medication therapy. Surgical treatments for glau-
coma include the following:
- For iridotomy, the ophthalmologist uses an
ophthalmologic laser to place a small opening
in the iris. The opening provides another route
of drainage for the aqueous humor and helps
keep the iris from blocking the drainage angle
in open-angle glaucoma. - For trabeculoplasty,the ophthalmologist uses
an ophthalmologic laser to make numerous
“dots” in the trabecular meshwork—the fanlike
network of tiny channels at the end of the
angle that disperse the draining aqueous
humor—to expand its the draining capacity. - For trabeculotomy, the ophthalmologist places
an aqueous shunt, a tiny opening from the
anterior chamber through the sclera, to allow
aqueous humor to drain to the outside of the
eye. - For cytophotocoagulation, the ophthalmologist
uses an ophthalmologic laser to destroy por-
tions of the ciliary processes to reduce aqueous
humor production.
Early diagnosis and treatment offer the best
opportunity for minimizing vision loss. It is impor-
tant to diligently follow the directions for using
glaucoma medications, as glaucoma requires con-
sistent control. Appropriate treatment can slow
the progression of vision loss in most people who
have glaucoma.
Risk Factors and Preventive MeasuresAge is the most significant risk factor for glau-
coma; glaucoma is uncommon in people under
age 40 and about two thirds of people who
develop glaucoma are over age 65. Glaucoma is
more common in people of African American and
Asian ethnicity and tends to run in families. Glau-
coma also is more likely to develop in people who
have hypertension, ATHEROSCLEROSIS, diabetes, and
severe MYOPIA (nearsightedness) and in people
who take CORTICOSTEROID MEDICATIONS. Prevention
focuses on regular ophthalmic examinations to
detect glaucoma early in its course.
See also AGE-RELATED MACULAR DEGENERATION
(ARMD); CATARACT; LASER SURGERY; VISION HEALTH.
Graves’s ophthalmopathy Changes in the EYE
that occur as a result of Graves’s disease, a form of
HYPERTHYROIDISM, and occasionally as a result of
other forms of thyroid disease. The most promi-
nent feature of Graves’s ophthalmopathy is EXOPH-
THALMOS, an outward bulging or protrusion of the
eyes that often is the first indication of Graves’s
disease. The exophthalmos results from enlarged
extraocular muscles (the muscles that move the
eye) and edema (swelling due to retained fluid) in
the tissues around the eye and within the ocular
orbit (eye socket). This circumstance restricts the
ability to move the eyes, particularly upward and
side to side, as well as to close the eyelids. Graves’s
ophthalmopathy can involve only one eye (unilat-
eral) though most often involves both eyes (bilat-
eral). Symptoms and consequences range from
mild to severe, with about 5 percent of people
experiencing substantial loss of vision that may
include loss of the eye. Graves’s ophthalmopathy
can appear before there are any indications of
Graves’s disease, at the onset of hyperthyroid
symptoms, or months to years after the diagnosis
of Graves’s disease.
Graves’s ophthalmopathy presents a significant
threat to vision. The swelling in and around the
orbit pressures the structures of the eye and can
compress the OPTIC NERVE, which can result in OPTIC
NERVE ATROPHY (the death of cells in the optic
NERVE) and permanent VISION IMPAIRMENT. The
external pressure against the eye also raises the
pressure inside the eye (INTRAOCULAR PRESSURE),
which can result in GLAUCOMA. The combination of
exophthalmos and restricted lid movement pre-
vents the eyelids from closing completely, which
allows the CORNEAto become dry. The resulting
irritation and INFLAMMATION (KERATITIS) reduces
VISUAL ACUITYand also exposes the inner eye to
INFECTION. Though the symptoms that threaten
vision eventually subside, many of the changes
that result, including exophthalmos and vision
impairment, are permanent.
Symptoms and Diagnostic Path
The symptoms of Graves’s ophthalmopathy
include- exophthalmos (sometimes called poptosis)
- DIPLOPIA(double vision)
94 The Eyes