Surgery Overview

Tube-shunt surgery (seton glaucoma surgery) involves placing a flexible plastic tube with an attached silicone drainage pouch in the eye to help drain fluid (aqueous humour) from the eye. This type of surgery is usually done after a trabeculectomy that failed. If a person already has or is likely to form scar tissue in the eye, this type of surgery may be done at the start.

Tube-shunt surgery can be done with the person asleep (general anesthesia) or with anesthetic applied only to the eye (local anesthesia).

What To Expect

Most people don't have to be admitted to the hospital. But children who have the surgery may stay in the hospital overnight. And in some cases, your doctor may recommend that you stay in the hospital overnight after surgery.

You will probably see the doctor within a day after tube-shunt surgery and several other times during the weeks after surgery, depending on your recovery. It is very important to keep these appointments.

After surgery, antibiotics may be applied to the eye. They may also be injected under the lining of the eyelid (conjunctiva) at the time of the surgery. At the end of surgery, the eyelid is usually taped shut, and a hard covering (eye shield) is placed over the eye. Corticosteroid medicines are usually applied to the eye for about 1 to 2 months after surgery to reduce inflammation in the eye.

Physical activity that might jar the eye needs to be avoided after surgery. For several weeks after surgery, you will probably need to avoid bending, lifting, and straining.

After surgery, people who have problems with constipation may need to take laxatives to avoid straining while trying to pass stools. Straining can raise the pressure inside the eye. Your doctor may suggest wearing a shield at night to avoid rubbing the eye when you sleep.

Why It Is Done

Tube-shunt surgery is most often used for people who have had previous trabeculectomy surgery that was not successful, usually due to scarring.

Tube-shunt surgery is also frequently used to treat glaucoma when a person has a:

• Difficult case of glaucoma and the doctor thinks that other surgical methods may fail.
• Form of glaucoma in which new blood vessels grow on the coloured part of the eye, or iris. This is called neovascular glaucoma and occurs primarily in people who have diabetes or who have vascular diseases in the eye. It is difficult to control.
• Corneal transplant, which is a surgery to replace the clear surface on the front of the eye (cornea).

How Well It Works

More than half of tube-shunt surgeries are successful. This surgery has been shown to reduce intraocular pressure (IOP) and the need for further glaucoma treatment.^{footnote 1}

Risks

Complications of tube-shunt surgery that may occur right after surgery include:

• High pressure in the eye, causing the space in the front part of the eye (anterior chamber) to collapse (malignant glaucoma).
• Inflammation in the eye.
• Bleeding or blood in the eye (hyphema).
• Softening of the eyeball due to fluid loss (hypotony).
• Movement of the tube causing it to come in contact with the clear cover of the eye (cornea), the iris, or the lens. This can affect vision or proper function of the eye.

Late complications of tube-shunt surgery include:

• Scar tissue forming around the device. The chances of this complication can be reduced if medicines, such as steroids, are used.
• Softening of the eyeball due to fluid loss (hypotony), leading to clouding of the lens (cataract).
• Infection in the eye.
• Blood in the eye (hyphema).
• Eye muscle imbalance, resulting in double vision.