|
Age-related macular degeneration (AMD) is now the
leading cause of vision loss among people over 65
in North America, Europe, and Japan. Eyesight’s
Macular Degeneration Center offers all available
therapies, including medical, surgical and laser
treatments.
The macula is the central portion of the
retina, which is the light sensitive tissue in
the back of the eye. It is responsible for the sharp,
central vision required for reading, driving, and
seeing fine details. When the macula is affected
by AMD, the change may be abrupt and very noticeable,
or so gradual that it is not noticed, especially
if only one eye is affected. Since AMD affects
only the central vision, complete blindness is not
a result of AMD.
The risk of developing AMD increases
with age. Those over 75 have a one in three chance
of developing the disease. In addition to age,
risk factors include smoking, obesity, being Caucasian,
being female, and having a family history of AMD.
Early
symptoms of macular degeneration may include blurred
distance vision, difficulty reading, a dark spot
in or near the central vision and distortion of
straight objects. Since AMD is painless and the vision
changes can be subtle, getting regular eye examinations
from your eye doctor is critical.
If AMD is suspected,
a comprehensive eye examination is the first step,
including a thorough history, slit lamp examination,
various forms of vision testing, as well as other
special tests to evaluate the macula. The latter
usually includes fluorescein angiography, a photographic
evaluation of the retinal circulation. In addition,
other imaging studies of the retina may be helpful.
There
are two forms of macular degeneration. Dry AMD,
the most common form, involves a slow, progressive
deterioration, often leading to atrophy of the macula.
Wet, or exudative AMD is responsible for 90% of the
vision loss associated with the disease. Wet AMD
is caused by the growth of new abnormal blood vessels
beneath the retina which frequently leak, bleed,
and form scar tissue which can destroy the overlying
retina. Wet AMD is considered to be advanced AMD
and is more severe than the dry form. Since the dry
form of AMD can progress to the wet form, dry AMD
should be monitored closely for signs of progression.
There is no way to predict if or when the dry form
of AMD will progress to the wet form. |
