title: Use of topiramate and risk of glaucoma: a case-control study.
abstract: OBJECTIVE
  To examine the possible link of acute-onset glaucoma with topiramate.
  
  
  METHODS
  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]).
  
  
  CONCLUSIONS
  We found an increase in the risk of glaucoma with first-time users of topiramate. Future studies are needed to confirm these findings.
authors.affiliation: Center for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Canada. mahyar.etminan@vch.ca
authors.forename: Mahyar
authors.initials: M
authors.lastname: Etminan
authors.forename: David
authors.initials: D
authors.lastname: Maberley
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Mikelberg
mesh_terms: D000208:Acute Disease; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects*; D001955:British Columbia; D016022:Case-Control Studies; D016208:Databases, Factual; D004827:Epilepsy / Q000188:drug therapy; D005260:Female; D005632:Fructose / Q000009:adverse effects / Q000031:analogs & derivatives*; D015812:Glaucoma, Angle-Closure / Q000139:chemically induced*; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D012307:Risk Factors; D000077236:Topiramate
chemical_list: D000927:Anticonvulsants; D000077236:Topiramate; D005632:Fructose