Burden of blindness and visual impairment associated with corneal opacities in India.

Purpose: To obtain national-level data on current burden of blindness and visual impairment (VI) due to corneal opacities (CO) and their epidemiological determinants in India.

Methods: A cross-sectional, population-based survey was conducted in 31 districts for population aged ≥50 years using Rapid Assessment of Avoidable Blindness (RAAB) V.6 methodology and 6 districts for population aged 0-49 years. Using standardised definitions, prevalence (95% CIs) and burden for 2023 were estimated at International Classification of Diseases-11 thresholds of mild/early VI (EVI) and moderate to severe VI (MSVI) and blindness.

Results: 85 135 participants aged ≥50 years and 13 695 participants between 0 and 49 years were examined. Prevalence of avoidable blindness due to CO was 17.1 per 10 000 (13.4 to 21.9) and 3.39 per 10 000 (1.16 to 9.92) in populations aged ≥50 years and 0-49 years, respectively. 32% (n=49) in ≥50-year group did not have perception of light in CO-affected eye. Prevalence of cumulative avoidable MSVI or blindness due to CO was 26.9/10 000 (20.7 to 35.0) and 8.32/10 000 (2.81 to 24.62) in populations aged ≥50 years and 0-49 years, respectively, while cumulative avoidable EVI, MSVI or blindness due to CO were 30.1/10 000 (23.8 to 38.1) and 8.3/10 000 (2.81 to 24.62), respectively.Higher prevalence of avoidable MSVI or blindness due to CO were associated with increasing age, lower educational status; lower prevalence was noted in northeast geographical zone. Rural-urban and gender-based differences were not statistically and clinically significant respectively.

Conclusion: There is a high burden of CO-related blindness and VI in India, especially in older populations. Key epidemiological risks may be used for prioritisation in eye health plans.