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

To estimate the risks and benefits associated with continuation of anticoagulants or antiplatelet medication use before cataract surgery.Prospective cohort study.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.None.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.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.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.