Eye Info

Treatments for Age-Related Macular Degeneration (AMD)

Summary: AMD is the most common cause of poor sight amoung people over 60.

• What is the macula?
• What is age-related macular degeneration (AMD)?
• What treatment is available for AMD?
• Laser treatment
• Photodynamic therapy
• Anti VEGF treatment
• Where can I get more advice?
• Further information

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What is the macula?

At the back of the eye is a layer of light sensitive tissue called the retina. The macula is found at the centre of the retina where the incoming rays of light are focused. The macula is very important and responsible for: what we see straight in front of us, the vision needed for detailed activities such as reading and writing and our ability to see colour.

What is age-related macular degeneration (AMD)?

Sometimes the delicate cells of the macula become damaged and stop working. We do not know why this is, although it tends to happen as people get older and is referred to as age-related macular degeneration. AMD is the most common cause of poor sight among people over 60 but never leads to complete sight loss as peripheral or side vision will remain undamaged. There are two different types of AMD:

Dry AMD: Around 90 per cent of people diagnosed with AMD have the dry type. It occurs when the cells of the macular become old and start to waste away meaning that these cells can no longer function properly. Dry AMD is also called non-exudative AMD.

Wet AMD: this is less common (10 per cent of cases) and occurs when tiny new blood vessels grow between the retina and the back of the eye. These blood vessels leak and bleed as they grow causing scarring of the macula. Wet AMD is also known as exudative or disciform degeneration.

What treatment is available for AMD?

Dry AMD

Although there is currently no treatment available for dry AMD, you can be helped to see better with a variety of optical aids which make use of the parts of the retina that are not affected. These range from brighter reading lights and magnifying glasses to more sophisticated equipment. Ask your doctor to refer you to a low vision clinic.

Wet AMD

People with wet AMD can also be helped to see better with optical aids and equipment. There is also some treatment available for wet AMD, however it is not suitable for use in all cases.

Laser treatment

Wet AMD can sometimes be treated by laser, a device that gives an intense beam of light. This is usually done as an outpatient and although it may cause some discomfort, it is not painful. A special contact lens is put onto the eye to help focus the laser onto the macula and the heat from the laser beam then destroys the leaky blood vessels. The benefit of this treatment is that it can prevent further degeneration of the macula. However, the laser treatment can damage healthy macula cells meaning that you might lose a little sight to save a lot. Laser treatment is only useful in about 10 per cent of people with wet AMD and this always where people have reported their symptoms early.

Photodynamic therapy

A new treatment for wet AMD has recently been announced called photodynamic therapy (PDT). With PDT a light-sensitive dye is injected into the bloodstream and is transported to the retina at the back of the eye. This chemical highlights the blood vessels that are growing abnormally. A low energy or 'cold' laser beam is then shone onto the macula. This makes the chemical react and destroy the leaking blood vessels without damaging the healthy tissue around the affected area in the back of the eye. More than one treatment is usually required.

PDT has been the subject of clinical trials and has been approved for use within the European Community. It is routinely available in the USA, Canada and most European countries. In the UK the treatment is offered at a number of centres and is currently the subject of an appraisal by the National Institute for Clinical Excellence.

It is estimated that between 5,000 and 7,000 people in the UK each year could benefit from PDT. However, it is important to note that wet AMD can progress rapidly. For PDT to be as effective as possible, individuals with early wet AMD need to be fast-tracked through the referral and waiting list processes in order to receive treatment before further loss of vision occurs.

PDT is unsuitable for long-established wet AMD and cannot restore sight that has already been damaged by macular degeneration. PDT cannot be used to treat dry AMD.

Anti VEGF treatment

Anti-VEGF drugs work by targeting VEGF (Vascular endothelial growth factor), a protein that helps the formation of new blood vessels. In the case of AMD these new blood vessels are unstable and tend to leak fluid and blood under the retina. The resulting scarring then causes irreversible sight loss. The anti-VEGF drugs inhibit the growth of new blood vessels, thereby minimising the risk of scarring.

There are currently three drugs that have been used in the treatment of wet macular degeneration: Macugen, Lucentis and Avastin.

Macugen

Macugen was approved by the European Medicines Evaluation Agency (EMEA) in Feb 2006 following extensive trials to show that it is safe and effective.

Macugen stabilises sight in approximately 70 per cent of cases and has been shown to improve sight in 20 per cent of patients who have been diagnosed early on in the disease process. It can be used for all lesion types in wet AMD.

Treatment consists of an injection into the eye every six weeks, usually for a minimum of two years.

Lucentis

Lucentis gained EMEA approval in Jan 2007. Again, this is based on extensive trials to show it is safe and effective. It can be used for all lesion types in wet AMD.

The trials have shown it to stabilise sight in more than 90 percent of cases and improve sight in up to 40 per cent of cases.

The license lays down a treatment plan which starts with three injections at four weekly intervals followed by further injections based on the consultants assessment of the patient. Patients need to be monitored every four weeks. In practice, patients receive on average eight injections in the first year and six injections in the second year.

Avastin

Avastin has not been approved by the EMEA for the use of treatment in the eye as it has not gone through proper clinical trails to determine safety and how effective it is.

Avastin has been approved as a treatment for colon and rectal cancer and is therefore readily available. When used for colon and rectal cancers, the drug is given into the vein of an arm. When Avastin is used for the treatment of wet AMD, it is given into the eye.

Ophthalmologists worldwide have been using Avastin off-label for AMT=D ('off-label' refers to prescribing medications for purposes for which they are not licensed).

Avastin has been showing success in stopping new blood vessel growth, and small studies and clinical observation suggest that the side effects may be similar to those observed in Lucentis and Macugen. However, since no large-scale long-term randomised controlled trials of Avastin have taken place, it is not possible to say with certainty whether Avastin has similar safety and effectiveness profile as the other anti-VEGF treatments. Clinical trails have therefore been set up in the UK to compare Avastin with Lucentis. It is uncertain at this time how often Avastin injections are given.

Where can I get more advice?

If you need advice on treatment options for your type of AMD, it is best to speak to your ophthalmologist at the hospital.

Further information

For further information, advice and support please contact:

RNIB Helpline:
Telephone 0845 766 99 99 (calls charged at local rates)
Email helpline@rnib.org.uk

The Macular disease also provides information and support for people dealing with macular degeneration and related retinal diseases they can be contacted at.

The Macular Disease Society
PO Box 1870
Andover
Hampshire
SP10 9AD
Helpline

Telephone 0845 241 2041
email info@maculardisease.org

RNIB is part of an organisation called AMD Alliance International whose role is to promote awareness of age-related macular degeneration – the leading cause of blindness in the western world. If you'd like more information please go to the AMD Alliance website at http://www.amdalliance.org/

1995-2007 RNIB, Registered charity number 226227

Content author: helpline@rnib.org.uk

Last updated: 13/02/2009 10:30