 Home / Downloads & Publications / What is macular degeneration? / FAQ
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| 1. | Can younger people get macular degeneration? |
| 2. | Can visual hallucination be caused by macular degeneration? |
| 3. | What is the difference between wet and dry macular degeneration? |
| 4. | What is age-related macular degeneration? |
| 5. | Can nutrition help protect against macular degeneration? |
| 6. | Does macular degeneration usually affect both eyes? |
| 7. | How do I find out if I am suitable for photo dynamic therapy (PDT) and whether it will be offered on the NHS? |
| 8. | How is macular degeneration diagnosed? |
| 9. | Where can I find out about low vision aids? |
| 10. | How many people have age-related macular degeneration? |
| 11. | Can macular degeneration be treated? |
| 12. | Are lighting levels important |
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| 1. Can younger people get macular degeneration? |
| Early onset macular degeneration (birth to age 7) is a genetic disease. It is called Best disease or vitelliform macular degeneration.
Middle onset macular degeneration (age 5 to 20) is also a genetic disorder. This is commonly called Stargardt's disease, fundus flavimaculatus, or macular dystrophy.
People in their thirties or forties can develop a form of the disease that is also inherited. It may be called Sorsby's dystrophy, Behr's dystrophy, Doyne's dystrophy, or honeycomb dystrophy.
Finally, myopic macular degeneration can occur in people who are severely near-sighted due to extreme elongation of the eyeball. This condition can result in tears in the macula and bleeding beneath the retina.
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| 2. Can visual hallucination be caused by macular degeneration? |
| Charles Bonnet Syndrome results in hallucinations and occurs in patients who have eye diseases that prevent the normal nerve impulses from reaching the brain. As the brain tries to interpret the signals it may generate spontaneous nerve activity which causes hallucinations. Charles Bonnet syndrome is estimated to occur in 12% of macular degeneration patients and appears more often in women than men. It is also more likely to occur if both eyes are affected by MD. The hallucinations are complex and fully formed images. They are most frequently of animals, people, faces, or scenery. Some people also see writing. The hallucinations may last for seconds or for most of the day. They tend to disappear when people close their eyes. The syndrome may be experienced for a period ranging from days to years, although it usually disappears after a few months. People with Charles Bonnet Syndrome may need reassurance that that they are not "going insane" or suffering from a psychotic disorder. |
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| 3. What is the difference between wet and dry macular degeneration? |
| There are two forms of age-related macular degeneration: dry AMD and wet AMD.
In dry AMD the cells of the macula slowly begin to break down. Dry AMD is diagnosed in 85 percent of macular degeneration cases. Both eyes are usually affected by dry AMD, although one eye can lose vision while the other eye appears unaffected. Drusen, yellow deposits under the retina, are a common early sign of dry AMD. The risk of developing advanced dry AMD or wet AMD increases as the number or size of the drusen increases. Dry AMD can advance and cause loss of vision without turning into the wet form of the disease; however, it is also possible for early-stage dry AMD to suddenly change into the wet form.
Wet AMD, although it only accounts for 15 percent of the cases, results in 90 percent of the blindness; there is no early or intermediate stage of wet AMD. Wet AMD is caused by abnormal fragile blood vessels growing behind the macula which leak fluid and blood causing rapid damage to the macula. |
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| 4. What is age-related macular degeneration? |
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Macular degeneration is the collective term for over 1,500 conditions which affect central vision by damage to the macula, a small area of the retina at the back of the eye. Sharp, clear central vision is processed by the macular (also sometimes called the fovea) which is the central part of the retina and is about the size of a grain of rice.
AMD occurs when the layer of the retina responsible for nourishing the macula's light sensitive rod and cone cells, and for carrying away waste products, starts to function less effectively as it ages.
Cells in the macula break down, causing loss of sight in the central part of the field of vision but leaving the side vision, known as peripheral vision, unaffected. Although people do not lose all their sight, reading, recognition of faces, driving, watching television and colour definition become impossible.
AMD occurs in two forms. The most common is Dry AMD in which the cells of the macula decay and disintegrate. There is currently no cure or reliable treatment for this condition. The second form, Wet AMD, is more aggressive in its development. It is caused by the growth of abnormal blood vessels in the retina which can leak and lead to scarring and loss of central vision.
