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.