[Penetrating keratoplasty with long-term cryopreserved corneas]

Since March 1986, the authors studied the simplified corneal cryopreservation technique with their "QL Bio-Freezer". After successful animal experiments, 34 patients (35 eyes) were performed penetrating keratoplasty with human cadaver corneas cryopreserved 9 to 473 days, averaging 108 days. After following-ups of 1 1/2 to 28 months, 22 of the corneal grafts remained clear, 6 semitransparent, and 7 cloudy. A total of 25 eyes had their visual acuity improved significantly. The results show that the cornea cryopreservation technique with the simplified "two-step" method is a noteworthy clinical practice.