The Prevalence of Diabetic Retinopathy Among Known Diabetic Population in Nepal

Background The worldwide prevalence of diabetic retinopathy (DR) was found to be 34.6%. WHO estimates that DR is responsible for 4.8% of the 37 million cases of blindness throughout the world. In a study undertaken in urban population in Nepal, M.D. Bhattarai found the prevalence of diabetes among people aged 20 years and above to be 14.6% and the prevalence among people aged 40 years and above to be 19%. Studies on DR, to our knowledge, have mostly been hospital based in Nepal. Little information is available about prevalence of DR at the community level in Nepal. Objective To investigate the prevalence of diabetic retinopathy and associated risk factors among known diabetic population of Nepal. Method A descriptive cross sectional study was conducted among individuals aged 30 and more using cluster sampling method. The study sites were Kathmandu metropolitan city and Birgunj sub-metropolitan city. A sample size of 5400 was calculated assuming 5% prevalence rate with 95% confidence level, 5% worst acceptable level and 1.5 cluster sampling design effect. Study participants were interviewed, anthropometric measurements and fundus photograph was taken from participants with diabetes. Fundus photographs were used to grade retinopathy. Result Around 12% of the respondents were diabetic, mean age 55.43±11.86 years, of which slightly more than half were females (50.2%). Among these diabetic respondents 9.9% had some forms of diabetic retinopathy, mean age 54.08±10.34 years, 56.7% were male. When severe grade of retinopathy in any eye was considered as overall grade of retinopathy for the individual, prevalence of Non-proliferative Diabetic Retinopathy, Proliferative Diabetic Retinopathy and complete vision loss was found to be 9.1%, 0.5% and 0.3%. Prevalence of Diabetic Macular Edema was 5.5%. Duration of diabetes, family history of diabetes and blood pressure at the day of survey was found to be associated with having any retinopathy. Conclusion Diabetic retinopathy is emerging as a public health threat in Nepal. With increasing diabetes, DR can be expected to increase more. Existing eye care services may require upgrading to provide quality and affordable retinopathy services to address this emerging problem.