Branch Vein Occlusion

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The reduction in blood flow from a branch vein occlusion causes regional bleeding in the retina seen on the left side of this retina photograph.

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In more severe branch vein occlusions, bleeding may occur from the growth of new abnormal blood vessels into the vitreous cavity in front of the retina.

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What is a Branch Retinal Vein Occlusion?

Branch Retinal Vein Occlusion (BRVO) occurs when blood flow in a vein is reduced or blocked. The point of obstruction is usually where a retinal artery crosses over a vein and pinches it closed, disrupting flow. Sometimes the obstruction is reversible, and sometimes it is irreversible.

Why is my Vision Decreased?

As blood and fluid backs up like a traffic jam, the central part of the retina begins to swell. The tissue of the macula, the most sensitive part of the retina and the part responsible for detailed vision, develops a type of swelling known as macular edema.

What Causes a Branch Retinal Vein Occlusion?

A branch retinal vein occlusion is most likely to occur in people with a history of hypertension, diabetes, glaucoma, ocular inflammation or carotid artery disease. BRVO may also occur in diseases where the blood is too thick. The conditions associated with branch retinal vein occlusion are detected with complete ocular and general examinations, and with laboratory and blood tests. Good control of your diabetes or hypertension, if present, will play an important role in caring for your eye and preventing further damage to your vision.

What are the Symptoms of a Branch Retinal Vein Occlusion?

Most note a sudden blurring or distortion of the vision. Depending on the size and precise location of the blockage, some patients can have a severe blind spot in the center of their vision. Even in the worst cases where there is a permanent loss of blood supply to the critical areas of macula, the side vision always remains intact and there is no pain. 

What Testing Might Be Done?

Your ophthalmologist can diagnose a branch retinal vein occlusion by looking inside your eye with special instruments.  A photographic test called flourescein angiogram and optical coherence tomography scan (OCT) may be done in order to determine the extent of the damage to the macula. 

What About Treatment?

Sometimes vision improves spontaneously, but for many patients persistent macular edema causes most of the vision loss. In these cases, focused laser treatment increases the chances for vision improvement by more than 60%. If there is new blood vessel growth and extensive bleeding results, a broader zone of scattered laser spots reduces the chance of severe visual loss in more than 85%. 

My Doctor Says There is too Much Blood in the Way to Laser. Is there Anything that can be Done?

If blood obscures the ability to perform laser treatment, a medicine can be injected safely into your eye to encourage reduction in macular edema and an improvement in vision. Laser is applied later on to help maintain good vision. Although this is a newer technique, it is widely used across the country by many retina specialists. 

What Should I Expect After Treatment?

Fortunately, many patients can expect to regain good vision–good enough to pass a drivers test. Some will have poor vision due to loss of the delicate blood supply to the highly sensitive macula. On rare occasions, the problem is recurrent or affects the other eye. Your doctor can tell you about your individual prognosis.