Diabetic retinopathy in Joslin Clinic patients with adult-onset diabetes.

While only a small proportion of adult-onset diabetic patients develop vision threatening retinopathy, this group makes up a major portion of those diabetics seeking ophthalmologic care. Fifty-three percent of patients having fundus photographs at the W.P. Beetham Eye Unit of the Joslin Clinic developed diabetes at the age of 20 or over, and almost 30% at the age of 40 or over. Twenty-two percent of all patients seen with proliferative retinopathy were in this latter group. Ten of 54 patients with proliferative retinopathy in the greater than or equal to 40 onset group were not taking insulin. The older onset patients who developed proliferative retinopathy did so after shorter durations of diabetes and with more visual disability than younger onset patients. Macular edema was more common in adult-onset patients, and its presence in a patient less than 50 years old was usually associated with proliferative or preproliferative retinopathy.