To report the therapeutic efficacy of plasma exchange therapy on steroid-unresponsive neuromyelitisoptica (NMO) patients.

Three patients who had not achieved improvement of visual acuity and visual field after high steroid pulse therapy after optic neuritis visited our clinic with decreasing visual acuity combined with eye pain in the other eye. All patients were diagnosed as neuromyelitisoptica (NMO) based on the presence of NMO-IgG antibody and optic nerve enhancing in contrast-enhanced orbital magnetic resonance imaging (MRI). Recurrent optic neuritis was observed. Steroid pulse retreatment was started but visual acuity was not improved in all patients. The patients received plasma exchange therapy, followed by immune suppression therapy. All patients showed improved visual acuity and restored visual field promptly without recurrence of neuromyelitisoptica.

In case of steroid-unresponsive neuromyelitisoptica, plasma exchange should be promptly considered as the treatment of choice.