Retinal small vessel pathology is associated with disease burden in multiple sclerosis

Background: Alterations of the superficial retinal vasculature are commonly observed in multiple sclerosis (MS) and can be visualized through optical coherence tomography angiography (OCTA). Objectives: This study aimed to examine changes in the retinal vasculature during MS and to integrate findings into current concepts of the underlying pathology. Methods: In this cross-sectional study, including 259 relapsing–remitting MS patients and 78 healthy controls, we analyzed OCTAs using deep-learning-based segmentation algorithm tools. Results: We identified a loss of small-sized vessels (diameter < 10 µm) in the superficial vascular complex in all MS eyes, irrespective of their optic neuritis (ON) history. This alteration was associated with MS disease burden and appears independent of retinal ganglion cell loss. In contrast, an observed reduction of medium-sized vessels (diameter 10–20 µm) was specific to eyes with a history of ON and was closely linked to ganglion cell atrophy. Conclusion: These findings suggest distinct atrophy patterns in retinal vessels in patients with MS. Further studies are necessary to investigate retinal vessel alterations and their underlying pathology in MS.