Age-Related Macular Degeneration
An estimated 15 million Americans have age-related macular degeneration (AMD), but unfortunately, most won’t know they have it until they begin to suffer vision loss. AMD is the leading cause of blindness and central vision loss among adults over age 65.
Learning about this disease and scheduling an examination with a retina specialist could help preserve vision for a lifetime.
How does AMD occur?
During normal aging, yellowish deposits, called drusen, form under the retina, which is the light-sensitive layer of tissue at the back of the eye that provides clear, sharp images.
As drusen increase in size and number, they can interfere with proper functioning of the retina, damaging or killing the light-sensitive cells of the macula.
Because the macula’s light-sensitive cells provide the ability to have sharp, detailed vision, the results can be blurring of central vision and a devastating impact on the ability to enjoy activities of daily life, such as reading, driving, or even recognizing the face of a friend or family member.
This form of age-related macular degeneration is called dry AMD. Dry AMD can be a precursor to wet AMD.
Retinal scan showing dry AMD. Notice the tiny yellow spots (drusen).
Wet AMD occurs when abnormal blood vessels behind the retina start to grow under the macula. These blood vessels often leak blood and fluid, damaging or killing light-sensitive cells—loss of vision occurs quickly.
Although approximately 80 percent of patients with age-related macular degeneration have dry AMD, wet AMD is responsible for 80 to 90 percent of severe loss of vision or legal blindness associated with this disease.
|Early stage wet AMD||End stage wet AMD with scarring|
Can I live a normal life with AMD?
AMD may be a difficult condition, but it is not as devastating as people fear when they are diagnosed and only rarely leads to complete blindness. Millions of Americans actually live healthy, independent lives, despite having age-related macular degeneration.
It is important to learn about the disease and work with a retina specialist, who will put a treatment plan in place. These physicians have the ability, training, and experience to treat all medical and surgical aspects of AMD and other diseases of the retina.
A retina specialist can also direct you to a support group and suggest access to rehabilitation options, including a variety of tools and resources that can make everyday living with AMD a little bit easier.
Video: Hope in Sight: Living With Macular Degeneration
The earliest signs of AMD in the retina can be detected by a retina specialist before you have any vision loss, but those who have had the disease for some time may notice changes in vision which are symptomatic of dry and wet AMD.
Dry AMD symptoms
- Need for brighter light when reading
- Difficulty adapting to low light levels
- Increased blurriness of printed words
- Decrease in brightness of colors
- Blurred spot in the center of the field of vision
- Blank or black spot in the field of vision (spot will start small and grow over time, possibly leading to blindness
Wet AMD symptoms
- Abrupt decline in central vision
- Visual distortions, such as straight lines appearing wavy, or objects appearing larger or smaller than they are
- Well-defined blind spot in the center of vision
It is important to pay close attention to any decline in central vision—both near and distant. If you notice any of these signs or symptoms, schedule an examination with a retina specialist.
Many people ask if age-related macular degeneration can be prevented. Like most things in life, there is no easy answer.
The primary risk factor for AMD is age—the older you are, the greater your risk. Also, people with a family history of AMD are at higher risk, as are women and people of European descent.
Some lifestyle factors are also known to increase your risk for AMD:
- Cigarette smoking
- Hypertension (high blood pressure)
- Excessive sun exposure
- Diet deficient in fruits and vegetables
The best way to detect AMD is an examination by a retina specialist. The following are some typical methods he/she will use to check for AMD.
Dilated eye exam
In this examination, a physician uses eye drops to dilate, or widen, the pupil to examine the retina. Regular dilated eye exams are important, especially for those who are at a higher risk for developing AMD.
If you are over age of 50, it is a good idea to schedule an eye examination every one to two years to look for the earliest signs of AMD before any vision loss has occurred.
Ocular coherence tomography
The physician may suggest an optical coherence tomography (OCT) exam. This test provides cross-sectional images of the retina that show its thickness, helping determine whether fluid has leaked into retinal tissue and other changes that happen with AMD.
Another way to detect AMD is by using an Amsler grid test. In this test, the patient covers one eye at a time and stares at the black dot at the center of the grid. If the straight lines appear broken, crooked, wavy, bent, or distorted, the patient may have AMD.
It is important to note that this test is hardly sufficient to rule out the possibility of AMD, as many people with the disease may see no abnormalities on an Amsler grid.
Visual acuity test
Because AMD affects visual acuity, an eye chart can also be an indicator of the development of AMD.
Treatment and drugs
There is no known cure for AMD, but early detection and proper treatment can protect vision from further deterioration.
Dry AMD treatments
Currently, no medical treatments exist for dry AMD, but the retina specialist will suggest strategies to slow its progression—taking vitamin or mineral supplements, for example.
If you have Dry AMD, it is extremely important to follow your retina specialist's eye examination schedule. Also, if you experience new symptoms or your notice any deterioration in vision, see your retina specialist right away.
Wet AMD treatments
There is a variety of medical treatments that can help stop further vision loss caused by wet AMD:
- Laser surgery – These procedures can eliminate abnormal blood vessels and prevent additional leakage, bleeding, or growth.
- Photodynamic therapy – In this treatment, the patient is injected in the arm with a medicine that is triggered by a laser to destroy abnormal blood vessels.
- Eye injections – These medicines destroy abnormal blood vessels in the eye and prevent them from leaking.