Pediatric cataract: the Toronto experience-etiology.

PURPOSE: To study the etiology and characteristics of pediatric cataracts in a large sample from 1 institution. DESIGN: Observational case series. METHODS: The study population included 778 consecutive cases (1122 eyes) of children presenting with any type of pediatric cataract over a 10-year period. Age at presentation, laterality, cataract morphology and etiology, and presence of strabismus were recorded. Association with systemic diseases or syndromes and coexistent ocular anomalies were noted. Snellen or Allen picture charts were used to record visual acuity, when able. RESULTS: Unilateral cataract accounted for slightly over half of the cases. The etiology was idiopathic in the majority of patients. The most common systemic association was diseases with steroid treatment-induced cataracts. Cataracts, when associated with other isolated ocular anomalies, tended to occur unilaterally. Among syndrome-associated cataracts, Down syndrome represented a third of the cases. Posterior subcapsular cataract was the most common morphologic type. Almost half of the patients presented with Snellen 6/9 or better or "central, steady, maintained" vision where it was not possible to obtain quantitative vision data. CONCLUSIONS: Despite the diverse nature of cases with frequent systemic associations, unilateral cataracts and idiopathic etiology accounted for the majority of cases.