Purpose: To evaluate retrospectively the corneal endothelium in 15 eyes which showed clear cornea for 20 years or longer after penetrating keratoplasty.
Methods: The corneal endothelium was investigated in 15 eyes. The causative lesion had been keratoconus in 10 eyes and herpetic keratitis in 5 eyes. At the time of surgery, the patients were aged from 6 to 45 years, average 25.3 +/- 10.4 years. The endothelial cell density was measured 10 and 20 years after surgery by specular microscope. The relation between the rate of endothelial cell density loss and postoperative graft rejection, final visual acuity, causative corneal lesion, age of the patient, and age of the donor was evaluated.
Results: The endothelial cell population per mm(2) averaged 998 +/- 343 ten years after surgery and 852 +/- 245 twenty years after surgery. The rate of endothelial cell density loss thus averaged 12.1% +/- 16.3% during the last 10 years. This rate was independent of postoperative graft rejection, final visual acuity, causative corneal lesion, age of the patient, or age of the donor.
Conclusions: The corneal endothelial cells become stabilized 10 years after surgery in cases where the grafts remain transparent 20 years after surgery.