Inadvertent corneal button inversion during penetrating keratoplasty.

Inadvertent inversion of a corneal button during corneal transplantation for pseudophakic bullous keratopathy occurred with subsequent intense intraocular inflammation but a relatively compact graft. The diagnosis was made by a superficial corneal biopsy of Descemet's membrane, and a repeat corneal transplantation resulted in a clear graft and no evidence of epithelial downgrowth. Histology revealed the persistence of the donor epithelium on the inverted donor button but no residual endothelium on the externalized surface. Although laboratory attempts to duplicate an inversion of a corneal graft revealed that this occurs only with considerable difficulty, this operative complication may explain some of the unexpected primary graft failures reported in the literature.