Epidemiology of the Association between Anticoagulants and Intraocular Hemorrhage in Patients with Neovascular Age-Related Macular Degeneration

Purpose: To determine the cumulative and annual incidence of intraocular hemorrhage (subretinal hemorrhage or vitreous hemorrhage) in patients with neovascular age-related macular degeneration (neovascular AMD) and association with daily antiplatelet or anticoagulant (AP/AC) medication usage (aspirin, clopidogrel and warfarin), age, gender, hypertension, diabetes mellitus or bilateral neovascular AMD. Design: Retrospective, cross-sectional study in a tertiary University setting. Methods: Data on one hundred and ninety-five eyes of 195 patients without prior intraocular hemorrhage examined over seventy-three months was reviewed. Results: Ninety-six of 195 (49.2%) patients were taking daily AP/ACs. 63.5% of patients taking daily AP/AC agents had hemorrhage compared to 29.2% of patients not taking (OR= 4.21, 95% CI=1.42-8.46, p<0.001). The overall annual incidence of intraocular hemorrhage was 0.14% per year. Among patients taking daily AP/AC, the cumulative incidence (61/96, 63.5%) and annual incidence (0.10%) of concurrent intraocular hemorrhage was significantly greater compared to patients not taking them (29/99, 29.2% and 0.04%, respectively, p<0.0001). Fourteen of 18 (77%) patients taking more than one daily AP/AC had occurrence of intraocular hemorrhage. AP/AC usage was an independent risk factor for the development of intraocular hemorrhage. The use of any agent resulted in a significantly increased risk of developing intraocular hemorrhage. Additionally, presence of bilateral neovascular AMD was a significant association in those taking daily AP/ACs, whereas age was a significant association in those not taking daily AP/AC agents. Conclusions: All three daily AP/AC types were significantly associated with an increased risk of the development intraocular hemorrhage in patients with neovascular AMD, whereas gender, hypertension and diabetes were not. Age was not significantly associated with hemorrhage in patients taking daily AP/AC agents whereas the presence of bilateral neovascular AMD was. These findings indicate that the AP/AC use may predispose neovascular AMD patients to intraocular hemorrhage more so than age and duration of disease alone. While the risk that discontinuing these medicines would pose to the patients' health may be too great to justify, ensuring that an appropriate medication dosage is maintained should be a priority within this patient population.