CA1233718A

CA1233718A - Ophthalmic perforating instrument

Info

Publication number: CA1233718A
Application number: CA000445659A
Authority: CA
Inventors: Maxwell A. Helfgott; Gerald N. Helfgott
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-02-08
Filing date: 1984-01-19
Publication date: 1988-03-08
Also published as: US4530359A

Abstract

TITLE OF THE INVENTION:
OPHTHALMIC PERFORATING INSTRUMENT

ABSTRACT OF THE DISCLOSURE:
A surgical instrument for ophthalmic use comprises a rigid elongated outer tubular member which terminates in a closed distal end immediately adjoining a distal side opening. A flexible elongated wire is arranged within the outer tubular member and extends in a direction generally parallel to the longitudinal axis of the outer tubular member. The wire is axially movable within the outer tubular member and has a shape distal end which is positioned in proximity to the distal side opening. The closed distal end of the outer tubular member is provided with an interior curvature which functions as a deflecting member to deflect the distal end of the wire to that the wire projects through the distal side opening at an angle relative to the longitudinal axis of the outer tubular member when the wire is moved axially toward the distal end of the outer tubular member. The wire may be supported by an inner tubular member which is slidable within the outer tubular member and which also functions to conduct an infusion fluid to the instrument tip. Modifications to the basic embodiment include the use of a fixed length of small diameter inner guide tubing as the deflecting member to guide the distal portion of the wire in the direction of the distal side opening in the outer tubular member, and the formation of the wire as a ribbon-like extension of the slidable inner tubular member which serves as the infusion conduit. A surgical method employing the perforating instrument is also disclosed.

Description

~337~L~

E3ACKGROUND O~ THE INVENTION:

Field of the Invention The present invention relates generally to ~;urgicæl instruments and methods, and is particulfirly concerned with an ophthalmic instrument and S method in which a flexible wire is used to make a line of perforations in the anterior lens capsule of the eye.

Description of the Prior Art Endophthalmic surgery, or surgery on an intact ~nd normally pressurized eye, represents an important and relatively recent development in the Pield of ophthalmology. In th;s technique, the existing optical pathways of the pressurized ocular globe are utilized for visu~lization during delicate intraocular manipula~ions. Maintenance of positive intraocular pressure tends to preserve and ~;tabilize the spati~
relationships among the various intraocular tissues.
The archetypal endophthalmic procedure is the cataract aspiration technique of extracaysular cataract surgery~ described by Scheie, ~Am. J.
~; ~ 50:1048 (1960), wherein an instrument is passed through a small incision at the margin of the cornea into the anterior aqueous chamber of ~ ~ the eye to incise the anterior capsular membrane of the lens. The aqueous, which~ leaks out during this manipulation, is replaced by ~
gravity-fed infusion of physiologic saline through a cannul~ inserted into the anterior chamber through a second small inc;sion. A blunt needle is then inserted through the first incision into the lens~ whereupon gentle suction ~spirates the soft lens substance lea~ng the posterior capsular

2 5 membrane in place . Whatever volume is removed or leak~ from the two small incision6 i6 replaced by the continuous gravity feed of saline.
Absent any seepage or applied suction, the pressure in the ey~ sta~ilizes . ,.~
Il ~ I

~33~8 at a point determined by the physical elevation of the Ealine column above the Ievel of the eye. At the end of the procedure, ~11 tubes are withdrawn and the incisions are sutured.
The crystalline lens of the eye is a viscid, cellular, biconvex structure enclosed in a transparent, elastic membrane Xnown as the capsule. The lens adjoins the posterior iris and posterior chamber anteriorly, the zonular ligaments ~nd ciliary body equatoIrially, and the vitreous body posteriorly. When disease or degeneration degrades the optic~ quality of the crystalline lens, the resulting opacity is called a 1 Q cataract . Modern cataract surgery involves removal of either the entire lens and capsule, which is 3cnown as intracapsular cataract extraction (ICCE), or piecemeal removal of the lens substance after opening or excising the cspsule, which is known as extracapsular cataract extraction (ECCE). Both techniques have undergone steady refinement oYer the past century in order to reduce the risks and improve the results of cataract surgery.
Modern endophthalmic ECCE requires a controlled, predictab]e opening in the anterior capsule. Many techniques and instruments have ~een proposed w~th which to accomplish this.
The earliest method of opening the anterior capsule was needling or incising the membrane with multiple, slashing incisions made with a knife needle or a scythe-like instrument called a cys10tome. Another early teehnique involved grasping the anterior capsule with tooth forceps and tearing off a piece of the capsule. C)f course, because of the large size of 2~ the instrument, it was necessary to open the eye in order to maneuver the instrument onto the surface of the capsule.
The precursor of modern capsulectomy techniques is the "Christmas tree" or dull cystotome method as ~populari~ecl by Kelman. The ante~ior capsule is cngaged opposite the ent y site and is torn in one movement __ o ~3~7~

toward the surgeon, creating a triangular flap which is pulled out of the eye and then excised. As originally described by Kelman, other small tears could be added along the 6ides of the triangle to enlarge the opening .
Renewed interest in ECCE in recent years has led to many alternative capsulectomy methods. The common theme has been to increase the control of the excision with less emphasis on tearing and ripping. Also, it is well recognized that endosurgical capsulectomy is particularly desirable in order to visualize the capsule and avoid damage to adjacent intraocular tissues.
One technique suggested the use of a circul~r resistance wire encased, except for its concave posterior surface, in an insulating disc which would be apposed to the anterior capsule with mild suction. The wire would be brieIly heated to cut the membrane. This technique has not become commercially available.
The most widely used capsulectomy technique at the present time is a modification of the '~ Ch~stmas tree" method, known as the "can opener"
method. The instrument used is usually a 25 to 30-g~uge hypodermic needle with its bevel bent at 90 degrees to the shaft. This is placed in the eye through a small incision and used to make small triangular tears, which are typically confluent, along the desired line of eXCiSiOII. Although in skilled hands this is an extremely effective method, it is difficult to master for the occasional ECCE surgeon. Another drawback is that the pupil must be widely dilated, since the instrument is controDed by direct visualization. This technique is also very ~i~ficult when the capsule is very thick and Ic~ose, as in traumatic catarac~, or when the capsule is thin and tense, as in a mature or ripe cataract.
There has been at least one attempt to design a powered surgical instrument capable of opening the aTIterior lens capsule of the eye prior to ~ataract surgery. ~n U~S. Pat. No. 3~80~,0g3 to Abraham, a hand-held ~ 7~

