Morphometric assessment of the corpus callosum and optic nerve using magnetic resonance imaging in patients with multiple sclerosis: a retrospective case–control study

Background Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system that frequently affects the optic nerve sheath (ONS) and the corpus callosum (CC). Routine magnetic resonance imaging (MRI) can demonstrate structural changes associated with disease, although the clinical significance of simple morphometric measurements remains uncertain. Objectives To compare corpus callosum dimensions and optic nerve sheath diameter (ONSD) between patients with multiple sclerosis and healthy controls and to assess their associations with age. Materials and methods This retrospective study included 196 patients (98 with MS and 98 healthy controls) aged 18–78 years. Midsagittal T2-weighted images were used to measure CC length, genu, body, and splenium thicknesses, and axial T1-weighted MR images were used to measure bilateral ON sheath diameter, and group comparisons, receiver operating characteristic (ROC) analysis, and age-related correlations were performed. Results Compared with healthy controls, patients with MS had significantly shorter CC lengths (7.04 ± 0.46 cm), splenium thicknesses (1.04 ± 0.19 cm), right ONSD (0.33 ± 0.06 cm), and left ONSD (0.33 ± 0.06 cm) ( p < 0.05). Among the measured parameters, genu and body thickness had the highest area under curve (AUC) values, although their discriminatory performance was limited. In the MS group, no significant correlations were observed between age and the measured CC dimensions or optic nerve sheath diameters. Conclusion Compared with healthy controls, patients with MS presented significant differences in CC length, splenium thickness, and bilateral ONSD. These MRI-derived morphometric differences may provide complementary information alongside established clinical and radiological findings, but their limited discriminatory performance does not support their use as standalone diagnostic biomarkers.