Risk of Stroke Recurrence Following Isolated Retinal Artery Occlusion Versus Minor Stroke or Transient Ischemic Attack.

Background: Retinal artery occlusion (RAO) is a form of ischemic stroke per the American Heart Association, yet high-level evidence guiding management and prognostication is limited. The risk of future cerebral infarction following nonarteritic isolated RAO (iRAO; without concomitant cerebral infarction) is unclear. This study compares the risk of stroke recurrence following iRAO versus nondisabling ischemic cerebrovascular events (NICEs), including transient ischemic attacks and minor ischemic strokes.

Methods: This was a retrospective cohort study using the 2016 to 2022 Nationwide Readmissions Database in the United States. Adults hospitalized primarily for RAO or NICE were included. Patients who were functionally dependent at discharge had moderate to severe stroke (National Institutes of Health Stroke Scale score >4), arteritis, or vasculitis, or RAO and concomitant cerebral infarction were excluded from the primary analysis. Two-to-one propensity score matching was performed to balance baseline characteristics between cohorts. The primary outcome was subsequent cerebral infarction within 300 days. Cox regression models and multivariable adjustments were used to estimate hazard ratios.

Results: A total of 1 673 145 patients hospitalized for nondisabling stroke, transient ischemic attack, or RAO were identified; 17 388 (1.0%) had RAO, of whom 4507 (25.9%) had concomitant cerebral infarction and were excluded for primary analyses. After applying additional exclusion criteria and propensity score matching, 11 185 patients with nonarteritic iRAO and 22 757 patients with NICE remained. Patients with iRAO had a significantly lower risk of subsequent cerebral infarction (hazard ratio, 0.26 [95% CI, 0.20-0.35]; P<0.001). Absolute cerebral infarction rates at 30, 90, and 180 days were lower in patients with iRAO versus patients with NICE (0.5% versus 2.3%, 0.8% versus 3.1%, and 1.2% versus 4.3%, respectively; all P<0.001 for all).

Conclusions: Nonarteritic iRAO events were associated with significantly lower risks of subsequent cerebral infarction compared with NICE. These findings suggest that iRAO events are not equivalent to ischemic cerebrovascular events in terms of risk of subsequent stroke. Further studies are needed to optimize secondary stroke prevention strategies tailored to nonarteritic iRAOs.