Estimating the proportion of persons with diabetes developing diabetic retinopathy in India: A systematic review and meta-analysis

BACKGROUND: Available evidence from India shows that the control of diabetes is poor in majority of the population. This escalates the risk of complications. There is no systematic review to estimate the magnitude of diabetic retinopathy (DR) in India. MATERIALS AND METHODS: A systematic literature search was carried out in Ovid Medline and EMBASE databases using Mesh and key search terms. Studies which reported the proportion of people with diabetes with DR in a representative community population were included. Two independent reviewers reviewed all the retrieved publications. Data were extracted using a predefined form. Review Manager software was used to perform meta-analysis to provide a pooled estimate. Studies included were assessed for methodological quality using selected items from the STROBE checklist. RESULTS: Seven studies (1999–2014; n = 8315 persons with diabetes) were included in the review. In the meta-analysis, 14.9% (95% confidence interval [CI] 10.7–19.0%) of known diabetics aged ≥30 years and 18.1% (95% CI 14.8–21.4) among those aged ≥50 years had DR. Heterogeneity around this estimate ranged from I(2)= 79–87%. No linear trend was observed between age and the proportion with DR. The overall methodological quality of included studies was moderate. CONCLUSIONS: Early detection of DR is currently not prioritized in public health policies for noncommunicable diseases and blindness programs. Methodological issues in studies suggest that the proportion of diabetics with DR is underestimated in the Indian population. Future research should emphasize more robust methodology for assessing diabetes and DR status.