Retinal Vein Occlusion and Macular Oedema

What Is Retinal Vein Occlusion (RVO)?

Our eyes are made of lots of big and small blood vessels, the mains ones being where the blood reaches through a main artery supplying oxygen to the retina and leaving through a main vein, draining the de-oxygenated blood.

RVO occurs when the main vein or one of the small branches becomes blocked. As a result, blood and fluid can start to leak which may cause a sudden loss of vision. RVO also compromises the blood flow and the amount of oxygen reaching the eye which can cause the growth of abnormal blood vessels and affect the function of the macula- this is the portion of the retina responsible for central vision.

Types Of Retinal Vein Occlusion (RVO)

Branch Retinal Vein Occlusion (BRVO): Obstruction of a branch of retinal vein(s) which drain specific areas of the retina.

Central Retinal Vein Occlusion (CRVO): Obstruction of the main vein formed from the four branches which drain blood from the retina.

What Causes Retinal Vein Occlusion (RVO)?

It is not always known; however, blood tests and blood pressure checks may be requested to identify the cause. Various contributing factors include:

High blood pressure


Raised cholesterol levels



What Is Macular Oedema (MO)?

Macular Oedema (MO) is the accumulation of fluid in the macula.

The macula is the part of the retina which gives you sharp, straight-ahead vision, e.g. watching television or recognising faces, and being able to see finer detail vision.

Macular oedema is usually caused by abnormal leakage from damaged blood vessels. The accumulation of fluid causes the macula to swell which blurs and distorts vision. Grey shadowed areas are formed where the oedema is present due to Central Retinal Vein Occlusion.

The grey shadowed areas are where Oedema is present due to Central Retinal Vein Occlusion

How Is Retinal Vein Occlusion Diagnosed?

There are a number of diagnostic tests that need to be conducted. Please refer to the Technology heading to find out more about our state of the art equipment.

To investigate and evaluate the integrity of the retina after a vein occlusion has occurred it is best to carry out the Optos® Ultra-Widefield Retinal Scan, Swept-Source DRI Topcon Triton® OCT Angiography Scan, Swept-Source DRI Topcon Triton® OCT Scan, Canon Xephilio® S1 Widefield Swept Source Optical Coherence Tomography (SS-OCT)

Optos® Ultra-Widefield Retinal Scan

This diagnostic test allows for the assessment of blood flow from the central to the far periphery of the retina. Standard retinal cameras cannot capture detailed images of the peripheral retina. There is the need for an injection of dye in the vein of your arm. No radiation is used. These broad views of the retinal enable earlier diagnosis and tailored treatment planning and management of your condition.

Swept-Source DRI Topcon Triton® OCT Angiography Scan

This is a new OCT test which allows for the assessment of retinal blood flow in the central part of the retina in a non-invasive manner without the need of an injection of dye in the vein of your arm. This is an important diagnostic test for the early diagnosis of a change in or loss of blood supply.

Swept-Source DRI Topcon Triton® OCT Scan

This new and advanced optical coherence tomography (OCT) imaging technology allows for improved identification of layers within the retina.

This technology enables Prof. Stanga to identify oedema (fluid) within or under the retina; objectively maps and measures retinal thickness, guides diagnosis and treatment, and monitors response.

How Is Retinal Vein Occlusion Treated?

Once all diagnostic tests have been completed Prof Stanga will discuss with you a tailored treatment plan. This could include a combination of therapy such as Anti-VegF intravitreal injections, steroid injections, and Pascal laser to prevent abnormal vessel growth. You can find more information on these types of treatments under the treatment options on this website.

Treatment is tailored based on the stage of disease and may include one or more of the following: anti-VEGF, steroid injections, and Pascal® laser.

Laser treatment can be applied to either a localised area or the entire retina with the exception of the macula, or both.

Ensuring your blood pressure and cholesterol levels are well-controlled is an essential part of achieving an effective treatment and outcome.