Congenital cataract is the clouding or opacification of the lens that occurs at birth or weeks after (infantile cataract). They can be unilateral or bilateral and vary in form, size and location, and consequently the visual impact, management course and visual prognosis is on a spectrum.
It is a relatively uncommon condition with a global prevalence of between 2.2/10,000 and 13.6/10,000 [1]. In the UK, all newborns have routine red reflex screening. However, despite these low numbers, significant vision loss is a considerable risk from amblyopia in some and hence this condition requires urgent expert assessment.
Aetiology
Congenital cataract can be hereditary, part of other ocular or systemic syndromes, or idiopathic. Unilateral cataract is mostly idiopathic compared to bilateral cases that usually stem from systemic syndromes (see Table 1).
Morphology
Congenital cataracts are classified according to their appearance and location in the lens. The main types of cataracts are anterior pole, fetal nuclear, cortical lamellar, posterior pole, posterior lenticonus and total. It also occurs in a special condition called persistent fetal vasculature (see Table 2).
Investigations
Unilateral cataracts or those with a family history may not always require extensive investigations. For bilateral cataracts with no family history, consider the following investigations in co-ordination with a paediatrician:
- Urinalysis (reducing substances and amino acids)
- Serology ‘TORCH’ screen
- Biochemical profile
- Erythrocyte enzyme analysis including G1PUT
- Karyotyping and clinical genetics referral.
(See Table 3).
Management
The management approach for paediatric cataract differs to that in adults as various other considerations need to be accounted for including the anatomically younger tissues, ocular growth and any other associated structural abnormalities. The main issue is the refractive uncertainty of implanting an intraocular lens (IOL) when there is still pending ocular growth as opposed to the risk of glaucoma when leaving a child aphakic. Moreover, paediatric cataracts require longterm follow-up for the management of associated amblyopia. It is important to note that not all cases require cataract surgery; those with small, partial cataracts not affecting the visual axis can be managed by observation. Pharmacological pupillary dilation can be a helpful adjunct in some cases or part time occlusion can be considered with cases considered to be at risk for amblyopia and may aid in delaying surgery to an age where surgery is safer or ocular growth has stabilised. However, they will need to be closely monitored as earlier surgical intervention may be required in patients unresponsive to the aforementioned techniques.
Surgery
The timely removal of visually significant congenital cataracts is imperative for a good outcome. As a guide unilateral cases are recommended to be operated at six weeks of age, compared to bilateral cases, where it is recommended around 10 weeks of age. The risk of amblyopia should be balanced with that of developing glaucoma from aphakia. It is vital that the parents are counselled adequately regarding the visual prognosis and postoperative care and level of compliance required from their part as the results of surgery and risk of complications depend hugely on this.
The surgical approach taken depends on the age of the patient, other associated conditions (ocular and systemic) and the extent of the cataract. Paediatric eyes have lower corneal and scleral rigidity, very elastic anterior capsules, soft lenses, and well-formed vitreous. Typically for children aged under one year a lensectomy with primary posterior capsulotomy and anterior vitrectomy is performed. The anterior and posterior capsular rim is left intact for a secondary IOL at a later date. These children will be left aphakic and subsequently require visual rehabilitation with glasses, contact lenses. In older children, a lensectomy (with or without primary posterior capsulotomy and anterior vitrectomy) and potentially a lens implant can be considered. These children may require careful refractions for bifocals (even with IOL implantation). In children aged above five years a posterior capsulotomy may not always be necessary at the time of the initial surgery if they are able to sit and be compliant at the slit lamp for a YAG laser, if needed later after cataract extraction. All incisions should be sutured close and a protective shield given to young children at risk of inadvertently rubbing the eye.
Postoperative period
Good postoperative care is vital and depends on a team approach between the parents, ophthalmologists, orthoptists and optometrists. Children typically have a more prolonged period of postoperative inflammation with a need for more frequent administration and longer duration of topical steroids (see Table 4).
Conclusion
Congenital cataract is an uncommon but important condition that should not be missed due to high risk of associated amblyopia development. Unilateral cases or bilateral cases with family history do not need investigation always and in cases that do, liaise with the paediatrician. Good postoperative care is essential in optimising results of surgery and hence parents should be carefully counselled and communicated with as well as have adequate management of amblyopia.
References
1. Wu X, Long E, Lin H, Liu Y. Prevalence and epidemiological characteristics of congenital cataract: a systematic review and meta-analysis. Scientific Rep 2016;6:28564.
2. Magnusson G, Bizjajeva S, Haargaard B, et al. Congenital cataract screening in maternity wards is effective: evaluation of the Paediatric Cataract Register of Sweden. Acta Paediatr 2013;102(3):263–7.
3. Whitman MC, Vanderveen DK. Complications of pediatric cataract surgery. Semin Ophthalmol 2014;29(5-6):414–20.
4. Birch EE, Cheng C, Stager DR Jr, et al. The critical period for surgical treatment of dense congenital bilateral cataracts. J AAPOS 2009;13(1):67–71.
5. Lenhart PD, Lambert SR. Current management of infantile cataracts. Surv Ophthalmol 2022;67(5):1476–505.
6. https://eyewiki.org/Cataracts_in_Children,_Congenital_and_Acquired
[Link last accessed February 2025]
7. Denniston AKO, Murray PI (Ed.). Oxford Handbook of Ophthalmology, Fourth Edition. London: Oxford University Press; 2018.
Declaration of competing interests: None declared.
