Absorbance and Light Scattering of Lenses Organ Cultured with Glucose

Abstract

Purpose/Aim: Diabetes is one of the major factors related to cataract. Our aim is to determine if the attenuation of light through glucose treated lenses was due to light scattering from structural changes or absorbance from metabolic changes.

Materials and methods: Human and rat lenses were cultured in a medium with and without 55 mM glucose for a period of 5 days. Absorbance and light scattering were measured using a ultraviolet spectrometer. Aldose reductase and catalase activity, RAGE, and glutathione were measured using classical assays.

Results: Almost all of the glucose related attenuation of light through the human lens was due to light scattering from structural changes. Glucose treatment caused three absorbance band to appear at 484, 540 to 644 and 657 nm in both the rat and human lens. The optimum time point for equilibration of human lenses was found to be between 2 and 3 days in organ culture. Glucose caused a more significant effect on the opacity of human lenses compared with rat lenses. Since the levels of glutathione, catalase, and aldose reductase were reduced in glucose treated rat lenses compared with untreated lenses, glucose may have caused oxidative stress on the rat lens.

Conclusions: The absorbance and light scattering of glucose treated lenses in organ culture were quantitated for the first time which could be important for future studies designed to test the efficacy of agents to ameliorate the opacity. Almost all of the glucose related attenuation of light through the human lens was due to light scattering from structural changes and not absorbance from metabolic changes. Glucose caused a more significant effect on the opacity of human lenses compared with rat lenses. The lens model employed could be used to study the efficacy of agents that potentially ameliorate lens opacity.

Keywords: Cataract; glucose; lens; organ culture.