The Effect of Amniotic Membrane Transplantation on Corneal Epithelial Cell Proliferation

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.

The Effect of Early Amniotic Membrane Transplantation in the Rabbits' Corneal Ulcer by Staphylococcus Epidermidis

PURPOSE: Untill now, AMT at the early stage of corneal ulcer has been prohibited by the reasons that measurement of progression of ulcer by active pathogens was difficult through the transplanted amniotic membrane and anxiety about worsening by decreased permeability of antibiotics. This study has investigated the effect of early AMT in the bacterial corneal ulcer. METHODS: We made experimental bacterial corneal ulcer in 10 rabbits with Staphylococcus epidermidis, which typically has a more indolent clinical course. After certification of infection, fresh amniotic membranes, soaked by fortified antibiotics was transplanted to 5 eyes to which we dropped fortified antibiotics. And to another 5 eyes we applied only fortified antibiotics. After observing the progression of corneal ulcer for 4 weeks, we compared the degree of corneal opacity and histopathologic changes between the two groups to measure the effect of early AMP in the bacterial corneal ulcer. RESULTS: Corneal ulcer was healed in the all 5 cases of early AMT-performed group, And compared with the group without AMT, successful decrement of corneal opacity was observed in the 4 cases of early AMT-performed group. Histopathologic observation has revealed only mild inflammation and the maintenance of parallel architecture of stromal collagens. CONCLUSIONS: In the experimental corneal ulcer with Staphylococcus Epidermidis, we observed healing of the ulcer with decrement of corneal opacity, result from early transplantation of amniotic membrane, soaked in fortified antibiotics followed by dropping of fortified antibiotics at an early stage of ulcer.

Amniotic Membrane Transplantation in Perforation or Impending Perforation of Cornea

To evaluate the efficacy of amniotic membrane ransplantation(AMT) in the cornea that was perforated or impending perforation due to recalcitrant corneal ulcer or trauma, we performed AMT on 1 case of acid burn, 2 cases of thermal burn, 1 case of corneoscleral staphyloma with bullae due to previous ocular trauma, 2 cases of keratolysis as a graft rejection after keratoplasty, 3 cases of corneal ulcer. We used one or several layers of amniotic membrane(AM) that preserved in DMEM solution and 10% glycerin(1:1) under-70 degrees C or lyophylized form. As a result, the corneal perforations were prevented and the stable ocular surface were achieved. However, in case of neurotrophic keratopathy, epithelial rebreakdown was occurred after AMT, eventually epithelalization was fulfilled. Therefore, AMT may be a effective alternative method for treating corneal perforation or impending perforation that are refractory to conventional treatment.