Plasma exchange: an effective add-on treatment of optic neuritis in neuromyelitis optica spectrum disorders

Purpose To evaluate the efficiency of plasma exchange (PE) add-on on optic neuritis (ON) in neuromyelitis optica spectrum disorders (NMOSD). Methods Our ambispective, nonrandomized study was performed in Southwest Hospital, Southwest Eye Hospital, Army Medical University. We studied 31 consecutive NMOSD patients characterized by ON and hospitalized from September 2015 to May 2018. Their clinical features were assessed, and efficiency of PE add-on treatment in ON of NMOSD was evaluated. Correlation was assessed between the effect of steroid pulse therapy (SPT) and the number of ON episodes in NMOSD. Results All 31 NMOSD patients accepted SPT; 15 patients of them accepted SPT and PE add-on. In these 15 patients, after PE add-on treatment, the patients' visual acuity was further significantly improved (P = 0.000, N = 23), including 3 no light perception (NLP) patients. After the treatment, the visual function recovered quickly in the first 2 months and then gradually slowed down; the visual function remained stable about 6 months later. The correlation coefficient between visual acuity improvement of SPT and the number of ON episodes was - 0.311 (P = 0.030, N = 49). Conclusion One clinical feature of NMOSD can be repeated vision impairment. In NMOSD patients characterized by ON, efficacy of SPT is limited as the number of episodes increased, and PE add-on is more effective. Even though the visual acuity of NMOSD patients decreases to NLP during episodes, there is still a chance to restore vision by PE add-on treatment.