Matrix metalloproteinses(MMPs)are a pivotal family of metal enzymes responsible for degradation of the extracellular matrix(ECM)components during celI migration,tissue remodeling and repairing processes,et al.The potent proteolytic activities of MMPs are mainly regulated by the balance with specific tissue inhibitors of MMPs(TIMPs).MMPs and TIMPs keep on relative balance and mutual influence in tissue,which decides whether the extracellular matrix(ECM) is degradation or aggregation.ECM not only supports the growth and proliferation of lens epithelial cells(LECs),but also promotes LECs proliferation,migration and adhesion and finally leads to posterior capsule opacification and fibrosis.