Diagnosis and treatment

How is retinal vein occlusion diagnosed?

The following procedures are frequently recommended for patients with retinal vein occlusion. Your doctor will explain the reasons for them in more detail with you in person.

Fluorescein angiography

A diagnostic test which involves the injection of fluorescein (yellow) dye into your bloodstream via a vein in your hand or arm. This is followed by a series of retinal photographs taken over several minutes. This test gives your doctor more information about the condition of your retina, which will help decide which treatment is most appropriate for you.

Optical coherence tomography (OCT)

An OCT measures the amount of retinal swelling (macular oedema) which, like fluorescein angiography, helps decide which treatment is most appropriate for you. OCT is also used to monitor your retina over time and can show how effective any treatment may have been. It is effectively ‘optical ultrasound’, a non-invasive test, using reflections from within your retina to provide a cross-sectional picture of the retina.

Effects of retinal vein occlusion and treatment options

One in three patients with central retinal vein occlusion may experience worsening of vision in the first three years.
In retinal vein occlusion, vision is reduced secondary to:

1. Damage to the retina caused by the obstruction to blood flow in the veins. There is no treatment for this.
2. Collection of fluid in the retina (macular oedema). There are several successful treatment options for this, which are described below

Treating fluid in the retina (macular oedema)

Persistent bruising and swelling at the centre of the retina (the macula) is the main cause of permanent loss of central vision. The swelling is caused by damaged blood vessels which leak fluid.

Different medicines such as antivascular endothelial growth factor (antiVEGF) medicines or steroids may be helpful in reducing this leakage. 

Anti-VEGF medicines

Anti-VEGF are given as a fluid injection and need to be given every month until maximum vision is achieved. After that, they may be given on extended intervals, depending on whether they are necessary, until there are no signs of active disease. Treatment is needed for up to four years on average. 

Steroids

Steroids are given in the form of an implant injected into the eye which can be repeated every four to six months as needed, for an average of four years. Injection treatment aims to stabilise or improve vision. About 50% of patients treated with anti-VEGF injections experience a significant gain in vision (a three line improvement on a standard vision chart). Steroid implants achieve a significant gain in vision in up to 50% of patients. However, 20-30% of patients experience no improvement in vision following injection treatment, be it an anti-VEGF or steroid injection.

All injection treatments have potential side effects, including a 1 in 1500 chance of infection, causing decreased vision. Anti-VEGF injections are also associated with increased risk of cardiovascular side effects. Steroid injections may cause side effects such as the formation of a cataract. They also may cause raised eye pressure, which can result in glaucoma. The above options for treating macular oedema have both advantages and disadvantages, which may be more or less suitable for each person with retinal vein occlusion. Your ophthalmologist can discuss this in more detail with you.

Alternatives to treatment

If you would prefer not to have active treatment for macular oedema, observation or monitoring the condition of your eye is always an option. Branch retinal vein occlusions have a better chance of the fluid naturally clearing up than central retinal vein occlusions. However, early active injection treatment of macular oedema has been shown to achieve the best results in terms of vision improvement. Again, your ophthalmologist can discuss this in more detail with you.

Treating abnormal new blood vessel growth (neovascularisation)

About 20% of patients with retinal vein occlusions develop abnormal blood vessels on either the iris at the front of the eye or on the retinal surface. These abnormal blood vessels can bleed or cause a marked pressure rise in the eye, leading to further loss of vision and pain in some cases.

This can normally be prevented by a specific type of laser treatment to the retina (called Pan Retinal Photocoagulation or PRP laser). It is important to note that this treatment is aimed at stabilizing and preserving the condition of the eye and so will not improve vision. The treatment is most effective if done before vision is lost due to new blood vessel growth. For this reason, patients with central retinal vein occlusions are normally reviewed every four to six weeks for six months.