Use of topiramate and risk of glaucoma: a case-control study.

PURPOSE: To examine the possible link of acute-onset glaucoma with topiramate.

DESIGN: Case-control study.

METHODS: A case-control study was conducted among a cohort of subjects who had visited an ophthalmologist in the Province of British Columbia, Canada from 2000 to 2007. Cases were identified as those newly diagnosed with glaucoma (ICD-9 360). For each case, 5 controls were selected and matched to the cases by age and calendar time using density-based sampling. Crude and adjusted rate ratios (RRs) for current and past use of topiramate were computed. As a sensitivity analysis, the risk of glaucoma with a positive control drug (an oral steroid) and a negative control drug (inhaled albuterol) was also assessed.

RESULTS: From the initial cohort of 989 591 subjects, 178 264 cases of glaucoma and 891 320 controls were identified. There was a slight increase in the risk of glaucoma among current users of topiramate (RR = 1.23 [95% confidence interval (CI), 1.09-1.40]). This risk was further elevated among new users of the drug (RR = 1.54 [95% CI, 1.09-2.17]). No increase in the risk of glaucoma requiring drug therapy was observed among current topiramate users (RR = 1.09 [95% CI, 0.80-1.61]).

CONCLUSION: We found an increase in the risk of glaucoma with first-time users of topiramate. Future studies are needed to confirm these findings.