Jargon Alert! What is AMD?
Your eyes depend upon a small spot (the macula) in the central
area of the retina located at the back of the eye for perceiving sharp
detail with straight-ahead vision.
Light from the objects that you view enter through the clear
portion of the eye, passing through the pupil and lens where it is
focused upon the light sensitive layer called the retina.
Your central, or macular, vision is what allows you to see well
enough to read, drive or perform other activities that require sharp
vision. Although most of
us have wide peripheral vision, it does not allow us to see detail as
well as with central vision. To
demonstrate the effect of the macula, choose a word in the middle of
one of the above sentences and focus exclusively upon that word.
With your focus remaining upon that word, use your peripheral
vision to see how many words on either side of it you can read
clearly. Most people
cannot read more than one or two short words on either side of that
point of focus.
AMD is an abbreviation for an eye disorder called
age-related macular degeneration.
AMD is painless, and its most common symptoms are pictures or
type become blurry and straight lines in your field of vision such as
telephone poles and the sides of buildings may appear wavy.
In more severe forms dark or empty spaces may block the center
of your vision. AMD is
the leading cause of visual impairment in persons aged 75 or older and
is the most common cause of new visual problems among those over age
65. Leaking blood vessels
under the macula causes the “wet” type of AMD whereas the slow
breakdown of the cells within the macula causes “dry” AMD.
In its most severe form, AMD can lead to total blindness.
In some families, AMD is more common and may also be associated
arteriosclerosis and eye trauma.
Some of the current research has focused on age-related
deposits, called drusen, that are similar in molecular composition to
plaques and deposits in other age-related diseases such as
Alzheimer’s disease and atherosclerosis. Having macular degeneration does not mean that you will
develop Alzheimer’s disease.
Scientists have established a strong link between
lutein, a carotenoid found in dark green leafy vegetables and a
reduced occurrence of AMD. Carotenoids
are powerful antioxidants that neutralize some damage forming
molecules and it is thought that lutein protects the eye by blocking
harmful blue light from reaching the back of the eye.
The diagnosis of AMD is made by inspecting the
eye by using a special scope to examine the retina and macula.
An Amsler grid may be used to detect blind spots or wavy lines
in vision. Currently
there are no definite treatments that prevent AMD but some researchers
believe that maintaining healthy blood pressure, not smoking and
wearing sunglasses that block out ultraviolet rays may help prevent
AMD. |
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