What Is Macular Degeneration?
Age-related macular degeneration (AMD) is most often related to aging. There are some unusual types of macular degeneration that start very early in life, however, most patients with macular degeneration begin to notice problems with eyesight sometimes after age 50. Macular degeneration may be hereditary and therefore may run in families. Macular degeneration usually starts with the appearance of spots called drusen under the retina. Drusen are like age spots and do not usually change vision very much themselves. Most patients with drusen never have a serious loss of vision and only a few develop severe macular degeneration with loss of vision. In general, it is important to discover any change in eyesight as early as possible because the chance that treatment will help is greatest in the early stages of any eye problem. That is why you should test the eyesight in each eye, each day, especially if your doctor has told you that you have drusen.
A person with severe macular degeneration, who has lost the ability to see detail with each eye, rarely loses peripheral vision and will still be able to get along fairly well. It is very rare for someone with macular degeneration to lose both macular (detail) and peripheral (side) vision. Macular degeneration only very rarely causes total blindness. Almost all people with severe macular degeneration in each eye can see well enough to take care of themselves and continue those activities that do not require detail vision.
One very good way to test the central vision in order to detect even the smallest changes when they first appear is to use the Amsler grid (see below). If you note any changes you should see your eye doctor promptly.
Two Forms Of Macular Degeneration
There are two main forms of macular degeneration: a dry form and a wet form. In order to determine if you have macular degeneration and what form, the doctor will examine your eyes and often perform testing. By looking at the retina, the doctor will be able to tell if there is an abnormality. If drusen are found, you will want to schedule regular check-ups to make sure that no further damage is occurring. It may be necessary that photographs of each macula be taken to use for comparison with future examinations.
Dry Macular Degeneration
More than 90% of patients with macular degeneration have the dry form. This is characterized by drusen (yellow deposits under the retina) and a slowly progressive course. Many patients with dry AMD will retain good vision, while others will have significant loss of their central vision.
Although there is no medical or surgical treatment for this form of macular degeneration, eye sight may be helped somewhat with the use of special low vision aids, such as magnifiers, lights and telescopic lenses. With counseling, people can learn to use some of their peripheral vision to help them see more clearly and to cope more effectively with the practical tasks of every day life. Because the dry form of macular degeneration with drusen or atrophy can change into the wet form, it is important for anyone with the dry form to monitor vision (with the Amsler grid, for example) and report any new changes to their eye doctor.
Treatment For Dry Macular Degeneration
Although prevention of AMD is a goal that has not yet been achieved by medical research, recent studies such as the Age Related Eye Disease Study (AREDS and AREDS2) have shown that some patients with dry AMD will benefit from taking specific antioxidant vitamins. We have these vitamins available at our office, and they can also be purchased over the counter.
Wet Macular Degeneration
In the wet form of macular degeneration, abnormal blood vessels grow under the retina and lift the retina up, very much like the roots of a tree growing under a sidewalk. These abnormal blood vessels are called subretinal neovascularization. The abnormal blood vessels located under the retina may leak fluid, bleed, and lift up the retina. When this happens, vision is reduced. If this is treated promptly, vision loss can often be stopped or slowed. With newer treatments, vision can often be improved.
The earlier that abnormal blood vessels are discovered, the more likely that some or much of the central (detail) vision can be saved. The later abnormal vessels are discovered, the less likely treatment will be of benefit. In other words, pay close attention to your eyesight and see your eye doctor promptly if there is any type of change in your vision.
Treatment For Wet Macular Degeneration
Since the early 2000s, significant advances in the treatment of wet AMD have given us the chance to preserve vision and often improve it in patients with wet AMD. New medications, called antiVEGF agents, are injected into the eye every 4 to 12 weeks. These drugs (Avastin, Lucentis and Eylea) suppress the growth and leakage of abnormal blood vessels. This is a procedure that is done in the office under local anesthetic. Older treatments, such as laser and photodynamic therapy, are still done in certain situations.
Amsler Grid Self-Test
One reliable way for a person who has AMD to measure vision changes is to learn to use the Amsler grid self test. Use the Amsler grid recording chart to test your vision each day. If you notice any changes, please call your doctor’s office.
- Wear your reading glasses.
- Cover the opposite eye.
- Look at the center dot (the center of the crossing “X”) and keep your eye focused on the center at all times
- While looking directly at the center and only the center, draw any area of abnormality.
- Use different colored pencil for each day of the week. Change the test sheets each week.
- At the bottom of the sheet write the date of each test with the same colored pencil for that day. In this way, each
- Amsler sheet of paper will show a record of your vision each day for one week.
- Bring your Amsler tests to your next exam.
- If you see that the area of abnormality is getting bigger or changing–please call right away.
If your doctor finds an abnormality and suspects the wet form of macular degeneration (abnormal blood vessels), a special test called fluorescein angiography will be done. To do the test, dye is injected into a vein in the arm. The dye travels through the body including the eyes. With a special camera (not X-ray), a series of photographs of the retina is taken as the dye passes through it.