab and is due to the natural course of AMD in most cases.

Reference

Causes of unsuccessful ranibizumab treatment in exudative ARMD in clinical settings. 
Cohen S, Oubraham H, Uzzan J, et al.
RETINA
2012;32(8):1480-5.
Causes of unsuccessful ranibizumab treatment in exudative ARMD in clinical settings. 
Cohen S, Oubraham H, Uzzan J, et al.
RETINA
2012;32(8):1480-5.

Retina

Transconjunctival drainage of serous and haemorrhagic choroidal detachment
Reviewed by: Nikolaos D. Georgakarakos 
Oct/Nov 2012 (Vol 19 No 3)
 

The authors present a series describing a transconjunctival technique for the surgical management of choroidal detachment in eyes with previoius trabeculectomies  with or without conjunctival thinning, that does not require concominant pars plana vitrectomy. The authors explain that instead of placing the sclerostomy in the pars plana, a trochar is inserted 7mm from the limbus away form the uveal tissue with an anteroposterior pressure maintained with an anterior chamber (AC) maintainer. The authors recommend a 20g cannula for haemorrhagic choroidal detachment and 25g for serous. Two patients with haemorrhagic and four patients with serous choroidal detachments were included in this paper with a choroidal detachment of at least 7mm in height for safety purposes given the lengths of the trochars used (6.5 mm for the 25g trochar and 9.5 mm for the 20g trochar). The trochar / cannula system was inserted in the suprachoroidal space with a bevelled incision introduced at an angle to avoid chrodoidal and / or retinal trauma. The authors reported that all patients recovered at least ambulatory vision without complications within one month and intraocular pressure (IOP) in all eyes was at least 10mmHg by one week postop. Difficulties encountered include poor access to the AC with the maintainer if the AC is collapsed and in this case a 23g self-retaining infusion could be used instead. Additionally, a second instrument should be used to fixate the globe when inserting the trochars to prevent accidental choroidal or retinal damage. Indirect ophthalmoloscopy or intraoperative B scans should be performed to ensure no complications have occurred. The number of cases is small to draw definite conclusions and larger numbers are required to test its safety, potential complications and efficacy.

Reference

Transconjunctival drainage of serous and haemorrhagic choroidal detachment. 
Rezende FA, Kickinger MC, Li G, et al.
RETINA
2012;32(2):242-9.
Transconjunctival drainage of serous and haemorrhagic choroidal detachment. 
Rezende FA, Kickinger MC, Li G, et al.
RETINA
2012;32(2):242-9.

Strabismus

Review of cyclovertical eye movement disorders
Reviewed by: Fiona Rowe
Oct/Nov 2012 (Vol 19 No 3)
 

This review article centred on dissociated vertical deviation (DVD) and see-saw nystagmus. The authors propose a hypothesis on a neural mechanism for these conditions. The interstitial nucleus of Cajal appears to receive projects both from rostral saccadic and vergence pathways through the superior colliculus, omnipause neurons and rostral interstitial nucleus of the medial longitudinal fasciculus (MLF) and from the vestibular otolith pathways. Vertical dissociation in DVD and see-saw nystagmus may result from a failure of the commissure of the superior colliculus to tie together the bilateral monocular eye movement commands.

Reference

A neural model for cyclovertical eye movements and their disorders.
Ten Tusscher MPM.
STRABISMUS
2011;19(4):162-5.
A neural model for cyclovertical eye movements and their disorders.
Ten Tusscher MPM.
STRABISMUS
2011;19(4):162-5.

American Journal of Ophthalmology

Surgical results of triple-DMEK
Reviewed by: KC Madhusudhana
Aug/Sep 2012 (Vol 19 No 2)
 

Descemet membrane endothelial keratoplasty (DMEK) is a relatively new technique involving transplantation of the isolated endothelium–Descemet membrane layer without adherent corneal stroma. Currently there is paucity of data on the results of combined DMEK and cataract surgery (triple-DMEK procedure). The triple procedure has obvious advantages of faster visual rehabilitation and no further endothelial damage induced by sequential cataract surgery. In this retrospective study, the authors have evaluated the results of triple-DMEK, including postoperative best-corrected visual acuity (BCVA), refractive outcome, endothelial cell density (ECD), central corneal thickness (CCT), and detachment rate within a follow-up of six months (N=61 eyes of 56 patients). BCVA increased from 0.6 logMAR preoperatively to 0.19 logMAR at six months postoperatively (P≤0.05). ECD of donor corneas decreased from 2573 cells/mm2 to 1550 cells/mm2 after six months (P≤0.05). CCT decreased from 651µm to 521µm after six months (P≤0.05). 54.5% of eyes were within 1D of emmetropia and 77.3% were within 2D of emmetropia at six months. Refractive cylinder was −0.9±1.0D preoperatively and −1.5±1.0D at six months. Optimised spherical results were achieved by selecting IOLs based on a hyperopic shift of −0.75D. The authors conclude that the improvement in BCVA after triple-DMEK (within the first six months) is comparable to that in sole DMEK and that the addition of cataract surgery to

Reference

Descemet membrane endothelial keratoplasty combined with phacoemulsification and intraocular lens implantation: advanced triple procedure.
Laaser K, Bachmann BO, Horn F, et al. 
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;154(1):47-55.e2.
Descemet membrane endothelial keratoplasty combined with phacoemulsification and intraocular lens implantation: advanced triple procedure.
Laaser K, Bachmann BO, Horn F, et al. 
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;154(1):47-55.e2.

American Journal of Ophthalmology

Surgical results of triple-DMEK
Reviewed by: KC Madhusudhana
Aug/Sep 2012 (Vol 19 No 2)
 

Descemet membrane endothelial keratoplasty (DMEK) is a relatively new technique involving transplantation of the isolated endothelium–Descemet membrane layer without adherent corneal stroma. Currently there is paucity of data on the results of combined DMEK and cataract surgery (triple-DMEK procedure). The triple procedure has obvious advantages of faster visual rehabilitation and no further endothelial damage induced by sequential cataract surgery. In this retrospective study, the authors have evaluated the results of triple-DMEK, including postoperative best-corrected visual acuity (BCVA), refractive outcome, endothelial cell density (ECD), central corneal thickness (CCT), and detachment rate within a follow-up of six months (N=61 eyes of 56 patients). BCVA increased from 0.6 logMAR preoperatively to 0.19 logMAR at six months postoperatively (P≤0.05). ECD of donor corneas decreased from 2573 cells/mm2 to 1550 cells/mm2 after six months (P≤0.05). CCT decreased from 651µm to 521µm after six months (P≤0.05). 54.5% of eyes were within 1D of emmetropia and 77.3% were within 2D of emmetropia at six months. Refractive cylinder was −0.9±1.0D preoperatively and −1.5±1.0D at six months. Optimised spherical results were achieved by selecting IOLs based on a hyperopic shift of −0.75D. The authors conclude that the improvement in BCVA after triple-DMEK (within the first six months) is comparable to that in sole DMEK and that the addition of cataract surgery to

Reference

Descemet membrane endothelial keratoplasty combined with phacoemulsification and intraocular lens implantation: advanced triple procedure.
Laaser K, Bachmann BO, Horn F, et al. 
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;154(1):47-55.e2.
Descemet membrane endothelial keratoplasty combined with phacoemulsification and intraocular lens implantation: advanced triple procedure.
Laaser K, Bachmann BO, Horn F, et al. 
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;154(1):47-55.e2.

American Journal of Ophthalmology

Accuracy of IOL power calculation formulae in children
Reviewed by: KC Madhusudhana
Aug/Sep 2012 (Vol 19 No 2)
 

The paediatric cataract surgeons face a unique challenge of uncertainty regarding intraocular lens (IOL) power calculation. Paediatric eyes undergo rapid elongation in axial length resulting in a myopic shift postoperatively, if an emmetropic power IOL is implanted. Although undercorrection of the IOL power is routinely carried out, the accuracy of the final refractive outcome depends on the precision of the IOL power calculation. Apart from various factors influencing the prediction error in IOL power in children, the current formulae used for calculating IOL power may not be accurate in children with smaller eyes. In this retrospective study, the authors have assessed the accuracy of IOL power calculation formulae in children aged up to two years. The study comprised of 128 eyes of 84 children with congenital cataract undergoing primary IOL implantation (mean age = 11.7 months). Data were analysed for prediction error using the four commonly used IOL power calculation formulae. The absolute prediction error with each of the formulae was calculated and the formula that gave least variability and the best prediction error was determined. The prediction error was found to be 2.27±1.69D with SRK II, 3.23±2.24D with SRK T, 3.62±2.42D with Holladay and 4.61±3.12D with Hoffer Q. The percentage of eyes with absolute prediction error within 0.5D was 21.1% with SRK II, 6.3% with SRK T, 9.4% with Holladay and 3.9% with Hoffer Q. The absolute prediction error with SRK II formula was significantly better than with other formulae (P<0.001). Prediction error with SRK II formula was not affected by factors such as age, keratometry and axial length. Axial length influenced the absolute prediction error with Holladay (P=0.05) and Hoffer Q formulae (P=0.002). Mean keratometry influenced prediction error with SRK T formula. The authors conclude that, although all IOL power calculation formulae tend to have a low accuracy in children up to two years, SRK II formula was the most predictable in this study with an accuracy of 50% for a prediction error of 1D.

Reference

Accuracy of intraocular lens power calculation formulae in children less than two years. 
Kekunnaya R, Gupta A, Sachdeva V, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;154(1):13-9.e2.
Accuracy of intraocular lens power calculation formulae in children less than two years. 
Kekunnaya R, Gupta A, Sachdeva V, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;154(1):13-9.e2.

British Journal of Ophthalmology

Endophthalmitis following IVI or cataract surgery
Reviewed by: Jonathan Chan
Aug/Sep 2012 (Vol 19 No 2)
 

This is a preparation based retrospective study of patients with acute endophthalmitis following either cataract surgery or intravitreal injections (IVI) presenting to a tertiary referral centre in Australia between the period of 2007 and 2010. The mean outcome measures are: 1) identification of the causative organism; 2) time to presentation; 3) odds of improvement in visual acuity (VA) following treatment; 4) odds of final VA of counting fingers (CF) or less and 5) odds of enucleation. All patients underwent a standard trans-pars plana vitreous ‘tap and inject’ protocol at presentation. A 0.2ml vitreous sample was taken for microbiological assessment, following which 1mg of vancomycin in 0.1ml and 2.25mg of ceftazidime in 0.1ml were injected intravitreally. All cases had documented symptoms and signs consistent with endophthalmitis. One or more vitreoretinal specialists confirmed the diagnosis of presumed microbial endophthalmitis in all cases. A total 101 patients were recruited in the study, 38 were culture negative and 63 were culture positive: the causative organisms in the culture-positive cases in the post cataract group were staphylococcus epidermidis at 35.42%; staph aureus 8.33%; streptococcus 6.25%; other gram positive cocci 6.25%, other gram negative rods 6.25%. In the post intravitreal injection group; staph epidermidis 26.41% and staph aureus was 5.66%, streptococcus was 24.53%, other gram-positive cocci 1.89% and in the other gram negative rods group was 3.77%. Endophthalmitis following IVI had increased likelihood of a final visual acuity of counting fingers or less (OR=6.0; p<0.01), decreased likelihood of any improvement in acuity following treatment (OR=0.13; p<0.01) and an increased likelihood of presenting within a week of the procedure (OR=3.93; p<0.01). Endophthalmitis caused by streptococcus infection was associated with increased likelihood of a final VA of CF or less (OR=10.2; p<0.01), decreased likelihood of any improvement in acuity following treatment (OR=0.06; p<0.01) and increased likelihood of enucleation (OR=17.11; p<0.01). The authors concluded that endophthalmitis following IVI presents earlier, and is associated with significantly worse visual outcomes (increased likelihood of VA≤ counting fingers; decreased likelihood of any improvement in VA following treatment) and is associated with an increased frequency of streptococcus spp infection when compared with endophthalmitis following cataract surgery.

Reference

Endophthalmitis following intravitreal injection versus endophthalmitis following cataract surgery: clinical features, causative organisms and post-treatment outcomes.
Simunovic MP, Rush RB, Hunyor AP, Chang AA.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(6):862-6. 

British Journal of Ophthalmology

Mooren’s ulcer in children
Reviewed by: Jonathan Chan
Aug/Sep 2012 (Vol 19 No 2)
 

This is a retrorespective review of all patients with Mooren’s ulcer under the age of 18, presenting at every single eye centre in India between 1987 and 2010. Diagnosis of the Mooren’s ulcer was based on the characteristic clinical features of peripheral corneal ulceration with overhanging margins, circumferential spread with cellular infiltration at the advancing edge, no scleral involvement and absence of any systemic disease. It was confirmed by relevant systemic investigations including the normal complete blood count, a normal erythrocyte sedimentation rate and negative markers of immunological disorders that can result in a similar clinical picture. There were 14 eyes of 11 children (seven males and four females, with an average age of 12.45±2.25 years at presentation) and eight unilateral and three bilateral cases in the study. The severity of the corneal involvement was expressed in terms of the number of clock hours of peripheral corneal involvement and amount of stromal thinning. Severe cases were defined as unilateral or bilateral cases with more than two quadrants of peripheral corneal involvement and / or more than 90% thinning or perforation and rapid progression as evidence from the history or clinical course of the disease. The medical treatment includes intensive topical prednisolone acetate 1% eye drops and oral prednisolone therapy (1mg/kg of body weight once daily and tapered slowly depending on the response. Immunosuppressant agents include methotrexate orally (7.5-12.5mg/week) along with oral folic acid (5mg/day for five days a week) was used as a steroid sparing agent whenever indicated. Surgical therapy including tissue adhesive and bandage contact lens application, amniotic membrane transplantation, optical penetrating keratoplasty and limbal stem cell transplantation was performed in most eyes as part of the primary management or later during the disease course. The mean follow-up period was 69.1 weeks. Ten eyes healed successfully and one developed descemetocele. Three eyes developed secondary infection (infective keratitis), two of which had infection following keratoplasty. Streptococcus pneumonia was identified as the causative organism; one of which ultimately became phthisical. Mean (standard deviation) visual acuity at presentation was 0.741 (0.86) logMar units, while at the last visit it was 0.716 (0.68) logMAR units. The authors concluded that Mooren’s ulcer in children, although is a rare entity, is of clinical significance due to its severe and aggressive nature and sight-threatening complications. Good anatomical results and stable visual function can be achieved with aggressive treatment involving a team multi-disciplinary approach. Immunosuppression is important to the success of the therapy, especially if systemic immunosuppression is required in cases of severe disease. All these children require close monitoring by the paediatrician and immunologist during the treatment of the immunosuppression and monitoring of side-effects of the systemic therapy.

Reference

Mooren’s ulcer in children.
Mathur A, Ashar J, Sangwan V.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(6):796-800. 
Mooren’s ulcer in children.
Mathur A, Ashar J, Sangwan V.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(6):796-800. 

Clinical and Experimental Ophthalmology

Descemet’s membrane substrate from human donor lens anterior capsule
Reviewed by: Kwesi Amissah-Arthur
Aug/Sep 2012 (Vol 19 No 2)
 

There have been several changes in corneal transplant surgery over the last decade, chief amongst these changes has been the use of corneal lamellar techniques in corneal transplant surgery. Several authors have stated that the ability to perform posterior lamellar keratoplasty with techniques such as Descemet’s stripping automated endothelial keratoplasty (DSAEK) and Descemet’s membrane endothelial keratoplasty (DMEK) has made visual rehabilitation quicker and safer. This laboratory based study aimed to assess whether human anterior lens capsule (AC) could serve as a carrier for human corneal endothelial cells (HCE) in vitro, therefore acting as a tissue engineered descemet’s membrane (DM), which could be used in future DMEK surgery. The anterior lens capsules of 30 corneal donors were retrieved. Human corneal endothelial cells were recovered from the remaining scleral rims of 15 donor corneas used for penetrating keratoplasty. The HCE cells were sorted into three groups. The first group consisted of 10 samples in which the endothelial cells were grown on anterior lens capsule. The second group consisted of HCE cells grown on a collagen membrane (Resorba). The third group consisted of endothelial cells that grew on 10 polystyrene culture plates (Nunc). The substrates were evaluated at one, four, seven and fourteen days. Parameters looked at included; cell density, morphology and adherence of the cell-capsule complex, microscopy using a phase-contrast microscope and scanning electron microscope. Histology and immuno-histochemistry to assess cell viability and expression of zonula occludens-1, Na+/K+-adenosine triphosphatase, tissue transglutaminase and vimentin was performed. All three groups displayed typical hexagonal morphology of endothelial cells with a characteristic endothelial sheet spread over the total area at day 14. The mean cell density of group one (AC) was 2455.4±283.8 cells/mm2, which was comparable with the cell density of group three (polystyrene), 2506.7±303.4 cells/mm2. The mean cell density of group two (collagen membrane) at day 14 was 2071.5±324.8 cells/mm2. No statistically significant difference was found between the cell densities of the three groups. Cell viability was found to be superior to 95% in all three groups. Immuno-histochemical staining of HCE cells cultivated on anterior lens capsule revealed the presence of zonula occludens-1, Na+/K+-adenosine triphosphatase, tissue transglutaminase and vimentin. This would suggest that AC cultivated HCE cells were well differentiated and presumable functional in vivo. Electron microscopy confirmed the adherence and monolayer growth of the endothelial cells.  There have been other studies that have previously expanded HCEs on other substrates such as human amniotic membrane, laminin, biomaterials and denuded descemet’s membrane. The authors of this study justify the use of the anterior capsule because of its excellent optical and mechanical properties, as well as its similarity to descemet’s membrane. They however do concede that a lot of work has to be done to examine the nutrient diffusion and flow rate of the cell capsule complex as well as assessing if stromal dehydration and corneal transparency can be maintained. The thought of using bioengineered tissue for lamellar corneal transplant surgery is very exciting, especially given the shortage of donor corneas in several countries.

Reference

Descemet’s membrane substrate from human donor lens anterior capsule.
Kopsachilis N, Tsinopoulos I, Tourtas T, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(2):187-94.
Descemet’s membrane substrate from human donor lens anterior capsule.
Kopsachilis N, Tsinopoulos I, Tourtas T, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(2):187-94.

