Micro-surgical instrument for ophthalmology

Abstract

To provide a tiny ophthalmologic surgical instrument equipped with a trocar having a rigid hollow shaft for penetrating the sclera or other tissues.SOLUTION: A tiny surgical instrument 100 includes a trocar 200 having a rigid hollow shaft 206 in which a lumen 208 extending from a proximal end to a distal end 210 of the shaft. The instrument further includes a composite microcannula 300 that slidably engages with the trocar in the lumen. The microcannula includes a light guide and a flexible hollow tube 302 with an outer diameter smaller than the inner diameter of the lumen of the trocar. Another embodiment includes that the microcannula is disposed in the lumen of the trocar, that the end part of the trocar is illuminated by illuminating the end part of the microcannula, that the trocar is caused to advance from an approach point selected in the eye to a structure selected in the eye, and that the illuminated end part of the microcannula is extended inside the structure selected from the trocar.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Each embodiment relates to a surgical device for the treatment of eye disorders such as glaucoma. [Background technology]

[0002] (Related Applications) This application is a continuation-in-part of co-pending U.S. Patent Application No. 15 / 892,833, filed February 9, 2018, which is incorporated herein by reference in its entirety, which claims priority to U.S. Provisional Patent Application No. 62 / 574,136, filed October 18, 2017, which is incorporated herein by reference in its entirety.

[0003] Aqueous humor is a clear, watery fluid produced within the eye that fills the anterior and posterior chambers of the eye, transports necessary materials to the eye's tissues, and helps maintain the eye's spherical shape through fluid pressure. Aqueous humor leaves the eye through a fluid drainage system that includes the trabecular meshwork and Schlemm's canal, which are circumferential, porous fluid channels that connect to collecting ducts and veins. Blockage or narrowing of any part of the eye's drainage system can cause increased intraocular pressure, a condition that can be associated with decreased vision and eye diseases such as glaucoma.

[0004] Surgical treatments may be used to improve the flow of aqueous humor and thereby reduce intraocular pressure. Some surgical treatments involve a relatively large incision in the sclera, the tough white outer layer of the eye, and folding back a portion of the tissue to expose the trabecular meshwork or other portions of the aqueous humor flow path. The exposed portion of the drainage system can then be repaired by removing tissue or forming a new drainage canal. The incision in the sclera may cause a loss of fluid pressure within the eye and collapse of one or more of the chambers. It may be necessary to inject a viscoelastic fluid into one of the chambers to support the natural shape of the eye. Viscoelastic fluids have a viscosity that changes under dynamic and static flow conditions, flowing with a relatively low viscosity when subjected to shear stress and assuming a gel-like high viscosity under static conditions.

[0005] Surgical treatments involving incisions in the eye may increase the risk of postoperative complications such as infection and scar tissue formation. Other less invasive treatments for the eye have been developed. For example, a microcannula may be passed through a portion of the drainage system of the eye to remove blockages or open narrowed fluid pathways, thereby improving the flow of aqueous humor. In addition, it may be advantageous to deliver drugs, drug-eluting devices, or drug-eluting substances to tissue structures. In particular, it may be beneficial to deliver drugs or drug-eluting devices to Schlemm's canal, since Schlemm's canal is outside of the immune-privileged sites present in the body of the human eye. The microcannula may include a flexible hollow tube, which has an outer diameter small enough to allow the microcannula to be inserted into Schlemm's canal or other portions of the drainage system of the eye. The microcannula may be sufficiently flexible to follow the curvature of Schlemm's canal or other portions of the drainage system when pushed from outside the eye, for example, through a surgically created tissue fold as described above, or through a puncture in the sclera. Microcannulas are used to mechanically expand selected portions of the drainage tract within the eye. or may be used to inject substances, objects, fluids, drugs, or viscoelastics to apply fluid pressure to improve flow through a portion of the eye's drainage system, or a microsurgical cutting, penetrating, or grasping instrument may be passed through the microcannula to guide the instrument to the portion of the eye to be surgically repaired. Summary of the Invention [Problem to be solved by the invention]

[0006] Some microsurgical instruments include a microcannula slidably engaged with a hollow, flexible outer sheath. The flexible outer sheath can be used to position the microcannula at an entry point into the interior of the eye, where the microcannula is threaded through the lumen of the flexible outer sheath, which is held stationary relative to the eye. The end of the microcannula can extend beyond the end of the sheath to enter a selected portion of the eye. However, the flexibility of the outer sheath can make it difficult to penetrate the sclera or other tissue with the sheath so that the microcannula can enter a drainage structure or other treatment site in the eye. An incision or puncture with another instrument may be required to allow the flexible sheath to be accurately positioned for placement and guidance of the microcannula. Alternatively, the microcannula can be provided with a tip shaped for tissue penetration, but this may limit the use of the microcannula in applications that deliver products to the interior of the eye. [Means for solving the problem]

[0007] An example of an embodiment of a device includes a trocar and a composite microcannula. The example trocar includes a rigid shaft having a proximal end and a distal end. The rigid shaft may have a lumen formed therein extending from the proximal end to the distal end. The distal end of the rigid shaft of the trocar may be shaped for penetration of tissue.

[0008] The composite microcannula may be disposed within the lumen of the trocar. An example of a composite microcannula may comprise a flexible hollow tube having an outer diameter smaller than the inner diameter of the lumen of the trocar. An example of a composite microcannula may further comprise a light guide.

[0009] Another example of an embodiment of the device includes a trocar for ophthalmic surgery. The example trocar includes a rigid hollow shaft having a distal end shaped for penetration of tissue. The hollow shaft has a lumen formed therein extending from the distal end of the hollow shaft to the proximal end of the hollow shaft. The example trocar further includes a transition structure attached to the proximal end of the hollow shaft. The transition structure may have an opening formed therein for receiving a composite microcannula within the lumen. The example trocar may further include a light source arranged to illuminate the distal end of the rigid hollow shaft. A distal edge of the lumen of the hollow shaft may be smoothed to inhibit abrasion and / or cutting of solid objects passing through the lumen and out of the trocar. The example trocar may further include a tab extending outwardly from the transition structure.

[0010] An example of a method embodiment includes placing a distal end of a composite microcannula within a lumen of a trocar; illuminating the distal end of the trocar by illuminating the distal end of the composite microcannula; selecting a trocar entry point on the eye and positioning the trocar at the selected entry point; advancing the trocar at the selected entry point until the illuminated distal end of the trocar is observed to have entered a selected structure within the eye; and transitioning from illuminating the distal end of the trocar to illuminating tissue outside the trocar by extending the composite microcannula from the distal end of the trocar toward a target site within the eye.

[0011] Another example of the device includes a handpiece, an actuator slidably coupled to the handpiece, an insert slidably coupled to the handpiece, a hollow tube attached to the actuator, and a wire threaded through the hollow tube, with a first end of the wire attached to the handpiece and a second end of the wire attached to the insert.

[0012] Another example of an ophthalmic surgical trocar includes a shaft (particularly a rigid hollow shaft) having a lumen that accommodates a cannula (particularly a composite microcannula), the shaft having a distal end shaped for penetration of tissue.

[0013] The distal end of the shaft can be beveled or tapered. Alternatively or additionally, the distal end of the shaft is configured to provide a single puncture hole upon penetration of tissue.

