by EBSCO Medical Review Board


Glaucoma surgery lowers the pressure of the fluid inside the eye. This can prevent damage to the eye and loss of vision.

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Reasons for Procedure

This procedure is done to treat glaucoma when other methods have not helped. It may prevent the disease from getting worse. It cannot undo damage that has already been done.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • Excess bleeding
  • Problems from anesthesia, such as wheezing or sore throat
  • Infection
  • Blood clots
  • Long-term irritation and inflammation of the eye
  • Loss of vision
  • Need for more surgery

Things that may raise the risk of problems are:

What to Expect

Prior to Procedure

The surgical team may meet with you to talk about:

  • Anesthesia options
  • Any allergies you may have
  • Current medicines, herbs, and supplements that you take and whether you need to stop taking them before surgery
  • Fasting before surgery, such as avoiding food or drink after midnight the night before
  • Arranging a ride to and from surgery


The doctor may give:

  • Eye drops to numb the eye
  • A sedative—you will feel relaxed
  • Local anesthesia—the area will be numbed
  • General anesthesia —you will be asleep

Description of the Procedure

The surgery you will have will depends on the type and severity of your glaucoma. There are three types of surgery:

Laser Surgery

A focused beam of light will be used to make a small opening in the eye tissue to help drain fluid.

Laser surgeries for open angle glaucoma are:

  • Argon laser trabeculoplasty (ALT) : You will sit facing the laser machine. The laser "spot" will be applied to a special contact lens held on the front of the eye. You may see flashes of red or green light as the laser is applied.
  • Selective laser trabelculoplasty (SLT) : This procedure is similar to ALT. SLT can be repeated. ALT cannot be done more than twice.
  • Laser cyclophotocoagulation : A laser is used to destroy the parts of the eye that make fluid. This is done on people with severe damage who have not been helped by other surgeries.

Laser peripheral iridotomy (LPI) : A laser is used to make a small hole in the iris. This will allow fluid to flow more freely. This is done to treat closed and narrow angle glaucoma.

Incisional Surgery (also known as Filtering Surgery)

Incisional surgery uses tiny instruments to remove a piece from the wall of the eye. This creates a small hole that will allow fluid to drain. A valve may also be put in place.

Trabeculectomy is surgery to make a small flap in the outer white coating of the eye. It is done to treat open angle glaucoma.

Peripheral iridotomy (LPI) removes a small piece of the iris. This will allow fluid to drain. This surgery is done to treat closed and narrow angle glaucoma.

Alternative Surgery

People who are not helped by other surgeries may have implants. A small tube or filament will be inserted into the front chamber of the eye. Fluid will drain through the tube or along the filament and into the area around the back end of the implant. The fluid collects here and is reabsorbed. Surgery types are:

  • Ex-Press mini glaucoma shunt
  • Trabectome
  • Canaloplasty

How Long Will It Take?

About an hour

Will It Hurt?

Pain, discomfort, and blurry vision are common in the first few days. Medicine and home care help.

Post-procedure Care

At the Care Center

Right after the procedure, the staff may:

  • Give you eye drops
  • Check your vision
  • Put a shield over the eye to protect it
At Home

It will take 3 to 6 weeks to recover. Physical activity will be limited during this time. You will need to ask for help with daily activities, such as driving.

Problems to Look Out For

Call the doctor if you are not getting better or you have problems, such as:

  • Sudden eye pain
  • Pain that you cannot control with medicine
  • Loss of vision or other eyesight changes
  • Signs of infection, such as fever and chills
  • Redness, swelling, excessive bleeding, or any discharge from the eye

If you think you have an emergency, call for medical help right away.


Glaucoma Research Foundation 

National Eye Institute 


Canadian Association of Optometrists 

Canadian Ophthalmological Society 


Angle-closure glaucoma. EBSCO DynaMed website. Available at: Accessed March 22, 2021.

Glaucoma. National Eye Institute website. Available at: Accessed March 22, 2021.

Primary open-angle glaucoma. EBSCO DynaMed website. Available at: Accessed March 22, 2021.

Prum BE Jr, Rosenberg LF, et al; American Academy of Ophthalmology. Primary Open-Angle Glaucoma Preferred Practice Pattern Guidelines. Ophthalmology. 2016 Jan;123(1):P41-P111.

Treating glaucoma. The Glaucoma Foundation website. Available at: Accessed March 22, 2021.

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