Macular Pigment Shows Ringlike Structures

Abstract

PURPOSE. The spatial distribution of macular pigment is generally assumed to monotonously decrease to very low values in the periphery. However, there are indications that this picture may be too simple. The purpose of this study was to examine the spatial distribution of the macular pigment optical density. METHODS. Fundus reflectance and autofluorescence maps at 488 and 514 nm Argon laser wavelengths were acquired in 53 healthy subjects with a custom-built scanning laser ophthalmoscope. Because the lens and the macular pigment are the only absorbers in this wavelength region, digital subtraction of log reflectance and log autofluorescence at the two wavelengths provides density maps of the sum of both absorbers. RESULTS. In approximately half of the subjects, we observed a distinct ring pattern at a mean distance of 0.7°of the fovea. In a few subjects, the ring had an even larger optical density than did the central peak. A simple model with an exponentially decaying density as a function of eccentricity, in combination with a Gaussian-distributed ring pattern, yielded a good description of the data for both methods. The widths of the central peak and the Gaussian ring, and also the eccentricity at which the ring peaks, were similar for both methods. The prominence of the ring did not depend on age and gender. CONCLUSIONS. Both reflectance and autofluorescence maps showed ring patterns in the distribution of the macular pigment, which probably follow the inner plexiform layer. (Invest

Heritability of the spatial distribution and peak density of macular pigment: a classical twin study

“…22,23 In general, the MP concentration peaks at the foveal centre where Z predominates and declines rapidly with eccentricity into the parafovea where L becomes the dominant carotenoid. [24][25][26] However, imaging techniques have revealed interesting variations in SDMP such as varying peak widths and ring-like structures, 23,27,28 anatomical differences such as foveal width and slope 29,30 can partially account for these although the reasons for their existence are not fully known.…”

Macular pigment optical density measurements: evaluation of a device using heterochromatic flicker photometry

“…5 Typically, the concentration of the MP is maximal at, or near, the fovea and rapidly decreases with eccentricity. [6][7][8] Because of its pre-receptorial location, MP is thought to shield the retina from deleterious effects of high-energy blue light (l B320 to 450 nm), by partly absorbing it. [9][10][11] As it functions as an anti-oxidant, MP may protect the retina by scavenging of free radicals formed by oxidative stress.…”

Repeatability of the macular pigment spatial profile: A comparison of objective versus subjective classification

“…1997; Kirby et al. 2009, 2010) and also by imaging using two‐wavelength FAF (Berendschot & van Norren 2006; Delori et al. 2006; Dietzel et al.…”

“…Various techniques have been described including objective analysis of secondary maxima–minima pairs (Delori et al. 2006) and mathematical analysis of a combination of an exponential and Gaussian fit to the data distribution (Berendschot & van Norren 2006). Quantification analysis of MP derived from FAF images has been used to characterize different MP spatial profile phenotypes (Trieschmann et al.…”

“…2006). If MP spatial profile classification is based on deviations from an exponential fit to the data (Berendschot & van Norren 2006; Nolan et al. 2008; Huntjens et al.…”