Prevalence of Diabetic Retinopathy and Associated Factors in Type 2 Diabetes Mellitus in Maharat Nakhon Ratchasima Hospital

Objective: To determine the prevalence of diabetic retinopathy (DR) and its associated factors in type 2 diabetes in Department of Medicine, Maharat Nakhon Ratchasima Hospital. Patients and Methods: A cross-sectional, hospital-based study was carried out between April and December 2003. Diabetic patients, type2 in diabetic clinics in Maharat Nakhon Ratchasima Hospital were registered. Their associated factors such as fasting blood glucose, glycosylated hemoglobin (hemoglobin A1c; HbA1c), blood pressure (BP), serum creatinine, urinary examination, etc was collected. Retinal examination of the participants was performed by ophthalmologists. Results: 633 of 1066 (59.4%) diabetic patients received retinal examination using direct ophthalmoscopy after full dilatation of pupils. The prevalence of DR was 17% (n=108) which consisted of non-proliferative DR (NPDR) 7.6% (n=48), proliferative DR (PDR) 9.5% (n=60). Patients with DR significantly had longer duration of diabetes, higher HbA1c, higher systolic BP levels, higher incidence of nephropathy (proteinuria or renal insufficiency) than those without DR. The factors associated with DR expressed as adjusted Odds ratio (95% confidence interval) were 1) duration of diabetes 1.2 (0.6-2.28) for duration of 5-9.9 years, 2.1 (1.13-4.04) for duration of 10-14.9 years, 1.9 (0.81-4.27) for duration of 15-19.9 years, 4.6 (2.09-10.18) for duration of >20 years when compared with duration of diabetes of less than 5 years, 2) latest HbA1c >7% 2 (1.13-3.59) when compared with HbA1c 130 mmHg 1.8 (1.14-2.92) when compared with systolic BP <130 mmHg, 4) nephropathy status i.e. positive proteinuria 1.8 (1.05-2.96) and renal insufficiency 2.4 (1.23-4.87) when compared with no nephropathy. Conclusion: Diabetic retinopathy is one of the common complications of diabetes. The authors found the factors associated with DR were longer duration of diabetes, high latest HbA1c level, high systolic BP and present diabetic nephropathy.