Abstract
BACKGROUND: The relationship between coronavirus disease 2019 (COVID-19) and optic neuritis (ON) remains unclear, with limited evidence on its clinical features and outcomes. This study aimed to investigate the impact of COVID-19 on ON subtypes and prognosis. METHODS: We conducted a single-centre retrospective cohort study, comparing acute ON patients with and without recent COVID-19 infection during the omicron wave (December 2022 to January 2023). A historical control group from the pre-COVID-19 era was included for comparison. RESULTS: A total of 55 ON patients were included, of whom 12 had recent COVID-19 infection. COVID-19-associated ON showed a higher incidence of acute disseminated encephalomyelitis-associated ON (ADEM-ON, 25% vs. 0%) and a lower rate of aquaporin-4 antibody-associated ON (AQP4-ON, 0% vs. 31.4%). These patients presented more frequently with eye pain (75%) and respiratory symptoms (60%). At onset, 66.7% experienced severe visual loss (mean logMAR 1.10 ± 0.71), but most (83.3%) achieved good visual recovery (mean logMAR 0.08 ± 0.44) after immunotherapy. Only one relapse was observed during follow-up. CONCLUSIONS: COVID-19 may trigger distinct autoimmune processes in ON, particularly increasing ADEM-ON prevalence. Despite initial severe vision loss, outcomes are generally favourable with timely treatment. These findings expand understanding of neuro-ophthalmic complications related to COVID-19.