Studies have shown that the manganese superoxide dismutase (MnSOD) mimetic MnTBAP effectively prevented mitochondrial damage by reducing DNMT1 binding to the MMP-9 promoter (Kowluru and Shan, 2017), suggesting that targeting DNA methylation to inhibit MMP-9 could suppress oxidative stress and serve as a promising therapeutic strategy for diabetic retinopathy. This evidence concerns the gene MMP9 and diabetic retinopathy.