Macular
Degeneration
Probably
the most common cause of diminished central vision in senior citizens
is macular degeneration. It's real title is Age Related Macular Degeneration
(ARMD). The macula is a small specialized area of the retina in
the back of the eye which is responsible for detailed vision and color
vision. When we thread a needle or read we use our macula.When there
is a degeneration of these specialized cells in and around the macula
our fine central vision becomes blurred and reading is especially difficult.
ARMD rarely, if ever, affects our peripheral vision.
There are two basic forms of ARMD.
The first, or DRY, form is by far the most common, accounting
for over 90% of all ARMD. Here, the central vision is very slowly blurred.
In the early phase it may be present, but the patient may be totally
unaware of any difficulty. It slowly progresses in most cases, but sometimes
remains stable for years without change.
The second, or WET, form is much different. It tends to
move quickly and significantly reduces vision within a few months to
a few years. It consists of new blood vessel formation under the retina.
These vessels leak fluid and blood thus distorting the macula and causing
a relatively fast reduction in central vision.The exact cause of ARMD
is unknown, although some believe that antioxidant vitamins and trace
minerals are helpful in slowing the process. There is as yet no definitive
proof of the value of this therapy for ARMD.The dry form may change
into the wet form at any time, or the wet form may begin on its own
without any warning. Monitoring vision with an Amsler grid is helpful
in knowing if the dry form is changing into the wet form.This is important
because the wet form in its early stages may be treatable with the LASER.
An angiogram of the retina is necessary to determine if LASER therapy
would be beneficial.
When no medical therapy is available increased illumination,
magnifying glasses, large print books, and talking books are helpful
in maintaining reading vision.One reassuring point about ARMD is that
it only affects the central few degrees of vision and that sufferers
can almost always take care of themselves and maintain useful ambulatory
vision.