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Updated: Oct 18, 2026
Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients
Published on: April 14, 2014
Transorbital sonography reveals retrobulbar optic nerve neuroaxonal changes in multiple sclerosis
N Merli1, C Ferri2, M Copetti3
1University of Ferrara, Dept. of Neuroscience and Rehabilitation; Ferrara, Italy.
Background:
The optic nerve (ON), as an extension of the central nervous system, reflects multiple sclerosis (MS) pathological processes. Transorbital sonography (TOS) is emerging as a novel technique to detect ON changes. Our aim was to investigate retrobulbar ON morphometric changes in MS and their relationship with prior history of optic neuritis.
Methods:
122 MS subjects were enrolled, 68 with and 54 without history of optic neuritis. ON diameters without and with sheath were measured at 3 mm (OND3 and ONSD3) and 5 mm (ONSD5) posterior to the optic disc; myelination index (MI=ONSD3/ONSD5) was calculated. To account for intrasubject dependencies, linear mixed models (LMMs) for repeated measures were employed, adjusting for age at onset and body mass index.
Results:
ONs with history of inflammation (I-ON) exhibited significantly reduced diameters versus companion nerves in both measurements with and without sheath (OND3: p = 0.002; ONSD3: p = 0.010; ONSD5: p = 0.046). All ONs diameters progressively decreased with increasing neuritis frequency, demonstrating a dose-response effect. Significant measurement reductions in OND and ONSD3 were observed in I-ON of patients with Expanded Disability Status Scale >3, whereas no significant differences emerged for progression index (PI) > 0.20 among ONs with and without history of optic neuritis.
Conclusions:
TOS reliably captures ON morphometric changes related to inflammatory history and chronic neuroaxonal injury in MS, supporting its role as a promising biomarker of disability burden and progression independent of relapse activity (PIRA).
