Retinal Vein and Artery Occlusion

Download a pamphlet on RVO in English

Download a pamphlet on RVO in Spanish

What is a retinal vein occlusion?

A retinal vein occlusion (RVO) occurs when one of the retinal veins becomes blocked. 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.


A blocked retinal vein damages the retinal blood vessels and can lead to hemorrhage (bleeding), impaired blood flow, leakage of fluid and blood components (hard exudates) into the retina. RVO can cause visual impairment in four ways:

  • Blood and hard exudates can directly interfere with retinal function.

  • Abnormal fluid can accumulate in the retina, leading to thickening and the presence of cyst-like fluid collections that distort normal retinal architecture. This is called cystoid macular edema (CME).

  • Inadequate blood flow to the retina, which is called ischemia.

  • 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).

Who is at risk for a retinal vein occlusion?

Diabetes, high blood pressure, poorly controlled cholesterol and smoking can all increase a patient’s risk of RVO. Many other conditions can cause RVO also including glaucoma, inflammation and hypercoaguable states. Depending on your clinical situation you may need to be evaluated for these less common conditions.

Disease Course & Treatment

The most common symptoms of RVO are blurred and distorted central vision. Other symptoms may include dim vision or decreased sensitivity to light. Sometimes patients may have no symptoms. Your ophthalmologist may obtain multiple types of ocular imaging, including photography, ocular coherence tomography (OCT) and angiography to facilitate diagnosis and treatment. Depending on the cause and severity of a RVO, ocular treatment may include the following: close clinical observation, intravitreal injections of anti-vascular endothelial growth factor medications (Lucentis, Avastin, Eylea) or steroids, laser therapy and/or vitrectomy surgery.

In addition to specific ocular treatments, it is very important that a patient with RVO work with their primary care physician to optimally control their cardiovascular risk factors including diabetes, blood pressure, cholesterol and weight.