Abstract TMP90: Advances in Treatment of Central Retinal Artery Occlusion: Potential Efficacy of Systemic Fibrinolysis

Background: Central retinal artery occlusion (CRAO) results in sudden, painless loss of vision in the affected eye which is usually permanent. Despite 150 years of research, there is no treatment which has been proven to be effective to salvage visual acuity. Acute CRAO may also be amenable to treatment with intravenous tissue plasminogen activator (tPA). In the current work, we evaluated the efficacy of intravenous tPA in an ongoing prospective cohort study. Methods: We enrolled 107 patients with acute CRAO within 48 hours of symptoms onset and with a visual acuity of less than 20/200 from January 2009 until now. Those within 6 hours of onset were offered treatment with tPA; this interval was narrowed to 4.5 hours in July 2015 in response to new data. The primary outcomes were safety and functional visual acuity recovery defined as a final visual acuity of 20/100 or better. Results: Twenty-two patients (20.5% of the cohort) were treated with tPA. One patient had an asymptomatic intracerebral hemorrhage after tPA treatment and there were no other adverse events. Thirty-six percent of tPA-treated patients had recovery of visual acuity when treated within 4.5 hours while only 12.5% of patients who were not treated with tPA had recovery of visual acuity (p=0.009). None of the patients treated with tPA between 4.5 and 6 hours after onset (0/8) recovered. The median time to arrival in the ER after onset of symptoms for all patients with acute CRAO was 8.0 hrs (IQR 5.5 to 23), but the median time to initial contact with any provider was 3.9 hrs after onset (IQR 2.0 to 12) meaning a significant fraction of patients with acute CRAO may be candidates for fibrinolysis if they are efficiently routed to emergency departments. Finally we incorporated our results and those of several other recent cohort studies into an updated subject-level meta-analysis to estimate the effect-size of tPA treatment on visual acuity across a broader population and demonstrate the reproducibility of our findings. Conclusions: This study showed that visual outcomes for acute CRAO are greatly improved with tPA treatment and this treatment can be feasibly applied to a high percentage of affected patients. The results of our study strongly support proceeding to a clinical trial.