Metabolic changes in donor corneas during cold storage – challenging stereotypes

Abstract: It has been recently shown that cold storage at 2-8°C is not neutral towards metabolic properties of the cornea. The aims of this study were to reveal: the kinetics of biochemical changes in human corneas during cold storage and the time of storage when the preserved corneas show the biggest biochemical similarities to in vivo ones. Twenty human corneas were obtained post-mortem from ten 60 to 71-year-old donors and preserved in Eusol-C at +4°C for 14 days. The control samples were the tissues stored at -80°C immediately after collecting them from cadaver eye globes. The daily changes in metabolic profiles of the samples were investigated with HR MAS 1H NMR spectroscopy. 25 metabolites were detected and assigned in the corneas. The significant differences in metabolic profiles between Eusol-C-preserved and non-preserved tissues, and between the corneas stored for 14 days comparing to 7-days samples, were revealed. The main differences between the samples were related to the levels of ATP, formate, lactate, glycine and butyrate in the tissues. The corneas preserved for 2 weeks were shown to have the biochemical contents more resembling the in vivo ones than the corneas preserved for one week. The results of this study suggest that from the biochemical point of view the cornea transplantation or any other procedure associated with a removal of the cornea from the storage medium should be performed after two weeks of the hypothermic preservation in Eusol-C.