Prevalence of Lens Opacities in India: The INDEYE Study

Abstract

Purpose: : To describe the prevalence of lens opacities in older people in India.

Methods: : People aged 60 years and older identified using random cluster-sampling in 2 study centres in north and south India, attended an eye examination. Digital images of lens opacities were graded by type and severity using the Lens Opacity Classification System III (LOCS III). Any cataract was defined as LOCS III ≥4 nuclear, ≥3 cortical and ≥2 posterior subcapsular, or dense ungradeable opacities or previously operated.

Results: : 2821 people (79% response rate) in north India and 3079 (78%) in south India attended an eye examination. The prevalence of any cataract was 73.6% (95% CI 72.0 - 75.2) and similar in the two centres (p=0.2). Type of cataract differed in prevalence between the centres: nuclear 60.0% (95% CI 56.9-63.1) in north India, 48.0% (95% CI 44.8-51.2) in south India; posterior subcapsular 26.5% (95% CI 24.4-28.5) in north India, 21.7% (95% CI 19.5-23.8) in south India; cortical 9.6% (95% CI 8.0-11.2) in north India and 12.8 % (95% CI 11.3-14.3) in south India. Prevalence of any cataract rose with age (54.9%, 95% CI 52.0-57.8 age group 60-64 years; 90.3%, 95% CI 88.9-91.8 age group 70 years and older, p<0.001) and was higher in women than in men (76.7%, 95% CI 74.9-78.5 women; 70.1%, 95% CI 68.0-72.1 men, p<0.001). Similar patterns with age and gender were observed for each type of cataract.

Conclusions: : Cataract prevalence, especially posterior subcapsular cataract, is very high in older Indians compared to comparable age groups in western populations.

Keywords: cataract • clinical (human) or epidemiologic studies: prevalence/incidence