Glaucoma Surgery: Implant Devices
Some of the implant devices used are the Ahmed, and Baerveldt. They are named
after their inventors.
Surgery is used in the treatment of glaucoma to lower the pressure in the eye. It is
done when you are taking the highest dose of your medicines and the pressure in
your eye is still too high. You are at risk for permanent damage to your optic nerve
The goal of surgery is to lower the pressure in the eye by making a new channel to
drain the fluid from inside the eye. The body’s own healing response is to form a
scar, which can close the new drainage channel over time. Often an implant is used
in a patient who has had prior glaucoma surgery that has failed, or in a patient who
has a form of glaucoma prone to scar.
What is an Implant Device and How Does It Work?
The implant device looks like a plastic plate attached to a tube. The tube is placed
in the front part of the eye and fluid can flow from the eye through the tube under
the plate which is placed behind the eye. The plate holds a space between the
tissues on the surface of the eye where the fluid can collect and be absorbed by the
Before surgery, you are given an IV (needle
in the vein of the arm). Drugs to help you
relax are given through the IV. Drops are
put in the eye before the surgery. The eye
and the area around it are numbed so that
you feel no pain in your eye.
The eye and skin will be cleaned with a
yellow cleaning liquid. A protective sheet
will be draped over your face. The surgeon
will make a cut in the conjunctiva (the thin
outer cover of the eye). The implant device
is placed on the sclera (white part of the eye) about halfway back on the eyeball
and is stitched down. Part of the device may pass under some of the muscles of the
eye. A small hole is made where the clear cornea (front of the eye) meets the
sclera. The tip of the implant tube is tucked into this hole and remains inside the
front part of the eye. A patch of tissue will cover the tube where it lays on the white
of the eye. In some cases, the tube’s tip may be tied off for the first few days to
weeks after it is put in. The doctor will decide when to open the tube. This depends
on how your eye heals. The hole in the conjunctiva is sewn shut. When the tube is
opened, the fluid inside the eye will flow through the tube to the space made by the
plate between the conjunctiva and sclera. The body will absorb this fluid.
Implant surgery takes about 2 hours. A patch is placed over the eye, and a metal
shield is placed over the patch. Once the IV line has been removed from your arm
and you feel well enough, you can return home.
Surgery using an implant device is most often a success. Three years later, about
60% of implants are working, though most patients need medicines as well. The
body’s scarring response can still cause problems even with an implant device. A
thick cyst can form around the plate, which can prevent drainage of the eye fluid.
Sometimes drugs can be used to prevent scar tissue from forming. The doctor will
decide if this is needed. This will depend on your age, if you have had eye surgery
before, and how severe your glaucoma is.
What Are the Risks?
ξ The most common risk is that the new drain works too little or too well. If the
drain works too little, the pressure in the eye remains too high and further
treatment is needed to lower the pressure. You and the doctors will see each
other often to adjust your medicines, push on the eye, or remove the tie that may
close the implant tube for a while after surgery. If the new drain works too well,
fluid may build up behind the retina (inner lining of the eye) and may cause a
loss of vision for a short time. You may need to have a second surgery to refill
the eye and correct the problem.
ξ With an implant device, the tube which leads from the front of the eye to the
plate and the plate itself are covered with eye tissue during the operation. Over
time, the tube or plate may wear through the tissue. If this happens, you may
need to have it repaired. This is not a common problem, but you should call
your doctor if you notice any change in the way your eye looks.
ξ The tissue around the plate may also get thick and scarred. If this happens,
the fluid cannot absorb, so the eye pressure may go up. You may need further
treatment to correct the problem.
ξ The implant device may be placed under some of the muscles in your eye. If the
tissues thicken and scar around the plate or if the device itself is too thick,
the muscles can be pushed out of place. You may notice double vision if this
occurs. You may need special glasses or a second surgery to correct your vision.
ξ The tube is carefully placed in the front of the eye during the surgery. You may
be able to see its tip if you look very closely, though it should not be noticed by
others. If the tip of the tube touches the cornea (front surface of the eye) it
may cause damage. If the tip touches the lens of the eye, it may form a
cataract. It is rare for this to happen.
ξ Your vision might not be as sharp after your surgery. This should last only a
short time. Rarely (less than 5% of cases), vision may be reduced permanently.
A very rare complication is that you could go blind as a result of surgery, or
much rarer still, to die during surgery.
Before the Surgery
You will have a physical before the day of surgery to make sure that it is safe for
you to have an operation. This exam may include blood tests, an EKG (heart
tracing), and a chest x-ray.
You should stop taking blood thinners, aspirin, ibuprofen (Motrin®, Advil®,
Nuprin®, Medipren®), naprosyn (Aleve®), anti-inflammatory arthritis medicines, or
cold pills with these drugs one week before the surgery since they can cause
bleeding. You should check with your own doctor for advice on stopping these
drugs. Acetaminophen (Tylenol®) is fine to take for headache or pain.
A nurse will call you the day before surgery to tell you what time to arrive and give
you eating and drinking instructions.
After the Surgery
Leave the patch and shield on the eye for the first day and night. You will see the
doctor the next day and on a regular basis after that time. You will be given
medicine to help the eye heal and to prevent swelling and infection. You should
stop the glaucoma medicine you were taking in the eye that had surgery. You will
be told when to restart them, if needed. Keep using the glaucoma medicines you
may have been taking in the other eye.
Glasses or the eye shield should be worn at all times for the first few weeks. The
eye shield should be worn at night to protect the eye. Do not do any physical
activity which makes you strain or hold your breath. Do not lift over 15 to 20
pounds. Do not bend over from the waist; bend at the knees to reach low objects.
You may resume sexual activities when you are comfortable. Be careful for the
first few weeks.
Call the Eye Clinic right away if you have
ξ A sudden decrease in vision
ξ Increased pain or discharge in the eye
ξ A large increase in redness or swelling
ξ Nausea or vomiting
University Station Eye Clinic, 8 a.m. to 4:30 p.m., Monday through Friday
When the clinic is closed, your call will be forwarded to the hospital paging
operator. Ask for the “Eye Resident on Call”. Give the operator your name and
phone number with area code. The doctor will call you back.
If you live out of the area, call 1-800-323-8942 and ask to be transferred to the
Please call if you have any questions or concerns.
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Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or others on your health care team when using
this information. If you have an emergency, please call 911.Copyright ©1/2016 University of Wisconsin Hospital and
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