by Scholten A
(RVO, Branch Retinal Vein Occlusion, BRVO, Central Retinal Vein Occlusion, CRVO) 


Retinal vein occlusion (RVO) is when a vein (blood vessel) in the retina is blocked. The retina is tissue in the back of the eye. In RVO, the vein blockage leads to a buildup of pressure in the retina. It can lead to lasting vision problems.

There are two types of RVO:

Central (CRVO)—the main vein is blocked

Branch (BRVO)—one of the smaller veins is blocked


RVO is often caused by a blood clot that blocks a vein in the retina. It slows the flow of blood out of the retina. Blood backs up in the retina and increases pressure. Blood or fluid may then leak out of blood vessels into the eye. Sometimes new blood vessels form. The leaking blood and fluid and new blood vessels can cause a loss of vision.

Risk Factors

RVO is most common in adults over 40 years old. Other things that raise the risk are:

  • High blood pressure
  • High cholesterol and atherosclerosis
  • Diabetes
  • Certain eye problems, such as high eye pressure and glaucoma
  • Smoking
  • Birth control pills
  • Conditions that cause inflammation of the blood vessels, such as:
    • Vasculitis
    • Systemic lupus erythematosus (SLE)
  • Sleep apnea


RVO does not always cause symptoms. It may occur in one or both eyes. When symptoms happen, they can be sudden and may be:

  • A blind spot in the middle of a person’s vision
  • Blurred eyesight
  • Straight lines (such as door frames) appear round or curvy
  • Small shapes float across a person’s vision

Symptoms may occur in one or both eyes. RVO does not usually cause pain.


RVO may be found during a routine eye exam. The exam will check vision and look for leaking, swelling, and abnormal blood vessels in the retina.

Tests may be done to better see the retina. They may include:

  • Color and red-free fundus photography
  • Ocular coherence tomography (OCT)
  • OCT angiography
  • Fluorescin angiography
  • Ocular ultrasonography

The eye exam and tests will confirm the diagnosis.


The blockage cannot be treated. The goal of treatment is to improve vision or keep it from getting worse. It can take about a year to know what vision changes may happen.

Treatment can help to decrease swelling from fluid build up, called edema. This will slow or stop leaking and new blood vessel growth. Other treatment can stop new blood vessels growth. Options may be:

  • Medicines given by injection into the eye, such as:
    • Anti-endothelial growth factor (anti-VEGF) agents—to reduce leakage and prevent abnormal blood vessels from growing in the eye
    • Corticosteroids—to reduce swelling
  • Procedures, such as:
    • Focal laser therapy—may be used with anti-VEGF agents
    • Laser photocoagulation treatment—to stop abnormal blood vessels from growing in the eye

Regular follow up appointments will track changes. Treatment for related health issues like high blood pressure will also be needed.


The risk of RVO may be reduced by treating high blood pressure, high cholesterol, and diabetes.


American Academy of Ophthalmology  

American Society of Retina Specialists 


Canadian Retina Society  

Canadian Ophthalmological Society  


Branch retinal vein occlusion. American Society of Retina Specialists website. Available at: . Accessed March 27, 2021.

Flaxel CJ, Adelman RA, et al. Retinal vein occlusions preferred practice pattern. Ophthalmology. 2020;127(2):P288-P320.

Retinal vein occlusion. EBSCO DynaMed website. Available at: . Accessed March 27, 2021.

What is branch retinal vein occlusion (BRVO)? American Academy of Ophthalmology website. Available at: Accessed March 27, 2021.

Revision Information

  • Reviewer: EBSCO Medical Review Board Nicole Meregian, PA
  • Review Date: 09/2021
  • Update Date: 09/22/2021