macular degeneration (
AMD) affects the eyesight
of over 13 million Americans. In many cases, the onset of
AMD drastically limits ones’ mobility and devastates one’s sense of
independence and security. It strikes painlessly, disrupting the central
vision needed to read, write, drive and to
most often affects persons in their late fifties or sixties. An estimated
200,000 Americans develop a severe form of
each year, making it the leading cause of functional blindness in people
65 or older. One-third of the population over age 75 is likely to develop
This photo represents the way a person’s vision can be affected by macular
there is no known cure or lasting treatment for
and, until recently, it had been considered impossible to treat in any
form. However, new advances in eye research such as photodynamic therapy
offer hope to those whose lives have been affected by this disease or
in whom the disease is likely to develop.
AMD is a group of similar diseases that destabilize
the macula, a tiny section of the retina in the back of the eye. The
retina is a paper thin tissue that receives images and converts them
into electrical signals sent to the brain through the optic nerve.
The retina contains two forms of light-receiving cells called rods and
cones. The macula, which is about the size of a pinhead, is rich in
cone cells which give us our color and central vision. Rod cells help
us to see at night.
are two main types of macular degeneration – the “dry” type and the
“wet” type. In either case, the disease leaves peripheral vision intact
and most of those afflicted retain some usuable
“dry” or atrophic form accounts for 9 out of
“wet” or exudative form occurs in only 1 in
10 cases of A
MD but it causes about 90 percent
of the cases of sever visual loss. In “wet”
abnormal blood vessels develop rapidly under the retina and leak blood
or fluid that damage the macula causing sever and sometimes sudden vision
loss. The wet form often results in the growth of dense scar tissue.
exact cause of
AMD is unknown but it is almost
always age-related and the incidence is higher in women than in men.
Although it is not an inherited disease in the classic sense,
may be clustered in some families. The condition is more prevalent
among Caucasians and appears to be most common in people with blue or
light-colored eyes. Additional risk factors may include, among others,
hypertension, smoking and excessive exposure to ultraviolet (UV) rays,
especially from the sun.
over 50, especially those with a family history of
should have their eyes examined regularly by their eye doctor and should
use the Amsler grid at home. Below is an Amsler Grid and what it might
look like to someone with AMD.
is usually painless. The “dry” type can be very slow in forming, but
the “wet” type is likely to develop quickly and may cause sudden visual
loss or distortion. In some cases, the disease develops in one eye
but does not affect the other for many years. Symptoms vary and may
A blurring of printed words
Gradual development of blind spots in the center of the field of vision
Difficulty in picking out details, near and far
Straight lines appearing to be wavy and shapes distorted
Dimmed color vision
eye doctor can detect early signs of AMD through a regular eye examination
which might include the use of an Amsler grid. To a person with
the straight lines of the grid may appear to be wavy.
AMD BE TREATED?
advances in eye research offer new hope to victims of
In a small percentage of people with wet
AMD, laser photocoagulation therapy can be used to destroy abnormal
blood vessels and to seal leaks, thereby retarding the progression of
treatment is usually a painless outpatient procedure, but even if the
treatment succeeds in slowing the rate of vision loss, the laser may
leave permanent blind spot where it has been applied. In effect, the
individual may lose some sight in order to slow the disease and extend
the use of the remaining central vision. Nonetheless, recurrence of
new vessels and leakage are common even after laser therapy.
compound, verteporfin, slow or halts the wet
(and most sever) form of
AMD. Verteporfin is a photosensitive dye used in a laser procedure called photodynamic
therapy (PDT). Injected intravenously, the dye travels to the retina
where it is then activated by shining a low intensity laser onto the
damaged area. This causes a chemical reaction which destroys the abnormal
vessels. PDT can retard visual deterioration in about half of those
treated by clearly does not cure the disease. The treatment must be
no proven treatment exists for the dry form of
However, researchers have discovered that a healthy macula has two yellowish
pigments – the antioxidants known as lutein and zeaxanthin – they may
block harmful blue light from damaging the retina. Studies suggest
that nutritional supplements containing these antioxidants may slow
The Food and Drug Administration (FDA) today approved Lucentis (ranibizumab injection)
for the treatment of patients with neovascular
(wet) age-related macular degeneration (AMD). Lucentis
is the first treatment which, when dosed monthly, can maintain the vision
of more than 90 percent of patients with this type of AMD. Lucentis
is a new molecular entity (NME), meaning it contains an active substance
that has never before been approved for marketing in any form in the
approval is of great importance for the 155,000 Americans who are diagnosed
each year with AMD, a common cause of severe and irreversible vision
loss in older adults," said Dr. Andrew von Eschenbach,
Acting Commissioner of Food and Drugs. "At a time when our elderly
population is rapidly increasing, this product preserves quality of
life for those affected by this disease, helping them to regain the
ability to participate in everyday activities such as reading and driving."
AMD BE PREVENTED?
one knows how to prevent
AMD but the following
practices may help to delay the onset of the disease.
a proper diet including fruits & vegetables right in antioxidants,
especially leafy green vegetables such as spinach and collard greens.
sunglasses and brimmed hats to avoid excessive UV exposure
smoke since smoking reduces the protective antioxidants in the eye
WITH VISION LOSS
a cure or lasting treatment fro
AMD is found,
patients should consult an eye doctor and a low vision specialist for
advice about products and rehabilitation techniques to maximize remaining
vision. There are many resources services available to help cope with
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