What is glaucoma?
Glaucoma is a disease of the optic nerve —
the part of the eye that carries the images
we see to the brain. The optic nerve is made
up of many nerve fibers, like an electric
cable containing numerous wires. When damage
to the optic nerve fibers occurs, blind
spots develop. These blind spots usually go
undetected until the optic nerve is
significantly damaged. If the entire nerve
is destroyed, blindness results.
Early detection and treatment by your
ophthalmologist are the keys to
preventing optic nerve damage and blindness
from glaucoma.
Glaucoma is a leading cause of blindness in
the United States, especially for older
people. But loss of sight from glaucoma can
often be prevented with early treatment.
What
causes glaucoma?
Clear liquid called aqueous humor circulates
inside the front portion of the eye. To
maintain a healthy level of pressure within
the eye, a small amount of this fluid is
produced constantly while an equal amount
flows out of the eye through a microscopic
drainage system. (This liquid is not part of
the tears on the outer surface of the eye.)
Because the eye is a closed structure, if
the drainage area for the aqueous humor —
called the drainage angle — is blocked, the
excess fluid cannot flow out of the eye.
Fluid pressure within the eye increases,
pushing against the optic nerve and causing
damage.
What are
the different types of glaucoma?
Chronic
open-angle glaucoma:
This is the most common form of glaucoma in
the United States.
The risk of developing chronic open-angle
glaucoma increases with age. The drainage
angle of the eye becomes less efficient over
time, and pressure within the eye gradually
increases, which can damage the optic nerve.
In some patients, the optic nerve becomes
sensitive even to normal eye pressure and is
at risk for damage. Treatment is necessary
to prevent further vision loss.
Typically, open-angle glaucoma has no
symptoms in its early stages and vision
remains normal. As the optic nerve becomes
more damaged, blank spots begin to appear in
the field of vision. You typically won't
notice these blank spots in your day-to-day
activities until the optic nerve is
significantly damaged and these spots become
large. If all the optic nerve fibers die,
blindness results.
Closed-angle glaucoma:
Some eyes are formed with the iris (the
colored part of the eye) too close to the
drainage angle. In these eyes, which are
often small and farsighted, the iris can be
sucked into the drainage angle and block it
completely. Since the fluid cannot exit the
eye, pressure inside the eye builds rapidly
and causes an acute closed-angle attack.
Symptoms may include:
* blurred vision;
* severe eye pain;
* headache;
* rainbow-colored halos around lightsl
* nausea and vomiting
This is a true eye emergency. If you have
any of these symptoms, call your
ophthalmologist immediately. Unless this
type of glaucoma is treated quickly,
blindness can result.
Unfortunately, two-thirds of those with
closed-angle glaucoma develop it slowly
without any symptoms prior to an attack.
Who is at
risk for glaucoma?
Your ophthalmologist considers many kinds of
information to determine your risk for
developing the disease.
The most important risk factors include:
* age;
* elevated eye pressure;
* family history of glaucoma;
* African or Spanish-American ancestry;
* farsightedness or nearsightedness;
* past eye injuries;
* thinner central corneal thickness;
* systemic health problems, including
diabetes, migraine headaches, and poor
circulation.
Your ophthalmologist will weigh all of these
factors before deciding whether you need
treatment for glaucoma, or whether you
should be monitored closely as a glaucoma
suspect. This means your risk of developing
glaucoma is higher than normal, and you need
to have regular examinations to detect the
early signs of damage to the optic nerve.
How is
glaucoma detected?
Regular eye examinations by your
ophthalmologist are the best way to detect
glaucoma. A glaucoma screening that checks
only the pressure of the eye is not
sufficient to determine if you have
glaucoma. The only sure way to detect
glaucoma is to have a complete eye
examination.
During your glaucoma evaluation, your
ophthalmologist will:
* measure your intraocular pressure (tonometry);
* inspect the drainage angle of your eye (gonioscopy);
* evaluate whether or not there is any optic
nerve damage (ophthalmoscopy);
* test the peripheral vision of each eye
(visual field testing, or perimetry).
Photography of the optic nerve or other
computerized imaging may be recommended.
Some of these tests may not be necessary for
everyone. These tests may need to be
repeated on a regular basis to monitor any
changes in your condition.
How is
glaucoma treated?
As a rule, damage caused by glaucoma cannot
be reversed. Eyedrops, laser surgery and
surgery in the operating room are used to
help prevent further damage. In some cases,
oral medications also may be prescribed.
With any type of glaucoma, periodic
examinations are very important to prevent
vision loss. Because glaucoma can progress
without your knowledge, adjustments to your
treatment may be necessary from time to
time.
Medications
Glaucoma is usually controlled with eye
drops taken daily. These medications lower
eye pressure, either by decreasing the
amount of aqueous fluid produced within the
eye or by improving the flow through the
drainage angle.
Never change or stop taking your medications
without consulting your ophthalmologist. If
you are about to run out of your medication,
ask your ophthalmologist if you should have
your prescription refilled. Glaucoma
medications can preserve your vision, but
they also may produce side effects. You
should notify your ophthalmologist if you
think you may be experiencing side effects.
Some eye drops may cause:
* a stinging or itching sensation;
* red eyes or redness of the skin
surrounding the eyes;
* changes in pulse and heartbeat;
* changes in energy level;
* changes in breathing (especially with
asthma or emphysema);
* dry mouth;
* changes in sense of taste;
* headaches;
* blurred vision;
* change in eye color.
All medications can have side effects or can
interact with other medications. Therefore,
it is important that you make a list of the
medications you regularly take and share
this list with each doctor you see.
Laser
Surgery
Laser surgery treatments may be recommended
for different types of glaucoma.
In open-angle glaucoma, the drain itself is
treated. The laser is used to modify the
drain (trabeculoplasty) to help control eye
pressure.
In closed-angle glaucoma, the laser creates
a hole in the iris (iridotomy) to improve
the flow of aqueous fluid to the drain.
Surgery in
the Operating Room
When surgery in the operating room is needed
to treat glaucoma, your ophthalmologist uses
fine, microsurgical instruments to create a
new drainage channel for the aqueous fluid
to leave the eye. Surgery is recommended if
your ophthalmologist feels it is necessary
to prevent further damage to the optic
nerve. As with laser surgery, surgery in the
operating room is typically an outpatient
procedure.
We also offer state-of-the-art glaucoma
treatment using ECP.
What is
your part in treatment?
Treatment for glaucoma requires teamwork
between you and your doctor. Your
ophthalmologist can prescribe treatment for
glaucoma, but only you can make sure that
you follow your doctor's instructions and
take your eyedrops. Once you are taking
medications for glaucoma, your
ophthalmologist will want to see you more
frequently. Typically, you can expect to
visit your ophthalmologist every three to
four months. This will vary depending on
your treatment needs.
Loss of
vision can be prevented
Regular medical eye exams may help prevent
unnecessary vision loss. Recommended
intervals for eye exams are:
* Age 20-29: Individuals of African descent
or with a family history of glaucoma should
have an eye examination every three to five
years. Others should have an eye exam at
least once during this period.
* Age 30 -39: Individuals of African descent
or with a family history of glaucoma should
have an eye examination every two to four
years. Others should have an eye exam at
least twice during this period.
* Age 40-64: Every two to four years.
* Age 65 or older: Every one to two years.
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