United States Patent (19)
`Skjaerpe
`
`54 MICROSURGICAL INSTRUMENT
`76) Inventor:
`Finn Skjaerpe, Nedreveien 1,
`Stavanger, Norway, N-4000
`438,891
`Appl. No.:
`21
`Mar. 12, 1982
`22) PCT Filed:
`PCT/NO82/00014
`86) PCT No.:
`Oct. 29, 1982
`S 371 Date:
`Oct. 29, 1982
`S 102(e) Date:
`87). PCT Pub. No.: WO82/03168
`PCT Pub. Date: Sep. 30, 1982
`Foreign Application Priority Data
`(30)
`Mar. 12, 1981 NO Norway ................................. 810849
`(51) Int. Cl. .............................................. A61B 17/32
`52) U.S. C. .................................................... 128/305
`58 Field of Search ................... 128/303 R, 305, 304,
`128/303.14, 751, 753, 754, 757; 30/124, 130,
`172, 299, 279
`
`56
`
`References Cited
`U.S. PATENT DOCUMENTS
`l, 167,014 1/1916 O'Brien ........................... 28/751 X
`2,133.208 10/938 Nellis ................................ 30/299 X
`2,668,536 2/1954 Farries et al. ....................... 128/305
`
`Patent Number:
`11
`(45) Date of Patent:
`
`4,501,274
`Feb. 26, 1985
`
`3, 18555 5/1965 Saten et al. .................... 28/303 R
`4,315,511 2/982 Chin............... . . . . . . . . . . . . . . . . . . 128/304 X
`FOREIGN PATENT DOCUMENTS
`452338 12/1974 U.S.S.R............................... 128/305
`Primary Examiner-Michael H. Thaler
`Attorney, Agent, or Firm-Watson, Cole, Grindie &
`Watson
`ABSTRACT
`57)
`A microSurgical instrument for performing selective
`trabeculectomy in surgical treatment of glaucoma in
`cludes a flexible probe (A) and a cutting member (C)
`fixed to the same. The cutting member comprises two
`knife blades (C1,C2) protruding in different directions
`from the probe and each providing at least one sharp
`edge (E1,E2) turned towards a free end of the probe.
`The instrument is designed to be pulled between two
`incisions in the eye wall with the probe foremost
`through the Canal of Schlemm at the transition between
`cornea and sclera, thereby cutting away the inner wall
`of the canal and the corresponding part of the trabecu
`lar meshwork located in the canal. The aqueous humour
`of the eye then gains access to the outer wall of the
`Canal of Schlemm with its drainage outlets leading out
`of the eye.
`
`13 Claims, 5 Drawing Figures
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`Petitioner - New World Medical
`Ex. 1016, p. 1 of 7
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`

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`U.S. Patent Feb.26, 1985
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`Sheet 1 of 3
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`4,501,274
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`Petitioner - New World Medical
`Ex. 1016, p. 2 of 7
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`

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`U.S. Patent Feb.26, 1985
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`Sheet 2 of 3
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`4,501,274
`
`
`
`Petitioner - New World Medical
`Ex. 1016, p. 3 of 7
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`

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`U.S. Patent Feb.26, 1985
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`Sheet 3 of 3
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`4,501,274
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`
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`Petitioner - New World Medical
`Ex. 1016, p. 4 of 7
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`

