Summary of the main studies assessing HBOT for treating retinal artery occlusion
| Study, year | Current study, 2021 | Beiran et al, 200114 | Weinberger et al, 200215 | Menzel-Severin et al, 201216 | Hadanny et al, 20167 | Elder et al, 201717 | Wu et al, 201819 |
| Study design | Prosp. Non-Comp. | Retrosp. Comp. | Prosp. Non-Comp. | Retrosp. Comp. | Restrosp. Non-Comp. | Restrosp. Non-Comp. | Meta-analysis |
| Treatment | HBOT | HBOT vs Observ. | HBOT+HD | HBOT+HD vs. HD | HBOT | HBOT | HBOT |
| No of patients | 31 | 72 | 21 | 80 | 128 | 31 | 251 |
| Inclusion criteria | CRAO+BRAO for <7 days | CRAO+BRAO for <8 hours | CRAO for <12 hours | CRAO for<12 hour with BCVA<+1 logMAR | CRAO for<20 hour with BCVA<0.5 logMAR | CRAO+BRAO | CRAO+BRAO |
| Mean age (years) | 68.3 | 69.5 vs 56 | NR | 69 vs 74 | 66.4 | 70 | NR |
| Mean initial BCVA (logMAR) | +1.51 | +1 vs. +1.1 | +2.3 to +1.1 | +1.8 vs +1.7 | +2.14 | +2.3 to +0.2 | NR |
| Mean final BCVA (logMAR) | +1.1 | +0.5 vs. +0.9 | NR | +1.5 vs +1.6 | +1.62 | +2.6 to −0.1 | NR |
| Success criteria | Improv. ≥0.3 logMAR | Improv. ≥3 Snellen lines | Subjective visual improv. | Improv. ≥3 Snellen lines | Improv. ≥0.3 logMAR | NR | NR |
| Visual improv. according to the success criterion (%) | 48.4 | 82.9 vs 29.7 p=0.000 | 90.5 | 38.8 vs 17.9 p=0.06 | 67.2 | 29 | ten to 90 OR 5.61 (3.6–8.73) |
| Good prognosis factors | Antiplatelets on referral | High blood pressure | NR | Aspirin | No cherry red spot | Time to treatment | Duration of HBOT |
| Mean no of HBOT sessions | 34 | NR | NR | 5 | 4 | 4 | NR |
| HBOT-related adverse events (%) | Barotrauma (19.4) Hypertension during the session (29.0) | NR | NR | None | Barotrauma (2.3) Otalgia (1.5) Epistaxis (0.7) Dyspnoea (0.7) | Claustrophobia, barotrauma, acute upper respiratory tract infection | NR |
BRAO, branch retinal artery occlusion; Comp, comparative; CRAO, central retinal artery occlusion; HBOT, hyperbaric oxygen therapy; HD, haemodilution; logMAR, Logarithm of the Minimum Angle of Resolution; NR, not reported; Observ, observation; Prosp, prospective; RAO, retinal artery occlusion; Retrosp, retrospective; VA, visual acuity.