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Glaucoma Filtration Surgery

Also known as: Trabeculectomy

What it is:

Glaucoma Filtration Surgery is the most common surgery for open-angle glaucoma. It helps the eye drain liquid more effectively.

What You Can Expect:

This is an outpatient surgery usually performed in less than an hour. You will be able to go home the same day.

Who Is a Good Candidate:

If your glaucoma medications cannot lower eye pressure enough, your ophthalmologist (Eye M.D.) will probably recommend surgery.

In-Depth Information:

What It’s For How It Works Risks All

What It’s For

A clear liquid called aqueous humor circulates inside the front portion of the eye. In open-angle glaucoma, this liquid does not flow efficiently through the eye’s sponge-like drainage system (known as the trabecular meshwork). When this liquid fails to drain properly, pressure builds within the eye.

The medical term for this pressure is intraocular pressure. Such pressure inside the eye may damage the optic nerve and lead to vision loss. Glaucoma filtration surgery is one procedure that may help lower intraocular pressure.

How It Works

Glaucoma filtration surgery is also known as trabeculectomy. It is done as an outpatient surgery with a local anesthetic. You may be given a sedative to help you relax. The procedure is usually performed in less than an hour.

Your Eye M.D. will make a small flap in the white of the eye (the sclera). This is followed by the creation of a reservoir called a filtration bleb. The aqueous humor can drain into this reservoir and be absorbed into the blood vessels around the eye.

After carefully constructing the filtration bleb, your doctor will close the incision in the sclera with tiny stitches. Some of these stitches may be released after surgery to increase fluid drainage.

Drugs to reduce scarring are often applied during and after surgery.

Although the success rate is quite high, sometimes a single surgical procedure cannot halt the progression of glaucoma. Another surgery and/or continued treatment with medications may be necessary.


As with all surgeries, there are risks associated with glaucoma filtration surgery. One of the most common complications is scarring.

An eye that has undergone glaucoma filtration surgery and has a functioning bleb will always be at risk for infection. A red, uncomfortable eye may be a sign of infection and requires urgent medical attention.

Other complications include bleeding, cataract, or loss of vision.

Pain is unusual after surgery, although your eye may feel tender and sensitive. A non-aspirin pain reliever is usually enough to treat any discomfort. Sudden, severe, or deep-seated pain, especially if it is associated with loss of vision, should be reported to your Eye M.D. immediately.

Postoperative care is as important to the long-term success of the operation as the surgery itself. In follow-up appointments, your Eye M.D. will examine the filtering bleb, the external appearance of the eye, your eye pressure, and the back of your eye. You should avoid lifting, bending, or straining after surgery until your eye pressure stabilizes.

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