[0014] The inner surface of the distal end of the shaft can be smoother than at least a portion of the inner surface of the remainder of the shaft. Additionally, the distal edge of the shaft can be smoother than at least a portion of the inner surface of the remainder of the shaft. The outer surface of the shaft can include a lubricious coating.

[0015] The trocar may include a light guide and / or a light source adapted to illuminate the distal end of the shaft. In particular, an end of the light guide may be used to illuminate the distal end of the shaft and / or tissue. The end of the light guide may have a larger cross-section than at least a portion of the remainder of the light guide and / or the other end of the light guide may be connectable to a light source that emits visible and invisible light.

[0016] The light guide can be attached to the shaft or can be an integral part of the shaft.

[0017] Another example of a device may include the trocar and cannula described above. The cannula may be a composite microcannula and / or may be disposed within the lumen of the trocar.

[0018] The stiffness of the cannula can be less than the stiffness of the shaft. The diameter of the cannula can be in the range of 100 microns to 250 microns.

[0019] The cannula may have a lumen extending between both ends of the cannula. When the cannula extends from the distal end of the hollow shaft, the product can be introduced into the tissue through the cannula (specifically through the lumen of the cannula). During introduction of the product into the tissue, the shaft is maintained in the same position.

[0020] The device may include a transition structure (particularly a trocar connector). The trocar (particularly the proximal end of the shaft) can be connected to the transition structure. Further, the cannula can extend through the transition structure.

[0021] The light guide or another light guide may be coupled to the cannula, in particular, the light guide or another light guide may be attached to or be an integral part of the cannula, or the light guide may be positioned such that the end of the shaft is illuminated regardless of the presence or placement of the cannula.

[0022] The light guide and / or another light guide can be connected to a light source. The device can include a mirror positioned to direct light from the light source towards the proximal end of the shaft.

[0023] The lumen of the cannula can be fluidly connected to an injector of a substance, particularly a viscoelastic substance. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view of an example embodiment of a microsurgical instrument comprising a trocar with a rigid hollow shaft and a flexible composite microcannula. [Diagram 2]FIG. 13 is a top view of an example trocar according to an embodiment. [Diagram 3] FIG. 3 is a side view of the example trocar of FIG. 2. [Figure 4] 4 is a cross-sectional view AA showing the example of the trocar of Figures 1 to 3. The cutting line marked AA in Figure 3 indicates the position and observation direction for the cross-sectional view of Figure 4. [Diagram 5] FIG. 5 is an enlarged partial cross-sectional view B of the rigid hollow shaft of FIGS. 1-4, showing an example of a distal end shaped for tissue penetration and further showing an example of a smoothed distal edge at the lumen of the trocar. The location of view B in FIG. 5 is shown by the dashed line in FIG. 4. [Figure 6] FIG. 1 is a partial top view of an example of a composite microcannula in accordance with an embodiment of a microsurgical instrument. [Figure 7] 7 is a cross-sectional view CC of the example composite microcannula of FIG 6. The location and viewing direction for cross-sectional view CC of FIG 7 is indicated by longitudinal section line CC in FIG 6. [Figure 8] 8 is a cross-sectional view DD of an example of a composite microcannula of FIG 6. The location and viewing direction for cross-sectional view DD of FIG 8 is indicated by transverse section line DD in FIG 6. [Figure 9] 9 is an alternative cross-sectional view DD showing another example of a composite microcannula in accordance with an embodiment of a microsurgical instrument.The location and viewing direction for the alternative cross-sectional view DD of FIG. 9 is shown by the transverse cut line DD in FIG. [Figure 10] 10 is an alternative cross-sectional view DD of another example of a composite microcannula in accordance with an embodiment of a microsurgical instrument.The location and viewing direction for the alternative cross-sectional view DD of FIG. [Figure 11] 11 is an alternative cross-sectional view DD showing another example of a composite microcannula in accordance with an embodiment of a microsurgical instrument. The location and viewing direction for the alternative cross-sectional view DD of FIG. [Figure 12]FIG. 2 is an alternative cross-sectional view AA of another example trocar, further illustrating an example of a composite microcannula positioned proximally offset from the distal end of the trocar, and also illustrating an example of an illuminated distal end of the trocar. [Figure 13] Continuing the example of FIG. 12, FIG. 13 illustrates an example of an illuminated distal end of a composite microcannula extending from the distal end of a trocar lumen. [Figure 14] 11A-11D are alternate cross-sectional views of another example composite microcannula, in which two light guides are provided within the interior longitudinal cavity of the flexible hollow tube of the composite microcannula. [Figure 15] FIG. 6 is an alternative cross-sectional view DD showing another example of a composite microcannula with two light guides, one light guide disposed inside the flexible hollow tube of the composite microcannula and the other light guide abutting the outer surface of the flexible hollow tube. [Figure 16] FIG. 5 is an alternative cross-sectional view (DD) of another example of a composite microcannula with two light guides, one light guide disposed inside the flexible hollow tube of the composite microcannula and the other light guide disposed between the hollow tube and the outer sleeve. [Figure 17] FIG. 5 is an alternative cross-sectional view DD of another example of a composite microcannula with two light guides, the first light guide being disposed inside the flexible hollow tube of the composite microcannula and the second light guide being held against the hollow tube by an outer coating applied to the second light guide and the flexible hollow tube. [Figure 18] FIG. 13 is a block diagram illustrating another embodiment of the device that includes a positioner for displacing the composite microcannula relative to the trocar and optionally includes a fluid injector for introducing fluid into the composite microcannula. [Figure 19] FIG. 1 is a top view of an example of an embodiment of a microsurgical instrument including a positioner and a trocar. [Figure 20]20 is a cross-sectional view EE of an example of the positioner of Fig. 19. The position and viewing direction for cross-sectional view EE of Fig. 20 is shown by the longitudinal section line EE in Fig. 19. [Figure 21] FIG. 1 is a perspective view of an example of an embodiment of a microsurgical instrument with a positioner showing a distal tip of a trocar passing through the sclera of the eye and entering Schlemm's canal, and shows an example of light emitted from an illuminated distal end of the trocar to pinpoint the position of the trocar. [Figure 22] FIG. 22 is a perspective view showing an example of a microsurgical instrument and trocar in a relative position to Schlemm's canal similar to that of FIG. 21, further illustrating an example of an illuminated distal tip of a composite microcannula extending from the trocar along a circumferential path of Schlemm's canal. [Diagram 23] FIG. 2 is another alternative cross-sectional view AA of the example trocar of FIG. 1, illustrating an example of a composite microcannula having a light guide passing through the lumen of the trocar, and further illustrating an optional second light guide disposed within the lumen, separate from the light guide within the composite microcannula. [Figure 24] FIG. 24 is a partial perspective view of an example trocar with a composite microcannula and a second light guide similar to the example of FIG. 23, showing an example of illuminated distal ends of the trocar and composite microcannula spaced apart from one another along a circumferential path of Schlemm's canal. [Diagram 25] 11A-11D are alternate cross-sectional views DD showing an example of an embodiment of a composite microcannula carrying an optional fluid deliverable and an optional solid deliverable within a flexible hollow tube. [Figure 26] FIG. 1 is a perspective view showing an example of a trocar entry point marking device. [Figure 27] 27 shows an example of a marking surface of a marking pad in the trocar entry point marking tool of FIG. 26. [Figure 28] FIG. 28 is a side view showing the example of a trocar entry point marking tool of FIGS. 26-27. [Figure 29]FIG. 29 illustrates an example of the sclera and iris of a human eye, depicting an example of a tangential pattern formed by the trocar entry point marking tool of FIGS. 26-28. [Diagram 30] 1 illustrates an example of steps involved in a method for inserting a trocar through the sclera of an eye and advancing a composite microcannula from the trocar into a structure such as Schlemm's canal. [Diagram 31] FIG. 13 is a partial top view of another example of a composite microcannula in accordance with an embodiment of a microsurgical instrument. [Diagram 32] 32 is a cross-sectional view FF of the example composite microcannula of FIG 31. The location and viewing direction for cross-sectional view FF of FIG 32 is indicated by the longitudinal section line FF in FIG 31. [Diagram 33] FIG. 33 is a cross-sectional view GG of the example composite microcannula of Figures 30-31. The location and viewing direction for cross-sectional view GG of Figure 33 is indicated by transverse section line GG in Figure 31. [Diagram 34] FIG. 1 is a top view of an example of an embodiment of a microsurgical instrument including a positioner and a trocar. [Diagram 35] FIG. 35 is a side view of two examples of the microsurgical instrument of FIG. 34, with the upper device showing the composite microcannula in an example of a retracted position and the lower device showing the composite microcannula in an example of an extended position. [Diagram 36] 35A-35C are cross-sectional views of the example microsurgical instrument shown in cross-sectional view HH for a retracted position of the composite microcannula and in cross-sectional view KK for an extended position of the composite microcannula, the locations of which are indicated by section lines HH and KK in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Examples of embodiments according to the present invention are described below. A trocar with a rigid hollow shaft with a distal end shaped for tissue penetration is configured to puncture biological tissue, such as the sclera of an eye, to create a very small entry point into the tissue for a composite microcannula threaded into the lumen of the trocar. The composite microcannula, which may also be referred to herein as a composite microcatheter, includes a light guide for illuminating the distal end of the microcannula. A light source can be coupled to the composite microcannula and / or trocar and directed through the light guide into the lumen of the trocar to illuminate the distal end of the rigid hollow shaft, thereby allowing precise detection of the location of the distal end of the trocar and a visual indication of the trocar's entry into a structure within the eye and the location of the distal end of the composite microcannula as it is advanced towards a target site to be treated. The illuminated distal end of the composite microcannula can be used to detect when the microcannula deviates from the preferred path, for example, by straying from the preferred path within Schlemm's canal and entering another chamber or duct, such as the collecting duct or other portion of the ocular drainage system.

