The association of stroke with central and branch retinal arterial occlusion

Objectives: To determine the near-term risk of stroke following a retinal artery occlusion (RAO).

Methods: The risk of stroke was assessed in two manners; with a self-controlled case series (SCCS) and a propensity score (PS) matched cohort study using a US medical claims database. The date of RAO diagnosis was assigned as the index date. In the SCCS, incidence of stroke was compared in 30- and 7-day periods pre- and post-index date. In PS analysis, matched cohorts were created from patients with RAO or hip fracture. Cox proportional hazard regression assessed the hazard for stroke. Patients were censored at 1 year, upon leaving the insurance plan or if they had a qualifying event for the comparison group.

Results: The SCCS included 16,193 patients with RAO. The incidence rate ratio (IRR) of new stroke in the month after RAO was increased compared to all periods >2 months before and all months after the index date (IRRs: 1.68-6.40, p < 0.012). Risk was increased in the week immediately following the index date compared to most weeks starting 2 weeks prior to and all weeks immediately after the index date (IRRs: 1.93-29.00, p < 0.026). The PS study analysed 18,213 propensity-matched patients with RAO vs. hip fracture. The HR for having a stroke after RAO compared to a hip fracture was elevated in all analyses (All RAO HR: 2.97, 95% CI: 2.71-3.26, p < 0.001; CRAO HR: 3.24, 95% CI: 2.83-3.70, p < 0.001; BRAO HR: 2.76, 95% CI: 2.43-3.13, p < 0.001).

Conclusions: The highest risk for stroke occurs in the days following a CRAO or BRAO, supporting guidelines suggesting immediate referral to a stroke centre upon diagnosis.