The back of your eye is covered with cells that detect light. These cells form part of the layer known as the retina. The macula is at the centre of the retina and is densely packed with cells that allow you to see fine details in colour. The macula is responsible for fine vision, such as reading and recognising people.
In macular degeneration there is damage to the cells in the macula. In the early stages this can cause small print to appear distorted. As one eye is usually affected before the other you may not notice these early changes. There is no pain with the condition. As it progresses the central distortion or fuzziness can turn into a blank spot which makes it hard to read small print or recognise faces. Macular degeneration does not usually lead to total sight loss: if you have the condition you are likely to retain your side vision which enables you to get around a bit easier than without.
Wet macular degeneration happens when new blood vessels grow behind the macula. Blood leakages and scarring prevent the cells from working well and central vision becomes poor. This type of macular degeneration is less common, accounting for around one case in 10, but untreated leads to more severe visual loss. There are now treatments that can stabilise the condition but they are not a cure.
Dry macular degeneration happens when debris builds up behind the macula. The cells of the macula become unhealthy so the signals which would allow you to see are no longer carried by nerves from the back of the eye to the brain. It is the more common form of the condition and tends to happen to older people. It is usually gradually progressive and may lead to moderate visual loss, however this is often not severe. Effective treatments are not yet available.
There are strategies to help you cope better despite the damage. People with macular degeneration will usually find properly prescribed magnifiers helpful, although in its early stages simple over-the-counter magnifiers will be a good start.
Macular degeneration is also known as age-related macular degeneration as it usually occurs in older people, you may find this abbreviated as AMD. Younger people can experience sight loss due to problems with the macula. These problems are generally known as macular dystrophies, and can run in families.
We don’t know exactly why macular degeneration takes place. It is more common in older people. There can be signs of macular degeneration in one in 10 people aged 66 to 74 and around one in three people aged 75 to 85. Women are more likely to have macular degeneration than men. Some sorts of macular degeneration seem to run in families. Smoking is linked to macular degeneration. In some, but not all, research papers it has been suggested that increased exposure to the sun and to visible blue light over a lifetime may increase the risk of macular degeneration. Macular degeneration is more likely to be found in Caucasians than in people of African descent. High blood pressure can increase the risk as can obesity, and a diet high in hydrogenated or saturated fats.
Protecting your eyes from the sun, eating a well-balanced diet with plenty of fresh fruits and vegetables and stopping smoking may all help to delay the progress of macular degeneration.
Recent research has looked at how certain supplements can cut the chance of developing macular degeneration or slow down its progress. One study showed that supplements including vitamin C and vitamin E, which are known as antioxidants, helped when taken in combination with zinc. Lutein and zeaxanthin, found in green leafy vegetables and eggs have also been shown to have protective effects. More trials are going on to test the effect of these in combination with fish oils. These are not indicated for everyone and there are health risks from taking very high levels of certain supplements, especially if you are a smoker or have been in the last 10 years, so it is important to consult your doctor before taking these supplements.
If you want to monitor your own central visual field it can help you detect early visual changes: Cover one eye, so you can spot changes in each eye in turn. Make sure you have good lighting on the page. Wear your usual reading glasses, if you need them. Cover your right eye (without pressing hard). Use your left eye to stare at the spot in the centre of the grid. Keep your eye still, and notice the horizontal and vertical lines to the left and right, above and below the central dot. Are any of them blurry, distorted, missing or wiggly? Then repeat the test with your other eye covered. If you notice any problems, repeat the test after a few hours. If the lines remain distorted or broken, make an appointment with your optometrist.
If your GP or optometrist detects signs of macular degeneration they may refer you to an ophthalmologist at a hospital. The referral may be urgent in the case of wet AMD or routine for untreatable dry AMD.
You will be sent an appointment to see the ophthalmologist. Take someone with you who can accompany you home as you will be given eye drops which widen your pupils and give the specialist a clearer view inside. These drops can leave your vision blurry for a few hours so someone else should drive home.
The ophthalmologist will use a bright light to look inside your eye. In some cases, that will enable them to diagnose macular degeneration. Alternatively, they may use a new sort of computerised scanner (called OCT) which can see the layers beneath the retina. They should explain about the progression of the disease and talk about the sort of help you can get.