[0026] Each embodiment is effective in providing a visual indication of the location of the distal end of the trocar by observing light emitted from the trocar passing through tissue, which may include the sclera, trabecular meshwork, or other tissue, including tissues not associated with the eye. The light from the trocar passing through the sclera or other tissue further indicates the direction of trocar movement. The location and direction of movement of the composite microcannula can also be precisely detected by visual observation of the light emitted from the tip of the microcannula. The embodiment can be precisely guided into tissues and / or tissue spaces, such as, but not limited to, the trabecular meshwork, Schlemm's canal, and collecting duct. Conversely, the embodiment can be precisely guided to specifically avoid entering selected tissues or tissue spaces. Tissues within the eye, as well as the location and direction of movement of the embodiment can be observed by direct observation, a camera, a gonioprism, other visual aids, or any combination of these devices and methods.

[0027] In some embodiments, the second light guide allows the distal end of each of the trocar and the composite microcannula to be illuminated independently and optionally simultaneously. In other embodiments, the composite microcannula can deliver fluid and / or solid objects to a target site in the eye. Examples of fluid deliverables include, but are not limited to, drugs such as gene therapy drugs, stem cell drugs, and other fluid-based drugs, viscoelastic fluids, water, and saline. Examples of solid deliverables include, but are not limited to, devices, particles, nanoparticles, small devices including solid deliverables examples for drug elution, microsurgical instruments such as forceps, instruments for tissue penetration and / or incision, stents, light guides, and wires. As used herein, a light guide refers to an optical element capable of transmitting electromagnetic energy received at an input surface to an output surface through an intervening optical medium. Examples of light guides include, but are not limited to, one or more mirrors arranged to direct a light beam from a light source to a destination, flexible optical fibers, optical fiber bundles, and rigid light pipes.

[0028] Some embodiments include a positioner that displaces the composite microcannula relative to the distal end of the trocar. The positioner may optionally include a microcannula displacement mechanism configured to extend, and optionally also retract, the composite microcannula. The positioner may further optionally include a fluid injector configured to move fluid from a fluid reservoir into the composite microcannula and possibly into a selected target site within the eye. Some embodiments of the positioner include a light source positioned to emit light into the light guide of the composite microcannula and optionally into a second light guide coupled to the trocar, if one is provided. The positioner can provide precise advancement and / or retraction of the composite microcannula without disturbing the microcannula's entry point into the eye, potentially reducing the time required to complete a therapeutic procedure and reducing the risk of eye tissue damage.

[0029] Each embodiment of the ophthalmic microsurgical instrument can be configured to smoothly and continuously transition from illuminating the distal end of the trocar to illuminating the tissue outside the trocar, thereby allowing for very precise detection of the position of the trocar and composite microcannula relative to structures within the eye. The very small puncture hole formed by the trocar in the sclera or other part of the eye contrasts with the relatively large incision required in conventional surgical methods that lift a folded portion of tissue from the sclera to access structures within the eye. The small puncture hole reduces patient discomfort and the risk of post-operative complications such as scarring and infection. Surgical site preparation, monitoring, and closure are quicker and less complicated than methods using scleral incisions, potentially allowing each embodiment to be used with a relaxed level of sterility and patient monitoring compared to that which would be practiced in an operating room for a surgical procedure, potentially allowing for faster recovery and healing of the patient after the surgical procedure.

[0030] An example of an embodiment of a microsurgical instrument is shown in Figure 1. The illustrated embodiment 100 includes a trocar 200 configured to receive a composite microcannula 300. The composite microcannula 300 is slidably engageable with the trocar 200 and passes through a trocar connector 222 located at the proximal end 204 of the trocar, through a transition structure 214, and through a lumen 208 formed in a rigid hollow shaft 206 that extends from the transition structure 214 to a distal end 210 of the trocar 200. The rigid hollow shaft 206 is preferably formed with a distal end 210 shaped for penetration of tissue. One or more optional tabs 216 may be attached to or formed as an integral part of the trocar connector 222 and / or the transition structure 214.