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| 5. Can nutrition help protect against macular degeneration? |
| A growing body of research suggests that nutrition may play an important role in AMD. Epidemiological studies which looked at dietary habits found that people who ate a diet rich in carotenoids (powerful antioxidants) had a lower risk of AMD.
In 2001 the AREDS study showed that antioxidant vitamins and zinc can reduce the risk of vision loss from Age-Related Macular Degeneration.
However high doses of antioxidants can have side effects so you should always consult your GP before taking supplements.
Vegetables rich in carotenoids are raw carrot, Kale, brussels sprouts, raw spinach, corn, broccoli, green peas, green beans, tomatoes, leaf lettuce, collard greens.
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| 6. Does macular degeneration usually affect both eyes? |
| MD often starts in one eye; it is then possible for the other eye to be affected too, sometimes several years after the first eye. It is therefore very important to monitor your vision and to report any deterioration to your GP immediately. |
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| 7. How do I find out if I am suitable for photo dynamic therapy (PDT) and whether it will be offered on the NHS? |
| Photo dynamic therapy is only suitable for patients with wet macular degeneration which has very recently been diagnosed. There are three forms of wet MD for which PDT may be a suitable treatment.
Treatment for two of these (classic no occult and predominantly classic) can be offered on the NHS, but the third (occult) is not authorised and can only be offered privately.
To assess whether you are eligible or not you need to know first whether your MD is wet or dry. If you have not been told and you have been diagnosed recently you should ask the consultant's secretary which one you have and whether PDT is a possibility. Dry MD cannot be treated by PDT. |
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| 8. How is macular degeneration diagnosed? |
| An eye care professional will perform a dilated eye exam and a visual acuity test, and view the back of the eye using a procedure called fundoscopy. If wet AMD is suspected a fluorescein angiogram may also be performed at the hospital eye clinic. This invloves putting a dye into the bloodstream by an injection into the arm. This dye is taken to the eye so that the eye care professional can see if the blood vessels are leaking. |
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| 9. Where can I find out about low vision aids? |
| If you have been registered blind or partially sighted you should have been referred to a low vision centre for assessment. The system works differently all over the UK. Whether you have been referred or not the best way to find out how to get access to aids and equipment is to call your local association for the blind. They know exactly where advice and equipment is available in each area and in many cases they have displays of equipment for sale. |
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| 10. How many people have age-related macular degeneration? |
| It is estimated that over half a million people are affected by age-related macular degeneration in the UK. It is the largest cause of people being registered blind in the UK. The number of people with AMD is forecast to increase significantly as people live longer. |
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| 11. Can macular degeneration be treated? |
| There is no current treatment to prevent vision loss for advanced dry age-related macular degeneration. However, a specific high-dose formula of antioxidants and zinc may delay or prevent intermediate AMD from progressing to the advanced stage.
The wet form of the disease can be treated with photodynamic therapy PDT and injections into the eye.
Photodynamic therapy invloves the injection of a light-sensitive drug into the patient's bloodstream. The drug circulates throughout the blood vessels, including the abnormal vessels growing beneath the retina. A low-intensity laser is used to cause occlusion (closing) of the blood vessels. This can prevent further leaking of blood and fluid and prevent the growth of more abnormal blood vessels. After PDT some occluded blood vessels may become incorporated into scar tissue. There can also be re-growth of abnormal blood vessels and these will require additional treatment. A course of PDT treatments over several months is often necessary. PDT is only approved for patients with "classic" wet macular degeneration, and is not generally used for "occult" MD.
Injections work by blocking vascular endothelial growth factor (VEGF), a protein that promotes blood vessel growth. They have the potential for helping all patients with wet MD. A drug is injected into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina). Because the production of VEGF is ongoing, routine injections into the eye are needed.
Vision already lost will not be restored by these techniques, but there are many low-vision aids which can help to alleviate the effects of loss of central vision. |
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| 12. Are lighting levels important |
| Good lighting helps to maximise the use of sight. Natural daylight is excellent as are daylight bulbs and high wattage bulbs (used with the appropriate shade to take that wattage). Anglepoint lamps pointing directly onto your work help and these can be in clip-on form to move around the house with you to use, for example, in the kitchen. Reducing glare and dazzle is important. Portable clip-on magnifiers are also useful to leave your hands free - for example, by the telephone,for sewing, chopping and other tasks. |
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