surgical înstrument is described which includes a rod or probe terminating in ~ sm11 globular tip. An electromagnetic vibrating mechanism in the hand~e portion of the instrument imparts a limited transverse arcuate or swirlging motion to the rod and tip at a controllable rate up to about 100 S cycles per second. The globular tip may be provided with a pointed or knife edged projection in order to form multiple smPll incisions in the anteFior capsule ~f the lens ~s the rod or probe vibrates. With different types of smooth, abrasive or knife-edged globular tips, the instrument can also be used to carry out other types of intraocular surgical procedures, ¦ such as cataract disintegr~tion or remov~l of the posterior lens capsule.
The difficulty with this instrument, st least inss~far as its applicatic>n to removal of the anterior lens capsule is concerned, is that the vibration of the globular tip occurs in a direction transverse to the direction of the pointed or knife-edged projection. As a result, the incisions in the anterior lens capsule are actually small rips or tears, rather than discrete perforations. Al~o, the exposed vibrating tip of this instrument may pose a danger to neighboring intraocular tissues, particularly when it is desired to incise the anterior lens capsule in the marginal region beneath the dilated iris.
More recently, pulsed infrared and near-infrared lasers have been demonstrated to be capable of creating multiple fine perforations of the anterior capsule prior to surgery. This development has been reported by I~. Aron-Rosa, Am. Intra-Ocular Implant Soc. J. 7:332 (1981). The laser method iB advantageous because it requires no direct instrument contact 2 5 with the lens capsule, and hence it is æubstantially non-invasive .
Rowever, this method requires a clear optical path to the capsule sur~ce and is therefore incapable of forming the desired line of perIorations ~ong the margin~l portion of the anterior capsule which is obscured by the dilated iris. Another drawbaclc of this technique is that the necessary 1233~

laser equipment is extremely large and extraordinarily expensive, and uccomplishes essentiRlly the same result that can b9 obtained by using a disposable hypodermic needle.
In summary, the evolution of eye surgery in general and E(: CE: ~n particular is characterized by emphasis on precise place,nent of all tissue handling instrwrJents, controlled incisions rather than unpredictable ripping or tearing, and the use of endosurgic~l techniques allowing microscopic visualiz~tion using the intact optical pathways of the eye.

SUMMARY O~ THE INVENTION:
_ .
In accordance with the present invention, the foregoing disad~rantage6 ~nd limitations of the prior art are substantially avoided by providing an ophthalmic surgical instrument which complqses ~ rigid elongated outer tubular member lerminating in a closed dist~l end immediately adjoining a distal side opening. A flexible elongated wire is arr~nged ~ithin the outer tubular member and extends in a direction generally par~llel to the ]ongitudin~l axis of the outer tubular member. The wire is axially movable within the outer tubular member and has a sharp distal end which is positioncd in proximity to the distal side opening formed in the outer tubulnr member. Deflecting means within the closed distal end of the 2 0 outer tubular member is effective to deflect the distal end s)f the wire 80 that the wire projects through the distal side opening at an angle relative to the longitudinal axis of the outer tubular member in response to axi~
movement of the wire toward the distal end of the outer tubular member.
The deflecting means may comprise a distal end wall on the outer tubular member which ha6 a curved interior surface, or e rigid small diameter inner guide tube, preferably curved, which is affixed within the outer tubular member in surrounding relationship with the distal end sf the wire. In a preferred embodiment of the invention, the wire is supported ~ 3~

by an inner tubular nnember which is coaxially and slidably arr~nged within the outer tubular member, with the inner tubular member serving as an infusion line for conducting fluids to the instrument tip. In this embodiment, the wire may comprise a ribbon-like extension of the inner tubular member itself, although it is also possible to employ a separate wire which is attached by any suitable method to the inner tubular member .
In operation, the instrument is inserted through a limbal incis;on made at the margin of the cornea. The tip of the instrument is positioned so that the distal side opening in the outer tubular member faces the anterior lens capsule at the point where the desired perforatiolls are to be made. The wire is then reciprocated back ~nd forth in an axial direction within the outer tubular member, causing the sharpened distal end of the wire to repeatedly project from the distal side opening ~nd to perforate the capsular membrane . After each perforation is made, the ins trument tip may be moved slightly to create a further perforation located very close to the preceding per~ration. This process may be repeated until a conffnuous line of perforations has been defined around the margin of the capsular membrane. The finished line of perforations defines a weakened 2 0 tear or score line which will allow the central portion of the anterior capsule to be pulled back or removed in ~>rder to provide access to the lens material for cataract removal or the like. Saline infuæion may be introduced through the instrument tip, preferably by means o~ the slidable inner tubular member which carries the flexible wire, in order to replace any lost aqueous and prevent collapse of the cornea.
The present invention provides ~ number of important advantages over previously used techniques for opening ~he anterior lens capsule; In the ~irst place, the sharpened tip of the wire which projects from the distal side opening of the instrumen~ ~orms a clean per~oration ~n the ~2;~3~

capsular membrane, without ~n~ si,g~3j~fio~llt amount sf ripping or tearing.
Since the perforations are no~ - confluent, unlike the triangular inci6ions resulting from the prior ~t `~'can opener't method, the tautness of the capsular membrane i6 preserved as the perforations ~re formed. Both of these ~actors, th~t is, the lack of ripping or tearing in the perforations and the preservation of the tautness of the capsular membrane, are helpful in providing a controlled, predictable opening in the anterior capsule. In ~ddition, 6ince there is no moYement at the instrument tip other th~n the protrusion of the wire through the distal æide opening, the instrument can be u6ed without the risk t~f damage to tissues adjoining the anterior capsule. Finally, unlike the laser method, there i~ no requirement for a clear optical path to the area of the anterior c~psule where the perforations are to be made. This permit6 the line of perforations to be defined ~round the marginal portion of the anterior capsule which is obscured by the dilated iris, and hence allows a relatively large c>pening to be made in the anterior capsule.
The present invention also embraces a Burgical method ~r opening an intraocular lens c~psule which can be carried out u~ing the instrument described above. The method involves the steps of repeatedly penetrating 2 0 the lens capsule with the sharpened tip of a flexible wire or ribbon without appreciable ripping or te~ring of the capsule to form a line of closely spaced, non-confluent perforationfi in the lens capsule, and then pu~ling away or removing a portion of the lens capsule along the line of perforations. The line of perforation~ may extend completely around the surface nf the lens capsule, as for example where it is desired to completely remove or excise ~ portion of the lens capsule. Alternstively, the line of perforations may extend only partially ~round the surface of the lens capsule, as for example where it i~ desired to create ~ capsule flap which can be pulled away from the adjoining portion of the lens ~:3;3i~

capsule. In order to create the largest possible opening in the lens capsule, the line OI perforations preferably extends at le~6t partially beneath the i:~s of the eye. A saline infusion i~ preferably conducted into the eye during the forming of the perforations in order to maintain positive intr~ocular pressure. The method is especially useful for opening the anterior lens capsule of the eye, but can also be used to remove the posterior lens capsule if desired.

