Modification of the antibiotic system in M-K medium.

Corneal endothelial cell function and ultrastructure were studied in rabbit corneas stored in M-K medium with different antibiotics. At concentrations about ten times greater than their minimum inhibitory concentrations, tobramycin, gentamicin, polymixin B, penicillin and streptomycin mixture, cephaloridine, and cephalothin did not damage corneal endothelia. Corneas stored in M-K medium with bacitracin did not have temperature reversals as did other corneas after storage. This is probably not significant since they maintained almost constant thickness and the endothelial layer remained intact.