Trabeculectomy is a glaucoma surgery that creates a new drainage pathway for aqueous humour, the natural fluid produced inside the eye. 

Normally, a clear fluid called aqueous humour is continuously produced inside the eye and drains out through tiny drainage channels. If these channels do not work properly, fluid can build up and increase eye pressure. Over time, high eye pressure can damage the optic nerve and lead to permanent vision loss. During trabeculectomy surgery, the surgeon creates a new drainage pathway for this fluid. Instead of leaving the eye through the usual drainage channels, some of the fluid moves into a small space under the thin outer covering of the eye, called the conjunctiva. This creates a small raised area called a filtering bleb, where the fluid collects and is gradually absorbed.

The aim of trabeculectomy is to lower eye pressure to a safer level and help protect the remaining vision from further glaucoma damage. Trabeculectomy does not repair an already damaged optic nerve and does not restore vision that has been permanently lost to glaucoma.

Your ophthalmologist may consider trabeculectomy when:

• Eye pressure remains above the desired target despite medication
• Glaucoma is continuing to progress despite treatment
• The optic nerve shows significant or progressive damage
• A very low target eye pressure is required to protect the remaining vision
• Eye drops are not tolerated or cannot be used effectively
• Previous laser treatment has not provided sufficient pressure reduction
• The overall risk of further vision loss is considered significant

The decision is based on more than one pressure reading. For example, an eye with early glaucoma may tolerate a different pressure from an eye with advanced optic nerve damage. Your target pressure is therefore individual to your eye and your stage of disease.

How Does a Doctor Decide If Trabeculectomy Is Right for Me?

There is no single test that automatically means you need trabeculectomy.

Your ophthalmologist looks at the whole picture including your eye pressure, optic nerve, visual field, OCT findings, type of glaucoma, previous treatment and how quickly the disease is changing.

• Eye pressure: Checks whether your current treatment is controlling eye pressure.
• Optic nerve: Looks for glaucoma damage and signs of progression.
• OCT scan: Measures the optic nerve and retinal nerve fibre layer.
• Visual field test: Checks for changes in your peripheral or central vision.
• Type of glaucoma: Determines whether you have open-angle, angle-closure or another type.
• Previous treatment: Reviews your response to eye drops, laser treatment or previous surgery.
• Overall eye health: Considers previous eye surgery, inflammation, scarring and other eye conditions.

Before surgery

Your ophthalmologist will review your examination and test results and confirm the surgical plan. You will receive instructions about your regular medicines, eye drops, eating and drinking, and what you should bring or arrange for the day of surgery. The type of anaesthesia used will depend on your individual circumstances and the surgeon's recommendation.

During surgery

• A small opening is made in the sclera, the white part of the eye.
• A new drainage pathway is created to help aqueous fluid leave the eye.
• The fluid collects beneath the conjunctiva and is gradually absorbed.
• This creates a small filtering bleb that helps lower eye pressure.
• An anti-scarring medicine may be used in some patients to help prevent the new drainage pathway from closing.
• The surgical technique is tailored to the patient's glaucoma, previous treatment and overall eye health.

After surgery

Your eye will be examined before you leave the centre, and you will receive postoperative instructions and prescribed eye drops. The operation itself is only one part of the treatment.

How the eye heals afterwards is equally important.

You will therefore need scheduled follow-up appointments so your ophthalmologist can monitor eye pressure, inflammation, wound healing and the filtering bleb.

What Is a Trabeculectomy Bleb?

If you have been researching trabeculectomy, you may have come across the term “bleb.” A filtering bleb is the small area beneath the conjunctiva where aqueous fluid collects after passing through the new drainage pathway. It may appear as a small, raised area on the white part of the eye. This is an expected part of the procedure rather than a separate growth or tumour.

Your ophthalmologist will examine the bleb during follow-up to assess whether it is functioning as intended and whether the eye is healing normally. Because scar tissue can affect the drainage pathway, regular postoperative review is an important part of trabeculectomy care.

