The association between exposure to radiation and the incidence of cataract

Objective: To examine the association between exposure to radiation from computed tomography (CT) studies and the incidence of cataract. Methods: In a nested case–control study, all cataract cases and their matched controls were sampled from a retrospective cohort of Israeli residents who underwent CT scans or ultrasonic tests in Soroka Medical Center, Beer-Sheva, Israel, between the years 1996 and 2014. The risk of cataract associated with head, neck or the rest of the body CT was assessed using Poisson survival analysis. Results: The nested matched sample included 3841 cataract cases and their age- and sex-matched controls (n = 228,743). CT radiation exposure was more frequent in the cataract group, with 9.7% head CT, 1.2% neck CT and 6.6% other CT, compared to 5%, 0.7% and 3.7% among person-years without cataract (p < 0.001). In a multivariate analysis, a similar increased risk of cataract associated with head (hazard ratio (HR): 1.24, 95% confidence interval (CI): 1.11; 1.38) and other CT (HR: 1.25, 95% CI: 1.10; 1.43) was found. No association with neck CT (HR: 1.07, 95% CI: 0.80; 1.43) was observed. Conclusion: In our study population, a similar risk of cataract with head, neck or the rest of the body CT was detected.