[Comparison of two sorts of bio-derived materials after being explanted in the repaired rabbit corneal defect]

To compare the effects of the denuded freeze-dried-amniotic-membrane and the denuded freeze-dried bovine corneal stroma when they were explanted to repair the corneal defect of rabbits.

The amenia from healthy human placentae were prepared with the method reported by LUO Jingcong, which were freeze-dried and sterilized. The bovine cornea was also denuded by trypsin, rinsed, freeze-dried, and sterilized. Twenty Japan rabbits were divided into group A (the amniotic group) and group B (the bovine-corneal-stroma group) at random. The defect was made, which was 7.5 mm in diameter and 1/3 of the thickness of the cornea, and the two kinds of materials were explanted to repair the defect. The vascularization and the changes of the operated eye were observed. The samples were taken at 2, 4 and 8 weeks for histological examination.

The explanted materials were not melted or excluded. There were visible neovessels in both groups, yet there was no significant difference between them. According to the histological observation, there was severe inflammation in both groups 2 weeks after operation, the fibroblasts were proliferated, and the collagen fibers were disorganized; however,the reactions became milder from 4 weeks after operations, and the neovessels could be seen in groups A and B; at 8 weeks, the collagen fibers were more organized in groups A and B; however,there was still a small area of disorganized fibers left.

The two materials can lead to rejection to some extent, and so they need to be improved.