Proliferative retinopathy in NIDDM. Incidence and risk factors in Pima Indians

The incidence of proliferative diabetic retinopathy was determined in the Pima Indians of the Gila River Indian Community in Arizona. Over 4 yr, this complication developed in 25 of 953 subjects greater than or equal to 9 yr of age with non-insulin-dependent diabetes. No cases were diagnosed in less than 35-yr-old subjects, and the incidence was strongly related to the duration of diabetes. The cumulative incidence of proliferative retinopathy after 20 yr duration was 14%. All cases of proliferative retinopathy occurred in subjects with background retinopathy. Younger age at diagnosis of diabetes was associated with a higher incidence of proliferation when subjects with diabetes of similar duration were compared. A higher incidence of proliferative retinopathy, after controlling for age, sex, and diabetes duration, was associated with hypertension, proteinuria, renal insufficiency, absence of Achilles tendon reflex, elevated total serum cholesterol concentration, and insulin therapy.