This retrospective cohort study involving 934 147 residents of British Columbia (10 827 first-time users of bisphosphonates and 923 320 nonusers) was conducted to examine the risk of inflammatory ocular adverse events in a pharmacoepidemiologic cohort study. The incidence rate among first-time users was 29/10 000 person-years for uveitis and 63/10 000 person-years for scleritis. In contrast, the incidence among people who did not use oral bisphosphonates was 20/10 000 person-years for uveitis and 36/10 000 for scleritis (number needed to harm: 1100 and 370, respectively). First-time users had an elevated risk of uveitis (adjusted RR 1.45; 95% CI 1.25-1.68) and scleritis (adjusted RR 1.51; 95% CI 1.34-1.68). The rate ratio for the propensity-scoreadjusted analysis did not change the results (uveitis RR 1.50 and 95% CI 1.29-1.73; scleritis RR1.53 and 95% CI 1.39-1.70). The authors concluded that people using oral bisphosphonates for the first time might be at a higher risk of scleritis and uveitis compared to people with no bisphosphonate use. Therefore, patients taking bisphosphonates should be familiar with the signs and symptoms of these conditions so that they can immediately seek assessment by an ophthalmologist if necessary. CMAJ. 2012 Apr 2. PMID: 22470169