Clinical and Experimental Ophthalmology

Prevalence of OCT-diagnosed postoperative CMO following uncomplicated phacoemulsification cataract surgery
Reviewed by: Kwesi Amissah-Arthur
Aug/Sep 2012 (Vol 19 No 2)
 

Phacoemulsification surgery with implantation of posterior chamber intraocular lenses has improved the incidence of post cataract cystoid macular oedema (CMO) tremendously. However, CMO still remains one of the main causes of unfavourable visual outcome following uncomplicated cataract surgery. The incidence of subclinical CMO according to Vukicevic et al. is uncertain, and the long-term effect this has on visual acuity and retinal structure has not been reported. Fundus fluorescein angiography (FFA) has been the ‘gold standard’ for diagnosing subclinical cystoid macular oedema; however, non-invasive cross-sectional imaging of the retina with optical coherence tomography (OCT) may be equally effective at detecting the condition and offers the ability to quantify and repeat results over time. This prospective consecutive series of 92 patients and 112 eyes undergoing cataract surgery had their macular thickness determined using time domain OCT preoperatively and after surgery at one week, four weeks and six months. The age range of participants was 40 to 90 years (mean 76.18). The postoperative medication regime involved the use of prednefrin forte and chloramphenicol drops instilled four times daily for the first week and then tapered over three weeks. Participants with intraoperative complications (two patients) and with incomplete data (10 patients) were removed from the study. As such, only 100 eyes of 80 patients were analysed. OCT scans were acquired using the fast macular scan protocol of the Carl Zeiss Stratus machine. A report was generated to measure the central foveal thickness (CTF). CMO was present in 5% of eyes (five out of 100). Of these, two participants complained of decreased postoperative visual acuity whilst the other three did not. None of the five patients had predisposing factors to CMO. Macular thickness increased after surgery and central foveal thickness increased by almost 7% but returned to preoperative levels after six months. Patients who developed postoperative CMO appeared to have significantly thicker CFT of approximately 5% compared with those that did not. The authors acknowledge the limitations of using time-domain OCT as opposed to spectral-domain OCT and wonder whether there could have been smaller morphological changes at the macular which were not detected. They also touch on the difference between FFA and OCT diagnosis of CMO. They suspect that FFA based studies give a higher incidence of OCT as there might not be structural changes of the macular in patients who might have some break down of the blood retinal barrier as evidenced by angiographic leakage. The definition of postoperative CMO on OCT scan has been a sticking point as different studies use different criteria, some qualitative and other quantitative to define CMO on OCT. The finding by this study that participants who went on to develop post cataract surgery CMO had a preoperative CFT that was 5% higher needs further investigation as there might be scope to risk stratify patients prior to cataract surgery if this finding was corroborated.

Reference

Prevalence of optical coherence tomography-diagnosed postoperative cystoid macular oedema in patients following uncomplicated phaco-emulsification cataract surgery.
Vukicevic M, Gin T, Al-Qureshi S.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(3):282-7.
Prevalence of optical coherence tomography-diagnosed postoperative cystoid macular oedema in patients following uncomplicated phaco-emulsification cataract surgery.
Vukicevic M, Gin T, Al-Qureshi S.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(3):282-7.

Cornea

Efficacy of combined 0.05% cyclosporine and 1% methylprednisolone treatment in chronic dry eye
Reviewed by: Sharmina Khan
Aug/Sep 2012 (Vol 19 No 2)
 

Tear hyperosmolarity in dry eye is associated with ocular surface inflammation. In severe dry eye, topical lubricants and punctual plugs are often not enough to alleviate symptoms. Topical corticosteroids are used to step up treatment. Topical methylprednisolone 1% (MP) is not widely used and has been reported as pulse treatment in severe dry eye associated with keratoconjunctivitis sicca (Hong S et al. 2007 and Marsh P et al. 1999). Cyclosporine 0.05% (CsA) has been widely available in US and more recently in UK as Restasis. This study compared the efficacy of topical cyclosporine 0.005% plus topical methylprednisolone 1% (Group 1, n=21) versus topical cyclosporine 1% alone (Group 2, n=23). Subjects were randomly divided. In Group 1 subjects were treated with MP 4/day for one week, then 3/day for one week, then 2/day for one week plus CsA 2/day for three months. In Group 2 subjects were treated with CsA 2/day for three months. All patients were advised to continue using artificial tears two-hourly as they were prior to the study. The results found the following at one, two and three months. Greater improvements in Schirmer’s testing and corneal staining (using NEI 1995 report grids) were found in Group 1 at month one, but both groups achieved the same scores at three months. Tear break-up time (TBUT) and conjunctival staining showed improvements at all the time points for both groups. The time from initiation of treatment to symptom relief was shorter in Group 1, 50% of Group 1 patients achieved symptom relief within five weeks, whereas only 10% of Group 2 subjects achieved symptom relief within five weeks (P<0.001). Both groups showed a reduction in tear-film IL-6 and IL-8 at three months compared to baseline. Few side-effects were reported; burning and stinging being the main problems. The authors conclude that intensive treatment with methylprednisolone results in faster symptom relief. The study could have been improved if there was a treatment arm including topical corticosteroids used more widely such as predforte or dexamethsone plus CsA. Six month results would have been useful to assess longer term treatment effect.

Reference

Efficacy of combined 0.05% cyclosporine and 1% methylprednisolone treatment in chronic dry eye.
Byun Y-J, Sim T, Kwon S M, et al.
CORNEA
2012;31(5):509-13.
Efficacy of combined 0.05% cyclosporine and 1% methylprednisolone treatment in chronic dry eye.
Byun Y-J, Sim T, Kwon S M, et al.
CORNEA
2012;31(5):509-13.

Cornea

Thermocautery for inferior conjunctivochalasis
Reviewed by: Sharmina Khan
Aug/Sep 2012 (Vol 19 No 2)
 

This is a novel treatment for symptomatic inferior conjunctivochalasis, which is faster than excision and suturing the conjunctiva. Only those patients who were positive on the ligation test in outpatients then went on to have thermocautery. The ligation test consisted of a 6/0 silk to ligate the redundant conjunctiva followed by esthesiometer testing an hour later to check for recovery in conjunctival and corneal sensitivity and asked if their symptoms had improved. If they answered yes, they went on to have thermocautery. At the slit-lamp the redundant conjunctiva was ablated 3-4mm inferior to the limbus using OPTEMP variable low temperature cauteriser. Patients were followed up for 469.5 +/- 234.6 days and there were no recurrences. Complications included conjunctival hyperaemia, redness, haemorrhage, chemosis, localised cicatrisation with adherence to sclera. This could potentially result in restriction in eye movements if cauterisation was excessive. The authors conclude that the ligation test is necessary to select those who would symptomatically improve and advocate this as an outpatient procedure. In less stoic patients in the UK compared to Japan better control would be achieved in the operating theatre.

Reference

Thermocautery for inferior conjunctivochalasis.
Nakasato S, Uemoto R, Mizuki N.
CORNEA
2012;31(5):514-9.
Thermocautery for inferior conjunctivochalasis.
Nakasato S, Uemoto R, Mizuki N.
CORNEA
2012;31(5):514-9.

Experimental Eye Research

Polymorphisms in repair genes in AMD
Reviewed by: Graham Wallace
Aug/Sep 2012 (Vol 19 No 2)
 

Recent years have shown a strong genetic basis for age-related macular degeneration (AMD). Genes involved in the complement pathway (CFH, BF C2 and C3), on chromosome 10q26 (ARMS / HTRA1) have been linked to oxidative stress and immune reactions that may contribute to AMD. Two new genes 9-oxoguanine (hOGG1) and mutY homolog (MUTYH) encode glycosylases which are involved in DNA repair following oxidative damage. In this study the genotype and allelic frequency of hOGG1 977C and MUTYH 972C single nucleotide polymorphisms were analysed in 269 patients with AMD (100 dry) and 105 healthy controls. The results show an association between hOGG1 977C/G genotype and the G allele with AMD, in particular with the dry form. There was no significant association with MUTYH 972C and disease. The pathogenesis of AMD includes lifestyle factors including smoking which would increases oxidative stress in all tissues. In addition, high metabolic activity in the retina can lead to oxidative changes in molecules like doxohexanoic acid, fragments of which can generate an immune response. Therefore, polymorphisms in genes encoding proteins involved in DNA repair are intriguing. In particular, the association with the dry form of AMD, which is the most common, suggests a role in the initiation of the condition.

Reference

Association between polymorphisms of the DNA base excision repair genes MUTYH and hOGG1 and age-related macular degeneration. 
Synowiec E, Blasiak J, Zaras M, et al.
EXPERIMENTAL EYE RESEARCH
2012;98(1):58-66.
Association between polymorphisms of the DNA base excision repair genes MUTYH and hOGG1 and age-related macular degeneration. 
Synowiec E, Blasiak J, Zaras M, et al.
EXPERIMENTAL EYE RESEARCH
2012;98(1):58-66.

Eye

Agreement between optometrists and ophthalmologists in glaucoma management
Reviewed by: John Brookes
Aug/Sep 2012 (Vol 19 No 2)
 

Over recent years, there has been a steadily increasing number of patients attending hospital glaucoma services. This has increased the burden of such services, due to a combination of demographic changes, National Institute for Clinical Excellence (NICE) guidelines and following a National Patient Safety Agency alert of 2009, which identified patients who had lost vision from lack of appropriate follow-up in glaucoma clinics. Optometrists have become increasingly involved in the co-management of ‘stable’ glaucoma patients and numerous studies have been published to determine the agreement of optometrists and ophthalmologists in the management of these patients. The authors of this study compared the decisions of four diploma-trained optometrists with two consultant glaucoma specialists, of 23-35 patients. The study was divided into two parts; firstly, agreement of glaucoma clinical management decisions, and secondly, the ability of the optometrist to correctly identify glaucomatous and co-existing pathology, requiring a more specialist opinion and / or intervention. Agreement was reasonably good, showing agreement in 68.5%, 64.5%, 84.5% and 96.5%, for visual field assessment, optic disc interpretation, intraocular pressure measurement and medical management, respectively. There was 72% agreement for other management decisions (timing of follow-up, referral to a consultant and discharge). The disagreements between optometrists and ophthalmologists tended to occur because the optometrists were more cautious. The authors state that their study was limited by the small number of patients and the fact that there will always be differences of opinion, despite appropriate qualifications and experience. However, they suggest that optometrists are capable of making assessments of glaucoma patients and making appropriate management decisions and they strongly support an increasing role for them in an over-burdened service to expand and meet demands created by existing and future glaucoma

Reference

Agreement between specially trained and accredited optometrists and glaucoma specialist consultant ophthalmologists in their management of glaucoma patients.
Marks JR, Harding AK, Harper RA, et al.
EYE
2012; 26(6):853-61.
Agreement between specially trained and accredited optometrists and glaucoma specialist consultant ophthalmologists in their management of glaucoma patients.
Marks JR, Harding AK, Harper RA, et al.
EYE
2012; 26(6):853-61.

Eye

The Cataract National Dataset – audit of 55,567 operations
Reviewed by: John Brookes
Aug/Sep 2012 (Vol 19 No 2)
 

The visual acuity of eyes having had cataract surgery is widely used as an outcome measure, despite its known limitations. The ease and universality of its measurement means this will continue for the foreseeable future. This large scale audit reports on the risk factors for visual acuity improvement and harm following cataract surgery. Data was collected electronically from 12 NHS trusts, involving 406 surgeons, amounting to 55,567 operations. Analyses were performed to identify risk factor indicators for, 1) achieving a visual acuity of 6/12 or better, 2) change in pre- to postoperative visual acuity and 3) visual acuity loss. Postoperative visual acuity outcome was known in 73.3% of patients. Overall, 91% of patients achieved a visual acuity of 6/12 or better and the average improvement in visual acuity was 4.0 LogMAR lines. 1.24% of patients experienced loss of vision, defined as a doubling, or worse, of the visual angle. The adverse preoperative risk factor indicators were older age, any ocular co-morbidity, short axial length, age-related macular degeneration, diabetic retinopathy, amblyopia, corneal pathology, previous vitrectomy and posterior capsule rupture (PCR). PCR was found to be the only modifiable adverse risk indicator, with an odds ratio of visual loss of 5.74. The authors state that the magnitude of the impact of PCR is such a strong indicator of visual acuity loss it underlines the relevance and importance of PCR as an accepted benchmark of surgical quality. They also point out, however, that the measurement of monocular visual acuity has significant limitations and does not fully reflect the overall visual experience of the person who has undergone surgery. Therefore, patient reported outcome measures in future will be needed to address postoperative outcomes more fully.

Reference

The Cataract National Dataset electronic multicentre audit of 55 567 operations: risk indicators for monocular visual acuity outcomes.
Sparrow JM, Taylor H, Qureshi K, et al.
EYE
2012;26(6):821-6.
The Cataract National Dataset electronic multicentre audit of 55 567 operations: risk indicators for monocular visual acuity outcomes.
Sparrow JM, Taylor H, Qureshi K, et al.
EYE
2012;26(6):821-6.

Journal of Pediatric Ophthalmology and Strabismus

Consequences of drug exposure in utero
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The authors describe a cohort of 25 children, following exposure to opiates and benzo-diazepines in utero, including changes in visual acuity and nystagmus among 13 children who were observed for six months or longer. Twenty-four children were exposed to opiates (22 to methadone, six to heroin, one to diamorphine and one to dihydrocodeine) and one to diazepam alone. Thirteen were exposed to opiates plus diazepam. Forty percent were referred because of concerns regarding visual development, 32% because of suspected strabismus and 20% with nystagmus. All children had horizontal nystagmus. Eight children adopted an abnormal head posture to dampen nystagmus. Thirty-six had delayed visual maturation, 64% had strabismus and 32% had a history of developmental delay. Forty-eight percent had signs of drug withdrawal after birth. The results demonstrate that nystagmus does not resolve but may improve in some children. Nystagmus and reduced visual acuity is most likely the result of insult to the central nervous system rather than the eyes.

Reference

Nystagmus and reduced visual acuity secondary to drug exposure in utero: long term follow-up.
Gupta M, O’Mulvihill A, Lascaratos G, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):58-63.
Nystagmus and reduced visual acuity secondary to drug exposure in utero: long term follow-up.
Gupta M, O’Mulvihill A, Lascaratos G, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):58-63.

Journal of Pediatric Ophthalmology and Strabismus

Inferior oblique surgery
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The authors evaluated the incidence, behaviour and functional impact of postoperative inferior oblique underaction following unilateral inferior oblique myectomy or recession in 79 patients. Incidence for inferior oblique underaction postoperatively was 35%. There was no predilection for recession or myectomy. Six percent had symptomatic diplopia postoperatively but only 4% had inferior oblique underaction which was successfully corrected with a second procedure.

Reference

Understanding inferior oblique muscle following myectomy or recession for unilateral inferior oblique overaction.
Bhatta S, Auger G, Ung T, Burke J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):43-8.
Understanding inferior oblique muscle following myectomy or recession for unilateral inferior oblique overaction.
Bhatta S, Auger G, Ung T, Burke J.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):43-8.

Journal of Pediatric Ophthalmology and Strabismus

IPD under GA in IDEX
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The aim of this study was to evaluate whether changes in the anatomic interpupillary distance (IPD) following general anaesthesia (GA) were correlated with the preoperative angle of deviation in 40 children with IDEX and, if correlated, to determine whether the relationship could predict surgical outcomes. A photograph of IPD was taken preoperatively and during GA. All patients demonstrated increased IPD following GA. Positive linear correlation was found between the preoperative angle of deviation and changes in IPD. Patients who fell outside the 80% confidence intervals for expected values were more likely to have poor surgical outcomes. Changes in eye position following GA were similar for exotropic patients and ortho patients.

Reference

Changes in the interpupillary distance following general anaesthesia in children with intermittent exotropia: a predictor of surgical outcomes.
Bae HW, Chung SA, Yoon JS, Lee JB.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):49-53.
Changes in the interpupillary distance following general anaesthesia in children with intermittent exotropia: a predictor of surgical outcomes.
Bae HW, Chung SA, Yoon JS, Lee JB.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):49-53.

Journal of Pediatric Ophthalmology and Strabismus

Lens disorders
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The authors report lenticular problems in children from Northern India. One thousand and forty-seven children were registered in a lens clinic over a two-year period. 65.7% were male and the mean age of presentation was 6.35 years ±4.13. Developmental cataract was the most common cause (45.6%) inclusive of congenital cases. Post-traumatic cataract was the second largest group (29.7%). Other groups included cataract with retinal detachment, PHPV, subluxed lens, micro / spherophakia, secondary to uveitis, intraocular lens complications, cataract with coloboma and visual axis opacification.

Reference

Lenticular abnormalities in children.
Khokhar S, Agarwal T, Kumar G, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):32-7.
Lenticular abnormalities in children.
Khokhar S, Agarwal T, Kumar G, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):32-7.

Journal of Pediatric Ophthalmology and Strabismus

Visual field indicators for craniopharyngioma
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The study investigated whether the preoperative visual field is related to presenting symptoms and whether it can be used as a prognostic factor of postoperative visual outcome and recurrence in children with craniopharyngioma. Thirty-two children were reviewed, of which 27 had visual field data. Thirteen (48%) presented with systematic symptoms and 14 (52%) with ocular symptoms. Systematic symptoms included headache, nausea, vomiting, polyuria, polydipsia and growth retardation. Ocular symptoms included visual disturbance, diplopia, strabismus, constricted field and orbital pain. Fifty-six percent had visual acuity <20/40 in both eyes and 48% had normal visual fields. All underwent gross total removal of the tumour. Patients with normal field at presentation were more likely to preserve better visual acuity and normal fields postoperatively. There was no significant difference in tumour size for those with and without field loss. An association was found between field loss at presentation and a higher recurrence rate. The authors recommend meticulous control of tumour during surgery in cases with preoperative field loss and circumspect follow-up for recurrence. Preoperative field loss was also associated with polyuria and polydipsia.

Reference

Initial visual field as a predictor of recurrence and postoperative visual outcome in children with craniopharyngioma.
Lee MJ, Hwang J-M.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):38-42.
Initial visual field as a predictor of recurrence and postoperative visual outcome in children with craniopharyngioma.
Lee MJ, Hwang J-M.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):38-42.

Ophthalmic Research

How can we better detect early glaucoma?
Reviewed by: Uwe Pleyer
Aug/Sep 2012 (Vol 19 No 2)
 

Discrimination of early primary open-angle glaucoma from normal subjects is often difficult. Most types of glaucoma, i.e. primary open-angle glaucoma and low-tension glaucoma, do not demonstrate any apparent anatomic landmark and often present normal tonometric values. In addition, long-term fluctuation in visual field testing and the nonlinear character of progression in anatomic structures, e.g. excavation in optic nerve head make discrimination difficult. Therefore, Robert et al. investigated the ocular pulse amplitude (OPA) as a physiological parameter. Background: the ocular pulse amplitude originates from the heartbeat and travels as a pressure wave along the arterial branches to the ciliary arteries and the choroid. When it enters the eye, the wave demonstrates a purely arterial behaviour. It reaches the sclera / cornea, the aqueous humour and chamber angle, and subsequently the aqueous humour outflow through the trabeculum where it attenuates the pulse wave. Consequently, OPA measurements may be able to detect differences in trabecular outflow characteristics between normal and glaucomatous eyes. The authors hypothesised that OPA is characteristic for the IOP assuming that with the systemic arterial blood pressure the ratio of ocular and arterial pulsation amplitudes is larger in glaucoma patients. This hypothesis was tested in a pilot study based on measurements and calculations in 10 healthy subjects and 11 glaucoma patients. Using a Bi-ocular DCT-OPA assessment synchronised with arterial pulsations the investigators were able to determine blood pressure for each corresponding IOP value every 0.01s for 12 s. Based on these measurements the authors conclude that the ratio of OPA and blood pressure variances is a strong glaucoma diagnostic indicator. Therefore, further investigations are promising for early diagnostic purposes.

Reference

Discrimination of healthy and glaucomatous eyes based on the ocular pulse amplitude: a diagnostic case-control study. 
Robert YC, Wild A, Kessels AG, et al.
OPHTHALMIC RESEARCH
2012;48(1):1-5.
Discrimination of healthy and glaucomatous eyes based on the ocular pulse amplitude: a diagnostic case-control study. 
Robert YC, Wild A, Kessels AG, et al.
OPHTHALMIC RESEARCH
2012;48(1):1-5.

