Age-related macular degeneration (AMD)
Age-related macular degeneration is a painless eye condition often referred to as AMD or macular degeneration. AMD causes the gradual loss of sight due to blurring or loss of central vision. This is often as a result of a deterioration of the macula, a yellow pigmented structure at the back of the eye that is responsible for our detailed colour vision. The severity of the disease depends on each person and on how quickly it is detected. It is important to remember that your peripheral vision (vision to the side) is usually not affected with AMD.
AMD is a chronic disease – it cannot be cured and in many patients sight cannot be restored after it is lost. However certain forms of the disease can be treated. Early detection is important to potentially stop the spread of the disease and to protect your sight.
AMD is the most common cause of sight loss in people over the age of 50 in Ireland and it’s estimated that seven percent of Irish people over 50 years of age are living with AMD. On account of our ageing population, the number of people in Ireland affected by this condition is expected to increase.
There are two forms of AMD, Early and Late. Only your eye care professional can tell you which form you may have.
In Early AMD the signs that the retina is being damaged are only visible to your eye care practitioner (optometrist or eye doctor). At this stage the damage does not affect sight and people are unaware of the condition. This highlights the importance of regular eye examinations to detect AMD in its early stages.
Some people progress from Early to Late AMD, where the condition causes loss of vision. There are two main types of Late AMD that can affect your sight – Dry AMD and Wet AMD.
Dry AMD is a more common form of the condition (around 85% of people with AMD have the dry form). It develops very slowly and can cause a gradual change in your vision. Dry AMD is caused when deposits, called ‘drusen’, form at the macula and lead to the deterioration of the retinal pigment epithelium and photoreceptors necessary for vision. Progression of Dry AMD varies from person to person but in most people it develops over many months or even years.
Some people with advance or late-stage Dry AMD may develop geographic atrophy (GA). GA occurs when photoreceptor cells within regions of the retina start to die or waste away (known as atrophy) and are not replaced. When your eye care professional is examining your eye, sometimes these regions of atrophy look like a map, hence the term geographic atrophy.
Wet AMD is a less common form of AMD but can develop more quickly and cause a rapid loss of vision. Because Dry AMD can sometimes progress into Wet AMD, you may also find Wet AMD referred to as Late of Advanced AMD. Wet AMD occurs when cells within the macula stop working and your body starts growing new blood vessels to fix the problem. Your eye doctor may refer to this as neo-vascularisation. As these new blood vessels grow in the wrong place, they cause swelling and bleeding underneath the macula, hence the name Wet AMD.
This leads to eventual scarring of the macula and can result in a sudden change in your central vision such as images appearing distorted, or objects looking smaller than normal. Although Wet AMD can develop quickly, it is treatable.
AMD can cause changes in your central vision, which can affect your ability to carry out day-to-day activities. Your peripheral vision is usually not affected and the severity of the condition varies from person to person.
Some symptoms you may notice include straight lines such as door frames or steps appearing wavy or distorted. You may also notice a smudge, shadow or gaps appearing in your field of vision. Sometimes people identify a glare in bright light or decreased levels of vision in low lighting or darkness. You may find challenges in reading small print, even with glasses, have trouble recognising colours or find that colours begin to fade. You have difficulty in recognising or distinguishing faces and may notice everyday activities such as driving or watching TV can become seriously affected over time.
If you notice any change in your vision, especially blurring, see your optometrist or doctor right away.
The exact cause of AMD is unknown. However, extensive research efforts over the last decade are playing an important role in uncovering some of the clues as to what may be causing the disease.
Researchers know that certain genes can cause AMD, but they don’t know what triggers the gene. While AMD can be inherited, many lifestyle choices can make progression of the disease worse.
Some risk factors that are believed to increase your chances of developing AMD include being over the age of 50 and having a family history of AMD. Having high blood pressure, a poor diet or being overweight are also thought to be risk factors for this condition. Also having fair skin and light eyes, being exposed to prolonged periods of sunlight can also potentially increase your susceptibility to developing this condition. Smoking or exposure to second-hand smoke can also increase your chances of developing AMD.
Unfortunately, because the exact causes of AMD are not yet known, you may develop AMD even in the absence of these risk factors.
To detect the earliest signs of AMD, it is recommended that you have an eye examination every one or two years by an optometrist or an eye doctor. This is particularly encouraged if you are over 50 years of age, or you have a family history of AMD or both.
You may have a number of eye tests during your eye examination. A photo may be taken of the back of your eye to look for any unusual features associated with AMD. You may be asked to look at an Amsler Grid (Below, you can find further information on how to use this simple test at home). You will be asked to read letters off an eye chart (Snellen chart). The optometrist or eye doctor may also shine a small light into the back of your eye to detect the presence of drusen, yellow retinal deposits which are often a feature of Dry AMD.
If it is suspected that you have AMD, you will be referred to an eye doctor for a thorough diagnosis and follow-up. Your eye doctor (ophthalmologist) will perform a detailed eye examination using a variety of tests to help diagnose AMD. These tests are also used to monitor the progression of AMD over time.
Your eye doctor may use eye drops to dilate your pupils, allowing them to see the back of your eye clearly. These eye drops may make your vision blurred for a short time after the test so it is important to consider taking someone with you. You may also need to wear sunglasses until the eye drops wear off as you may become more sensitive to sunlight.
