Prevalence of blindness in India: A systematic review and meta-analysis

Background: The National Programme for Control of Blindness and Visual Impairment modified the definition of blindness in 2017 in line with the internationally accepted definition. We did a systematic review and meta-analysis to compute pooled estimate of blindness in India among adults aged 50 years and above by using recent and old definitions of blindness. Methods: We retrieved population-based studies/surveys reporting the prevalence of blindness using recent (presenting vision <3/60 better eye) and previous (presenting vision <6/ 60 better eye) definitions in India during 1990-2017 from key search engines and grey literature. Two authors did an independent literature search and extracted relevant information. Pooled prevalence estimates were computed using Stata 12.0 by using the random effects model. Forest and funnel plots were generated. Stratification of results was also performed using two time periods: 1995-2005 and 2006-17. Results: A total of 18 published articles/reports were included for recent and 20 for previous definitions of blindness, involving 211 502 participants. The pooled prevalence (95% confidence interval CI) obtained for recent and previous definitions of blindness in India was found to be 6.11% (5.07%-7.14%) and 9.91% (8.57%-11.25%), respectively. The stratified pooled prevalence (95% CI) from rapid surveys was 4.81% (3.26%-6.35%) and 4.68% (2.91%-6.46%) for studies published during 1995-2005 and 2006-17, respectively, using the new definition. The corresponding figures for comprehensive surveys were 9.22% (95% CI 6.48%-11.96%) for the period 1995-2005 and 3.81% (95% CI 2.76%-4.84%) for the period 2006-17. Conclusion: There is a decrease in the prevalence of blindness in India using recent and previous definitions and a declining trend over time. High quantum of blindness remains an unfinished public health agenda for implementing programmes in larger populations to reduce its burden.