Prevalence of lens opacities in Northern India

Abstract

Abstract: : Purpose:To obtain estimates of the prevalence by type of lens opacities in the Indian setting. Methods:1443 people (median age 60 years), 52% women, were identified from enumeration of the 50+ age group age in 11 randomly sampled villages from a peri–urban district of Haryana, North India. 87 % attended an eye examination. Two different systems were used for lens image capture: Neitz CT–S for acquiring digitised images of cortical and posterior subcapsular opacities and Topcon SL–7E Photo Slit Lamp Cameras for nuclear opacities. Images were graded using LOCS II. The prevalence of opacities was based on grade in the worst eye and opacities were categorised according to a grade 2 or more for nuclear or cortical and grade 1 or more for posterior subcapsular opacities. Confidence limits took account of the survey design. Results:1061 people were graded for type of opacity; a further 173 were previously operated or had dense opacities which could not be graded. Nuclear opacities were the most common type with an overall prevalence of 56.9% (95% CI 53.0%, 60.6%) in the 50+ population. Posterior subcapsular opacities occurred in 30.3% (95% CI 25.9%, 35.2%) and cortical opacities in 21.6% (95% CI 17.9%, 25.8%). Prevalence rose steeply with age for all opacities. The prevalence of any type of lens opacity including operated cases and ungradeable dense opacities was 76.6% (95% CI 72.7%, 80.1%). Conclusions:These results provide photographically documented evidence of the high prevalence of lens opacities in the Indian population.

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