Degeneration of retinal layers in multiple sclerosis subtypes quantified by optical coherence tomography

TLDR: The findings indicate a primary retinal pathology involving the inner nuclear layer in primary progressive MS, and suggest possible subclinical episodes of optic neuritis or retrograde trans-synaptic degeneration of retinal ganglion cells and their axons.

Abstract: Background:Optical coherence tomography can be used to assess retinal degeneration in multiple sclerosis (MS). Thinning of the retinal nerve fibre layer and macular thickness have been well characterized, but newer devices allow quantification of all retinal layers.Objectives:The objective of this study was to evaluate the thickness of the paramacular retina, peripapillary retinal nerve fibre layer, and deeper paramacular layers in MS patient subgroups, using state-of-the-art optical coherence tomography.Methods:Using a Heidelberg Engineering Spectralis device, we performed paramacular volumetric retinal scans and circular peripapillary fibre-layer scans, manually segmenting different retinal layers into single horizontal foveal scans in 95 patients with definite MS (42 relapsing–remitting, 41 secondary progressive, 12 primary progressive), plus 91 age- and sex-matched controls.Results:Even without a history of optic neuritis, all MS subgroups had significant thinning of the peripapillary retinal nerve fi...