Bidirectional degeneration in the visual pathway in neuromyelitis optica spectrum disorder (NMOSD)

Objective:This study aims to investigate whether bidirectional degeneration occurs within the visual pathway and, if so, the extent of such changes in neuromyelitis optica spectrum disorder (NMOSD).Methods:In total, 36 NMOSD and 24 healthy controls (HCs) were enrolled. Three-dimensional T1-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging were used to analyze damage to the posterior visual pathway. Damage to the anterior visual pathway was measured by optical coherence tomography.Results:In total, 24 NMOSD with prior optic neuritis (NMOON) patients showed significant reduction of peripapillary retinal nerve fiber layer, inner and outer retinal thickness, lateral geniculate nucleus volume, primary visual cortex volume, and decreased integrity of optic radiations, compared with 12 NMOSD without prior optic neuritis (NMONON) patients and 24 HCs. In NMONON, only the inner retinal thickness and the integrity of optic radiations were significantly reduced in comparison with HCs. Moreover, p...