AIM: To monitor long-term changes of matrix metalloproteinase-2(MMP-2)in human tears fluid after laser in situ keratomileusis(LASIK).

METHODS: Thirty-two myopia cases(64 eyes)underwent uneventful LASIK were enrolled in the study. Tear fluid were collected and MMP-2 expression was analyzed by Western-bolt assay preoperatively and postoperatively on 15d, at 1, 3mo, and 1a.

RESULTS: LASIK increased the concentration of MMP-2 in human tear fluid. At 15d postoperatively, the magnitude of MMP-2 was 1.4 times that of preoperative, thereafter subsided, but didn't return to preoperative level by 3mo(P<0.05). Up to 1a after surgery, the concentration of MMP-2 almost recovered(P>0.05).

CONCLUSION: MMP-2 is significantly expressed in human tear fluid after LASIK, then subsided with time, but didn't return to preoperative level by 3mo and almost recovered up to 1a, indicating wound healing of LASIK would continue up at least 3mo after surgery and almost recovered 1a postoperatively.