What is the Macula?
In the back of the eye is the retina which is analogous to the film of a
camera. One small area of the retina, called
the macula, is devoid of visible blood vessels and has the highest concentration
of photo-receptors (light capturing cells). This is the area of the retina
that accounts for visual acuity. The center of the macula is called the fovea. This
small area
of the retina is used when you look straight ahead. It is the area used to
drive a car, read a book, and watch television.
What is Macular Degeneration?
Unfortunately, this very biologically active tissue is prone to damage with
age. The disease is a degeneration process. It occurs more commonly in people that: are fair skinned, have
high blood pressure, exposed to
sunlight, smoke, and those without cataracts. There are two types of Age
Related Macular Degeneration (ARMD): dry and wet. Dry is a slow insidious
disturbance of the macular area with accompanying loss of vision. The dry
type occurs most of the time (most common 90% of the time). The
vision usually does not get very bad. The wet type is due to leakage
of fluids and blood under and within the macula. The effect is often devastating.
The wet type if caught early enough can be treated with a laser to seal the
leaky areas.
For therapy to be successful wet macular degeneration must be identified in
the early stages. Recently there have been a number of new treatments for wet
ARMD. These new treatments are made up of anti-VEGF (vascular epithelial
growth factors). These new drugs stop the formation of new, leaky blood vessesl
associated with wet macular degeneration. Current treatment includes the use of intravitreal
injection of Lucentis, off label
Avastin, Macugen, steroids and PhotoDynamicTreatment with
Visudyne (which is being used much less now). Use of these treatments
by itself or combination offers exciting opportunities in the treatment of this
destructive disease. These medications attempt to one of three things:
stop the development of new leaky blood vessels which cause leakage of fluid and
blood; reduction of inflammation; and destruction of leaky vessels. Treatment is costly
and may be needed to be repeated every 3 mos. but it is very promising for the right patients.
For the first time some patients with macular degeneration may have an improvement
in vision with treatment. Most patients who do not achieve improvement at
least stabilize their vision
The first sign of wet macular degeneration is a sudden distortion or wavy vision in one
eye. If this occurs, there is a small window of time in which fluid is
beginning to leak and a laser can stop the leakage with a minimum of damage.
Laser at best is not a cure but a method of stabilizing vision. In most
cases laser results in an initial decrease of vision, but compared to the
devastating, long term effects of wet macular degeneration this is a benefit.
Though, the dry form may also cause distortion the distortion is less severe and
more insidious in its development.
How is the Diagnosis Made?
The diagnosis of Age Related Macular Degeneration (ARMD) can only be made
with special instruments to examine the back of the eye known as the retina. Either
dry macular degeneration or significant wet macular degeneration may be
diagnosed by visual observation of the back of your eye during the dilation
portion of your eye examination. However, subtle wet macular degeneration
needs more sophisticated tests such as fluorescein angiography. Fluorescein
angiography is performed by injecting a dye into the arm and photographing the
passage of the dye through the arteries, capillaries and veins of the eye.
If there is any leakage of fluid by the blood vessels, the dye will leak out of
the vessels and be seen on the photographs taken during testing.
If
you notice a sudden change in your vision, particularly distortion of lines you
should make an immediate appointment.
How Common is ARMD (Age Related Macular
Degeneration) ?
There are many types of ARMD with variable visual out comes. It effects
20% of those between 65-75 and 35% of patients older. There is no cure for
ARMD, but there is help. Most cases are very mild with patients not even
being aware of the problem.
I Have the Dry Type Will I Get the Wet Type?
Most patients with dry ARMD remain that way for years. However,
patients with dry ARMD have a greater chance of developing the wet
variety. That is why we suggest that you check your vision in each eye
with the grid every day.
One of My Parents Has ARMD will I Get It?
There is a genetic predisposition to ARMD, thus, if your parents have it you
have a better chance of getting it. However, if your parents have it, it
doesn't mean you will get it. We have not identified the gene for ARMD and
do not know the mode of transmission.
Will I Go Blind From Macular Degeneration?
Fortunately, the visual loss though devastating does not cause complete
blindness. Peripheral vision is intact and mobility is maintained.
However, ARMD makes it difficult or impossible to drive, read, or watch
TV. Patients with
ARMD should evaluated for appropriate visual aids
to improve the quality of life. Special glasses (magnifiers and
telescopes) may be prescribed to
magnify the print. Computers can be designed to enlarge print. Special
viewing devices can enlarge print. Large print magazines and newspapers are available.
Obviously, these devices are not a cure, but they sure help. The patient
must be motivated to use them.
Do Vitamins Really Help?
Yes. Patients prone to ARMD should take
vitamins such as Ocuvite (PreserVision), Maxivision which contains zinc; Lutein , a
naturally occurring carotenoid; and Beta Carotene. Lutein is an
anti-oxidant which is believed to block the effects of UV light. These vitamins have been designed to
slow the progression of ARMD especially in the dry type.
The National Eye Institute, a division of the National Institute of
Health, released the results of an eight year study (JAMA Oct 2001). The
study was performed on close to 3500 particiapants between the ages of 55 and
80. The subjects were divided in four groups: no ARMD, early ARMD,
intermediate, and advanced ARMD. Subjects who were classified as having either
intermediate or advanced ARMD and used high potency anti-oxidants with zinc and
copper
showed a small but real decrease in the progression of ARMD. There
was no real effect with those patients who were in the no ARMD and early ARMD
groups. If you
are a smoker you should not take beta carotene, take zinc with copper only. Lutein was
not available at the time of the study. Thus, we believe that the judicious use of vitamins is more likely to be beneficial than
not.
Also, UV filters should be put in to all glasses used outside. These
glasses should be used even on a cloudy day, since UV light passes through the
clouds. Wearing a brimmed hat decreases further exposure to UV light. If you smoke
you should stop and control your blood pressure (the silent killer) and
cholesterol level.
What Should I Eat?
A diet beneficial for cardiovascular health is also good for the eyes - low
in saturated fats, high in fruits and vegetables. Exercise is also
important, since a healthy heart sends more nutrients and oxygen to the eyes. There is
also evidence that dark leafy vegetables such as spinach, kale, and collard
greens are helpful. A glass of red wine seems to be helpful.
Stop smoking!
I Can't Read With my Current Glasses, Can You Help?
Maybe yes, maybe no. We can only tell with an evaluation. Patients with
reduced vision can often benefit from special glasses which magnify the
print. This does not make it clearer but enlarges the print enough to
see. These special glasses include: stronger lenses, telescopes, and/or
microscopes. Strong hand held or table magnifiers may also be beneficial. Computer
screens can be adjusted to change the font. Large print magazines and
newspapers are available. Special closed circuit TV systems have been
designed to enlarge print. In summary, there is help for the motivated patient.
How Should I Monitor My Vision?
Print out this grid pattern. Put it on the
refrigerator or medicine cabinet. Look at it
each day, one eye at a time. If the lines become distorted then come in immediately for an
eye examination.
Instructions for using the grid
