Dry age-related macular degeneration
There is currently no cure for dry age-related macular degeneration (AMD). With dry AMD, the deterioration of vision is very slow. You will not go completely blind as a result of dry AMD, and your peripheral (outer) vision should not be affected.
Help is available to make tasks such as reading and writing easier. Getting practical help may improve your quality of life and make it easier for you to carry out your daily activities.
You may be referred to a low vision clinic. These clinics can provide useful advice and practical support to help minimise the affect that dry AMD has on your life. For example, things that may make it easier for you to carry out close, detailed work include:
- magnifying lenses
- large print books
- intensive (very bright) reading lights
In the future, there may be more treatment options for dry AMD. For example, one option currently being looked into is rheopheresis
Rheopheresis
Rheopheresis is a blood filtration process where some of your blood is drawn out through a needle in a vein in your arm and transferred to a special machine. The machine filters the blood and then returns it to your body. To filter all of your blood takes between two to three hours.
Some trials have shown that rheopheresis can improve the vision of people with dry AMD. However, further research is needed before the technique is proven to be both beneficial and safe.
Wet age-related macular degeneration
There are a number of treatments that can help to stop the progression of wet AMD. In order for treatment to be effective, it is very important that wet AMD is treated as soon as possible. Once your sight has been lost, it cannot usually be restored. Some of the treatments that are available for this type of AMD are outlined below.
Photodynamic therapy
Photodynamic therapy (PDT) is a treatment that was developed in the 1990s. It involves having a light-sensitive medicine called verteporfin injected into a vein in your arm. The injection lasts around 10 minutes.
The verteporfin is able to identify the abnormal blood vessels in your macula (the part of your eye responsible for central vision). It attaches itself to the proteins in these blood vessels in your eye.
After 15 minutes from the start of the injection, a low-powered laser is shone into your damaged eye. It is shone over a circular area just larger than the lesion (wound) in your eye. This usually takes around one minute.
The laser is not powerful enough to cause any damage to your eyes, but the light from the laser is absorbed by the verteporfin and activates it. The activated verteporfin destroys the abnormal vessels in your macula without harming any of the other delicate tissue in your eye.
Destroying the blood vessels stops them from leaking blood or fluid, preventing the damage the vessels are causing to the macula. PDT therefore stops the macular degeneration from getting worse.
You may need to have this treatment every few months to ensure that any new blood vessels that start growing are kept under control.
Who can use PDT?
PDT is not suitable for everyone. It will depend on where the blood vessels in your eyes are growing, and how severely they have affected your macula.
PDT may be suitable if your visual acuity is 6/60, or better. This means that you can see from a distance of six metres what someone with normal vision can see from a distance of 60 metres. Around 20% of people with wet AMD can have PDT.
Side effects
The medicine that is used in PDT is called verteporfin. Verteporfin may cause some side effects including:
- visual disturbances, such as decreased, blurred, hazy, or fuzzy vision, blind spots, flashes of light, black spots, or grey or dark halos
- pain from having the medicine slowly injected (infused), usually in your back
- skin reactions, similar to sunburn, following exposure to sunlight, usually within 24 hours of treatment
Anti-VEGF medication
Anti-VEGF medication is a newer type of treatment that can also help to stop the progression of wet AMD.
VEGF stands for "vascular endothelial growth factor". It is one of the chemicals that is responsible for the new blood vessels that form in the eye as a result of wet AMD. Anti-VEGF medicines work by blocking this chemical and stopping it from producing the blood vessels.
The anti-VEGF medication has to be injected into your eye using a very fine needle. You will be given a local anaesthetic (a painkilling medication) so the procedure does not hurt.
Anti-VEGF medication is primarily used to stop wet AMD from getting worse. However, in some cases anti-VEGF medicines have also been shown to restore some of the sight that may have been lost as a result of macular degeneration. It is important to be aware that your sight will not be restored completely, and not everyone will experience an improvement.
Available medicines
The availability of anti-VEGF medication currently depends on your local Primary Care Trust (PCT) who will usually assess each case on an individual basis.
If you cannot get anti-VEGF treatment on the NHS, it is widely available on a private basis. However, you will have to pay for private treatment, which can be expensive.
On the NHS, the anti-VEGF medication you are likely to receive is called ranibizumab (the brand name is Lucentis).
