Glaucoma is a serious eye disease that damages the optic nerve and causes progressive vision loss. If treated, glaucoma-related blindness can be prevented. Glaucoma is characterized by increased intraocular pressure (IOP) in the aqueous humor in front of the iris. Aqueous humor exits the iris to the cornea through tiny channels called trabeculum, but sometimes those channels are blocked. As a result, pressure from the aqueous humor builds. Sometimes there are symptoms of the pressure such as pain and redness, but often there are no symptoms at all until eyesight has been damaged.

Trabeculectomy is a surgical procedure to remove part of the trabeculum in the eye to reduce pressure caused by glaucoma. Trabeculectomy is used to treat open-angle glaucoma and chronic closed-angle glaucoma. If your medicated eye drops are not effective in reducing pressure in your eyes, you could be at risk for permanent sight damage. Trabeculectomy could be essential in halting the progression of your glaucoma.

During Your Surgery

Several eye drops will be administered before surgery begins. Your eye will be sterilized and you will receive local or even topical anesthetic.

The goal of trebeculectomy is to create a filtration system for the buildup of aqueous humor so the intraocular pressure is diminished. This is done by removing a piece of your eye tissue from the drainage angle of the eye to create an opening. The outer white coating of your eye called the sclera is cut open to make a flap for the aqueous humor to drain. A filtration reservoir called a bleb is created under the thin membrane called the conjunctiva that covers the white part of your eye. Similar in appearance to a blister, the bleb looks like a bump on the white part of the eye above the iris. The trapped aqueous humor can now circulate and drain through the flap and collect in the bleb. The fluid will be absorbed into the surrounding blood vessels and intraocular pressure will decrease. Your surgeon will then close the scleral flap and conjuncitiva with sutures.

After the Surgery

You may experience discomfort after surgery, but this is normal. You will probably be given antibiotics directly after the procedure, and you may receive an injection of antibiotics under the lining of the conjunctiva. Your eye will be covered with an eye dressing during the first night after surgery, but after that your eye will be taped shut and you will wear a hard covering called an eye shield at bedtime. If you had the procedure done at an outpatient surgery center, you will have an appointment with your eye specialist the day following the procedure.

You may experience a few temporary side effects such as blurred vision, eye pain and sensitivity to light. Your doctor will prescribe antibiotics and corticosteroids (anti-inflammatory eye drops) that you will use for at least six weeks after the procedure. You may also need to take additional medication to reduce scarring.


Trabeculectomy has proven to reduce intraocular pressure in three out of four patients, but many people need more trabeculectomy surgery as well as other glaucoma treatments. Other people have such positive results that they no longer need glaucoma drops, but they still should make regular visits to their eye specialist. This procedure is not considered a cure, and people can still experience vision loss even after surgery. Trabeculectomy seems to be less successful if you are:

  • Diabetic
  • African American
  • A child who has congenital glaucoma
  • Someone who has had previous eye surgeries
  • Someone who has neovascular secondary glaucoma or difficult-to-control glaucoma