Endothelial cell densities in donor and recipient tissue after keratoplasty.

A specular microscope was used to photograph the cell densities of the central cornea of the graft and the peripheral recipient cornea in a total of 32 human eyes. The follow-up period varied from 8 months to 13 years, with an average of 4.7 years. The mean endothelial cell count in the graft was 997 +/- 356 cells/mm2 and 1410 +/- 584 cells/mm2 in the recipient's peripheral cornea. The mean difference in cell counts between donor and recipient tissues was 413 +/- 718 cells/mm2 (29%). There were great disparities between graft and recipient cell densities. One patient with keratoconus had a graft/recipient differential in cell density of 3 to 1. In four cases the cell density was higher in the graft than in the recipient. Of these grafts, two had been stored in M-K medium and two had been cryopreserved. The great difference in cell density observed between the graft and recipient corneas strongly suggests that little, if any, cell migration occurs between graft and recipient. This suggests that the scar tissue forms a barrier to cell migration between graft and recipient.