Devices and methods for intraocular tissue manipulation
Provided herein are methods and devices for grasping and/or tearing trabecular meshwork of an eye of a subject. The devices may include a shaft and a tissue grabber coupled to the shaft. The tissue grabber may include an elongate lower foot configured to be inserted into Schlemm's canal, and a groove configured to grasp a portion of the trabecular meshwork. The methods may include: advancing a tissue grabber to Schlemm's canal of the eye, wherein the tissue gripper comprises a lower foot and a tissue grabbing region; advancing a tip of the lower foot through the trabecular meshwork and into Schlemm's canal; and advancing the lower foot within and relative to Schlemm's canal, wherein as the lower foot is advanced, a portion of the trabecular enters the tissue gripping region, is torn from surrounding tissue, and is collected within the tissue gripping region.
1 . A method of tearing trabecular meshwork of an eye of a subject, the method comprising:
advancing a tissue grabber at a distal end of a shaft to Schlemm's canal of the eye, wherein the tissue grabber comprises a lower foot and a groove;
advancing a tip of the lower foot through the trabecular meshwork and into Schlemm's canal;
advancing the lower foot within and relative to Schlemm's canal, wherein as the lower foot is advanced, a first central portion of the trabecular meshwork becomes trapped in the groove and a second, lateral portion of the trabecular meshwork is detached from surrounding tissue; and
withdrawing the tip through the trabecular meshwork and out of Schlemm's canal, thereby severing a third leading portion of the trabecular meshwork, the third leading portion at a leading edge of the tip as the lower foot is advanced, wherein the withdrawing of the tip occurs after the advancing of the lower foot within and relative to Schlemm's canal is stopped, wherein the withdrawing of the tip thereby withdraws a detached portion of the trabecular meshwork along with the tissue grabber, wherein the detached portion is trapped in the groove.
2 . The method of claim 1 , wherein a portion of the trabecular meshwork is detached from Schwalbe's line and the scleral spur.
3 . The method of claim 1 , wherein as the lower foot is advanced further within Schlemm's canal, the detached portion of the trabecular meshwork forms a ribbon trailing the first central portion of the trabecular meshwork trapped in the groove.
4 . The method of claim 3 , further comprising rotating the tip along a longitudinal axis of the shaft before withdrawing the tip from the eye, thereby wrapping the detached portion of the trabecular meshwork around the shaft.
5 . The method of claim 1 , wherein the lower foot is advanced within and relative to Schlemm's canal for between about 30 degrees and about 120 degrees around a circumference of the canal in a first direction.
6 . The method of claim 5 , further comprising removing the lower foot from the canal, rotating the tissue grabber along a longitudinal axis of the shaft about 180 degrees so that the lower foot is pointed in an opposite direction, re-entering the canal, and advancing the lower foot within and relative to Schlemm's canal in a second, opposite direction.
7 . The method of claim 6 , wherein the lower foot is advanced within and relative to Schlemm's canal for between about 30 degrees and about 120 degrees around the circumference of the canal in the second direction.
8 . The method of claim 1 , wherein the subject is suffering from high intraocular pressure.
9 . The method of claim 8 , wherein the high intraocular pressure is caused by glaucoma.
10 . The method of claim 1 performed as a standalone procedure.
11 . The method of claim 1 , wherein the method is performed in conjunction with cataract removal, canaloplasty, or another glaucoma treatment procedure.
12 . The method of claim 11 , wherein the glaucoma treatment procedure is selected from the group consisting of: deployment of a trabecular microbypass stent or scaffold, deployment of a suprachoroidal shunt, placement of a sustained release glaucoma pharmaceutical implant, and endoscopic cyclophotocoagulation.
13 . The method of claim 1 , wherein the tissue grabber is bladeless.
14 . The method of claim 1 , wherein the tissue grabber is coupled to the distal end of the shaft.
15 . The method of claim 14 , wherein the lower foot comprises a central longitudinal axis that is transverse to a longitudinal axis of the shaft.
16 . The method of claim 1 , wherein the groove has a variable height.
17 . The method of claim 1 , wherein the groove comprises a closed back, and the closed back is rounded.
18 . The method of claim 17 wherein a radius of curvature of the closed back of the groove is at least 10 microns, at least 15 microns, at least 20 microns, about 10 microns, about 15 microns, or about 20 microns.
19 . The method of claim 1 , wherein the tissue grabber comprises an upper foot and the groove is formed between the lower foot and the upper foot.
20 . The method of claim 19 , wherein a length of the lower foot is greater than a length of the upper foot.
21 . The method of claim 19 , wherein a maximum width of the upper foot is greater than a maximum width of the lower foot.
22 . The method of claim 1 , wherein the lower foot comprises a roughened surface at a distal end of the lower foot, wherein the roughened surface is configured to grab the trabecular meshwork, thereby promoting the trabecular meshwork becoming trapped in the groove.
23 . A method of tearing trabecular meshwork of an eye of a subject, the method comprising:
advancing a tissue grabber at a distal end of a shaft to Schlemm's canal of the eye, wherein the tissue grabber comprises a lower foot and a groove;
advancing a tip of the lower foot through the trabecular meshwork and into Schlemm's canal;
advancing the lower foot within and relative to Schlemm's canal, wherein as the lower foot is advanced, a first central portion of the trabecular meshwork becomes trapped in the groove and a second, lateral portion of the trabecular meshwork is detached from surrounding tissue, wherein as the lower foot is advanced further within Schlemm's canal, a detached portion of the trabecular meshwork forms a ribbon trailing the first central portion of the trabecular meshwork trapped in the groove; and
rotating the tip along a longitudinal axis of the shaft before withdrawing the tip from the eye, thereby wrapping the detached portion of the trabecular meshwork around the shaft.
24 . The method of claim 23 , further comprising withdrawing the tip from the eye, thereby withdrawing the detached portion of the trabecular meshwork along with the tissue grabber.
25 . The method of claim 23 , wherein the lower foot is advanced within and relative to Schlemm's canal for between about 30 degrees and about 120 degrees around a circumference of the canal in a first direction.
26 . The method of claim 25 , further comprising removing the lower foot from the canal, rotating the tissue grabber along the longitudinal axis of the shaft about 180 degrees so that the lower foot is pointed in an opposite direction, re-entering the canal, and advancing the lower foot within and relative to Schlemm's canal in a second, opposite direction.
27 . The method of claim 26 , wherein the lower foot is advanced within and relative to Schlemm's canal for between about 30 degrees and about 120 degrees around the circumference of the canal in the second direction.
28 . The method of claim 23 , wherein the subject is suffering from high intraocular pressure.
29 . The method of claim 28 , wherein the high intraocular pressure is caused by glaucoma.
30 . The method of claim 23 performed as a standalone procedure, or performed in conjunction with cataract removal, canaloplasty, or another glaucoma treatment procedure.
31 . The method of claim 23 , wherein the tissue grabber is bladeless.
32 . The method of claim 23 , wherein the lower foot comprises a central longitudinal axis that is transverse to the longitudinal axis of the shaft.
33 . The method of claim 23 , wherein the groove comprises a closed back, and the closed back is rounded.
34 . The method of claim 23 , wherein the tissue grabber comprises an upper foot and the groove is formed between the lower foot and the upper foot.