Correlations of long-term matrix metalloproteinase localization in human corneas after successful laser-assisted in situ keratomileusis with minor complications at the flap margin.

OBJECTIVE: To determine whether matrix metalloproteinases (MMPs) are present long-term in human corneas after successful laser-assisted in situ keratomileusis (LASIK).
METHODS: Eighteen postmortem corneas from 10 patients with postoperative intervals of 2 to 8 years after LASIK surgery and 4 normal control corneas from 2 patients were collected from US eye banks and processed for histologic analysis and immunolocalization with antibodies to MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-10, and MMP-14.
RESULTS: Matrix metalloproteinase 7 was present in the epithelium of all corneas. Other MMPs were localized to the wound margin in some post-LASIK corneas. Matrix metalloproteinase 9 was detected around epithelial cells trapped in the lamellar scar in 5 of 6 corneas with epithelial ingrowth. Various MMPs were detected in fibrotic tissue at the wound margin in 2 of 2 corneas with flap retraction.
CONCLUSIONS: The presence of MMPs in post-LASIK corneas correlates with an ongoing wound healing process associated with minor post-LASIK complications. Matrix metalloproteinases might contribute to instances of ongoing flap instability, and if so, judicious use of MMP inhibitors could provide benefit.