Efficacy and Safety of Plasma Exchange and Immunoadsorption for Acute Optic Neuritis in Patients with Demyelinating Diseases: A Systematic Review and Meta-Analysis

Background: Optic neuritis (ON), a common manifestation of demyelinating disorders such as multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), often leads to significant visual impairment. Although high-dose corticosteroids are a first-line therapy, many patients experience incomplete recovery. Apheresis therapies, including plasma exchange (PLEX) and immunoadsorption (IA), are being increasingly used as rescue treatments, but their efficacy and safety are debated. Methods: We conducted a systematic review and meta-analysis of studies evaluating PLEX and IA for acute ON in patients with demyelinating diseases. Four databases were searched up to January 2025. The included studies reported visual or neurological outcomes in patients with MS, NMOSD, MOGAD, or idiopathic ON. The primary outcomes were treatment response and visual acuity changes (logMAR). The study quality was assessed using RoB 2, ROBINS-I, or JBI tools. Random effects models were employed for the meta-analysis. Results: Twelve studies (800+ ON attacks) were analyzed. Both PLEX and IA demonstrated significant visual improvement, with a pooled mean logMAR reduction of -1.11 (95% CI: -1.70 to -0.53). Early intervention correlated with better outcomes. MOGAD-ON patients showed the highest response rates, while delayed treatment in NMOSD-ON patients was linked to poorer vision. Adverse events were rare and mild. Conclusion: PLEX and IA are effective and safe second-line therapies for steroid-refractory ON, particularly when initiated early. These findings support the prompt use of apheresis in eligible patients to optimize visual recovery.