WHAT IS A RETINAL ARTERY OCCLUSION?
Arteries bring blood into the eye and veins take blood from the eye to the heart. A retinal artery occlusion happens when you have a blockage of either the main artery of the retina or one of its branches. It is considered a stroke of the retina and is usually unilateral, acute and painless. Patients usually have a history of some transient visual changes. The occlusion and change in vision happens within seconds and can permanently damage the retinal tissue if it lasts 60 to 90 minutes.
WHAT ARE THE RISK FACTORS FOR A RETINAL ARTERY OCCLUSION?
Certain diseases can cause a retinal artery occlusion. First and foremost, your physician will rule out a blinding disease that is secondary to inflammation of the arterial blood vessel walls, that is called Giant Cell Arteritis. Most retinal artery occlusions are secondary to an embolus secondary to cholesterol, calcium or platelet-fibrin breaking off from a plaque in the neck or heart.
The main risk factors for a retinal artery occlusion are: high blood pressure, diabetes, cholesterol, heart valve abnormalities, collagen vascular diseases, blood clotting diseases, giant cell arteritis.
WHAT IS THE WORK-UP FOR A RETINAL ARTERY OCCLUSION?
A full history at the time of diagnosis of a retinal artery occlusion is critical to rule out any signs of a blinding disease called Giant Cell Arteritis which would require emergent treatment with steroid in order to prevent a blinding arterial occlusion in the other eye. A full work-up includes blood pressure evaluation, blood tests to rule out giant cell arteritis, blood clotting diseases, an ultrasound of the neck and a cardiac ECHO. Other tests are also included by your doctor depending on your presentation.
WHAT ARE THE TREATMENTS FOR A CENTRAL RETINAL ARTERY OCCLUSION?
Central retinal artery occlusions (CRAO) are evaluated with a dilated examination of the retina and with a retinal angiogram to look at how much blood is reaching the retina. A CRAO can lead to swelling of the retina which can be treated by administering medications that counteract the high abnormal levels of certain factors present within the eye. The majority of CRAO cases regain peripheral vision however central vision is usually significantly affected.