In vivo MRI and fluorescence studies on the ocular lens.

During the past two decades progress in biophysical technology has made it possible to monitor aging and pre-cataractous as well as cataractous changes in the ocular lens in vivo as well as in vitro. Because they are non-invasive these techniques can be performed in vivo and utilized as screening methods to detect and predict eventual lens opacification, and they should also provide increasingly important information to help clarify the cataractogenic process. Three such biophysical approaches can now be employed in vivo; these include lens fluorescence, light scattering measurements and magnetic resonance imaging (MRI) T2 analyses (1-27). We have utilized two of these methods (fluorescence spectroscopy and MRI measurements of lens water [T2] phases) to delineate normal age-related and pre-cataractous changes in a series of human subjects and in patients with early lens opacities. The parameters employed for these studies were based on data accumulated from in vitro experiments on human lenses and in vivo and in vitro data from animal experiments (2, 6-8, 18, 19, 22, 25-27).