[Transplantation of porcine type I atelocollagen into rabbit cornea]

To investigate corneal wound healing in rabbit after lamellar keratoplasty with porcine type I atelocollagen.

One hundred Chinese white rabbits, 80 rabbits were randomly divided into collagen materials group (group A) and allograft group (group B), and group A and B were operated for the lamellar keratoplasty in one eye. Rest 20 rabbits' eyes (40 eyes) were used as the source of allograft for group B. After operation, the rabbits' eyes were observed by naked eyes and slit lamp, and recorded the score of the transparency and neovascularization of the cornea. The rabbits were sacrificed at 3rd, 14th day, the 1st, 3rd, and 6th month (each group eight eyes). The corneas were observed by histopathology, and the epithelial cells marker protein K3 were detected by immunohistochemistry. The results were analyzed by Rank sum test.

The transparency of the cornea was increased gradually in A and B groups, and reached the peak on the 6th month (group A: χ(2) = 31.250, P = 0.000; group B: χ(2) = 32.566, P = 0.000). The difference had not statistics significance in the comparison of the transparency from the 1st to 6th month (Z = -1.414, 0.000, -0.743;P = 0.157, 1.000, 0.458). The two groups had corneal neovascularization after 7 days, the intensity of corneal neovascularization in A group increased gradually, reached the peak on day 14, then decreased gradually (χ(2) = 20.727, P = 0.001); the intensity of corneal neovascularization in B group increased gradually, reached the peak on day 14, and then decreased gradually (χ(2) = 25.562, P = 0.000). The difference had statistics significance in the comparison of the neovascularization of the cornea on the 6th month between A and B group (Z = -2.070, P = 0.038). Histopathology showed the collagen material nearly disappeared after 1 month of surgery and arrangement of collagen tends to be regular. On the 6th month, arrayed collagen was regular in general, but disordered partly.

Porcine type I atelocollagen can promote corneal cells regeneration. But it needs more study to be a cornea substitute that can completely replace the corneal allograft.