A Guide to Trabeculectomy Surgery

Medically Reviewed By Vicente Diaz, MD, MBA

Trabeculectomy is a procedure that makes a pathway for fluid to drain from the eye in the treatment of glaucoma. The surgery aims to relieve eye pressure and fluid buildup, reduce symptoms, and protect your vision. Glaucoma can develop when the eye’s drainage channel is blocked or narrow. This causes fluid buildup in the eye, increasing eye pressure and possibly damaging the optic nerve.

Doctors may recommend surgery to treat glaucoma that hasn’t responded to other approaches.

Like any surgery, trabeculectomy carries some risk. However, it can help improve glaucoma and protect against further eye damage.

Read on to learn more about trabeculectomy, including its procedure, recovery, effectiveness, and risks.

What is a trabeculectomy?

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Trabeculectomy is a surgical procedure to lower pressure in the eye due to glaucoma.

It works by making a small hole and trapdoor-like flap of tissue underneath the eye’s sclera, also known as the white of the eye. Fluid can then drain from the eye, moving around any blockages and through the trapdoor. The fluid will then collect in a bleb, which is a blister-like pouch underneath the upper eyelid.

Though trabeculectomy cannot cure glaucoma or reverse vision loss, it may reduce symptoms and prevent further damage.

Doctors may recommend trabeculectomy if other, less invasive treatment approaches haven’t helped or your glaucoma is advanced.

Learn more about glaucoma treatment options and outlook.

Trabeculectomy vs. trabeculotomy

Trabeculectomy and trabeculotomy are both surgeries that treat glaucoma. However, they use different techniques.

While trabeculectomy treats glaucoma by creating a new drainage channel, trabeculotomy removes blockages in the eye’s existing drainage structure — known as the trabecular meshwork.

Trabeculectomy preparation

Your medical team will tell you how to prepare for a trabeculectomy. Before your surgery, doctors order blood tests and an electrocardiogram to check your general health.

Other preparations your medical team may ask you to take include:

  • not eating or drinking anything other than water in the hours or day before your surgery
  • taking a list of all medications and supplements you use to your appointments
  • pausing the use of certain medications or supplements before surgery if your doctor recommends it
  • not using blood thinning medications, such as aspirin
  • arranging a ride or help from someone after the procedure because you will not be able to drive

Trabeculectomy procedure

Trabeculectomy is typically performed in an operating room and involves the following steps:

  1. An anesthesiologist will provide local or general anesthesia.
  2. The surgeon will make a flap and new drainage channel close to the trabecular meshwork by cutting and reattaching a small amount of tissue from the eye.
  3. If the iris is still blocking drainage, your medical team may decide to remove a small part of it, known as an iridectomy Trusted Source International Journal of Obesity Peer reviewed journal Go to source .
  4. Your surgeon will then make a small bleb or pocket underneath the eye’s membrane, where fluid can collect and later be absorbed into the body’s circulatory system.
  5. Your medical team will inject medications to help prevent Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source scarring and further blockages, such as mitomycin-C or 5-fluorouracil. They may do this during the surgery or a follow-up appointment.

The procedure can take about an hour, but you may spend another few hours to a day in the health center while healthcare professionals monitor your recovery.

Trabeculectomy with a shunt

Sometimes, surgeons will perform a variation of trabeculectomy by placing an Ex-PRESS shunt. This is a small metal tube placed into the eye wall, allowing fluid to drain and form a bleb.

It differs from the typical trabeculectomy. Surgeons do not have to physically create the bleb themselves.

Research suggests there are benefits and disadvantages to trabeculectomy with a shunt.

For example, research from 2019 and 2022 suggests that using an Ex-PRESS shunt may be safer than traditional trabeculectomy but is possibly less effective at treating glaucoma.

Your medical team can advise on the best approach for you.

Trabeculectomy recovery

After the procedure, doctors will place an eye patch over the operated eye.

You may experience mild effects such as discomfort or blurry vision for a few hours or days after surgery. Talk with your medical team as soon as possible if your symptoms are persistent, worsening, or severe.

Doctors may recommend allowing a few weeks for recovery. The exact time off from work will depend on your condition and job.

Typical recommendations for trabeculectomy recovery include:

  • applying eye drops recommended by your doctor
  • keeping all scheduled checkup appointments
  • not wearing contact lenses in the affected eye
  • avoiding:
    • driving
    • rubbing, bumping, or pressing your eye
    • sleeping on the same side of your body that your eye was operated on
    • getting soap, shampoo, or other products in your eye
    • wearing eye makeup
    • swimming
    • physical activity, which may include exercise, household chores, and physical labor

Your doctor will let you know when you can resume different activities.

It often takes about 2–3 months for your eye to feel fully recovered. After recovery, your doctors may recommend a vision exam to see whether you need an updated glasses prescription.

Effectiveness and outlook of trabeculectomy

Trabeculectomy can be effective for some people with glaucoma, including when other treatments haven’t helped or your glaucoma is advanced.

A 2023 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source reported that trabeculectomy lowered eye pressure and protected visual function in 89% of cases 1 year after surgery. At 3 years after surgery, success rates were 72%.

Other research indicates trabeculectomy may:

One 2016 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source indicates that trabeculectomy may even improve vision long term, although more research is needed to support this.

Still, the effectiveness and outlook of trabeculectomy can vary per person and depend on many factors, such as your health and your condition’s severity.

Risks and limitations of trabeculectomy

As with any surgery, trabeculectomy carries the risk of complications. Examples of possible complications include:

  • the surgery not improving eye pressure
  • the bleb being too large, possibly making it uncomfortable
  • eye damage
  • bleb or eye inflammation Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source , which may require steroid treatment
  • bleeding
  • infection
  • earlier development of cataracts or worsening of an already present cataract
  • scarring
  • too low eye pressure

Anti-scarring medications can increase the risk of infection, even years after the surgery. It is vital to contact an eye doctor as soon as possible for any infection symptoms, even if your surgery was years ago.

Read more about eye infections, including their symptoms and when to contact a doctor.

However, serious complications after trabeculectomy are rare. Talk with a doctor if you have concerns about side effects or risks.


Trabeculectomy is a surgical procedure that helps treat glaucoma. It works by creating a drainage channel for fluid in the eye and lowering eye pressure.

Doctors may recommend trabeculectomy if other glaucoma treatments haven’t helped. Trabeculectomy may be more invasive than other options.

Trabeculectomy can reduce eye pressure long term, protecting the eye against further damage. However, as with any surgery, it has a small risk of complications.

Talk with your doctor about trabeculectomy or if you experience new symptoms after surgery.

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Medical Reviewer: Vicente Diaz, MD, MBA
Last Review Date: 2024 Mar 25
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