BRIEF DESCRIPTlON OF THE DRAWINGS-_ .
The various objects, adv~ntages and novel features OI the present inventiorl will be more readily apprehended from the following detailed description when read in connection ~ith the appended drawings in which:
Fig. 1 is a side sectional view of powered surgical handpiece which is fftted with one embodiment of the perforating instrument of the present invention;
Fig. 2 is an enlarged side sectional view of the perfor~ting instrument, with portions of the inner ~Lnd outer tubular members omitted ~or clarity;
Fig. 3 is an enlarged bottom view of the perforating in~trument, ~lso ~: ~ with portions of the inner and outer tubular members omitted;
~ Fig. ~ is an enlarged side sectional view of the distal portion of aperforating instrument constructed in accordance with a second embodiment of the present invention;
Fig. 5 is 8 cross-section~l view taken along the line 5-5 in ~ig. 4;
Fig~ 6 is an enl~rged sectional view of the distal portion of a 1 perforating instrument constructed in accordance with a third embodiment of the present invention;
Fig. 7 i8 a bottom view of the distal instrument portion illustrated in ig. 6;

3711~

., Fig. 3 i~ a c~os~-~ectiona~ view taken 01~ng the line 8-8 in Eig. 6;
Fig. 9 i~ a per~pective view of the inner tubular member used in the embodiment of Figs. 6-8, illustr~ting the Iqbbon-like extension of the inner tubul~r member;
Fig. 10 i~ ~ sectional view of the anterior part of the human eye illustrsting the insertion OI the perfor~tLng instrument into the anterior chamber through ~n incision made at the margin of the cornea; and Fig. 11 is a~ elevationsl view iLlustrating the manner in which the perforating ~nstrument of the present invention may be u~ed to define a ` line of perfor~tions around the marg~n of the snter~or lens capsule of the eye in the are~ beneath the dilated iris.
Throughout the drawings, like reference numeral~ are used to iden~fy like part~.

. DETAILED DESCRIPTION ~ THE PREFERRED EMBODIMENTS:
lS Fig. 1 is ~ 6ide ~ectionsl view of a powered ~urgical handpiece lû
which may be fitted with the perf~rating instrument of the present invention. The handpiece 10 i~ de~cribed in detail in the ~pplicant~' earlier U.S. Patent No. ~,314,~60.

2 0 The handpie;?e 10 will be seen to include a cylindrical housing compFisiJIg an anterior cylindrical section 12, a central cylindrical 6ection 14, and ~ rear cylindrical ~ection 16. l'he rear part ~ the s~entral housing section 14 includes an externally threaded portion 36 w}lich en~ages a corre~ponding internally threaded portion 38 of the re~r housin~
secffon 16. In ~ ~imilar manner, the forward end 52 of the central housing section 14 is externally threaded 3n order to engage a corresponding internally threaded porUon ~0 of the anteriur housing ~ection 12. The central 6ection 14 and re~r ~e~tion 16 to~ether comprise 1.;~33718 whst may be referred to as the postelior section of the handpiece or, in ronnecffon with the component6 they receive, as the main body of the handpiece.
The anterior &ection 12 of the handpiece is lStted with a projecting tubular 6urgical instrument 15 which includes an elongated outer tubular member 18 and an inner tubular member 48. The inner tu~ular member 48 is coaxiAlly and slidably received within the outer tubular member 18 for axial reciprocntion therein. A ~lexible wire 82 is carried by the inner tubular member 48 and extends generally parallel to the longitudinal axis of the outer tubular member 18. The distal end of the wire 82 is positioned in proximity to a distal side vpening 84 formed in the outer tubular member 18 and projects a ~hort distance through the opening 84 when the handpiece 10 is in operation. The structure and operation of the instrument 15, together with alternAtive embodiments thereof, is the ~ubject matter of the present invention and will be described in some detail hereinafter.
A ~lexible pneumatic supply line, not shown, is attached to the rear section 16 of the handpiece 10 and is connected at its opposite end to a suitable pneumatic power supply, also not shown, for proYiding 2 0 intermittent pulses of compressed air or other gas to a pneumatic sctuator 30 with~n the handpiece. The pneumatic actuator 30 imparts axial reciprocating motion to the inner tubular member 48 within the ~ixed outer tubular member 18, the latter being press-fitted into the anterior section 12 of the handpiece. A flexible tube 22 is connected at a point within the handpiece to the prox~mal end of the inner tubular member 48, as shown, and passes loosely out of the handpiece through an opening 24 formed in the cylindrical side surface of the handpiece. The inclined rear wall portion 70 of the opening~ 24 and the inclined guide sllrIace 68 formed on the closed end portion 66 of a coupling member 42 cooperate to assist the ,.

