Brain Morphometric Alterations Along the Visual Pathway in Nonarteritic Anterior Ischemic Optic Neuropathy: A Voxel-Based Morphometry Study

Purpose: To investigate brain morphometric changes in patients with non-arteritic anterior ischemic optic neuropathy (NAION) using voxel-based morphometry (VBM) and to explore their associations with structural and functional ophthalmic parameters. Methods: This retrospective, cross-sectional study included 15 patients with NAION and 15 healthy controls. All participants underwent high-resolution 3.0-Tesla brain magnetic resonance imaging. Whole-brain VBM was performed using the Computational Anatomy Toolbox (CAT12) implemented in Statistical Parametric Mapping (SPM12) to assess gray and white matter volume differences between groups. Ophthalmic evaluation included best-corrected visual acuity, visual field mean deviation, retinal nerve fiber layer thickness, and ganglion cell–inner plexiform layer thickness measured by optical coherence tomography. Correlation analyses were performed to evaluate the relationships between brain morphometric measures and ophthalmic parameters. Results: Compared with controls, patients with NAION showed significantly reduced gray matter volumes in the limbic lobe, cuneus, occipital lobe, temporal lobe, middle temporal gyrus, parietal lobe, and frontal lobe (all p < 0.001). Increased gray matter volumes were observed in the bilateral cerebellum, while increased white matter volumes were found in the right cerebellum and posterior cerebellar lobe (p < 0.001). No significant correlations were identified between brain morphometric measures and ophthalmic parameters, disease duration, or visual function (all p > 0.05). Conclusions: Patients with NAION exhibit brain morphometric differences involving visual pathway–related cortical regions and the cerebellum. These findings suggest that central nervous system involvement in NAION may extend beyond isolated optic nerve pathology.