Strabismus

Astigmatic effect on binocularity
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The aim of this study was to evaluate how unilateral uncorrected astigmatic refractive error influences fixation disparity and consequently binocular vision function. Twenty healthy subjects were assessed. Two different amounts of astigmatic blur were used in two different axes to further investigate whether the effect was axis-dependent and / or amplified with higher astigmatic errors. The results indicate that monocular astigmatic blur had no significant effect on fixation disparity. The authors conclude that in general it is likely that monocular astigmatic blur in the amounts of -0.75 and -1.25 are sufficiently small to fall within the range of compensation and that spherical equivalent contact lenses are a viable option for low amounts of astigmatic error without causing any effect on binocular alignment and binocular function.

Reference

The influence of unilateral uncorrected astigmatism on binocular vision and fixation disparity.
Nilsson A, Nilsson M, Stevenson SB, Brautaset RL.
STRABISMUS
2011;19(4):138-41.
The influence of unilateral uncorrected astigmatism on binocular vision and fixation disparity.
Nilsson A, Nilsson M, Stevenson SB, Brautaset RL.
STRABISMUS
2011;19(4):138-41.

Strabismus

EOM changes in enophthalmos
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The authors report a case with delayed onset of diplopia on eccentric gaze following craniotomy for clipping of a basilar artery aneurysm. Diplopia occurred on lateral gaze and upgaze. The operation resulted in enophthalmos from surgical enlargement of the orbit with displacement of the globe posteriorly and resultant shortening of the rectus muscles.

Reference

Extraocular muscle dynamics in diplopia from enophthalmos.
Yoon MK, Economides JR, Horton JC.
STRABISMUS
2011;19(4):142-6.
Extraocular muscle dynamics in diplopia from enophthalmos.
Yoon MK, Economides JR, Horton JC.
STRABISMUS
2011;19(4):142-6.

Strabismus

Prevalence of Iranian amblyopia and strabismus
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The authors report the prevalence of amblyopia and strabismus among school children in Mashhad (second most populated city in Iran). This study was part of a large cross-section eye study. Exactly 2150 students were assessed: 44% female and a mean age of 13 years. Prevalence of amblyopia was 1.9% for girls and 1.7% for boys. Anisometropic amblyopia was the most common type. Prevalence of strabismus was 3.1% for girls and 2% for boys. Strabismus was more common with hypermetropia than myopia and reduced with age, particularly if exotropic. Exotropia was the most common type.

Reference

Amblyopia and strabismus in Iranian school children, Mashhad.
Faghihi M, Ostadimoghaddam H, Yekta AA.
STRABISMUS
2011;19(4):147-52.
Amblyopia and strabismus in Iranian school children, Mashhad.
Faghihi M, Ostadimoghaddam H, Yekta AA.
STRABISMUS
2011;19(4):147-52.

Strabismus

Treatment of residual convergence excess esotropia
Reviewed by: Fiona Rowe
Aug/Sep 2012 (Vol 19 No 2)
 

The aim of the study was to review cases of residual or recurrent convergence excess esotropia in whom bilateral medial rectus posterior fixation sutures with and without central tenotomy were performed as a secondary procedure. Of 11 patients, nine showed immediate improvement in binocular vision and did not require bifocals. Two patients showed smaller angles of deviation and better control without bifocals but their stereopsis was not improved.

Reference

Surgery for residual convergence excess esotropia.
Patel HI, Dawson E, Lee J.
STRABISMUS
2011;19(4):153-6.
Surgery for residual convergence excess esotropia.
Patel HI, Dawson E, Lee J.
STRABISMUS
2011;19(4):153-6.

British Journal of Ophthalmology

A hybrid form of retinopathy of prematurity
Reviewed by: Jonathan Chan
Jun/Jul 2012 (Vol 19 No 1)
 

This is a retrospective case study between January 2006 and June 2010. The authors review the retinal drawings and Retcam images for a hybrid form of retinopathy of prematurity (ROP), which demonstrates both ridge tissue (simulating staged ROP) and flat neovascularisation (simulating aggressive posterior retinopathy of prematurity) (APROP) in the same eye. During the study period there were 138 eyes of 73 infants presented with APROP and 28 (20.29%) of the 138 eyes had hybrid characteristics (i.e. simultaneous presence of flat neovascular syncytium and ridge in the same eye). The mean birth weight and gestational age were 1380.5±308.29g and 29.61±1.94 weeks, respectively. All infants received ventilation and supplemental oxygen (median 15 (range 1-44) days). Three patterns were identified: 1. Ridge at the junction of vascular and avascular retina (14 (50%)eyes); 2. Ridge in the vascularised posterior retina (10 (35.71%)eyes); 3. Ill-defined ridge close to the optic disc, with mat-like fibrous proliferation into the vitreous (four (14.29%) eyes). All infants underwent laser photocoagulation with a diode laser delivered through the indirect ophthalmoscopic system. The mean postconceptional age at laser treatment was 35.27±2.45 (range 31.5-30.5) weeks. The mean number of spots per eye for primary treatment was 1963.75±520.77 (range 1118-3295). Four (16.66%) of the 24 eyes had an unfavourable outcome after laser (stage 4a in two eyes, stage 4b in one eye and cataract in one eye). Both eyes of an infant with pattern 3 disease progressed to stage 4a. The authors commented that the limitation of this study is the non-availability of fluorescein angiogram which could have demonstrated the changes of atypical neovascularisation of the underlying retina.  The presence of plus disease should serve as a guide to treatment in these hybrid form of eyes with ROP.

Reference

A hybrid form of retinopathy of prematurity.
Sanghi G, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(4):519-22.

British Journal of Ophthalmology

Effect of pupil size on uncorrected visual acuity in astigmatic eyes
Reviewed by: Jonathan Chan
Jun/Jul 2012 (Vol 19 No 1)
 

This is a prospective study of 20 eyes of 20 healthy volunteers between the age of 22 and 37 years old, with no previous history of ophthalmic disease or refractive errors. The aim of the paper is to determine the effects of the pupil size on uncorrected visual acuity (UCVA) in astigmatic eyes. The manifest refraction (spherical equivalent) was -1.69±2.20 dioptres (D) (range -6.25 to 0.75D). The manifest refractive cylinder was -0.11±0.25D (range -0.75 to 0.00D). Corneal and ocular higher order aberrations (HOAs) determined using Hartmann-Shack aberrometry were 0.06±0.02µ and 0.10±0.02µ for a 4mm pupil, respectively. Cycloplegic refraction was performed by auto-refraction and undertaken at least 30 minutes after the third administration of Cyclopentolate hydrochloride and only if the pupillary light reflex was absent. After fully correcting the cycloplegic refraction, with-the-rule (WTR) axis 90° against-the-rule (ATR) axis 0° astigmatic of one, two and three dioptres in each eye was produced. They assessed UCVA using artificial pupils (1-5mm) in these eyes. In eyes with a WTR astigmatism of one dioptre, multiple comparisons demonstrated a significant difference between measurements made for a 2mm pupil and for a 5mm pupil, for a 3mm pupil and a 5mm pupil, and for a 4mm pupil and 5mm pupil, but no significant differences between those made for 1mm pupil and a 5mm pupil. In eyes with WTR astigmatism of two dioptres, multiple comparisons demonstrate a significant difference between measurements made for a 1mm pupil and a 5mm pupil, for a 2mm pupil and a 5mm pupil, and for a 3mm pupil and a 5mm pupil, but no significant differences between those made for a 4mm pupil and a 5mm pupil. In eyes with WTR astigmatism of three dioptres, multiple comparisons demonstrated significant difference between measurements made for a 1mm pupil and a 5mm pupil, and for a 2mm pupil and a 5mm pupil, but no significant differences between those made for a 3mm pupil and a 5mm pupil or a 4mm pupil and a 5mm pupil. Similar results were obtained in eyes with ATR astigmatism. It was revealed from the study that UCVA was better in eyes with smaller pupil sizes in almost all cases in which both WTR and ATR astigmatism was present, eyes with larger pupil sizes tended to have a lower UCVA. It indicates that pupil size plays an essential role in a visual performance in astigmatic eyes as well as in non-astigmatic eyes. It was suggested that in eyes with larger pupils, it will be unnecessary to correct the pre-existing astigmatism in order to acquire excellent visual outcomes. It was found UCVA is highest for 2mm pupils in eyes with WTR and ATR astigmatism of one dioptres, where as UCVA is highest for 1mm pupils in eyes with WTR and ATR astigmatism of two and three dioptres.
The authors suggested a further study with greater numbers of subjects is required to confirm this pilot study.

Reference

Effect of pupil size on uncorrected visual acuity in astigmatic eyes.
Kamiya K, Kobashi H, Shimizu K, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(2):267-70.

British Journal of Ophthalmology

Intra-arterial chemotherapy for retinoblastoma
Reviewed by: Jonathan Chan
Jun/Jul 2012 (Vol 19 No 1)
 

This is a retrospective study of 76 eyes of 67 patients with retinoblastoma with sub-retinal and / or vitreous seeding treated by intra-arterial chemotherapy, between May 2006 and August 2010. There were 20 enucleations, eight of which were in eyes with only vitreous seeding, five were in eyes with only sub-retinal seeding, and seven were in eyes with both vitreous and sub-retinal seeding. The medium follow-up for surviving eyes was 2.04 years. Among treatment-naïve eyes, the ocular salvage was 83% for eyes with sub-retinal seeding only, 64% for eyes with vitreous seeding only and 80% for eyes with both. Among eyes that received previous treatment, the two year probability of ocular salvage was 50% for eyes with sub-retinal seeding only, 76% for eyes with only vitreous seeding and 54% for eyes with both. Two patients developed metastatic retinoblastoma and were in remission. Thirty-three (43.4%) eyes received only one drug, 33 (43.4%) received two drugs and 10 (13.2%) received three drugs during the treatment. The median time for retention of the eye was 8.7 months (0.9-30.8). The authors concluded that the treatment appears to be more effective in eyes that failed to respond to previous systemic chemotherapy and have only vitreous seeding.

Reference

Intra-arterial chemotherapy for retinoblastoma in eyes with vitreous and/or subretinal seeding: 2-year results.
Abramson DH, Marr BP, Dunkel IJ, Brodie S.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(4):499-502.

British Journal of Ophthalmology

Keratoconjunctivitis sicca and Sjogren’s syndrome
Reviewed by: Jonathan Chan
Jun/Jul 2012 (Volume 19 No 1)
 

This is a retrospective study of a review of medical records of patients diagnosed with Sjogren’s syndrome (SS); a total of 121 patients from Korea. Patients were divided into two groups, a mild keratoconjunctivitis sicca (KCS) group (Mi-KCS) of 65 patients and a moderate to severe group (MS-KCS) group of 56 patients. They were then sub-divided into two sub-groups based on the clinical severity of the KCS and the presence of associated rheumatic disease (primary SS vs. secondary SS). They analysed the blood results of anti-Ro / anti-La antibodies, rheumatoid factor and tear interleukin (IL)-17 levels and Shirmers test results between each group. It was found that the number of the patients with anti-La / SSB autoantibody was significantly higher in the MS-KCS group than in the Mi-KCS group for both total SS and primary SS. Serum concentration of rheumatoid factor (RF) was higher in the secondary SS than in primary SS regardless of the clinical severity of KCS. Mean tear IL-17 concentration in the MS-KCS group was significantly higher than in the Mi-KCS group in both total SS and PSS patients. Anti-Ro / SSA positivity were similar in the Mi-KCS and MS-KCS group for both total SS and primary SS. RF positivities showed no relationship with clinical severity. This study confirmed that serum anti-La / SSB antibodies is likely to be intricately involved in the clinical severity of the KCS in patients with SS. The concentrations of anti-Ro / SSA anti-IL-17 were found to be related to the clinical severity of KCS in SS.

Reference

Prognostic factors for clinical severity of keratoconjunctivitis sicca in patients with Sjogren’s syndrome.
Chung JK, Kim MK, Wee WR.
BRITISH JOURNAL OF OPHTHALMOLOGY
2012;96(2):240-5.

Clinical and Experimental Ophthalmology

ROP in extremely premature infants
Reviewed by: Kwesi Amissah-Arthur
Jun/Jul 2012 (Vol 19 No 1)
 

The survival rates of extremely premature infants have improved dramatically over the last two decades due to progressive improvement in neonatal practice. However, with this improvement in survival of extremely premature infants (gestational age of less than 28 weeks) comes a higher risk of retinopathy of prematurity (ROP). This retrospective study by Gunn et al. looked at 554 infants admitted between 23 and 25.6 weeks gestational age (GA) from a single tertiary neonatal intensive care unit over an 18-year period. Screening examinations were performed on all infants with GA <32 weeks or birth weight <1500g, and continued biweekly or weekly if significant ROP was detected. Initial examinations were performed on infants at approximately 32 weeks post-menstrual age. A single paediatric ophthalmologist performed all the ROP screening. The criteria used for staging of disease were according to the International Classification of ROP. The 18-year study was divided into three six-year periods for comparison: period one (1992-1997), period two (1998-2003) and period three (2004-2009). Infants were compared based on their week of gestational age and by the study period in which they were born. Birth weights were analysed using one-way analysis of variance (ANOVA) with Bonferroni correction. Data were compared with contingency tables and the use of Fisher’s exact test. Risks for development of ROP were modelled with univariate and multivariate logistic regression analyses. Three hundred and seventy-three (67.3%) infants survived until ROP screening, and 351 (63.4%) survived until discharge. There were 185 males and 188 females in the 373 screened infants. ROP was found in 83.2% (154/185) of males and 79.8% (150/188) of females. Mean birth weight was significantly lower in infants with any ROP (725.1g) and ROP of at least stage three (720.8g) compared with infants without ROP (806.5g) (P<0.0001). Twenty-three week GA infants had more severe ROP (28.6%) than 24 weeks (18.3%) and 25 weeks GA (11.9%). Of the 373 infants examined, 128 eyes from 66 individuals (17.6%) subsequently required laser diode treatment, while 2.1% of individuals (8/373) displayed Rush disease, later designated as aggressive posterior ROP. Regression analysis found that birth weight and gender were both insignificant predictors of development of severe ROP (P=0.90 and P=0.45), with gestational age being a significant predictor of severe ROP (P=0.014). This paper should be read with the understanding that the data is over a prolonged period of time, and that there have been some changes in the management of ROP, especially following the early treatment of ROP study. However, as one individual exclusively screened all infants in this retrospective study, the confounding factor of multiple examiners and screeners is avoided. The authors point out in their conclusion that there now exists a developing population of surviving infants with extremely low birth weight who are at high risk for the development of ROP with the potential consequence of lifelong poor vision, this is certainly information that all ophthalmologists should be aware of.

Reference

Incidence of retinopathy of prematurity in extremely premature infants over an 18-year period.
Gunn DJ, Cartwright DW, Gole GA.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2011;40(1):93–9.

Clinical and Experimental Opthalmology

Prevalence of trachoma in a single community
Reviewed by: Kwesi Amissah-Arthur
Jun/Jul 2012 (Vol 19 No 1)
 

Australia is the only developed country in the world where blinding trachoma still occurs. Trachoma was eradicated in the non-indigenous Australian population in the 1930s, however, this is not the case in aboriginal communities. This study by Taylor et al. compares two cross-sectional studies in children aged 5 to 13 years living in a remote aboriginal community in the Katherine region of the Northern territory. The two cross-sectional studies were performed in the same community 32 years apart, they occurred in 1975 and 2007. The cross-sectional study that took place in 1975 was part of a total population survey of the general health of the people living in the community. A complete ophthalmic examination was performed and a photograph of the everted upper eyelid was taken using 35mm kodachrome film. In 2007, a further population based study was conducted in the same community. During this study, digital photographs were taken of the left eyelid of each person using a Nikon D40 camera and an 85mm lens. A fine grading scale previously reported by the same group was used to measure the presence and severity of trachomatous inflammation follicular (TF), trachomatous inflammation intense (TI) and trachomatous scarring (TS). All images were graded twice, with the grader masked to the clinical details and to previous grading. Where there was a disagreement a third grading was sought. The primary outcome measure was the age-specific prevalence and severity of trachoma, which was compared at the two time points. There were 82 images from 1975 and 92 from 2007. The overall prevalence of active trachoma (trachomatous inflammation follicular and / or trachomatous inflammation intense) was 59% in 1975 and was significantly lower in 2007 at 23% (P<0.001). The overall severity grades of active trachoma had also decreased significantly for each sign from 1975 to 2007 (all P values from the rank-sum test were less than 0.001). The interaction between age and study year was not found to be significant (P=0.86). However, in 2007, there were still some children with severe active trachoma and severe scarring still occurred. National efforts to eliminate trachoma must be guided by good epidemiologic data. This study shows that the rate of trachomatous scarring has been reduced substantially over the last 32 years. However, active trachoma (TF) still exceeds the threshold prevalence of less than 5% that has been set by the World Health Organisation (WHO) for blinding trachoma to be no longer a public health problem. The authors of this paper acknowledge that a limitation of the study was the inability to mask the photographs from 1975 which were 35mm slides, from the digital images collected in 2007. They end by stating that the metaphorical glass still has water in it and that one could argue about whether it is half full or half empty. As summarised by the editorial in the journal, this work by Taylor et al. can be used to estimate the likelihood of trachoma elimination and aid in planning and policy, as there are two data points available. However, more work needs to be done to effect policy change such that the glass is filled and the health disparity index that still exists between indigenous and non-indigenous Australians in relation to trachoma is closed

Reference

Prevalence of trachoma in a single community, 1975-2007.
Taylor HR, English DR, Field BA, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2012;40(2):121-6.

Cornea

Descemet’s membrane endothelial transfer
Reviewed by: Sharmina Khan
Jun/Jul 2012(Vol 19 No 1)
 

This an interesting case of Descemet’s membrane endothelial keratoplasty (DMEK) that went wrong but host endothelial cells nevertheless still repopulated. An 80-year-old woman with Fuchs’ endothelial dystrophy in a pseudophakic eye underwent a DMEK procedure under local anaesthesia. A few hours after surgery the donor tissue reformed into a scroll and was free-floating in the anterior chamber (AC) except for host touch in the periphery at 12 o’clock. The patient did not want to be taken back to theatre. Month by month the corneal oedema resolved and at six months the cornea was completely clear with normal pachymetric readings. Best corrected visual acuity (BCVA) was 20/200 (she also had macular degeneration) not improving with pinhole. The position of the Descemet’s roll remained unchanged. By six months the endothelial cell count was 830 cells per square millimetre. The authors postulate that an injection of endothelial cells on Descemet’s membrane as the carrier may prove effective in managing endothelial disorders. However, the downsides are that the VA takes six months to improve compared to one to three months after Descemet's stripping automated endothelial keratoplasty (DSAEK) or DMEK and the endothelial cell count achieved at six months is not as high as a DMEK procedure.

Reference

Descemet’s membrane endothelial transfer: free floating donor descemet implantation as a potential alternative to keratoplasty.
Dirismaer M, Ham L, Dapena I, et al.
CORNEA
2012;31(1):194-7.

Cornea

Intraoperative corneal thickness measurements
Reviewed by: Sharmina Khan
Jun/Jul 2012 (Vol 19 No 1)
 

This study reports the sequential application of iso-osmolar riboflavin followed by hypo-osmolar riboflavin when intraoperative corneal ‘thinning’ (less than 400µm following removal of epithelium according to Hafezi protocol) was noted in order to cause stromal swelling and increase corneal thickness to above 400µm prior to ultraviolet A (UVA) exposure and iso-osmolar riboflavin solution was applied for the 30 minute duration of the UVA exposure. The authors quite rightly conclude that in a ‘thin’ cornea a hypo-osmolar solution should be used throughout the procedure. It is unsurprising that an iso-osmolar solution containing Dextran has a corneal thinning effect (a Dextran solution is used to de-swell donor corneal allograft tissue)

 

Reference

Intra-operative corneal thickness measurements during corneal collagen cross-linking with hypoosmolar riboflavin solution in thin corneas.
Kaya V, Utine CS, Yilmaz OF.
CORNEA
2012;31:486-90.

