Age-related macular degeneration (AMD) is the leading cause of vision loss
in older adults, affecting more than 10 percent of those over the age
of 75. Its victims live with a large blurry or blind spot at the center
of their field of vision, making basic everyday activities—reading,
driving, navigating stairs—agonizingly difficult.
“As of right now, there is no cure for AMD. However, early detection
and timely treatment of AMD can help slow the progression of vision loss,
which is why regular exams are very important,” BCH retina specialist
Dr. Justin Kanoff told a crowd of more than 200 people during a free health lecture held
AMD is caused by the aging and deterioration of a small area of the retina,
known as the macula. The macula controls your central vision and your
ability to read, recognize colors or see the fine details of straight-ahead objects.
There are two types of AMD: dry (atrophic) and
“Dry AMD is the most common form of AMD, accounting for about 85
to 90 percent of cases,” Dr. Kanoff stated.
He said that over a period of years, AMD can progress through three stages:
• Early – You are unlikely to notice any symptoms at this stage,
which is characterized by the presence of medium-sized drusen (yellow
deposits beneath the retina).
• Intermediate - At this stage, you may notice some minor vision
changes, along with larger drusen and/or pigment changes in the retina.
• Late - There is severe vision loss at this stage.
“Since in its early stages AMD does not have any symptoms, a comprehensive
dilated eye exam of the back of the eye is the only way to diagnosis it,”
Dr. Kanoff said.
As the disease progresses, you may experience:
• Wavy or blurred vision
• Visual distortion such as straight lines for sentences on a page
• Extra sensitivity to glare
• Loss of color vision or intensity
• Difficulty seeing details in low-light levels
• Problems recognizing faces
Treatments to slow vision loss
Dr. Kanoff said, “Even though there are no cures for dry AMD, a
special combination of nutritional supplements can potentially slow down
the disease’s progression.”
Two large clinical trials conducted by the National Eye Institute (NEI)—the
Age-Related Eye Disease Study (AREDS; 2001) and a follow-up study called
AREDS2 (2013)—found that a special formula of nutritional supplements
could reduce an AMD patients' risk of progressing to the advanced
stage by about 25 percent over a five-year period. However, so far there
is no evidence that supplements benefit patients in the early stage.
The original AREDS formula included beta carotene, which was later found
to be linked to higher lung cancer rates in smokers. In the follow-up
AREDS2 study, researchers examined the formula without beta carotene,
replacing it with antioxidants lutein and zeaxanthin and lowering the
The AREDS2 special formula includes:
• Lutein (10mg)
• Zeaxanthin (2mg)
• Vitamin C (500mg)
• Vitamin E (400IU)
• Zinc (80mg)
• Copper (2mg)
“Although both AREDS and AREDS2 formulas are available over the counter,
it’s best to consult your doctor before you start taking either
of them. Determining the best formula for you depends on your medical
history, type of AMD and stage of the disease,” Dr. Kanoff warned.
If you’ve been diagnosed with AMD, Dr. Kanoff said that you may
be given an Amsler Grid, a grid of horizontal and vertical lines that
can monitor a person’s central visual field. Used at home as an
early warning system for changes in your vision, you’d view the
grid and check to see whether lines on it look wavy or distorted, or whether
areas of the grid are missing.
With the wet type of AMD, blood vessels break through the macula, causing
bleeding and swelling that leads to the loss of central vision. Wet AMD
progresses very rapidly and vision loss is severe.
“Ten percent of dry AMD cases will convert to the wet form. And,
individuals with high blood pressure are at higher risk,” Dr. Kanoff stated.
He then explained how ForeseeHome is an at-home monitoring device that
can help catch any progression from dry to wet AMD. You take a daily test
to check for tiny changes in your vision. The system then sends monthly
reports to your doctor’s office.
“Currently, the most effective clinical treatment for wet AMD is
anti-VEGF therapy,” said Dr. Kanoff. “This involves a periodic
eye injection of a chemical called an anti-VEGF, which hinders the growth
of new blood vessels behind the retina and keeps it free of blood leakage.
Studies show high rates of success for maintaining a patient’s current
level of vision and that it may even improve vision.”
He said in select cases, Photodynamic Therapy (PDT) can be added as a second-line
treatment or supplement to injections.
“PDT involves injecting a light-sensitive drug into your arm. Then
a cold laser directed into the eye activates the medicine and seals off
the abnormal blood vessels,” Dr. Kanoff explained. However, this
treatment isn’t a cure and doesn’t restore vision that has
already been lost. But one large clinical trial showed that PDT delayed
or prevented further loss of vision during a one-year follow-up with patients.
Ways to Lower Your Risk
Dr. Kanoff said that no one knows exactly what causes AMD. But currently
the best way to protect your eyes from AMD is to do the same things you
should do to avoid many other chronic diseases.
Research shows that AMD occurs less often in people who avoid smoking (which
happens to double your risk), get regular exercise and eat nutritious
foods. Food choices that can help reduce your risk include dark-green
leafy vegetables, eggs, carrots or any food high in beta-carotene, almonds,
and fruits high in vitamin C. Also, eating fatty fish one or more times
a week may reduce your risk for AMD.
If you wish to be screened or treated for AMD, schedule an appointment with
Justin Kanoff, MD by calling (303) 772-3300.
View PowerPoint slides from Dr. Kanoff’s lecture on “Advances in Treating Macular
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