What is age-related macular degeneration?
Age-related macular degeneration is a disease that causes blurring of your central vision. The blurring happens because of damage to the macula, a small area at the back of the eye. The macula helps you see the fine detail in things that your eyes are focusing on.
Macular degeneration makes it harder to do things that require sharp central vision, like reading, driving, and recognizing faces. It does not affect side vision, so it does not lead to complete blindness.
There are two types of macular degeneration—wet and dry. The dry form is by far the most common type. The wet form is much less common, but it happens more quickly and is more severe.
You may have either type in just one eye, but over time you may get it in the other eye too.
What causes macular degeneration?
Macular degeneration is the result of damage to the nerve cells in the macula. The process that leads to this damage is different for each type.
- The dry form is a gradual process. As you age, the cells in the macula start to thin and break down, and waste deposits build up in the back of the eye. Over time, this damages the macula.
- The wet form happens when abnormal blood vessels grow in the back of the eye. These blood vessels break easily and leak blood and fluid under the macula. This can quickly damage the macula and distort your central vision.
Experts are still studying the causes of both forms.
What are the symptoms?
The main symptom of macular degeneration is dim or fuzzy central vision. Objects may look warped or smaller than they really are. You may have a blank or blind spot in the centre of your field of vision. As the disease gets worse, you may have trouble with tasks like reading and driving.
If you have the dry form, your vision will probably become blurry slowly. You may have it for several years before it affects your ability to read, drive, and do everyday activities.
Often the first symptom of the wet form is that straight lines look wavy or curved. In the wet form, vision loss happens quickly and can be severe.
How is macular degeneration diagnosed?
A doctor can usually detect macular degeneration by doing a regular eye examination and asking questions about your past health. You may have some vision tests, including an ophthalmoscopy. This test lets your doctor look at the inside of your eye and check for possible signs of this disease, such as drusen. These are yellowish white waste deposits that can build up at the back of the eye.
How is it treated?
At this time, there is no cure for macular degeneration. But experts are exploring many new treatments that hold hope for the future. Your doctor can keep you up to date on any changes in treatment that might help you.
Certain antioxidant vitamin and mineral supplements may help slow down vision loss in some people with moderate to severe macular degeneration. Talk to your doctor about whether this might help you.
Injections of medicine into your eye may slow down vision loss from the wet form of macular degeneration. Sometimes other treatments may be recommended.
How can you cope with vision problems?
There are many things you can do at home to make the most of your remaining vision. Try using aids like magnifying glasses, brighter lighting, and large-print books. Having a good support network is important too.
If you need more help, your doctor may refer you to an occupational therapist or rehabilitation specialist. These professionals can help you get the tools and training you need to cope with reduced vision. Local agencies may also offer services for people who have vision loss.
It can be scary to find out that you have a vision problem that may get worse. It is common to have a range of emotions. But if you feel very sad or hopeless, talk to your doctor.
Health Tools help you make wise health decisions or take action to improve your health.
Vision loss from age-related macular degeneration is caused by damage to the light-detecting nerve cells in the macula. The cause of this damage to the nerve cells is unknown. A person's genes and family history may play a role.
Age-related macular degeneration (AMD) can cause these symptoms:
- Central vision becomes dim, fuzzy, or less sharp.
- Reading requires more light than it did in the past.
- You find it harder to see people's faces clearly.
- Objects appear distorted or smaller than they really are.
- A new blank or blind spot develops in your central field of vision.
- Straight lines begin to appear wavy or curved. This is usually the first symptom of wet AMD.
- You have a loss of central vision that does not go away or becomes worse over time. The loss may be severe and rapid if you have wet AMD.
The symptoms of wet and dry AMD differ in two important ways:
How fast the vision changes are
- Dry AMD happens slowly. Vision changes may be so gradual that you don't notice them.
- Wet AMD happens suddenly. Symptoms tend to appear suddenly and get worse fast.
How bad the vision changes are
- Dry AMD symptoms are usually mild at first. Later, the symptoms can be more severe.
- Wet AMD tends to cause more severe vision changes and vision loss.
With dry age-related macular degeneration (dry AMD), the cells and blood vessels beneath the macula begin to thin and break down as they age.
When these cells and blood vessels stop working, the nerve cells in the macula that detect light can't work as well as they used to. As more and more of the nerve cells in the macula break down, vision loss very slowly gets worse.
You may have the disease for several years before it affects how you are able to read, drive, and do everyday activities. If you have AMD in only one eye, you may not notice minor vision changes, because your unaffected eye automatically makes up for vision problems in your other eye.
A small percentage of people who have dry AMD eventually develop wet AMD.
Wet AMD begins with the growth of abnormal blood vessels under the macula. These blood vessels break easily. They leak blood and fluid and cause scar tissue, all of which push against the macula. They change the macula's shape and cause it to send distorted images to your brain. Straight lines begin to appear wavy or curved, and objects may seem oddly shaped or smaller.
