Correlation between the matrix metalloproteinase-9 activity and chondroitin sulfate concentrations in tear fluid after laser in situ keratomileusis

Abstract

Tetsuya Mutoh, Masaya Nishio, Yukihiro Matsumoto, Kiyomi Arai Department of Ophthalmology, Dokkyo Medical University Koshigaya Hospital, Koshigaya, Saitama, JapanAims: The aim of the present study was to evaluate the correlation between matrix ­metalloproteinase-9 (MMP-9) and chondroitin sulfate (CS) concentrations in human tear fluid following laser in situ keratomileusis (LASIK).Methods: Twelve eyes from six patients who had no ocular complaints except for ­refractive errors, and who had undergone LASIK, were enrolled in this study. We measured the ­concentrations of chondroitin 4 sulfate (C4S), chondroitin 6 sulfate (C6S), and MMP-9 activity with an enzyme-linked immunosorbent assay and an enzyme immunocapture activity assay preoperatively and postoperatively on days 1 and 4, week 1, and at 1 and 3 months.Results: Although the preoperative MMP-9 activity and the C4S concentration were highly correlated (r = 0.900; P < 0.001), they were not postoperatively correlated at month 1. Although the preoperative MMP-9 activity and the C6S concentration were highly ­correlated (r = 0.885; P < 0.001), they were not postoperatively correlated at either week 1 or months 1 and 3.Conclusions: The correlation appeared to be collapsed by LASIK, and it did not recover to the preoperative score at 3 months post-surgery. Our study indicates that the corneal wound healing was not terminated at 3 months following LASIK.Keywords: preoperative correlation, postoperative correlation, wound healing, refractive errors, human cornea