Duration of diabetes and prevalence of diabetic retinopathy: Istanbul Diabetic Retinopathy Study—IDRS results 1

Abstract

Summary Aim To find out the prevalence of diabetic retinopathy (DR) in patients with type 1 (T1DM) and type 2 diabetes mellitus (T2DM). Materials and methods The study group consists of diabetic patients applying to the Diabetes Outpatient Clinic of Istanbul Medical Faculty and who had ophthalmological examination between the years 2003 and 2004. Three hundred and seventy patients with T1DM (mean chr. age 26.9 ± 11.3 years, mean duration of DM 8.5 ± 7.0 years) and 1332 patients with T2DM (mean chr. age 58.5 ± 10.9 years, mean duration of DM 10.2 ± 7.4 years) were included. Results Diabetic retinopathy was diagnosed in 42.8% of patients (33.2% in T1DM, 45.5% in T2DM). The prevalence of nonproliferative DR was 4.7% in patients with duration of T1DM ≤5 years and 45.8% with duration of T1DM >20 years. These prevalences were 18.7 and 60.6% in patients with T2DM, respectively. As to the prevalence of proliferative DR in patients with duration of DM ≤ 5 years, 0.7% in T1DM, and 0.4% in T2DM; in patients with duration of DM > 20 years it was 20.8 and 9.1%, respectively. Both in T1DM and T2DM the presence and the severity of DR was increasing as the duration of DM increases (p = 0.00). Conclusion High prevalence of diabetic retinopathy in T1DM and T2DM patients with duration of diabetes 5 years or less is noticeable. Starting the screening early preferably at the time of diagnosis, regular follow-up together with good metabolic control will serve to prevent the sight-threatening diabetic retinopathy.