Scar tissue also cuts off the macula from the normal support cells that it needs in order to work. Nerve cells in the macula begin to die, causing a loss of central vision.
If not treated, the scar beneath the macula may continue to grow, affecting more and more of the nerve cells in the macula. Vision loss gets worse as more of the macula becomes involved. The entire macula may be destroyed by this process, resulting in a complete loss of central vision.
Treatment can sometimes delay or prevent further vision loss, but it cannot reverse vision loss that has already occurred.
With wet AMD, vision loss can happen fast—within months or even weeks. This can make it hard to adjust to the vision loss.
Even though AMD may affect central vision, it doesn't cause complete blindness. And most people keep good side vision.
What Increases Your Risk
The main things that put you at risk (risk factors) for age-related macular degeneration (AMD) include:
- Age greater than 55. Older age is the biggest risk factor for getting AMD.
- A family history of the disease. You are much more likely to get AMD if a close relative has it.
- Race. Whites appear to have a higher risk than blacks or Hispanics.
- Smoking. People who smoke are more likely to develop AMD than non-smokers.
Other risk factors for developing AMD may include:footnote 1
- Deposits at the back of the eye, called drusen. Eyes with large, soft drusen deposits are at a greater risk for developing abnormal blood vessels and wet AMD.
- A diet high in saturated fat and cholesterol.
- Not getting enough carotenoids, antioxidant vitamins, and zinc in your diet.
When should you call your doctor?
Call your doctor immediately if:
- You have a sudden, rapid loss of vision.
- You suddenly notice a new blank or dark spot in the centre of your vision that does not go away.
- Straight lines appear wavy or curved, or objects begin to change size or shape or appear distorted.
Your doctor will refer you to an eye doctor (ophthalmologist) if needed.
Call your doctor to discuss whether you need an eye examination if:
- You see either of the following on an Amsler grid:
- Lines that change or appear wavy and curved
- A blank spot that you have not noticed before in the grid
- You need more light to read than you used to.
- Colours seem faded or less vivid than they used to.
- Your vision seems to be getting more blurry.
Watchful waiting means to take a wait-and-see approach.
Watchful waiting is not appropriate if you have rapid vision loss or sudden changes in your vision. If you have any rapid vision changes, go to your doctor as soon as possible. Immediate treatment may be able to slow vision loss caused by wet AMD. Delaying treatment for wet AMD could mean further loss of central vision.
If you have dry age-related macular degeneration (dry AMD), watchful waiting is appropriate. You may never develop vision loss to the point that it disrupts your regular lifestyle.
Who to see
An ophthalmologist who specializes in problems with the retina and macula can diagnose which type of AMD you have. Also, several treatments such as medicine injections for wet AMD are done by an ophthalmologist.
Examinations and Tests
A doctor can usually detect age-related macular degeneration (AMD) with a regular eye examination. The doctor first will find out more about your symptoms, past eye problems, and other health conditions by asking you about your medical history.
Visual acuity test
The doctor will test your central vision with a visual acuity test. During this test, you cover one eye and read letters on a wall chart 6 m (20 ft) away. Central vision gets worse over time in a person who has AMD, and a visual acuity test can measure whether your vision has become worse since your last examination. The doctor may also test your visual field, which includes both your central vision and side (peripheral) vision.
Your doctor will look inside your eye using ophthalmoscopy. This test lets your doctor check for possible signs of this disease, such as drusen, which appear as yellowish white spots under the retina. Although some small drusen can usually be found in the macula as a normal result of aging, the presence of numerous large drusen is linked with AMD.footnote 1
Amsler grid test
An Amsler grid test can detect wet AMD. If you have wet AMD, lines on the grid appear wavy or curved instead of straight, or you may see a blank spot or hole on part of the grid.
For more information on vision testing, see the topic Vision Tests.
If your doctor thinks that you may have wet AMD, you may also have a test called an eye angiogram or an optical coherence tomography (OCT) to find out if abnormal blood vessels are growing beneath the macula. The tests can also locate leaky blood vessels under the macula and help your doctor find out if they can be treated.
If you have AMD and some loss of vision, your doctor may do a low-vision evaluation to help find ways for you to make the most of your remaining vision and keep your quality of life.
The Canadian Ophthalmology Society recommends that all people age 41 and older have a complete eye examination every 2 to 5 years to help detect AMD early. The following table summarizes the recommendations for comprehensive eye examinations:footnote 2
When to get a comprehensive eye examination
66 or older
Every 2 years
Every 3 years
Every 5 years
Every 10 years
There is no cure for age-related macular degeneration (AMD), but certain treatments may delay vision loss.
Your doctor can refer you to counsellors who specialize in helping people adjust to living with low vision.
Follow your doctor's advice for having regular examinations and for watching the condition at home (such as using an Amsler grid), because dry AMD can sometimes develop into wet AMD.