~2337~

flexible tube 22 in bending smoothly ~s it passes ou~ of the handpiece.
The flexible tube 22 will normally be used for conducting infu~ion fluids through the inner tubular member 48 when the projecting surgical instrumellt is of the type shown, although for other types of instrument6 the flexible tube 22 may be used to apply 6uction ~aspiration) to the inner tubular member. In this s~onnection, it should be noted that the anterior portion 12 of the handpiece is removable to permit the attachment of different types of surgical instruments, a capsbility which will become more apparent as the description proceeds.
With continued reference to Fig. 1, the coupled rear section 16 and central section 14 of the handpiece ht~using together define an internal cylindrical cavity 39 for receiving the pneumatic actuator 30. The rear section 16 ~f the housing is provided with internal threads 26 for making airtight engagement with a threaded fitting 28 formed on the rear part of the pneumatic actuator 30~ The pneumatic actuator 30 contains an internal piston and spring return Ior urging R pusher member 32 linearly ~r axially outward with respect to the cylindrical body portion 34 of the actuator in response to the intermittent pneumatic pressure pulses ~upplied through the fitting 28. An annular wall 40 located a short distance behind the 2 0 opening 24 in the central housing section 1~ defines the forward extent of the cavity 39 and provides a circular aperture through which the pusher member 32 passes. The conical tip of the pusher member 32 is received in a correspondingly shaped depression 58 ~ormed in one end of the coupling member 42.
The coupling member 42 is slidably received in a cylindrical cavity 41 located forward of the annular wall 4Q and servea to transmit the axial reciprocating motion of the pusher member 32 to a disk-shaped platform member 44. The platform member 44 is secured to the inner tubular member 48 of the surgical instrument ~t a point 60mewhat ahead of the :1~337~L8 proximal end of the inner tube 48, thereby insuring sufficient room for the attachment of ~he iEle~ible tube 22 to the inner tube 48. The platform member 44 is maintained in abutting contact with the ~orward part of the coupling member 42 by virtue of a return ~pring 54. The return spring 54 is con~ined within a narrow cylindrical cavity 62 formed within the anterior section 12 of the handpiece, and is maintained in a compressed condition between the platform member 44 and the forward interior wall 56 of the cavity 62.
In operation, the coupling member 92 provides ~n abutting mechanical connection between the reciprocating pusher member 32 of the pneumatic actuator 30 and the platform member 44 which is secured to the prox~mal end 46 of the inner tubular member 48. At the same time, the recesæed configuration of the coupling member 42 resulting from the open cavity 43 formed therein permits the flexible tube 22 to be connected to the proximal end 4l6 of the inner tubular member 48 as the latter reciprocates. Such reciprocation will occur when a positive pressure pulse is applied to the pneùmatic actuator 30, causing the pusher member 32 to move forward.
This forward motion is transmitted by the coupling member 42 to the platform member 44, which moves forwPrd to the limit of itæ travel as 2 0 de~med by the annlllar shoulder 60 . The forward motion of the platform member 44 causes an equal forward movement oiE the inner tubular member 48 and wire ~2 within the outer tubular member 18, which causes the distal tip of the wire to protrude from the opening 84 at the instrument tip.
This produces a tissue perforating action at the instrument tip as wi31 be 2 5 described hereinafter. When the pressure pulse terminates, the pusher member 32 retracts and the return sprin~ 54 causes the platform member 44 ~nd coupling member 42 to return to their rest positions. This motion retracts the inner tubular member 48 and wire ~ and completes the cyc]e OI operation. The platform member 4g is provided with a projecting key 78 : ;13-~2337~3 ¦ for engaging A corresponding longitudinal groove 80 formed on the interior ¦ surface of the anterior housing section 12. The purpose of thi~
¦ arrangement is to maintain the inner tubular member 48 in A ~Ixed ¦ rotational position with respect to the outer tubular member 18.
¦ The handpiece 10 of Fig. 1 allows interchangeability among di~ferent surgical instruments simply by uncoupling the anterior housing section 12 from the main body of the handpiece. This allows the removal of the inner ~nd outer tubular members 48, 18 and the wire ~2, which form the surgical instrument 15, together with the return spring 54, the plstform member 44, and the anterior housing section 12 which carries all of these components. Such removal is readily accomplished in view of the ~ct that there is no necessity for rigid mecha~ucal connection between the coupling member 42 and the platform member 44 when the handpiece is in its assembled condition, since the return spring 54 maintains these components in abutting contact with each other. When the ante~or housing section 12 is removed, the platform member 44 and the coupling member 42 are sep~rated, with the coupling member 42 remaining behind as part of the main body of the h~ndpiece. A new anterior housing section, carrying a different type of surgical instrument (or ~he same type of instrument in cases where the previous instrument has simply become worn~, as well ~s a new platform member and return spring, can now be Loupled to the main body of the handpiece. The necessity of threading the nexible tube 22 through the opening 24 in the side of the ~andpiece during the substitution of a new instrument can be avoided by extending the opening 2 5 24 to the forward edge of the central housing section 14 to ~orm an open-ended slot. When the anterior housing section 12 has been ~ttached, its rear edge closes o~f the open end of the slot to form the f~anctional equivalent of the opening 24.

~ ~33~

The surgical infitrument 15 i6 ~ .r~ in znore detail in the enlarged views of Figs. 2 and 3. The ~Istr~Jment 15 includes a rigid elong~ted outer tubular member 18, circul~ in cro6s-~ection, which terminates in ~ closed distsl end wall 86 immediately adjoining a distal ~ide opening 84. The distal end wall 86 is curved ~o provide an interior curvature within the distal end of the outer tu~bular member 18. A rigid inner tubular ~ember 98, also circular in cross-~ection, is coaxially snd slidably arranged within the outer tubular member 18 with its open distal end terminating ~ell behind the side opening 84 in the outer tubular member ~s sllown. The inner tubular member 48 carriee a flexible elongated wire 82 which is ~rranged within the outer tubular member 18 60 that the wire extends generally parallel to the longitudinal axis of the outer tllbular member. The wire 82 is provided with a sharpened distal tip 88 which is positioned in proximity to the distal side opening 89 formed in the outer tubular member 18. The fle~nble wire 82 is prefersbly pre-formed with its distal end portion 90 curved in the direction of 2he side opening 84, as shown. The proximal por~ion of the wire B2 runs par~llel to, and i6 in contact with, the interior side wall s~f the inner tubular member 48, and terminates in a D-shaped bend ~2 ~t the open 2 proxim~l end of the inner tubular member. The exposed portion of the wire 82 is secured to the proxim~l outside sUrIace of the inner tubular member 48 by any suitable method, such ~s so]dering or ~razing. This method of exteFior attachment leaves the interior of the inner tubular member 48 open and unobstructed ~o that it can be used ~or infusion purposes as will be described shortly.
The operati~n of the instrument 15 may be readily underst~d with reference to Fig. 2~ When the inner tubular member 48 is in the retracted pc~sition, shown in solid out1ines ~in Fig. 2, the sharpened dist~l tip 8B of the wîre 82 i8 positioned just înside the distal side opening B9 of the outer _ ,~

,,~

~3' ~

tubular member 18. These are the positions of the wire 82 ~nd inner tubular member ~8 when no pressure pulse is applied to the pneumatic actuator 30 of the handpiece 10 in Fig. 1. Du~ng an operating ~troXe, the application of ~ positive pressure pulse to the pneumatic actuator 30 causes the inner tubular member 48 to slide ~orward to the phantom line position shown in Fig. 2. When this occurs, the distal portion 90 of the wire 82 is brought into contaet with the elosed distal end 86 of the outer tubular rnember 18. The interior curvature of the distal end wall 8~
serves as a deflecting member and is ef~ective to deflect the distal end of the wire 82 so that the sharpened tip 88 projects through the distal ~ide opening 84 at an angle of about 90 relative lo the longitudinal axis of the outer tubular member 18. ~his is illustrated by the phantom line position of the wire 82 in F'ig. 2. The projecting tip 88 of the wire will serve to form a hole or perforation in the anterior lens capsule or other intraocular tissue positioned below the distal side opening 84. When the pressure pulse to the pneumatic actuator 30 of Fig. 1 terminates~ the inner tubular member 48 and the wire 82 return to the solid line positions shown in Fig.
1, and the sharpened tip 88 of the wire 82 is once again retracted to a position just inside the distal side opening 84 of the outer tubular member 18. This completes one cycle of operation. It should be noted that, since the movement of the sharpened tip 88 of the wire 82 occurs roug}lly in the direction in which the sharpened tip 88 initially points, the instrument 15 will be capable of ereating a disffnct hole or perforation in the intraocular tissue with a minimum of ripping or tearing.
2 5 A saline infusion is preferably conducted through the inner tubular member 48 by virtue oî the flexible infusion tube 22 of Fig. 1 in order to maintain n~rmal intraocular pressure when the instrument 15 is being use~d.
The saline infusion exits from the side opening 84 at the distal end of the outer tubular member 18, and it is for thi6 reas~n that the side opening ~4 , __ .

