Glaucoma Blindness and Visual Impairment in India: Findings From the National Blindness Survey

Potentially avoidable blindness due to glaucoma affects 10.4/10000 Indian adults aged ≥50 years. Early detection may prevent vision impairment. Nearly half of the people with unilateral glaucoma-associated vision loss have no perception of light in the affected eye.

We aimed to estimate the population prevalence and number of persons visually impaired (VI) due to glaucoma in India.

Deidentified data from the National Blindness Survey 2015-19 in the population aged ≥50 years were analyzed to estimate vision loss due to glaucoma. Diagnosis was based on optic disc assessments. Prevalence (95% CIs), risk factors (odds ratios, ORs), and burden for 2023 were estimated using thresholds for presenting visual acuity (PVA) in the better eye: <6/18 for moderate-severe visual impairment (MSVI) and <3/60 for blindness.

Eighty-five thousand one hundred thirty-five participants aged ≥50 years were examined, and glaucoma was the cause of VI in 485 (59.6/10000; 95% CI: 47.6-74.7) participants and the most avoidable cause of VI in 181 participants (22.6/10000; 95% CI: 18.1-28.2). This included 96 with blindness (10.4/10000; 95% CI: 7.7-13.8) and 64 with MSVI (8.2/10000; 95% CI: 5.4-12.5). Among 304 with unilateral glaucoma-associated vision loss, 49.3% had no perception of light in the affected eye. Prevalence of avoidable glaucoma MSVI or blindness increased from 11.2/10000 in 50-59 years to 23.7/10000 in 70-79 years age group (adjusted OR 1.8; 95% CI: 1.0-3.0) and was associated with illiteracy ( OR =2.6; 95% CI: 1.2-5.7) and residence in Northern zone of India ( OR =2.9, 95% CI: 1.7-4.8) but not with sex or rural residence.

There is a significant burden of vision impairment and blindness caused by glaucoma in India, which needs redressal through policy and programmatic interventions.