Alterations in Peripapillary and Macular Vasculature Measured by Optical Coherence Tomography Angiography and Their Clinical Correlation in Patients with Optic Neuritis Due to Multiple Sclerosis

Abstract Background Multiple Sclerosis (MS) is thought to be an autoimmune demyelinating disorder in which neuroaxonal degeneration is the principal driver of disability. Microvascular abnormalities in the central nervous system (CNS) may contribute to or be a biomarker of the disease process. Global reduction in cerebral perfusion has been repeatedly illustrated in imaging studies of MS, which could simply be a sequela of neurodegeneration or could be mediated by concomitant inflammatory vasculopathy. Endothelial cell dysfunction, excessive platelet activation, evidence of oxidative stress, altered blood- brain barrier permeability, vascular occlusions within demyelinating lesions, and hypoxia-like tissue injury have all been reported in people with MS (PwMS). Optical Coherence Tomography Angiography (OCTA) enables visualization of the ocular microvasculature through non-invasive, high-resolution enface and depth-resolved imaging. Using OCTA, non-invasive in vivo studies of neurological disorders through the human eye have emerged for MS, Alzheimer’s disease (AD), and various optic neuropathies. Objective To document changes in the peripapillary vascular network and retinal vascular plexuses in patients with optic neuritis due to MS and compare it to healthy individuals. Methods 26 eyes of 26 patients with Optic Neuritis (ON) caused by MS and 26 eyes of 26 sex and age- matched healthy controls. We used OCT AngioVue Enhanced Microvascular Imaging System aiming to quantify and compare microvasculature changes in the macula and peripapillary region between these two groups. this Cross-Sectional Study which has been conducted on patients from Ain Shams university hospitals, after the approval of the research ethics committee in the Faculty of Medicine, Ain Shams University between March to October. All cases underwent a Complete ophthalmological examination. the examination included Visual acuity assessment and Best corrected visual acuity. Slit Lamp Biomicroscopy examination with fundus examination, with OCT angiography (RTVue XR OCT Avanti System: Optovue, Fremont, USA) was done on the patients with MS during the attack of ON and to the healthy group. Results In our study, we found a statistically significant decrease in the superficial and deep vessel density in the macular area in the patients with ON compared to the healthy controls. Superficial vessel density in the macular area in the healthy ones was 49.90±3.4 (range: 42.4-54.6) while in those with MS was 44.09±4.9 (range 34.0-55.2). Deep vessel density in the macular area in patients without MS was 51.71±6.8 (range 35.3-61.4) while in patients with MS was 45.51±5.7 (range 37.0-57.8). There were statistically significant differences between groups (P = 0.001). Conclusion There is a decrease in superficial and deep vessel density and Radial peripapillary vessel density in patients with ON caused by MS in comparison to healthy controls.