Risk of cataract for people with tuberculosis: results from a population-based cohort study

BACKGROUND: Tuberculosis (TB) is an infectious disease involving multiple organs, including the eyes. We examined the risk of cataract among patients with TB using population data. METHOD: Using data from the National Health Insurance (NHI) system of Taiwan, we established a TB cohort with 6994 patients newly diagnosed between 2000 and 2010. For each TB patient, four subjects without TB were randomly selected for the non-TB cohort, frequency matched by age, sex and diagnosis years. The incidence of cataract was measured by the end of 2011. The hazard ratio (HR) of cataract was estimated using Cox proportional hazards regression analysis. RESULTS: The overall incidence rate of cataract was 21% greater in the TB cohort than in the non-TB cohort (22.9 vs. 18.8/1000 person-years, P < 0.001), with an adjusted HR (aHR) of 1.26 (95% CI 1.16-1.37). Cataract incidence increased with age, and was higher in men than women and much higher for those with comorbidity. The hazard of cataract was higher in the first 6 months after TB diagnosis. CONCLUSION: TB patients are at elevated risk of developing cataract. Although the incidence decreased with time, the aHR remains statistically significant through the follow-up years.