Prevalence of ocular hemorrhage in patients receiving warfarin therapy

Background: Warfarin, the drug most commonly used for outpatient anticoagul ation therapy, has bleeding as its main side effect. The objective of this study was to determine the prevalence of ocular hemorrhage in patients rece iving warfarin and to compare it to the prevalence in the general populatio n. Methods: Patients receiving warfarin therapy who were attending the anticoa gulation clinic at a tertiary care hospital in Montreal between October and December 1996 received a flyer inviting them to have their eyes examined t o look for "ocular bleeding." Consenting patients were examined for subconj unctival hemorrhage, gross hyphema, and vitreous and retinal hemorrhages th rough external ocular examination and funduscopic examination with the pupi ls dilated using direct and indirect ophthalmoscopy. Results: Of the 1225 patients seen at the clinic 126 (10%) agreed to partic ipate. Four patients (3%) were found to have intraretinal hemorrhage at the time of examination, All hemorrhages were visually insignificant. Interpretation: The risk of retinal hemorrhage in patients without preexist ing ocular disease, such as retinal neovascularization or choroidal vasculo pathy, who are receiving warfarin therapy is so small that it should not de ter physicians from prescribing this drug when indicated.