Long-Term Visual Prognosis in Patients With Aquaporin-4-Immunoglobulin G–Positive Neuromyelitis Optica Spectrum Disorder

BACKGROUND: To identify the factors associated with visual prognosis for functional and structural outcomes of optic neuritis (ON) in patients with aquaporin-4-immunoglobulin (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD). METHODS: We included the eyes that experienced at least 1 episode of ON and were followed for at least 2 years after the first attack of ON in patients with AQP4-IgG-positive NMOSD. We performed a retrospective review of clinical data, including ophthalmological examination and orbital MRI, of 34 eyes of 22 patients. Functional outcomes were measured as final visual acuity, visual field index, and mean deviation and structural outcomes as final retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness. RESULTS: The mean age at onset of the first ON was 42.7 ± 13.7, and all patients were female. The poor visual acuity was significantly associated with the worse final visual acuity and thinner RNFL and GCIPL. Older age also showed a negative correlation with RNFL thickness. The number of attacks was not statistically significant for functional and structural outcomes. The lesion involving the intracanalicular optic nerve to the chiasm on orbital MRI showed worse visual acuity and a thinner GCIPL. Rapid high-dose intravenous methylprednisolone pulse therapy within 3 days was statistically significant, with better visual acuity and more preserved GCIPL thickness. CONCLUSIONS: Our results indicate that the severity of ON rather than the number of recurrences might be critical for the visual prognosis of patients with AQP4-IgG-positive NMOSD. Rapid treatment within 3 days may improve visual outcomes, and a younger age at onset may have better visual outcomes.