Overview

Retinal vein occlusion is a common cause of sudden, painless reduction, or loss of vision in older people. It's uncommon in people under the age of 60.

It happens when an artery presses on, and blocks, a vein in the retina (the thin lining at the back of the eye that allows us to see). The retina is similar to a camera film. Blockage of one of these veins causes blood and other fluids to leak into the retina, causing bruising and swelling, as well as starving the retina of oxygen. This can interfere with the cells that detect light, and reduce vision.

Retinal vein occlusions can be permanent. Some people respond well to treatment, but can still have some reduction in vision after treatment.

Types of retinal vein occlusion

There are 2 types of retinal vein occlusion. 

Branch retinal vein occlusion (BRVO)

BRVOs are due to blockage of 1 of the 4 retinal veins, each draining blood from 1/4 of the retina.

Central retinal vein occlusion (CRVO)

CRVO is due to obstruction of the main retinal vein which is formed by the 4 branches. Loss of vision is generally more severe if the central retinal vein is affected.  

Causes of retinal vein occlusion

The cause of retinal vein occlusion is unknown, but there are some common conditions that increase the risk of developing the condition. These include:

• high blood pressure
• high cholesterol
• glaucoma
• diabetes 
• smoking 
• some rare blood disorders 

Treatment options

Identification and treatment of any risk factors is very important to make sure that further vein occlusion does not happen in the same, or the other, eye. 

Persistent swelling (oedema) at the centre of the retina is the main cause of visual loss.

Sometimes laser treatment helps to restore some central vision. If the eye doctor suggests this, it's generally done about 3 months after the vein occlusion has happened.

Your eye doctor might suggest a corticosteroid implant into the eye, known as dexamethasone intravitreal implant (Ozurdex®). This medicine helps to ease any swelling at the central part of the retina, and so improves vision. Ozurdex is not suitable for all patients, but the doctor treating you will tell you if this is something that you are likely to benefit from.

There are other medicines that might be helpful if Ozurdex is not suitable for you. These include medicines that have to be injected directly into the eye, known as aflibercept (Eyelea®) and ranibizumab (Lucentis®) These will be discussed in more detail if the doctor thinks they could work for you.

There is a chance that the blood supply in the eye can be permanently affected if the central vein is blocked. This can lead to abnormal blood vessels growing, which might need further treatments.

What you can do to help yourself

If you have been identified as having any of the following risk factors, you might benefit from treatment for them.

High blood pressure 

If consistently high readings are recorded, treatment is usually recommended

High cholesterol

If you have slightly raised cholesterol, you might want to discuss changes to your diet with your GP, or they might suggest taking tablets called statins.

Glaucoma

This is a relatively common eye condition caused by high eye pressure. Treatment with eye drops to lower the pressure is highly effective at preserving your sight and reducing the risk of further vein occlusions.

Diabetes

Diagnosis and good control of diabetes is essential to preserve your vision. Diabetes can affect your vision in other ways, including diabetic retinopathy (damage to the retina caused by diabetes), and double vision. 

Smoking

The more you smoke, the greater the risk of developing another vein occlusion. If you would like help to stop smoking, please speak to your eye doctor who can refer you to our stop smoking service, or you can contact them directly. 

Various rare blood disorders

These are often identified by simple blood tests. If they need treatment, you will be supervised by a specialist in blood disorders.

Follow-up appointments

If you have BRVO, your follow-up appointments will take place every 4 to 6 months for about 18 months. After that, your symptoms are less likely to get worse. 

If you have CRVO, you will have follow-up appointments every 6 to 8 weeks for the first 6 months. After that, the appointments may be less frequent. Most patients are discharged after 2 years.

Support and more information

The Royal College of Ophthalmologists is a charity that offers information for patients on different eye conditions.

www.rcophth.ac.uk

The Royal National Institute of Blind People (RNIB) is a charity offering information, and support groups for people with sight loss.

www.rnib.org.uk