Last updated: 02/17/2009

Tube-shunt surgery, or Seton tube shunt glaucoma surgery, is a surgical method to treat glaucoma. Glaucoma is a potentially blinding disease affecting 2–3% of the United States population. The major known cause of glaucoma is a relative increase...

in intraocular pressure, or IOP. The purpose of glaucoma treatment, whether medical or surgical, is to lower the IOP.

Aqueous fluid is made continuously, and circulates throughout the eye before draining though channels in the eye's anterior chamber. When too much fluid is made, or it is not drained sufficiently, the IOP rises. This fluid build-up can lead to glaucoma. Normal intraocular pressure is under 21 mm/Hg. Glaucoma develops at IOPs higher than 21mm/Hg. However, approximately 20% of glaucoma patients never have pressures higher than 21 mm/Hg.

Seton tube implants are also called glaucoma drainage tubes or implants. The Seton implant is comprised of two parts:

• Tubing, a portion of which is implanted along the inside of the front of the eye. The distal (furthest from the center) end of the tubing protrudes through the anterior (front) or less commonly, the posterior (rear), chamber of the eye.
• An attached reservoir, called a plate, is placed under the conjunctiva of the eye at its equator, or midpoint.