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.
Glaucoma drainage device surgery, also called tube shunt surgery, implants a small medical device to create a new pathway for fluid to drain out of the eye and lower eye pressure. The device consists of a thin silicone tube inserted into the front chamber of the eye, connected to a small plate that is stitched onto the sclera further back, usually hidden under the upper eyelid, where fluid collects and is absorbed by surrounding tissue. It is often used when a previous glaucoma surgery, such as trabeculectomy, has not adequately controlled eye pressure, or in eyes where scarring makes trabeculectomy less likely to succeed. Several device designs exist, and the surgeon selects the one best suited to the individual eye.
Who typically needs this
- Often recommended after a previous trabeculectomy or other glaucoma surgery has failed to control eye pressure.
- Considered for eyes with scarring of the conjunctiva from prior surgery, trauma, or certain eye diseases that make trabeculectomy less likely to succeed.
- Used for certain complex or high-risk forms of glaucoma, including neovascular glaucoma and glaucoma following corneal transplant.
- May be chosen as an initial surgery in specific cases where the ophthalmologist judges it more likely to succeed than trabeculectomy.
What to expect
- Performed under local anesthesia with sedation or general anesthesia, typically as day surgery.
- The surgeon positions the drainage plate on the sclera beneath the conjunctiva, usually toward the back of the eye under the upper eyelid.
- A thin silicone tube from the plate is threaded into the front chamber of the eye to carry fluid to the plate, where it collects and is absorbed by surrounding tissue.
- Some devices include a valve that regulates flow immediately; others are non-valved and may be temporarily tied off, opening fully several weeks later.
- The procedure generally takes about an hour.
Recovery
- Vision is often blurry for the first days to weeks after surgery, and the eye may be red or mildly uncomfortable.
- Regular follow-up visits are needed in the following weeks to check eye pressure and healing, especially as a tied-off tube is allowed to open.
- Antibiotic and anti-inflammatory drops are used for several weeks; other glaucoma medications may still be needed while pressure stabilizes.
- Strenuous activity, swimming, and eye rubbing should be avoided for several weeks, as advised by the surgeon.
Risks to know about
- Double vision can occur if the implant affects the muscles that move the eye.
- The tube or plate can occasionally erode through the overlying tissue, become blocked, or shift out of position, sometimes requiring further surgery.
- Eye pressure can temporarily spike in the weeks after a non-valved tube is opened, or drop too low (hypotony) in some cases.
- Less common risks include bleeding, infection, and inflammation inside the eye.
Frequently asked questions
How is this different from trabeculectomy?
Trabeculectomy creates a drainage flap using the eye's own tissue, while a tube shunt uses an implanted device to route fluid to a drainage plate. The surgeon recommends whichever is more likely to work well for a particular eye.
Can I feel the device in my eye?
Most patients do not feel the implant once healing is complete, since it sits beneath the eyelid and conjunctiva, though some notice a firmness under the upper lid.
Is this surgery permanent?
The device usually remains in the eye long-term and is not designed to be routinely removed, but further surgery can be done if problems develop.
Will I still need glaucoma drops?
Many patients need fewer drops afterward, but some continue to need medication to reach their target eye pressure.
Ready to see us?
Call the appointment desk, or book online — we will confirm your time by phone.
Sources consulted: AAO — Consider Tube Shunts for Glaucoma Surgery, 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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