Retinal and Choriocapillary Vascular Changes in Early Stages of Multiple Sclerosis: A Prospective Study.

Optical Coherence Tomography Angiography (OCTA) abnormalities occur in multiple sclerosis (MS) over the course of the disease. OCTA investigations at early MS stages are lacking. We aimed to investigate vessel density in macular and papillary regions over two years after an initial demyelinating event (IDE). Vessel density was analyzed in superficial, deep, choriocapillaris and radial peripapillary plexus at baseline, and after one and two years. We also evaluated structural OCT parameter changes of the ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL). We evaluated 30 eyes from 15 IDE patients (7 females, 8 males, mean age 28.4 ± 9.6 years) and 30 eyes from 15 healthy controls. After 2 years, we reported in the IDE group a reduced vessel density in the superficial capillary plexus, deep capillary plexus and radial peripapillary capillary plexus with respect to the baseline (coeff. β = -2.779, p = 0.013; coeff. β = -4.055, p = 0.018 and coeff. β = -2.687, p ≤ 0.001; respectively), while GCC and RNFL thicknesses did not change. Vessel density reduction was not associated with an expanded disability status scale (EDSS) change, relapse occurrence or magnetic resonance imaging activity. The analysis of healthy controls did not reveal any impairment in OCT and OCTA parameters over 2 years of follow-up. Retinal vascular loss occurs in patients with an IDE independently from clinical and radiological disease activity. Retinal vessel density could represent a novel early biomarker to monitor the MS pathological burden.