Cornea

SCIT versus topical treatment VKC
Reviewed by: Sharmina Khan
Jun/Jul 2012 (Vol 19 No 1)
 

This prospective randomised study compared the novel immunotherapy regime subcuataneous allergen-specific immunotherapy (SCIT) versus topical fluoromethalone plus topical sodium cromoglycate. Immunotherapy is a process that gradually desensitises the body to allergens by injecting increasing volumes of the allergen intradermally over many months (in this study over 24 months), resulting in a dampening of acute hypersensitivity reaction. Efficacy was monitored by improvement in symptoms and reduction in total serum IgE. The study reports a significant reduction in symptoms and serum IgE in the SCIT group by 72% versus the FML / sodium cromoglycate group, 59% (p<0.05%). They reported no side-effects in those treated with SCIT. The efficacy of this promising treatment deserves further investigation due to the prevalence of allergic eye disease and the visually devastating consequences of vernal keratoconjunctivitis in particular.

Reference

Subcuataneous allergen-specific immunotherapy (SCIT) versus topical treatment in vernal keratoconjunctivitis (VKC).
Mahdy RAR, Nada WM, Marei AA.
CORNEA
2012;31:525-8.

Current Eye Research

Use of tacrolimus and octreotide in glaucoma filtration surgery
Reviewed by: Badrul Hussain
Jun/Jul 2012 (Vol 19 No 1)
 

In contrast to other types of surgery, successful glaucoma filtration surgery occurs when incomplete healing allows aqueous humour to escape the eye in a controlled fashion. Many modalities have been used to prevent complete wound healing. The use of mitomycin-C (MMC) and 5-fluorouracil (5-FU) are often associated with adverse effects. More selective and less toxic agents are needed to modulate the wound healing process in filtration surgery. This study investigated the effects of topically administered tacrolimus (an immunosuppressive agent) and octreotide (a synthetic octapeptide analogue of somatostatin). A total of 28 New Zealand rabbits were randomly divided into four groups: one control and three experimental groups. Standard filtration procedures were carried out in the right eye of all 28 rabbits. The rabbits in the control group received one drop of saline four times a day (SC group). The rabbits in the three experimental groups were treated with either with 0.4mg/ml MMC during the surgery (MMC group) or with 0.3mg/ml tacrolimus drops four times a day (TT group) or 10µg/ml octreotide drops three times a day (OT group). On day 14 the animals were killed and eyes enucleated for analysis. The SC group’s mean fibroblast, mononuclear cell number, FGF-β, TGF-β immunostaining intensity was higher than all treatment groups. In the OT group, mean fibroblast number was lower than in the MMC group (p<0.05) and the TT group (P<0.05). In the TT group, mean fibroblast number was less the in the MMC group (p<0.05). Mean mononuclear cell number was similar in the treatment groups (p>0.05). Immunostaining intensity of FGF-βand TGF-β was also similar in the treatment groups (P>0.05). Although further studies are needed to determine the exact fibroblast inhibitory mechanisms of tacrolimus and octreotide, as well as the precise human dosage, this study appears to demonstrate that topical administration of these two agents effectively reduced the subconjunctival scarring response two weeks after experimental glaucoma surgery. If this is indeed the case, they may be alternative, if not better, options to the use of MMC.

Reference

Modulation of postoperative scarring with tacrolimus and octreotide in experimental glaucoma filtration surgery.
Arslan S, Aydemir O, Güler M, Dağlı AF.
CURRENT EYE RESEARCH
2012;37(3):228-33.

Experimental Eye Reseach

Neural progenitor cells in PVR
Reviewed by: Graham Wallace
Jun/Jul 2012 (Vol 19 No 1)
 

Neural stem / progenitor cells (NSC) are involved in the development of the human neuroretina that becomes integrated with the central nervous system. In adult humans the retina has limited regenerative potential, however, in other species such as fish and amphibians, NSC are present and can develop new retinal neurons throughout life. Evidence of NSC in the adult human eye has led to investigation in mouse models, but the results suggest a limited potential for these cells, which appear quiescent in the adult. This paper investigated whether NSC are activated in an inflammatory condition proliferative vitreoretinopathy (PVR). Cells bearing markers for NSC were identified in peripheral retina (PR) and ciliary body epithelium (CE) from control human eyes, eyes with confirmed PVR, and a murine model of PVR. Moreover, cells from vitreous obtained during vitrectomy were stained for markers of NSC and cultured. The results showed expression of the markers, nestin, Sox2 and Pax6 in normal human pars plana and PR. In PVR eyes, no positive cells were found in the CE except around pars plana cysts and the ora serrata region. In culture cells developed into spheres expressing glial and NSC markers in 7/10 samples from PVR patients but on 2/15 for normal individuals. The results suggest two potential populations of NSC in the human adult eye, a non-glial population in the pars plana and a population with glial characteristics. Only the latter responded to retinal injury as demonstrated by migration into the vitreous. Understanding how these different cells are controlled would aid our ability to protect / regenerate retinal tissue following damage.

Reference

Activation of neural progenitor cells in human eyes with proliferative vitreoretinoipathy.
Johnsen EO, Frøen RC, Albert R, et al.
EXPERIMENTAL EYE RESEARCH
2012;98(1):28-36.

Experimental Eye Research

Retinoic acid induced conversion of T regulatory cells
Reviewed by: Graham Wallace
Jun/Jul 2012 (Vol 19 No 1)
 

Retinoic acid (RA), a derivative of vitamin A, is present in retinal pigment epithelial cells (RPE) where it helps to maintain the monolayer structure. RA functions through interaction with the retinoic acid receptor (RAR) and the retinoid X receptor (RXR). Previous studies have shown that naive T cells are differentiated into regulatory T cells on incubation with RPE cells through factors including transforming growth factor-β (TGFβ) and thrombospondin-1. Recent reports have demonstrated that RA enhances the induction of T regulatory cells in the presence of TGFβ. This study addressed whether RPE RA could also induce Tregs. Cultured RPE cells constitutively expressed RA-associated molecules and receptors, and RPE from normal but not vitamin A deficient mice contained TGFβ. Tregs induced by RPE from vitamin A deficient mice failed to suppress effector T cell activity. RAR antagonism or siRNA inhibition of RA in RPE cells inhibited Treg induction. Few Tregs were found in the intraocular cells in experimental autoimmune uveitis in vitamin A-deficient mice. This data supports RA production by RPE cells involvement in T regulatory cell development in the presence of TGFβ. This work compliments a recent publication that described RA and TGFβ in aqueous humour converting naive T cells to Tregs, (Zhou, et al. J Immunol 2011;187:4107-70) suggesting this may be a common pathway in ocular tissues.

Reference

Retinoic acid from retinal pigment epithelium induce T regulatory.
Kawazoe Y, Sugita S, Keino H, et al.
EXPERIMENTAL EYE RESEARCH
2012;94(1):32-40.

Eye

Comparison of trabeculectomy and Ex-PRESS shunt
Reviewed by: John Brookes
Jun/Jul 2012 (Vol 19 No 1)
 

Trabeculectomy is the most common incisional procedure for intraocular pressure (IOP) reduction and its success rate and complications are well established. In recent years, there has been a move to introduce other methods of reducing IOP, which may have a lower rate of short-term and long-term complications. This study is a prospective, randomised study, comparing IOP-lowering and complications in trabeculectomy, compared with the Ex-PRESS glaucoma filtration device, in different eyes of the same patient. The latter procedure closely resembles a trabeculectomy but offers the advantage of a stented sub-scleral outflow route. The study reports on 30 eyes of 15 patients, with a mean follow-up of two years. At last follow-up, mean preoperative IOP decreased from 31.1mmHg to 16.2mmHg after trabeculectomy and from 28.1mmHg to 15.7mmHg after the Ex-PRESS implant. The mean number of postoperative glaucoma drops also decreased in both groups, from 3.7 (both groups) to 0.9 after trabeculectomy and 0.3 after Ex-PRESS implantation. Postoperative complications were more frequent after trabeculectomy (33% versus 20%). However, the complication rate from trabeculectomy was significantly greater than reported in other studies, with up to 33% of patients experiencing hypotony. The main limitations of the study are the relatively small sample and lack of masking and the cost of the Ex-PRESS shunt should also not be forgotten, especially in a public health care setting. This study should be commended for its attempt to show alternatives to trabeculectomy surgery but more long-term studies are required before it will ever be considered as an alternative to trabeculectomy.

Reference

Comparison of trabeculectomy and Ex-PRESS implantation in fellow eyes of the same patient: a prospective, randomised study.
Dahan E, Ben Simon GJ, Lafuma A.
EYE
2012;26(5):703-10.

Eye

Endophthalmitis and open globe injuries
Reviewed by: John Brookes
Jun/Jul 2012 (Vol 19 No 1)
 

Endophthalmitis is a potentially devastating complication of open globe injury. There is a tenfold higher incidence of infection when compared with intraocular surgery. Post-traumatic endophthalmitis is typically associated with worse visual acuity outcomes. This is thought to be due to a variety of factors, including more virulent organisms and possible delayed diagnosis and initiation of treatment. This paper looks at the current literature regarding the clinical aspects of traumatic endophthalmitis and looks at strategies to reduce the visual impact of this disease. Studies have shown that post-traumatic endophthalmitis comprises about 25% of all infectious endophthalmitis cases. Prophylactic factors in the setting of trauma include primary wound repair within 24 hours, lack of tissue prolapse into wounds and self-sealing wounds. Some reviews have reported higher incidences of traumatic endophthalmitis associated with non-metallic intraocular foreign body (IOFB). Factors associated with an increased risk of endophthalmitis following penetrating trauma include retained IOFB, delayed wound closure for more than 24 hours, injury in a rural setting and ruptured lens capsule. There is a high incidence of Bacillus species endophthalmitis following open globe injuries, particularly in the setting of IOFB or soil contamination. Infection caused by Bacillus is characterised by a rapid onset of severe pain and inflammation, hypopyon, chemosis and a ring shaped corneal infiltrate and rapid progression to panophthalmitis. Polymicrobial infection is more frequent in endophthalmitis following open globe injuries, the most common being S. epidermidis and Streptococcus species. The literature suggests that the most important prophylactic methods in the prevention of post-traumatic endophthalmitis is primary globe repair within 24 hours and comprehensive prophylactic antiobiotic treatment at the time of injury repair.

Reference

Endophthalmitis following open-globe injuries.
Ahmed Y, Schimel AM, Pathengay A, et al.
EYE
2012;26(2):212-7.

Journal of Pediatric Opthalmology and Strabismus

fMRI changes in strabismus
Reviewed by: Fiona Rowe
Jun/Jul 2012 (Vol 19 No 1)
 

The purpose was to use fMRI to assess changes in cortical activity related to suppression of visual perception from one eye in the setting of strabismus. The authors utilised a simple dichoptic viewing paradigm together with fMRI to investigate whether it was possible to observe changes in cortical activation in primary visual cortex associated with extrafoveal perception suppression in strabismic individuals. Results indicated that cortical activity modulations correlated with modulation of strabismus suppression are detectable in non-amblyopic individuals but not in amblyopic subjects.

Reference

Functional magnetic resonance imaging of binocular interactions in visual cortex in strabismus.
Chen VJ, Tarczy-Hornoch K.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(6):366-74.

Journal of Pediatric Opthalmology and Strabismus

IDEX postop alignment
Reviewed by: Fiona Rowe
Jun/Jul 2012 (Vol 19 No 1)
 

The panel discussed the case management of a four-year-old at a three-day postoperative visit following bilateral lateral rectus recession for an exotropia of 10PD at near and 14PD at distance fixation and with intermittent diplopia. The discussion centred on preoperative discussions required with parents about the possibility of this occurrence to help prevent parental concern postoperatively. The panel discussed the use of Fresnel prisms if the child was very symptomatic with diplopia and the use of the prism adaptation test preoperatively to help detect cases likely to have diplopia postoperatively. Consensus was obtained that follow-up should be at four to six weeks and if still esotropic, to consider reoperation to prevent loss of binocular vision and development of amblyopia.

Reference

Preferred postoperative alignment in divergence excess intermittent exotropia.
Panelists: Olitsky SE, Strominger MB, Weaver DT.
Moderator: Wagner RS.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):5-7.

Journal of Pediatric Opthalmology and Strabismus

RCT of IO myectomy or recession
Reviewed by: Fiona Rowe
Jun/Jul 2012 (Vol 19 No 1)
 

A randomised double masked clinical trial (RCT) was undertaken on 50 patients (82 eyes). The results showed that both inferior oblique (IO) myectomy and inferior oblique recession techniques effectively improve the inferior oblique overaction and both methods are comparable in achieving a satisfactory result. There was no statistically significant difference between the two groups for rate of residual muscle overaction or underaction, changes in horizontal or vertical deviation, V pattern and dissociated vertical deviation (DVD).

Reference

A randomised clinical trial comparing myectomy and recession in the management of inferior oblique muscle overaction.
Rajavi Z, Molazadeh A, Ramezani A, Yaseri M.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(6):375-80.

Journal of Pediatric Opthalmology and Strabismus

VA changes following nystagmus surgery
Reviewed by: Fiona Rowe
Jun/Jul 2012 (Vol 19 No 1)
 

This paper details the authors’ experience with abnormal head posture correcting procedures and reports binocular visual acuity (VA) improvement following surgery. Surgery included Anderson-Kestenbaum procedure or modified Anderson procedure for 28 patients. Improvement in VA was seen regardless of the type of surgical procedure. There was no correlation between the improvement in VA and improvement in head posture

Reference

Improvement in visual acuity following surgery for correction of head posture in infantile nystagmus syndrome.
Kumar A, Shetty S, Vijayalakshmi P, Hertle RW.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(6):341-6.

Journal of Pediatric Opthamology and Strabismus

QoL following congenital cataract
Reviewed by: Fiona Rowe
Jun/Jul 2012 (Vol 19 No 1)
 

The authors used the NEI-VFQ-25 to assess vision-related quality of life for adolescents and young adults who underwent surgery for bilateral or unilateral congenital cataract in the first two years of life. Congenital cataract was removed before 24 months of life in 38 patients (16 unilateral and 22 bilateral). The authors found a high degree of educational attainment with all in or completed main stream school and half at University. Unilateral cataract scored significantly better in activities than bilateral cataract cases who had greater difficulty with vision-specific social functioning and role difficulties plus vision-specific mental health scores. Both groups were comparable in terms of general vision scores

Reference

Vision-related quality of life assessment using the NEI-VFQ-25 in adolescents and young adults with a history of congenital cataract.
Kirwan C, Lanigan B, O’Keefe M.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2012;49(1):26-31.

Opthalmic Genetics

Differentiating Alström from Bardet-Biedl syndrome
Reviewed by: Nana Theodorou
Jun/Jul 2012 (Vol 19 No 1)
 

There is significant clinical variability between Alström and Bardet-Biedl syndrome (BBS). The authors describe that Alström syndrome is characterised by early onset retinopathy, obesity, hearing loss, kidney dysfunction, insulin resistance and occasional dilated cardiomyopathy. BBS comprises of cone-rod or rod-cone degeneration, obesity, polydactyly, renal anomalies, hypogonadism and cognitive impairment. Previous research reports 16 known genes for BBS and one for Alström syndrome. A total of 96 patients with the BBS diagnosis were included. Samples of purified DNA were sequenced for ciliopathy genes. BBS known gene mutations were found in 44 patients. ALMS1 mutations were found in four cases. The rate of ALMS1 mutations among patients suspected of having BBS was 4.2%. The authors propose that ciliopathy genes sequencing is a useful diagnostic tool in suspected BBS cases of retinal dystrophy associated with obesity and developmental delay

Reference

Differentiating Alström from Bardet-Biedl syndrome (BBS) using systematic ciliopathy genes sequencing.
Aliferis K, Hellé S, Gyapay G, et al.
OPHTHALMIC GENETICS
2012;33(1):18-22.

Opthalmic Genetics

Ocular manifestations of Noonan syndrome
Reviewed by: Nana Theodorou
Jun/Jul 2012 (Vol 19 No 1)
 

Noonan syndrome has an estimated incidence ranging from 1:1000 to 1:2500 live births and follows an autosomal dominant inheritance pattern. The authors describe the main characteristics as short stature, congenital heart defects and facial dysmorphism. This article set out to describe the ophthalmological characteristics in a subgroup of patients with Noonan syndrome and proven mutations in the PTPN11 gene. A total of 35 patients were identified with a mean age of 12 years and 11 months. All patients underwent ophthalmological examination to include external inspection, slit-lamp biomicroscopy and dilated fundus check. External ophthalmological features were identified in 97% of patients with the main features being downslanting palperbal features, hypertelorism, ptosis and proptosis. The most prevalent anterior segment findings consisted of prominent corneal nerves in 51%. Less prominent features included strabismus in five patients and fundus changes in three patients. The authors conclude that their findings are in agreement with previous reported studies so that ocular abnormalities are common in Noonan syndrome and that eyelid and external abnormalities are the prevailing features.

Reference

Ocular manifestations of Noonan syndrome.
Da Rocha Pitta Marin L, da Silva F, de Sa L, et al.
OPHTHALMIC GENETICS
2012;33(1):1-5.

Opthalmology

Musculoskeletal disorders in ophthalmologists
Reviewed by: Nathaniel Knox Cartright
Jun/Jul 2012 (Vol 19 No 1)
 

Musculoskeletal injuries are both the most frequently occurring workplace injuries and also the leading cause of unplanned absence from work. Several previous studies have found that ophthalmologists have a higher prevalence of this type of problem than would be expected but failed to include a reference group for comparison. In this study, physicians from the ophthalmology and general practice departments at a two US centres were asked to complete an online survey enquiring about participant demographics, personal health, musculoskeletal symptoms, potentially contributing job factors and occupational psychosocial stress. Demographic factors were similar between the two groups. It was found that ophthalmologists had a higher prevalence of neck pain (46% vs. 21%; p<0.01), hand / wrist pain (17% vs. 7%; p=0.03) and lower back pain (26% vs. 9%; p<0.01). A greater proportion of the ophthalmologists classified their job as being high demand / low control (31% vs. 20%) and a lower proportion classified their job as an being high demand / high control (24% vs. 47%; p=0.01). The requirement to use microscopes in both the clinic and operating theatre accompanied the need to assume repetitively specific postures and hand positions, often twisting and bending while doing so, presumably accounts for the higher prevalence of these problems among ophthalmologists. This highlights the importance of appropriate ergonomics, including basic factors such as availability of correctly sized chairs.

Reference

A survey study of musculoskeletal disorders among eye care physicians compared with family medicine physicians.
Kitzmann AS, Fethke NB, Baratzet KH.
OPHTHALMOLOGY
2012;119(2):213-20.

