Glaucoma refers to a group of diseases that have common
features including a pressure in the eye (intraocular)
which is too high for the health of an individual eye,
damage to the eye's optic nerve, and visual field
(sight) loss. Most types of glaucoma affect both eyes at
the same time. There are usually no symptoms or warning
signs that glaucoma is present. However, early diagnosis
and treatment is the key to successfully managing
glaucoma and ideally occur before significant damage
In many ways we should think about glaucoma as we do
high blood pressure (hypertension). Neither disease
typically causes any symptoms and both harm our bodies
without our being aware it is happening. Both of these
diseases can cause severe problems if untreated . . .
glaucoma can cause partial or complete blindness and
high blood pressure can cause stroke and heart attack.
Glaucoma has been called the "sneak thief of sight"
because the typical glaucoma sufferer feels no pain or
discomfort and is unaware that vision is being lost
until the disease is very advanced with central vision
is affected. Unfortunately, by the time central vision
is affected a great deal of surrounding or peripheral
vision has already been lost. With the way our two eyes
and brain work we simply do not detect the early loses
of peripheral vision in glaucoma. The only way these
early changes are detected is through very sophisticated
testing from your eye doctor. While the overwhelming
majority ( perhaps 95 % ) of patients with glaucoma have
one of the common "silent" forms there are very rare
cases of "acute glaucoma" which occur with severe eye
pain, headache, and perhaps vomiting and the appearance
of "haloes" around lights. Any such severe eye problem
should cause you to immediately contact your eye doctor.
The front part of the eye is filled with a clear fluid
(aqueous humor). This fluid is continually produced
within the eye where it circulates and eventually drains
out. This fluid is what determines the eye's pressure
and it is easily measured by your eye doctor.
Glaucoma is commonly thought to be a disease of "high
eye pressures." There is certainly a level of pressure
which is felt to be too high to be considered acceptable
in any eye and as such would most likely be treated
whether or not any other risk factors are present.
However, it is important to stress that there is no
particular "pressure" at which a person automatically
has glaucoma. The pressure which your doctor measures in
your eyes is just one of the factors which must be
considered in deciding whether or not you have glaucoma.
Every person's eyes are different and depending upon
other factors such as your age, family history and
general health, a particular "pressure" which might not
be a problem for others might be too high for your eyes.
Quite simply the eye's pressure is determined by the
internal production and drainage of fluid which comprise
a basic "plumbing system." Like any "plumbing system" if
the drain becomes blocked or too much fluid is produced
for the "drain" to handle the system backs up and the
pressure inside goes up. If a pressure is determined to
be too high and is not reduced and maintained at a
healthy level for a particular individual it will
eventually damage the eye's optic nerve . . . the
pathway by which images are brought to the brain so that
"seeing" as we think of it can occur. Uncontrolled, this
damage can produce partial and even complete blindness.
The diagnosis of glaucoma involves much more than the
measurement of "eye pressures." The optic nerve is
carefully examined with various instruments and may well
be specially photographed to facilitate long term care.
The loss of any vision from glaucoma is evaluated and
recorded using highly sophisticated computerized visual
field testing instrumentation.
Once diagnosed glaucoma is treated aggressively with the
goal of stabilizing any vision loss which may have
occurred and preventing further damage. The first line
of therapy is usually the use of various medications in
the form of eye drops. These drops may have differing
specific affects from reducing fluid production within
the eye to enhancing its drainage. It may be that a
single type of drop has enough effect to adequately help
a given patient while other patients may require
multiple types of medication and changes over time. For
those patients for whom medication does not provide
adequate control of the disease there are various types
of surgery available, both traditional and laser, to
improve their condition.
It is important to recognize that glaucoma, like
diabetes and high blood pressure, requires lifelong
medical care and treatment. For the vast majority of
glaucoma sufferers, timely diagnosis and treatment allow
useful and satisfactory vision to be retained throughout
life. Glaucoma affects approximately 5 % of all elders
and occurs 5 - 6 times as often in Blacks as it does in
whites. It is important to remember that a family
history, parents, grandparents, brothers or sisters with
glaucoma, increases the likelihood that you may suffer
the same problem and so it is especially important to
obtain thorough yearly eye examinations.