Monitoring in vivo lens changes. A comparative study with biochemical analysis of protein aggregation

In this study the AA attempted to evaluate the relationship between lens optical density and lens fluorescence determined in vivo, with some specific (in vitro) biochemical changes occurring during cataract development. Special attention has been given to the comparison between diabetic and non diabetic cataracts. Prior to surgery all lenses were analysed by Scheimpflug photography to evaluate the topography of opacities and fluorescence distribution. Individual lenses were separated into cortex and nucleus and the amount of high molecular weight (HMW) protein aggregates was determined by FPLC (Fast Performance Liquid Chromatography). The results found in this study have shown that, as it would be expected, diabetic cataractous lenses present higher fluorescence levels than senile cataracts. It has also been shown that the increase in lens optical density, determined by Scheimpflug photography is clearly related to the increase in the amount of HMW-aggregates. Furthermore, in diabetic cataracts, a good correlation between protein aggregation and lens fluorescence determined in vivo has been found. Thus, it seems that in diabetic cataracts chemical or metabolic mechanisms leading to the production of fluorescent chromophores may be related to protein aggregation and therefore to the major processes involved in cataract development.