Age-related
Macular Degeneration: What you should know and do about
this major health crisis
By
Dr. Bruce P. Rosenthal, Chief of the Low Vision Programs
Lighthouse International, Adjunct Professor Mt. Sinai
Hospital, NY, Chair of the Scientific Advisory Board,
AMD Alliance International and author of Living Well With
Macular Degeneration (email: brosenthal@lighthouse.org)
Age-related macular
degeneration (AMD) is a little understood, but destructive
eye condition that has begun to emerge as one of the major
health crisis of the 21st century. How could a relatively
unknown medical condition, which is the leading
cause of visual impairment among persons age 75 and older
in the United States (Prevent Blindness America) be given equal billing
along side with other serious health conditions such as
heart disease, diabetes, stroke, and cancer? How can
age-related macular degeneration, a condition affecting
6 million people with another 13-15 million people with
pre-symptomatic signs (AMD Alliance International 2003)
suddenly appear on the scene?
There are many reasons
that contribute to the huge numbers of people affected
by AMD including the increasing lifespan in the United
States. Longevity has increased among females, as well
as males, in the United States and the around the world.
In fact, women can expect to live at least 23 more years
at age 60 and men can expect to live 18 more years. And
many more people will be living into their 9th
and 10th decade and beyond as well. In addition,
modifiable risk factors such as smoking and possibly diet
are contributing to the increasing numbers of individuals
who will begin to lose their vision.
There
are 97 million Americans age 45+, and by 2010, this number
will balloon to near 120 million (US census bureau).
Figure 1: Estimates of the US population
at age 60+ to 85+
|
Age |
Population |
|
60+ |
48,883,408 |
|
65+ |
36,293,985 |
| 85+ |
4,859,631 |
Source:
U.S. Census Bureau, July 1, 2004 estimates.
But
there are ways in helping yourself, a loved one, family
member, or friend perhaps delay the onset of AMD by decreasing
your risk for the condition. Let’s look at some celebrities
who developed age-related macular degeneration, before
getting into greater detail on ways to perhaps delay the
onset of the disease as well as retain and improve your
quality of life.
The
following is a group of very entertaining, diverse, high
profile, and influential people of the twentieth century
who developed age-related macular degeneration in what
they probably considered to be their “productive” years.
They included Don Knotts, who we all knew as Barney Fife
on television, as well as the incredible and incomparable
Bob Hope, whose career was followed through the years
on radio, in the movies or on television. It included
as well Bob Hope’s co-star Jane Russell (still alive and
very active), the world renowned artist Georgia O’Keefe,
one of the greatest golfers of all time Sam Snead, as
well as the Editor-in-Chief of Time-Life magazines, Henry
Grunwald.
Long
after being diagnosed with AMD, this incredible group
of people continued to be active in their respective careers.
Don Knotts, for example, continued his television career
for over 25 years after being diagnosed in his ‘50’s,
Bob Hope went on entertaining millions as well as playing
golf into his 90’s, while Henry Grunwald wrote three books,
including his autobiography, despite the fact that he
had a profound loss of vision loss from AMD. Even Georgia
O’Keefe continued her painting, even though she noted:
“It’s like there are little holes in my vision. I can’t
see straight on very well but around the edges are little
holes where I can see quite clearly”. They coped and
continued on with their life. So can you as well as a
loved one or friend.
Even
though this group was very successful in life, macular
degeneration may often put one in some very embarrassing
situations. An example is given by Henry Grunwald in
his book “Twilight” (Alfred A. Knopf, Publisher) which
detailed the way he reacted as well as coped with AMD.
He describes an experience at a party where he assumed
that the tall striking blonde in front of him was his
friend Diane Sawyer. He stopped himself at the last moment
when he heard someone addressing her as “Ma’am” and realized
he was in front of Princess Diana. Henry’s (that’s the
way he introduced himself) way of fighting back was humor
as well as strategies learned at the Lighthouse International
in New York City, such as feeling the toothbrush before
applying the toothpaste or asking the restaurant to Fax
a menu ahead of time so he wouldn’t struggle with it while
ordering.
