AGT and diabetic macular edema: This study has suggested that arterial hypertension history was a independent risk factor for DR, it was the same with Australia [21], which would be because that hypertension was a risk factor for DR [22] and many diabetic always had hypotension, the renin-angiotensin system was activated by chronic hyperglycemia, and then the vitreous fluid level of angiotensin II (AII) was elevated in patients with PDR and diabetic macular edema.