12;3371~
¦ is somewhat larger than necessary for free movement of the distal tip 88 ofthe wire 82. II desired, however, the opening 84 may be made smaller ¦ and one or more further openings may be provided in the anterior side ¦ wall of the outer tubular member 18 to assure an unobstructed outflow of ¦ the infusion fluid.
¦ In practice, the instrument 15 may be fabricated by using ¦ surgical-quality stainless steel hypodermic tubing for the inner and outer tubular members 48 and 18. The outer tubular member 18 may comprise 20-gauge T-304 stainless steel with a wall thickness of 0 . 006 inch. The inner tubular member 48 may comprise 23.5-gauge tubing of the same material with a 0 . 003-inch wall thickness . In order to provide the distal end 86 of the outer tubular member 18 with the configuration illustrated in Fig. 2, the outer tube 18 may be bent sharply through an angle of 90 and then cut at the point of bending to form the distal side opening 84.
The curved distal end surface 86 of the outer tubular member 18 corresponds to the outer radius of the bend prior to cutting. The natural tendency of the tubing to stretch at the outer radius of the bend accounts for the reduced thickness OI the distal end surface 86 where it adjoins the side opening 84. The flexible wire 82 may be made of a single,~ inch diameter strnnd of stainless steel, beveled at its distal end to form the sharpened tip 88. The proximal end of the wire 82 is secured to the open proximal end of the inner tubular member 98 by soldering or brazing in the manner described previously. The distal portion 90 of the wire 82 is preferably curved through a gradual arc, as shown, so that the tip 88 of 2 5 the wire aligns with the distal side opening 84 of the outer tubular member 18. This tends to assist the curved distal end surface 86 of the outer tubular member 18 in deflecting the distal end of the uiire 82 so that it can project smoothly from the distal side opening 84 without becoming caught or lodged within the instrument tip. Also, the curvature at the distal end ~37~8 of the wire 82 ~orces the wire to project from the dist~l side opening 84 in a direction more nearly normal to the longitudinal axi6 s)f the outer tubular member 18 than wou]d otherwise lbe the case.
It should be underst~d that the ~oregoing dimensions and speci~ications, together with any dimensions Emd specificatione given hereinafter, are presented merely ~y way of examp]e and are not intended to limit the scope of the present invention in ~y way, except as defined in the appended cla~ms.
ldeally, it is desirable for the distul tip 88 of the wire 82 to emerge from the distul side opening 84 in the outer tubular member 18 in a direction very ne~rly normal to the longitudin~l axis of the outer tubular member. This will occur when the distal part of the wire 8~ deflects through an angle of 90 us it projects from the dist~l side opening 8~. It is also desirable thut the extension of the wire not be accompanied by ~ny sidewisemotion of the wire in a direction transver6e to the axis of the tip 88. When these eonditions are satisfied, perforation of the lens capsllle occurs at a highly predictable position beneath the distal ~ide opening 84, and there is a minimum of ripping or tearing since the sharpened tip B8 of the wire penetr~tes the ]ens capsule in a vertical or normal direction without sny sidewise displacement. The in6trllment 15 of Fig~. 1 and 2 uchie~es a roughly perpendiulc~r extension c>f the tip 8~ of the wire 82, ~t ]east when the amount of extension is small relative to the length of the curved distaI portion 90 of the wire. However, the downward extension c~f the tip 88 of the wire is accompanied by a significant fc>rwurd displacement 2 5 of the tip in the right-hand direction, as can be seen by comparing the ~olid line and phantom ~ine position~ of the wire in Fig. 2. Thi6 result6 ~rom the tendeney ~f the ~trai~ht portion of the wire behind the curved distal p~>rtion 9~ to sl~pe slightly downward as the wire i~ forced again~t the curved distal end 86 of the outer tubular member 18, wh;ch brings the 1~
,, ~ 7~L~

forward edge of the di~tal side opening 84 into contact with a point slightly higher on the curved distal end 90 of the wire.
Figs. ~ and 5 illustrate a modificf~tion of the surgicai instrument which is effective to avoid the problem referred to above. The surgical instrurnent 19 of Figs. 4 and 5 is in most respects the ~ame as the instrument 15 of Fig6. 2 and 3, except that the modified instrument 19 has been provided with a rigid length of sm~ll diameter inner guide tubing 94 affixed within the outer tubular member 18 near the distal end thereof.
The guide tube 94, which may be made from a length of 29-gauge stainleæ6 steel tubing, is open at both endæ and is affixed by welding or the like along the interior w~ll of the outer tubular member 18. The open distal end 96 of the guide tube 94 is positioned within the side opening 84 of the outer tubular member 18 and points in a directlon approximately normal to the long~tudinul axis of the outer tubular member 18. The guide tube 94 is curved len gthwi6e through an arc of about gO to match the curvature of the closed distal end 86 of the outer tubular member 18, and has its open proximal end 97 positioned in the interior of the outer tubular member 18 and po~nting in a direction approximRtely parallel to the longitud~nal axis of the outer tubular mem~er 18. The flexible wire 82 is 20: threaded through the guide tube 94 so that the la~ter completely surrounds the curved distal portion of the wire which terminates in the sharpened tip :: 8~. .
In the embodiment of Fige. 4 and 5, the deilection of the dist~l end of the wire 82 as it projects through the side opening 84 is caused by the curvature of the guide tube 94, ra~her ~han by the curvel:l interior surface of the distal end 86 of the outer tubular member 18. Since the path of the distal part of the wire i~ constrained to follow the contour of the guide tube ~4, the projection of the sharpene~ tip 88 of ~he wire from the distal side opening 84 OI the ~nstrument occurs in a direction very nearly normal .

