Skip to content

Magdalena G. Krzystolik, M.D. - Paul B. Greenberg, M.D.

Expert retinal care for Rhode Island and Southern Massachusetts

Retinal Vein and Retinal Artery Occlusion - Retinal diseases and treatments

Retinal Vein and Retinal Artery Occlusion

You probably know that high blood pressure and other vascular diseases pose risks to overall health, but you may not know that they can affect eyesight by damaging the veins in the eye. There are several vascular retinal conditions that may develop: central retinal vein occlusion, branch retinal vein occlusion, central retinal artery occlusion, and branch retinal artery occlusion.

CRVOCentral retinal vein occlusion (CRVO) blocks the main vein in the retina, the light-sensitive nerve layer at the back of the eye. The blockage causes the walls of the vein to leak blood and excess fluid into the retina. When this fluid collects in the macula (the area of the retina responsible for central vision), vision becomes blurry.

"Floaters" in your vision are another symptom of CRVO. When retinal blood vessels are not working properly, the retina grows new fragile vessels that can bleed into the vitreous, the fluid that fills the center of the eye. Blood in the vitreous clumps and is seen as tiny dark spots, or floaters, in the field of vision.

In severe cases of CRVO, the blocked vein causes painful pressure in the eye. Retinal vein occlusions commonly occur with glaucoma, diabetes, age-related vascular disease, high blood pressure, and blood disorders.

The first step of treatment is finding what is causing the vein blockage. There is no cure for CRVO. Your ophthalmologist (Eye M.D.) may recommend a period of observation, since hemorrhages and excess fluid often subside on their own. Laser surgery may be effective in preventing further bleeding into the vitreous or for treating glaucoma, but it cannot remove a hemorrhage or cure glaucoma once it is present. Occasionally intravitreal injections of medications into the way may be used as treatment. New experimental treatments are now under investigation.

Branch retinal vein occlusion (BRVO) blocks small veins in the retina, the layer of light-sensing cells at the back of the eye. If the blocked retinal veins are ones that nourish the macula, the part of the retina responsible for straight-ahead vision, some central vision is lost. During the course of vein occlusion, 60% or more will have swelling of the central macular area. In about one-third of people, this macular edema will last for more than one year.

BRVO causes a painless decrease in vision, resulting in misty or distorted vision. If the veins cover a large area, new abnormal vessels may grow on the retinal surface, which can bleed into the eye and cause blurred vision.

There is no cure for BRVO. Finding out what caused the blockage is the first step in treatment. Your ophthalmologist (Eye M.D.) may recommend a period of observation, since hemorrhages and excess fluid may subside on their own. Depending on how damaged the veins are, laser surgery may help reduce the swelling and improve vision. Laser surgery may also shrink abnormal new blood vessels that can grow and that are at risk of bleeding. Newer injectable medicines are being investigated for treating BRVO.

CRAOCentral retinal artery occlusion (CRAO) usually occurs in people between the ages of 50 and 70. The most common medical problem associated with CRAO is arteriosclerosis (hardening of the arteries). Carotid artery disease is found in almost half the people with CRAO.

The most common cause of CRAO is a thrombosis (an abnormal blood clot formation). CRAO can also be caused by an embolus, a clot that breaks off from another area of the body and is carried to the retina by the bloodstream.

CRAO blocks the central artery in your retina, the light-sensitive nerve layer at the back of the eye. The first sign of CRAO is a sudden and painless loss of vision that leaves you barely able to count fingers or determine light from dark.

Loss of vision can be permanent without immediate treatment. Irreversible retinal damage occurs after 90 minutes, but even 24 hours after symptoms begin, vision can still be saved. The goal of emergency treatment is to restore retinal blood flow. After emergency treatment, you should have a thorough medical evaluation.

Branch retinal artery occlusion (BRAO) blocks the small arteries in the retina, the light-sensing nerve layer lining the back of the eye. The most common cause of BRAO is a thrombosis, the formation of a blood clot. Sometimes the blockage is caused by an embolus, a clot carried by the blood from another part of the body.

Central vision is lost suddenly if the blocked retinal artery is one that nourishes the macula, the part of the retina responsible for fine, sharp vision. Following BRAO, vision can range from normal (20/20) to being barely able to detect hand movement.

BRAO poses significant risks to vision. If you have had a branch retinal artery occlusion, regular visits to your ophthalmologist are essential.