PAEDIATRIC CATARACT

Cataract is a condition where the natural transparent lens of the eye becomes cloudy or opaque which affects the clarity of vision. It is a widely prevalent myth that cataract only occurs in old age. The reality is that it could even affect a new-born baby and the condition is then called as paediatric cataract.

Cataract is one of the leading causes of blindness in children. The prevalence of cataract in India is about 15 in per 10,000 children. Earlier detection of cataract in children helps in achieving a better visual outcome. If left untended, it could lead to complete or partial loss of vision. Genetic factors, infections during pregnancy, side effects of medication and injuries are few of the most culpable reasons causing cataract in children.

Types and Severity of Paediatric Cataract

Paediatric cataracts can occur in one eye (unilateral) or both eyes (bilateral). They can be complete or partial and can be present at birth or occur sometime after birth. Cataracts can be partial at birth and later progress to become visually significant.

Unilateral infantile cataracts are rarely caused by a systemic disease, except in some cases of intrauterine infections such as rubella. Generally, monocular congenital cataracts have a relatively good prognosis if surgery and optical correction is provided by two months of age. Beyond this age, there is a possibility of having dense amblyopia in the operated eye.

Bilateral cataracts are often inherited. The work-up for bilateral congenital or infantile cataracts should include a careful paediatric examination and special tests. Dense bilateral congenital cataracts require urgent surgery and visual rehabilitation. In general, bilateral cataracts operated prior to two months of age have a good visual prognosis with approximately 80% achieving vision of 20/50 or better.

Accompanying conditions with Paediatric Cataract

In contrast to adults, cataracts in children present a special challenge, since early visual rehabilitation is critical to prevent irreversible amblyopia (lazy eyes). The earlier the onset, and the longer the duration of the cataract, the worse the prognosis. With new techniques and material in the treatment of congenital cataracts and improved surgical and clinical management, visual prognosis has improved. Now ophthalmologists operate as early as the first week of life and visually rehabilitate the child with either glasses or contact lenses.

Children born with cataracts are also at risk for developing glaucoma, strabismus, nystagmus, and poor stereopsis, further complicating successful outcomes. In most cases, it is the willpower and resolve of the parents or caregivers to follow post-operative management that determines visual success for the child. Patients with acquired progressive cataracts have less amblyopia and a much better visual prognosis than patients with cataracts that cover the visual axis since birth.

Identification of Cataract in Children

Children who are born with cataract will have a white reflex at the centre of the black portion of the eye; this symptom is the most common one which could be identified just by shining a torchlight on the child’s eyes. Children with cataract may exhibit some degree of sensitivity; they observe things by holding them close to their face, fail to identify common faces from a certain distance. Sometimes a child with the cataract in one eye may not show any symptom at all, as he/she can perceive things through the other eye.

When visiting the Paediatric Ophthalmologist, he may advise a few tests to check vision, ascertain the type of cataract and the extent to which it has affected the child’s eye.

Treatment of Paediatric Cataract

Some cataracts may not affect the vision considerably, in such cases, glasses can serve the purpose. If the cataract affects the vision significantly a surgical treatment is suggested. The surgical treatment involves removal of the cataract and replacing it with an artificial intraocular lens.

Cataract surgery in children is done under general anaesthesia. It involves removal of the cataractous (opaque) crystalline lens. This is often accompanied by surgical measures (primary posterior capsulorrhexis /anterior vitrectomy) to ensure the clarity of the central visual axis in the postoperative period, which can otherwise get obscured by the ‘after cataract’ (collection of inflammatory cells and fibrous tissue) formation.

We currently consider IOL implantation in patients who are one year or older, and IOL implantation is the procedure of choice in children 2 years and older. The use of aphakic glasses or contact lenses continues to be the treatment of choice for congenital cataracts in neonates, while an IOL is preferred for children over one year of age.

Some children who are born with relatively smaller eyes, implanting an artificial lens may be a challenge. In such children, contact lenses or glasses are advised until they become 3-4 years of age after which intraocular lens could be implanted.

Postoperatively, the treatment does not just stop at surgery, there may be a need for the child to use glasses for near reading and writing. Regular follow-ups are also advisable. The child may require occlusion therapy for the management of amblyopia.