Prevalence and risk factors for retinopathy in persons without diabetes: the Singapore Indian Eye Study

Abstract

PURPOSE: To describe prevalence and risk factors for retinopathy in an Asian Indian population without diabetes. METHODS: A population-based cross-sectional study of 3400 Indians aged 40-80 years residing in Singapore was conducted. Retinopathy was assessed from retinal photographs by trained graders using modified Airlie House Classification System. Risk factors were assessed from standardized interviews, clinical examinations and laboratory investigations. Diabetes mellitus was defined as glycosylated haemoglobin ≥6.5%, use of diabetic medication or physician diagnosis of diabetes. RESULTS: Among the 1900 individuals without diabetes, mean HbA1c was 5.7% and mean systolic blood pressure was 132.4 mmHg. Age-standardized prevalence of retinopathy was 5.05% (n = 98; 95% confidence interval [CI], 4.07-6.21), with no significant difference in retinopathy prevalence between males (6.15%) and females (4.13%). Among non-diabetic persons with retinopathy, 96.9% (n = 95) had signs of minimal-to-mild retinopathy while 3.06% (n = 3) had moderate-to-severe retinopathy. After adjusting for multiple covariables, retinopathy signs were associated with higher levels of HbA1c (odds ratio [OR], 2.4; 95% CI, 1.3-4.5; per% increase), systolic blood pressure (OR, 1.02; 95% CI, 1.01-1.03; per mmHg increase) and serum creatinine (OR, 1.005; 95% CI, 1.002-1.009; per mm increase), but not C-reactive protein, cigarette smoking or lipid levels. CONCLUSION: One in 20 Asian Indian persons without diabetes had retinopathy signs. Risk factors for these signs include higher glycosylated haemoglobin, systolic blood pressure and serum creatinine.