OBJECTIVETo investigate the dynamic changes of matrix metalloproteinase-9 (MMP-9) level in tear fluid within 12 months after laser in situ keratomileusis (LASIK).

METHODSTwenty-two myopic patients undergoing uneventful LASIK were enrolled in this study. Tear fluid samples were collected from the patients for measurements of MMP-9 level using Western blotting preoperatively, at 7 and 14 days, and at 1, 2, 3, 6, and 12 months after the surgery.

RESULTSMMP-9 concentrations in the tear fluid of post-LASIK patients showed a time-dependent variation pattern. MMP-9 reached its peak level in the tear fluid at 14 days postoperatively, which was 2.70 times the preoperative level; it gradually decreased thereafter but was still 1.38 times the preoperative level at 12 months after the surgery.

CONCLUSIONSMMP-9 concentrations in the tear fluid of post-LASIK patients show a time-dependent variation pattern and remains higher than the preoperative level even at 12 months after the surgery, suggesting that corneal wound healing after LASIK lasts for more than 12 months.

Cornea ; Humans ; Keratomileusis, Laser In Situ ; Matrix Metalloproteinase 9 ; chemistry ; Myopia ; surgery ; Postoperative Period ; Prospective Studies ; Tears ; chemistry ; Wound Healing