The Kerala Study (Nayanamritham project)
Kerala is the most advanced state in India in terms of literacy, economic progress, social uplift and demographic transition but is known as the diabetes capital of India. The prevalence of diabetes can be as high as 20% ─ double the national average of 8%. The prevalence of diabetic retinopathy among the diabetic population is ~ 18%. Currently, there is no systematic diabetic retinopathy screening programme in the public sector.
The Kerala study, a collaboration between the UK and the Government of Kerala, will evaluate the effectiveness of introducing screening and treatment pathways for diabetic retinopathy in the public system in Kerala by adapting diabetic retinopathy care pathways in developed countries to local needs and resources. The research team will introduce a complex intervention of screening for diabetic retinopathy at the primary care level, laser treatment at district hospitals and complex referrals to the tertiary centres by increasing research and service capacity and capability. The quality and delivery of the intervention will also assessed at each sector of the care pathway to evaluate whether the study is delivered as intended.
This pilot study will take place within the public health system in Thiruvananthapuram and will inform the roll-out of the diabetic retinopathy care pathway throughout the Kerala State.

Family Health Centres in Thiruvananthapuram district taking part in the pilot study
Results from the Kerala Study
The study aimed to estimate the prevalence of diabetic retinopathy and its risk factors in people with diabetes in the non-communicable disease registers who were attending the family health centres in the Thiruvananthapuram district in Kerala. This cross-sectional study was conducted over 12 months in 2019 within the framework of a pilot district-wide teleophthalmology diabetic retinopathy screening programme. The age- and gender-adjusted prevalence of any diabetic retinopathy and sight-threatening diabetic retinopathy in the whole sample, considering socio-demography, lifestyle and known clinical risk groups, are reported.
A total of 4527 out of 5307 (85.3%) screened in the family health centres had gradable retinal images in at least one eye. The age and gender standardised prevalence for any diabetic retinopathy was 17.4% (95% CI 15.1, 19.7), and sight threatening diabetic retinopathy was 3.3% (95% CI 2.1, 4.5). Ages 41–70 years, males, longer diabetes duration, hyperglycaemia and hypertension, insulin users and lower socio-economic status were associated with both DR outcomes.
The burden of diabetic retinopathy and its risk factors in this study highlights the need to implement diabetic retinopathy screening programs within primary care to reduce health inequality.