Central Retinal Artery Occlusion: A Review of Pathophysiological Features and Management

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke that results in painless vision loss attributable to retinal infarction. A keen understanding of clinical presentation and underlying pathophysiological features is key to timely intervention and development of new treatment modalities. In CRAO, the time between initial insult to presentation is significant because, analogous to ischemic stroke, the duration of ischemia is inversely related to viable retinal tissue. A major challenge in CRAO is delayed presentation, which reduces the amount of salvageable retina. In addition, imaging techniques to effectively identify a retinal penumbra, or retinal tissue that is reversibly damaged, are not well established. To compile this narrative review, we conducted a systematic search of the PubMed database to identify relevant articles on the pathophysiological features and treatment of CRAO, including reviews, meta-analyses, clinical studies, observational trials, and randomized trials. The search strategy included the following keywords: central retinal artery occlusion, CRAO, treatment, management, review, meta-analysis, clinical study, observational trial, and randomized trial. We also searched for ongoing clinical trials related to CRAO on ClinicalTrials.gov. The identified articles and studies were then carefully evaluated for their relevance to the topic and used in compiling this review. Intravenous thrombolysis is a compelling therapeutic approach, with current limited data suggesting early intervention (4.5 hours of symptom onset) results in better patient outcomes. However, ongoing trials assessing and comparing different fibrinolytic agents, routes of administration (venous versus arterial), and timing of intervention will provide further insight on the efficacy of this treatment modality. In parallel, development and testing of imaging techniques aimed at quantifying retinal blood flow and assessing tissue viability could improve risk stratification to guide treatment. These can then be used in conjunction to guide use of conventional therapies, neuroprotectants, and thrombolytics for the management of various CRAO presentations that can be effectively deployed in emergency settings. This article provides a narrative review of pathophysiological features, risk factors, and current and emerging management techniques of CRAO.