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Primary Open-Angle Glaucoma
Chronic glaucoma, also known
as primary open-angle
glaucoma or POAG, often is
called "the silent thief of
sight" because you have no
warning sign, no pain and no
hint that anything is wrong.
About half of Americans with
chronic glaucoma don't even
know they have it.
In open-angle glaucoma, the
fluid in the eye's front
(anterior) chamber between
the clear cornea and the
colored iris (aqueous humor)
can't filter through an area
where it needs to pass
(filtration angle). This
occurs because the drainage
channels (trabecular
meshwork) are blocked,
causing internal eye
pressure (IOP) to rise.
As IOP increases, the
pressure pushes harder
against the nerve fibers of
the optic nerve, which
transmits images to the
brain. This increased
pressure reduces the blood
supply to the optic nerve,
depriving it of oxygen and
nutrients. Over time, high
IOP can cause irreversible
optic nerve damage and
vision loss.
Risk factors for chronic or
open-angle glaucoma include:
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Age. Your risk
for developing
open-angle glaucoma
increases significantly
after age 40 and
continues to increase
with each additional
decade. Aging also can
cause drainage channels
in the trabecular
meshwork to shrink or
narrow, which slows the
outflow of fluid from
the eye.
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Certain medical
problems. Diabetes,
extreme nearsightedness
and previous eye surgery
are risk factors for
chronic open-angle
glaucoma. If you have a
condition that requires
the use of oral or
inhaled steroids,
particularly high doses
for prolonged periods,
this can increase your
risk as well. Other
medical conditions
related to glaucoma
include migraine
headaches, high blood
pressure, narrowed blood
vessels (vasospasm) and
cardiovascular disease.
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Eye abnormalities.
Certain abnormalities
affecting internal eye
structures can cause
glaucoma.
Pseudoexfoliation
syndrome causes proteins
in the eye's natural
lens, iris and other
structures to slough off
and clog the eye's
drainage system.
Glaucoma also can result
when a misshapen iris
blocks the filtration
angle where drainage
occurs.
-
Race. Chronic
glaucoma is three to
four times more common
in African-Americans
than in whites. Also,
African-Americans are
more likely to develop
an aggressive form of
the disease at a younger
age.
-
Family history.
Your risk of developing
open-angle glaucoma may
be three to four times
higher if one or more of
your parents and
siblings have the
disease.
Chronic glaucoma gradually
reduces your peripheral
vision. But by the time you
notice it, permanent damage
may have already occurred.
If your IOP remains high,
the damage can progress
until significant loss of
your peripheral vision
develops, and you will be
able to see only objects
that are straight ahead.
As with other forms of
glaucoma, your treatment
options may include topical
glaucoma eye drops. Laser
and/or nonlaser glaucoma
surgery may also be
recommended as a way to
control IOP
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