Associations between use of mood stabilizers and risk of cataract: A population-based nested case-control study

Background The aim of this study was to investigate whether use of mood stabilizers (MS) is associated with an increased risk of cataract development. Methods We conducted a nested case-control study using National Health Insurance Research Database in Taiwan. A total of 14,288 patients with bipolar disorder (BD) and schizophrenia were included; 7651 in the cataract group and 6637 in the control group. Based on overall cumulative period of MS (lithium, carbamazepine, valproate, and lamotrigine) treatment, we categorized into following groups: no use, and duration < 1 year, 1 to 2 years, and > 2 years. Conditional logistic regression analysis was used to explore the association between use of MS and risk of cataract development. Results The risks for cataract development were significantly higher in patients using lithium alone and lithium combined with other MS for more than 2 years (adjusted odd ratio [AOR] = 1.39; 95% CI = 1.01–1.92, p = 0.043 and AOR = 1.44; 95% CI = 1.13–1.85, p = 0.003, respectively) than in non-users. Furthermore, the risks of cataract development increased in those treated with valproic acid combined with other MS (AOR = 1.26; 95% CI = 1.02–1.57, p = 0.035). Finally, no increased risks of cataract development were found in carbamazepine and lamotrigine users. Conclusions We found increased risks of cataract development in long-term users of lithium, lithium combined with other MS and valproic acid combined with other MS for more than two years among patients with BD and schizophrenia.