[0031] In the example of Figure 1, the composite microcannula 300 is shown to include several bends and curves, illustrating the flexibility of the hollow tube 302 that makes up most of the length of the composite microcannula. The flexibility of the composite microcannula allows the microcannula to conform to the curved walls of intraocular structures, such as Schlemm's canal, without puncturing or damaging the walls of the structures. One embodiment of the composite microcannula 300 has a diameter of 3.0 x 10 -11 kN-m 2 ~2.9×10 -10 kN-m 2 The composite microcannula may be comprised of segments of microcannula having a bending stiffness in the range of 1.5×10 to 1.5×10. The portions of the composite microcannula near the distal and / or proximal ends can optionally be more rigid than other portions of the composite microcannula. The stiff hollow shaft 206 of the trocar 200 is substantially stiffer than the composite microcannula and is sufficiently stiff to easily penetrate the sclera or other tissue within the eye. -8 kN-m 2 Trocars having a bending stiffness greater than the preferred minimum may eliminate the need for a separate surgical instrument to form a puncture through the exterior surface of the eye.

[0032] The composite microcannula 300 may include an optional microcannula connector 314 at the proximal end 310 of the flexible hollow tube 302. The microcannula connector may include a connection for introducing a deliverable into the composite microcannula and a connection for coupling light from a light source to the composite microcannula. A liquid, solid, or gas deliverable introduced at the proximal end 310 passes through the hollow tube 302 to the composite microcannula. The light can be conveyed to the distal end 308 of the microcannula and delivered to a target site within the eye. Light entering the proximal end 310 travels to the distal end 308, forming the illuminated distal end 326 of the composite microcannula. An optional light diffuser 311 may be provided at the distal end 308, which diffuses the light in multiple directions to indicate the precise location of the distal end of the composite microcannula as it travels through the canals and chambers within the eye. Light can travel from the proximal to the distal end of the composite microcannula by internal reflection from the walls of the flexible hollow tube 302, through liquid introduced within the hollow tube 302, or through one or more light guides included in some embodiments of the composite microcannula.

[0033] An example of an embodiment of a trocar 200 is shown in a top view in FIG. 2 and a side view in FIG. 3. In the example of FIG. 3, the optional gripping portion 216 shown in FIG. 2 is omitted. The trocar connector 222 located at the proximal end 204 of the trocar 200 may be a luer connector, such as a slip-fit ​​or twist-lock luer connector. Other connectors capable of forming a leak-proof seal may alternatively be used. The rigid hollow shaft 206 of the trocar 200 is attached to the transition structure 214. The lumen 208 of the rigid hollow shaft 206 is in fluid communication with cavities in the transition structure and in the trocar connector, allowing fluid to be introduced into the lumen 208. The lumen 208 of the trocar 200 extends through a distal end 210 shaped for penetration of tissue.

[0034] Sectional view AA of Figure 4 and the enlarged portion of Figure 5 depict some internal details of an example trocar 200 in accordance with an embodiment. A rigid hollow shaft 206 is rigidly held by a transition structure 214 attached to a trocar connector 222. A lumen 208 within the rigid hollow shaft 206 is in fluid communication with a cavity 224 within the trocar connector 222. The cavity 224 may be formed with a conical microcannula guiding surface 221 located near the proximal end of the hollow shaft 206. The conical surface 221 may deflect a composite microcannula into the lumen 208 through an opening 223 formed in the transition structure 214 located near the distal end of the cavity 224.

[0035] The distal edge 212 of the lumen 208 is preferably smoothed to eliminate sharp points, for example by rounding the edge 212 all around the distal end of the lumen. The smoothed distal edge 212 inhibits abrasion or cutting of material from the composite microcannula as the microcannula slides over the distal edge of the trocar lumen. If not smoothed, the distal edge of the trocar lumen may be sharp enough to remove material from the composite microcannula. Reducing the amount of material that is cut or abraded from the composite microcannula reduces the undesirable deposition of such material in the eye.

[0036] 5B further illustrates examples of an outer diameter 219 of the rigid hollow shaft 206 and an inner diameter 218 of the lumen 208 within the rigid hollow shaft 206. The outer diameter 219 can be in the range of about 200 microns to about 700 microns. For example, some embodiments of the trocar include a rigid hollow shaft with an outer diameter 219 of 450 microns. In other embodiments of the trocar, the outer diameter 219 of the rigid hollow shaft is 250 microns. The inner diameter 218 is preferably greater than the maximum transverse dimension 306 of a composite microcannula configured to slide through the lumen. The maximum transverse dimension 306 may be, for example, the outer diameter 306 of the flexible hollow tube 302, the maximum transverse dimension 306 across the tube 302 and an outer coating 321 applied to the tube, the maximum transverse dimension 306 across the hollow tube 302 and an external light guide 304 adjacent to the tube, or the outer diameter 306 of a sleeve 320 surrounding the tube 302.

[0037] An example of an embodiment of a composite microcannula 300 is shown in a top view in FIG. 6, a longitudinal cross-section view CC in FIG. 7, and optional transverse cross-section views DD in FIGS. 8-11. As suggested in FIGS. 6, 7, and 8, the light guide 304 may be disposed within a longitudinal cavity 303 that extends from the proximal end 310 to the distal end 308 of the flexible hollow tube 302. The longitudinal cavity 303 in the composite microcannula 300 may also be referred to as the lumen 303 of the composite microcannula. The cavity 303 may function as a fluid path 324 for fluids introduced into the flexible hollow tube 302. Deliverables introduced into the composite microcannula may follow the fluid path 324 as they travel from the proximal end 310 to the distal end 308.

[0038] The light guide 304 may be formed separately from the flexible hollow tube, as suggested in the examples above. Alternatively, the light guide may be formed as an internal layer of the flexible hollow tube 302, as shown in the examples of Figures 31, 32, and 33. The light guide 304 may be provided as a concentric layer adjacent to the cavity 303 in the composite microcannula 300. The refractive index of the material of the light guide 304 is preferably sufficiently different from the refractive index of the material of the flexible hollow tube 302 to allow light from the light source to be efficiently coupled to the distal end 308 by internal reflection through the light guide. The layers of material that make up the light guide 304 may be formed by molding or chemical deposition, or may be formed by mechanically inserting a hollow tube into the flexible hollow tube 302. Although the figures show an example of a light guide made of a single layer of material, the light guide may alternatively be composed of several layers of material, each having a selected refractive index value, or may be configured to vary in refractive index with distance from the edge of the light guide.

[0039] Figures 31, 32, and 33 further show an example of an optical diffuser 311 having an outer diameter 312 that is smaller than the outer diameter of the optical diffuser 311 of the examples of Figures 6 and 7. The optical diffuser 311 may alternatively be formed as a rounded end of a flexible hollow tube 302, with the diffuser having a radius equal to half the diameter 313 of the flexible hollow tube.

[0040] A second light guide and / or other liquid or solid deliverables can be passed through the cavity 303 surrounded by the light guide 304. In some embodiments, the light guide 304 completely surrounds the cavity 303 within the flexible hollow tube 302. Alternatively, the light guide 304 may not completely surround the cavity, for example, the light guide may be formed as a fractional piece of hollow tube extending longitudinally a half, quarter, or other proportion of the entire hollow tube.

[0041] The outer diameter 306 of the composite microcannula 300 may be the largest diameter of the composite microcannula, such as, for example, diameter 312 in FIG. 6. The outer diameter 306 is, for example, the larger of the outer diameter 312 of an optional optical diffuser 311 located at the distal end 308 and the outer diameter 313 of the hollow tube 302, and is preferably smaller than the inner diameter 218 of the lumen 208 within the trocar 200.

