|
Glaucoma refers to a
group of eye diseases that have common features, including elevated
eye pressure, damage to the optic nerve and vision loss. There are
many types of glaucoma. Infantile glaucoma is the term used for
glaucoma diagnosed in infancy or early childhood.
Childhood glaucoma is
associated with physical changes in the eye which are caused by the
high pressure. The increased fluid pressure can push on the optic
nerve and cause an abnormal enlargement in the central optic disc
area. If the pressure remains too high for too long the optic nerve
fivers are damaged. Enlargement of the eye, cloudiness of the cornea
and injury to the optic nerve are examples of changes that can occur
as a result of glaucoma.
Normal Anatomy
The sclera is
the white of the eye covered by a thin membrane called the
conjunctiva. The front of the eye consists of the cornea,
which is the clear part of the eye continuous with the sclera that
allows light to enter. The iris is the colored part of the eye,
at the center of which is the pupil (it appears black) that can
shrink and expand depending on the amount of light present. Behind the
iris and pupil is the lens which focuses the light onto the
retina, lining the back wall of the eye.
The front of the eye is
filled with a watery fluid called the aqueous humor. The fluid
is in a constant state of simultaneous production and absorption. The
fluid is absorbed by the trabecular meshwork.
The pressure of the
fluid inside the eye (the intraocular pressure or IOP) depends on this
rate of production and absorption.
Causes of glaucoma
There are many possible
causes for the drainage problem that results in childhood glaucoma. In
each case, abnormal fluid drainage from the eye is the result of a
blocked or defective trabecular meshwork drainage system. The defect
may be primary, or not associated with other eye defects. Primary
glaucoma may be due to a hereditary defect or caused by a
non-hereditary event during development. In other cases an abnormal
drainage system may be a result of some other disease activity in the
eye which results in secondary glaucoma. In these cases, the glaucoma
may be associated with recognizable iris, corneal, or other problems
Signs and Symptoms
Many cases begin with
little or no symptoms. There is usually a gradual onset of problems
that include light sensitivity (photophobia), opacification of the
normally clear cornea, overflow of tears (epiphora) and vision loss.
In addition, the eye can begin to enlarge from the increased pressure;
this may be noticed in photographs. Other signs can include
irritability, loss of appetite and vomiting. There is probably no
pain.
Diagnosis
The diagnosis of
glaucoma is made after careful examination by an ophthalmologist. This
may include a lengthy office visit. If the child is too young, this
examination may have to be carried out in the operating room with the
aid of general anesthesia. The parent will likely be asked to help
comfort, encourage and sometimes help restrain their child. These
exams may need to be repeated on a frequent basis.
Treatment
Medical treatment
involves the use of medicines. They can be in the form of eye drops or
oral preparations. These medicines either decrease the production of
fluid inside the eye or help to increase its exit from the eyes.
Surgical treatment is
almost always required in childhood glaucoma. Microsurgical techniques
are used to open the drainage channel in the eye. Depending on the
clarity of the cornea this will be accomplished by an incision in the
white of the eye (trabeculotomy) or by a direct incision into the
canal via the cornea (goniotomy). If these techniques fail, they can
be repeated, or other surgical treatments including lasers and
implantable drainage valves can be used. Multiple surgeries are not
uncommon. The success rate of these surgeries varies on the age of the
patient and the severity of the disease. A definite treatment plan and
prognosis varies in each individual case and is not the same for every
patient.
Note
Much of the information
above was obtained from a publication entitled, “Childhood Glaucoma, A
Reference Guide for Families,” published by the Glaucoma Research
Foundation. For a copy of this brochure please contact:
Glaucoma Research
Foundation
200 Pine Street, Suite 200
San Francisco, CA 94104
800-826-6693
www.glaucoma.org
 |
