Due to the significant role played by vascular endothelial growth factor A (VEGF) in endothelial cell dysfunction, intravitreal injection (IVI) of its neutralizing antibody has been widely used to treat diabetic macular edema (DME) (Nguyen et al, 2009; Diabetic Retinopathy Clinical Research et al, 2015) and proliferative diabetic retinopathy (PDR) (Sivaprasad et al, 2017) in clinical practice. Here, VEGFA is linked to diabetic macular edema.