Lamellar keratoplasty with a graft of lyophilized acellular porcine corneal stroma in the rabbit.

Abstract

OBJECTIVE: To evaluate the efficacy of lamellar keratoplasty in the rabbit using a graft of lyophilized acellular porcine corneal stroma (APCS). ANIMAL STUDIED: Twelve adult 2-2.5 kg Zealand white rabbits were studied. PROCEDURE: The cell components of the porcine cornea were removed by the means of enzymatic digestion, freezing, and thawing and then APCS was lyophilized. The 6.5 mm diameter APCS was implanted on a 6.0-mm diameter keratectomy wound each of 12 rabbits. The postoperative clinical and histological evaluations were performed in the early, intermediate, and late periods. RESULTS: All corneal wounds healed. Ten of the 12 grafts of APCS were integrated completely with the receptive cornea except two grafts scraped partially off by the eyelid. The blepharospasm, ocular discharge, and edema of the cornea were marked 1 week after transplantation. New vessels invaded the graft after week 2 and regressed after week 8. The cornea became transparent gradually. The histological evaluation showed that the epithelium on the graft stratified normally post surgery. The keratocytes of the recipient grew into the graft and were proliferative at week 4. The inflammatory cells and new vessels were observed before week 8. The fibrosis in the graft was revealed at week 4 and lessened at week 8. The histological structure of the cornea after surgery was similar to the normal cornea at week 32. CONCLUSIONS: APCS can recover the integrity of the rabbit's cornea and become transparent in vivo. APCS is an effective graft for lamellar keratoplasty in the rabbit.