Glaucoma is a progressive eye disease that damages the optic nerve due to high intraocular pressure (IOP). If left untreated, it can lead to permanent vision loss. While eye drops, laser treatments, and conventional surgeries like trabeculectomy help manage glaucoma, some cases require tube shunt surgery for better pressure control. This procedure is particularly beneficial for patients with severe or uncontrolled glaucoma.

What is Tube Shunt Surgery?

Tube shunt surgery, also known as glaucoma drainage device implantation, is a surgical procedure that lowers intraocular pressure by creating an alternative drainage pathway for excess fluid (aqueous humor) inside the eye. A small, flexible tube (shunt) is implanted Glaucoma in the eye to redirect fluid to an external reservoir, allowing it to be absorbed safely.

This surgery is commonly recommended when:

• Previous glaucoma treatments (medications, laser therapy, or trabeculectomy) have failed.
• The patient has secondary glaucoma (e.g., neovascular, uveitic, or congenital glaucoma).
• The eye is at high risk for scarring after conventional procedures.

How Does the Tube Shunt Work?

The tube portion of the device is inserted into the front chamber of the eye, while the plate (a small reservoir) is positioned beneath the conjunctiva (the white outer layer of the eye). This setup allows aqueous fluid to flow out of the eye through the tube and collect in the plate, where it is gradually absorbed into surrounding tissues. By bypassing the blocked natural drainage system, the shunt helps reduce intraocular pressure and prevent further optic nerve damage.

Types of Tube Shunts

Several types of glaucoma drainage devices are available, with the most commonly used being:

1. Ahmed Glaucoma Valve – A valve-controlled device that regulates fluid outflow to prevent sudden drops in IOP.
2. Baerveldt Glaucoma Implant – A non-valved device that requires a gradual opening period before full functionality.
3. Molteno Implant – One of the earliest tube shunts, used for complex glaucoma cases.

The choice of device depends on the patient’s condition, surgeon’s preference, and the severity of glaucoma.

Procedure: What to Expect

Before Surgery

• The patient undergoes a comprehensive eye exam to assess eye health.
• Discontinuation of certain medications, such as blood thinners, may be required.
• The procedure is typically done under local or general anesthesia.

During Surgery

• The surgeon makes a small incision to implant the tube and plate.
• The plate is placed under the conjunctiva, while the tube is inserted into the anterior chamber.
• Sutures may be used to keep the device secure.
• The surgery takes about one to two hours.

Recovery and Aftercare

• The eye may be red, swollen, or irritated for a few weeks.
• Prescription eye drops help reduce inflammation and prevent infection.
• Avoid strenuous activities, heavy lifting, and rubbing the eye.
• Vision may be blurry initially but should gradually improve.
• Regular follow-ups are necessary to monitor IOP stability and device function.

Benefits and Risks of Tube Shunt Surgery

Benefits

✔ Effective in lowering intraocular pressure.
✔ Suitable for patients who have failed other treatments.
✔ Long-term pressure control in advanced glaucoma cases.

Risks

⚠ Hypotony (pressure dropping too low).
⚠ Tube blockage or migration.
⚠ Corneal damage or double vision in rare cases.

Tube shunt surgery is a lifesaving procedure for patients with severe glaucoma that cannot be managed with conventional treatments. While it carries some risks, the benefits often outweigh them for those at risk of blindness. Regular monitoring and post-operative care are essential to ensure successful outcomes and long-term vision preservation.