Specific blockade of the RAS with the Angiotensin II receptor type 1 (AT1R) blocker (Losartan, Candesartan) and angiotensin-converting enzyme inhibitor (Enalapril) has been shown to reduce the risk of onset and the progression of retinopathy in patients with type 1 and 2 diabetes [44,237,238]. This evidence concerns the gene AGTR1 and retinal disorder.