Page 246 - Vibrational Spectroscopic Imaging for Biomedical Applications

222 Cha pte r Se v e n

to explore correlations between MP patterns and retinal health and
pathology in future clinical studies.
In dermal applications, the Raman method can rapidly assess
dermal carotenoid content in large populations. Spatially resolved
RRI is not needed due to the rather smooth spatial change of skin
carotenoid levels. Instead, composite skin carotenoid levels can be
measured with simple, spatially integrating Raman detection. Mea-
surements have to be limited to tissue sites with a thick stratum cor-
neum. In this case the probed tissue is thicker than the penetration
depth of the excitation light, thus avoiding absorption of hemoglo-
bin. Furthermore, the stratum corneum tissue in the palm of the hand
or the sole of the foot is free of melanin. A correlation of our Raman-
derived carotenoid data with HPLC-derived serum levels again con-
firms the validity of the carotenoid Raman detection technique in the
physiologically relevant concentration range under these measuring
conditions.
Carotenoid RRS detection has exciting potential for in-vivo appli-
cations. In the nutritional supplement industry it is already established
as an objective, portable device for the monitoring of the effect of carot-
enoid-containing supplements on skin tissue carotenoid levels. In oph-
thalmology, it may become a fast screening method for MP levels in the
general population. In epidemiology, it may serve as a noninvasive
novel biomarker for fruit and vegetable intake, replacing costly plasma
carotenoid measurements with inexpensive and rapid skin Raman
measurements. In neonatology, it may serve as a noninvasive method
to assess carotenoid levels in prematurely born infants to investigate
their correlation with oxidative stress related degenerative diseases.
Lastly, due to its capability of selectively detecting lycopene, the tech-
nology may be useful to investigate a specific role of lycopene in the
prevention of prostate cancer and other diseases.

References
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Spectroscopy, G. Britton Liaaen-Jensen, and H. Pfander (eds), Birkhäuser, Basel,
1995, pp. 135–146.
2. D. M. Snodderly, P. K. Brown, F. C. Delori, and J. D. Auran, “The Macular
Pigment. I. Absorbance Spectra, Localization, and Discrimination from Other
Yellow Pigments in Primate Retinas,” Investigative Ophthalmology & Visual
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3. D. M. Snodderly, J. D. Auran, and F. C. Delori, “The Macular Pigment. II. Spatial
Distribution in Primate Retinas,” Investigative Ophthalmology & Visual Science,
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4. Age-Related Eye Disease Study Research Group, “The Relationship of Dietary
Carotenoid and Vitamin A, E, and C Intake with Age-Related Macular
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5. J. T. Landrum and R. A. Bone, “Lutein, Zeaxanthin, and the Macular Pigment,”
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