Risks and benefits of anticoagulant and antiplatelet medication use before cataract surgery

Objective: To estimate the risks and benefits associated with continuation of anticoagulants or antiplatelet medication use before cataract surgery. Design: Prospective cohort study. Participants: Patients 50 and older scheduled for 19,283 cataract surgeries at nine centers in the United States and Canada between June 1995 and June 1997. Intervention: None. Main Outcome Measures: Intraoperative and postoperative (within 7 days) retrobulbar hemorrhage, vitreous or choroidal hemorrhage, hyphema, transient ischemic attack (TIA), stroke, deep vein thrombosis, myocardial ischemia, and myocardial infarction. Results: Before cataract surgery 24.2% and 4.0% of patients routinely used aspirin and warfarin, respectively. Among routine users, 22.5% of aspirin users and 28.3% of warfarin users discontinued these medications before surgery. The rates of stroke, TIA, or deep vein thrombosis were 1.5/1000 among those who did not use aspirin or warfarin and 3.8/1000 surgeries among routine users of aspirin and warfarin who continued their medication before surgery. The rate was 1 event per 1000 surgeries among those who discontinued aspirin use (relative risk = 0.7, 95% confidence interval = 0.1-5.9). There were no events among warfarin users who discontinued use. The rates of myocardial infarction or ischemia were 5.1/1000 surgeries (aspirin) and 7.6/1000 surgeries (warfarin) among routine continuous users and no different from those of routine users who discontinued use. Conclusions: The risks of medical and ophthalmic events surrounding cataract surgery were so low that absolute differences in risk associated with changes in routine anticoagulant or antiplatelet use were minimal.