Neuromyelitis optica spectrum disorder: Disease course and long-term visual outcome

Background: Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease that classically manifests as attacks of optic neuritis (ON) and transverse myelitis (TM). The prevalence, course, and severity of NMOSD vary considerably. Few studies report the neuroophthalmologic disease course and visual outcome. Objective: We sought to describe the course and long-term visual outcome in a cohort of NMOSD patients treated in a single tertiary referral center. Methods: The database was searched for all patients with NMOSD who were treated in our center from 2005 to 2014. Data collected included detailed visual outcome, grade of final visual disability, neuroimaging, and results of optical coherence tomography. Details on relapses, acute episodes, and maintenance therapies were recorded. Results: Of the 12 patients with NMOSD who were followed for a mean duration of 9.06 years, 10 (83%) were women. Mean age at presentation was 33.90 ± 16.94 years. Patients with acute attacks were treated with high-dose intravenous methylprednisolone and offered immunosuppressive maintenance. ON occurred in 18 eyes of 12 patients, with a cumulative total of 37 ON episodes. At the end of the follow-up period, no patient had become legally blind and only 1 patient had lost her driver's license. Pain associated with acute ON was common (83%), whereas optic disc edema was a rare finding in our patient cohort (6%). Conclusions: In this retrospective series of 12 patients with NMOSD, followed for a mean of 9.06 years, acute-phase treatment was given within 8 days of relapse, followed by maintenance therapy. Functional visual outcome, as measured by the World Health Organization/International Classification of Diseases, Tenth Revision visual disability scale was better than reported in previous studies and driver's license was preserved in 11 of 12 patients. Pain accompanied 83% of ON attacks and may not aid differentiating multiple sclerosis from NMOSD-related ON.