Glaucoma drainage shunts and methods of use
A method of treating glaucoma in an eye utilizing an implanted shunt having an elastomeric plate and a non-valved elastomeric drainage tube. The plate is positioned over a sclera of the eye with an outflow end of the elastomeric drainage tube open to an outer surface of the plate. An inflow end of the drainage tube tunnels through the sclera and cornea to the anterior chamber of the eye. The drainage tube collapses upon initial insertion within an incision in the sclera and cornea, or at a kink on the outside of the incision, but has sufficient resiliency to restore its patency over time. The effect is a flow restrictor that regulates outflow from the eye until a scar tissue bleb forms around the plate of the shunt.
1. A method of treating glaucoma in an eye utilizing an implanted drainage device, the method comprising the steps of:
providing a glaucoma shunt comprising a plate and an elastomeric drainage tube having an open cross-section, an outflow end of the elastomeric drainage tube connected to a part of the plate and an inflow end extending away from the plate, the drainage tube having an open lumen and a tube wall with a hoop strength;
positioning the glaucoma shunt in the eye with the plate positioned on the sclera posterior to the limbus;
forming an incision at or near the limbus; inserting the inflow end of the drainage tube through the incision and the inflow end into the anterior chamber of the eye;
bending the drainage tube to extend along the sclera close to the incision to create a kink in the drainage tube as it enters the incision, the kink restricting flow through the open lumen;
securing the drainage tube to the sclera with a kinking suture close to the incision to facilitate formation of the kink;
wherein the kinking suture creates a sharp bend angle in the tube, and the sharp bend is spaced a distance from the kinking suture;
leaving the glaucoma shunt in place for a sufficient amount of time to permit formation of a scar tissue bleb around the plate; and
causing removal of the kinking suture to permit the drainage tube to resiliently expand to permit fluid flow therethrough.
2. The method of claim 1 , wherein the drainage tube is inserted into the incision at a bend angle of between about 10 degrees and about 90 degrees.