Methods and devices for increasing aqueous drainage of the eye
Devices and methods to remove trabecular meshwork to treat glaucoma and other conditions which may not utilize cutting elements when stripping the trabecular meshwork. The trabeculorhexis parts tissue by applying non-cutting shear and tension to the tissue to disinsert the tissue from its attachments. Reducing or eliminating the need for sharp cutting implements in the eye reduces the likelihood of incisional bleeding, iris and scleral tissue maceration and further inadvertent tissue damage of the gonio structure of the eye. In another aspect, a cutting element may be used to form a circumferential slit in a wall of Schlemm's canal in conjunction with removal of trabecular meshwork or independently.
1. A method of disrupting tissue in an eye, the method comprising:
inserting a distal portion of a device into an anterior chamber of the eye, the distal portion comprising an elongate, flexible shaft, a blunt distal guide member and a tissue disruptor coupled to the shaft proximally of the blunt distal guide member, the tissue disruptor comprising a first protrusion extending radially inwardly from the shaft and a second protrusion disposed radially outwardly from the shaft;
positioning the distal portion adjacent a trabecular meshwork of the eye;
inserting the distal guide member through the trabecular meshwork and into a portion of Schlemm's Canal; and
advancing the distal guide member along a circumferential contour of Schlemm's Canal away from the portion of Schlemm's Canal, wherein as the distal guide member advances along the circumferential contour of Schlemm's Canal, the first protrusion disrupts trabecular meshwork tissue and, at the same time, the second protrusion disrupts an outer wall of Schlemm's Canal.
2. The method of claim 1 , wherein the distal portion of the device is inserted into the anterior chamber ab interno.
3. The method of claim 1 , wherein the device further comprises an introducer tube comprising a curved or bent distal portion and a lumen, and
wherein the inserting the distal portion of the device comprises inserting the curved or bent distal portion of the introducer tube into the anterior chamber, and further wherein a portion of the shaft is within the lumen of the curved or bent portion during the inserting.
4. The method of claim 3 , wherein during the inserting into the anterior chamber, the distal guide member and the tissue disruptor remain distal of the curved or bent portion of the introducer tube.
5. The method of claim 3 , wherein the advancing the distal guide member along a circumferential contour of Schlemm's Canal comprises extending the shaft from the introducer tube to advance the distal guide member along the circumferential contour of Schlemm's Canal.
6. The method of claim 5 , wherein as the shaft extends from the introducer tube, the shaft develops a spring-load.
7. The method of claim 5 , wherein as the shaft extends from the introducer tube, the shaft applies a radially outward force against an outer wall of Schlemm's Canal.
8. The method of claim 5 , further comprising varying a stiffness of the shaft by changing a length of the shaft extending from the introducer tube.
9. The method of claim 8 , where the stiffness of the shaft varies by at least a factor of 10 as the length of the shaft extending from the introducer tube increases.
10. The method of claim 5 , further comprising moving a slide to extend the shaft from the introducer tube to advance the distal guide member along the circumferential contour of Schlemm's Canal.
11. The method of claim 10 , further comprising retracting the slide to retract the distal guide member towards the introducer tube.
12. The method of claim 1 , wherein the device further comprises a proximal portion that remains outside the eye.
13. The method of claim 12 , wherein the proximal portion comprises an actuator operatively coupled to the shaft, the method further comprising operating the actuator to advance the distal guide member along the circumferential contour of Schlemm's Canal.
14. The method of claim 13 , wherein the actuator comprises a slide, the method further comprising moving the slide to advance the distal guide member along the circumferential contour of Schlemm's Canal.
15. The method of claim 1 , wherein the shaft comprises a resiliency.
16. The method of claim 15 , wherein the shaft comprises nitinol.
17. The method of claim 15 , wherein the resiliency of the shaft causes the distal guide member to slide along an inner wall or the outer wall of Schlemm's Canal during the advancing along the circumferential contour of Schlemm's Canal.
18. The method of claim 1 , wherein the distal guide member comprises a blunt, distal portion of the shaft, and further wherein the shaft comprises a wire.
19. The method of claim 1 , further comprising disinserting the trabecular meshwork tissue from attachment to other eye tissue with the first protrusion as the distal guide member advances along the circumferential contour of Schlemm's Canal.
20. The method of claim 1 , wherein disrupting the outer wall of Schlemm's Canal comprises forming a continuous slit in the outer wall of Schlemm's Canal by cutting with a cutting edge.
21. The method of claim 1 , wherein the disrupting the outer wall of Schlemm's Canal increases an effective size of Schlemm's Canal.
22. The method of claim 1 , further comprising removing the distal portion of the device from the eye without deploying or providing any implantable structure with the device.
23. The method of claim 1 , wherein a portion of the shaft has a curved shape with a radius of curvature of 5 to 9 mm.
24. The method of claim 1 , wherein the advancing the distal guide member along the circumferential contour of Schlemm's Canal comprises advancing the distal guide member around 30 to 120 degrees of the circumferential contour of Schlemm's Canal.
25. The method of claim 1 , wherein the outer wall of Schlemm's Canal comprises sclera, and further wherein, as the distal guide member advances along the circumferential contour of Schlemm's Canal, the second protrusion of the tissue disruptor forms an elongate slit in the outer wall to thin the sclera of the outer wall.
26. The method of claim 1 , wherein, as the distal guide member advances along the circumferential contour of Schlemm's Canal, the elongate flexible shaft applies a radially outward force against the outer wall of Schlemm's Canal.
27. The method of claim 1 , wherein disrupting the trabecular meshwork tissue with the first protrusion comprises removing a portion of an inner wall of Schlemm's Canal by bluntly tearing or disinserting the trabecular meshwork tissue, without cutting.
28. The method of claim 1 , wherein disrupting the outer wall with the second protrusion comprises cutting, slitting, abrading, shaving, debriding or micro-perforating the outer wall.