[0042] The distal end 308 of the composite microcannula corresponds to the illuminated end 326 when light incident on the proximal end 310 of the light guide 304 emerges from the distal end 308. As suggested in Figures 6 and 7, the distal end 308 of the composite microcannula may be rounded to reduce tissue trauma and to diffuse the light from the optical diffuser 311 in multiple directions to improve visibility of the illuminated end 326. The outer diameter 312 of the optical diffuser may be greater than the outer diameter 313 of the hollow tube 302. Alternatively, both diameters (312, 313) may be approximately equal.

[0043] In some embodiments, the length of the flexible segment 322 of the composite microcannula 300 The length of the flexible segment 322 may be several millimeters longer than the circumferential length of Schlemm's canal. The circumferential length of Schlemm's canal in the human eye is approximately 36 mm. In some embodiments of the composite microcannula 300, the length of the flexible segment 322 may be greater than 40 mm (1.6 inches). The length of the flexible segment 322 can optionally be substantially longer than the circumferential length of Schlemm's canal, for example, to allow the composite microcannula to be connected to a light source or fluid injection device, or to provide a convenient length outside the proximal end of a trocar so that the composite microcannula can be grasped with forceps or fingers.

[0044] Alternatively, the length of the flexible segment 322 of the composite microcannula 300 may be approximately 20 mm so that catheterization of Schlemm's canal can be performed in two insertions: the first insertion may enter approximately half the length of Schlemm's canal in a clockwise direction, and the second insertion may enter the other half of Schlemm's canal in a counterclockwise direction.

[0045] In the example composite microcannula 300 of Figure 8, a light guide 304 is disposed within the longitudinal cavity 303. The diameter of the light guide is small compared to the inner diameter 307 of the flexible hollow tube 302. The outer diameter 306 of the composite microcannula 300 can be the outer diameter of the hollow tube 302.

[0046] In the example of composite microcannula 300 of Figure 9, the light guide 304 is disposed on the exterior surface of the flexible tube 302, leaving space available inside the flexible tube 302 for conveying a deliverable through the composite microcannula. In the example of Figure 9, the outer diameter 306 of the composite microcannula includes the dimensions of the flexible tube 302 and the light guide 304.

[0047] 10 and 11 show further examples of composite microcannula 300 in accordance with the embodiment 100 of the microsurgical instrument. In the composite microcannula 300 illustrated in FIG. 10, the light guide 304 is located outside the cavity 303 in the flexible hollow tube 302. An outer sleeve 320 surrounds the light guide 304 and the flexible tube 302. The outer diameter 306 of the composite microcannula may correspond to the outer diameter of the sleeve 320 in FIG. 10. In FIG. 11, an example of a coating 321 is applied to the light guide 304 and the flexible hollow tube 302. The outer diameter 306 of the composite microcannula along the flexible segment includes the dimensions of the hollow tube 302, the light guide 304, and the outer coating 321. In both the embodiments illustrated in FIG. 10 and FIG. 11, the entire inner diameter 307 of the hollow tube 302 is available for delivery of the deliverables within the longitudinal cavity 303.

[0048] The composite microcannula can be positioned within the lumen of the trocar to illuminate the distal end of the trocar while the trocar is inserted into the eye. Figures 12 and 13 show alternative configurations of the transition structure 214 and exemplary positions of the composite microcannula. In Figure 12, the composite microcannula is positioned to illuminate the distal end 202 of the trocar's rigid hollow shaft 206. The distal end 308 of the composite microcannula, which in the example of Figures 12-13 is also the illuminated end 326 of the microcannula, can be placed within the lumen of the trocar a suitable offset distance 626 away from the distal end 202 of the trocar. Light 614 emitted from the distal end of the composite microcannula emerges from the distal end of the trocar as light 612 that is diffused over a wide range of angles due to internal reflection within the trocar lumen, thereby making the tip of the trocar visible from many different viewing directions. The illuminated distal tip 220 of the trocar can be used to pinpoint the exact location of the tip of the trocar within the ocular tissue, for example, a readily perceptible change in brightness in the emitted light 612, which can be seen through the trabecular meshwork by gonioscopy, indicates when the distal tip of the trocar has passed through the sclera and entered Schlemm's canal.

[0049] By advancing the illuminated distal tip 326 of the composite microcannula out of the lumen of the trocar, a smooth transition is made from illuminating the tip of the trocar to illuminating the tissue outside the trocar. In the example of Figure 13, the light 614 emitted from the illuminated distal tip 326 of the composite microcannula can be spread over a wide range of angles, thereby pinpointing the location of the tip of the composite microcannula within the eye.

[0050] Some alternative embodiments of the composite microcannula include two light guides, as shown in Figures 14-17. In the example of the composite microcannula 300 of Figure 14, the first light guide 304 and the second light guide 412 are disposed within the lumen 303 of the hollow tube 302. According to the example of Figure 15, the first light guide 304 may be located outside the lumen 303 of the hollow tube 302 and the second light guide 412 may be located inside. According to the example of Figure 16, both light guides may be disposed as in Figure 15, and an outer sleeve 320 may surround the flexible hollow tube 302 and the first light guide 304. According to the example of Figure 17, both light guides may again be disposed as in Figure 15, but an outer coating 321 is applied to the first light guide 304 and the flexible hollow tube 302.

[0051] Some embodiments of the microsurgical instrument include a positioner that displaces the composite microcannula relative to the trocar. A block diagram of an alternative embodiment of the microsurgical instrument 100 including a positioner is shown in the example of FIG. 18. The positioner 400 may include a handpiece 420 provided with a microcannula displacement mechanism 425 configured to extend and optionally retract the composite microcannula 300 from the trocar 200. The trocar 200 may be attached to a trocar receiver 422, e.g., a receiver for a luer fitting of the trocar. The composite microcannula may be threaded through a hollow sleeve 433 provided between the trocar receiver 422 and the microcannula displacement mechanism 425. The hollow sleeve 433 may allow for smoother extension and retraction of the composite microcannula by inhibiting buckling or twisting of the flexible portion of the composite microcannula located within the positioner 400 when the microcannula displacement mechanism is actuated. An actuator 424, mechanically linked to a microcannula displacement mechanism 425, allows for manual adjustment of the length of the composite microcannula that extends from the distal end of the trocar.

[0052] An optional light source 328 may be provided internal to the positioner 400. Light output from the light source 328 may be coupled to a microcannula connector 314 attached to the composite microcannula 300. The microcannula connector 314 may optionally be configured to receive light from an external light source 330. In some embodiments, the light source 328 may be positioned to transmit light into the lumen of the trocar 200 through the second light guide 412 and, optionally, through the intervening trocar receiver 422.

[0053] The microcannula connector 314 may optionally be fluidly connected to a fluid injector 446 provided to transfer fluid from a fluid reservoir 442 within the handpiece 420 to the composite microcannula 300. Alternatively, the microcannula connector 314 may be connected to an external fluid injector 448 configured to move fluid from an external fluid reservoir 444 into the composite microcannula 300.

