Aspirin use in central retinal arterial occlusion to prevent ischaemic stroke: A retrospective cohort study in Taiwan

Objective To understand the efficacy of aspirin use for preventing ischaemic stroke after central retinal artery occlusion (CRAO). Design The retrospective cohort study was conducted using the National Health Insurance Research Database from 1998 to 2013. Setting A population-based study. Participants A total of 9437 participants with newly diagnosed CRAO were identified. Participants who had a previous stroke and/or retinal vascular occlusion, were aged <20 years and used aspirin 3 months before the event were excluded. There were 3778 eligible participants matched by propensity score, and they were divided into aspirin (n=434) and aspirin-naive (n=1736) groups after the matching. Methods Cox proportional hazard models and cumulative survival curves were used to assess ischaemic stroke in the study groups, along with log-rank tests to compare group differences. Main outcome measures Incidence of ischaemic stroke in the aspirin and aspirin-naive groups 1 year after CRAO. Results Of the 3778 patients with newly diagnosed CRAO, 151 (4%) had a subsequent ischaemic stroke within 1 year. The risk was especially high during the first week of the CRAO. No difference between the aspirin and aspirin-naive groups was found in risk of ischaemic stroke, haemorrhagic stroke, gastrointestinal bleeding, major bleeding, acute coronary syndrome, retinal vein occlusion, new-onset glaucoma, undergoing panretinal photocoagulation or all-cause mortality. Risk factors for ischaemic stroke within 1 year of CRAO included male gender (p=0.031; HR=1.46) and age (p=0.032; HR=1.14). Conclusions Aspirin use after a CRAO showed no benefit on attenuating the risk of ischaemic stroke. The risk of ischaemic stroke was increased after CRAO especially during the first week. Male gender and age were risk factors for ischaemic stroke after CRAO.