If the specialist needs further information about changes at the back of the eye they may suggest that you have a test that uses a dye injected into a vein in your arm to show up the path of the blood vessels around your macula. This test is called fluorescein angiography, often termed FFA. Dye is injected into your arm and travels to the blood vessels at the back of the eye. The specialist takes photographs using blue light, you may feel dazzled or nauseous during and after the test, but it is not painful. It helps the ophthalmologist understand what sort of macular degeneration is present and whether treatment can help.
There are now well-established treatments for the wet form of macular degeneration whilst other newer treatments are being evaluated.
NICE is the government body that looks at treatments and decides which should be available on the NHS, it has looked at various treatments for macular degeneration. NICE recommends that for most patients with wet AMD treatment with Lucentis (Ranibizumab) is effective and should be available to patients fitting defined treatment criteria in the NHS. See here for current guidance. Aflibercept injection has also been approved and photodynamic therapy.
If you have access to the Internet you can download NICE assessments for moderately advanced dry AMD here. This will give you some knowledge to help you discuss possible treatments with your ophthalmologist.
NICE assesses new treatments as they become available.
There are lots of ongoing developments in the area of treatment for wet macular degeneration. Most treatments cannot bring back damaged cells, but can stop your vision getting worse. Treatments that may offer some visual improvement for some people are available.
The sight problems with wet macular degeneration are due to blood vessels growing where they affect the cells you use for detailed vision. Treatment needs to happen as soon as possible as your vision can get worse quickly with wet macular degeneration.
Drug treatments (known as anti-angiogenics or anti-vascular endothelial growth factor agents) work by reducing the growth of blood vessels, reducing bleeding and leaking. The drug is injected into the gel inside your eye and can stop blood vessels growing and even cause them to regress, which might improve your sight. The injection is painless and needs to be repeated every month for the first three months then on an ‘as required’ basis. Monthly follow-ups with your ophthalmic team are required in the long term to enable early intervention and re-intervention when needed. This treatment is usually only suitable for people with recent onset of wet macular degeneration. Unfortunately, people with long standing visual loss due to wet AMD usually have scar formation in the macula already and do not benefit from these treatments.
No one has yet found a successful treatment for dry macular degeneration, there are research projects looking at stem cell and gene therapy at present. You can get news of research projects on the Macular Society website.
Although there is no treatment for the condition, this does not mean that nothing can be done to help you. You can use your remaining vision with the assistance of magnifiers, equipment, training and support. Over three quarters of all people with low vision can be helped with simple magnifiers and advice on appropriate lighting, however, even a simple magnifier needs careful use and you may need to be shown how to use it. Be sure to ask about having a low vision assessment.
To find out about equipment that might help, you can contact RNIB, speak to your GP or local authority’s social care department about local support. The Macular Society has a leaflet about low vision aids and also offers a counselling service. There is likely to be a group for people with sight problems local to you that can help you with practical training and support, just contact the Macular Society.
Macular degeneration can be frustrating for the person experiencing it. Suddenly it can become harder to read small print, look up telephone numbers, tell the time on your watch and more. It is also confusing because your peripheral vision may be unaffected. Make things easier by ensuring that there is good light at home. Look into obtaining large print or talking books and write notes in a clear bold pen. Support the person you care for to find out more about local low vision services so they can access magnifiers and other equipment to help them be independent. If your loved one lacks confidence getting out and about, check out the Macular Society’s information on being a ‘sighted guide’ for someone with sight problems. You can also enquire about the availability of mobility training through the local rehabilitation officer. Local branches of the Macular Society often offer excellent support and are well worth getting in touch with.
It is not necessary to be registered as visually impaired or severely visually impaired, to be able to access low vision aid services. Low vision aid services in most areas have a relatively open access policy and your ophthalmologist, eye nurse or optician may be able to refer you without you needing to be on the visually impaired register.
If one eye is already affected and you are getting symptoms in the other eye, most NHS or private retinal specialists will have a rapid access system in place which you can access directly or through your GP.