Raman detection of pigments in the human retina

We have used resonance Raman scattering as a non-invasive optical technique to measure the concentration of carotenoid pigments in the human retina. The technique is highly sensitive and specific strength scales linearly with actual macular carotenoid content as measured by high-pressure liquid chromatography. This will facilitate studies of carotenoid distributions and their role in degenerative diseases of the eye and may allow for the rapid screening of carotenoid levels in large populations at risk for vision loss from age-related macular degeneration, the leading cause of blindness in the elderly in the US.