The Effect of Long-term Near Normal Glycemic Control on Mild Diabetic Retinopathy

Thirty-three type I diabetics who used continuous subcutaneous infusion of insulin (CSII) and 24 diabetics on conventional treatment (maximum of two injections per day) were studied prospectively with ophthalmologic examinations, fundus photography, fluorescein angiography, and glycosylated hemoglobin (HbA1) determinations. Both groups were similar with respect to age, duration of diabetes, and length of follow-up. At entry almost all patients had only mild forms of diabetic retinopathy although three CSII patients had early proliferative retinopathy. The CSII groups achieved superior glycemic control throughout the study (mean HbA1 = 7.4% vs. 10.2%). After an average follow-up of more than 30 months, the CSII group showed significantly less progression of diabetic retinopathy as measured by macular aneurysm counts and by modified ETDRS grading. Careful control of glycemia may delay the progression of diabetic retinopathy.