Ranibizumab
Ranibizumab has recently been approved by the National Institute for Health and Clinical Excellence (NICE) for use on the NHS. Studies show that ranibizumab can help slow loss of visual acuity in over 90% of people, and may even increase visual acuity in around a third of people.
In order to qualify for ranibizumab on the NHS, you must meet several criteria related to your current visual acuity, and how severely the condition is affecting you. You can view the necessary criteria for NHS ranibizumab treatment by visiting the NICE website.
You will be given one injection of ranibizumab into your affected eye once a month, for three months. After this time, you will have a break which is known as a "maintenance phase". During the maintenance phase, your visual acuity will be monitored.
If your vision deteriorates by a loss of one line on the Snellen chart (a chart with blocks of letters that gradually get smaller) during this maintenance phase, you will be given another injection of ranibizumab. This monitoring will continue, and you will have injections as necessary, with at least one month in between injections.
The NHS will cover the cost of the first 14 injections in each eye that is being treated. If, after having 14 injections, you need to have further treatments, the manufacturer of ranibizumab has agreed to cover the cost.
If your condition does not show any signs of improvement after treatment with ranibizumab, or your condition continues to get worse, your treatment will be stopped.
Side effects
Ranibizumab can cause some side effects. Around 10% of people may experience some of the following side effects:
- bleeding from your eye
- pain in your eye
- inflammation or irritation
- inflammation of your eyelids (blepharitis)
- feeling like there is something in your eye
- increased pressure in your eye
- dry eye
- vitreous floaters: small pieces of debris that float in the vitreous humour (a clear, jelly-like substance) in the middle of your eyeball
- headache
- joint pain
- a common cold
The following side effects are less common, occurring in 1% of people or less:
- cataracts (cloudy patches over the lens in your eye)
- damage to your retina (the nerve tissue that lines the back of your eye)
- nausea (feeling sick)
- a cough
- allergic skin reactions such as a rash, redness, or itchiness
- anxiety
- anaemia (having a reduced number of red blood cells).
Before it is prescribed, your ophthalmologist will discuss the risks that are associated with ranibizumab with you.
Vitamins and minerals
Some research has found that high doses of the vitamins A, C, E, and beta-carotene, and the mineral zinc, may be beneficial in slowing down the progression of AMD.
Although vitamin and mineral supplements are available in pharmacies and other retailers, you should only take those that your GP or ophthalmologist recommends. High doses of these vitamins and minerals can result in side effects and, if they are not taken at the correct dosage, they may do more harm than good.
For example, vitamin E may increase the risk of heart failure in people who already have certain heart conditions or diabetes (a long-term condition caused by too much glucose in the blood). Also, beta-carotene may increase the risk of lung cancer in people who smoke.
Further scientific research into the effects of vitamins and minerals on AMD is needed before their effectiveness can be definitively proven. Currently, there is not enough evidence to suggest that certain vitamins or minerals may prevent or delay the onset of AMD.
Possible treatments
The treatments described below have been used in the past to treat AMD, or they are currently being investigated. They may not be as effective, or as safe, as those described above, and may only be available with special arrangements for clinical guidance, for example as part of a clinical trial (research to test one treatment against another).
Implanting lens systems
For people with advanced AMD (dry or wet), it may be possible to implant an artificial lens system into your eye. The lens is the clear part at the front of your eye that focuses the light coming in. Under local anaesthetic, your lens is removed and replaced with a series of artificial lenses.
One initial trial has suggested that this may improve the vision in up to 67% of people. The long-term effects are not yet known.
Macular translocation
Wet AMD can be treated using a surgical procedure that is known as macular translocation. The procedure involves cutting out the macular and moving it to a new location. This is done by cutting around the edge of the retina and rotating it. The macular is then repositioned on an area that is not affected by the lesion (wound) and scars that are caused by wet AMD.
Macular translocation is a very complex surgical procedure, and while it can improve the vision of some people, severe complications are possible. Therefore, you are unlikely to be offered this treatment, although future trials may reconsider its use.
Laser photocoagulation
In the past, lasers have been used to treat wet AMD. Lasers are shone into the eye to coagulate (make solid) the abnormal vessels that have formed there. This stops the vessels leaking.
The procedure itself can permanently damage the vision and the condition tends to reoccur after treatment. Laser treatment has now been replaced with photodynamic therapy and anti-VEGF medication.