As
a reader of biographies, it is always interesting for
me to find out that moment or instance when one individual
can make the leap to greatness while others with similar
talents, as well as aspirations, stay locked in at a specific
level. I an intrigued as well, to find out how an individual
continues on with life with the same great energy, drive,
and enthusiasm despite the fact that they have a severe
loss of vision from age-related macular degeneration.
My strategy in finding out these secrets, as the Chief
of the Lighthouse International Low Vision Programs in
New York City (often thought of as the Mayo Clinic of
low vision in the United States) is to be straight forward
and ask them the following question:
“Why are you able to continue on enthusiastically
with your work, pursue your hobbies and interests and
even travel, despite profound changes to your vision while
your contemporaries basically stop living?”
The answers in many instances are the same:
“It could have been a lot worse.”
“I think about the alternative.”
“I have to adapt to the hand I was
dealt.”
The life strategy that catapulted them to stardom or an inner
drive that propelled them to succeed in business, the
field of entertainment, in sports, continues to motivate
them to go on despite the significant loss that stops
other people in their tracks. Nothing, in fact, seemed
to slow down Bob Hope who lived to 100.
Knowing
more about AMD will empower you, a loved one, family member,
or friend continue to enjoy every day after being diagnosed
with age-related macular degeneration. Here are some
questions as well as answers to the following important
questions on managing with AMD that we will cover.
What is the macula and age-related macular degeneration and
can it lead to blindness?
What are some of the symptoms that may indicate that I am
developing the condition?
What are some of the treatments available to slow or delay
the progression?
What are low vision devices?
How often should I have my eyes checked?
And what are some of the preventative methods that may slow
down the progression if you are at risk.
What is
the macula and why can’t they replace it like a cornea
or the cloudy lens of the eye (cataract) which is replaced
following cataract surgery?
The
retina, which lines the inside of the back of the eye,
is a very light sensitive tissue. It is very similar
to the film in a camera except that it is a very specialized
film. The retina is made up of two different systems.
The macula, or central 20 degrees of the retina, helps
you see straight ahead while the peripheral system allows
you to see on the sides. The peripheral vision, in fact,
allows you to move through a crowd without bumping into
other people as well as travel around at night. The retina
has a wonderful ability, when it is healthy, to rapidly
adjust, as well, to light when you come indoors, go into
a dark movie theatre, or go to the bright outdoors as
well as be able to see in black and white or vivid colors.
The
macula of each eye, which is the “keystone” to most of
our important visual functions, is made of very specialized
cells. It is the area that is packed with most of our
color vision as well as our sharpest and detailed vision.
You can almost view the macula as the area of our “eagle”
vision.
Cross
section of eye
Credit: National Eye Institute,
National Institutes of Health Ref#: NEA09 (www.nei.nih.gov)
Again
the macula may be considered the “workhorse of the eye”
and helps us in most of our important day-to-day visual
tasks such as: seeing the features of someone’s face,
the print on a medication bottle, the highway signs when
driving, the ability to thread a needle, seeing the color
of the traffic light, the numbers on the electric bill,
or help us to write a check as well, as balance our checkbook.
Serious visual disturbances will therefore develop when
the macula is affected.
As
noted, the macula is a very specialized area that not
only helps you to see the letters on an eye chart (visual
acuity) but helps us see how black the letters are (also
known as contrast). Too little “contrast” may result
in difficulty walking down a poorly light staircase, seeing
a curb, or in seeing the menu in the restaurant, especially,
when the lights are dimmed and there is a lonely candle
sitting on the table as well as the food on the plate.
Dry and
wet macular degeneration
There
are two types of macular degeneration that can affect
the sensitive light receivers in the eye known as the
cones and the rods that are packed into the macula. The
first is known as the dry
(atrophic) type of macular degeneration and
accounts for about 85 to 90% of all individuals having
the condition. The second type of AMD, known as the
“wet” type (also known as exudative) is present in about 10-15% of people with AMD. It is much more aggressive
and destructive but may respond to some of the newer available
treatments. Both types of macular degeneration may irreparably
destroy the sensitive photoreceptors, the rods and cones,
so they minimally or no longer function. Early
detection and intervention is therefore essential!
