Implanted aqueous shunt devices for glaucoma surgery

1. Posterior tube shunt implants address the problem of external bleb scarring by creating a large encapsulated area for filtration of aqueous humor posterior to the limbus. 2. These shunts consist of an open tube that is placed into the anterior chamber to shunt aqueous humor posteriorly into an area of encapsulation around an episcleral explant sutured to the globe 10 mm to 12 mm posterior to the limbus. 3. Posterior tube shunts are rarely used as the primary glaucoma surgical procedure: they are made of foreign materials, and surgery can be associated with a higher incidence of operative and postoperative complications.