AIM: To study the expression of matrix metalloproteinase-9(MMP-9)and tissue inhibitor metalloproteinase-1(TIMP-1)after conjunctival flap covering in alkali-burned cornea.

METHODS: Rabbit cornea alkali-burns model was made, then 50 rabbits were randomly divided into experimental group(n=25)and control group(n= 25). At the same time the surgery of conjunctival flap covering was given to rabbits of the experimental group. The condition developing of alkali-burned cornea was observed by slit-lamp biomicroscopy, photography in two groups, and the expression of MMP-9 and TIMP-1 was identified by immunohistochemisty in different period.

RESULTS: Expression of MMP-9 increased on the 3^rd day, shown a peak on the 14^th day, and then decreased gradually. TIMP-1 expressed in the early phrase, and later, the level decreased on 7^th day. TIMP-1 level reached the lowest level on 14^th day, then increased and shown a peak on the 21^st day. MMP-9 level of the experimental group was significantly lower than that of the control group(the 3^rd, 14^th, 21^st, and 28^th day), while TIMP-1 level(the 3^rd, 14^th and 21^st day)was higher(P<0.05).

CONCLUSION: During the wound healing process, alkali-burned cornea has close relation with the expression of MMP-9 and TIMP-1. The treatment of conjunctival flap covering for the severe alkali-burned cornea was found to have good effect.