~33~

to the longitudinal axis of the outer tubular member 18, as indicated by the dotted line position in Fig. 4. This i~ not accompanied by any appreciable forward movement of the wire in a direction transverse to the axis of the~ tip 88, since the upper proximal portion of the guide tube 9~
prevents ~y deviation of the straight proximal part vf the wire 82 from its hvrizontal path. This insures that the sharpened tip 88 of the wire will cleanly penetrate the anterior lens capsule in ~ vertical direction without any appreciable amount of transverse forward movement resulting in ripping or tearing.
In lF`ig8. 6-9, a further embodiment 21 of the invent;on is illustrated in whieh the ~eparate wire 82 of the preYioUS embodiments is replaced by ~
fle~ible ribbon-like extension 98 of the inner tubular member 48'. The configuration of the inner tubular member 48' and its ribbon extension 9~
can be seen most clearly in Fig. 9, which illustrates the distal portion of the inner tubular member 48' removed from the outer tubular member 18'.
The distal end 100 of the ribbon extension 98 is prefer~b]y curved lhrough an angle of about 90, as shown, snd the istal tip of the curYed portion 10~ is provided with a double bevel to ~orm a sharpened point 102. The outer tubular member 1~', visible in ~Sg~. 6-8, is circular in cross-section 2 0 and formed from a length of cylindrical tubing which terminates in a curved distal end wall 104 having essentially the same wall lhickness as the elongated portion OI the tube. The distal end wall 104 is essentially hemispherical and adjoins the distal side opening 106 in a manner such that the interior surace of the wall 104 merges smoothly with the ~rward edge of the side opening 106. Hypodermic tubing incvrporaffng the hemispheric~ end wall 104, which is referred to as a controlled ~losure, i~
cummercially available and can be adapted to the present invention simply by ~orming the di~tal side opening 106 through a porti~n of the hemispheric~l tip.

~:337~8 The operation of the instrument ~1 of Figs. 6-9 i6 ~ubstanti~lly the same as th~t of the previous embodiments, except that the ribbon extension 98 is ~omewhat stif~er and more resistant to crimping or buckling within the instrument than the wire 82 of the previous instruments. The stiffness of the ribbon extension 98 al80 reduces its tendency to de-riate or "wander" from side to side as it projects from the instrument tip, which can sometimes be a problem with the wire 82. Finally, the difficulties involved in attaching the wire 82 to the inner tubular member 18 in the previous embodiment6 are avoided since the ~qbbon extension 98 is an integral part of the inner tubular member 48'.
In operation, forward movement of the inner tubular member 48' to the phantom line position of Fig. 6 causes the distal end lûO of the Fibbon extension 98 to be urged into contact with the curved interior surface of the distal end 104 of the outer tubular member 18'. The inteFior cur~ature of the distal end w~ll 104 causes the sharpened tip lU2 of the ribbon extension to project from the distal side opening 106 {It an angle of :: about 90 with respect to the longitudinal axis of the ou~er tubular member 18'. This position of the tip 102 is illus~rated in phantom lines in Fig. 6.
As with the embodirDent of FYgs. 2 and 3, there is some tendency for the 20 ~: distal tip 102 of the ribbon extension 9~ to move forward when this~: ~ occurs, due to the downward sloping of the proximal part of the ribbon extension 98 which allows the forward edge of the distal side opening lû6 :: to engage a slightly higher point on the curve~ distal end 100 of the ribbons extension. This effect can be minimized by positioning a guide ~: 25: ~ block 108 within the interior of the outer tubular member 18' at ~ positîon immediately behind the distal side opening 106. As can be seen by comparing Figs. 6 and 8, the guide block 108 comprises a solid cylinder with a narrow Iongitudinal section removed g~ong one of its edges. The guide block 108 is made of metfll or plastic and i8 a~fixed to the interior ~ 3;~

side wall of the outer tubular member 18' in a manner ~uch that the upper plan~r region of the guide block faces the ribbon extension ~8, which runs along the upper side wall of the outer tubular member 18'. In this E~osition, the guide block 108 defines a narrow guide channel 112 for the ribbon extension 98 with respect to the upper side wall of the outer tubular member 18'. When the ribbon extension ~8 is moved forward by the inner tubular member 48', the forward edge 114 of the guide block 108 act~ QS a support ~or the distal portion 100 of the ribbon extension ~nd reduces the amount OI downward sloping which may occur in the proximal region of the ribbon extension ~8. As a result, the sharpened tip 102 of the ~ibbon extension project6 from the distal side opening 106 in a direction very nearly normal to the longitudinal axis of the outer tubular member 18, as indic~ted by the phan~om line position in Fig. 6, but does not move forward to any significant extent in the direction transverse to the axis of the tip 102. As pointed out earlier, this i~ helpful Ln producing clean perforation6 in the anterior lens capsule with a minimum of : ripping or tearing.
: ~ .As in the previous embodiment~, the inner tubular member 4BI of the perforating instrument 21 is preferably used to conduct ~a ~aline infusion ~0 through the instrument tip in order to maintain normal intraocular pressure :~ ~ during the surgical procedure. With the guide blocl~ 108 in place, it will be seen that the flow path which exists between:the open proxim~ end of the inner tubular member 48' and the distal side opening 106 in the outer tubular member 18' is substantially obstructed, except for the narrow guide ehannel 11~ through which the ribbon extension 98 passes. In order to insure an eîficient outflow of the infusion fluid from the instrument tip, a second side opening 110 is provided in the side w~ll of the outer tubul~r member 18'. The side opening lln occupies ~ position between the guide block 108 and the open distal end of the inner tubular member 48'.

_._ , ~3~

Fig6. 10 and 11 illustrste the manner in -~hich the instrument of the present invention may be used to f~cilit~te removal of a portion of the anterior lens capsule of the eye prior to catarflct ~urgery. The instrument 21 which is shown in Fig6. 10 and 11 corresponds to the embodiment of S Figs. 6 to 9, ~Ithough it should be understo~d that the instruments 15 and 19 Df ~gs. 2-3 and 4-5, respectively, would be employed in a similar manner. As can be ~een most clearly in ~5g. 10, the in6trument 21 is inserted through a limbal incision 11~ which i~ formed in the margirlal part of the cornea 116 st the point where the cornes joins the sclera 118. The instrument tip is maneuvered so thal the distal ~ide oper~ing 106 and the retracted tip lû2 of the ribbon extension ~ace the anterior capsule 122 of the lens body 123. The instrument tip is preferably positioned in the area behind the dilated iFiS 124, as shown, so that perforations can be made as close as possible to the margin of the anterior capsule 122.
With the in6trument 21 in position, the handpiece 10 of lF~g. I is operated to cause the sharpened tip 102 of the ribbon within the instrument to protrude from the distal side opening tO6. The handpiece 10 has been omitted from ~;`ig6. 10 and 11 for clarity. Each time that the sharpened tip 102 of the ribbon projects from the instrument tip, a perforation i6 made through the ~nterior capsule 122. The instrument i6 repositioned by the surgeon ~fter each perforatlon is made, so that a further perforation can be formed very close to the preceding one. By repeating this process many times, a continuous line of closely-spaced, non-conf~uent perforations 126 ean be formed around the margin of the anterior capsule 122 as illustrsted in ~g. 11. Since the perforations are non-confhlent, unh~e the trianglllar incisinns that are typically made ~nth the prior art "can opener" method, the tautness of the capsular membrane is preserved throughout the perforating step. Also, 6ince the perforations 12~ are made without ripping or tearing, the s;hape of the excision can be " ~

