Retinal damage and vision loss in African American multiple sclerosis patients.

OBJECTIVE: To determine whether African American (AA) multiple sclerosis (MS) patients exhibit more retinal damage and visual impairment compared to Caucasian American (CA) MS patients.
METHODS: A total of 687 MS patients (81 AAs) and 110 healthy control (HC) subjects (14 AAs) were recruited at 3 academic hospitals between 2008 and 2012. Using mixed effects regression models, we compared high- and low-contrast visual acuity (HCVA and LCVA) and high-definition spectral domain optical coherence tomography measures of retinal architecture between MS patients of self-identified AA and CA ancestry.
RESULTS: In HCs, baseline peripapillary retinal nerve fiber layer (RNFL) thickness was 6.1µm greater in AAs (p = 0.047), whereas ganglion cell/inner plexiform layer (GCIP) thickness did not differ by race. In MS patients, baseline RNFL did not differ by race, and GCIP was 3.98µm thinner in AAs (p = 0.004). AAs had faster RNFL and GCIP thinning rates compared to CAs (p = 0.004 and p = 0.046, respectively). AA MS patients had lower baseline HCVA (p = 0.02) and worse LCVA per year of disease duration (p = 0.039). Among patients with an acute optic neuritis (AON) history, AAs had greater loss of HCVA than CA patients (p = 0.012).
INTERPRETATION: This multicenter investigation provides objective evidence that AA MS patients exhibit accelerated retinal damage compared to CA MS patients. Self-identified AA ancestry is associated with worse MS-related visual disability, particularly in the context of an AON history, suggesting a more aggressive inflammatory disease course among AA MS patients or a subpopulation therein.