Raman Spectroscopy of Ocular Tissue - Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields - page 301

Fig. 12.13. a Schematics of experimental setup used for in vivo resonance Raman
imaging, RRI, of macular pigment distributions in the human retina. Light from a
blue laser source is projected onto the macula as a large-diameter excitation disk,
and the backscattered is imaged onto a CCD camera array. Two sets of filters are
used sequentially to selectively image light at the macular pigment molecules' C=C
Raman wavelength (Raman image) and at a slightly longer wavelength (offset im-
age). Afterward, the images are digitally subtracted and displayed as topographic
or three-dimensional pseudocolor images of the spatial concentrations of macular
pigment. b Photograph of subject measured with portable instrument developed for
use in eye clinics