Our long range goal is to delineate specific aspects of lens aging and cataractogenesis at the molecular level, particularly the photobiologic effects due to longwave ultraviolet (UVA) radiation. As well as utilizing our spectroscopic analysis (ultraviolet (UV) absorption and transmission, fluorescence, phosphorescence and EPR spectroscopy), we have expanded our approach to include nuclear magnetic resonance (NMR) spectroscopy to study the normal lens and the effects of UV radiation on human and animal lenses and protein extracts. Our current aim is to further expand this approach in order to develop surface scanning NMR capable of monitoring specific parameters (e.g., organophosphate metabolism) in the living animal lens as delineated by our in vitro studies (on human and animal lenses). The foregoing in vitro studies will enable us to determine age related changes with respect to biophysical aspects of lens transparency in aging and senile cataractogenesis. Our photobiologic studies have enabled us to develop an in vivo method (UV slit lamp densitography) to screen for and measure direct and photosensitized lens damage. The projected surface scanning NMR studies could result in the development of a second in vivo screening method. The in vivo UV-visible slit lamp densitography will be performed on patients prior to cataract surgery; the intact lens is then photographed (with the CCRG method) immediately after extraction and then subjected to the optical and NMR spectroscopic analyses. These studies will permit a direct correlation between an in vitro and in vivo cataract classification system as well as determining objective spectroscopic parameters associated with various types of human cataract. Since aging is accompanied by measureable changes in lens transparency and fluorescence, the foregoing approach on fresh whole eye bank eyes (UV-visible slit lamp densitography) followed by a second series of UV-visible photographs and CCRG photographs on the excised lens will provide significant data on the processes associated with the documented age realted changes in lens fluorescence, phosphorescence and transparency. These data will be correlated with directs spectroscopic analyses on the intact lens and should provide new information on the age related changes resulting in the development of localized scattering elements (opacities) which eventually become manifest in the vast majority of aging """"""""normal"""""""" lenses.
