What You Should Know About Retinal Occlusions
When a blockage (also known as occlusion) occurs in one of the retinal blood vessels, it can be a critical health concern. Retinal tissue relies on blood vessels to continually deliver oxygen-rich blood, and remove waste products. Retinal occlusions can cause blood and fluid to leak into the retinal tissue. Regular ophthalmic monitoring is essential, as these occlusions can be medical emergencies.
Types of Retinal Occlusions
There are different types of retinal occlusions named according to their location within the retina and whether they affect a vein or an artery.
Central Retinal Artery Occlusion (CRAO)
Central retinal artery occlusion (CRAO), also known as an eye stroke, develops in the retina’s main artery. CRAO may cut off the retina’s supply of oxygen-rich blood. The most common symptom of CRAO is sudden, painless vision loss. Other symptoms may include blind spots, visual distortions, and permanent loss of peripheral (side) vision.
Branch Retinal Artery Occlusion (BRAO)
Branch retinal artery occlusion (BRAO) is a blockage that develops in a branch extending from the central retinal artery. This can cause the macula’s blood supply to be cut off.
Central Retinal Vein Occlusion (CRVO)
A blockage affecting the main retinal vein is called a central retinal vein occlusion (CRVO). There are two types of CRVO:
- Nonischemic – a mild form of CRVO causing retinal blood vessels to leak
- Ischemic – a severe type of CRVO that limits or blocks blood flow
When retinal vein occlusions progress, they can cause structural damage to the veins, resulting in bleeding and loss of blood flow. To compensate, your eyes may develop new, fragile blood vessels, in a process called neovascularization. Once neovascularization occurs there is a risk of bleeding, leaking, and eye floater development.
Branch Retinal Vein Occlusion (BRVO)
A branch retinal vein occlusion (BRVO) is when a small vein branching off from the central retinal vein becomes blocked. While there may be no symptoms, you may experience floaters, peripheral vision loss, and central vision distortions or blurriness. There may also be bleeding in the vitreous.
Retinal Occlusion Risk Factors
Retinal artery and vein occlusions generally occur in people in their 60s and happen more often in men. Common risk factors include:
- Aging
- Smoking
- Diabetes
- High cholesterol
- Glaucoma
- Being overweight
- Uncontrolled hypertension (high blood pressure)
- Atherosclerosis
- Cardiovascular (heart) disease
- Glaucoma
- Abnormal blood clotting factors (usually occurs in younger adults)
Macular Edema
Significant retinal leakage may lead to a complication called macular edema involving irregular swelling and fluid accumulation in the macula. If left untreated permanent vision loss may result. Fortunately, in many cases retina treatments are available to limit and even reverse damage from macular edema.
Retinal Occlusion Prognosis
There is no cure for retinal occlusion, therefore your retina specialist will recommend regular monitoring and treatment if appropriate. Related underlying conditions and risk factors, such as high blood pressure, should be properly managed. Without proper treatment and regular intervention, retinal occlusion may result in irreversible vision loss.
Retinal artery occlusions are medical emergencies because they can often be a harbinger of an impending cerebral vascular accident (i.e., stroke). Patients with new BRAOs and CRAOs should be referred emergently to the hospital to be evaluated for stroke.
Learn More About Retinal Occlusions
A retinal artery or vein occlusion may pose a significant health threat, impacting retinal function. Regular ophthalmic exams are essential to identify occlusions, continually monitor your disease progress, and formulate a plan of care as needed. To schedule a consultation we invite you to contact us at Retinal Consultants Medical Group today for an appointment.
