What is trabeculectomy?

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 trabecular meshwork.

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 work.

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 children who have childhood glaucoma.

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:

• Children who have congenital glaucoma.
• People who have difficult-to-control glaucoma in which new blood vessels grow on the iris (neovascular secondary glaucoma).
• People who have diabetes.
• People who have had previous eye surgery.
• People of African descent.

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.

Surgery can be stressful. This information will help you understand what you can expect. And it will help you safely prepare for surgery.

Preparing for surgery

• Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.
• Understand exactly what surgery is planned, along with the risks, benefits, and other options.
• If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your surgery. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.
• Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your surgery. Your doctor will tell you if you should stop taking any of them before the surgery and how soon to do it.
• Make sure your doctor and the hospital have a copy of your advance directive. If you don’t have one, you may want to prepare one. It lets others know your health care wishes. It’s a good thing to have before any type of surgery or procedure.

Activity

• Rest when you feel tired. Getting enough sleep will help you recover.
• Wear your glasses during the day. Wear your eye shield or patch at night for 1 week or for as long as your doctor tells you to.
• Ask your doctor when it is okay to drive.
• You can read or watch TV.
• Do not wear contact lenses for about 8 weeks, or until your doctor says it is okay.
• Do not wear eye makeup for 2 weeks. You may also want to avoid face cream or lotion.
• You can shower or wash your hair the day after surgery. Keep water, soap, shampoo, hair spray, and shaving lotion out of your eye, especially for the first week.
• Do not rub or put pressure on your eye for at least 1 week.
• Do not get your hair colored or permed for 10 days after surgery.
• Do not bend over or do any strenuous activities, such as biking, jogging, weight lifting, or aerobic exercise, for 2 weeks or until your doctor says it is okay.
• Avoid swimming, hot tubs, gardening, and dusting for 1 to 2 weeks.
• Wear sunglasses if your eyes feel sensitive to light.

Medicines

• Your doctor will tell you if and when you can restart your medicines. The doctor will also give you instructions about taking any new medicines.
• If you stopped taking aspirin or some other blood thinner, your doctor will tell you when to start taking it again.
• Follow your doctor's instructions for when to use eye drops. Always wash your hands before you put your drops in. To put in eyedrops:
  • Tilt your head back, and pull your lower eyelid down with one finger.
  • Drop or squirt the medicine inside the lower lid.
  • Close your eye for 30 to 60 seconds to let the drops or ointment move around.
  • Do not touch the ointment or dropper tip to your eyelashes or any other surface.
• Follow your doctor's instructions for taking pain medicines.
• As your eye heals, your doctor will know if you need to keep taking glaucoma medicines. You may not need any medicines, or you may be able to take less medicine than before. If you do need medicines, follow your doctor's instructions for taking them.
• If you get constipated, your doctor may recommend laxatives. These medicines help you avoid straining while trying to pass stool. Straining can increase the pressure in your eye.