Risk of cataract and history of severe diarrheal disease in southern India.

A case-control study was carried out in the state of Tamil Nadu, southern India, to examine the association between the risk of visually disabling cataract and a lifetime history of severe diarrhea (including cholera). A series of 421 subjects, aged 35 to 65 years, meeting case (n = 181) and control (n = 240) eligibility criteria were enrolled from 19 rural cataract-screening camps. Ninety case-control pairs were postmatched for (reported) age (+/- 2 years), sex, and area of residence. A history of diarrhea was obtained by using an algorithm developed by other investigators in India who have reported a strong association between cataract and diarrhea. An odds ratio of 0.8 (95% confidence limits: 0.0, 3.2) was obtained from matched pairs analysis, and an odds ratio of 1.3 (95% confidence limit: 0.6, 2.7) was obtained among all subjects (n = 392) from a logistic analysis that adjusted for age, sex, occupation, area of residence, and caste. Findings of this study do not support the hypothesis of an increased risk of visually disabling cataract in persons with a positive history of severe diarrhea.