Certain vitamin and mineral supplements may help slow vision loss. Studies show that antioxidant vitamin and mineral supplements can help delay the onset of advanced AMD or can help prevent further vision loss in people who have moderate AMD.footnote 1 Check with your doctor before taking any natural health products. Some can have harmful side effects, especially if you take high doses.
Treatment for wet AMD can sometimes slow down or delay further damage to your central vision. But in most cases, growth of fragile new blood vessels in wet AMD starts again. And even repeated treatment is usually not effective over the long term in preventing some loss of central vision.
The main treatment for wet AMD is a medicine that is injected into your eye. This is called anti-VEGF medicine. Sometimes other treatments may be recommended, such as photodynamic therapy, which uses a light-sensitive medicine to block abnormal blood vessels beneath the macula.
Because wet AMD often causes rapid and severe loss of central vision, it is important not to delay treatment if your doctor recommends it.
You can't prevent age-related macular degeneration (AMD). But there are some steps you can take that may lower your risk of getting it.
- Have regular eye examinations. Eye examinations may help you find out if you are at risk for AMD or, if you have AMD, may detect it early. Early detection can sometimes delay loss of vision.
- Don't smoke. People who smoke are more likely to develop AMD than those who don't smoke. Even after you stop smoking, this increased risk may persist for many years.
- Get regular exercise, and stay at a healthy weight. These choices may lower your risk of getting AMD.footnote 1
People who have an increased risk for AMD should use the Amsler grid. Your doctor can give you one to use at home.
There's no treatment that can cure age-related macular degeneration (AMD). But there are things you can do at home to care for your eyes.
People with AMD should check the vision in both eyes using an Amsler grid every day or as often as the doctor recommends. If any of the lines on the grid change or begin to appear wavy and curved, or if you notice that your vision is getting worse, call your doctor.
Living with reduced vision
Reduced vision or vision loss from AMD can affect your life in many ways. How much it will affect you depends on your lifestyle and on how bad your vision loss is. Work with your doctor to find ways to make the best use of your remaining vision. There are things that you can do to adjust and to keep your quality of life as much as possible.
It is normal to feel unhappy about your loss of vision. But if your feelings of sadness are severe or do not improve, you may develop depression, which requires treatment. If you need help in dealing with your feelings about AMD, talk to your doctor and to your family and friends. Your doctor can also refer you to a counsellor who specializes in helping people adjust to living with limited vision.
Anti-VEGF medicines, such as aflibercept (Eyelea), bevacizumab (Avastin), and ranibizumab (Lucentis), can slow the vision loss that is linked to wet age-related macular degeneration (wet AMD). In some people, these medicines may improve vision. These medicines are injected into the eye.
The main treatment for wet age-related macular degeneration (AMD) is injections of medicine into the eye. But in some cases doctors recommend other treatments, such as:
- Laser surgery, which uses an intense beam of light to burn small areas of the retina and the abnormal blood vessels beneath the macula.
- Photodynamic therapy, which uses a light-sensitive medicine to block abnormal blood vessels beneath the macula.
Studies are being done on possible other treatments for AMD. You can talk with your doctor about the progress of new potential treatments.
- American Academy of Ophthalmology Retina/Vitreous Panel (2015). Age-related macular degeneration (Preferred Practice Pattern). San Francisco: American Academy of Ophthalmology. http://www.aao.org/preferred-practice-pattern/age-related-macular-degeneration-ppp-2015. Accessed April 30, 2015.
- Canadian Ophthalmological Society (2007). Canadian Ophthalmological Society evidence-based clinical practice guidelines for the periodic eye examination in adults in Canada. Canadian Journal of Ophthalmology, 42: 39–45. Also available online: http://www.eyesite.ca/resources/CPGs/COSVisionScreeningCPGEng_Feb07.pdf.
Other Works Consulted
- American Academy of Ophthalmology (2007). Vision Rehabilitation for Adults (Preferred Practice Pattern). San Francisco: American Academy of Ophthalmology. Available online: http://one.aao.org/CE/PracticeGuidelines/PPP.aspx.
- Despriet DG, et al. (2006). Complement factor H polymorphism, complement activators, and risk of age-related macular degeneration. JAMA, 296(3): 301–309.
- Fletcher EC, et al. (2011). Retina. In P Riordan-Eva, JP Whitcher, eds., Vaughan and Asbury's General Ophthalmology, 18th ed., pp. 190–221. New York: McGraw-Hill.
- Vedula SS, Krzystolik M (2008). Antiangiogenic therapy with anti-vascular endothelial growth factor modalities for neovascular age-related macular degeneration. Cochrane Database of Systematic Reviews (2).
Current as of: December 18, 2019
Author: Healthwise Staff
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine
E. Gregory Thompson MD - Internal Medicine
Christopher J. Rudnisky MD, MPH, FRCSC - Ophthalmology
Current as of: December 18, 2019