You may also have non-invasive imaging tests, such as Optical Coherence Tomography (OCT) to examine your eyes more thoroughly. OCT takes a cross-section picture of your retina and allows your eye doctor to study each layer of the retina in more detail. This can help in reaching a diagnosis and also can provide guidance to treatment options, if applicable.
To assist with a diagnosis of Wet AMD, your eye doctor may perform a Fluorescein dye angiography. A harmless dye is injected into a vein in your arm that travels to the eye. This dye highlights the blood vessels in the retina so they can be photographed and studied in detail.
Checking Your Vision with an Amsler Grid
One easy at-home test for AMD is the Amsler Grid. You can download a copy of the Amsler grid here and use the grid following the instructions below:
- Hold the grid at reading distance, about 12 inches (30cm) away from your face.
- If you wear reading glasses, leave them on. Do not take the test while wearing varifocal or distance glasses.
- Cover one eye and focus on the centre dot.
- Make sure you can see all four corners of the grid.
- If the lines appear missing or wavy, you may have AMD. Contact your doctor immediately.
Remember, even if the grid looks normal, you should still attend regular eye exams for early detection of AMD.
Currently, there are no medical treatments for Dry AMD or GA, but research efforts are on-going to develop therapies to prevent or treat these conditions. Wet AMD on the other hand, can be treated if diagnosed early. Your eye care practitioner will suggest lifestyle changes that may help slow the progression of AMD, such as stopping smoking and eating a healthy diet. These changes are part of a healthy lifestyle and will benefit your general health too.
Age-Related Studies (AREDS1 and AREDS2) have shown that a combination of vitamins and antioxidants may help reduce the risk of progression of Early AMD to late-stage AMD. The recommendations include supplements containing vitamins C and E, zinc, copper, lutein and zeaxanthin. To find out more about what supplements may work best for you, speak with your eye doctor.
Treatment for Wet AMD is most often through a series of injections into your eye using a drug called anti-VEGF (anti-vascular endothelial growth factor). This treatment works by reducing the growth of new blood vessels. Response to this treatment is usually better in the early stages of Wet AMD, although even later stages can be stabilised. In some cases, individuals may notice improvements in their vision. However, if the damage has been left for a long time and scarring has already taken place, these treatments may not work well. Your eye doctor will determine if you are suitable for treatment and discuss the most suitable treatment plan for you.
Maximising the remaining vision that an individual has is a crucial step to take, and there are many low vision aids such as telescopic and magnifying lenses which may be of benefit. The wide range of assistive technologies for people with visual impairments provides plenty of choice for users at all stages of sight loss and this technology has also removed many barriers to education and employment.
General eye check-ups are important for people with AMD, as these individuals may still be at risk of developing other kinds of eye problems that affect the general population, some of which may be treatable.
No matter what level of vision a person may have, it is important to look after the eyes. To find out more about what can be done to take care of the eyes on a daily basis, please visit our Tips for Good Eye Health.
There are many layers and approaches to AMD research with efforts focused on enhanced understanding of disease, improved early diagnosis and the development of therapies that have the potential to prevent, delay or treat Dry and Wet AMD.
Internationally, researchers are trying to understand what causes AMD and why some people are affected and others are not. Since people with a close relative who has AMD may have an increased risk of getting the disease, researchers are closely looking at the role of genetics. Scientists are also investigating the involvement of oxidative stress and inflammation as a potential cause of the disease and what part our immune system plays in disease progression.
There are research efforts underway to look at ways of preventing the early stages of macular degeneration such as the development of drugs that may slow the build-up of toxic material. Neuroprotective compounds are also being examined to see if they can protect the cells of the retina.
There are also considerable research efforts being made to develop new and effective treatments for all forms of AMD, some of which are currently in human clinical trial. Clinical trials currently being investigated include gene therapies or cell replacement strategies that might one day help to restore sight. New ways to deliver medication into the eye (using less invasive methods) are also being examined. Eye implant technology is also another area of intense interest for AMD at present.
Information about clinical trials can be found on their website and can be searched by condition and trial location.
For further information, please contact the Research Department on 01 6789004.
Receiving a diagnosis can be overwhelming for anyone, but this is not a journey that you have to make alone. There are many groups and resources available to provide support for people living with AMD.
Fighting Blindness offers a free and confidential counselling service (Insight Counselling). For further information please contact firstname.lastname@example.org or call 01 6746496.
A mindfulness group is also available on every Wednesday at the Fighting Blindness office at 11am.
For technology support and guidance, the Dublin-based Technology Exchange Club meets every Monday at the Fighting Blindness office at 11am. Another Technology Exchange Club, based in Cork, meet every Saturday in the Cork City Library, Grand Parade, Cork City at 11am. The Cork-based club do not meet on Bank Holiday weekends or on the second Saturday of the month. For further information please contact email@example.com or call 01 6746496.
MIST (Macular Impairment Support and Togetherness) is a social and peer support group meeting on the last Wednesday of every month in Wynn’s Hotel in Dublin city centre. The group organises outings throughout the year including a number of walks. Everyone affected by macular degeneration is welcome. You can visit their website.
NCBI (National Council for the Blind in Ireland) provides support and services for people living with sight loss in Ireland.
Irish Guide Dogs for the blind helps individuals and their families to achieve improved mobility and independence.
There are also a number of useful websites which you may like to visit. For general information, you can visit AMD Ireland.
The Irish College of Ophthalmologists eye doctor website.
Retina International also has an international AMD toolkit on their website.
Last Updated: 18th February 2019