The Prevalence of Diabetic Retinopathy in Tehran Province

To determine the prevalence and characteristics of retinopathy in diabetic residents of Tehran Province, Iran, during 2005, we conducted this cross-sectional study on 700 patients with diabetes who were diagnosed in a sample of 7500 individuals in the “Risk Factor Evaluation for Non-Contagious Diseases” project performed in 2005 in Iran. All patients were invited to attend a certain location for the study. All participants underwent systemic examination by an internist and a comprehensive ophthalmic examination including funduscopy with pupils fully dilated by a vitreoretinal specialist. Totally, 634 diabetic subjects with a mean±SD age of 59.3±12.0 (range: 18 – 78) years were enrolled. Retinopathy was detected in 37.9% (95%CI: 34.1 – 41.6%) of patients. It included 72.9% (95%CI: 67.3 – 78.5%) nonproliferative and 27.1% (95%CI: 21.5 – 32.7%) proliferative diabetic retinopathy. The prevalence of bilateral blindness was 2.1% and 0.8% in diabetic patients with and without retinopathy, respectively (P<0.001). Logistic regression analysis revealed that diabetic retinopathy is associated with male gender (P=0.022), increased disease duration (P<0.001), diabetes control regimen (P<0.001), and presence of diabetic nephropathy (P=0.003).