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Retinal vein occlusion (RVO) is a disease which occurs when the veins in the retina become blocked. There are two types of retinal vein occlusion, Branch Retinal Vein Occlusion (BRVO) and Central Retina Vein Occlusion (CRVO) and these diseases are the second-most-common retinal disorders.

Central Retina Vein Occlusion (CRVO) is the blockage of the main retinal vein whilst Branch Retinal Vein Occlusion (BRVO) is the blockage of a branch retinal vein.


Branch Retinal Vein Occlusion (BRVO)

What are the symptoms?

The main symptom to look out for is visual floaters. The floaters are caused by blood vessels leaking into the eye causing vision loss or blurry vision in part, or all of one eye. It can happen suddenly or be a gradual deterioration but is usually a painless loss of vision. However, retinal vein occlusion often has no symptoms and can sometimes go unnoticed.

Retinal Vein Occlusion.jpg

What are the causes?

  • High blood pressure

  • Diabetes

  • Glaucoma

  • Hardening of the arteries

What are the treatments?

Injections – There are currently several anti-VEGF drugs. These are designed to stop the growth of abnormal blood vessels in the eye and reduce fluid leaking. Local anesthetic is applied via eye drops before the injection is given to numb the eye. This form of treatment may require frequent injections. In more difficult to treat cases the steroid injections are applied to the eye.

Laser Treatment – In more stubborn cases, laser treatment can be applied alongside anti-VEGF injections. This involves applying laser pulses to the macula.


Central Retinal Vein Occlusion (CRVO)

Central Retina Vein Occlusion (CRVO) is the blockage of the main retinal vein When the vein becomes blocked, blood and fluid spill out into the retina affecting your vision. Eventually, nerve cells are starved of oxygen and die, causing your loss of vision to become permanent.

The most common symptom is blurry vision or vision loss in part or all of one eye. It can happen suddenly or become worse over several hours or days. Sometimes, you can lose vision all of a sudden. You may also notice floaters or dark spots affecting your vision.



The main objective is to keep your vision stable and avoid any further deterioration. This is achieved by closing off any leaking blood vessels in the retina. This helps prevent further swelling of the macula.

If the CRVO is not too severe we would look to treat it with anti-VEGF injections. This helps to reduce the swelling of the macula. We can sometimes inject steroid medicine in the eye to help treat the swelling. However, if the symptoms of CRVO are more severe then we may offer laser surgery.

Following treatment, it will take a few months before you notice any improvements in your vision. Whilst most people do see improvements, some won’t due to the severity of the damage already caused to the retina.

“This image was originally published in the Retina Image Bank® website.

Author and Phtographer: James B. Soque, CRA OCT-C COA. Branch Retinal Vein Occlusion- Fluorescein Angiogram, Montage. Retina Image Bank. 2016; 26439. © the American Society of Retina Specialists."

The Annan Retina Eye Center can offer treatment for Retinal Vein Occlusion please schedule a visit with Dr El Annan at the Annan Retina Eye Center. Please call 346-22A-NNAN to speak to a member of staff who will be more than happy to help you

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