So
what is the answer on why you can replace the lens in
an eye with a cataract but cannot replace the retina?
Cataract surgery involves removal of the cloudy lens of
the eye and replacing it with a clear “intraocular implant”
while corneal surgery may involve the transplant of a
new cornea that was stored in the eye bank. The macula
however cannot be replaced at this point in time. It
is a very intricate structure with millions of fibers
carrying the visual signals through our optic nerve to
the centers of vision in the brain (the visual cortex).
Efforts to rotate the retina and create a “new” macula
has had very limited surgical success. Stem cell transplants
for the retina and macula are still at least 15-20 years
away, according to most retinal research experts, while
insertion of electronic chips into the retina is still
in the infancy of experimentation and relatively primitive.
Risk factors
for Age-related macular degeneration:
As
noted, age is considered to be one of the risk factors
in developing age-related macular degeneration. The older
you are, the more chance of developing the condition.
The numbers of people with the signs of age-related macular
degeneration vary greatly but there are over 13 million
people with signs of the condition over the age of 50.
According to statistics published (National Eye Institute
http//www.nei.nih.gov and Prevent Blindness America) the
risk increases as you get older. There is a 2% chance
of developing advanced AMD by age 70 and 14% by age 85.
Smoking,
the one agreed upon, modifiable risk factor, has been
shown in clinical studies to increase the risk of developing
AMD by 3 to 6 times! In fact Australia has cigarette
packs labeled, “smoking causes blindness!” And cessation
of smoking has been shown to decrease the risk of AMD
as well. In fact most researchers agree that the risk
disappears after not smoking for 20 years. There seems
to be more and more evidence accumulating, as well, that
AMD runs in families and there are some genes that seem
to indicate a higher risk for people having them (the
Complement H factor or CFH gene discovered in 2005 is
an example).
Sunlight,
obesity, elevated cholesterol levels, dietary habits,
physical activity and cardiovascular disease may also
be risk factors as well. In fact, one major study showed
that vegetable, monosaturated, and vegetable monounsaturated
and polyunsaturated fats increased the risk of AMD when
linoleic acid (includes oils such as sunflower oil and
linseed oil) was low. BMI or body mass index seemed to
be a risk factor as well since the AMD appears to increase
as the BMI increases. And the evidence of drusen (waste
deposits in the retina) would appear to be another indicator
of AMD.
Can you
go blind from AMD?
Eye
doctors often abbreviate the term “legal blindness” to
blind, a term that indicates an individual has no useable
vision. Understanding the difference can make a huge
emotional difference. The US definition of “legal blindness”
is vision which is 20/200 or less, with best-correction
in the better eye (or a visual field of 20 degrees in
the better eye in the widest meridian). It in no way
implies no vision! Legal blindness is used by the Federal
Government, as well as the commissions for the blind and
visually impaired in each state, to access services or
for income tax purposes. 99% of people with macular degeneration
have useable vision! And 99% of those thousands of people
with a diagnosis of AMD should be able to improve their
quality of life
with
specialized low vision devices.
How do
you know when you might be developing AMD?
Regular
eye examinations by your family optometrist or ophthalmologist,
is the first line of defense, for any one over the age
of 40. And 60 is another age when vision should be checked
regularly. Regular examinations are especially essential
for those at risk. But there are other indications that
your vision may be changing.
1.
You
have difficulty in reading with your “best” eyeglass correction.
2.
Letters,
telephone poles, or bathroom tiles appear wavy.
3.
The
print in the newspaper appears to be too light.
4.
Words
may have distorted or missing letters.
5.
There
are problems in seeing the color of the traffic light.
6.
Matching
clothes when dressing is a problem.
7.
There
is a lot of glare sensitivity both indoors and outdoors.
8.
Even
visual hallucinations are a sign that there may be a problem.
