Figure 6. Expression of MMP-2 at the central part of lenticules at 48 h and 4 weeks. There was minimal expression of matrix metalloproteinase (MMP)-2 in groups 4 and 6–8, and the expression was not detectable in the other groups. Negative control ((-) C): fresh lenticules; positive control ((+) C): primary human stromal fibroblasts. Nuclei were counterstained with 4',6-diamidino-2-phenylindole dihydrochloride (DAPI; blue). Original magnification: 200X; scale bar = 50 μm.