The most scary thing about glaucoma is that it can steal your vision gradually
and without your noticing. The best defense against glaucoma is a regular eye
examination. Glaucoma most often strikes people over age 50. But it is recommended
that during adult life everyone be tested at least every two years.
Some people with glaucoma do experience symptoms, but symptoms vary depending
on the type of glaucoma.
Primary open-angle glaucoma
By far the most common type, primary open-angle glaucoma develops gradually
and painlessly. Since there are no early warning signs, it can slowly destroy
your vision without your knowing it. The first indication may only occur after
some considerable vision loss.
Acute angle-closure glaucoma
This results from a sudden blockage of the drainage channels within your eye,
causes a rapid build-up of pressure inside your eye accompanied by blurred vision,
the appearance of colored rings around lights and sometimes extreme pain or
redness in the eyes.
What is glaucoma?
The build-up of pressure inside your eye leads to glaucoma.
Aqueous fluid, which fills the space at the front of the eye just behind the
cornea, is made behind the iris (the colored part of the eye) in the ciliary
body. It flows through the pupil (the dark hole in the center of the iris),
and drains from the 'anterior chamber angle,' which is the junction between
the edge of the iris and the cornea. If this outflow of liquid is impaired at
all, there is a build-up of pressure inside the eye that damages the optic nerve,
which carries visual images to the brain. The result is a loss of peripheral
vision. Thus, while glaucoma sufferers may be able to read the smallest line
on the vision test, they may find it difficult to move around without bumping
into things or to see moving objects to the side.
What causes glaucoma?
Some causes are known, others are not. Causes differ depending
on the type of glaucoma. The exact cause of open-angle glaucoma, where the drainage
channels for the aqueous appear to be open and clear, is not known. Closed-angle
glaucoma can occur when the pupil dilates or gets bigger and bunches the iris
up around its edge, blocking the drainage channel. An injury, infection or tumor
in or around the eye can also cause internal eye pressure to rise either by
blocking drainage or displacing tissues and liquid within the eye. A mature
cataract also can push the iris forward to block the drainage 'angle' between
the iris and the cornea. Glaucoma can occur secondarily to a number of other
conditions, such as diabetes, or as a result of some medications for other conditions.
Who gets glaucoma?
Glaucoma most frequently occurs after age 40, but can occur at any age.
If you're of African heritage, you are more likely to develop open-angle glaucoma
-- and at an earlier age -- than if you're Caucasian. Asians are more likely
to develop narrow-angle glaucoma.
You have a higher risk of developing glaucoma if a close family member has
it or if you have high blood pressure or high blood sugar (diabetes). There
is also a greater tendency for glaucoma to develop in individuals who are nearsighted.
Those at heightened risk for glaucoma should have their eyes checked at least
once a year.
Why is glaucoma harmful to vision?
The optic nerve, located at the back of the eye, carries visual
information to the brain. As the fibers that make up the optic nerve are damaged
by glaucoma, the amount and quality of information sent to the brain decreases
and a loss of vision occurs.
Will I go blind from glaucoma?
If diagnosed at an early stage, glaucoma can be controlled
and little or no further vision loss should occur. If left untreated, side awareness
(peripheral vision) and central vision will be destroyed and blindness may occur.
How is glaucoma detected?
Tests for glaucoma are part of a comprehensive eye examination.
A simple and painless procedure called tonometry measures the internal pressure
of your eye. Ophthalmoscopy examines the back of the eye to observe the health
of the optic nerve. A visual field test, a very sensitive test that checks for
the development of abnormal blind spots, may also be completed.
How is glaucoma treated?
Glaucoma is usually treated with prescription eye drops and
medicines. In some cases, surgery may be required to improve drainage. The goal
of the treatment is to prevent loss of vision by lowering the pressure in the
eye.
Will my vision be restored after treatment?
Unfortunately, any vision loss as a result of glaucoma is permanent and cannot
be restored. This is why regular eye examinations are important.
Glaucoma cannot be prevented, but early detection and treatment can control
glaucoma and reduce the chances of damage to the eye and a loss of sight. | 