[0054] 19 and 20 show some details of an embodiment 100 of the microsurgical instrument, including the positioner 400. The trocar connector 222, located at the proximal end of the trocar 200, The actuator 424 is slidable into the handpiece 420 along an actuator opening 428 to extend the composite microcannula from the trocar. The actuator 424 is attached to or formed as an integral part of a guide block 426 configured to ride along a guide ridge 430 in the handpiece 420.

[0055] The hollow sleeve 433 may be connected at its proximal end to the guide block 426 and at its distal end to the trocar 200. A composite microcannula (not shown in FIGS. 19-20) may be disposed within the hollow sleeve 433. The hollow sleeve may include a fixed segment 436 attached to or formed as an integral part of the trocar 200 and a movable segment 434 coupled to the actuator block 426, in which case the length 438 of the hollow sleeve 433 includes both the fixed and movable segments. Alternatively, both the fixed and movable segments of the hollow sleeve 433 may be configured as a double-sided, hollow, collapsible and extendable bellows sleeve. The length 438 of the hollow sleeve 433 may change with movement of the composite microcannula 300 relative to the trocar 200.

[0056] An end cap 440 may close the proximal end 416 of the positioner 400. The end cap 440 may be formed with a cap opening 482 that allows the composite microcannula to extend from the proximal end 416.

[0057] 21 and 22 show examples of the location of the trocar entry point in the eye and the extension of the composite microcannula along the circumferential path of Schlemm's canal. Both figures show a perspective view of the positioner 400 in the same position and orientation relative to the eye 1000. Other parts of the generally spherical eye 1000, represented in simplified form in the figures, include the sclera 1002, the iris 1006, the pupil 1016, and the circumferential path of Schlemm's canal 1010 located near the limbus of the eye. Schlemm's canal 1010 comprises a porous, generally circular drainage canal that receives aqueous humor flowing through the trabecular meshwork located near the outer edge of the iris. Schlemm's canal is shown in the figures with hidden lines, representing its approximate location behind the outer surface of the sclera 1002. The cornea, which extends outward from the drawing towards the viewer and above the iris 1006, can be considered to be present in Figures 21 and 22, but is transparent and not depicted. The center 1018 of the pupil 1016 also represents the approximate center of the iris 1006.

[0058] In the examples of Figures 21 and 22, the distal end 202 of the trocar 200 is inserted into the sclera 1002 at a suitable trocar entry point 606, puncturing the sclera with a small hole having a diameter approximately the same as the outer diameter of the rigid hollow shaft 206. The trocar can be advanced in a direction 610 along a tangent 604 to Schlemm's canal 1010. In the example of Figure 21, the distal end 202 of the trocar 200 is positioned immediately after entering Schlemm's canal 1010. The location of the distal end of the trocar is made visible by light 612 emanating from the trocar lumen. In some embodiments 100, the light 612 is emitted from the distal end of a light guide, which is offset from the trocar lumen 208 (see Figure 12) by a selected distance 626. Light 612 emitted from within Schlemm's canal through the sclera can appear as a bright spot in the outer portion of the eye when viewed from outside the eye, and light emitted from within Schlemm's canal through the trabecular meshwork can appear as a well-defined bright spot visible beyond the anterior chamber of the eye. The bright spot is a visual indication of the exact location of the distal end 202 of the trocar 200. In the figure, light 61 emitted from the end of the trocar is 2 and the light emitted from the end of the composite microcannula 614 are shown as short wavy lines. A gonioprism can be used to observe the bright spots that indicate the location of the trocar and composite microcannula.

[0059] An example of a preferred entry point 606 for the trocar 200 through the sclera is shown in FIG. 21 on a tangent 604 to Schlemm's canal. The entry point 606 of the trocar 200 into the sclera 1002 can be offset from the limbus on the tangent 604 by a predetermined distance. The offset distance can be selected such that when the trocar is inserted at the preferred entry point 606 with the trocar shaft 206 parallel to the tangent, the trocar will enter the interior of Schlemm's canal. As described in more detail below in connection with FIGS. 26-29, a trocar entry point marking device may be used to mark the preferred entry point 606 and the direction of advancement of the trocar along the tangent 604 on the surface of the eye.

[0060] The actuator 424 on the exemplary positioner 400 is shown in Figure 21 at the proximal end of its range of motion. As the actuator is moved distally from the position in Figure 21 to the position shown in Figure 22, the microcannula displacement mechanism 425, which may comprise the actuator block 426 and hollow sleeve 433 illustrated in the positioner embodiment 400 of Figure 20, causes the composite microcannula to extend from the distal end of the trocar. Displacement distance 630 in Figure 22 corresponds to the length of the portion of the composite microcannula that extends from the distal end of the trocar due to movement of the actuator 424.

[0061] In the example of FIG. 22, the composite microcannula segment extending from the distal end 202 of the trocar 200 follows a circumferential path of Schlemm's canal 1010 in a counterclockwise direction 611 from the trocar entry point 606. Light 614 emitted from the distal end of the composite microcannula 300 may be visible through the sclera as a small spot of light that pinpoints the location of the composite microcannula's distal end. Alternatively, the positioner 400 can be reoriented so that the composite microcannula follows Schlemm's canal in a clockwise direction. If the composite microcannula deviates from the preferred path, for example by leaving Schlemm's canal and entering the collecting canal, the re-pathing will be immediately evident by the illuminated distal tip of the microcannula.

[0062] The positioner 400 can be maintained stationary relative to the eye 1000 while the composite microcannula moves through Schlemm's canal or other portions of the eye. The positioner 400 can hold the composite microcannula stationary relative to the eye, for example, while a deliverable is delivered through the composite microcannula to a target site within the eye. Although the trocar examples in Figures 19-22 do not include a tab, these examples also apply to trocars that have a tab. The tab can be used to secure the positioner, for example, by fastening the tab to the patient's skin with adhesive tape or temporary sutures.

[0063] Some embodiments of the trocar are configured to accommodate two light guides. One of the light guides can be located within the compound microcannula, as previously described. The second light guide may be located within another compound microcannula or independent of the compound microcannula. Examples of trocars suitable for two light guides are shown in FIGS. 23 and 24. In the example of FIG. 23, a compound microcannula 300 is shown with its distal end 308 extending from the distal end 202 of the trocar 200 with light 614 emitted from the light guide within the compound microcannula. Additionally, an optional second light guide 412 is disposed within the lumen of the trocar 200 with the distal end 413 of the second light guide 412 remaining within the trocar with light 612 emitting from the distal end of the trocar. As suggested in FIG. 24, the two light guides may be optionally and selectively located within the trocar. It is possible to illuminate only the distal end 202 of the curl 200, only the distal end 326 of the composite microcannula, or both, either sequentially or simultaneously. The emitted light (612, 614) can optionally have a wavelength and / or intensity that is invisible to the unaided human eye.

[0064] An optional camera 616 may be provided to image the light (612, 614) emitted from the trocar and / or microcannula and transmitted through the eye tissue. The position of the composite microcannula and trocar may be viewed in an image from the camera 616 displayed on a computer monitor, a smart phone screen, and / or an instrument screen. In some microsurgical instrument embodiments 100, the composite microcannula 300 and the second light guide 412 may both receive light from the same light source. The composite microcannula may be advanced until it reaches a target site 1014, for example, an area where an obstruction or stenosis is to be removed or an area that will receive a product delivered through the composite microcannula.

