We placed human donor corneas in M-K medium at 4° C for 24 hours, cultured them in minimal essential medium at 34° C for two to five weeks, and then either (1) placed the corneas in M-K medium at 4° C for 48 hours before transplantation (Group 1, 47 eyes); (2) placed the corneas in M-K medium at 4° C for 16 hours before transplantation (Group 2,17 eyes); or (3) transplanted the corneas without postculture cooling to 4° C (Group 3, 11 eyes). We compared the corneas preserved by organ culture with an equal number of corneas transplanted during the same period, but preserved only in M-K medium at 4° C for one to four days. The central endothelial cell losses noted two months after keratoplasty were significantly greater in the organ-cultured corneas than in the M-K-preserved corneas in each of the three groups. The mean endothelial cell loss in the 11 organ-cultured corneas in Group 3 was significantly less than that in the 64 organ-cultured corneas in Groups 1 and 2. The corneas in Group 1 were also examined one year after keratoplasty, and the cell losses in the organ-cultured grafts remained significantly greater than those in the M-K-preserved grafts. These results indicate that the culture of donor corneas in minimal essential medium at 34° C for several weeks (after storage in M-K medium at 4° C for 24 hours) decreases the ability of the endothelial cells to survive the trauma of keratoplasty, and that postculture storage at 4° C in M-K medium decreases this ability further. Photographic assay of central endothelial cell survival was a more sensitive indicator of the efficacy of the method of corneal preservation than was the clinical success rate, which was the same (96%) in both the organ-cultured and M-K-preserved grafts. New methods of corneal preservation should be tested by the endothelial cell assay technique.
Bibliographical noteFunding Information:
Supported in part by NIH grant EY 02037, Research to Prevent Blindness, Inc. and the Mayo Foundation.
- corneal organ culture
- corneal preservation
- corneal storage
- endothelial cell loss