Compared with the control group, the protein expression levels of p-p38MAPK, MMP1 and MMP13 in the model group were significantly increased (p < 0.001), while the protein expression levels of p-p38MAPK, MMP1 and MMP13 in the BCM group and GH group were significantly lower than those in the model group (p < 0.001). Here, MMP13 is linked to blue cone monochromacy.