The Effect of Amniotic Membrane Transplantation on Corneal Epithelial Cell Proliferation

ABSTRACT

PURPOSE: to investigate the effect of amniotic membrane transplantation (AMT) on corneal epithelial healing. METHODS: A 4-mm epithelial debridement was made in central rabbit cornea. Then, human amniotic membrane was transplanted (AMT group) or a contact lens was applied (contact lens group). The contralateral eyes were unwounded as controls. After surgery 5-bromo-2'-deoxyuridine (BrdU) was injected via ear vein. Each corneal tissue including the limbus was obtained on postoperative 12, 24 and 48 hours. Proliferating cell nuclear antigen (PCNA) in limbal and peripheral corneal epithelium and keratinocyte growth factor (KGF) in limbal stroma were immunolocalized by immunohistochemical method. Incorporation of BrdU in limbal and peripheral corneal epithelium was visualized by indirect immunofluorescent method. RESULTS: AMT group significantly accelerated the expression of PCNA and BrdU at limbal and peripheral corneal epithelial cells. The expression of PCNA and BrdU showed a peak at 24hr in both groups and increased in limbal epithelial cells more than peripheral corneal epithelial cell in AMT group. The expression of KGF on limbal keratocyte increased in AMT group more than contact lens group and coincided wiht the expression pattern of PCNA and BrdU. The number of keratocyte in significantly decreased in contanct lens group compared wiht AMT group. CONCLUSION: AMT enhanced corneal epithelial wound healing in vivo by stimulating limbal epithelial proliferation which is indirectly mediated in part by upregulating the expression of KGF, which is a potent epithelial mitogen secreted by limbal keratocytes.