Orbit

Primary closure versus multi-staged excision for eyelid BCC
Reviewed by: Konal Saha
Jun/Jul 2012
 

The authors present a retrospective, interventional case series of 90 patients with eyelid basal cell carcinoma (BCC). Thirty-nine percent underwent excision with primary closure and the remainder multi-staged excision (MSE) (delayed closure following histological examination of the specimen). Patients listed for MSE had larger lesions and were more likely to involve the medial canthus. There was a striking difference in the rate of histological clearance between the two groups. Thirty-four percent of the primary closure group had incomplete clearance, compared to 5.5% of the MSE group. Regardless of which group the patients fell in to the intention was to excise the lesions with a 3mm margin. The authors do not comment on why there was a difference in the tumour clearance rate between the two groups but do go on to recommend multi-staged excision for eyelid BCC. The high rate of incomplete clearance in the primary closure group could be due to a number of reasons such as minimising the specimen size to below a 3mm margin in order to allow a primary closure without complicated reconstruction and experience of the assessing oculoplastic surgeon in determining the macroscopic tumour margin.

Reference

High rate of incomplete resection after primary excision of eyelid bcc: multi-staged resection rarely needs more than two procedures.
Kadyan A, Edmunds MR, Amissah-Arthur KN, Durrani OM.
ORBIT
2011;30(6):275-9.

Retina

Effect of intavitreal triamcinolone injection during vitrectomy
Reviewed by: Nikolaos D. Georgakarakos 
Jun/Jul 2012 (Vol 19 No 1)
 

he authors aimed to investigate the effect of intravitreal triamcinolone during vitrectomy for idiopathic epiretinal membrane surgery. Patient’s eyes were divided into two groups: 27 eyes in group one that received 4mg triamcinolone at the end of vitrectomy (23 or 25G) and 31 eyes in the control group two that did not receive the injection. Best corrected visual acuity (logMAR), foveal thickness, complications were compared between the two groups at one, two, three, six and twelve months after surgery. During follow-up, neither visual acuity nor foveal thickness had significant difference regarding gauge of vitrectomy, simultaneous phacoemulsification and internal limiting membrane (ILM) peeling. Addition of triamcinolone had no effect on the postoperative functional and anatomical outcomes.

Reference

Effect of intavitreal triamcinolone injection during vitrectomy for idiopathic epiretinal membrane.
Ahn J-H, Park H-J, Lee J-E, Oum B-P.
RETINA
2012;32(5):892-6.

Retina

PPV for repair of primary RRD
Reviewed by: Nikolaos D. Georgakarakos 
Jun/Jul 2012 (Vol 19 No 1)
 

This retrospective interventional case series of consecutive patients (93 eyes) evaluated the anatomical and functional outcomes of 20g or 23g pars plana vitrectomy (PPV) without buckles, 360 laser, heavy liquid for the surgical treatment of primary uncomplicated rhegmatogenous retinal detachment (RRD) of a 10 year period with a mean follow-up of 31 months. Final reattachment was achieved in 95.7% of cases after a single operation. Traumatic retinal detachment (RD), proliferative vitreoretinopaty (PVR) C1 or greater, prior vitreoretinal surgery, endophthalmitis, giant retinal tear, or <six months follow-up were excluded from the study. The mean age was 60+/-12 years and 52.7% were macula off with a 43.0% phakic status at presentation. Four eyes had recurrent detachment (three due to PVR and one due to incomplete break closure) and epiretinal membrane (ERM) was noted postop in 11 eyes. Glaucoma developed in two eyes which had preop ocular hypertension. Cataract was noted postop in the phakic patients in 62.5% of cases (25 of 40 eyes). The macula off RD eyes did not have a statistically significant change in postop visual acuity. Overall, the mean best corrected visual acuity was found to be significantly improved at the six months (logMAR 0.31, Snellen 20/41, p<0.00005) and final (logMAR 0.29, Snellen 20 / 39, p<0.00005) follow-up visits compared to the preoperative visit (logMAR 0.90, Snellen 20/159). The authors’ preference for type of procedure concurs with the prevailing preference for scleral buckles alone in selected cases of RD (young phakic eyes without posterior vitreous detachment (PVD)) and buckles with PPV in cases with PVR. Their data suggest that when the operation of choice for primary RRD repair is a PPV, a minimalistic simple approach without adjuvant procedures can offer high anatomical and functional results which compare well with existing published papers.

Reference

Pars plana vitrectomy without adjuvant procedures for repair of primary rhegmatogenous retinal detachment.
Schneider E, Garets R, Johnson M.
RETINA
2012;32(2):213-9.

Retina

Predictors of tubercular uveitis
Reviewed by: Nikolaos D. Georgakarakos 
Jun/Jul 2012 (Vol 19 No 1)
 

This paper looks into clinical parameters that may help in diagnosing tubercular versus sarcoid uveitis. This retrospective, non-randomised, comparative study was based on 51 patients of Indian origin with a biopsy-proven diagnosis of tuberculosis or sarcoidosis. The patients had minimum one year follow-up and multiple logistic regression analysis was performed. The duration of intraocular inflammation before biopsy was between one and 132 months and the commonest site of biopsy was the transbronchial lymph node. The commonest ocular sign was panuveitis. The multivariate logistic regression analysis shows the likelihood of tubercular uveitis (as opposed to sarcoid) using three variables: Schirmer test >10mm, retinal vasculitis with multiple pigmented chorioretinal atrophy along blood vessels and a positive Mantoux test (76.6%). This study is limited by its retrospective nature and it could be used as a basis for planning future prospective studies.

Reference

Predictors of tubercular uveitis: a comparison between biopsy-proven cases of tubercular and sarciod uveitis.
Babu K, Kini R, Mehta R, et al.
RETINA
2012;32(5):1017-20.

Strabismus

Superior oblique tuck surgery
Reviewed by: Fiona Rowe
Jun/Jul 2012 (Vol 19 No 1)
 

The authors report the results of superior tuck for management of superior oblique palsy over a 17-year period. The aims of this paper were to report the improvement in vertical and cyclo deviation, assessment reoperation rates, report complications, investigate the correlation between tuck size and deviation change, and report differences between the results for congenital and acquired superior oblique palsy. Seventy-five cases were reviewed with a mean age of 46.5 years. Mean follow-up was 8.6 months and 53% were left-sided. Seventy-one percent showed resolution of diplopia. Twenty-eight percent required one further surgical procedure and one patient had two further procedures. There were no intraoperative complications. Asymptomatic Brown’s syndrome was noted in ten cases but there was no correlation between tuck size and change in deviation. Results for acquired palsy were not significantly different to congenital palsy. The authors conclude that superior oblique tuck is a safe and effective procedure.

Reference

Superior oblique tuck: its success as a single muscle treatment for selected cases of superior oblique palsy.
Durnian JM, Marsh IB.
STRABISMUS
2011;19(4):133-7.

American Journal of Ophthalmology

Predictors of visual outcome in epiretinal membrane surgery
Reviewed by: KC Madhusudhana
Apr/May 2012 (Vol 18 No 6)
 

Idiopathic epiretinal membrane (ERM) occurs in about 7% of the population. ERM results in various symptoms, such as metamorphopsia, reduced visual acuity and monocular diplopia. Surgical removal of ERM can improve vision in 70-80% of patients. Many prognostic factors for the visual outcome after ERM surgery have been investigated. Preoperative visual acuity and duration of the symptoms are known to be the most significant factors. However, the photoreceptor layer disruption could indicate the evidence of a long-standing or severe ERM. In this retrospective study, the authors evaluated the utility of preoperative optical coherence tomography (OCT) and multifocal electroretinogram (ERG) in predicting the visual outcome after ERM surgery. One hundred patients (100 eyes) with idiopathic ERM were included in the study (mean age, 63 years). Correlations between preoperative data (time-domain OCT and mfERG) and final best-corrected visual acuity (BCVA) were investigated. The preoperative OCT scan showed intact inner segment / outer segment (IS / OS) in 70.2% of eyes. Postoperatively, 77% of eyes achieved visual improvement by more than two Snellen lines. The integrity of the IS / OS junction and P1 implicit time on mfERG correlated significantly with the final BCVA (p=0.011 and 0.014 respectively). The final BCVA was significantly poorer in eyes with disrupted IS / OS junction. Mean final BCVA was 0.64 logMAR in the disrupted group and 0.07 in the intact group (P<0.001). The authors conclude that the photoreceptor disruption and P1 implicit time delay are significant predictors of poor visual recovery after ERM surgery. – KCM

Reference

Structural and functional predictors of visual outcome of epiretinal membrane surgery.
Kim JH, Kim MY, Chung EJ, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;153(1):103-10.e.1.

American Journal of Ophthalmology

Use of 20-MHz ultrasound in the management of traumatic cataract
Reviewed by: KC Madhusudhana
Apr/May 2012 (Vol 18 No 6)
 

Blunt and penetrating ocular trauma can lead to cataract formation. A good preoperative evaluation, particularly of the posterior capsule (PC), is necessary for optimal surgical management and to achieve satisfactory visual outcomes. However, slit-lamp biomicroscopic evaluation of posterior capsule may be hindered by associated ocular pathology such as corneal laceration, hyphema and swollen cortical lens matter. Conventional 10-MHz B-scan ultrasound has limited visualisation of the anterior segment structures. In this prospective study, the authors set out to investigate the accuracy of 20-MHz ultrasound for evaluation of the PC in traumatic cataract before surgery. Forty-three eyes (43 patients) with traumatic cataract were included in the study (mean age: 35.6 years, range: 4 to 68 years). In all cases, cataract was dense enough to prevent visualisation of the PC. Ultrasound B-scan was performed using a 20-MHz probe to detect any PC rupture. All patients subsequently underwent cataract extraction and intraoperative findings of the PC were compared with the preoperative ultrasound findings. The mode of trauma was blunt in four eyes and penetrating in 39 eyes. Two eyes had closed globe injury and 41 eyes had open globe injury. The posterior border of the lens was clearly visualised in all 43 eyes. Preoperatively, PC rupture was identified in 17 eyes (39.5%), while intraoperatively 14 eyes (32.6%) had PC rupture. Sensitivity, specificity, positive predictive value and negative predictive value were 93%, 86%, 76% and 96%, respectively, for 20-MHz ultrasound to detect PC rupture. The authors conclude that 20-MHz ultrasound is an accurate imaging tool for preoperative detection of PC rupture in traumatic cataract. Further studies are required to confirm these findings.

Reference

Evaluation of posterior capsule by 20-MHz ultrasound probe in traumatic cataract.
Tabatabaei A, Kiarudi MY, Ghassemi F, et al.
AMERICAN JOURNAL OF OPHTHALMOLOGY
2012;153(1):51-4.

British Journal of Ophthalmology

Midazolam and intraocular pressure in children
Reviewed by: Jonathan Chan
Apr/May 2012 (Vol 18 No 6)
 

This is a prospective observational study between the period of 2006 and 2007 of 72 eyes, in 36 cooperative children with normal eye examination requiring anaesthesia. The age range was between two and six years, with a mean age of 3.5 plus or minus 1.3 years and a body weight of 20kg. Four patients under the age of two were selected as well because of their eye cooperation during preoperative assessment. Intraocular pressure (IOP) measurements were performed before, and 15 and 30 minutes after sedation with oral midazolam (1mg/kg) given postoperatively. The intraocular pressures were measured again at five and 15 minutes after the induction of general anaesthesia. Generally anaesthesia was induced with propofol (3-4mg/kg) and remifentanil infusion (0.6µ/kg/min). Maintenance of anaesthesia was performed with remifentanil infusion and sevoflurane. After instillation of oxybuprocaine 4mg/mol and fluorescein (fluorescein-sodium, 1.7mg/mol) into the eye, the IOPs were measured three consecutive times in each eye using a Perkins tonometer. It was found that the mean IOP before sedation, and at 15 minutes and at 30 minutes after administration of midazolam, was not of statistical significance. The intraocular pressure was lowered at five and 15 minutes after induction of the general anaesthesia and was statistically significant (p<0.0001). It was found that in very young glaucoma patients (six months to two years old) applanation tonometry with Perkins tonometer was possible in only five out of the 35 examinations without sedation. After oral sedation with 1mg/kg midazolam, applanation tonometry was possible in all remaining 30 children without marked resistance. The authors conclude that midazolam sedation can be applied and is a well tolerated and safe method for IOP measurements in children.

Reference

The effects of midazolam on intraocular pressure in children during examination under sedation.
Oberacher-Velten I, Prasser C, Rochon J, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2011;95(8):1102-5.

British Journal of Ophthalmology

Severe idiopathic orbital inflammation
Reviewed by: Jonathan Chan
Apr/May 2012 (Vol 18 No 6)
 

This is a multicentre non-randomised retrospective study of patients with severe idiopathic orbital floor inflammation (IOI) treated with intravenous methylprednisolone (IVMP) plus oral prednisone (OP) therapy (IVMP+OP), compared to patients with IOI who were treated with only OP. During the period between 2000 and 2007, 95 patients were treated for IOI in the study. Forty patients were excluded from further analysis. Twenty-seven patients were included initially in the group with mild IOI and were further excluded subsequently. Only 15 patients were treated with OP-only and 12 patients were treated with IVMP+OP. It was found that patients treated with IVMP+OP had a shorter duration of symptoms, received more radiotherapy and had a shorter follow-up time, but that was not statistically significant. IVMP was given in doses of 100mgs in eight patients or 1000mgs in four patients for three consecutive days, or 500mgs every other day for a total of four administrations in one patient. IVMP therapy was followed by OP therapy. A second course of IVMP was administered until two weeks after pulse therapy (four patients). The authors concluded that there was no advantage of treating patients with severe IOI with IVMP+OP in terms of shortened treatment duration, lower cumulative dose or decrease in persistent symptoms. They suggest that the only indication for IVMP in this condition is limited, only for speeding symptom relief and recovery of the optic nerve dysfunction.

Reference

Treatment of severe idiopathic orbital inflammation with intravenous methylprednisolone.
Bijlsma WR, Paridaens D, Kalmann R.
BRITISH JOURNAL OF OPHTHALMOLOGY
2011;95(8):1068-71.

British Journal of Ophthalmology

Surgical correction for lower lid epiblepharon
Reviewed by: Jonathan Chan
Apr/May 2012 (Vol 18 No 6)
 

This is a retrospective study to determine the long-term effects of a new surgical technique for the correction of lower lid epiblepharon, using thermal contraction of the tarsus and lower lid retractor without lash rotating sutures. One hundred and twelve eyes of 56 patients had either a modified Hotz operation (group A) or a new surgical procedure (group B). Surgery was carried out between March 2005 and January 2008, and patients were followed up for more than three years. All the study patients underwent surgery conducted by a single surgeon. The inclusion criteria included that all the patients were under 15 years of age, with bilateral epiblepharon, no former history of lower lid surgery, and no combined surgery for epiblepharon. The new surgical technique requires thermal contraction using bipolar cautery applied to the inferior tarsus, including pretarsal orbicularis oculi muscle and lower lid retractors to create less rotation without additional rotating sutures. All operations were performed under general anaesthetic. Forty-four eyes underwent a modified Hotz operation (group A) and the 68 eyes underwent Lee’s thermal adjustable rotation of the lid margin technique (group B). After the mean follow-up period of 39.7 months, 65 eyes were successfully treated without recurrence and under-correction in group B. Mild recurrence developed in only three cases. Subjective symptoms disappeared in all patients in group B. Cilia loss was detected in two cases and wound dehiscence in one case in group B. In group A, one case of lid retraction and ectropion each developed. The demographics of the study population in both groups were similar. The authors claimed that the thermal contraction technique has severe advantages including: 1. The skin incision is made just below the last line, hence avoiding lower eyelid skin crease or visible scar; 2. Eyelid lashes are effectively rotated by thermal contraction, therefore avoiding the need for additional rotation sutures and suture related complications / problems; 3. The amount of rotation can be adjusted by the degree of thermal contraction, such as the power, duration and area involved; 4. Even in difficult cases, for example, severe ciliary touch, especially over the medial conjunctival area, this procedure is effective; 5. Minimal amounts of redundant skin and orbicularis muscle are removed to avoid the occurrence of ectropion or lower lid retraction.

Reference

Surgical correction for lower lid epiblepharon using thermal contraction of the tarsus and lower lid retractor without lash rotating sutures.
Chan M, Lee TS, Yoo E, Baek S.
BRITISH JOURNAL OF OPHTHALMOLOGY
2011;95(8):1675-8.

British Journal of Ophthalmology

Visual acuity after cataract surgery
Reviewed by: Jonathan Chan
Apr/May 2012 (Vol 18 No 6)
 

This is a prospective study conducted in Sidney, Australia between 2004 and 2007. The aim of the study was to assess the sustainability of visual acuity in the first two years after cataract surgery. The data of the vision was analysed in 1,809 patients at one month and 1,294 at subsequent postoperative visits. At the end of the two year period, 930 patients maintained the same pinhole vision level as they had at one month postoperatively (71.9%). One hundred and ninety-nine (15.4%) had an improvement and 165 (12.7%) had a reduction in pinhole vision. Of the 515 patients who dropped out with incomplete 24-month postoperative data, 101 (19.6%) had not yet reached their 24 months postoperative data. The remaining 414 patients included 100 (24.2%) who had died, 72 (17.4%) who withdrew due to health reasons, 54 (13.0%) who were no longer contactable, 35 (8.4%) who now lived too far away and 153 (37.0%) who declined to continue the study. Comparing patients with stable pinhole vision, those with a visual acuity reduction were more likely to be older (75 years), 59.4% vs. 49.6%), and to have any macular lesion (e.g. early age-related macular degeneration (AMD), macular laser or macular hole, 21.2% vs. 13.2%) preoperatively (all p≤0.02). All patients with reduced visual acuity at 24 month postoperative period, 21% (n=34) had early macular degeneration, 17% (n=28) had untreated posterior capsular opacification, 15% (n=25) had diabetic retinopathy and four patients had a branch retinal vein occlusion or macular tear telangiectasia. In conclusion, the authors found that 13-17% of a large cohort of cataract patients had lost at least two lines of their vision (presenting or pinhole) within the first two years following surgery, and 15-25% of patients had gained two or more lines of vision during the same period. The follow-up rate of 72% over a three year period is reasonable compared to other studies.

Reference

Sustainability of visual acuity in the first 2 years after cataract surgery.
Fong C S, Mitchell P, Rochtchina E, et al.
BRITISH JOURNAL OF OPHTHALMOLOGY
2011;95(8):1652-5.

Clinical and Experimental Ophthalmology

Ranibizumab therapy for CNV secondary to non-AMD
Reviewed by: Kwesi Amissah-Arthur
Apr/May 2012 (Vol 18 No 6)
 

The use of ranibizumab for the treatment of choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD) is well established and has been extensively documented. However, CNV occurs in other ocular conditions such as myopia, angiod streaks and multifocal choroiditis. This prospective case series on 41 patients over a twelve-month period aimed to determine the efficacy and safety profile in a non-AMD cohort of patients with CNV. Patients with a subfoveal lesion, no previous treatment for their CNV and without active inflammation were recruited. Patients were classified into three groups for purposes of analysis. The groups were myopia, multifocal choroiditis and other (a heterogeneous group due to the small numbers of constituent cases). The primary outcome measure was change in visual acuity (VA) and central macular thickness (CMT) measured from baseline to 12 months. Data were collected for 30 patients diagnosed with non-AMD associated CNV: 15 with myopia, seven with multifocal choroiditis and eight with other causes (peripapillary CNV – two, angioid streaks – two, central serous retinopathy – one, macular telangectasia – one, and idiopathic CNV – two). Approximately one quarter of participants were male, and the mean age for the cohort was 54 (range 25-86). The average number of injections in 12 months was 4.2 for the entire group. On average, 40%, 43% and 25% of patients with myopia, multifocal choroiditis and ‘other’ pathologies, respectively, experienced a three or more line improvement in vision. Central macular thickness significantly decreased in the 12-month period for the combined group (P=0.03). No patient had an adverse systemic side-effect; however, there was one case of endophthalmitis (Streptococcus salivarius). The authors accept their limitation of small sample size and the fact that there was no statistical significance in the findings of visual acuity from baseline to twelve-months, they then go on to say that ranibizumab is an effective therapy for both stabilising and remediating vision loss because of CNV from pathology other than AMD. This paper by Tourtbeck et al. attempts to assess the use of ranibizumab therapy for CNV secondary to non-age-related macular degeneration causes, the paper appears to show an improvement in visual acuity, though it is not statistically significant. Although the authors claim that ranibizumab is an effective therapy for stabilising vision loss, given the small numbers of cases and the heterogeneity of these cases, it is difficult for one to draw such a strong conclusion from this particular piece of work.

