Efficacy of Plasma Exchange Treatment for Demyelinating Optic Neuritis Associated with Various Serum Antibodies: A Prospective Cohort Study

To evaluate the value of plasma exchange (PE) for patients with three subtypes of demyelinating optic neuritis (ON): aquaporin-4 (AQP4) antibody-positive ON (AQP4-ON), myelin oligodendrocyte glycoprotein (MOG) antibody-positive ON (MOG-ON), and AQP4 and MOG double-antibody-seronegative ON (D-ON).A single-center prospective study compared the logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) at most severe onset, 1 day before intravenous high-dose methylprednisolone (IVMP) treatment, 1 day before PE treatment, after five-cycles of PE therapy, and at 1-, 3-, and 6-month follow-up visits. The proportions of eyes in each visual outcome category were also compared. Logistic regression and a receiver operating characteristic curve were used to analyze predicted factors for VA improvement.A total of 124 ON attacks of 122 patients were included. No significant differences were found in BCVA (P = 0.659) before and after PE therapy for 22 D-ON attacks, but VA improved in two of six MOG-ON patients. In 95 AQP4-ON patients suffering 96 attacks, the mean logMAR BCVA markedly improved and was steadily maintained after five-cycles of PE treatments (adjusted P < 0.001), with VA exhibiting a significantly increasing trend (adjusted P = 0.001) after PE treatment. The combination of the number of previous ON episodes and the time window to PE treatment showed accuracy of 74.7% for predicting an improvement in BCVA score ≥ 2 levels. In addition, a combination of logMAR VA before PE and the time window to PE treatment resulted in 83.4% accuracy in predicting whether VA would regain 1.0 logMAR.PE therapy effectively improves visual outcomes for AQP4-ON patients, but offers limited value for D-ON patients. Early initiation greatly increases likelihood of achieving VA improvement.