VEGFA and endothelial dysfunction: The pathophysiology behind retinal vessel tortuosity is postulated to be due to the constant inflammatory state in CKD leading to dysregulation of blood flow [35, 36], tissue hypoxia, endothelial dysfunction [37], and increased levels of vascular endothelial growth factor (VEGF) [38] causing vessel wall weaking and fragility, and consequently remodelling occurs.