Reflectance spectrophotometry in the human ocular fundus.

Spectrometric investigations were carried out in normal human maculae and optic discs and in those with pathological findings (50 eyes in total). Reflection spectra were measured by illumination of various points of the fundus, using a highly sensitive photon-counting technique. It is necessary to distinguish diffusely reflected light from regularly reflected light, as we found marked differences in the spectra of diffusely reflected light between normal eyes and those with pathological findings. In optic atrophy cases, the intensity of light reflected from the optic disc (510-600 nm) was remarkably higher than normal. In findings of proliferative diabetic retinopathy, the reflected light intensity showed a steeper slope, beginning at 580 nm, in comparison with normal findings.