Reference

Ranibizumab therapy for choroidal neovascularization secondary to non-age-related macular degeneration causes.
Troutbeck R, Bunting R, van Heerdon A, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2011;40(1):67–72.

Cornea

Elevated intraocular PISK
Reviewed by: Sharmina Khan
Apr/May 2012 (Vol 18 No 6)
 

Pressure-induced interlamellar stromal keratitis (PISK) was first described by Belin in 2002 and is a type of interface haze and oedema occurring several weeks to months after laser in-situ keratomileusis (LASIK) associated with significantly elevated pressures. The authors report a case of a 30-year-old man presenting with redness, retrobulbar pressure, photophobia and blurred vision of the right eye. His visual acuities were right eye (RE) 20/30 corrected and left (LE) 20/20 corrected. His visual acuities were RE 20/200 corrected and LE 20/20 corrected, intraocular pressure right 31mmHg and left 13mmHg. There was significant increase in corneal haze limited to the anterior stroma within the LASIK flap. There were also three inferior epithelial cysts, no interface fluid, discrete infiltrates or epithelial defects. The flap was intact and in position. There was a marked anterior chamber inflammation and keratic precipitates. He was treated with a topical steroid and an IOP lowering agent. One month later his IOP was reduced, the flap clear and intraocular inflammation resolved. He was referred to a rheumatologist who diagnosed HLA-B27 negative spondyloarthropathy. This case of hypertensive uveitis with secondary flap haze is not typical of previously described PISK by RJ Smith et al. in 1998 and Belin MW in 2002, where the cases of raised IOP occur in the absence of intraocular inflammation. PISK has been described as flap haze that worsens with topical steroid and associated with a brisk rise in IOP. The mechanism of raised IOP in PISK has not been elucidated. It is suggested that it is due to fluid-dynamic malfunction leading to corneal oedema and interface haze. Histopathological evidence that oedema can occur preferentially at central and paracentral wounds because they contain proteoglycans that absorb water. Several authors have reported fluid at the interface leading to an oedematous flap which is visible on confocal microscopy. Unlike diffuse lamellar keratitis it is not associated with inflammation. PISK can occur many years after LASIK, when it is assumed that the LASIK flap would be adherent to the underlying stroma but in fact there is a potential space that can accumulate with fluid in the presence of raised IOP.

Reference

Elevated intraocular pressure-induced interlamellar stromal keratitis occurring 9 years after laser in situ keratomileusis.
Lee V, Sulewski ME, Zaidi A, et al.
CORNEA
2012;31(1):87-9.

Current Eye Research

Corneal cross-linking without removal of the corneal epithelium
Reviewed by: Badrul Hassain
Apr/May 2012 (Vol 18 No 6)
 

Corneal collagen cross-linking is a newly accepted method for treating progressive keratoconus and ectatic corneal disease. Standard treatment includes debridement of the central corneal epithelium and subsequent instillation of 0.1% riboflavin solution every three minutes for 30 minutes prior to ultraviolet-A irradiation, whilst riboflavin continues to be instilled. Photo-oxidative induction of collagen cross-links stiffens the upper 200-300µm of corneal stroma. The most significant barrier to riboflavin permeability is the corneal epithelium, with its tight junctions. Epithelial debridement results in pain and is associated with risk of corneal infections. Therefore, some surgeons modify the standard protocol and perform the treatment without epithelial debridement, by using various drops containing benzalkonium (BAC), Ethylenediaminetetraacetic acid (EDTA) or Ribomycin drops containg gentamicin, EDTA and BAC. This study investigated the influence of osmolarity on the transepithelial permeability of riboflavin solutions in a cross-linking procedure on 36 cadveric rabbit eyes. The eyes were divided into six groups of six eyes, one group serving as the control group had the standard treatment protocol following epithelial removal. Various solutions were applied for 30 minutes to the remaining five groups: A: riboflavin 0.1% in NaCl 0.9%; B: riboflavin 0.1% in NaCl 0.44% with 0.02% BAC; C: riboflavin 0.1% in NaCl 0.44% with 0.01% BAC; D: riboflavin 0.1% in NaCl 0.44% without BAC; E: riboflavin 0.1% in NaCl 0.9% with 0.02% BAC; and F: riboflavin 0.1% in NaCl 0.9% without BAC. Corneal thickness was measured by ultrasound pachymetry. The absorption coefficient (AC) of the stroma alone was calculated by measuring the thickness and transmitted UV intensity. As expected, the control group showed the highest AC and this was significantly different to all the other groups. There is a large difference in the transepithelial penetration of riboflavin 0.1% with BAC 0.02% solutions that contain different NaCl concentrations. The AC differed by more than a factor of two (p=0.004). No statistically significant difference was found between riboflavin 0.1% in NaCl 0.44% containing BAC 0.02% and BAC 0.01%. Compared to the control group, these solutions resulted in an AC of 37% and 33% respectively. The authors conclude the paper by suggesting what should be in transepithelial riboflavin solution: 0.01% BAC and 0.44 % NaCl to increase the permeability of the epithelium, but should exclude dextran as it inhibits paracellular transport. Further investigations are needed to detect a real clinical effect and possible endothelial damage.

Reference

Riboflavin osmolar modification for transepithelial corneal cross-linking.
Raiskup F, Pinelli R, Spoerl E.
CURRENT EYE RESEARCH
2012;37(3):234-8.

Current Eye Research

High speed projectile impacts and risk of eye injuries
Reviewed by: Badrul Hussain
Apr/May 2012 (Vol 18 No 6)
 

Previous studies have used intraocular pressure (IOP) to determine the rupture pressure of the human eye. High rate pressurisation resulted in a mean rupture pressure of 7275±2175 mmHg. Although studies have reported the injury risk of projectile impacts, none have reported the corresponding IOP. This study provides pressure results for the most severe eye injuries. Blunt impacts, using a pneumatic cannon, to twelve porcine eyes were performed using a custom impact system designed and built to determine IOP. Projectiles used in the tests included a 6.35mm diameter metal ball, a 9.25mm aluminium rod and an 11.16mm diameter aluminium rod. The IOP was measured using a small pressure sensor inserted through the optic nerve. In total, 36 tests were performed with a range of velocities between 6.2 m/s and 66.5 m/s. The range of IOP measured between 2017mmHg and 26426 mmHg. Normalised energy levels (the kinetic energy divided by the cross-sectional area of the object) varied between 1016.2 J/m2 and 71262.2 J/m2. Four tests resulted in globe rupture. A strong nonlinear correlation between IOP and kinetic energy was observed for all tests (R2=0.88). A weaker nonlinear correlation between IOP and normalised energy was observed for all tests (R2=0.52). When separated by projectile type, there is a higher correlation between IOP and normalised energy for both cylinders. The velocities tested in this study are within the range of consumer products greater than velocities from dart guns and below those from paintball guns. The authors acknowledge some of the limitations of using a porcine eye, but feel it is a reasonable surrogate. They also acknowledge the limitation of using cadaveric tissue, but look forward to future work that may include an eye that has vascular pressure in order to study the specific effects related to chronic ocular injuries. They conclude by stating that results from this study can provide foundation data for the design of safe consumer products. The correlations found between IOP, kinetic and normalised energy have the potential to be used in computational models of the eye and the development of instrumented synthetic eyes for an advanced anthropomorphic head that can measure IOP during impacts

Reference

Evaluating the risk of eye injuries: intraocular pressure during high speed projectile impacts.
Duma SM, Bisplinghoff JA, Senge DM, et al.
CURRENT EYE RESEARCH
2012;37(1):43-9.

Experimental Eye Research

Protective effect of MR antagonism in ischaemic retinal injury
Reviewed by: Graham Wallace
Apr/May 2012 (Vol 18 No 6)
 

The renin-angiotensin-aldosterone system (RAAS) contributes to the control of blood pressure and electrolyte homeostasis. A renin-angiotensin pathway has also been found in the eye and local production of these molecules and the antigotensin converting enzyme (ACE) has been demonstrated. Aldosterone is a steroid hormone that acts via the mineralocortocoid receptor (MR) and is released in response to angiotensin. In this study, the effect of MR antagonism of the MR in ischaemic-reperfusion injury in the rat retina was addressed. Retinal ischaemia was induced by raised intraocular pressure due to saline infusion. Pretreatment with an angiotensin receptor (AR) antagonist or an MR antagonist, either alone or together significantly reduced retinal ischaemic injury. No protective effect was seen when aldosterone and AR antagonist were given together. When aldosterone was given alone in the absence of ischaemia retinal thickness was unaffected but retinal ganglion cells were lost. These results show that the protective effect of AR or MR antagonism is inhibited by aldosterone. Therefore, the retina has a local aldosterone / MR pathway and MR blockade may be beneficial in ischaemic retinal conditions.

Reference

Activation of the aldosterone/mineralocorticoid receptor system and protective effects of mineralocorticoid receptor antagonism in retinal ischemia-reperfusion injury.
Liu Y, Hirooka K, Nishiyama A, et al.
EXPERIMENTAL EYE RESEARCH
2012;96(1):116-23.

Experimental Eye Research

Targeting costimulatory molecules to control uveal melanoma
Reviewed by: Graham Wallace
Apr/May 2012 (Vol 18 No 6)
 

Uveal melanoma is the most common primary intraocular malignant tumour in adults and while growth is controlled by treatment fatal metastases are often the outcome. The need for new treatment, options has concentrated on immunotherapy to induce the immune system to recognise and destroy the tumour. Costimulatory molecules amplify the response when expressed on immune cells. To address whether the costimulatory molecules CD40 and B7-H1 were involved in the response to melanoma cells, primary tumour cells and cell lines were analysed. B7-H1 was detected on all cells tested and was upregulated on treatment with the cytokine interferon-γ. Blocking B7-H1 with an antibody augmented IL-2 production by T lymphocytes cocultured with uveal melanoma cells stimulated with IFNγ. CD40 was constitutively expressed on melanoma cells and increased on treatment with IFNγ. Recombinant CD40 ligand increased production of chemokines by melanoma cells. These results suggest a complex interplay between immune and melanoma cells. Stimulation through CD40 will attract cells to the site of tumour via chemokines, but the efficacy may be inhibited by B7-H1 expressed on the melanoma cells as indicated by reduced IL-2 production. It should be noted that reduced IL-2 may lead to a reduced T regulatory response and therefore may support the response against the melanoma. Together this work shows that targeting costimulatory molecules of the immune response may be beneficial in uveal melanoma.

Reference

Costimulatory molecule expression on human uveal melanoma cells: functional analysis of CD40 and B7-H1.
Ma J, Usui Y, Kezuka T, et al.
EXPERIMENTAL EYE RESEARCH
2012;96(1):98-106.

Eye

Participation in clinical trials
Reviewed by: John Brookes
Apr/May 2012 (Vol 18 No 6)
 

The difficulty in recruiting patients to participate in clinical trials has always been problematic and is well documented. It has been suggested that around 50% of clinical trials fail to reach their recruitment target or require extension. The aim of the present study was to examine the attitudes of patients presenting with advanced glaucoma in participating in a randomised trial comparing medical with primary surgical treatment. A significant proportion of patients present with advanced glaucoma, which is a risk factor for blindness. Previous studies and NICE guidelines have recommended that patients who present with advanced glaucoma should be offered primary glaucoma surgery. Group interviews were conducted by qualitative researchers and a clinician. The outcome of the discussions was based around the extent of patients’ knowledge, their anxieties about surgery and concerns about compromised care due to trial involvement. The authors concluded that patients’ willingness to participate in randomised clinical studies is significantly connected to their level of comprehension and insight about the medical condition, its treatment and the research process and misunderstanding about any of these aspects may act as a significant barrier to trial recruitment. The authors suggest that recruitment rates for future trials could be enhanced by ensuring patients have full and accurate information about the treatment alternatives and reassurance about the research process, and emphasising that randomisation will not compromise clinical care. Looking at patients’ perceptions in this kind of qualitative analysis is highly relevant and understanding their concerns will not only help recruitment in clinical trials but will also enhance their clinical care overall.

Reference

The willingness of patients presenting with advanced glaucoma to participate in a trial comparing primary medical vs primary surgical treatment.
Leighton P, Lonsdale AJ, Tildsley J, King AJ.
EYE
2012;26(2):300-6.

Journal of Pediatric Ophthalmology and Strabismus

Change in angle from GA to postop day one
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

the end of surgery under general anaesthesia with strabismus angles on postoperative day one with respect to the type of surgery. The purpose was to improve surgical predictability in exotropia surgery. Seventy-eight patients had their angle assessed by Hirschberg test. Patients who underwent lateral rectus recession showed approximately 10PD of postoperative convergence and those who underwent medial rectus resection showed much less postoperative convergence and a tendency to remain at the same angle at day one as at the end of surgery under general anaesthesia.

Reference

Postoperative convergence after recovery from general anesthesia in exotropia surgery.
Ha S, Kim S-H.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(5):305-10.

Journal of Pediatric Ophthalmology and Strabismus

Doctor etiquette
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

The authors report a survey of expressed preferences of families visiting a paediatric ophthalmologist for the first time. Parents and guardians were asked to complete an open and closed ended questionnaire. One hundred and forty-nine surveys were completed. The results suggest that parents wish physicians to wear white coats and business casual attire in clinic, greet with a handshake and address parents informally such as Mum / Dad.

Reference

An evidence based approach to physician etiquette in pediatric ophthalmology.
Reddy A, Coats D, Yen K.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(6):336-9.

Journal of Pediatric Ophthalmology and Strabismus

fMRI changes in nystagmus
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

Functional magnetic resonance imaging (fMRI) was used to localise the anatomic correlates for infantile nystagmus syndrome (INS). Changes in neuronal activity were correlated as a result of eye movements or nystagmus. The study used a null zone fMRI technique and presents preliminary data of site validity for uncovering the ocular motor circuitry of INS. The data reveal that the declive of the cerebellum is related to the nystagmus associated with INS.

Reference

Neural circuit involved in idiopathic infantile nystagmus syndrome based on functional MRI.
Leguire LE, Kashou NH, Fogt N, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(6):347-56.

Journal of Pediatric Ophthalmology and Strabismus

ROP follow-up
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

Discussion centred on long-term follow-up of children with stage one or two retinopathy of prematurity (ROP). Generally follow-up was recommended every two weeks until 40 weeks postmenstrual age. Refraction was typically at a follow-up examination where a speculum is not required but not during the acute ROP examinations – usually at three to four months. Treatment of refractive error is generally the same as for term babies. The authors discussed refractive follow-up for infants requiring laser treatment with refraction on follow-up combined with checks for risk factors from laser treatment such as myopia, cataract and retinal detachment

Reference

Long-term follow-up in patients with retinopathy of prematurity.
Panelists: Chiang MF, Lichtenstein SJ, Reynolds JD.
Moderator: Wagner RS.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(6):328-32.

Ophthalmology

Endothelial cell count after DSAEK rejection
Reviewed by: Nathaniel Know Cartwright
Apr/May 2012 (Vol 18 No 6)
 

Corneal graft rejection has been studied comprehensively following penetrating keratoplasty and is well recognised as one of the leading causes of graft failure. Less information is available on the consequences of this complication of endothelial keratoplasty. In this single-centre retrospective analysis 615 eyes of 415 patients undergoing Descemet stripping automated endothelial keratoplasty (DSAEK) were studied. All were followed up for at least six months. Endothelial cell counts were recorded by specular microscopy preoperatively and six and 12 months postoperatively then annually thereafter. Graft rejection was defined as findings of keratic precipitates with or without corneal oedema, or anterior chamber cell and flare with or without corneal oedema after the initial resolution of perioperative inflammation. The percentages of endothelial cell loss recorded at one, two, three and four years were compared between eyes with and without rejection episodes using the Mann-Whitney U test. Forty-five (7.3%) cases of graft rejection occurred, most often between 12 and 18 months postoperatively as topical steroid drops were weaned. After a graft rejection episode median percentage decline in endothelial cell count was higher than in eyes not affected by rejection, a finding statistically significant two and three years postoperatively. These results lead the authors to suggest that patients undergoing DSAEK for Fuchs dystrophy should remain on long-term steroid drops, a practice already observed by many.

Reference

Graft rejection after descemet’s stripping automated endothelial keratoplasty: graft survival and endothelial cell loss.
Li JY, Terry MA, Goshe J, et al.
OPHTHALMOLOGY
2012;119(1):90-4.

Ophthalmology

Treatment of anterior scleritis
Reviewed by: Nathaniel Knox Cartwright
Apr/May 2012 (Vol 18 No 6)
 

Scleritis is a painful and potentially blinding disease process that is sometimes associated with very significant systemic copathology. This retrospective case note review set out to determine the factors associated with a successful response to treatment of non-infectious anterior scleritis. Three hundred and ninety-two patients from two centres were studied. Treatments used included non-steroidal anti-inflammatory drugs (NSAIDs; 36.7%), steroids (7.4%), immunosuppressive drugs (34%) and biologic agents (14.3%). A response to NSAIDs was associated with idiopathic or nodular scleritis with a low degree of scleral inflammation or without ocular complications. Steroids were effective for idiopathic diffuse or nodular scleritis accompanied by a high degree of scleral inflammation. Immunosuppressive drugs were effective for diffuse or nodular scleritis with associated systemic disease and for necrotising scleritis. Biologic agents were also effective for diffuse or nodular scleritis with associated systemic disease. The authors propose treatment guidelines based on their findings which, whilst intuitive, are a useful encapsulation of the principles underlying the treatment of not just scleritis but also other ocular inflammatory conditions.

Reference

Scleritis therapy.
Sainz de la Maza M, Molina N, Gonzalez-Gonzalez LA, et al.
OPHTHALMOLOGY
2012;119(1):51-8.

Ophthalmology

Unexpected resolution of corneal oedema
Reviewed by: Nathaniel Knox Cartwright
Apr/May 2012 (Vol 18 No 6)
 

This surprising case report describes how corneal oedema cleared following Descemet membrane stripping without replacement. The patient was a 34-year-old Caucasian female affected by both Fuchs endothelial dystrophy and posterior polymorphous membrane dystrophy (PPMD). Initially, a right-sided Descemet’s stripping endothelial keratoplasty (DSEK) was undertaken, but this was complicated by primary graft failure. A repeat DSEK was performed but gradual and delayed graft dislocation occurred. During this time there was a negative correlation between graft attachment and corneal clarity, so it was eventually decided to remove the donor lenticule without replacement. Despite this, the central cornea cleared and endothelial cell repopulation was confirmed in this area using confocal microscopy. On the basis of this outcome the decision was made to perform left Descemet’s stripping without transplantation that resulted in resolution of corneal oedema in this eye too. It would appear that this unexpected outcome was a consequence of central migration of peripheral endothelial cells, possibly facilitated by the codiagnosis of PPMD.

