Identifying Microvascular Differences in Multiple Sclerosis via Optical Coherence Tomography Angiography (OCT-A)

Abstract

Purpose : Multiple sclerosis (MS), an autoimmune disease of the central nervous system, is associated with numerous vision complications (i.e. blurred vision, diplopia, optic neuritis, and occasional blindness). We aim to identify microvascular differences in a cohort of MS patients through quantitative analysis of OCT-A images.

Methods : This retrospective observational study utilizes a MS patient cohort of 21 patients. Patients received a dilated exam to check for pre-existing retinal disease, followed by capturing OCT-A imaging and HD-OCT macular and optic nerve scans. A cohort of 17 healthy controls was used for comparison. Images from the superficial and deep layers were separated into 11 macular regions. Quantitative analysis using MATLAB was completed to evaluate parameters of vessel density and intensity. Patients will be stratified by MS severity using the Expanded Disability Status Scale (EDSS) and their history of optic neuritis to determine whether microvascular changes correlate with MS severity. Non-parametric and parametric statistical analyses will be completed for normality and significance.

Results : Preliminary data from 21 MS patients’ OCT-A images showed a decrease in macular vessel density and intensity compared to 17 healthy controls’ images. In the superficial layer, MS patients had lower average vessel densities and intensities in 7 out of 11 (63.6%) and 8 out of 11 (72.7%) macular regions, respectively. In the deep layer, MS patients had lower average vessel densities and intensities in 6 out of 11 (54.5%) and 7 out of 11 (63.6%) macular regions, respectively. The optic nerve scans of the MS patient cohort will be compared with a healthy control group. Further nonparametric and parametric statistical analyses will be run on the collected data.

Conclusions : Curated OCT-A and macular vessel density data suggests microvascular differences in MS patient groups compared to healthy controls. This is indicative of a potential relationship between ophthalmic microvascular changes and MS severity. Further statistical analysis will help to highlight the significance of these early findings. Preliminary data further suggests that specific regions of the macula may be particularly affected by MS. Future research investigating microvascular biomarkers on OCT-A imaging may enable ophthalmologists and neurologists to better care for MS patients and preserve eye function.

This is a 2020 ARVO Annual Meeting abstract.