Estimating the magnitude of diabetes mellitus and diabetic retinopathy in an older age urban population in Pune, western India

Objective To estimate magnitude of diabetes mellitus (DM) and diabetic retinopathy (DR) in a high risk population in Pune, western India. Methods DR module in rapid assessment of avoidable blindness (RAAB) survey methodology was used. Sample size of 3527 was calculated based on estimates from previous studies in India. A certified RAAB trainer conducted a training of survey teams. Random cluster sampling with probability proportionate to size was adapted to select 60 clusters consisting of 60 individuals each. Two teams visited door to door until they finished visiting 60 persons each day. Visual acuity testing, torch light examination, red glow test were carried out to determine persons with visual impairment and its cause. Every participant then underwent a random blood sugar level testing. All diabetics (known and newly detected) underwent dilated retina evaluation with indirect ophthalmoscopy to determine their DR status. Data were entered into RAAB6 software and descriptive statistics generated. Results Response rate was 89.5 % (3221/3600), females (55.3%). The prevalence of DM in the sample was (706/3221) 21.9 %(95 CI 20.1 to 23.7). Prevalence of DR was 14.3 % (95% CI 11.7 to 16.9). Most diabetics (401/579, 69.3%) never had an eye examination for DR in the past. Cataract was the principal cause of blindness (50 % cases) among diabetics. Conclusion DM affects over fifth of persons above 50 years of age in western India. Nearly seventh of the diabetics have DR, but coverage of screening is poor in Pune.