Reference

Spontaneous corneal clearing after Descemet’s stripping without endothelial replacement.
Shah RA, Randleman JB, Grossniklaus H.
OPHTHALMOLOGY
2012;119(2):256–60.

Orbit

An orbital decompression technique
Reviewed by: Konal Saha
Apr/May 2012 (Vol 18 No 6)
 

The authors describe an ab externo approach to lateral wall orbital decompression surgery and present their results when used in 21 cases of thyroid associated orbitopathy. They describe exposure of the lateral orbital rim through a horizontal incision posterior to the lateral canthus, reflection of the temporalis muscle laterally to reveal the outer aspect of the lateral orbital wall then creation of a large fenestration into the orbit. They report impressive reduction in proptosis (median 5mm). The authors state an extensive lateral wall decompression is perhaps more readily achieved through the external approach they describe, however, concede other authors have published similar results when approaching the decompression from within the orbit (1). Temporal hollowing has been noted to be a problem following this approach, which is commonly used in lateral orbitotomy. The authors note their follow-up period was not long enough to comment on whether this was a problem in this group of patients. An advantage of the ab externo over the the ab interno approach not mentioned is limiting the amount of retraction on the globe which may be useful in those patients where globe integrity may be compromised, e.g. previous penetrating keratoplasty, trabeculectomy, corneal thinning. In summary, the paper describes an approach to lateral orbital decompression which has proved safe and effective.

Reference

Outcome of deep lateral wall rim-sparing orbital decompression in thyroid-associated orbitopathy: a new technique and results of a case series.
Mehta P, Durrani OM.
ORBIT
2011;30(6):265-8.

Retina

Bevacizumab vs. bevacizumab and triamcinolone for neovascular AMD
Reviewed by: Nikolaos D. Georgakarakos 
Apr/May 2012 (Vol 18 No 6)
 

The purpose of this prospective randomised clinical trial performed at two centres is to determine whether combined intravitreal bevacizumab (IVB 1.25mg) and triamcinolone (IVT 2mg) is more effective than IVB alone in neovascular age-related macular degeneration (AMD). The randomised clinical trial was conducted to compare the efficacy of three consecutive intravitreal injections of IVB in eligible eyes with that of the same regimen combined with IVT during the initial injection. The three injections were used in a mandated fashion and retreatment with bevacizumab was only performed if necessary. Exclusion criteria were presence of diabetic retinopathy, glaucoma, or any other macular disease and previous history of treatments (except of photodynamic therapy). Inclusion criteria were all types of subfoveal choroidal neovascularisation (CNV) secondary to AMD. The primary outcome measure was change in best corrected visual acuity (BCVA), the second was change in central macular thickness (CMT), need for a fourth injection and adverse effects (retinal pigment epithelial tear, submacular haemorrhage, elevation of intraocular pressure, endophthalmitis). Sixty eyes were assigned to the IVB group and 55 to the IVB / IVT. BCVA and CMT were measured at six, 12, 18, and 24 weeks. One hundred and twenty eyes were included and were randomised to the treatments. Masking was also achieved by a masked optometrist to the groups, who performed visual acuity and optical coherence tomography (OCT). The statistician who performed the analysis was also masked. Chi-square, fisher extract and Mann-Whitney tests were used to compare changes between and within groups at different time intervals compared with baseline. P values <0.05 were considered statistically significant. Statistical analysis was performed using SPSS software. Mandated therapy with IVB improved BCVA and decreased CMT in neovascular AMD. The addition of low dose IVT temporarily increased the efficacy in the early post-injection period and resulted in fewer requirements for repeat injections at six months. The need for retreatment at week 24 was different in the two groups (in favour of the IVB / IVT group): 32 eyes (53.3%) in the IVB group versus 19 eyes (34.5%) in the IVB / IVT group required a fourth injection. Improvement of BCVA at six, 12, 18 and 24 weeks was statistically significant in both groups compared to baseline. At weeks six and 12 there was more visual improvement in the IVB / IVT group but no statistically significant difference in weeks 18 and 24. There was a statistically significant difference in CMT reduction at weeks six, 12, 18, 24 compared to baseline for both groups but no difference between the groups. Repeating IVT injections may improve the durability of its beneficial effects but this may increase the risk of ocular hypertension and cataract. The limited duration of the study (six months) precludes drawing a definite conclusion regarding the cataractogenic effect of IVT. A further study is required to evaluate the long-term effects of such a combination therapy. The short-term benefits of combination therapy may not justify the addition of IVT to IVB since the visual improvement at 24 weeks was not different between the two groups.

Reference

Intravitreal bevacizumab versus combined intravitreal bevacizumab and triamcinolone for neovascular age-related macular degeneration. Six-month results of a randomised clinical trial.
Ahmadieh H, Taei R, Riazi-Esfafani M, et al.
RETINA
2011;31(9):1819-26.

Retina

Surgical treatment of lamellar macular hole
Reviewed by: Nikolaos D. Georgakarakos 
Apr/May 2012 (Vol 18 No 6)
 

This retrospective study reviewed the surgical treatment outcomes in 44 patients (45 eyes). The patients underwent a 23g or 20g pars plana vitrectomy with epiretinal membrane (ERM) and internal limiting membrane (ILM) peel with or without air or 20% SF6 gas (no tamponade was used in two cases). Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuities were converted to logarithm of the minimum angle for resolution and non parametric Wilcoxon test and linear regression was performed. Postoperative follow-up period varied from one month to 73 months (mean 18 months). Post operative prone posturing (avoidance of supine position) varied from 12 hours to six days. Retrospective analysis showed that the duration of posturing was intuitively increased for larger lamellar holes and less for smaller ones. The difference of preop and postoperative visual acuities was statistically significant (p<0.0001). Ninety-three percent had a final visual acuity of 20/40 or better and visual acuity gain was directly correlated with preoperative visual acuity (p<0.0001). It was not correlated with any of the following parameters: age, gender, largest lamellar macular hole (LMH) diameter, foveal thickness at the base of the hole, presence or absence of posterior vitreous detachment (PVD), type of tamponade used, duration of prone positioning, pseudophakia or duration of follow-up. Cataract surgery was performed in 53% of the eyes in the postoperative period. The authors recommend surgery for LMH based on their results, not only to avoid further vision loss but also to improve vision in a significant manner. However, the retrospective nature, the small number of patients and the absence of randomisation or comparison in this study are important limitations. So far there is little evidence of the prognostic factors that determine postoperative surgical success in ERM peel (with or without LMH). Nevertheless, until such studies are published, the encouraging results and findings of previous interventional studies support the idea that surgery for LMH may be beneficial.

Reference

Surgical treatment of lamellar macular hole associated with epimacular membrane.
Casparis H, Bovey E.
RETINA
2011;31(9):1783-90.

Strabismus

Adult amblyopia therapy
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

The authors review variations between visual acuity and contrast sensitivity in individuals with amblyopia in order to characterise the pattern of learned improvements and generalisation in adult amblyopic subjects. They consider whether learned improvements in monocular visual function provide a platform from which abnormal binocular function can be ameliorated. The research suggests that in many adults with amblyopia, it is possible to restore several aspects of visual function using perceptual learning.

Reference

Can human amblyopia be treated in adulthood?
Astle AT, McGraw PV, Webb BS.
STRABISMUS
2011;19(3):99-109.

Strabismus

Amblyopia and daily tasks
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

This review considers studies of eye-hand coordination, walking, driving and reading skills which have formed the bulk of basic research on effect of amblyopia on daily-encountered real-world tasks and evaluate the impairments that children or adults with amblyopia exhibit in such tasks. The authors conclude that even though impairments on each task may only represent a minor disability, impairments were present on every task and this could cumulatively impact detrimentally on activities of daily living. Cautious behaviour may be noted along with failure to achieve normal levels of accuracy on tasks.

Reference

Amblyopia and real-world visuomotor tasks.
Grant S, Moseley MJ.
STRABISMUS
2011;19(3):119-28.

Strabismus

Amblyopia update
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

This update considers the following issues: who benefits from optical treatment, patching versus atropine, is there an optimum patching regime, how does compliance affect success, can education enhance compliance / concordance with treatment, is there an optimum age for treatment? The authors review the findings of trials of mainstay amblyopia treatment conducted within the past five years. They confirm that optical treatment (refractive adaptation) is beneficial to all types of amblyopia, that weekend atropine is as effective as daily, that weekend atropine is as effective as six-hour daily patching for severe amblyopia, that older children (>6 years) require a greater occlusion dose per day than younger children, and that interventions such as cartoons, written and video explanations of treatment aid those who would otherwise have poor compliance or drop out from treatment.

Reference

Amblyopia therapy: an update.
Stewart CE, Moseley MJ, Fielder AR.
STRABISMUS
2011;19(3):91-8.

Strabismus

Binocularlty restoration in amblyopia
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

Research on quantification of suppression in amblyopia is reviewed, providing artificial viewing conditions to enable binocular combination and development of binocularly based treatment of amblyopia in which suppression imbalance is measured and treated as a first step. The authors highlight recent developments that allow this new treatment approach to be easily adapted for clinical use. Prolonged periods of binocular combination lead to a strengthening of binocular vision in strabismic amblyopies and eventual combination of binocular information under natural viewing conditions.

Reference

Restoration of binocular vision in amvblyopia.
Hess RF, Mansouri B, Thompson B.
STRABISMUS
2011;19(3):110-8.

Strabismus

Globe perforation survey
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

The purpose was to investigate the management of suspected globe perforation during strabismus surgery in the UK. A postal survey of consultant ophthalmologists was circulated with 57.7% (n=517) returned. Forty-six percent of respondents performed strabismus surgery; 40.8% previously suspected a globe perforation and most (88%) subsequently performed dilated examination of the fundus. Most treated the lesion themselves: a few referred to a vitreoretinal specialist. Treatment was with cryopexy, laser retinopexy, observation and antibiotics. Six cases of sight-threatening complications were reported including postoperative endophthalmitis, retinal detachment, chorioretinal scarring and suprachoroidal haemorrhage.

Reference

A survey of the management of globe perforation during strabismus surgery in the UK.
Rathod D, Goyd R, Watts P.
STRABISMUS
2011;19(2):63-6.

Strabismus

Manneristic behaviours
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

This literature review focuses on the amnenristic behaviours exhibited by visually impaired children. The purpose was to determine what these behaviours are and provide reasoning as to why they occur, indicating any association between the behaviours and the severity of visual impairment, age and ability of the child. The review considers the varying definitions of manneristic behaviours, aetiology of these, the degree of visual impairment versus type of mannerism and the influence of additional impairments, prevalence and management.

Reference

Manneristic behaviours of visually impaired children.
Molloy A, Rowe FJ.
STRABISMUS
2011;19(3):77-84.

Strabismus

Prevention and treatment of amblyopia
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

This review focuses on strategies to prevent or reverse the effects of monocular deprivation and amblyopia. It considers the effects of mixed daily visual experience on visual acuity and cortical function. The authors conclude that research has conclusively shown that, depending on the age of the child, three to six hours of daily patching wear on average are sufficient to attain the maximum possible improvement. The remaining daily binocular visual exposure will be long enough to ensure that little detriment to the acuity of the patched eye will be incurred. The authors acknowledge that stereopsis is more susceptible to disruption by occlusion.

Reference

Experimental models of amblyopia: insights for prevention and treatment.
Sengpiel F.
STRABISMUS
2011;19(3):87-90.

Strabismus

Tisseel fibrin glue
Reviewed by: Fiona Rowe
Apr/May 2012 (Vol 18 No 6)
 

In this study, the clinical outcomes of conjunctival closure with fibrin glue (Tisseel) were compared with the results of conventional conjunctival closure in regard to redness, watering, pain and discomfort in eyes in the early postoperative course of strabismus surgery. Tisseel was a higher cost than 7/0 vicryl suture but found to cause less irritation and less inflammation.

Reference

Tissue adhesives as an alternative for conjunctival closure in strabismus surgeries.
Basmak H, Gursoy H, Cakmak AI, et al.
STRABISMUS
2011;19(2):59-62.

Clinical and Experimental Ophthalmology

Enter the reverend: introduction to and application of Bayes’ theorem in clinical ophthalmology
Reviewed by: Kwesi Amissah-Arthur
Feb/Mar 2012 (Vol 18 No 5)
 

The application of statistics to medicine has made the inference of a p-value from data the de-facto way that studies are analysed and reported. The first thing that many of us do is to quickly look at the results section to see if there is any statistical significance. However, the practice of medicine is not always predicated by whether there is statistical significance but whether there is a certain evidence-based ‘degree of belief’ attributed to the probability of an outcome, which should be modified when there is any new evidence. In this article by Thomas et al. they seek to introduce the concept of Bayes’ theorem and use examples to demonstrate how it can be used to provide valuable clinical information to the practicing ophthalmologist. The authors work through the use of two-by-two tables to calculate sensitivity, specificity, positive and negative predictive values and joint probabilities, as well as conditional probabilities. The authors then apply Bayes’ theorem to firstly diagnostic testing, and then to the risk of pupillary block in a diabetic undergoing cataract surgery. The development of angle closure glaucoma in a primary angle closure suspect is also tackled, as is initiating medical treatment for glaucoma, i.e. the probability that an observed decrease in intraocular pressure is due to the medication that has been started. Thomas et al. demonstrate the futility of testing when prior probability of disease is low. They state that, in the diagnostic arena, Bayes’ theorem starkly highlights the gulf between clinical practice and screening with regards to the use of stand-alone technology and improves our ability to utilise ancillary tests in a sensible manner. The main proviso with respect to Bayes’ theorem is to be aware that the clinical utility of Bayes’ theorem is dependent on a knowledge of and access to relevant valid literature. In the absence of such information, some of the data can be obtained by expert consensus, with the caveat that the result will only be a guideline, subject to change with accumulation of more valid data. In this paper the authors introduce the reader to the concept of Bayesian theory and illustrate its usefulness in understanding clinical application of investigations. I would entreat everyone to read the paper.

Reference

Enter the reverend: introduction to and application of Bayes’ theorem in clinical ophthalmology.
Thomas R, Mengersen K, Parikh RS, et al.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2011;39(9):865–70.

Clinical and Experimental Ophthalmology

Safety profile of anterior chamber paracentesis performed at the slit lamp.
Reviewed by: Kwesi Amissah-Arthur
Feb/Mar 2012 (Vol 18 No 5)
 

The use of the aqueous humour gained through anterior chamber (AC) paracentesis is a valuable tool in the management of uveitis. The authors of this retrospective observational case series from a single tertiary centre evaluated the safety profile of AC paracentesis performed when patients were sitting at a slit-lamp as an outpatient procedure. The technique described involves using a 27-gauge fixed-needle tuberculin syringe that is inserted at the paralimbal clear cornea in a plane above and parallel to the iris with the bevel of the needle facing forward until the whole bevel penetrates the cornea. Under direct vision, the sampler holds the syringe between the thumb and middle fingers and the index finger is used to pull the plunger to aspirate the aqueous. The O’Rourke pipette was also used in this study; it consists of a short 30-gauge needle mounted inside plastic tubing, which in turn is connected to a soft polyethylene suction-infusion bulb. The bulb is squeezed to create a vacuum and the needle inserted at the limbus as described above. When pressure of the bulb is released, aqueous spontaneously fills the pipette. Between 1997 and 2009 the authors performed anterior chamber paracentesis in 560 patients. A tuberculin syringe was used in 510 cases and a pipette was used in 50 cases. There were four complications (0.7%). Two patients had inadvertent injection of sterile air into the anterior chamber but with spontaneous resolution and no adverse outcome (O’Rourke pipette for both). One patient had anterior lens capsule touch that was self-sealing and left a tiny localised opacity (tuberculin syringe). One patient had an allergic reaction to povidone iodine. No patients reported pain, and there were no cases of iris trauma, entry site leak, hypotony, hyphaema or endophthalmitis. This series is the largest to document the use of an AC paracentesis in any context. The study was, however, not designed to compare slit-lamp based AC paracentesis to supine operating theatre based paracentesis. Given the very low rate of complications in this series it is appropriate to consider the use of this technique in outpatients. However, the authors recognise that to determine the precise incidence of lens-touch or of other rare potential complications, such as endophthalmitis, an even larger cohort would be required. The authors conclude by stating that where there is a suspected infectious aetiology the ability to quickly and easily obtain a sample of aqueous humour is of vital importance as rapid diagnosis and treatment may prevent serious sight-threatening consequences. They add that their method is quick, requires minimal preparation time and can be performed safely as an outpatient procedure at the slit-lamp following adequate aseptic precaution, and appropriate counselling.

Reference

Safety profile of anterior chamber paracentesis performed at the slit-lamp.
Trivedi D, Denniston AKO, Murray PI.
CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2011;39(8):725–8.

Cornea

“Swiss Roll” Amniotic Membrane Technique for the Management of Corneal Perforations.
Reviewed by: Sharmina Khan
Feb/Mar 2012 (Vol 18 No 5)
 

This is an interesting technique that can be added to the armamentarium of strategies in managing a corneal perforation between 1mm and 1.5mm where it is too large for medical management and small enough to be dealt with using this novel method. Larger defects would have to be dealt with either lamellar or full-thickness patch grafts. The authors describe a row of interrupted 10 / 0 nylon placed across the base of a perforation (90% depth) and then a ‘roll’ of amniotic membrane either epithelial or stromal side up placed across the base sufficient in length and width to cover the defect. The sutures are then tied over the roll. Over this a larger sheet of amniotic membrane is placed epithelial side up and anchored with 8/0 vicryl to the conjunctiva / episclera to protect the underlying tissue. (See Video http://links.lww.com/ICO/A22). Multilayered amniotic membrane for this purpose has been previously described, however, the beauty of this procedure lies in the ease of handling this tissue, which can be challenging if multiple very small pieces are fashioned to be then stacked into a small defect. The authors recommend the swiss roll technique in cases of severe thinning and localised perforations. Amniotic membrane consists of a single layer of epithelium, basement membrane, and an avascular stroma. It promotes epithelial differentiation band migration across its basement membrane and provides a scaffold for stromal repair. It also has anti-inflammatory and anti-fibrotic properties. It also secretes growth factors and is suitable for ocular surface surgery as it is devoid of human leucocyte antigen (HLA) meaning it is non-immunogenic.

Reference

“Swiss roll” amniotic membrane technique for the management of corneal perforations.
Chan E, Shah AN, O’Brart DPS.
CORNEA
2011;30:838-41.

Current Eye Research

Aquaporin-9 expression in eyes with glaucoma
Reviewed by: Badrul Hussain
Feb/Mar 2012 (Vol 18 No 5)
 

Aquaporin (AQP) water channels are of importance in maintaining ionic and osmotic balance in neuronal activity. AQP-9 belongs to an aquaglyceroporin subfamily and is permeable to lactate and glycerol, as well as water. Recent studies have shown that only AQP-9 is expressed in the optic nerve head (ONH) and elevated intraocular pressure (IOP) reduced its expression in rats. This preliminary Japanese study examined whether this holds true in the optic nerve of primate and human eyes. The expression of AQP-4 and AQP-9 was immunohistochemically studied in the optic nerves of a male cynomolgus monkey (an angle-laser-induced ocular hypertensive eye and a control fellow eye) and of human donor eyes (one control eye and one glaucomatous eye). This very small study has shown that, as in rats, the ONH in monkeys and humans expresses AQP-9, but not AQP-4. Elevated IOP or glaucoma reduces AQP-9 expression in the optic nerve. The reduction in astrocytic expression of AQP-9 in the optic nerve could be implicated in the development of glaucomatous optic neuropathy.

