Last updated: October 2, 2026
Glaucoma drainage implant surgery creates an alternate pathway for fluid to leave the eye. A small tube carries aqueous fluid to a plate positioned beneath the conjunctiva, where the fluid is absorbed. This category may be considered when medication, laser treatment, minimally invasive glaucoma surgery, or a prior filtering procedure has not lowered pressure enough, or when the type and severity of glaucoma make a drainage implant a reasonable option.
The goal is to reduce the risk of additional optic-nerve damage. Surgery cannot restore vision already lost to glaucoma, and it cannot guarantee that pressure medication or another procedure will never be needed.
Who May Be Evaluated
Evaluation may include the glaucoma type and stage, target pressure, visual-field and optic-nerve change, angle anatomy, prior eye surgery, cataract status, corneal health, medication tolerance, scarring, and the patient’s ability to attend close postoperative follow-up. Drainage implants are not limited to one glaucoma type, but the device and technique are selected for the individual eye.
How the Procedure Works
The surgeon places a thin tube in the front portion of the eye and positions a plate beneath the conjunctiva. Fluid moves through the tube to the plate and is absorbed by surrounding tissue. Some implants restrict flow immediately, while others are designed to begin functioning after a capsule forms around the plate. The surgeon explains the specific device, location, and postoperative plan.
Potential Benefits
- May lower eye pressure when less invasive treatment is insufficient
- Can be used in eyes with prior glaucoma or other eye surgery
- May reduce medication burden, although continued drops are sometimes needed
- Provides an alternative to trabeculectomy in selected eyes
Risks and Follow-Up
Possible risks include infection, bleeding, inflammation, pressure that is too high or too low, tube obstruction or exposure, corneal damage, double vision, cataract progression, retinal or choroidal complications, vision loss, and the need for revision or another procedure. Follow-up is essential because pressure and healing can change during the weeks and months after surgery.
Drainage Implant Compared With Other Surgery
Trabeculectomy creates a guarded opening through the eye wall, while a drainage implant uses a tube and plate. XEN creates a smaller bleb-forming pathway in selected refractory open-angle glaucoma. MIGS procedures generally use smaller incisions and may have a different risk and pressure-lowering profile, but they may not be sufficient for every advanced or difficult glaucoma case.
Compare glaucoma treatment categories.
Questions to Ask the Surgeon
- Why is a drainage implant being recommended instead of laser, MIGS, XEN, or trabeculectomy?
- Which device and location are planned?
- What is the target pressure for my eye?
- What medications will I use before and after surgery?
- How often will I need follow-up?
- Which symptoms require an urgent call?
Schedule a Glaucoma Evaluation
Call 1-800-309-2020 or request an appointment. Treatment availability and the surgeon assigned to care should be confirmed during the consultation.
Patient Education Source
This page provides general education and does not replace a glaucoma examination or individualized surgical counseling.
