Description

ABSTRACT

Background/Aims: To determine the effect of the timing of hyperbaric oxygen (HBO2) therapy on functional and structural outcomes in central retinal artery occlusion (CRAO).

Methods: This single‑center retrospective cohort study analyzed 101 eyes with CRAO treated with HBO2. Eyes were stratified by symptom‑to‑treatment interval: ≤12 hours (Group 1), 12–24 hours (Group 2), 24–36 hours (Group 3), and >36 hours (Group 4). Best‑corrected visual acuity (BCVA-logMAR), central macular thickness (CMT), and inner retinal hyperreflective band thickness (IRHBT) were recorded at presentation, week 1, and month 6. 

Results: Presentation BCVA was 2.16 ± 1.04, improving to 1.77 ± 1.02 at month 6 (p = 0.03). The mean BCVA gain was greatest in Group 1: −0.85 ± 0.96, and declined markedly with delayed treatment initiation (Group 2: −0.48 ± 1.38; Group 3: −0.10 ± 1.50; Group 4: −0.08 ± 1.77). The mean BCVA improved significantly from 2.04 ± 0.78 at presentation to 1.19 ± 0.56 at the 6-month follow-up (p = 0.02). Early treatment was also associated with more pronounced reductions in CMT and IRHBT, whereas anatomical changes were negligible when therapy was initiated beyond 24 hours. Baseline CMT and IRHBT showed modest but significant correlations with final BCVA (r = 0.37, p = 0.03 , and r=0.34, p=0.04, respectively).

Conclusion: HBO2 provides a significant, time-sensitive benefit for CRAO; initiating therapy within 12–24 hours maximizes recovery and retinal remodeling, validating HBO2 as a critical adjunct and necessitating rapid triage in ophthalmic emergencies.

Keywords: Central retinal artery occlusion, hyperbaric oxygen therapy, inner hyperreflective band, optical coherence tomography.