Congenital cataract

Lead investigator

Dr J Rahi

About the study

At the time of surveillance, despite considerable recent progress in the surgical and optical management of congenital and infantile cataract, a significant proportion of treated children continue to be registered blind (up to 30% in the United States of America). Congenital and infantile cataract could also cause mild or moderate visual impairment, which could go unrecognised, particularly if it is unilateral. In children with multiple disabilities, it may have been the most readily treatable eye disorder and the improved vision that results from treatment may have contributed to the child’s overall development.

Early detection and treatment of congenital and infantile cataract was probably the most important of several factors relevant to good visual outcome. In humans, the ‘critical period’ during which interventions to prevent the development of irreversible amblyopia were likely to be most successful is from birth to 10 weeks of age. The best reported visual outcomes were in children who had undergone surgery early within this period. Early surgical intervention required detection and ophthalmic referral in the neonatal period. Children not identified by specific neonatal examination would present at different ages and to various health professionals, depending on the severity of visual loss and the presence or absence of other ocular or systemic disorders. The patterns of presentation and detection in the United Kingdom, including the age at presentation, to whom the child first presented, and the reason for first presentation, were not known.

Epidemiological data on congenital and infantile cataract were important to the development of effective recommendations about its early detection and ophthalmic management. The main sources of data on congenital and infantile cataract in the United Kingdom were registers of partial sight and blindness, surveys of children attending schools for the blind and clinical case series. All these sources were limited in terms of completeness, potential bias or detail, and most studies based on them had been retrospective. Hospital data suggested ophthalmologists in the United Kingdom saw about 150 new cases each year, but the birth prevalence was not known.

Numerous causes of congenital and infantile cataract had been reported, but it was not known if the underlying cause was associated with the patterns of detection or of ophthalmic referral. Surgical and optical treatment techniques for congenital and infantile cataract have seen advancements in recent years, but there were no uniform treatment policies for either unilateral or bilateral cases. Different centres reported the results of their management regimens. Many reports involved small numbers of patients and provided limited data.

Research questions:

1. To estimate the birth prevalence of congenital and infantile cataract in the British Isles.
2. To determine the national and regional patterns of presentation and ophthalmic referral.
3. To assess aetiology in incident cases and to determine the proportion attributable to preventable causes.
4. To determine the factors associated with good visual outcome.

Duration

October 1995 – October 1996

Published papers

Fight for Sight
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