Association of age and macular pigment optical density using dual-wavelength autofluorescence imaging

Abstract

Background: Several lines of evidence suggest that macular pigment may play a protective role against age-related macular degeneration, but the influence of age on macular pigment density levels remains unclear. This study was designed to investigate the relationship between age and the normal distribution of macular pigment optical density (MPOD) values surrounding the fovea.

Methods: Consecutive healthy subjects with no evidence of ocular disease were enrolled in this study. After inclusion, MPOD values were measured at specific eccentricities (0.5, 1, and 2 degrees) from the foveal center using a dual-wavelength autofluorescence method employing a modified confocal scanning laser ophthalmoscope. Whenever both eyes were eligible, one was randomly selected for analysis. The correlation between age and MPOD values was investigated using regression analysis.

Results: Thirty subjects (30 eyes) were included (mean age 48.6 ± 16.4 [range 23-77] years). Significant differences were found between MPOD values measured at 0.5, 1, and 2 degrees from the center of the fovea (0.49 ± 0.12 density units, 0.37 ± 0.11 density units, and 0.13 ± 0.05 density units, respectively, P < 0.05). Significant correlations between age and MPOD values at 0.5 and 1 degree were found (P ≤ 0.02). Values measured at 2 degrees did not correlate significantly with age (P = 0.06).

Conclusion: In healthy subjects, MPOD values were highest near the foveal center. These values appeared to increase during adulthood (peak at 45-50 years), followed by a gradual reduction after 60 years of age.

Keywords: age; association; dual-wavelength autofluorescence imaging; macular pigment optical density.

Figure 1

Macular pigment optical density map of one eye included in the study. Notes: The image analyzed is demonstrated on the right side of the dialog. Two yellow lines mark the point used for radial analysis. The red and blue circles demarcate areas of 0.5 and 2.0 degrees from the center of the fovea, respectively. On the upper left side of the dialog there is a diagram with a normal radial distribution of macular pigment optical density around the center of the fovea. On the lower left side, the box shows numerical values for macular pigment optical density in the specific eccentricities analyzed.

Figure 2

Macular pigment optical density values at 0.5, 1.0, and 2.0 degrees of retinal eccentricity versus age. Abbreviation: HRA, Heidelberg Retinal Angiography.