Retinal Vein / Artery Occlusions

When performing a comprehensive, dilated eye examination, Dr. Jiménez and the other ophthalmologists at Southern Eye Center, can directly see your retinal blood vessels in the back of your eyes. The appearance of these vessels and your retina are excellent markers of the overall health of your body’s vascular system. In fact, the retina is the only place in the body where your eye physician can directly view your blood vessels.

Hypertension & Your Eyes

Your retina is one of the organs most sensitive to sustained hypertension (elevated blood pressure). Prolonged elevated blood pressure may lead to changes to your retina, including:

  • Bleeding
  • Edema and swelling of your retina
  • Exudative changes (fluid leakage) and buildup of protein and lipids in the retina
  • Small infarcts of the retina (tissue death due to an inadequate blood supply), also known as “cotton wool spots”
  • Arteriosclerosis: arteriolar narrowing, artery-vein crossing changes (also known as “AV nicking”), changes in the color of arterioles and in advanced cases, sclerosis (abnormal hardening) of the blood vessels
  • Optic nerve swelling and blurred vision

Severe cases of hypertension may result in blockages of the retinal veins or arteries. These blockages of circulation (known as “occlusions”), may lead to severe loss of vision or even blindness. There are two types of retinal occlusions: retinal artery occlusions and retinal vein occlusions.

Retinal Artery Occlusions

A retinal artery occlusion (RAO) occurs exists 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.

There are two different types of RAO:

  • Central retinal artery occlusion (CRAO) occurs when the main artery that supplies blood to the eye (called known as the ophthalmic artery) becomes blocked.
  • Branch retinal artery occlusion (BRAO) occurs when one of the smaller retinal arteries becomes blocked.

Dr. Jiménez, our board-certified ophthalmologist, fellowship trained in medical and surgical retina care, specializes in the diagnosis and treatment of a full range of retinal conditions, including retinal artery occlusions.

Causes and Symptoms of RAO

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 result in a severe vision loss. With BRAO, patients may only lose vision in one part of their visual field (one side or one quadrant, for example) or, if small enough, the patient may not perceive any visual loss that may have taken place.

Common risk factors for retinal artery occlusion include:

  • Diabetes
  • High blood pressure
  • Carotid artery disease
  • Atherosclerosis
  • Inadequately controlled cholesterol
  • Blood-clotting disorders like such as sickle cell disease
  • Smoking

Diagnosing RAO

Dr. Jiménez can typically diagnose CRAO or BRAO at the time that he performs a comprehensive, dilated eye examination. Depending upon his findings, Dr. Jiménez may also use ocular coherence tomography (OCT), fluorescein angiography, specialized retinal photography or other diagnostic testing to assist with your personal specific diagnosis and treatment plan.

Treatment for RAO

Unfortunately, there are no clinically proven treatments for retinal artery occlusion. If caught very early, Dr. Jiménez may try to lower your eye pressure via eye drop medications or a procedure called a paracentesis, where he removes a small amount of fluid from the forward part of the affected 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 and 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 such as stroke and heart disease.

Retinal Vein Occlusions

A retinal vein occlusion (RVO) occurs when one of the veins that drains blood from the retina in the back of your eye becomes blocked. A blocked retinal vein damages the retinal blood vessels and can lead to hemorrhage (bleeding), impaired blood flow, and leakage of fluid and blood components (hard exudates) into the retina. RVO can cause visual impairment in four ways:

  1. Blood and hard exudates can directly interfere with retinal function.
  2. Abnormal fluid can accumulate in the retina, leading to thickening and the presence of cyst-like fluid collections that distort the normal retinal appearance. This condition is known as cystoid macular edema (CME).
  3. Inadequate blood flow to the retina, referred to as ischemia.
  4. Abnormal blood vessels can grow from the surface of the retina. This is called neovascularization. These fragile blood vessels can bleed and form damaging scar tissue. Sometimes, these abnormal blood vessels can grow on the iris and drainage canals in the eye, leading to increased eye pressure (neovascular glaucoma).

There are two different types of RVO:

  • Central retinal vein occlusion (CRVO) occurs when the main vein that drains the retina becomes blocked.
  • Branch retinal vein occlusion (BRVO) occurs when one of the smaller retinal veins becomes blocked.

Dr. Jiménez, our board-certified ophthalmologist, fellowship trained in the medical and surgical treatment of retinal conditions is highly experienced in the diagnosis and treatment of retinal vein occlusions.

Causes and Symptoms of RVO

Diabetes, high blood pressure, elevated cholesterol and smoking can all increase a patient’s risk of RVO. Many other conditions can cause RVO, including glaucoma, inflammation and blood clotting disorders. Evaluation for these other conditions is typically part of a patient’s treatment.

The most common symptoms of RVO include:

  • Blurred, distorted central vision
  • Vision that appears “dim”
  • Decreased light sensitivity

Sometimes, however, patients with CRVO or BRVO experience no perceivable symptoms.

Diagnosing RVO

Dr. Jiménez may obtain images of your eye by different types of technology, including photography, ocular coherence tomography (OCT) and fluorescein angiography to help with your diagnosis and treatment.

Treatment for RVO

Unfortunately, there are no clinically proven treatments for retinal artery occlusion. If caught very early, Dr. Jiménez may try to lower your eye pressure via eye drop medications or a procedure called a paracentesis, where he removes a small amount of fluid from the forward part of the affected 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 and laser therapy.

Dr. Jiménez works with each his patients to diagnose and create an individualized treatment plan to address retinal vein occlusion. If found early, RVO can be treated so that further blockage of the veins to the retina do not progress and cause further damage.