Glaucoma Drainage Devices & Tube Shunts in Ahmedabad — Puja Eye Hospital

Glaucoma drainage devices — also called tube shunts or aqueous shunt implants — are surgical implants used to control eye pressure in patients with complex or refractory glaucoma that has not responded adequately to other treatments.

These devices provide a reliable, long-term method of draining aqueous fluid from the eye and are a critical option for patients who are not suitable for or have not succeeded with trabeculectomy.

What Is a Glaucoma Drainage Device?

A glaucoma drainage device consists of a small silicone tube that is inserted into the anterior chamber of the eye (the fluid-filled space in front of the lens), connected to a plate or reservoir implanted on the outer surface of the eye beneath the conjunctiva. Aqueous fluid drains from inside the eye through the tube and collects around the plate, where it is absorbed by the surrounding tissues.

This creates a continuous, controlled drainage pathway that bypasses the eye’s blocked natural drainage system and maintains a safer level of intraocular pressure.

When Is a Glaucoma Drainage Device Used?

Tube shunt surgery is typically reserved for situations where other treatments have failed or are unlikely to succeed:

Patients with refractory glaucoma — persistent high eye pressure despite maximum medical therapy and previous surgical interventions
Patients who have had a failed trabeculectomy — where the bleb has scarred and is no longer functioning
Patients with neovascular glaucoma — a severe type of glaucoma associated with diabetes, retinal vein occlusion, or other vascular diseases, where the drainage angle is blocked by new abnormal blood vessels
Patients with significant conjunctival scarring from previous surgery, trauma, or chemical injury — which makes trabeculectomy technically difficult or unlikely to succeed
Patients with uveitic glaucoma — glaucoma associated with intraocular inflammation, which is associated with a high failure rate for trabeculectomy
Patients with secondary glaucoma following penetrating keratoplasty (corneal transplant)
Paediatric glaucoma cases that have not responded to angle surgery

Types of Drainage Devices

Several glaucoma drainage device designs are available. The most commonly used worldwide are the Ahmed Glaucoma Valve and the Baerveldt Glaucoma Implant. Each has distinct design features that influence how and when they are used:

Ahmed Glaucoma Valve

The Ahmed valve contains a pressure-sensitive flow-restriction mechanism that opens and closes based on the eye pressure. This reduces the risk of dangerously low eye pressure (hypotony) in the early post-operative period, making it technically easier to manage after surgery.

Baerveldt Glaucoma Implant

The Baerveldt implant has a larger plate surface area, which typically results in a larger reservoir and greater fluid absorption over time. It does not have a flow-restriction valve, which requires careful management in the immediate post-operative period but can provide lower long-term pressures.

Dr. Sheth selects the most appropriate device based on the patient’s clinical condition, previous surgical history, and specific pressure goals.

What to Expect — Surgery and Recovery

Before Surgery

A thorough pre-operative evaluation is performed to assess the eye’s anatomy and plan the surgical approach. This includes examination of the conjunctiva, assessment of previous surgical sites, and review of the eye pressure history.

During Surgery

Tube shunt surgery is performed under local anaesthesia with sedation. The surgery typically takes 60 to 90 minutes. The plate is sutured to the outer surface of the eye, and the tube is carefully positioned within the anterior chamber through a small incision. The tube is often covered with a patch graft (a small piece of donor tissue or synthetic material) to protect it and prevent erosion through the conjunctiva.

After Surgery

The post-operative period after tube shunt surgery requires careful monitoring. Eye pressure fluctuations are common in the first few weeks as the drainage mechanism establishes itself. Pressure-lowering eye drops may be required temporarily even after surgery. Follow-up visits are frequent in the first 1 to 3 months to monitor healing and eye pressure. Most patients achieve stable, significantly reduced eye pressure within 2 to 3 months of surgery.

Puja Eye Hospital- Glaucoma Eye Hospital

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Call or WhatsApp Dr. Puja Sheth: +91 8780012121 Puja Eye Hospital, Naranpura, Ahmedabad | Mon–Sat: 9:30 AM – 4:30 PM

FAQs

Can the tube shunt be felt or seen?

The plate and tube are implanted beneath the conjunctiva and are generally not visible from the outside. In some patients, a small bulge may be felt or occasionally visible under the eyelid, but this is not typically noticeable in everyday life. The tube itself, which passes through the front of the eye, is very fine and generally not visible without magnification.

Is tube shunt surgery more risky than trabeculectomy?

Tube shunt surgery and trabeculectomy have somewhat different risk profiles. Tube shunts carry a higher risk of certain complications such as tube-cornea contact over time, but may have a more predictable and durable long-term outcome in certain high-risk eyes. The choice between the two procedures depends on the individual patient’s clinical situation, and Dr. Sheth will discuss the relative risks and benefits before recommending a procedure.

Will I still need eye drops after tube shunt surgery?

Many patients require fewer eye drops after tube shunt surgery. However, achieving a very low target pressure with a tube shunt alone is not always possible, and supplementary eye drops are often still needed — though typically fewer than before surgery.

How long does a glaucoma drainage device last?

Glaucoma drainage devices are designed to be permanent implants. Long-term studies report continued function in the majority of patients at 5 and 10 years after implantation, although some degree of pressure increase over time is common as the body’s healing response gradually encapsulates the plate.

Can a drainage device be implanted if I have had a trabeculectomy?

Yes. Tube shunt surgery is frequently performed as a secondary procedure in patients whose trabeculectomy has failed. The device is implanted in a different quadrant of the eye, away from the previous surgical site, where the conjunctiva is unscarred.