The staging of hypertensive retinopathy is divided into: I. Grade I retinopathy, which is characterized by mild and insignificant constriction or sclerosis of small retinal arteries; II. Grade II retinopathy, which is characterized by moderate and unremarkable constriction or sclerosis of small retinal arteries, localized narrowing of small arteries, extreme reflex action of small arteries, and localized narrowing of arterioles; III. Grade III retinopathy, which is characterized by hemorrhage, cotton wool spots, hard exudates and microangiomas of the retina; IV. Grade IV retinopathy, which is combined with optic papillary edema on top of grade III retinopathy.