Corneal Wound Healing: Immunohistological Features of Extracellular Matrix Following Penetrating Keratoplasty in Rabbits

Purpose: To study the distribution and the constituents of the extracellular matrix in the cornea during wound healing following penetrating keratoplasty (PKP). Methods: Penetrating keratoplasty (PKP) was performed on albino rabbit eyes, and immunohistochemical techniques were used to determine the distribution of types I, III, IV collagens, large proteoglycans, chondroitin 6-sulfate, chondroitin 4-sulfate, and vimentin. The expression of these substances was determined at postoperative times of 3 days, 1 week, 2 weeks, 1 month, and 3 months. Results: By day 3, staining for type IV collagen was observed along the host-graft junction. By day 7, staining for type III collagen, large proteoglycans, and chondroitin 6-sulfate had increased in the repair region but then decreased with increasing postoperative times. Epithelial wound healing required more than one month, whereas the remodeling of Descemet's membrane did not terminate until 3 months after PKP. Conclusion: These results suggest that type III collagen, large proteoglycans, and chondroitin 6-sulfate probably play important roles in corneal wound healing after PKP.