|
When treatment with eye drops, pills, or laser surgery does not
lower intraocular pressure to a safe level, your ophthalmologist may
determine that glaucoma surgery should be performed. One way to
reduce pressure in an eye with glaucoma is to make a new drain in
the eye. This type of surgery is called a trabeculectomy.
During this operation, a tiny piece of the wall of the eye, which
may include the trabecular meshwork (the natural drain), is removed
by the surgeon. This opens a new drain which creates a bypass for
the trabecular meshwork to reduce eye pressure. The eye pressure is
reduced because fluid can now drain with relative ease through the
new opening into a reservoir (bleb) underneath the conjunctiva
(which comprises the surface of the eye). The fluid is then absorbed
by the body.
The goal of trabeculectomy is to lower eye pressure. By lowering
eye pressure, it is hoped that the operated eye will be spared
further glaucoma damage and can maintain its vision. Although vision
sometimes can improve following trabeculectomy, in most eyes it
remains unchanged. Occasionally, there can be loss of vision.
What do I need to do before a trabeculectomy?
Eye
drops and pills which are being used to lower intraocular pressure
are continued until the time of surgery unless directed otherwise by
your ophthalmologist. Occasionally, an eye drop or pill may be
discontinued for as long as two weeks before the surgery. It is
particularly important to discontinue the use of aspirin, or any
pills containing aspirin, at least 7 days before surgery, since use
of aspirin can cause undesirable bleeding at the time of surgery.
What type of anesthesia is used?
To relax the
patient and reduce discomfort, a trabeculectomy is usually done
under local anesthesia. An injection of local anesthetic through the
eyelid numbs the eye completely so that it will not move during
surgery, and there is no discomfort. Sometimes a general anesthetic
is used, in which the patient is put to sleep for the operation.
Local anesthesia offers several advantages. There may be less pain
after surgery, and there is no sore throat from the airway tube used
in general anesthesia. Patients quickly return to normal alertness
without the nausea often felt after general anesthesia. With local
anesthesia, there is less risk than with a general anesthetic,
especially in the elderly or those with health problems. The surgery
itself takes less than one hour in most cases.
What happens to the eye after a trabeculectomy?
After trabeculectomy, the eye generally is covered by an eye
patch and protected by a plastic shield overnight. On the morning
following the surgery, it is removed and the eye is examined by your
ophthalmologist. Eye drops are then prescribed to relax the muscles
in the eye, prevent infection, and reduce inflammation.
Occasionally, a pill may be prescribed, as well, to further reduce
inflammation. It is important to take these as directed by your
ophthalmologist since they can make a great deal of difference in
the success of the procedure.
For several weeks following the surgery, your ophthalmologist
will observe your eye closely and examine you frequently. During
this time, the eye may have a very low pressure and be unstable. It
is important to protect the eye and avoid lifting heavy objects,
bending or straining. Your ophthalmologist may prescribe a cough
suppressant if you have a cough or a stool softener to ease bowel
movements. In addition, it is important to keep the eye clean and
dry since the eye may be susceptible to infection immediately after
the surgery. Your ophthalmologist may also recommend that you sleep
on the side opposite the operated eye and protect it during sleep by
wearing a plastic shield.
Because it is not possible to know the precise size of the
opening to make in the eye to drain fluid, sometimes too much fluid
may drain after surgery. If this happens, it usually lasts for only
a few days, but during that time the eye pressure may be too low. It
is difficult for the eye to adjust to this low eye pressure and it
can cause problems if left untreated, such as formation of a
cataract.
Another problem which can occur after trabeculectomy relates to
natural healing. The natural response of the body to an injury is
for healing to occur by formation of a scar. If the healing response
is strong, too much scar tissue will be produced. The scar tissue
can overgrow the site of the operation and seal the drainage hole.
If this occurs, the eye pressure will rise again and require a
return to eye drops, pills or possibly another operation to reduce
the pressure.
Is there success with trabeculectomy?
Although the results of the trabeculectomy depend on numerous
factors and can vary greatly, as a general rule approximately 70% of
operated eyes will have satisfactory eye pressure and no need for
medication one year after surgery. If eye drops are added, over 90%
of eyes will have a satisfactory lowering of eye pressure.
Back to
the Glaucoma Associates of Texas Surgical Procedures page
Back to top
| Home
| Glaucoma Medications | Surgery
| Studies |
|
Our
Physicians
| New Patient Information |
Locations
| Links |
| Contact
Us | Glaucoma Information | Privacy
Notice | Website
Map |
Glaucoma Associates of Texas
7150 Greenville Avenue, Suite 300
Dallas, TX 75231
Office: 214-360-0000
Fax: 214-360-0083
Copyright
© Glaucoma Associates of Texas 2000-2003
|
