Neuroprotective influence of macular xanthophylls and retinal integrity on cognitive function among persons with multiple sclerosis.

BACKGROUND:No studies to date have examined if macular xanthophyll accumulation and retinal integrity are independently associated with cognitive function in individuals with multiple sclerosis (MS). This study explored whether macular xanthophyll accumulation and structural morphometry in the retina were associated with behavioral performance and neuroelectric function during a computerized cognitive task among persons with MS and healthy controls (HCs). METHODS:42 HCs and 42 individuals with MS aged 18-64 years were enrolled. Macular pigment optical density (MPOD) was measured using heterochromatic flicker photometry. Optic disc retinal nerve fiber layer (odRNFL), macular retinal nerve fiber layer, and total macular volume were assessed via optical coherence tomography. Attentional inhibition was assessed using an Eriksen flanker task while underlying neuroelectric function was recorded using event-related potentials. RESULTS:Persons with MS had a slower reaction time, lower accuracy, and delayed P3 peak latency time during both congruent and incongruent trials compared with HCs. Within the MS group, MPOD explained variance in incongruent P3 peak latency, and odRNFL explained variance in congruent reaction time and congruent P3 peak latency. CONCLUSIONS:Persons with MS exhibited poorer attentional inhibition and slower processing speed, yet higher MPOD and odRNFL levels were independently associated with greater attentional inhibition and faster processing speed among persons with MS. Future interventions are necessary to determine if improvements in these metrics may promote cognitive function among persons with MS.