Epithelial downgrowth after penetrating keratoplasty.

Epithelial downgrowth after penetrating keratoplasty in very uncommon. This paper describes a case in which epithelium invaded the anterior chamber through a fistula in the suture scar from a cataract operation 15 years previously. The epithelium completely circled the endothelial margin of the corneal graft but did not advance into the centre of the graft. Traumatized corneal endothelial cells lose their property of contact inhibition, which permits epithelial growth, whereas normal endothelium is able to resist epithelial downgrowth.