Diabetic Retinopathy in Diabetics Referred to a Tertiary Centre from a Nationwide Screening Programme

Abstract

Introduction: The aim of the study was to describe the prevalence and risk factors for diabetic retinopathy in a multi-ethnic diabetic patient cohort referred for retinal evaluation from a nationwide diabetic retinopathy screening programme in Singapore. Materials and Methods: Seven hundred and forty-two patients, aged 21 to 95, referred for suspected diabetic retinopathy on annual one-field non-mydriatic 45 degree retinal photographs (Topcon TRC-NW6, Topcon Corporation, Tokyo, Japan) from primary care to the Singapore National Eye Centre diabetic retinopathy clinic were included. The photographs had been interpreted by 24 trained family physicians accredited every 2 years with a training programme. Patients underwent a standardised interview and examination. Fundi were examined with indirect ophthalmoscopy by 2 examiners. Presence and severity of diabetic retinopathy was graded into none, mild, moderate, severe, very severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. Macular oedema and clinically significant macular oedema were also graded. Results: Ninety-nine per cent of patients were type 2 diabetics. The prevalence of diabetic retinopathy was 38.1%, visionthreatening retinopathy was 11.8% and macular oedema was 6.9%. There were no racial differences. Significant predictors of any retinopathy were longer duration of diabetes, lower body mass index, being on treatment for hypertension, hypercholesterolaemia and use of diabetic medication. Predictors for vision-threatening retinopathy were younger age, longer duration of diabetes and lower body mass index. Conclusions: The use of one-field non-mydriatic 45 degree photography as a screening tool for diabetic retinopathy resulted in a cohort of which 38.1% had diabetic retinopathy. Risk factors for diabetic retinopathy of this cohort are also presented. Key words: Diabetic retinopathy, Epidemiology, Ethnology, Singapore, Screening