Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing disease predominately affecting the optic nerves and spinal cord. Patients with NMOSD may experience visual and neurological deficits that can lead to blindness and paralysis. However, little is reported about the cumulative impact of relapses on visual acuity and recovery.
A retrospective, observational cohort analysis was conducted to assess the impact of relapses on visual acuity and neurological disability in patients with anti-aquaporin-4 immunoglobulin G-positive (AQP4+) NMOSD.
Patients with AQP4+ NMOSD in the University of Utah healthcare system were identified. Electronic data (health status, physician notes, AQP4+ status, NMOSD diagnosis, and other key patient data) were extracted from the Enterprise Data Warehouse and confirmed via medical chart reviews.
The analysis included 47 patients with AQP4+ NMOSD (mean age at diagnosis: 46 years; female: 75%, white: 70%; median [minimum, maximum] follow-up time: 3.6 [0.0, 11.4] years). At enrollment, 25 patients (53%) had optic neuritis, 15 (32%) had transverse myelitis, and 7 (15%) had a mixed or unknown presentation. Of the 47 patients, 14 experienced a total of 26 relapses, and 33 did not relapse.
Baseline visual acuity was assessed in a subset of symptomatic patients. Data were available for 9 relapsing and 23 nonrelapsing patients. At baseline, 28% of patients had bad eyesight (20/150-no light perception). From baseline to last follow-up, the proportion of patients with bad eyesight increased from 21% to 29% in relapsing patients and decreased from 30% to 24% in nonrelapsing patients.
Neurological disability was assessed via the modified Rankin Scale (mRS). Pre-enrollment mean (standard deviation [SD]) mRS values were similar in relapsing (1.50 [1.22]) and nonrelapsing patients (1.42 [1.39]). At the last visit, the mean (SD) mRS value in relapsing patients was 3.43 (1.79), which was 1.49-fold higher than the mean mRS value in nonrelapsing patients.
In this cohort of patients with AQP4+ NMOSD, the proportion of relapsing patients with bad eyesight increased over time, but the proportion of nonrelapsing patients with bad eyesight decreased. Per the mRS, relapsing patients also experienced increased neurological disability when compared with nonrelapsing patients. Treatment strategies that reduce the risk of relapse should be considered to prevent progression of these deficits in patients with NMOSD.