~2~37~

carefully controlled. The line of perforations 126 can be made in complete circle ~round the 6urface of the capsular membrane, as where it is desired to completely remove the central port of the anterior capsule.
Alternatively, the line of perforations can extend only part way around the ~urface of the ~nterior capsule to create a capsule flap. The flap is pulled away from the adjoining portion OI the lens capsule but remains partly attflched. The latter procedure will lbe followed, for example, in cases where it is desired to use the capsule flap to secure an ophthalmic lens implant after the surgery has been completed. In either case, the finished line of per~orations wi31 de~me a weakened tear or score line which will allow the central portion of the anterior oapsule to be removed or folded back. Access may then be had to the lens material 60 that further surgical procedures can be ~ormed, such RS disintegration and removal of a cataract. ~'hen these procedures are completed, all instrument~ are removed and the incision 11~ is sutured.
The handpiece 10 of Fig. 1 may be operated in a ~ingle-pulse or ~low automatic mode in order to ~llow the perforation6 126 to be made one ~t a time ~ with the interval between successive operating cycles being used to reposition the instrument tip at the location of the next desired 2 0 perforation . Infusion provided through the instrument tip via the flexible tube 22 oS the handpiece 10 maintains positive inlraocular pressure within the anterior chamber 120 of the eye during the time that the perforations are formed and prevents collapse of the cornea 116.
Although the present invention has been describes~ with reference to ZS specific preferred embodiments, the scope of the Lnvention is not limited to the details thereof. Various substitl3tions and modifications have been suggested in the foregoing descriptiola, and others will occur to those s)f ordinary 8~11 in the ~rt. All æuch ~ubstitution6 and modifications are intended to be embraced within the ~cope of the appended cl~ims.
.
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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An ophthalmic surgical instrument comprising a rigid elongated outer tubular member terminating in a distal end wall immediately adjoining a distal side opening; and a flexible elongated wire arranged within said outer tubular member and extending generally parallel to the longitudinal axis of said outer tubular member, said wire being axially movable within said outer tubular member and having its distal end positioned in proximity to the distal side opening in said outer tubular member, the distal end of said wire being formed with a single sharp distal tip adapted to form a discrete perforation in intraocular tissues; the distal end wall of the outer tubular member having a curved interior surface for deflecting the distal end of said wire so that the sharp distal tip of said wire projects through said distal side opening at an angle of about 90° relative to the longi-tudinal axis of the outer tubular member in response to axial movement of said wire toward the distal end of said outer tubular member.

2. An ophthalmic surgical instrument as claimed in claim 1, further comprising means slidable within said outer tubular member for supporting and imparting axial movement to said wire.

3. An ophthalmic surgical instrument as claimed in claim 2, wherein said slidable means comprises an inner tubular member coaxially and slidably arranged within said outer tubular member.

4. An ophthalmic surgical instrument as claimed in claim 3, wherein said outer tubular member is open at its proximal end, and wherein said inner tubular member has an open proximal end which extends beyond the open proximal end of the outer tubular member and an open distal end which terminates within said outer tubular member at a point behind the distal side opening thereof.

5. An ophthalmic surgical instrument as claimed in claim 1, wherein the distal end of and wire is curved in the direction of the distal side opening in the outer tubular member.

6. An ophthalmic surgical instrument as claimed in claim 3, wherein said wire comprises a flexible ribbon-like extension of said inner tubular member.

7. An ophthalmic surgical instrument as claimed in claim 6, wherein the distal end of said ribbon-like extension is curved in the direction of the distal side opening in the outer tubular member.

8. An ophthalmic surgical instrument as claimed in claim 6, wherein said outer tubular member is open fit its proximal end, and wherein said inner tubular member has an open proximal end which extends beyond the open proximal end of the outer tubular member and an open distal end which terminates in said ribbon-like extension at a point within said outer tubular member and behind the distal side opening thereof.

9. An ophthalmic surgical instrument as claimed in claim 8, further comprising a guide member affixed to the interior side wall of the outer tubular member at a position immediately behind the distal side opening therein, said guide member defining a narrow channel for guiding the movement of the ribbon-like extension in the vicinity of the distal side opening.

10. An ophthalmic surgical instrument as claimed in claim 9, wherein said guide member comprises a solid guide block, and wherein said channel is defined between an outer face of the guide block and the interior side wall of the outer tubular member.

11. An ophthalmic surgical instrument as claimed in claim 10, wherein said inner and outer tubular members are each circular in cross-section, and wherein said guide block comprises a solid cylinder with a narrow longitudinal section removed along one edge thereof.

12. An ophthalmic surgical instrument as claimed in claim 9, wherein said outer tubular member is provided with a second side opening spaced from said distal side opening and occupying a position between said guide member and the open distal end of said inner tubular member.

13. An ophthalmic surgical instrument as claimed in claim 12, wherein the distal end of the ribbon-like extension which extends beyond the channel defined by said guide member is curved in the direction of the distal side opening in the outer tubular member.

14. In an ophthalmic surgical apparatus comprising a handpiece portion and an instrument portion, said instrument portion comprising rigid inner and outer tubular members with the inner tubular member axially slidable within the outer tubular member, and said handpiece portion comprising power-operated means for axially reciprocating said inner tubular member within said outer tubular member to produce a desired function at the instrument tip, the improved instrument portion comprising: an outer tubular member terminating in a closed distal end immediately adjoining a distal side opening; an inner tubular member having an open distal end which terminates within said outer tubular member at a point behind said distal side opening; a flexible elongated wire arranged within said outer tubular member and carried by said inner tubular member, said wire extending generally parallel to the longitudinal axis of said outer tubular member and having its distal end positioned in proximity to the distal side opening in said outer tubular member, the distal end of said wire being formed with a single sharp distal tip adapted to form a discrete perforation in intraocular tissues; and means within the closed distal end of the outer tubular member for deflecting the distal end of said wire so that the sharp distal tip of said wire projects through said distal side opening at an angle relative to the longitudinal axis of the outer tubular member in response to axial sliding movement of the inner tubular member toward the distal end of said outer tubular member.

