Age-related
macular degeneration (ARMD) is a
degenerative condition of the macula (the
central retina). It is the most common cause
of vision loss in those 50 or older, and its
prevalence increases with age. AMD is caused
by hardening of the arteries that nourish
the retina. This deprives the sensitive
retinal tissue of oxygen and nutrients that
it needs to function and thrive. As a
result, the central vision deteriorates.
This
example demonstrates what a patient with
advanced macular degeneration sees. Macular
degeneration varies widely in severity. In
the worst cases, it causes a complete loss
of central vision, making reading or driving
impossible. For others, it may only cause
slight distortion. Fortunately, macular
degeneration does not cause total blindness
since it does not affect the peripheral
vision.
AMD is classified as either wet (neovascular)
or dry (non-neovascular). About 10% of
patients who suffer from macular
degeneration have wet AMD. This type occurs
when new vessels form to improve the blood
supply to oxygen-deprived retinal tissue.
However, the new vessels are very delicate
and break easily, causing bleeding and
damage to surrounding tissue.
.
Patient
with wet macular degeneration
develop new blood vessels under the
retina. This causes hemorrhage,
swelling, and scar tissue but it can
be treated with laser in some cases.
Dry
macular degeneration, although more
common, typically results in a less
severe, more gradual loss of vision.
The dry
type is much more common and is
characterized by drusen and loss of
pigment in
the retina. Drusen are
small, yellowish deposits that
form
within the layers of the retina.
Macular degeneration may be
caused by variety of factors including
genetics, age, nutrition, smoking, and
sunlight exposure.
SIGNS AND SYMPTOMS
Loss of central vision, This may be
gradual for those with the dry type.
Patients with the wet type may
experience a sudden decrease of the
central vision
Difficulty reading or performing
tasks that require the ability to
see detail
Distorted vision (Straight lines
such as a doorway or the edge of a
window may appear wavy or bent.)
DIAGNOSIS:
Eye physicians usually
diagnose AMD. Vision testing, Amsler grid
test, ophthalmoscopy, fundus photography and
fluorescein angiography are some common
tests performed during a retinal exam.
TREATMENT:
There
is no proven medical therapy for dry macular
degeneration. In selected cases of wet
macular degeneration, laser photocoagulation
is effective for sealing leaking or bleeding
vessels. Unfortunately, laser
photocoagulation usually does not restore
lost vision, but it may prevent further
loss.
Recently, photodynamic therapy has proven to
be effective in stopping abnormal blood
vessel growth in some patients with wet AMD.
This new type of laser treatment is far less
damaging than laser photocoagulation and is
the treatment of choice in many cases.
Early
diagnosis is critical for successful
treatment of wet macular degeneration.
Patients can help the doctor detect early
changes by monitoring vision at home with an
Amsler grid.
Several recent studies have indicated a
strong link between nutrition and the
development of macular degeneration. It has
been scientifically demonstrated that people
with diets high in fruits and vegetables
(especially leafy green vegetables) have a
lower incidence of macular degeneration.
More studies are needed to determine if
nutritional supplements can prevent
progression in patients with existing
disease.
If
you have been diagnosed with AMD, making a
few simple lifestyle changes could have a
positive impact on the health of your
retina.
Monitor your vision daily with an
Amsler grid. By checking your vision
regularly, changes that may require
treatment can be detected early.
Take a multi-vitamin with zinc.
(check with your eye physician for a
recommendation) Antioxidants, along
with zinc and lutein are essential
nutrients, all found in the retina.
It is believed that people with AMD
may be deficient in these nutrients.
Incorporate dark leafy green
vegetables into your diet. These
include spinach, collard greens,
kale and turnip greens.
Always protect your eyes with
sunglasses that have UV protection.
Ultraviolet rays are believed to
cause damage to the pigment cells in
the retina.
Quit smoking. Smoking impairs the
body's circulation, decreasing the
efficiency of the retinal blood
vessels.
Exercise regularly. Cardiovascular
exercise improves the body's overall
health and increases the efficiency
of the circulatory system.
To make reading easier, use a
halogen light. These have less glare
and disperse the light better than
standard light bulbs.
Shine the light directly on your
reading material. This improves the
contrast and makes the print easier
to see.
Use a hand-held magnifier drugstore
magnifier can increase the print
size dramatically.
Try large-print or audio books. Most
libraries and bookstores have
special sections reserved for these
books.
Consult a low vision specialist.
These professionals are specially
trained to help visually impaired
patients improve their quality of
life. After a personalized
consultation, they can recommend
appropriate magnifiers, reading
aids, practical tips, and many
resources.
Amsler Grid
Use a bright reading light
Hold the chart approximately 14-16
inches from your eye
This
example demonstrates what a patient with
advanced macular degeneration sees. Macular
degeneration varies widely in severity. In
the worst cases, it causes a complete loss
of central vision, making reading or driving
impossible. For others, it may only cause
slight distortion. Fortunately, macular
degeneration does not cause total blindness
since it does not affect the peripheral
vision.
