What is Retinal Artery Occlusion (RAO)?
A retinal artery occlusion (RAO) occurs when one of the retinal arteries that carries oxygen to the nerve cells in the retina becomes blocked. This lack of oxygen can lead to severe vision loss.
At Retina Consultants of Houston, our board-certified ophthalmologist specialize in the diagnosis and treatment of a full range of retinal conditions, including retinal artery occlusions.
Types of Retinal Artery Occlusion
There are two different types of retinal vein occlusion (RVO):
- Central Retinal Artery Occlusion (CRAO): Central retinal artery occlusion (CRAO) occurs when the main artery that supplies blood to the eye (called the ophthalmic artery) becomes blocked.
- Branch Retinal Artery Occlusion (BRAO): Branch retinal artery occlusion (BRAO) occurs when one of the smaller retinal arteries becomes blocked.
Causes and Symptoms of Retinal Artery Occlusion
Retinal artery occlusion typically affects patients over the age of 60 and can be caused by a blood clot or an embolus (a small piece of cholesterol).
The primary symptom of retinal artery occlusion is sudden, painless loss of vision in one eye. In CRAO, this can be a severe vision loss. With BRAO, patients may only lose vision in one part of their visual field (one side for example), or if small enough, may not experience any symptoms at all.
Common risk factors for retinal artery occlusion include:
- High blood pressure
- Carotid artery disease
- Poorly controlled cholesterol
- Blood-clotting disorders like sickle cell disease
Your retina specialist can typically diagnose CRAO or BRAO through a comprehensive dilated eye exam. Your doctor may also use ocular coherence tomography (OCT) and fluorescein angiography to assist with your specific diagnosis and treatment plan.
Treatment and Prognosis
Unfortunately, there are no clinically proven treatments for retinal artery occlusion. If caught very early, your retina physician may try to lower your eye pressure through drops or a procedure called paracentesis (removal of fluid from the front of the eye).Other treatments for rare complications of CRAO or BRAO, such as formation of new blood vessels, include:
- Intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) medications (Lucentis, Avastin, Eylea) or steroids
- Laser therapy
If you have retinal artery occlusion, it is important to see your primary care physician to identify and lower your risk factors that may lead to other vascular conditions like stroke and heart disease.