Abstract Body: Background and Objectives: Central retinal artery occlusion (CRAO) is a rare form of acute ischemic stroke that causes severe visual loss, which is a relatively rare emergency but devastating eye condition. There is currently no guideline-endorsed treatment for CRAO. Data on hyperbaric oxygen therapy (HBOT) for CRAO is minimal. We aim to investigate the benefit of HBOT in patients with CRAO compared to conservative management.

Methods: We conducted a retrospective single-center study that recruited patients with diagnosed non-arteritic CRAO from January 2019 to May 2024. HBOT was offered to CRAO patients who presented to the emergency room within 24 hours from symptom onset. Eight patients underwent a full course of HBOT (twice a day for five days with a total of 10 HBO treatments). Twelve CRAO patients received partial HBOT (from 1 to 7 treatments); HBOT was discontinued per patients' request, either due to anxiety or no noted visual improvement. Twenty-seven CRAO patients did not undergo HBOT due to being outside of the treatment window or HBOT was declined by patients. The primary outcome was visual improvement at the time of discharge. Student's T-test and Chi-square test were used to compare the change in LogMAR best-corrected visual acuity (BCVA) in patients before and after HBOT.

Results: There was no statistical difference among the three groups in patient demographic and clinical characteristics (vascular risk factors). In the HBOT group, patients who received an entire course of HBOT (twice a day for five days) revealed significant visual improvement at discharge evaluation with LogMAR BCVA compared to the partial HBOT and the control group (Table 1). Only one patient developed an episode of seizure while receiving HBOT; no complications occurred in the rest of the patients.

Conclusions: HBOT improves visual outcomes in CRAO patients who receive a full course of therapy. The benefit from HBOT does not appear to improve the visual outcome of patients who receive partial HBOT or no treatment. Our result suggests that HBOT is safe and should be offered to CRAO patients who present to the hospital within 24 hours of symptom onset as part of the standard of care. A large-scale prospective study is surely needed to validate our retrospective result.