Digital image analysis of cultured rat lens during oxidative stress-induced cataractogenesis

Isolated rat lenses were exposed to oxidative stress generated by 100 microM H2O2, 2 mM ADP and 100 microM ferrous ammonium sulfate. Oxidation-induced cataract formation was followed by measuring loss of transmitted light intensity using quantitative digital image analysis, which offers distinct advantages over conventional photography. In the presence of oxidants, total and average light transmitted by the lens decreased exponentially as a function of time; the cortex showing a greater rate of decline in transmitted light intensity than the nucleus, which led to a change in the distribution pattern of light intensity. Lenses developing oxidative cataracts also showed a significant increase in diameter and an increase in the total wet weight. Maximal increase in lens diameter preceded maximal decrease in light intensity. These studies demonstrate the utility of quantitative image analysis in studying changes in lens geometry and transparency, and suggest that cataract formation is a single rate process.