Macular response to supplementation with differing xanthophyll formulations in subjects with and without age-related macular degeneration.

Abstract

Our aim was to investigate the macular response to three different supplements containing lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ) in normal subjects and those with age-related macular degeneration (AMD). Macular pigment optical density (MPOD) and serum xanthophyll concentrations were measured in normal (n = 31) and AMD subjects (n = 32), randomly assigned to: group 1 (20 mg L, 2 mg Z, 0.3 mg MZ), group 2 (10 mg L, 2 mg Z, 10 mg MZ) or group 3 (3 mg L, 2 mg Z, 17 mg MZ). MPOD was measured at baseline, 2, 4, 6 and 8 weeks and at 0.25°, 0.5°, 1.0° and 1.75° of eccentricity using customised heterochromatic flicker photometry and serum xanthophylls by HPLC. MPOD increased significantly at all eccentricities in each group (p < 0.05), except at 1.75° in group 3 (p = 0.242). There was no difference in MPOD measurements between AMD and normal subjects, except for group 2, where AMD subjects exhibited a greater response at 1.75° (p = 0.012). Final serum concentrations of MZ were positively and significantly related to final MPOD values at each eccentricity in all subjects. Targeted analysis of those subjects receiving the MZ-containing supplements exhibited stronger relationships between serum MZ concentrations and MPOD at 0.25° in group 3 than group 2; in group 2 all associations were positive, but only significant at 1.75°. Serum concentrations of MZ were strongly correlated with MPOD after 8 weeks of supplementation with the group 3 formulation, but the inclusion of L in the group 2 formulation may result in greater MPOD augmentation across the spatial profile.