Assessment of the pathways of the visual analyzer using diffuse tensor MRI and optical coherence tomography in patients with multiple sclerosis

Early diagnosis of ophthalmic manifestations of multiple sclerosis (MS) is quite complicated. The aim . To assess the degree of impairment of the pathways of the visual analyzer in patients with MS, taking into account the data of structural optical coherence tomography and magnetic resonance imaging. Material and methods . Four groups of patients were analyzed: three groups of MS patients with various changes in visual functions and a group of somatically healthy patients. Structural changes of the optic nerve were assessed according to OCT and magnetic resonance studies. Results . A decrease in the thickness of the nerve fiber layer was found in groups 2 and 3 in the lower temporal sector – to 29–44 μm, in the upper temporal sector – to 30–33 μm, in the lower nasal sectors – to 11–18 μm. The data of groups 1 and 4 were comparable (p = 0.22). MR tractography in groups 2 and 3 determined the MRI picture of rarefaction and signs of interruption of the pathways, respectively. MR spectroscopy at the level of the visual cortex revealed: a decrease in NAA/Cho in groups 2 and 3 by 13–23 % (the data of groups 1 and 4 were comparable); a decrease in NAA/Cr by 17 % in group 1, and by 23 % in groups 2 and 3, a decrease in Cho/Cr by 21 % in group 1, by 13.4 % – in group 2 and by 8 % – in group 3. At the level of visual radiance, a decrease was observed: NAA/Cho by 31.5 % – in group 1, by 39.5 % – in group 2 and by 50 % – in group 3; NAA/Cr by 21 % – in group 1, by 32–35 % – in groups 2 and 3, and an excess of Cho/Cr by an average of 22 % in all groups. Conclusion . The data obtained indicate degenerative changes in the pathways of the visual analyzer not only in MS patients with partial optic nerve atrophy, but also in patients with no complaints and clinically pronounced visual impairment.