Neuroaxonal loss is a key factor in the pathophysiology of multiple sclerosis (MS), closely linked to clinical disability. However, monitoring neuroaxonal loss directly in vivo remains difficult.

Optical coherence tomography (OCT) provides a non-invasive and patient-friendly method to visualize and measure the layers of neurons and axons in the retina, with high consistency in results across different raters and repeat assessments. OCT changes are commonly observed in patients with MS (PwMS), resulting from clinically apparent or subclinical optic nerve demyelination, retrograde degeneration due to damage in the posterior visual pathway, and primary degeneration of ganglion cells, which occurs alongside neuronal degeneration in other parts of the central nervous system.

Selected scientific publications

From: Damage of the lateral geniculate nucleus in MS: Assessing the missing node of the visual pathway.

Assessment of the lateral geniculate nucleus (LGN) and the other nodes of the visual pathway. The LGN is the central node of the visual pathway, receiving input from retinal ganglion cells and sending axons to the primary visual cortex. To study structural damage and its relation to anterograde and retrograde degeneration, several visual pathway nodes were assessed. (A) Retinal ganglion cell integrity was evaluated using optical coherence tomography (OCT), with the mean ganglion cell-inner plexiform layer (GC-IPL) thickness measured. (B) LGN volume was measured using 3D MPRAGE T1-weighted MRI and the MAGeT Brain algorithm, with the LGN segmented in red and the medial geniculate nucleus in green as a control. (C, D) Damage to the optic radiations (OR) was assessed with diffusion-weighted MRI, including the mean fractional anisotropy (FA) and OR lesion volume. The schematic figure of the afferent visual system (on the left) is adapted from the website of the Neurodiagnostics Laboratory @ Charité-Universitätsmedizin Berlin, Germany (neurodial.de/2017/08/25/schematic-figure-the-afferent-visual-system-creative-commons-license). read

From Optical coherence tomography versus other biomarkers: Associations with physical and cognitive disability in multiple sclerosis.

Correlations between OCT measures of neuroaxonal loss and measures of disability. Scatter plots showing the correlation analysis between OCT (pRNFL and GCIPL: mean of both eyes, with exclusion of ON-eyes) and disability measures (SDMT and EDSS). (a) Correlation between GCIPL volume and SDMT. (b) Correlation between pRNFL thickness and SDMT. (c) Correlation between GCIPL volume and EDSS (log10). (d) Correlation between pRNFL thickness and EDSS (log10). read