Background: The retinal vasculature may be altered in multiple sclerosis (MS), potentially acting as a biomarker of disease processes. Objective: To compare retinal vascular plexus densities in people with MS (PwMS) and healthy controls (HCs), and examine correlations with visual function and global disability. Methods: In this cross-sectional study, 111 PwMS (201 eyes) and 50 HCs (97 eyes) underwent optical coherence tomography angiography (OCTA). Macular superficial vascular plexus (SVP) and deep vascular plexus (DVP) densities were quantified, and poor quality images were excluded according to an artifact-rating protocol. Results: Mean SVP density was 24.1% (SD = 5.5) in MS eyes (26.0% (SD = 4.7) in non-optic neuritis (ON) eyes vs. 21.7% (SD = 5.5) in ON eyes, p < 0.001), as compared to 29.2% (SD = 3.3) in HC eyes ( p < 0.001 for all MS eyes and multiple sclerosis optic neuritis (MSON) eyes vs. HC eyes, p = 0.03 for MS non-ON eyes vs. HC eyes). DVP density did not differ between groups. In PwMS, lower SVP density was associated with higher levels of disability (expanded disability status scale (EDSS): R2 = 0.26, p = 0.004; multiple sclerosis functional composite (MSFC): R2 = 0.27, p = 0.03) and lower letter acuity scores (100% contrast: R2 = 0.29; 2.5% contrast: R2 = 0.40; 1.25% contrast: R2 = 0.31; p < 0.001 for all). Conclusions: Retinal SVP density measured by OCTA is reduced across MS eyes, and correlates with visual function, EDSS, and MSFC scores.

Background: Comparative studies of characteristics of optic neuritis (ON) associated with myelin oligodendrocyte glycoprotein-IgG (MOG-ON) and aquaporin-4-IgG (AQP4-ON) seropositivity are limited. Objective: To compare visual and optical coherence tomography (OCT) measures following AQP4-ON, MOG-ON, and multiple sclerosis associated ON (MS-ON). Methods: In this cross-sectional study, 48 AQP4-ON, 16 MOG-ON, 40 MS-ON, and 31 healthy control participants underwent monocular letter-acuity assessment and spectral-domain OCT. Eyes with a history of ON >3 months prior to evaluation were analyzed. Results: AQP4-ON eyes exhibited worse high-contrast letter acuity (HCLA) compared to MOG-ON (−22.3 ± 3.9 letters; p < 0.001) and MS-ON eyes (−21.7 ± 4.0 letters; p < 0.001). Macular ganglion cell + inner plexiform layer (GCIPL) thickness was lower, as compared to MS-ON, in AQP4-ON (−9.1 ± 2.0 µm; p < 0.001) and MOG-ON (−7.6 ± 2.2 µm; p = 0.001) eyes. Lower GCIPL thickness was associated with worse HCLA in AQP4-ON (−16.5 ± 1.5 letters per 10 µm decrease; p < 0.001) and MS-ON eyes (−8.5 ± 2.3 letters per 10 µm decrease; p < 0.001), but not in MOG-ON eyes (−5.2 ± 3.8 letters per 10 µm decrease; p = 0.17), and these relationships differed between the AQP4-ON and other ON groups ( p < 0.01 for interaction). Conclusion: AQP4-IgG seropositivity is associated with worse visual outcomes after ON compared with MOG-ON and MS-ON, even with similar severity of macular GCIPL thinning.

Objective:To evaluate whether a retinal spectral-domain optical coherence tomography (SD-OCT) assessment at baseline is associated with long-term disability worsening in people with multiple sclerosis (PwMS), we performed SD-OCT and Expanded Disability Status Scale (EDSS) assessments among 132 PwMS at baseline and at a median of 10 years later.Methods:In this prospective, longitudinal study, participants underwent SD-OCT, EDSS, and visual acuity (VA) assessments at baseline and at follow-up. Statistical analyses were performed using generalized linear regression models, adjusted for age, sex, race, MS subtype, and baseline disability. We defined clinically meaningful EDSS worsening as an increase of ≥2.0 if baseline EDSS score was <6.0, or an increase of ≥1.0 if baseline EDSS score was ≥6.0.Results:132 PwMS (mean age: 43 years; n=106 patients with relapsing remitting MS) were included in analyses. Median duration of follow-up was 10.4 years. In multivariable models excluding eyes with prior optic neuritis, relative to patients with an average baseline ganglion cell+inner plexiform layer (GCIPL) thickness ≥70µm (the mean GCIPL thickness of all eyes at baseline), an average baseline GCIPL thickness <70µm was associated with a 4-fold increased odds of meaningful EDSS worsening (adjusted odds ratio: 3.97; 95% CI: 1.24-12.70; p=0.02), and an almost 3-fold increased odds of low-contrast VA worsening (adjusted odds ratio: 2.93; 95% CI: 1.40-6.13; p=0.04).Conclusions:Lower baseline GCIPL thickness on SD-OCT is independently associated with long-term disability worsening in MS. Accordingly, SD-OCT at a single time-point may help to guide therapeutic decision making among individual PwMS.Classification of Evidence:This study provides Class I evidence that lower baseline GCIPL thickness on SD-OCT is independently associated with long-term disability worsening in MS.

Background: In people with multiple sclerosis (MS), optic neuritis (ON) results in inner retinal layer thinning, and reduced density of the retinal microvasculature.Objective: To compare inter-eye differences (IEDs) in macular optical coherence tomography (OCT) and OCT angiography (OCTA) measures in MS patients with a history of unilateral ON (MS ON) vs. MS patients with no history of ON (MS non-ON), and to assess how these measures correlate with visual function outcomes after ON.Methods: In this cross-sectional study, people with MS underwent OCT and OCTA. Superficial vascular plexus (SVP) density of each eye was quantified using a deep neural network. IEDs were calculated with respect to the ON eye in MS ON patients, and with respect to the right eye in MS non-ON patients. Statistical analyses used mixed-effect regression models accounting for intra-subject correlations.Results: We included 43 MS ON patients (with 92 discrete OCT/OCTA visits) and 14 MS non-ON patients (with 24 OCT/OCTA visits). Across the cohorts, mean IED in SVP density was −2.69% (SD 3.23) in MS ON patients, as compared to 0.17% (SD 2.39) in MS non-ON patients (p = 0.002). When the MS ON patients were further stratified according to time from ON and compared to MS non-ON patients with multiple cross-sectional analyses, we identified that IED in SVP density was significantly increased in MS ON patients at 1–3 years (p = &lt; 0.001) and &gt;3 years post-ON (p &lt; 0.001), but not at &lt;3 months (p = 0.21) or 3–12 months post-ON (p = 0.07), while IED in ganglion cell + inner plexiform layer (GCIPL) thickness was significantly increased in MS ON patients at all time points post-ON (p ≦ 0.01 for all). IED in SVP density and IED in GCIPL thickness demonstrated significant relationships with IEDs in 100% contrast, 2.5% contrast, and 1.25% contrast letter acuity in MS ON patients (p &lt; 0.001 for all).Conclusions: Our findings suggest that increased IED in SVP density can be detected after ON in MS using OCTA, and detectable changes in SVP density after ON may occur after changes in GCIPL thickness. IED in SVP density and IED in GCIPL thickness correlate well with visual function outcomes in MS ON patients.