Is Intravenous Thrombolysis Safe and Effective in Central Retinal Artery Occlusion? A Critically Appraised Topic

Central retinal artery occlusion (CRAO) is a neurological and ophthalmologic emergency associated with poor visual recovery. There is a dilemma regarding the appropriate treatment, as formal guidelines are lacking. Despite being considered an ocular equivalent of cerebral infarction, the time window of intravenous (IV) thrombolysis administration for maximum efficacy and safety in CRAO remains uncertain.

To critically assess the current evidence regarding the safety and effectiveness of IV thrombolysis in the treatment of patients with CRAO.

The objective was addressed through the development of a critically appraised topic that included a clinical scenario, structured question, literature search strategy, critical appraisal, assessment of results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and resident neurologists, a medical librarian, and content experts in the fields of vascular neurology and ophthalmology.

A recent patient-level meta-analysis was selected for critical appraisal. The study compared the visual recovery rates after IV thrombolysis in CRAO against the natural history of this illness and conservative therapies (ocular massage, anterior chamber paracentesis, and/or hemodilution). Time to thrombolytic therapy administration had a significant impact on visual recovery in CRAO (P<0.001). IV thrombolysis within the first 4.5 hours after symptom onset resulted in recovery of vision in 50.0% of the patients [95% confidence interval (CI), 32.4%-67.6%]. The rate of visual recovery was nearly 3 times higher than in the natural history cohort [odds ratio, 4.7 (95% CI, 2.3-9.6); P<0.001], with a 32.3% absolute risk reduction and a number needed to treat of 4.0 (95% CI, 2.6-6.6). There was no significant difference in the recovery rate after thrombolysis compared with the natural history cohort for those patients treated after 4.5 hours. No major hemorrhages occurred after alteplase administration in this meta-analysis.

IV thrombolysis in CRAO seems to be safe and effective within the first 4.5 hours of symptom onset. A clinical decision based on this meta-analysis alone cannot be made due to several limitations. A randomized controlled clinical trial of early IV alteplase administration in CRAO is necessary to provide evidence-based therapeutic guidance.