Methods and devices for increasing aqueous drainage of the eye
View Patent ↗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, said method comprising:
inserting a distal portion of a device into an anterior chamber of the eye, said distal portion comprising an elongate, flexible shaft, a distal guide member and a tissue disruptor coupled to said shaft proximally of said distal guide member, said tissue disruptor comprising a protrusion extending radially inwardly from the shaft and a cutting edge disposed radially outwardly from the shaft said protrusion comprising a blunt tissue-engaging surface without any cutting element;
positioning said distal portion adjacent a trabecular meshwork of the eye;
inserting the distal guide member through said trabecular meshwork and into a portion of Schlemm's Canal; and
advancing the distal guide member along Schlemm's Canal away from said portion of Schlemm's Canal, wherein as the distal guide member advances along Schlemm's Canal, said tissue-engaging surface of said protrusion bluntly tears trabecular meshwork tissue to remove a portion of an inner wall of Schlemm's Canal and, at the same time, said cutting edge cuts an outer wall of Schlemm's Canal.
2. The method of claim 1 , wherein said device further comprises an introducer tube comprising a curved or bent distal portion and a lumen, and
wherein said inserting said distal portion of said device comprises inserting said curved or bent distal portion of said introducer tube into said anterior chamber, and further wherein a portion of said shaft is within said lumen of said curved or bent portion during said inserting.
3. The method of claim 2 , wherein said advancing said distal guide member along Schlemm's Canal comprises extending said shaft from said introducer tube to advance said distal guide member along Schlemm's Canal.
4. The method of claim 3 , further comprising varying a stiffness of the shaft by changing a length of the shaft extending from the introducer tube.
5. The method of claim 4 , where said stiffness of the shaft varies by at least a factor of 10 as the length of the shaft extending from the introducer tube increases.
6. The method of claim 3 , further comprising moving a slide to extend said shaft from said introducer tube to advance said distal guide member along Schlemm's Canal.
7. The method of claim 6 , further comprising retracting the slide to retract the distal guide member towards said introducer tube.
8. The method of claim 3 , wherein as said shaft extends from said introducer tube, said shaft develops a spring-load.
9. The method of claim 3 , wherein as said shaft extends from said introducer tube, said shaft applies a radially outward force against an outer wall of Schlemm's Canal.
10. The method of claim 2 , wherein during said inserting into said anterior chamber, said guide member and said tissue disruptor remain distal of said curved or bent portion of said introducer tube.
11. The method of claim 1 , wherein said device further comprises a proximal portion that remains outside the eye.
12. The method of claim 11 , wherein said proximal portion comprises an actuator operatively coupled to said shaft, said method further comprising operating said actuator to advance said distal guide member along Schlemm's Canal.
13. The method of claim 12 , wherein said actuator comprises a slide, said method further comprising moving the slide to advance said distal guide member along Schlemm's Canal.
14. The method of claim 1 , wherein said shaft comprises a resiliency.
15. The method of claim 14 , wherein said shaft comprises nitinol.
16. The method of claim 14 , wherein said resiliency of said shaft causes said distal guide member to slide along said inner wall or an outer wall of Schlemm's Canal during said advancing along Schlemm's Canal.
17. The method of claim 1 , wherein said distal portion of said device is inserted into said anterior chamber ab interno.
18. The method of claim 1 , wherein said distal guide member comprises a blunt, distal portion of said shaft, and further wherein said shaft comprises a wire.
19. The method of claim 1 , further comprising disinserting said trabecular meshwork tissue from attachment to other eye tissue with said blunt tissue-engaging surface of said tissue disruptor as said distal guide member advances along Schlemm's Canal.
20. The method of claim 1 , wherein said cutting said outer wall of Schlemm's Canal forms a continuous slit in the outer wall of Schlemm's Canal.
21. The method of claim 1 , wherein said cutting said outer wall of Schlemm's Canal increases an effective size of Schlemm's Canal.
22. The method of claim 1 , further comprising removing said distal portion of said device from the eye without deploying or providing any implantable structure with the device.
23. The method of claim 1 , wherein a portion of said shaft has a curved shape with a radius of curvature of 5 to 9 mm.
24. The method of claim 1 , wherein said advancing the distal guide member along Schlemm's Canal comprises advancing the distal guide member around 30 to 120 degrees of a circumference of Schlemm's Canal.
25. The method of claim 1 , wherein said outer wall of Schlemm's Canal comprises sclera, and further wherein, as said distal guide member advances along Schlemm's Canal, said cutting edge of said tissue disruptor forms an elongate slit in said outer wall to thin said sclera.
26. The method of claim 1 , wherein said advancing along Schlemm's Canal comprises following a circumferential contour of Schlemm's Canal.
27. The method of claim 1 , wherein, as said distal guide member advances along Schlemm's Canal, said elongate flexible shaft applies a radially outward force against said outer wall of Schlemm's Canal.
28. A method of performing a procedure on a patient's eye, said method comprising:
advancing along Schlemm's Canal a portion of a medical instrument inserted at least in part into Schlemm's Canal, and
during said advancing along Schlemm's Canal, both:
bluntly tearing or disinserting, without cutting, trabecular meshwork tissue; and, at the same time,
cutting, slitting, abrading, shaving, debriding or micro-perforating an outer wall of Schlemm's Canal.
29. The method of claim 28 , wherein said procedure is performed without deploying or providing any implantable structure.
30. The method of claim 28 , wherein said portion of said medical instrument comprises a guide member inserted into Schlemm's Canal.