Retinopathy in diabetes.

D iabetic retinopathy is the most frequent cause of new cases of blindness among adults aged 20 –74 years. During the first two decades of disease, nearly all patients with type 1 diabetes and 60% of patients with type 2 diabetes have retinopathy. In the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR), 3.6% of younger-onset patients (type 1 diabetes) and 1.6% of olderonset patients (type 2 diabetes) were legally blind. In the younger-onset group, 86% of blindness was attributable to diabetic retinopathy. In the older-onset group, in which other eye diseases were common, one-third of the cases of legal blindness were due to diabetic retinopathy.