Jiang H, Gameiro GR, Liu Y, et al. - Among 80 patients with relapsing-remitting multiple sclerosis (RRMS) and 99 age- and gender-matched healthy controls (HC, researchers conducted this cross-sectional study to determine the volumetric vessel density (VVD) in the intraretinal layers and its associations with visual function and disability. Using optical coherence tomography angiography, the retinal microvascular network in the macular area was imaged in 123 eyes without a history of optic neuritis (MSNON) and 36 eyes with a history of ON (MSON). Compared with HC, the VVD of RVN and DVP in MSNON were significantly higher. Compared with MSNON and HC, the VVD of RVN, SVP, and DVP in MSON were significantly higher. The VVD was positively related to EDSS and duration of the disease in both RVN and SVP but negatively related to the low contrast letter acuity. In addition, the VVD measurements were negatively and strongly linked to the corresponding tissue volumes. This is the first study showing increased retinal VVD in RRMS patients. Findings suggested that VVD measurements in the RVN and SVP were associated with disability and visual function, which can be developed as image markers to track the progression of the disease.