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What is Macular Degeneration? This is the most common of
a number of degenerative conditions that can affect the retina.
Age Related Macular Degeneration (ARMD) is the most common form,
with problems typically not presenting until the 5th, 6th, 7th or
even the 8th decade of life. The macula is the central portion of
the retina with the densest concentration of the photo receptor
cells that allow vision, and it is the area that is responsible
for our sharp central vision. Unfortunately, this is the area that
is most profoundly affected in macular degeneration. Deterioration
and even total loss of central vision is the hallmark of ARMD. Macular degeneration is a
very common problem, and is the leading cause of blindness in older
adults. In its most advanced forms, the loss of central vision can
become so profound that a person is unable to read, drive, watch
TV, recognize a face, or even walk across a room without tripping
over things. The epidemiologists tell us that there are almost 5,000
new cases diagnosed each day and that by the year 2010 there will
be 30 million cases of ARMD in the United States alone. There are
some studies that suggest that almost one quarter (25%) of adults
over the age of 65 show some evidence of deterioration in the macular
region. There is no simple answer
to the question of what causes macular degeneration. There is strong
evidence that there is an important genetic component to this disease.
There are families where the disease is clearly passed from generation
to generation. There is a juvenile form of macular degeneration
called Stargardt's disease that appears to have similar genetic
abnormalities to those found in people with ARMD. As the science
of gene sequencing and the study of genetic disease has progressed
in the last ten years, there has been an ability to look at the
genes in the people with ARMD who do not have a clear family history
for the disease, and even here there is evidence for a genetic abnormality.
The gene that has been identified is named the ATP-binding cassette
transporter gene (ABCR). Abnormalities in this one gene are found
in age-related macular degeneration (ARMD), Stargardt's disease
(STGD) and fundus flavimaculatus (FFM), and in families with recessive
retinitis pigmentosa (RP), cone dystrophy (COD), and cone-rod dystrophy
(CRD). An article from Ophthalmic Genetetics, 1998 Sep;19(3):117-22
by van Driel MA, et.al. entitled ABCR unites what ophthalmologists
divide describes the common genetic link in what were once believed
to be different diseases. It seems that spontaneous abnormalities
occur commonly in this gene, which might explain the large numbers
of people who have no apparent family history of the disease. There are other factors that
influence the development of macular degeneration. Smoking, diet
and lifestyle, and the presence or absence of other health problems
involving the eye can have an effect on how early in life the disease
presents, and how severe the disease becomes. Smoking, diet, and
lifestyle habits alone do not cause macular degeneration, but they
are all factors that people have some control over, and if you are
worried about macular degeneration, it is certainly prudent to stop
smoking, eat well, exercise and take good care of the other aspects
of your health and well being. The underlying problem with macular degeneration probably involves the abnormal formation of proteins such as the ABCR protein discussed above that are needed in the membranes of the cells of the eye to allow proper functioning of these cells. 80% of the activity of any cell is concentrated in chemical reactions and metabolic activity at the region near the cell membrane, and improving the function of the cells at this level is the goal of microcurrent stimulation. In a sense, the problems with macular degeneration are rather trivial at the cellular level, for if the geneticists are correct, the underlying problem of macular degeneration is present from birth, yet symptoms do not even appear until a person is in their 60's, 70's or 80's. We have treated several professional airline pilots who had perfect vision at the age of 60 when they retired. As the disease progresses, however, all of the different types of cells in the retina are affected, including the connective tissues that hold everything together and the blood vessels. In its later stages, there is a decrease in blood flow to the retina, and this creates its own additional problems. As the disease progresses, the deterioration in the structure of the retina and the poor blood flow can result in bleeding or leakage from weakened and abnormal vessels. This is the condition known as exudative, or "wet" macular degeneration. The bleeding is a complication that occurs in macular degeneration, and both "wet" and "dry" macular degeneration are a spectrum of the same disease. Return to Macular Degeneration Home Page
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