RETINAL VEIN & ARTERY OCCLUSION

What is a Retinal Vein Occlusion?

A Retinal Vein Occlusion is a blockage of a vein in the retinal circulation that causes retinal bleeding and leakage of fluid into the retina.

Visual loss varies depending on the severity of the blockage.

Who is at Risk of Retinal Vein Occlusion?

Retinal Vein Occlusions are more common in older patients. High blood pressure is the strongest risk factor, but other cardiovascular risk factors such as smoking, high cholesterol and diabetes may contribute. Less commonly other blood disorders need to be considered.

What are the Symptoms of Retinal Vein Occlusion?

Mild cases may have no symptoms and may be picked up incidentally. These may not require treatment particularly if the macula is not involved.

In other cases there may be blurred vision. In the most severe cases the eye can become red, painful and blind.

Types of Retinal Vein Occlusion

There are two main types of Retinal Vein Occlusion:

Central Retinal Vein Occlusion (CRVO)

Central Retinal Vein Occlusion occurs when the major central retinal vein, draining blood from the entire retina, is blocked. This results in poor blood flow throughout the retina and can cause severe loss of vision.

Branch Retinal Vein Occlusion (BRVO)

When a branch of the central retinal vein become blocked, it is called Branch Retinal Vein Occlusion (BRVO).

Visual loss varies but in many cases is not as severe as with a Central Retinal Vein Occlusion.

How is Retinal Vein Occlusion Diagnosed?

An RVO is typically diagnosed by examining the retina after dilating the pupils. Your Ophthalmologist will be able to recognize the characteristic pattern of hemorrhages that occurs in a CRVO or BRVO.

Further tests include Optical Coherence Tomography (OCT) to quantify the degree of macular swelling (macular oedema).

Fluorescein angiography and OCT angiography are useful to identify the degree of underlying damage to the circulation and in some cases to guide laser therapy.

Blood tests may be ordered to help determine the underlying cause of the condition. You may be referred back to your general medical practitioner or a physician for such investigations.