Risk factors for cataract in India: the INDEYE study

Abstract

Abstract Purpose To describe the prevalence of lens opacities and to assess risk factors 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 using the Lens Opacity Classification System III. To identify lifestyle and environmental factors associated with lens opacities, assessment of different potential risk factors was performed, with a focus on cooking fuels, tobacco and alcohol use, sunlight exposure, diet and antioxidant blood levels. Results 2821 people in north India and 3079 in south India attended an eye examination. The prevalence of any cataract was 73.6% and similar in the two centres (p=0.2). Type of cataract differed in prevalence between the centres: nuclear 60.0% in north India, 48.0% in south India; posterior subcapsular 26.5% in north India, 21.7% in south India; cortical 9.6% in north India and 12.8 % in south India. Prevalence of any cataract rose with age (54.9%, age group 60‐64 years; 90.3%, age group 70 years and older, p<0.001) and was higher in women than in men (76.7%, women; 70.1%, men, p<0.001). Similar patterns with age and gender were observed for each type of cataract. Among risk factors, tobacco use, exposure to cooking fuels and antioxidants levels were significantly associated with cataract (p<0.001). Conclusion Cataract prevalence, especially posterior subcapsular cataract, is very high in older Indians compared to comparable age groups in western populations. Factors as tobacco use, exposure to cooking fuels and low antioxidant blood levels may in part explain the high prevalence of cataract in this population.