Incidence of retinopathy and associated risk factors from time of diagnosis of insulin-dependent diabetes

Objective: To describe the prevalence at baseline and 4-year incidence of retinopathy and its relation to glycemic control from the time of diagnosis of insulin-dependent diabetes. Design: Geographically defined population-based study. Setting: Twenty-eight-county area in Wisconsin. Study Population: Incipient cohort of children, teenagers, and young adults (n=354) up to 30 years of age with newly diagnosed insulin-dependent diabetes. Main Outcome Measure: Diabetic retinopathy as determined by gradings from 30 degrees color stereoscopic photographs of the Diabetic Retinopathy Study 7 standard fields. Results: The prevalence of retinopathy at diagnosis was 1.3%. Four years after diagnosis of diabetes, retinopathy was first identified in 5.1% of our cohort and in 9.7% of those 15 years of age or older. After controlling for age, subjects with a mean glycosylated hemoglobin level of 12% or greater were 3.2 times as likely (95% confidence interval, 1.1-9.9) to have retinopathy present at follow-up as were subjects with a mean glycosylated hemoglobin level of less than 12%. Conclusion: Population-based data on the frequency and incidence of retinopathy from the time of diagnosis of insulin-dependent diabetes mellitus provided by this study suggest a possible reduction in risk of developing retinopathy in those in whom glycemic control is achieved from the time of diagnosis.