15. An ophthalmic surgical apparatus as claimed in claim 14, wherein the distal end of said wire is curved in the direction of the distal side opening in the outer tubular member.

16. An ophthalmic surgical apparatus as claimed in claim 14, wherein the distal end of the outer tubular member is closed by an end wall having a curved interior surface, and wherein said means for deflecting the distal end of the wire comprises said curved interior surface.

17. An ophthalmic surgical apparatus as claimed in claim 14, wherein said means for deflecting the distal end of the wire comprises a small diameter inner guide tube open at both ends and affixed within said outer tubular member in surrounding relationship with a portion of said wire.

18. An ophthalmic surgical apparatus as claimed in claim 17, wherein said inner guide tube is curved lengthwise through an arc of about 90°
with one end positioned within the distal side opening in the outer tubular member and pointing in a direction approximately normal to the longitudinal axis of the outer tubular member, and with its opposite end positioned in the interior of the outer tubular member and pointing in a direction approximately parallel to the longitudinal axis of the outer tubular member.

19. An ophthalmic surgical apparatus as claimed in claim 18, wherein said inner guide tube is affixed to the interior side well of the outer tubular member.

20. In an ophthalmic surgical apparatus comprising a handpiece portion and an instrument portion, said instrument portion comprising rigid inner and outer tubular members with the inner tubular member axially slidable within the outer tubular member, and said handpiece portion comprising power-operated means for axially reciprocating said inner tubular member within said outer tubular member to produce a desired function at the instrument tip, the improved instrument portion comprising: an outer tubular member terminating a closed distal end immediately adjoining a distal side opening; an inner tubular member having an open distal end which terminates in a ribbon extension extending generally parallel to the longitudinal axis of said outer tubular member, said ribbon extension having its distal end positioned in proximity to the distal side opening in said outer tubular member, the distal end of said ribbon extension being formed with a single sharp distal tip adapted to form a discrete perforation in intraocular tissues;
and means within the closed distal end of the outer tubular member for deflecting the distal end of said ribbon extension so that the sharp distal tip of said ribbon extension projects through said distal side opening at an angle relative to the longitudinal axis of the outer tubular member in response to axial sliding movement of the inner tubular member toward the distal end of said outer tubular member.

21. An ophthalmic surgical apparatus as claimed in claim 20, wherein the distal end of said ribbon extension is curved in the direction of the distal side opening in the outer tubular member.

22. An ophthalmic surgical apparatus as claimed in claim 20, further comprising A guide member affixed to the interior side wall of the outer tubular member at a portion immediately behind the distal side opening therein said guide member defining a narrow channel for guiding the movement of the ribbon extension in the vicinity of the distal side opening.

23. An ophthalmic surgical instrument as claimed in claim 22, wherein said guide member comprises a solid guide black, and wherein said channel is defined between an outer face of the guide blocks and the interior side wall of the outer tubular member.

24. An ophthalmic surgical instrument as claimed in claim 23, wherein said inner and outer tubular members are each circular in cross-section, and wherein said guide block comprises solid cylinder with a narrow longitudinal section removed along one edge thereof.

25. An ophthalmic surgical instrument as claimed in claim 24, wherein said outer tubular member is provided with a second side opening spaced from said distal side opening and occupying a position between said guide member and the open distal end of said inner tubular member.

26. An ophthalmic surgical instrument as claimed in claim 25, wherein the distal end of the ribbon extension which extends beyond the channel defined by said guide member is curved in the direction of the distal side opening in the outer tubular member.

27. An ophthalmic surgical instrument comprising a rigid elongated outer tubular member terminating in a closed distal end immediately adjoining a distal side opening; a flexible elongated wire arranged within said outer tubular member and extending generally parallel to the longitudinal axis of said outer tubular member, said wire being axially movable within said outer tubular member and having a sharp distal end positioned in proximity to the distal side opening in said outer tubular member; and means within the closed distal end of the outer tubular member for deflecting the distal end of said wire so that said wire projects through said distal side opening at an angle relative to the longitudinal axis of the outer tubular member in response to axial movement of said wire toward the distal end of said outer tubular member, said deflecting means comprising a small diameter inner guide tube open at both ends and affixed within said outer tubular member in surrounding relationship with a portion of said wire, said inner guide tube being curved lengthwise through an arc of about 90° with one end positioned within the distal side opening in the outer tubular member and pointing in a direction approximately normal to the longitudinal axis of the outer tubular member, and with its opposite end positioned in the interior of the outer tubular member and pointing in a direction approximately parallel to the longitudinal axis of the outer tubular member.

28. An ophthalmic surgical instrument as claimed in claim 27, wherein said inner guide tube is affixed to the interior side wall of the outer tubular member.

29. In an ophthalmic surgical apparatus comprising a handpiece portion and an instrument portion, said instrument portion comprising rigid inner and outer tubular members with the inner tubular member axially slidable within the outer tubular member, and said handpiece portion comprising power-operated means for axially reciprocating said inner tubular member within said outer tubular member to produce a desired function at the instrument tip, the improved instrument portion comprising an outer tubular member terminating in a closed distal end immediately adjoining a distal side opening, in inner tubular member having an open distal end which terminates within said outer tubular member at a point behind said distal side opening, a flexible elongated wire arranged within said outer tubular member and carried by said inner tubular member, said wire extending generally parallel to the longitudinal axis of said outer tubular member and having a sharp distal end positioned in proximity to the distal side opening in said outer tubular member, and means within the closed distal end of the outer tubular member for deflecting the distal end of said wire so that said wire projects through said distal side opening at an angle relative to the longitudinal axis of the outer tubular member in response to axial sliding movement of the inner tubular member toward the distal end of said outer tubular member, said deflecting means comprising a small diameter inner guide tube open at both ends and affixed within said outer tubular member in surrounding relationship with a portion of said wire, said inner guide tube being curved lengthwise through an arc of about 90° with one end positioned within the distal side opening in the outer tubular member and pointing in a direction approximately normal to the longitudinal axis of the outer tubular member, and with its opposite end positioned in the interior of the outer tubular member and pointing in a direction approximately parallel to the longitudinal axis of the outer tubular member.

30. An ophthalmic surgical apparatus as claimed in claim 29, wherein said inner guide tube is affixed to the interior side wall of the outer tubular member.