[Alcohol-induced morphologic and biochemical corneal changes]

In our cornea bank, it was noticed that corneas from donors with alcoholism seemed to be of lower quality than corneas from other donors. High blood ethanol concentrations can induce high alcohol concentrations in aqueous and vitreous humor. This could be demonstrated in the case of a lethal alcohol intoxication. We conducted in vitro experiments to clarify the question of alcohol-induced changes of corneas. The corneas were stored in a standardized culture medium including ethanol, formic acid, methanol, and acetaldehyde in concentrations to be expected in chronic alcoholism. During cultivation over 4 weeks, endothelial morphology and extent of aspartic acid racemization in stromal proteins were evaluated. The extent of aspartic acid racemization served as a biochemical parameter of alcohol-induced protein changes of the corneas. In the in vitro experiments, a drop in the endothelial cell counts could be seen in corneas stored in culture medium with acetaldehyde. The extent of aspartic acid racemization increases in corneas stored in medium containing ethanol, which obviously is the result of alcohol-induced protein degradation. High concentrations of ethanol and its metabolics can be detected in vitreous and aqueous humor in chronic alcoholism. Clearly, these concentrations have a direct toxic effect on the corneal endothelium (acetaldehyde) and on the stromal proteins (ethanol).