Retinal Artery Occlusion
What are Retinal Artery Occlusions?
A Retinal Artery Occlusion is a blockage or obstruction of the arteries in the retina. This is like a stroke in the eye. The retina is the light-sensitive layer of tissue that lines the back wall of the eye and is responsible for vision. There are two types of retinal vein occlusions:
- Central Retinal Artery Occlusions (CRAO) occur when the main retinal artery is blocked, causing the blood flow to be reduced to the entire retina. This can cause a marked decrease in vision with bleeding, as well as pain with an increase in eye pressure.
- Branch Retinal Artery Occlusions (BRAO) occur when a branch of the main retinal artery becomes obstructed. Blood flow is reduced in a portion of the retina. The amount of vision loss is usually not as severe as in CRAO. Vision loss may be due to bleeding or swelling in the eye.
What are the Symptoms?
Decreased vision is the most common symptom. Other symptoms include floaters or spots in the vision. In severe cases, eye pain can occur as a result of increased eye pressure. Severe cases also can result in vision loss, permanent damage to the eye, and even loss of the eye.
What causes Retinal Vein Occlusions?
A Retinal Artery Occlusion is often an indication of vascular (blood vessel) problems in the rest of your body. Additional medical evaluation may need to be done by your primary care doctor. Sometimes, the source of a Retinal Artery Occlusion cannot be identified, despite testing. The most common risk factors that may contribute to Retinal Artery Occlusion include carotid artery disease (blood vessels in the neck), heart disease, high blood pressure, diabetes, atherosclerosis and blood disorders.
How is a Retinal Vein Occlusion Detected?
Your eye doctor will use eye drops to dilate, or enlarge your pupils. Dilating the pupils allows your eye doctor to view the back of the eye better. You may need testing, including a fluorescein angiography. Fluorescein angiography is a test that uses a diagnostic agent called fluorescein that is injected into a vein in your arm. It is used to enhance the specialized photograph that is taken to evaluate the retina.
What are the Treatment Options?
There is no known cure for a Retinal Artery Occlusion. Laser treatment may help improve sight in some patients. Laser treatment is a high energy beam of light used to seal leaking blood vessels in the hope of reducing swelling and bleeding in the macula, which is the central part of the retina needed for reading, driving, and seeing fine detail.
In some patients with a retinal atery occlusion your eye may form abnormal new blood vessels (neovascularization). These abnormal blood vessels may cause severe bleeding or a severe form of glaucoma. If your eye develops these new abnormal blood vessels laser may need to be done to get rid of these blood vessels. The laser will probably not improve the vision but with out the laser further pain or vision loss will probably occur. Laser treatment is performed on an outpatient basis in the eye doctor’s office.