The Wisconsin Epidemiologic Study of Diabetic Retinopathy. A comparison of retinopathy in younger and older onset diabetic persons.

In a population-based survey of diabetic persons, retinopathy was detected by stereoscopic color fundus photography in 70% of persons under 30 years of age at diagnosis and taking insulin (Group YO), in 62% of persons 30 years of age or older at diagnosis and taking insulin (Group OO-I) and in 36% of persons 30 years of age or older at diagnosis not taking insulin (Group OO-N). The mean duration of known diabetes was 14.6 years in Group YO, 11.0 years in Group OO-I and 6.9 years in Group OO-N. After 20 years of diabetes, proliferative retinopathy was present in about 50% of Group YO, about 25% of Group OO-I and about 5% of Group OO-N. After 15 years of diabetes, macular edema was present in about 18% of Group YO, about 20% of Group OO-I and about 12% of Group OO-N. When present, macular edema tended to be associated with more hard exudate in Group OO-N.