Reference

A preliminary study of reduced expression of aquaporin-9 in the optic nerve of primate and human eyes with glaucoma.
Mizokami J, Kanamori A, Negi A, Nakamura M.
CURRENT EYE RESEARCH
2011;36(11):1064-7.

Current Eye Research

In vitro toxicology of travoprost PQ
Reviewed by: Badrul Hussain
Feb/Mar 2012 (Vol 18 No 5)
 

Medically treated glaucoma patients require daily treatment with drops that typically contain preservatives. The most common ophthalmic preservative is benzalkonium chloride (BAK) which is directly toxic to ocular tissues. This study sponsored by Alcon Research compared the toxicological profile of travoprost PQ (travaprost 0.004% preserved with polyquaternium-1), with the standard formulation of travoprost BAK (travaprost 0.004% preserved with BAK), and BAK-preserved latanoprost 0.005%. Wong-Kilbourne-derived human conjunctival epithelial cells were cultured under standard conditions with phosphate-buffered saline (PBS), BAK 0.015%, BAK 0.020%, PQ 0.001%, travoprost PQ preserved with PQ 0.001%, travoprost with 0.015% BAK or latanoprost with 0.020% BAK. Six toxicological assays were used to assess cell viability, apoptosis and oxidative stress. There were no significant differences in toxicity between cells exposed to travoprost PQ or PQ 0.001%. Travoprost PQ produced significantly less cytotoxicity than latanoprost BAK (p<0.0001) and significantly better cell viability and less apoptosis than travoprost BAK (p<0.0001). All of the analyses showed that BAK 0.015%, BAK 0.020% and latanoprost BAK produced significantly more cytotoxicity than PBS (p<0.0001). The authors themselves state that in vitro studies do not replicate what happens in vivo and that clinical studies would be required to validate these comparisons in patients with glaucoma.

Reference

Comparative in vitro toxicology study of travoprost polyquad-preserved, travoprost BAK-preserved, and latanoprost BAK-preserved ophthalmic solutions on human conjunctival epithelial cells.
Brignole-Baudouin F, Riancho L, Liang H, Baudouin C.
CURRENT EYE RESEARCH
2011;36(11):979-88.

Current Eye Research

Tear osmolarity in patients with conjunctivochalasis
Reviewed by: Badrul Hussain
Feb/Mar 2012 (Vol 18 No 5)
 

Conjunctivochalasis (CCh) is described as redundant, loose, non-oedematous inferior bulbar conjunctiva between the globe and the lower eyelid. It is usually bilateral and the two most reported underlying aetiological theories are breakdown of elastic fibres in the redundant conjunctiva and conjunctival inflammation. In this Hungarian study, forty subjects were divided into four groups based on their lid-parallel conjunctival fold (LIPCOF). Each group contained ten patients. Tear samples were obtained from the right eye of patients for tear osmolarity measurement using an osmometer, the TearLab system. After this, classical dry eye tests (Schirmer test, tear film break up time (BUT) and vital staining) were performed. There was no difference in the age and gender between the four groups and a positive association was found between LIPCOF and age. Patients with mild and moderate CCh showed similar tear osmolarity to normal subjects, but a significant increase in tear osmolarity was found in patients with severe CCh (P<0.008), abnormal BUT (P=0.018) and in patients with positive lissamine-green staining (P=0.023). No association was found when tear osmolarity was compared with Schirmer test or with fluorescein staining. In the discussion, the authors state that increased tear osmolarity was referred as a fact of ocular inflammation and refer to previous studies showing that hyperosmolarity is a reason of ocular surface cell damage which can lead to inflammation. In this study, six cases of severe CCh had dry proved according to the TearLab guide. The authors hypothesise that on its own, mild or moderate CCh cannot lead to inflammation and that there is a connection between dry eye disease and CCh. However, in severe cases of CCh, primary hyperosmolarity could be due to dysfunction of the tear meniscus in the folds of conjunctiva and disruption of tear flow leading to delayed tear clearance.

Reference

Increased tear osmolarity in patients with severe cases of conjunctivochalasis.
Fodor E, Kosina-Hagyó K, Bausz M, Németh J.
CURRENT EYE RESEARCH
2012;37(1):80-4.

Experimental Eye Research

Hydrogel delivery of neurotrophic factors inducer
Reviewed by: Graham Wallace
Feb/Mar 2012 (Vol 18 No 5)
 

Optic nerve injury leads to the loss of retinal ganglion cells (RGC), possibly due to a decrease in production of neurotrophic factors. The dipeptide leucine-isoleucine (Leu-Ile) induces the production of neurotrophic factors which promotes survival of retinal ganglion cells. However, delivery of treatment to the retina is problematic and can have unwanted side-effects. To address this issue, Leu-Ile was delivered as a periocular injection, into the temporal subconjunctival space, in a poloxemer-alginate hydrogel in rats. Control injections were either hydrogel alone or Leu-Ile in saline. Initial results with FITC-labelled Leu-Ile showed that fluorescent intensity in the retina two hours after delivery was four-fold higher than saline controls. Delivery of Leu-Ile in hydrogel increased production of brain-derived growth factor and glial cell line derived growth factor, and RGC survival after optic nerve crush injury. These results demonstrate that Leu-Ile is released from the hydrogel and rapidly penetrates the retinal tissue, although this method did not offer a sustained delivery and may only provide transient RGC survival. However, the method proved safe and other hydrogel compositions may provide longer term release.

Reference

Periocular injection of in situ hydrogels containing Leu-Ile, an inducer of neurotrophic factors, promotes retinal ganglion cell survival after optic nerve injury.
Nakatani M, Shinohara Y, Takii M, et al.
EXPERIMENTAL EYE RESEARCH
2011;93(6):873-9.

Experimental Eye Research

Statins mediate RPE cell function
Reviewed by: Graham Wallace
Feb/Mar 2012 (Vol 18 No 5)
 

Proliferative vitreoretinopathy (PVR) is characterised by the growth of fibrous membranes into the neuroretina, leading to detachment. Retinal pigment epithelial cells are major players in PVR development as following injury they become activated and migrate into the vitreous cavity. Statins, in addition to the effects on cholesterol, interfere in vascular events including suppressing smooth muscle cell and macrophage proliferation. Morevoer, lovastatin has been reported to induce retinal pigment epithelium (RPE) cell apoptosis. In this paper the effects of atorvastatin (AVN) on a RPE cell line characteristics was examined. AVN induced growth arrest at both G1 and G2/M phases, adhesion to fibronectin and migration in 3D collagen gels. The effects of AVN were mediated by an increase in the Erk / MAPK pathways and a decrease in the JNK pathway. These results suggest that AVN has a potent effect on RPE cell characteristics that may be involved in PVR. While these studies were carried out in vitro and with a cell line, the results support the investigation of statins as therapeutic agents in PVR.

Reference

Pleiotropic role of atorvastatin in regulation of human retinal pigment epithelial cell behaviours in vitro.
Wu WC, Lai YH, Hsieh MC, et al.
EXPERIMENTAL EYE RESEARCH
2011;93(6):842-51.

Experimental Eye Research

TGFβ or PDGFβ blockade improves corneal opacity
Reviewed by: Graham Wallace
Feb/Mar 2012 (Vol 18 No 5)
 

Myofibroblast generation leads to haze and reduced opacity in corneal wound healing. The source of corneal myofibroblasts is still not clear, although transforming growth factor-β (TGFβ) has been shown to induce myofibroblasts from corneal fibroblasts in vitro. Studies have further suggested that TGFβ acts via an autocrine loop with platelet-derived growth factor-β (PDGFβ). In this paper corneal haze was induced in mice by phototherapeutic keratectomy, and the effect of vectors carrying inhibitors of either TGFβ or PDGFβ alone or together, or appropriate controls. After one month the corneas were examined by immunohistochemistry. The results show that corneas treated with vectors inhibiting TGFβ or TGFβ / PDGFβ had lower density of vimentin+ve cells (indicative of opaque corneal injury), and TGFβ or PDGFβ vectorsβ decreased α smooth muscle actin+ve myofibroblasts compared to eyes treated with control vectors. These results support a role for TGFβ and PDGFβ in myofibroblast induction in corneal injury, although only TGFβ affected vimentin expressing cells. Blocking these molecules may, therefore, be a useful pathway to investigate to maintain corneal function following injury

Reference

Effects of TGFβ and PDGFβ blockade on corneal myofibroblast development in mice.
Singh V, Santhiago MR, Barbosa FL, et al.
EXPERIMENTAL EYE RESEARCH
2011;93(6):810-7.

Eye

Life expectancy in glaucoma
Reviewed by: John Brookes
Feb/Mar (Vol 18 No 5)
 

This interesting paper looks at the possibility of calculating the combinations of age and disease stage at which patients are unlikely to become visually impaired during their lifetime. Data was obtained from residual life expectancy data and rates of progression derived from published studies. Calculations were made to derive the baseline mean deviation (MD) from which an individual would reach a MD of -20dB at the end of life as a function of age and rate of progression. A graphical tool was then developed which enables an estimate of the probability of becoming visually impaired during lifetime, given the individual’s age, current glaucomatous damage and the individual rate of progression, if known. This would allow clinicians to incorporate life expectancy in glaucoma care and provide personalised decision-making. The obvious limitations of this tool are estimating the rate of progression, which may take at least five years and also the life expectancy of an individual patient, which has to be estimated. For the situation in which the individual rate of progression is unknown, a computer simulation is used to calculate the percentage of patients who would become visually impaired before the end of life. The authors point out that this tool should not be used in all situations, especially secondary glaucomas, where there might be more rapid progression, ethnic groups known to progress more rapidly and field loss that might be threatening fixation. However, this would be of value if patients could be identified with minimal or no risk of visual impairment, to reduce excess treatment and monitoring and to reduce the costs and side-effects of treatment and also to identify patients with a high risk of vision impairment, to provide lower intraocular pressure (IOP) targets to minimise any further loss of vision.

Reference

Incorporating life expectancy in glaucoma care.
Wesselink C, Stoutenbeek R, Jansonius NM.
EYE
2011;25(12):1575-80.

Eye

Phenotypic variation in PAX6 mutations
Reviewed by: John Brookes
Feb/Mar 2012 (Vol 18 No 5)
 

The paired homeotic gene 6 (PAX6) gene is a key regulator in the development of the eye and central nervous system. It was identified as the causative gene in aniridia in 1991, following investigation of Wilm’s tumour. Aniridia is a rare panocular disorder, with a frequency of 1 in 64,000-96,000 live births. About two-thirds of cases are autosomal dominant, the remaining cases being sporadic. The PAX6 gene is located on chromosome 11p13 and is expressed early in the development of the eye. It is the only gene identified to be responsible for aniridia. There have been more than 300 intragenic mutations of the PAX6 gene described to date. Missense mutations usually cause non-aniridic phenotypes, including anterior segment anomalies, such as Peter’s anomaly. This study looked at mutation screening of the PAX6 gene in a cohort of affected individuals with different clinical phenotypes. On the basis of clinical phenotyping, patients were grouped into those with aniridia, those with coloboma of the iris and choroid and those with anterior chamber malformations, including Peter’s anomaly. Peripheral blood was extracted for mutation screening. The authors report data on six families and 10 sporadic cases with different clinical phenotypes. The patients with aniridia presented with a similar phenotype, with complete absence of the iris, congenital nystagmus and cataract. Three intragenic mutations were detected in this group, which could result in premature termination of PAX6 translation. The authors suggest that the results are consistent with the hypothesis that haploinsufficiency of the gene causes the classical aniridia phenotype. In the second group, iris and choroid coloboma, neither intragenic mutations of PAX6 or large delations were detected and the patients in the third group, Peter’s anomaly, showed a missense mutation in the PAX6 gene, which is thought to interfere with the correct folding of the protein. This study has identified four intragenic mutations and one large deletion in a set of patients with different clinical phenotypes. They suggest that mutations that introduce premature termination codons or whole PAX6 gene deletion cause a classical aniridia phenotype, whereas missense mutations result in Peter’s anomaly. PAX6 mutations are not responsible for coloboma of the iris or choroid. It is thought that clinical phenotype classification may increase the mutation detection rate of the PAX6 gene.

Reference

Two novel mutations of the PAX6 gene causing different phenotype in a cohort of Chinese patients.
Zhang X, Tong Y, Xu W, et al.
EYE
2011;25(12):1581-9.

Journal of Pediatric Ophthalmology and Strabismus

Capillary hemangioma management
Reviewed by: Fiona Rowe
Feb/Mar 2012 (Vol 18 No 5)
 

The purpose of this paper is to provide an overview of the theories of pathogenesis of capillary hemiangioma and to discuss current treatment options. The authors discuss roles for vasculogenesis and angiogenesis plus diagnosis with clinical, imaging and tissue evaluation. The authors consider disease management including timing of treatment, advantages and disadvantages of steroids, timing of laser treatment, indications for surgical excision, immunotherapy and chemotherapy and use of Beta-adrenergic antagonists.

Reference

New developments in the management of periocular capillary hemangioma in children.
Ni N, Wagner RS, Lauger P, Gua S.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(5):269-76.

Journal of Pediatric Ophthalmology and Strabismus

Conjunctival cysts
Reviewed by: Fiona Rowe
Feb/Mar 2012 (Vol 18 No 5)
 

The aim of this study was to analyse the different factors that may be related to the appearance of conjunctival cysts after strabismus surgery in an observation, longitudinal and retrospective study of 12 cases. Treatment was with complete surgical removal as recurrence is seen after simple puncture and cauterisation. Total exeresis of the capsule is essential. The incidence of cysts was 0.25%.

Reference

Conjunctival cysts as a complication after strabismus surgery.
Guadilla AM, Gomez de Liano P, Merino P, Franco G.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(5):298-300.

Journal of Pediatric Ophthalmology and Strabismus

Exo angle after correction of hypermetropia
Reviewed by: Fiona Rowe
Feb/Mar 2012 (Vol 18 No 5)
 

This study aimed to determine whether hypermetropic correction affects the angle of deviation and surgical outcomes in patients with intermittent exotropia and to compare these results with patients with myopia or emmetropia. The results indicate that some exotropic patients with moderate hypermetropia demonstrate an increase in deviation after spectacle correction. The increased angle with spectacles was more pronounced in patients with exotropia who had pure hypermetropia than in those who had hypermetropic astigmatism or amblyopia. The authors recommend a spectacles trial for exotropia patients with pure hypermetropia of moderate degree to accurately establish the angle of deviation before considering surgery.

Reference

Changes in exodeviation following hyperopic correction in patients with intermittent exotropia.
Chung SA, Kim IS, Kim WK, Lee JB.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(5):278-84.

Journal of Pediatric Ophthalmology and Strabismus

Hyaluronic acid film use
Reviewed by: Fiona Rowe
Feb/Mar 2012 (Vol 18 No 5)
 

The authors evaluated and examined the effect of hyaluronic acid film on postoperative scar formation in rabbit ocular tissues to clarify the potential benefit in strabismus surgery. The film changes from a solid form into a gel form within 24-48 hours in the tissue and stays within the tissue for approximately seven to fourteen days. This material functions as a barrier to contact between separated tissues, thus reducing a delaying postoperative formation of adhesions. The materials are eventually absorbed. The authors propose that the application of this film to ocular surface operations will provide a safe and effective procedure for preventing postoperative adhesions around surgical wounds in conjunctiva, sub-conjunctiva, sclera or extraocular muscles.

Reference

Effects of solid hyaluronic acid film on postoperative fibrous scar formation after strabismus surgery in animals.
Takenchi K, Nakazawa M, Metoki T, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(5):301-4.

Journal of Pediatric Ophthalmology and Strabismus

IOL sclera fixation
Reviewed by: Fiona Rowe
Feb/Mar 2012 (Vol 18 No 5)
 

The authors report the results and complications of sclera fixation of intraocular lens (IOL) in traumatised eyes without adequate capsule and iris tissue in paediatric patients. This was a retrospective study of ten patients (ten eyes) with open globe injury. All had primary repair of the laceration, pars plana vitrectomy and lensectomy. Uncorrected visual acuity did not improve postoperatively in only one eye. Scleral fixation of the intraocular lens is recommended where more convenient methods of aphakia correction such as contact lens, iris fixation and anterior chamber intraocular lens, are not suitable.

Reference

Scleral fixation of intraocular lens in eyes with history of open globe injury.
Banaee T, Sagheb S.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2011;48(5):292-7.

Journal of Refractive Surgery

Phakic intraocular lenses for myopia
Reviewed by: Amit Patel
Feb/Mar 2012 (Vol 18 No 5)
 

This is a retrospective study evaluating the outcomes of 204 consecutive eyes (of 104 US military warfighters) implanted with a phakic intraocular lens (VIsian ICL). Three-month follow-up outcomes are reported on 135 eyes. Indications included non-suitability for LASIK (abnormal corneal topography, thin central corneal thickness and predicted residual bed, dry eye symptoms), predicted postoperative keratometry <35.0 Dioptres (D) and history of cheloid / corneal scarring. All patients underwent a peripheral iridotomy. No intraoperative complications were recorded. Four eyes had elevated intraocular pressure two hours postoperatively and three eyes required lens exchange (two eyes for lens calculation error and one for excessive lens vaulting). Four eyes experienced halos which settled with miosis (induced with brimonidine). Three eyes experienced glare secondary to the iridotomy. One eye experienced postoperative iritis which settled with topical steroids. Three-month postoperative uncorrected distance visual acuity (UDVA) was ≥20/20 in 129 eyes (96%) and ≥20/15 in 91 eyes (67%). Ninety percent (115/128 eyes) were within ±0.50 D of emmetropia and 127/128 eyes (99%) within ±0.75 D of the predicted outcome.
The early outcomes compare favourably with those of laser vision correction reported in a similar group of patients; however, the authors acknowledge that the follow-up is not long enough to determine the appropriateness in military use. This study also deviates from the manufacturers recommendation on several issues: a) endothelial cell counts were not checked postoperatively, b) the preoperative refractive stability was greater than ±0.5 D and c) 13 eyes had an anterior chamber depth <3.0mm.

Reference

Phakic intraocular lens implantation in United States military warfighters: a retrospective analysis of early clinical outcomes of the Visian ICL.
Parkhurst GD, Psolka M, Kezirian GM.
JOURNAL OF REFRACTIVE SURGERY
2011;27(7):473-81.

Journal of Refractive Surgery

Phakic IOL implantation after collagen crosslinking
Reviewed by: Amit Patel
Feb/Mar 2012 (Vol 18 No 5)
 

Eleven eyes with progressive keratoconus were treated with collagen crosslinking (CXL) followed by implantation of a foldable Artisan (Artiflex) phakic intraocular lens six months later. Preoperative spherical equivalent ranged from -4.00 to -7.50 Dioptres (D). Mean reduction in spherical equivalent six months following CXL was 0.45 D (p=0.3) and 5.43 D following Artiflex implantation. There was a greater reduction in keratometry following the Artiflex implantation (2.14 D, p<0.001) compared to post-CXL treatment (1.27 D, p=0.2). Mean endothelial cell loss was 3.29% (p=0.3) six months after Artiflex implantation. All patients experienced a gain in uncorrected distan