Effects of moist-chamber and McCarey-Kaufman medium storage on the metabolic status of the cornea: a 31P-magnetic resonance analysis.

The rate of change in concentration of corneal phosphatic metabolites of cat corneas stored in moist chamber and McCarey-Kaufman (M-K) medium was determined in order to provide a basis for prediction of the corneal metabolic status at a given storage time. Perchloric acid corneal extracts were examined by phosphorus-31 magnetic resonance after storage at 4 degrees C of whole globes under moist-chamber conditions up to 48 h and of excised corneas in M-K medium up to 168 h. A significant decline in the corneal concentrations of ATP and a significant increase in inorganic phosphate occurred for both storage methods; however, depending on the metabolite, the rate of decline or increase was significantly greater for the moist-chamber-stored corneas. The phosphorylated sugars significantly increased and the glycerophosphodiesters significantly decreased in the moist-chamber-stored corneas, whereas both metabolites remained unchanged in the M-K-medium-stored corneas. There was no significant change in the dinucleotides and nucleoside diphospho-sugars during the time course for both storage methods. A threefold greater rate of decline was noted in the tissue energy modulus for the moist-chamber-stored corneas than for the M-K-medium-stored corneas (-0.0465 vs. -0.0121 modulus values/h). M-K medium was significantly more effective in the maintenance of high-energy phosphatic metabolites. The mathematical model for these rate determinations provides a basis for prediction of the corneal metabolic status at a given time in moist-chamber or M-K medium storage.