MMP2 and cataract: At present, the research on the relationship between MMP-2 and cataract has become a hot spot, and especially at the gene level, the conclusions about MMP-2 gene polymorphism and cataract susceptibility are not consistent.[23] The purpose of this study is to explore the relationship between MMP-2 gene polymorphism and cataract susceptibility through meta-analysis, thus providing a new direction for early prevention and treatment of cataract.