A procedure to treat glaucoma by lowering pressure inside the eye. There are two common methods: laser and incisional.The eye is normally bathed by the aqueous humor, a clear fluid that flows in and out of the eye chamber. In glaucoma, this fluid often drains too slowly out of the eye. As the fluid builds up, pressure inside the eye increases. If this pressure is not controlled, it can cause damage to the optic nerve and other parts of the eye, and loss of vision. It is important to note that while glaucoma surgery may save your remaining vision, it does not improve or restore sight.


Eye (lens, conjunctiva, iris, sclera)


  • To lower the amount of pressure in the eye
  • To reduce and/or prevent loss of vision


Risk factors for complications include, but are not limited to:

  • Obesity
  • Smoking
  • Diabetes
  • High blood pressure
  • Heart disease
  • Lung disease
  • Recent or chronic illness
  • Bleeding disorder
  • Infection


Prior to Procedure:

  • Continue to take your eye drops, unless directed otherwise by your doctor
  • If you are having the incisional technique, do not take aspirin, aspirin-containing products, anti-inflammatory drugs (e.g., ibuprofen), or certain herbal products 10 days before the procedure, or as directed by your doctor
  • Arrange for a ride to and from the procedure

During Procedure – Anesthesia; a small device placed in the eyes that holds the eyelids open.

Anesthesia - Drops to numb the eye, local, and/or IV sedation. General anesthesia is used under some circumstances.

Description of the Procedure - There are two common types of glaucoma surgery: laser and incisional. Both are usually performed as outpatient procedures.

Laser surgery - There are three main kinds of laser surgery.

Argon laser trabeculoplasty (ALT) is the most common type of laser surgery and is usually used to treat open angle glaucoma. During this procedure, you sit facing the laser machine. The laser "spot" is applied to a special contact lens held on the front of the eye and reflected onto the drainage meshwork inside the eye. You may see flashes of red or green light as the laser is applied. This procedure allows more fluid to be released and relieves some of the pressure.

Selective laser trabeculoplasty (SLT) is a relatively new treatment that is similar in mechanism to ALT.

Laser peripheral iridotomy (LPI) is frequently used to treat narrow-angle glaucoma. Narrow-angle glaucoma occurs when the angle between the cornea and the iris (the colored part of the eye) is too small. This can cause the iris to "plug up" the drainage meshwork inside the eye, so fluid cannot flow freely. This can cause the pressure to raise to dangerously high levels very quickly. In LPI, the surgeon uses the laser to make a small hole in the iris, which allows fluid to flow more freely within the eye.

Cyclophotocoagulation freezes selected parts of the eye that produce the aqueous humor, thereby reducing the production of fluid. This procedure is done only in people who have severe damage from glaucoma and for whom other surgeries were not successful. Instead of freezing, this procedure can also be performed with a laser.

Incisional surgery - Also known as filtering surgery, incisional surgery requires the use of tiny instruments to remove a tiny piece from the wall of the eye, leaving a microscopic hole. The aqueous humor can now drain out through the hole and be reabsorbed into the bloodstream. This reduces the pressure in the eye. In some cases, the surgeon may place a valve in the eye through a tiny incision. Some types of these valves act as regulators for the buildup of fluid within the eye. When the pressure becomes too high, the valve opens and allows the fluid to flow out and be reabsorbed.

After Procedure - Eye and pressure exam, eye drops, eye patch

How Long Will It Take? Usually less than 1 hour, although people having the incisional procedure are often told to allow about 4 to 8 hours from the time of arrival until discharge.

Will It Hurt? Most patients report no pain throughout either procedure, although there may be some burning or stinging with ALT and LPI. Some patients report mild discomfort during the procedures.

Possible Complications:

  • Sensitivity to light
  • Scratchiness
  • Undesirable changes in intraocular pressure
  • Red, inflamed eyes
  • Infection
  • Inflammation
  • Bleeding
  • Loss of vision
  • Loss of eye
  • Need for more surgery

Average Hospital Stay - None

Postoperative Care:

  • If given an eye patch or bandage, wear it as directed by your doctor
  • Use eyedrops as prescribed; these drops will help prevent infection and inflammation
  • Avoid activities that expose your eye to water like swimming or showering
  • Refrain from heavy lifting, straining, or driving for several days
  • Follow your surgeon's advice regarding resumption of exercise and other activities


Laser trabeculoplasty often relieves intraocular pressure, but the effects can wear off over time. In most cases, medications are still necessary to control and maintain eye pressure, but surgery may lessen the amount of medication needed.


  • Signs of infection, including fever and chills
  • Sudden change in vision
  • Pain in your eye
  • Bleeding
  • Redness, swelling, increasing pain, excessive bleeding, or discharge in the surgical area
  • Cough, shortness of breath, chest pain, or severe nausea or vomiting

National Eye Institute

American Academy of Ophthalmology

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