Treatments
available for AMD
Your
primary eye care doctor, optometrist or ophthalmologist,
may refer you to a retinal specialist. Retinal specialists
are ophthalmologists specializing in the treatment of
age-related macular degeneration. They will recommend
a battery of specialized tests, to see if any treatment
is indicated including fluorescein angiography, indocyanine
green angiography (retinal photos) or OCT (optical coherence
tomography) to look at a cross-section of the macula.
The
specialist may also recommend one of the approved FDA
treatments if they detect leakage of fluid in the eye.
These treatments include photodynamic therapy (PDT - Novartis),
an injection of pegaptanib sodium into the eye (Macugen:
OSI/Pfizer) or the older treatment of thermal laser when
indicated. In addition the retinal specialist may also
discuss participation in a clinical trial with one of
the newer drugs such as Lucentis (Genentech). There are
numerous other treatments that may be investigational
as well as those that are controversial. It is recommended
that any new treatment or question about treatment be
discussed with your specialist.
The
only proven recommended treatment for the moderate and
advanced dry form of macular degeneration recommended
at this time is the AREDS formulary (Age-related Eye Disease
Study) of anti-oxidents and vitamins that include Vitamin
A, Vitamin C, Vitamin E, Zinc, and Copper. Again, it is
advisable to discuss any type of supplements with your
eye doctor especially if you were a smoker. The National
Eye Institute is running a new clinical trial that will
investigate the effectiveness of the addition of 10mg.
of Lutein as well as Omega III in slowing down the progression
of the dry as well as the wet form of disease.
What other
treatment is available if the vision continues to decrease?
A
low vision evaluation by an optometrist or ophthalmologist
will start the process of vision rehabilitation. The
low vision eye doctor, will find out your specific objectives,
use specialized eye charts and techniques in an examination
designed to make maximize use of your visual potential
as well as prescribe low vision devices that are specific
for your needs. One test, used in the evaluation, the
Amsler Grid is well known as a test to monitor any vision
changes by seeing whether the lines become distorted,
disappear, or whether the boxes get larger or smaller. 
Credit: National Eye Institute, National Institutes of
Health
Ref#:
EC03 Credit: National Eye Institute,
National Institutes of Health
Credit: National Eye Institute,
National Institutes of Health
Ref#:
EC04
The
low vision doctor will prescribe low vision devices that
include strong reading lenses (microscopic lenses), magnifiers,
telescopic system, absorptive lenses and filters, as well
as electronic magnifying devices. They may also recommend
additional vision rehabilitation services, including mobility
and modification of the home environment to enable one
to continue to pursue normal activities.
There
is exciting research in reducing, slowing down, as well
as in stopping the progression of age-related macular
degeneration. But you can you begin to decrease your
risk as well as improve your health? Here are 10 great
ways:
1.
Increase
your intake of leafy green vegetables and fruits.
2.
Start
exercising and become more fit.
3.
Increase
your intake of Omega III and fish discuss nutritional
supplements with your eye doctor
4.
Decrease
your BMI
5.
Monitor
your vision everyday if you have been diagnosed with AMD
6.
Don’t
buy over-the-counter glasses to save on an eye examination.
7.
Have
your eyes examined by an optometrist or ophthalmologist
8.
See
your eye doctor if there are any changes. There may be
a critical period to institute treatment
9.
Ask
your eye doctor whether you should be a low vision doctor
10.
And
stop smoking!!
Dr.
Bob Thompson, from the UK, was the first Chair of the
AMD Alliance International, and as he puts it, “a sufferer
of macular degeneration” since his early ‘50’s. He had
to stop practicing medicine but continues on in a role
of empowering people who have developed AMD. As Dr. Bob
says, to the statement that he heard over and over: “I
am sorry. There is nothing more that can be done for
you, are useless words that too many of us have heard from our
medical attendants in the early stages of our journey
through AMD. It isn’t true!” (From Living Well With Macular Degeneration, pub: NAL).
In
the meanwhile you too can take charge of your life as
well as live a more interesting and exciting life. It’s
up to you!
For
further information go to the following websites:
The
Lighthouse International website: http://www.Visionconnection.org
The
AMD Alliance International website at: http://www.amdalliance.org
