Methodology :
Patients diagnosed CRAO with symptom (acute blindness) onset ≤6hours, who failed emergency bedside ocular treatments, would be recruited for a course of HBOT situated in a tertiary hospital receiving territory-wide CRAO referrals from both public and private practitioners 24 hours everyday. Patients' demographics, onset-to-door/HBOT time, diseased eye characteristics, medical and drug history were all collected prospectively. Treatment outcomes were reviewed in June 2020 for the 18-month service period. Statistical analyses were done by SPSS for Wilcoxon, Fisher’s exact and Spearman's correlation tests.
Result & Outcome :
26 patients aged 67.5±13.3 years old (44–89) were included, with male-to-female ratio of 1.6:1. Mean follow up period was 10.0±5.3 months, and mean visual acuity (VA) improvement was 0.48±0.57 logarithm of minimal angle of resolution (Z=-3.67, p=0.000). Age, pre-HBOT VA, usage of anti-platelet/anti-coagulant, onset-to-door time and onset-to-HBOT time were not correlated (p=0.49,0.42,0.42,0.36,0.42) with VA outcomes. Concerning optical coherence tomography (OCT) parameters, 1mm-zone of central macular thickness (CMT) was not associated with VA changes (p=0.119), but the circular rim of 1-to-3mm-zone of CMT was fairly associated (Spearman's coefficient 0.45, p=0.02). Fundus fluorescein angiography’s (FFA) complete retinal perfusion time was moderately associated with visual outcome (Spearman's coefficient 0.58, p=0.01). One patient got concomitant stroke with CRAO, otherwise no further ischemic cerebro-cardiovascular events, nor contralateral eye CRAO happened during the follow-up period.
HBOT is promising to CRAO patients to regain vision for navigation. Thinner 1-to-3mm-zone CMT, but not the central 1mm zone, was associated with better visual outcome. OCT alone, without the invasive FFA, may be used for future triage of cases for HBOT.