[0065] FIG. 25 shows an example of a delivery object 620 carried in a cavity 303 in a flexible hollow tube 302 of a composite microcannula 300. The delivery object can follow a fluid path 324 in the composite microcannula. Thus, the composite microcannula can be used to precisely place the delivery object in a target site in the eye. The delivery object 620 can be a solid object 624, a fluid 622, such as a fluid consisting of gas and / or liquid, or both a solid object and a fluid. Optionally, a fluid can be used to carry the solid object 624. Alternatively, a long solid delivery object can be pushed into the proximal end of the composite microcannula until the long solid delivery object extends from the distal end of the composite microcannula. In the example of the composite microcannula 300 of FIG. 25, a light guide 304 is provided in the flexible hollow tube. Other embodiments of the composite microcannula 300 disclosed herein can also be used to carry the delivery object 620.

[0066] 26, 27, and 28 show an example of a trocar entry point marking instrument 800, also referred to as a marking jig 800. The marking instrument can be used to form a pattern of tangential lines on the sclera of the eye. The pattern of lines indicates at least one (optionally more than one) preferred trocar entry point and a preferred trocar insertion direction for guiding the trocar 200 through the sclera and into the internal fluid pathway in Schlemm's canal. The marking instrument 800 includes at least one pair of marking pads 810, 812. Each marking pad 810, 812 is preferably positioned to form a tangential line to Schlemm's canal when the edge 808 of the aiming hole through the hub 806 is concentric with the pupil of the eye. When the contact surface 814 of each marking pad 810, 812 contacts the surface of the eye, the dye applied to the contact surface can be transferred to the sclera 1002 as intersecting line segments.

[0067] The two marking pads 810, 812 in each pair are angled relative to one another such that the intersection of the two line segments marked on the eye represents the location of the preferred trocar entry point 606. The intersection of the two line segments is preferably spaced from the limbus 1008 by a predetermined separation distance 826 measured along a radial direction originating from the center 1018 of the pupil. The limbus 1008 indicates the location of the underlying Schlemm's canal 1010 with sufficient accuracy for the purpose of the markings made by the two pads 810, 812 to accurately represent the insertion location and orientation of the distal end of the trocar for entry into Schlemm's canal. The predetermined separation distance may be determined based on the selected length of each line segment marked on the eye and the number of individual trocar entry points 606 marked on the eye.

[0068] The pair of pads 810, 812 may be coupled to a central hub 806 to which a handle 802 may be attached. The pads 810, 812 may be attached to the hub. The radial arms 804 may be directly connected or may be connected to the hub by intervening radial arms 804. The example trocar entry point marking instrument 800 of FIG. 26 includes a hub 806 having seven radial arms 804. A first marking pad 810 and a second marking pad 812 disposed at an angle to the first marking pad are connected to each radial arm 804. Alternate embodiments of the marking jig 800 may include a different number of radial arms and marking pads than those shown.

[0069] Figure 29 shows an example of a trocar entry point marking made on the outer surface of the eye by the marking instrument 800 of Figures 26-28. In the example of Figure 29, the iris 1006 appears as the shaded area between the edge of the pupil 1016 and the limbus 1008, and Schlemm's canal 1010 is located near the limbus. In Figure 29, the limbus 1008, Schlemm's canal 1010, and the edge of the pupil 1016 are represented by dashed lines to distinguish them from the markings made by the instrument 800. The sclera 1002 appears in Figure 29 as the area outside the perimeter of the limbus 1008.

[0070] Each pair of marking pads 810, 812 prints a corresponding pair of line segments 818, 820 that are tangent to Schlemm's canal 1010. Each pair of line segments 818, 820 intersect at an intersection 822 that corresponds to a trocar entry point 606 on the sclera. One or more entry points 606 can be marked to provide a selection of trocar entry points to reach a target site within the eye. Each intersection 822 is radially spaced a predetermined separation distance 826 from the limbus 1008. Each intersection 822 may be marked with a dot or other marking to improve visibility of the location of the trocar entry point 606.

[0071] After the trocar entry point marking tool 800 is used to transfer the intersecting line segment pattern of the example of FIG. 29 to the surface of the eye, one of the intersection points 822 can be selected for insertion of the trocar into the sclera. The distal end 210 of the trocar 200 is preferably placed directly against the intersection point 822 on the sclera. The shaft 206 of the trocar is preferably positioned parallel to one of the line segments 818, 820, and the trocar is advanced parallel to the line segment from the intersection point 822 toward the limbus 1008, continuing its advancement motion until the illuminated distal end 220 of the trocar is observed to have entered Schlemm's canal 1010. After the trocar has entered Schlemm's canal, the composite microcannula 300 can be extended from the end of the trocar as described in connection with the examples of FIGS. 21 and 22.

[0072] 30 shows examples of steps included in a method embodiment. A method in accordance with embodiment 700 may include one or more of the following steps, in any combination:

[0073] In step 702, the distal end of the composite microcannula is placed within the lumen of the trocar.

[0074] In step 704, an intraocular structure is selected to receive the trocar. Schlemm's canal, collecting ducts, and blood vessels are examples of structures that may be selected, although it is understood that embodiments of the microsurgical instrument 100 may be used to introduce composite microcannulas into other chambers, vessels, or channels in the eye or other organs.

[0075] Example embodiments of the method may further include:

[0076] In step 706, a trocar entry point is selected on the eye.

[0077] In optional step 708, the trocar entry point is marked using a marking jig, such as trocar entry point marking tool 800 in the example of FIG.

[0078] In step 710, the distal end of the composite microcannula is illuminated, thereby illuminating the distal end of the trocar.

[0079] In step 712, the trocar is positioned at the selected trocar entry point.

[0080] In step 714, the trocar is advanced from the selected trocar entry point until the illuminated distal end of the trocar is observed to have entered the selected structure within the eye.

[0081] In step 716, the illumination transitions from the distal end of the trocar to illuminating tissue outside the trocar by extending the composite microcannula from the distal end of the trocar toward a target site within the eye, including, but not limited to, chambers, vessels, ducts, or ducts blocked by occlusive material, and narrowed or constricted spaces to be expanded or opened.

[0082] Example method embodiments may optionally include one or more of the following.

[0083] · Holding the distal end of the composite microcannula stationary relative to the trocar.

[0084] Select Schlemm's canal as the structure into which the illuminated distal end of the trocar will enter.

[0085] From the selected trocar entry point, advance the trocar tangent to Schlemm's canal.

[0086] Mark the trocar entry point at the intersection of two lines, each tangent to Schlemm's canal.

[0087] Position the two tangents so that they intersect at a suitable distance from the edge of the eye.

[0088] Center the marking instrument above the pupil of the eye and mark the two tangent lines on the surface of the eye by pressing the marking instrument against the eye.

[0089] Mark more than one trocar entry point each time the marking instrument is pressed against the eye.

[0090] · Illuminating the distal end of the trocar using a separate light guide.

[0091] Inserting the delivery material into the composite microcannula and delivering the delivery material to the target site.

[0092] Illuminating the distal end of the trocar with electromagnetic radiation having a wavelength invisible to the naked human eye and observing the distal end of the trocar with a camera sensitive to that electromagnetic radiation.

