Macular Pigment Optical Densitometry in the Elderly: Findings in a Large Biracial Mid–South Sample and Effect of Optical Blur in Pseudophakic Subjects

Abstract

Abstract: : Purpose: To report the macular pigment optical densitometry (MPOD) findings in a large biracial population sample of Mid–South older adults and to determine if MPOD measurements are adversely affected by optical blur in pseudophakic elderly subjects. Methods: MPOD was estimated with a heterochromatic flicker photometry–based instrument at 0.5 degrees of eccentricity from the fovea, using an elderly–friendly technique requiring only 3 repetitions per target. Measurements were successfully obtained in a biracial sample of 270 (15% African–American), 79.1 ± 3.6 year–old subjects of both sexes (M=127; F=143) participating in the Dynamics of Health, Aging, and Body Composition (Health ABC) Age–Related Maculopathy Ancillary (ARMA) Study. The effect of optical blur was investigated in 30 pseudophakic participants (M=11; F=19) in the same age range by comparing the baseline MPOD, obtained with an optimal correction based on the perceived sharpness of a ring–shaped test target, with MPODs obtained with a ±1.00–diopter (D) optical blur. Results: The mean MPOD in our population was 0.35 ± 0.21 (1 SD). The interocular correlation (IOC) was high (Pearson’s r: 0.781). The mean MPOD was overall higher (p=0.0005) in lutein supplement users (LSUs: 0.39 ± 0.20; n=104) than in non–LSUs (0.32 ± 0.22; n=162), and this difference was greatest for male subjects (LSUs: 0.38 ± 0.22; non–LSUs: 0.30 ± 0.21; p=0.004). Female non–LSUs had, on average, higher MPOD values (0.34 ± 0.22) than male non–LSUs, but this difference was not statistically significant (p=0.057). The ±1.00 D optical blur did not cause differences in the MPOD estimates (Pearson’s r: 0.887 and 0.939 for positive and negative blur, respectively), nor did it affect adversely test duration (about 15–17 minutes per eye under either condition) in the pseudophakic subjects. Conclusions: Mid–South older adults appear to have average MPOD results and an IOC comparable to previous studies, except that women tended to have higher MPOD values. MPOD testing was insensitive to an optical blur of ±1.00 Ds in pseudophakic subjects, who therefore do not require time–consuming supplemental correction at near beyond the standard one provided by the instrument.

Keywords: macular pigment • aging • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology