Abstract
Abstract: :
Purpose: We have investigated lipofuscin–based spectroscopy as a non–invasive, in–vivo optical method to measure human macular pigment. Potentially this method can provide a rapid, objective, and sensitive test for macular pigment concentrations including their spatial distribution throughout the foveal region. Methods: Lipofuscin fluorescence ("autofluorescence") of the retina can be selectively excited with wavelengths that either overlap or do not overlap the absorption of macular pigment in the human retina, such as 488 nm and 532 nm, respectively. Using a simple imaging setup with CCD camera detection, sequential blue and green light excitation, and digital image subtraction, we have compared the lipofuscin fluorescence levels obtained from the peripheral retina with fluorescence levels in the foveal region, and derived macular pigment concentrations as well as their distributions in more than100 human subjects. For a subgroup of subjects we compared the results with macular pigment levels measured with Raman spectroscopy. Results: Autofluorescence–based macular pigment images provide rapidly obtainable information of macular pigment regarding concentration levels, spatial extent, and symmetries. In healthy retinas there appears to be a good correlation with concentration results obtained with Raman spectroscopy. Conclusions: Autofluorescence–based macular pigment measurements are an attractive possibility for the non–invasive measurement of macular pigments with a simple, inexpensive, rapid, and objective optical method in healthy humans.
Keywords: macular pigment • optical properties • age-related macular degeneration