Association of epiretinal membranes with disability in people with multiple sclerosis.

BACKGROUND

Epiretinal membranes (ERMs) consist of glial and fibrocellular tissue, potentially arising from pathologic microgliosis, macrogliosis, and/or retinal pigment epithelium (RPE) cell migration. The clinical relevance of ERMs in people with multiple sclerosis (PwMS) remains largely unstudied.

OBJECTIVES

To investigate ERM prevalence and their associations with retinal layer thicknesses and disability measures in PwMS.

METHODS

PwMS exhibiting ERMs (ERM+) were matched 1:1 with PwMS without ERMs (ERM-) by optic neuritis (ON) history, multiple sclerosis (MS) subtype, age, sex, and race. Disability assessments included high-contrast/low-contrast letter acuity (HC-/LCLA), Expanded Disability Status Scale (EDSS), walking speed test (WST), manual dexterity test (MDT), and processing speed test (PST) scores.

RESULTS

Among 1264 participants screened (1120 PwMS and 144 healthy controls [HCs]), ERMs were observed in 206 PwMS (18.4%) and 17 HCs (11.8%). ERM+ PwMS exhibited higher EDSS (1.0 ± 0.3, p = 0.002), longer WST (0.8 ± 0.2 seconds, p < 0.001), longer MDT (2.2 ± 0.5 seconds, p < 0.001), lower PST (-3.0 ± 1.4, p = 0.08), lower LCLA (-4.2 ± 1.1 letters, p < 0.001), and lower ganglion cell-inner plexiform layer (-1.8 ± 0.8 µm, p = 0.03), inner nuclear layer (-0.8 ± 0.3 µm, p = 0.01), outer nuclear layer (-1.6 ± 0.6 µm, p = 0.01), and RPE (-0.5 ± 0.1 µm, p < 0.001) thicknesses. Higher ERM stage correlated with greater disability.

CONCLUSION

ERMs may identify a distinct MS phenotype, potentially characterized by pathological microglial and/or macroglial activity. ERMs may be a marker of similar global processes throughout the central nervous system that potentially contribute to greater overall disability.