All these changes impair vision and require urgent treatment. The goal of treatment is to lower the high blood pressure that's the root of the problem. When the high blood pressure is severe and life threatening, treatment may be needed immediately to save vision and avoid other complications. The retinal artery is the main vessel supplying blood to the retina. If it's blocked, the affected eye is suddenly but painlessly blinded.
Immediate treatment is needed to preserve vision.
The retinal vein is the main vessel carrying blood from the retina. Blockage of it causes the smaller veins in the retina to become swollen and tortuous. The surface of the retina becomes congested and swollen, and blood may leak into the retina. Retinal vein blockage occurs mainly in elderly people with glaucoma, diabetes, high blood pressure, or conditions that thicken the blood, such as an abnormally high number of red blood cells. Retinal vein blockage causes a painless loss of vision that develops much more slowly than it does in retinal artery blockage.