Abstract
Abstract: :
Purpose: The spatial distribution is generally assumed to be monotonously decreasing to very low values in the periphery. However there are indications that this might not be true. The aim of this paper is to study 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. Since 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: Maps of the spatial distribution of the macular pigment optical density were obtained in 53 healthy subjects. In about half of the subjects we observed a distinct ring pattern at a mean distance of 0.7° of the fovea. In some subjects the ring had an even larger optical density than the central peak. An exponential decaying density as a function of eccentricity in combination with a Gaussian distributed ring pattern gave a good description of the data for both methods. The widths of the central peak and the Gaussian ring were similar. Also, the eccentricity at which the ring peaks was similar. The prominence of the ring did not depend on parameters like age or gender, smoking or diet. Conclusions: Both reflectance and autofluorescence maps show similar ring patterns in the distribution of the macular pigment.
Keywords: macular pigment