Abstract
Abstract: :
Purpose: To evaluate the biocompatibility of the corneal substitutes using PLGA scaffold, type I collagen film, type I collagen film combined with amniotic membrane (AM) and lyophilized homologous cornea in severely damaged ocular surface disease. Methods: Rabbits were distributed into four experimental groups. (1) Type 1 collagen film : group A (2) Type I collagen film combined with AM : group B (3) lyophilized homologous cornea : group C (4) PLGA scaffold : group D. Discs in 7 mm diameter were inserted into the intralamellar stromal pockets of severely damaged corneas in group A, B, C and normal cornea of group D. And then corneal windows in 3 mm diameter were made on the upper lamellar cornea in group A, B, C. In 2 months of follow-up, clinical evaluation including corneal neovascularization, opacity and transparency of the graft materials were performed weekly. At 4 and 8 weeks, inflammatory reaction and fibroplasia were evaluated histologically. Immunohistochemistry was used to identify the type of collagen synthesis and myofibroblasts by α-SMA stain. Results: Corneal windows were completely reepithelized by postoperative days 3 to 9, and more rapid reepithelization were shown in group B and C than group A. Corneal neovascularization, opacity, inflammation, and degradation of collagen film were decreased more in group B than in group A. No inflammation and transparent graft material were shown in group C. Group D showed rapidly degraded graft materials and severe inflammation in recipient cornea. Immunohistochemical studies showed many corneal stromal fibroblasts in and around graft materials in group B and C, and more myofibroblasts in group A and D which had severe inflammation. around graft materials. The abnormal increase of type III collagen systhesis was observed in group A. Conclusion: The type I collagen film combined with AM and the lyophilized homologous cornea were more stable in the severely damaged cornea than the PLGA scaffold and the type I collagen film. These results suggest that the collagen film combined with AM and lyophilized homologous cornea could be clinically useful for the treatment of ocular surface injury including corneal deep ulceration and upper stromal opacity, and could be used as a carrier of cell therapy for the recovery of the healthy normal cornea.
Keywords: 374 cornea: stroma and keratocytes • 369 cornea: clinical science