Antithrombotic Medications and Intraocular Hemorrhage Risk in Exudative Age-Related Macular Degeneration.

Importance: Although the use of anticoagulants or antiplatelets is known to increase bleeding risk, there is limited evidence on whether they contribute to a higher incidence of intraocular hemorrhage in patients with age-related macular degeneration (AMD). Objective: To examine the association between anticoagulant or antiplatelet use and clinically important intraocular hemorrhage requiring vitrectomy in patients with exudative AMD. Design, Setting, and Participants: In this nationwide, population-based, retrospective cohort study using the Korean Health Insurance Review and Assessment Service database, 149 620 patients with exudative AMD older than 40 years were identified from May 1, 2014, to April 30, 2023. Exposures: Use of anticoagulants or antiplatelets. Main Outcomes and Measures: The main study outcome was clinically important intraocular hemorrhage requiring vitrectomy. The analysis used a retrospective, longitudinal cohort study design using Cox proportional hazards regression analysis and Kaplan-Meier survival analyses (exposure vs nonexposure group) and a cross-sectional case-control study design using logistic regression analysis (hemorrhage vs no hemorrhage group). All analyses were adjusted for demographics and comorbidities. Results: A total of 94 449 patients (mean [SD] age, 71.8 [9.8] years; 55 677 [59.0%] male) were included in the cohort study, and 8110 patients (mean [SD] age, 70.2 [9.6] years; 5090 [62.8%] male) were included in the case-control study. In the Cox proportional hazards regression analysis, anticoagulant or antiplatelet exposure was associated with a higher risk of intraocular hemorrhage requiring vitrectomy (adjusted hazard ratio, 1.15; 95% CI, 1.02-1.29). The incidence probability of intraocular hemorrhage requiring vitrectomy was higher in the exposure group than the nonexposure group. In the logistic analysis, the use of anticoagulants (adjusted odds ratio [aOR], 1.88; 95% CI, 1.45-2.44) or antiplatelets (aOR, 1.37; 95% CI, 1.19-1.57) was associated with intraocular hemorrhage requiring vitrectomy. The combined use of anticoagulants and antiplatelets showed the highest aOR (aOR, 2.28; 95% CI, 1.65-3.15). Higher medication adherence was also associated with a higher aOR of intraocular hemorrhage (aOR, 1.69; 95% CI, 1.45-1.97). Conclusions and Relevance: In this nationwide cohort study of patients with exudative AMD, antithrombotic medications were associated with a higher risk of intraocular hemorrhage requiring vitrectomy. These results suggest the need for proactive communication and tailored monitoring strategies to help minimize such sight-threatening complications.