IN-VIVO LIGHT-SCATTERING INTENSITY IN THE LENS VERSUS IN-VITRO SPECTRAL TRANSMISSION IN THE NUCLEAR REGION

In order to understand the correlation between nuclear opacity and spectral light transmission factor, the in vivo light scattering intensity of Scheimpflug lens images and the light transmission through slices of surgically removed nucleus were examined densitometrically as well as spectrophotometrically respectively, using both human and Brown Norway rat lenses. The experiments using rat lenses showed that the increase of the light scattering intensity in the nuclear regions is correlated with a decrease of the spectral transmission factor. The transparent anterior cortical region did not influence the light transmission (T%) through the nucleus. No significant influence was seen from the application of freezing and thawing procedures to measure light transmission. The examinations of the human subjects which were based on the rat study showed that the light transmission of nuclear cataracts objectively evaluated as grade I was almost the same as that observed in noncataractous nuclei. The light transmission of nuclear cataracts graded II or above, however, showed around 50% of the spectral light transmission of noncataractous nuclei.