Hyperbaric oxygen therapy for central retinal artery occlusion: experience in Hong Kong

Objective: To review medical records of patients who underwent hyperbaric oxygen therapy (HBOT) for central retinal artery occlusion (CRAO).Methods: Medical records of patients who underwent HBOT for CRAO between November 2018 and December 2019 were reviewed. The first emergency HBOT was at 2.8 atmosphere absolute for 90 minutes with staged decompression. Subsequent sessions were at 2.4 atmosphere absolute twice daily or daily. Patients were followed up daily at the eye clinic. HBOT lasted for 5 days or 10 treatment sessions if there was visual improvement on day 3. Treatments were discontinued if patients had no visual improvement or were unable to tolerate the treatment or experienced major adverse effects, or when the patient was confirmed to not have CRAO.Results: Of 31 patients who underwent HBOT, 25 with CRAO (17 men, 8 women; aged 44 to 89 years) were included. Mean onset-to-door time was 3.3±4.2 hours, and mean onset-to-HBOT time was 13.3±7.4 hours. Mean number of HBOT sessions was 7.9±2.7. Mean change in visual acuity (VA) was -0.43 LogMAR (p=0.003). At the end of treatment, 84% had VA of 0.1 (1.0 logMAR) or worse and 64% had VA of finger counting (1.7 logMAR) or worse. No factors were associated with VA improvement including age, onset-to-door time, onset-to-HBOT time, number of HBOT sessions, or pre-HBOT VA. Conclusion: HBOT for CRAO shows promising visual outcomes. It is important to be aware of the systemic complication of CRAO and provide timely systemic cardiovascular work up for CRAO patients.