What Tests Are Done Before Glaucoma Surgery?

A detailed glaucoma evaluation helps determine whether surgery is necessary and provides a baseline against which future changes can be measured. Depending on your condition, your assessment may include:

• Tonometry: Measures intraocular pressure.
• Optic nerve examination: Looks for glaucoma-related structural damage.
• OCT scan: Provides detailed imaging of the optic nerve and retinal nerve fibre layer.
• Visual field test: Assesses functional changes in your field of vision.
• Gonioscopy: Examines the drainage angle and helps determine the type of glaucoma.
• Pachymetry: Measures corneal thickness, which can be relevant when interpreting eye-pressure measurements.
• Additional eye examination: Your ophthalmologist may also examine the cornea, lens, retina and other structures before surgery.

What Is Recovery Like After Trabeculectomy?

Trabeculectomy recovery is not simply about waiting for the eye to heal. The drainage pathway needs to be monitored while the eye responds to surgery. During the early recovery period, you may notice:

• Redness
• Watering
• Mild discomfort or irritation
• Light sensitivity
• Temporary or fluctuating blurred vision
• A foreign-body sensation

These symptoms can vary between patients.

Follow-up after Trabeculectomy

Your ophthalmologist may check intraocular pressure, filtering bleb, inflammation, wound healing, vision and signs of infection or other complications. Your postoperative eye drops may also be adjusted according to how your eye is healing.

In some cases, the surgeon may need to intervene or modify treatment during the healing period to help maintain the function of the drainage pathway.

What should I avoid after trabeculectomy?

Your surgeon will give you specific restrictions based on your recovery. You may need to temporarily avoid activities that could place pressure on the eye or increase the risk of contamination or injury. Do not rub the operated eye, and do not stop or change prescribed eye drops unless your ophthalmologist tells you to.

What Are the Risks of Trabeculectomy?

Trabeculectomy can be effective at lowering eye pressure, but it is still surgery and has potential risks. Possible complications include:

• Infection
• Bleeding
• Inflammation
• Eye pressure becoming too low
• Eye pressure remaining higher than intended
• Scarring of the filtering pathway
• Filtering bleb-related complications
• Changes in vision
• Cataract progression in some patients
• Corneal or other eye complications
• Need for additional treatment or further surgery

The risk is not the same for every patient. Previous eye surgery, the type and severity of glaucoma, medications, healing response and other eye conditions can influence the outcome. Your ophthalmologist should explain the potential benefits, limitations and risks before surgery so that you can make an informed decision.

Can Trabeculectomy Cure Glaucoma?

No. Trabeculectomy does not cure glaucoma. The optic nerve damage already caused by glaucoma cannot generally be reversed. The purpose of surgery is to lower eye pressure and reduce the risk of additional damage. This means a successful operation does not mean that glaucoma has disappeared. You will still need periodic glaucoma examinations after surgery so your ophthalmologist can monitor your eye pressure and optic nerve health.

Will I Still Need Glaucoma Eye Drops After Trabeculectomy?

You may, but not every patient needs the same medication after surgery. Some patients require fewer glaucoma drops after a successful trabeculectomy. Others may continue to need medication to maintain their target eye pressure. Your ophthalmologist will make this decision based on your postoperative eye pressure and the performance of the filtering pathway.

Do not stop glaucoma eye drops yourself, even if your vision feels stable.

The cost of trabeculectomy surgery in Dubai cannot be accurately determined without assessing the patient's eye and treatment requirements.

The overall cost may depend on:

• Preoperative glaucoma investigations
• Complexity of the procedure
• Surgeon and facility charges
• Anaesthesia
• Medicines
• Postoperative reviews
• Additional treatment, if required
• Insurance coverage

At Vasan Eye & Multispeciality DSC, the treatment plan and associated costs can be discussed after your glaucoma evaluation. Vasan Eye Dubai supports major UAE insurance providers, although coverage and approval depend on the individual insurance policy and treatment.