Macular pigment density in healthy subjects quantified with a modified confocal scanning laser ophthalmoscope

In the industrialized world age-related macular degeneration (ARMD) is the leading cause for legal blindness beyond the age of 65 years. Recent studies indicate that the density of the macular pigment (MP) may play a central role in the development and progression of age-related maculopathy (ARM). We present results of measurements of macular pigment density (MPD) with a modified confocal scanning laser ophthalmoscope and compare macular pigment density values obtained from reflectance and autofluorescence images in healthy subjects.

A modified confocal scanning laser ophthalmoscope (Heidelberg Engineering, Heidelberg) was optimised for fundus reflectance and autofluorescence images at 488 nm and 514 nm. For autofluorescence imaging a band pass barrier filter with a short wavelength cut off at 530 nm was used. MPD maps were obtained, and MPD was evaluated within two degrees around the foveal center. In this study we included 109 healthy subjects aged from 18-75 years.

Average MPD ranged between 0.16 density units (D.U.) and 0.22 D.U. depending on the techniques used for the measurement. Using the reflectance method the mean MPD was 0.16+/-0.06 D.U., whereas a MPD of 0.22+/-0.07 D.U. resulted from autofluorescence images with the 530-nm barrier filter.

This study demonstrates the good feasibility of MPD measurements with a modified confocal SLO. In agreement with previous studies we found higher macular pigment density values calculated from autofluorescence images than from reflectance images. We could not find any differences in MPD related to age and gender. Prospective longitudinal studies to verify the influence of MPD on the development and progression of ARM are needed.