[0093] Withdrawing the composite microcannula from within the trocar while maintaining the trocar at the trocar entry point.

[0094] Inserting the delivery material into the composite microcannula.

[0095] -Transporting the delivery material through the composite microcannula to the target site.

[0096] Retraction of the composite microcannula, leaving the deliverable at the target site.

[0097] · Maintaining the trocar stationary relative to the eye after the distal end of the trocar has entered the selected structure within the eye.

[0098] 34, 35, and 36 show another example of a microsurgical instrument including a positioner configured to extend and retract a composite microcannula within a trocar lumen. The positioner 400 is configured to mount a trocar 200 to a distal end 418 of a handpiece 420. A composite microcannula 300 passes through the lumen of the trocar 200 and through the handpiece 420 and is coupled to an insert 488 that slidably engages the handpiece 420. As will be described in more detail below, sliding an actuator 424 a selected distance 484 within a slot 428 in the handpiece 420 displaces the composite microcannula relative to the end of the trocar's rigid hollow shaft 206 a distance 486 equal to twice the actuator displacement distance 484. The trocar 200 and composite microcannula 300 may be provided separately from the positioner 400 and may be removable for replacement if the trocar or microcannula becomes damaged, contaminated, or otherwise unusable for a particular procedure.

[0099] Some internal features of the positioner 400 illustrated in Figure 34 are shown in two cross-sectional views in Figure 36. Cross-section HH in Figure 36 shows the actuator 424 retracted toward the proximal end 416 of the handpiece 420. Cross-section JJ shows the actuator advanced toward the distal end 418 of the handpiece 420. These two views of the handpiece 420 include references to each other in Figure 36 so that the positions of the internal components can be accurately compared between the cross-sectional views.

[0100] The insert 488 slidably engages an inner surface of a cavity formed inside the hand piece 420. The actuator 424 moves along one or more guide ridges 430. A U-shaped hollow tube 492 attached to the actuator 424 moves with the actuator. An insert displacement wire 490 slidably passes through the lumen of the U-shaped hollow tube 492. One end of the insert displacement wire 490 is fixed to the insert 488. The opposite end of the insert displacement wire 490 is fixed to an anchor post 494 that is rigidly attached to or formed as an integral part of the hand piece 420. The insert displacement wire 490 is preferably flexible enough to easily slide within the bent portion of the U-shaped hollow tube 492, while at the same time being stiff enough to push the insert 488 distally (i.e., away from the trocar 200) as the actuator is moved distally.

[0101] With one end of the insert displacement wire 490 secured to the handpiece 420 at an anchor post 494 and the other end secured to the insert 488, the actuator 424 sliding along the handpiece a distance "d" 484 displaces the U-shaped hollow tube 492 the same distance "d" and displaces the insert 488 twice as far (2 x d). This double displacement is shown in the figure as a relative displacement 486 of the insert between cross sections HH and KK. When the actuator slides along the handpiece The composite microcannula 300 is coupled to the insert 488 sufficiently strongly to maintain the composite microcannula stationary relative to the insert as it is moved relative to the base. As the insert moves twice the actuator displacement distance 484, the composite microcannula also moves twice the actuator displacement distance 484. Moving the actuator proximally a distance "d" 484 extends the composite microcannula a distance "2 x d" from the trocar. Moving the actuator distally a distance "d" 484 retracts the composite microcannula a distance "2 x d".

[0102] The composite microcannula 300 may be threaded within a hollow sleeve having a fixed segment 436 that is attached to or formed as an integral part of the rigid hollow shaft 206 of the trocar 200. A movable segment 434 of the hollow sleeve slidably engages the fixed segment 436 at one end and is attached to the insert 488 at the other end. The hollow sleeve limits transverse deflection of the composite microcannula upon advancement and retraction of the actuator, allowing the composite microcannula to be extended and retracted within the handpiece without twisting or significantly bending.

[0103] 36, the composite microcannula 300 may extend from the proximal end 416 of the positioner 400 and the insert 488. The proximal extension of the composite microcannula may be configured to accommodate solid and / or liquid deliverables, surgical instruments, and one or more optical fibers as previously described.

[0104] Unless expressly stated otherwise in this specification, general terms have their ordinary meaning in the context in which each appears and general terms in the art have their ordinary meaning.

Claims

1. A handpiece, an actuator slidably coupled to the handpiece; an insert slidably coupled to the handpiece; a hollow tube attached to the actuator; a wire threaded within the hollow tube, a first end of the wire attached to the handpiece and a second end of the wire attached to the insert; and a trocar coupled to the handpiece; a composite microcannula coupled to the insert through a lumen of the trocar; An apparatus comprising:

2. the trocar having a rigid hollow shaft; a hollow sleeve having a movable segment slidably connected to the rigid hollow shaft; the movable segment is attached to the insert and the composite microcannula is configured to pass through the movable segment; 2. The apparatus of claim 1.

3. The apparatus of claim 1 , wherein the hollow tube is a U-shaped hollow tube.

4. the trocar comprises a rigid shaft having a proximal end and a distal end, the rigid shaft defining a lumen extending from the proximal end to the distal end, the distal end being shaped for penetration of tissue; The composite microcannula is disposed within the lumen, the composite microcannula comprising: a flexible hollow tube having an outer diameter smaller than an inner diameter of the lumen; a light guide coupled to the flexible hollow tube.

2. The apparatus of claim 1.

5. The apparatus of claim 4 , further comprising a light source positioned to direct light into the light guide to illuminate a distal end of the light guide.

6. The apparatus of claim 4 , further comprising a second light guide positioned to illuminate the distal end of the trocar.

7. The device of claim 4 , wherein the proximal end of the composite microcannula is in fluid communication with the distal end of the composite microcannula.

8. The device of claim 4 , wherein the composite microcannula is configured to deliver a solid deliverable into the flexible hollow tube.

9. The apparatus of claim 4 , wherein the light guide comprises layers of material concentrically disposed around a cavity within the flexible hollow tube.

10. The apparatus of claim 4 , further comprising a positioner configured to hold the composite microcannula.

11. The apparatus of claim 10 , wherein the positioner is configured to displace the compound microcannula relative to the trocar.

12. The apparatus of claim 10 , wherein the positioner is configured to hold the composite microcannula stationary relative to the trocar.

13. The device of claim 10, further comprising a hollow sleeve, the composite microcannula passing through the hollow sleeve.

14. The device of claim 13 , wherein the length of the hollow sleeve varies with displacement of the composite microcannula relative to the trocar.

15. The apparatus of claim 10 , wherein the composite microcannula is fixed to the positioner.

16. The device of claim 10 , wherein the positioner is configured to slide into contact with the composite microcannula.

17. The trocar further comprises: a rigid hollow shaft having a distal end configured for tissue penetration, the rigid hollow shaft having a lumen extending from the distal end to a proximal end of the shaft; a transition structure attached to the proximal end, the transition structure having an opening for receiving the composite microcannula within the lumen of the rigid hollow shaft; a smoothed distal end of the lumen of the rigid hollow shaft; Equipped with The apparatus of claim 10 , wherein the positioner comprises a light source positioned to illuminate the distal end.

18. The device of claim 17 , wherein the trocar further comprises a tab extending outwardly from the transition structure.

Images