Macular Pigment Optical Density in Age-related Macular Degeneration

Abstract

Purpose : Macular pigment is hypothesized to be protective. However, limited data is available on how macular pigment optical density (MPOD) differs across AMD stages or its association with other functional AMD biomarkers. This study compared MPOD at different radii between patients with age-related macular degeneration (AMD) and a control group, and the association of MPOD with dark adaptation (DA).

Methods : Prospectively designed, cross-sectional study. Patients with early, intermediate and late AMD and a control group of subjects older than 50 years were invited to participate. Included participants underwent dual-wavelength (488 and 514 nm) auto-fluorescence (Spectralis HRA+OCT, Heidelberg) for MPOD assessment; with measurements obtained in 3 concentric circles centered on the fovea with a radius of 1, 2 and 6 degrees. The optical density at the 6 degree radius circles was considered as plateau, and the optical density at and within the 1 and 2 degree radius circles was calculated relative to this plateau. Next, MPOD values for each radius circle and an average of total MPOD volume within the radius were calculated. Dark adaptation was assessed with the extended protocol of AdaptDx® (Maculogix, PA). Multilevel mixed models were used to determine the association of AMD grade and time to dark adapt with MPOD values (i.e. to consider the inclusion of two eyes from the same patient), accounting for age and use of AREDS supplements.

Results : We included 171 eyes of 87 patients; 116 with AMD (17 early 10%; 78 intermediate 46%; 21 late 12%) and 55 controls (32%). Mean age was 72.0 ± 7.2 and 64.7 ± 8.48, respectively. After controlling for age and AREDS stage, in the 2 degree radius circle (β = .09; p = 0.015) and in-between 1 and 2 degree radius circles (β = .08; p= 0.022) intermediate AMD was significantly associated with increased MPOD. In this cohort, after adjusting for the same covariates, MPOD was not a significant predictor of time to dark adapt.

Conclusions : Our results revealed that intermediate AMD stage is significantly associated with increased MPOD compared to controls. MPOD will be a potentially, useful imaging biomarker in AMD.

This is a 2020 Imaging in the Eye Conference abstract.