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Home > Patients & Visitors > Health Library > Trabeculectomy (Filtration Surgery) for Glaucoma
During trabeculectomy—sometimes also called
filtration surgery—a piece of tissue in the
drainage angle of the eye is removed, creating an
opening. The opening is partially covered with a flap of tissue from the
sclera, the white part of the eye, and the conjunctiva, the clear thin covering
over the sclera. This new opening allows fluid (aqueous humor) to
drain out of the eye, bypassing the clogged drainage channels of the
As the fluid flows
through the new drainage opening, the tissue over the opening rises to form a
little blister or bubble, called a bleb. The bleb is located where the sclera,
or white of the eye, joins the iris, the colored part of the eye. During office
visits after surgery, the doctor looks at the bleb to make sure that fluid is
still draining out of the new opening. Not all blebs have to be easily seen to
The person does not have to be
admitted to the hospital. But children may stay in the hospital overnight
following surgery. And in some cases, your doctor may recommend that you stay
in the hospital.
Right after surgery, antibiotics may be
applied to the eye. Also, antibiotics may be injected under the lining of the
eyelid (conjunctiva). After surgery, the eyelid is usually taped shut, and a
hard covering (eye shield) is placed over the eye. The person
wears a dressing over the eye during the first night after surgery and wears
the eye shield at bedtime for up to a month. Corticosteroid medicines are usually
applied to the eye for about 1 to 2 months after surgery to decrease
inflammation in the eye.
A person who has a trabeculectomy usually has a checkup the following day with
his or her eye specialist.
Any activity that might jar the eye needs to
be avoided after surgery. People usually need to avoid bending, lifting, or
straining for several weeks after surgery.
After surgery, people
who have problems with constipation may need to take laxatives to avoid
straining while trying to pass stools. Straining can raise the pressure inside
the eye (intraocular pressure), increasing the risk of bleeding or damage to the optic nerve.
Usually there is mild discomfort after a trabeculectomy. Severe pain may
be a sign of complications. If you have severe pain after a trabeculectomy,
call your doctor immediately.
Trabeculectomy is used to treat open-angle glaucoma and chronic closed-angle glaucoma. Trabeculectomy is usually done
when medicine or laser treatment or both have failed to reduce the pressure in the
eyes enough to prevent damage to a person's eyesight.
Trabeculectomy is not the first surgery used for treating babies who have
The new opening created by
trabeculectomy allows fluid to gather under the tissue that lines the eyeball
(conjunctiva), where it is absorbed into the bloodstream.
This procedure lowers pressure inside the eye. But some people need
another trabeculectomy surgery or other treatments for glaucoma. Trabeculectomy
is less likely to be successful in:
The long-term effectiveness of trabeculectomy surgery in
preventing loss of vision from glaucoma is less certain. It is not a cure. And
visual field loss can continue despite surgery.
The most common problem after a trabeculectomy
is scarring of the opening. Scarring prevents fluid drainage from the eye and
interferes with the proper function of the bleb. If
the bleb doesn't work or causes problems, more surgery may be needed.
The medicine mitomycin is commonly used
during surgery to prevent scarring. It is more commonly used than
5-fluorouracil, but it cannot be used after surgery. 5-fluorouracil can be used
during the surgery or injected into the thin tissue (conjunctiva) covering the
eye after surgery to prevent scarring.
Other complications of this
surgery that may develop soon after surgery include:
Late complications after a trabeculectomy may
Trabeculectomy is the most commonly done glaucoma surgery that doesn't use a laser. If you are having this type of
surgery, talk with your doctor about its possible risks and benefits for
Trabeculectomy may be combined with surgery to remove a
Stitches placed during surgery
may be cut after surgery if fluid is not draining well from the eye. Your doctor may ask you to massage the bleb to help the fluid drain.
Complete the surgery information form (PDF)(What is a PDF document?) to help you prepare for this surgery.
ByHealthwise StaffPrimary Medical ReviewerAdam Husney, MD - Family MedicineSpecialist Medical ReviewerChristopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology
Current as ofMay 23, 2016
Current as of:
May 23, 2016
Adam Husney, MD - Family Medicine & Christopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology
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