Positive association between low-dose ionizing radiation and cataract risk: results from a meta-analysis

Aims: To comprehensively estimate the association of low-dose ionizing radiation (IR) exposure with cataract risk among radiation-associated staff and patients, a meta-analysis was conducted. Methods: A predefined search was conducted on 61,496 subjects (exposed group = 21,465) from 15 published studies by searching electronic databases and reference lists of relevant articles. Random-effects or fixed-effects model was used to access the overall and stratification effect on Low-dose IR exposure to the risk of cataract as appropriate. Results: We found a significant association between the low-dose IR exposure and the risk of cataract (RR = 1.52, 95% CI: 1.22-1.88). Stratified analysis further detected that both Asian and Caucasian population showed significant associations between low-dose IR exposure and cataract risk (RR = 1.74, 95% CI: 1.18-2.57 for Asian group, RR = 1.38, 95% CI: 1.03-1.84 for Caucasian group, respectively). Different exposed subject group also found significant association (RR = 1.91, 95% CI: 1.22-3.00 for interventional cardiologists, RR = 2.52, 95% CI: 1.71-3.71 for supporting staff and RR = 1.66, 95% CI: 1.22-2.25 for industrial radiographers and patients who had undergone radiation therapy, respectively). In addition, low-dose IR exposure might contribute high risk to posterior subcapsular cataract (RR = 2.41, 95% CI: 1.72-3.38). Conclusion: Our study suggested that the low-dose IR exposure may contribute to cataract development among radiation-associated population, especially to high risk for posterior subcapsular cataract. Further well-designed studies are needed to clarify how relatively low dose of IR exposure promotes progression of cataracts and understanding the requirements of radiation-protection professionals.