# US 8,491,549 B2 · Ophthalmic microsurgical system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,491,549 B2 - Document ID: US8491549B2 - Status: Granted - Kind: B2 - Application number: 10/496,254 - Filed: 2002-11-21 - Published: 2006-07-06 - Granted: 2013-07-23 - Earliest claimed: 2001-11-21 - Assignees: iScience Interventional Corporation - Applicants: Stanley R. Conston; Ronald K. Yamamoto - Inventors: Stanley R. Conston; Ronald K. Yamamoto - Web page: https://patentgrep.com/patent/US8491549B2 ## CPC - A61B 17/32002: {with continuously rotating, oscillating or reciprocating cutting instruments} - A61B 17/3421: {Cannulas} - A61F 9/00763: {with rotating or reciprocating cutting elements, e.g. concentric cutting needles (atherectomy cutting instruments A61B17/3207; endoscopic cutting instruments A61B17/320016)} - A61F 9/00781: {Apparatus for modifying intraocular pressure, e.g. for glaucoma treatment (drainage implants in general A61M27/002)} - A61F 9/0133: {Knives or scalpels specially adapted therefor} - A61B 2017/00867: {shape memory effect} - A61B 2017/305: {Tweezer like handles with tubular extensions, inner slidable actuating members and distal tools, e.g. microsurgical instruments} - A61B 2017/320044: {Blunt dissectors} - A61B 2090/306: {using optical fibres} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract An ophthalmic microsurgical system is described for treatment of eye diseases, such as glaucoma, using minimally invasive surgical techniques. The microsurgical system includes a thin walled outer sheath microcannula 1 slidably disposed about an inner member 4, which extends slightly beyond the distal end of the microcannula 1. The inner member 4 may be straight or curved and may optionally include a surgical instrument and/or a sensor or signaling beacon. The microsurgical system is used in a surgical procedure for opening Schlemm's Canal to provide drainage of aqueous fluid in order to relieve excess intraocular pressure that results from glaucoma and other diseases of the eye. ## Claims ### Claim 1 A microcannula based microsurgical system designed to operate within a tissue tract of the eye, comprising: a flexible tubular outer sheath with an outer diameter of 250 microns or less, with proximal and distal ends, to fit within the tissue tract; a proximal connector on the outer sheath for introduction of materials and tools; and an inner member with a proximal end and a distal tip, wherein the tip is restricted from advancement past a predetermined length from the outer sheath, with the outer sheath and inner member sized such that the inner member fits slidably within the outer sheath and may be removed separately from the outer sheath while in the tissue tract. ### Claim 2 (depends on 1) A microsurgical system of claim 1, wherein the tissue tract is Schlemm's Canal of the eye. ### Claim 3 (depends on 1) A microsurgical system of claim 1, wherein the tissue tract is created by the flexible outer sheath and inner member. ### Claim 4 (depends on 1) The microsurgical system of claim 1, wherein the microsurgical system provides blunt dissection of the tissue tract. ### Claim 5 (depends on 1) The microsurgical system of claim 1, wherein the flexible tubular outer sheath comprises polyimide or a fluoropolymer. ### Claim 6 (depends on 1) The surgical system of claim 1, wherein the flexible tubular outer sheath is curved in the range of 10-15 mm diameter. ### Claim 7 (depends on 1) The microsurgical system of claim 1, wherein the inner member comprises nickel titanium alloy. ### Claim 8 (depends on 1) The microsurgical system of claim 1, wherein the inner member comprises tungsten. ### Claim 9 (depends on 1) The microsurgical system of claim 1, wherein the inner member is curved in the range of 10-15 mm diameter. ### Claim 10 (depends on 1) The microsurgical system of claim 1, further comprising a tool to cut or ablate tissues that interchanges with the inner member to position the tool tip to a predetermined position from the tip of the flexible tubular outer sheath. ### Claim 11 (depends on 1) The microsurgical system of claim 1, wherein the inner member has a distal tip that is shaped for tissue dissection. ### Claim 12 (depends on 11) The microsurgical system of claim 11, wherein the distal tip comprises a multi-faceted shape or a tapered conical shape. ### Claim 13 (depends on 11) The microsurgical system of claim 11, wherein the distal tip is sharpened for tissue penetration. ### Claim 14 (depends on 11) The microsurgical system of claim 11, wherein the distal tip is shaped to provide for controlled surgical penetration of the trabecular meshwork. ### Claim 15 (depends on 14) The microsurgical system of claim 14, wherein the distal tip advances and penetrates the trabecular meshwork from a 45 to 135 degree direction from an axis of the outer sheath. ### Claim 16 (depends on 1) The microsurgical system of claim 1, wherein the outer sheath additionally comprises a plurality of markers set at regular intervals such that each marker is spaced from adjacent markers by a fixed distance along the outer sheath to provide depth measurement. ### Claim 17 (depends on 1) The microsurgical system of claim 1, wherein the inner member comprises a sensing means. ### Claim 18 (depends on 1) The microsurgical system of claim 1, wherein the inner member comprises a signaling means. ### Claim 19 (depends on 18) The microsurgical system of claim 18, wherein the signaling means is an optical fiber. ### Claim 20 (depends on 19) The microsurgical system of claim 19, wherein the optical fiber directs illumination away from an axis of the microcannula at an angle of 45 to 135 degrees. ### Claim 21 (depends on 20) The microsurgical system of claim 20, wherein the optical fiber directs illumination to coincide with the target of an inner member directed away from the axis of the microcannula at an angle of 45 to 135 degrees. ### Claim 22 (depends on 19) The microsurgical system of claim 19, wherein the optical fiber directs illumination away from the axis of the microcannula at an angle of approximately 90 degrees. ### Claim 23 (depends on 1) The microsurgical system of claim 1, wherein the system is sized to deliver an implant to the tissue tract by action of the inner member. ### Claim 24 (depends on 23) The microsurgical system of claim 23, wherein the implant is a stent-like tube.