Diabetic retinopathy has been and probably remains one of the four major causes of blindness in the United States.¹,² The risk of retinopathy is directly related to the degree and duration of hyperglycemia.³ After diabetes mellitus has been present for 20 years, almost all persons in whom the onset of diabetes occurred before the age of 30 years have some evidence of retinopathy, and about half have proliferative retinopathy. Persons who are 30 years of age or older when diabetes develops are at lower risk for retinopathy, but in this group retinopathy may be the first sign of diabetes. . . .