The Effect of Amniotic Membrane Gra ft on the Inhibition of Corneal Haze in Rabbit

ABSTRACT

This study was performed to investigate histopathologically the effect of amniotic membrane graft (AMG)on haze in deep stromal wound of cornea. The excimer laser phototherapeutic keratectomy (PTK)was used to create the wound model of 150 micrometerdepth, 6.0 mmdiameter area in 72 white rabbitsbilaterally.Each eye was randomized to three groups control (topical antibiotic alone), contact lens application and AMG. Corneal haze,the number of anterior stromal keratocytes and thickness of the regenerated stroma were evaluated after treatments in corneal wound, and also the morphological changes of anterior stroma connected with corneal haze were analyzed. The score of corneal haze in AMG group was significantly lower than those in the others at postoperative 3 days, 2, 4, 6 and 8 weeks. The anterior stromal keratocytes in AMG group significantly remained more than those in the others at postoperative 3 days. The number of keratocytes and thickness of regenerated stromal tissue in wound area of AMG group were statistically lower as compared with those of the other groups at postoperative 4 weeks. The architecture of stromal lamella was most reg-ular in AMG group. Transmission electron microscopic observation demonstrated that the cells in anterior stroma were the active fibroblastic cells with prominent rough endoplasmic reticulum at postoperative 8 weeks. These findings indicate that corneal haze is closely connected with proliferation of corneal stroma , suggesting that AMG on deep corneal stromal wound reduces corneal haze by preventing proliferation of abnormal collagen and fibroblasts at the anterior stroma of the wound area.