ACQUIRED OCULAR VISUAL IMPAIRMENT IN CHILDREN - 1960-1989

Objective.-To describe the causes, sites, and types of eye anamoly and associated handicaps in children identified in the last 30 years with ocular visual impairment of 20/200 (6/60) or worse in the better eye with correction. Design.-Trend study. Study Population.-Children in British Columbia younger than 19 years with visual loss diagnosed between January 1960 and December 1989 who were referred for multidisciplinary assessment. Results.-The incidence of acquired ocular visual impairment has decreased from 0.6 to less than 0.2 per 10 000 people aged 19 years or younger during the last 30 years. The most common cause was a genetic cause, followed by tumor, injury, infection and autoimmune disorders. Optic nerve atrophy and retinal disorders together resulted in more than 90% of all ocular lesions. Gender distribution revealed more males than females to be affected. Sixty-six percent of children had enough sight to read. The percentage of affected children with neurologic disabilities has increased overall in the last 30 years because more children with profound brain damage have survived. Conclusions.-Acquired ocular visual impairment is rare. The incidence of such impairment has been reduced by two thirds in the last 30 years. This decline has had little impact, however, because most cases of blindness are due to congenital conditions. The number of cases of acquired blindness is only one fourth that of congenital blindness, which has begun to increase again owing to the reemergence of retinopathy of prematurity.