Background: India has a high burden of diabetic retinopathy ranging from 12.2% to 20.4% among patients with type 2 diabetes mellitus (T2DM). A T2DM management programme was initiated in the public sector in Tamil Nadu. We estimated the prevalence of diabetic retinopathy and its associated risk factors.
Methods: We did a cross-sectional survey among patients with T2DM attending two primary health centres for treatment and follow-up in Kancheepuram, Tamil Nadu in January- March 2013. We did a questionnaire-based survey, and measured blood pressure and biochemical parameters (serum creatinine, plasma glucose, etc.) of the patients. We examined their eyes by direct and indirect ophthalmoscopy and defined diabetic retinopathy using a modified classification by Klein et al. We calculated the proportion and 95% CI for the prevalence and adjusted odds ratio (AOR) for risk factors associated with diabetic retinopathy.
Results: Among the 270 patients, the mean (SD) age was 54.5 (10) years. The median duration of T2DM was 48 months. The prevalence of diabetic retinopathy was 29.6%. Overall, 65.9% of patients had hypertension, 14.4% had nephropathy (eGFR <60 mg/dl) and 67.4% had neuropathy. Among patients with comorbid conditions, 60%, 48%, 32%, and 3% were already diagnosed to have hypertension, neuropathy, retinopathy, and nephropathy, respectively. The risk factors for diabetic retinopathy were hypertension (AOR 3.2, 95% CI 1.7-6.3), duration of T2DM >5 years (AOR 6.5, 95% CI 3.6-11.7), poor glycaemic control (AOR 2.4, 95% CI 1.4-4.4), and nephropathy (AOR 2.3, 95% CI 1.1-4.6).
Conclusions: There was a high burden of undetected retinopathy and other comorbid conditions among patients with T2DM. Early detection of comorbid conditions and glycaemic control can be improved by training care-providers and educating patients.