Risk of acute stroke in patients with retinal artery occlusion: a systematic review and meta-analysis

Objective To estimate the incidence of acute cerebral ischaemia detected by magnetic resonance imaging (MRI) in acute central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO) and transient monocular vision loss (TMVL). Methods Studies reporting the incidence of acute cerebral ischaemia, detected by MRI, within 7 days from diagnosis of acute CRAO, BRAO and TMVL up to January 2019 were systematically searched for on Pubmed, Medline and Cochrane Library. Meta-analysis was performed using random effects model. The primary outcome was the pooled estimate of incidence of acute cerebral ischaemia in CRAO, BRAO and TMVL cohorts including both neurologically symptomatic and asymptomatic patients, expressed as a proportion along with 95% confidence intervals (CIs). The pooled estimate of incidence of asymptomatic acute cerebral ischaemia represented a secondary outcome measure. Results For the primary outcome, the pooled proportion of acute cerebral ischaemia was 0.30 (CI 0.24-0.36) in the CRAO cohort, and 0.25 (CI 0.16-0.37) in the BRAO cohort, without statistical heterogeneity. The rate of acute cerebral ischaemia was 11.8% in the TMVL cohort. For the secondary outcome, the pooled proportion of asymptomatic acute cerebral ischaemia was 0.22 (CI 0.16-0.28) in the CRAO cohort, 0.29 (CI 0.20-0.41) in the BRAO cohort and 0.08 (CI 0.05-0.15) in the TMVL cohort, with no statistical heterogeneity. Conclusions 30% of patients with acute CRAO and 25% of patients with acute BRAO presented an acute cerebral ischaemia on MRI. Such high rates support a care pathway of prompt referral of such patients for neurological evaluation and brain imaging.