Medically reviewed by Dr. Niranjana Bejan Singh. Written to established clinical-education standards (AAO/Mayo/NHS/NEI) and adapted for this hospital. Not a substitute for professional medical advice.
Trabeculectomy is a surgical procedure that lowers eye pressure in glaucoma by creating a new drainage channel for the fluid (aqueous humor) inside the eye. The surgeon creates a small flap in the sclera, the white outer wall of the eye, and forms a tiny reservoir called a bleb beneath the surface of the eye, usually hidden under the upper eyelid, where fluid collects and is gradually absorbed by surrounding tissue. It has been used for decades and remains one of the most established operations for lowering eye pressure when drops and laser treatment are not enough. It is typically considered when other, less invasive treatments have not kept eye pressure low enough to protect the optic nerve.
Who typically needs this
- Recommended when eye drops, oral medication, and laser treatment have not brought eye pressure down to a safe level.
- Considered for patients whose glaucoma is progressing despite maximum tolerated medical therapy.
- May be recommended earlier for some patients with very high pressure or advanced optic nerve damage at diagnosis.
- Suitable for many types of open-angle glaucoma, and some angle-closure cases once the angle has been addressed.
- The ophthalmologist weighs target eye pressure, extent of visual field damage, and overall eye health before recommending it.
What to expect
- Performed under local anesthesia (with sedation) or general anesthesia, usually as day surgery.
- The surgeon creates a small flap in the sclera and removes a tiny piece of tissue to form a new drainage opening.
- A thin covering of conjunctiva, the clear membrane over the white of the eye, is stitched over the flap, forming a bleb where fluid collects.
- Anti-scarring medication, such as mitomycin-C, is often applied during surgery to help keep the new drainage channel open longer.
- The procedure generally takes 30 to 60 minutes, and most patients go home the same day.
Recovery
- Vision is typically blurry for the first few days to weeks while the eye heals.
- Several follow-up visits in the first few weeks are needed so the surgeon can adjust stitches, manage bleb function, and check eye pressure.
- Antibiotic and anti-inflammatory eye drops are used for several weeks; additional glaucoma drops may still be needed if pressure is not yet at target.
- Strenuous activity, swimming, heavy lifting, and eye rubbing should be avoided for several weeks, as advised by the surgeon.
Risks to know about
- Bleb-related problems, including infection (blebitis) or fluid leakage, can occur and sometimes require treatment even years after surgery.
- Eye pressure can end up too low (hypotony), or the new drainage opening can scar shut over time, reducing effectiveness and sometimes requiring repeat surgery.
- Cataract formation may be accelerated after trabeculectomy.
- Less common risks include bleeding inside the eye, inflammation, and, rarely, vision loss.
Frequently asked questions
Will trabeculectomy cure my glaucoma?
No, glaucoma has no cure. Trabeculectomy lowers eye pressure to slow or stop further optic nerve damage; it does not reverse vision already lost.
Will I still need eye drops afterward?
Many patients need fewer or no glaucoma drops after a successful trabeculectomy, but some still require medication to reach their target pressure.
What is a "bleb" and will people notice it?
The bleb is a small fluid-filled blister under the upper eyelid where drained fluid collects. It is usually not visible unless someone looks closely, since the eyelid covers it.
How long does the effect of surgery last?
Many trabeculectomies continue working well for years, but the drainage opening can gradually scar over time, and additional treatment or repeat surgery is sometimes needed.
Ready to see us?
Call the appointment desk, or book online — we will confirm your time by phone.
Sources consulted: AAO — Trabeculectomy, Mayo Clinic — Glaucoma (Diagnosis & Treatment) . General medical information — not a substitute for professional diagnosis. Medically reviewed by Dr. Niranjana Bejan Singh.
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