Author Of 1 Presentation
LB1217 - Macular pigment concentration and distribution in multiple sclerosis (ID 2084)
Abstract
Background
Oxidative stress is implicated in inflammation and neurodegeneration in multiple sclerosis (MS). Similar to the brain, the retina is susceptible to reactive oxygen species (ROS). Macular pigment (MP), consisting primarily of the carotenoids lutein (L) and zeaxanthin (Z) blocks deleterious blue light, and provides anti-oxidant protection. To date, there has been a paucity of study of MP in MS.
Objectives
To examine MP concentration and distribution in MS eyes relative to healthy control (HC) eyes using macular pigment optical density (MPOD) imaging.
Methods
In this cross-sectional study, 27 MS patients (47 eyes) and 19 HCs (37 eyes) underwent MPOD imaging on a Spectralis (Heidelberg) device. MP absorbs blue light, but allows the free passage of green light. MPOD imaging involves the subtraction of blue from green wavelength auto-fluorescence macular scans, providing the optical density (OD) of MP. Radii of interest for MPOD were 0°, 0.23°, 0.51°, 0.98° and 1.99° degrees of eccentricity from the fovea, as well as peak, and half-peak MPOD locations. Study participants completed dietary L & Z screening questionnaires. Mixed effects linear regression models were used in analyses.
Results
Mean MPOD at 0° was 0.52 density units (d.u.) (SD 0.14) in MS and 0.63 d.u. (SD 0.18) in HC eyes (difference: -0.10 d.u., CI: -0.18 - -0.01, p=0.027). The median MPOD peak location eccentricity was 0.08° (IQR: 0 - 0.12) in MS and 0.04° (IQR: 0 - 0.08) in HC eyes (difference: 0.10°, CI: 0.01 - 0.20, p=0.031). Mean MPOD at the peak location was -0.09 d.u. lower in MS eyes relative to HC eyes (CI: -0.18 - -0.01, p=0.04). In addition, the half-peak MPOD location, similar to the MPOD peak location, was situated further from the fovea in MS eyes relative to HC eyes (difference: 0.28°, CI: 0.10 - 0.47, p=0.002). Analyses adjusted for age, body mass index, sex, and L & Z dietary scores, showed similar differences for MPOD at 0° eccentricity, and at the peak MPOD location, between MS and HC eyes.
Conclusions
Our findings suggest MP concentrations are reduced in MS eyes, with peak and half-peak MPOD locations shifted further from the fovea than in HC eyes. Increases in ROS consuming antioxidant MPs, and/or dysfunction in proteins transferring carotenoids to the fovea, among other reasons, may help explain reductions in MPOD in MS eyes. Our preliminary finding warrant further study, in larger, prospective MS cohorts, including determination of their clinical relevance.