Abstract DP304: Hyperbaric Oxygen Therapy Predicts Early Visual Improvement for Acute Retinal Ischemia

Central Retinal Artery Occlusion (CRAO) is a recognized form of ischemic stroke requiring emergent medical evaluation. Guidelines suggest intravenous thrombolysis (IVT) and hyperbaric oxygen therapy (HBOT) can be effective treatment strategies, though randomized controlled trial data are lacking. We investigated clinical data and treatment interventions associated with early visual improvement using a large single-institution registry of patients evaluated for acute monocular vision loss. A multicenter retrospective data registry was constructed for patients evaluated within a metropolitan area for monocular vision loss between 2021-2024. Clinical, diagnostic, and treatment characteristics were recorded as well as visual outcomes. Patients who received consensus diagnosis of CRAO or branch retinal artery occlusion (BRAO) were included in this analysis. Visual improvement was categorized binomially according to patient-reported improvement or measurable increase in visual acuity documented at hospital discharge. Binomial logistic regression models were constructed to evaluate the predictive value of treatment intervention (IVT, HBOT) and clinical variables (NIHSS, ESR, CRP) on visual outcomes. Test of association for treatment strategy and early visual improvement were performed by Chi-square test. A total of 73 patients were included in the analysis, of which, the median age was 68 (IQR 60-74) and 38 (52.1%) were female (Table 1). CRAO and BRAO patients were 60 and 13 respectively. Median time from last known well to medical evaluation was 15.7 hours with HBOT treated (11.8 h) and CRAO patients (12.7 h) having similar times. Among 20 interventions (5 IVT, 15 HBOT), 14.8% showed early visual improvement versus 8.1% with conservative management. A binomial model using treatment intervention and NIHSS were predictive of early visual improvement with specificity 97.9% but 53.8% sensitivity. HBOT showed greatest contribution. Combination of treatment intervention, ESR, CRP, and NIHSS in a binomial logistic regression demonstrated 84.6% specificity, 88.9% sensitivity, and 0.966 AUC. HBOT was significantly associated with early visual improvement (p < 0.001), whereas IVT demonstrated trend toward improvement (p = 0.078) (Table 2). Hyperbaric oxygen therapy was associated with early visual improvement alone and predictive of early visual improvement when combined with other treatments and clinical variables in patients with CRAO/BRAO.