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`1.
`
`MICROSURGICAL INSTRUMENT
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`BACKGROUND OF THE INVENTION
`The present invention relates to a microsurgical cut
`ting instrument to be used in surgical treatment of glau
`coma by means of a novel operational procedure, which
`significantly may be called 'selective trabeculectomy'.
`Glaucoma is an ailment resulting in increased inner
`pressure in the eyeball. Within the eye, aqueous humor
`is produced at a fairly constant rate. This liquid is
`drained out through filterlike tissue (trabecular mesh
`work) in the area between iris and cornea into a collec
`tor canal running circularly along the transition be
`tween cornea and sclera (Canal of Schlemm), and from
`this canal through 20-30 drainage outlets in the eye wall
`into blood vessels (water veins).
`The cause of glaucoma is believed to be a type of
`"clogging" of the trabecular meshwork, so that the
`20
`outflow resistance increases. Then, also the pressure
`increases to allow the same volume of liquid to be
`drained out per time unit. All treatment aims at reduc
`ing the eye pressure. Such treatment is primarily medi
`cal, but when this is intolerable and/or insufficient,
`25
`surgical treatment is used.
`The surgical treatment may be subdivided according
`to three principles, namely:
`1. Operations aiming at reduced production of aque
`ous humour.
`30
`2. Fistulizing procedures, i.e., surgical provision of
`artificial slits in the eye walls through which the liquid
`may seep out of the eye.
`3. Operations on the trabecular meshwork. Existing
`procedures of this kind are of two types, i.e.:
`(a) Approach through the anterior chamber of the
`eye by means of goniotomy or cautery of the trabecular
`meshwork with laser beams.
`(b) Approach through the Canal of Schlemm. Such
`approach consists in opening this canal through a radial 40
`incision in the eye wall above the canal and insertion of
`a blunt probe or probe means with a cutting edge
`(trabeculotome). This instrument is then manipulated in
`such a way that it tears open or cuts through the trabec
`ular meshwork into the anterior chamber of the eye.
`45
`With such procedure a narrow slitlike opening is
`formed through the trabecular meshwork. Such slits
`exhibit, however, a considerable tendency to close.
`SUMMARY OF THE INVENTION
`In order to inhibit such closure it is an object of the
`present invention to provide a microsurgical instrument
`which through appropriate use may form a permanent
`opening from the anterior chamber of the eye to the
`Canal of Schlemm by selective removal of the inner
`55
`wall of this canal along a certain sector. In this manner
`the aqueous humour gains direct access to the outer
`wall of the Canal of Schlemm, which has outlets or
`drainage canals, so that normal drainage of aqueous
`humour may be reestablished.
`60
`Thus, the invention concerns a microsurgical instru
`ment for performing selective traveculectomy in surgi
`cal treatment of glaucoma, the instrument including
`flexible probe means and a cutting member fixed to the
`same. With this background the general inventive fea
`65
`ture of the instrument is that the cutting member com
`prises two knife blades protruding in different directions
`from the probe and each providing at least one sharp
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`4,501,274
`2
`cutting edge turned towards a free end of the probe
`realS.
`This instrument may be called a trabeculectome, as it
`is designed to be pulled through the Canal of Schlemm
`along a certain peripheral sector of the eye. By this the
`inner wall of the canal and the corresponding portion of
`the 0.1 mm thick trabecular meshwork are cut away.
`AS indicated, the trabeculectome consists of probe
`means and a cutting member. The probe means is pref.
`erably knob-shaped at the extreme end and made of
`flexible material, but this still sufficiently rigid to be
`inserted into and directed through the Canal of
`Schlemm. The cutting member has a double-cutting
`knife, the two cutting edges of which are angularly
`separated to such extent that the issuing V-form fits into
`the scleral groove in the eye wall, in which the trabecu
`lar meshwork is embedded. Advantageously, the cut
`ting member is assymetrical in such a manner that the
`knife blade that projects perpendicularly into the ante
`rior chamber towards the iris is short, whereas the blade
`that projects obliquely into the anterior chamber and
`forms a small angle with the back side of the cornea is
`longer. This feature stabilizes the correct position of the
`knife.
`The probe means of the trabeculectome is directed
`through an incision in the eye wall into and along the
`Canal of Schlemm, and is pulled out through another
`incision at a certain distance from the first one. The
`cutting member of the trabeculectome is pulled after the
`probe means through the Canal of Schlemm with the
`two knife edges projecting into the anterior chamber of
`the eye and thereby cutting away a strip of the trabecu
`lar tissue and the inner wall of the Canal of Schlemm
`which are located between the cutting edges. This tis
`sue strip is preferably removed together with the
`trabeculectome when it is pulled out through the sec
`ond incision in the eye wall. Such removal of the tissue
`strip may be secured by mounting one or more hooks in
`the angle between the two knife edges in order to catch
`the cut away strip and carry it out of the eye.
`The microsurgical instrument according to the inven
`tion allows a surgical procedure which secures a perma
`nent, broad opening between the anterior chamber of
`the eye and the outlets from the Canal of Schlemm by
`removing the trabecular meshwork and the inner wall
`of the canal. Tissue removal together with maintained
`cell casing on the outer wall of the Canal of Schlemm
`make a closure of this opening improbable, even after a
`long period of time.
`Experiences with this method up to now suggest a
`low rate of complications, so that the operational indi
`cations probably may be extended. This means that the
`patients may be operated at an earlier stage and thus
`expensive and troublesome medical treatment is
`avoided.
`The invention will now be explained in more detail
`with reference to exemplified embodiments as shown in
`the accompanying drawings.
`DESCRIPTION OF THE DRAWINGS
`FIG. 1 shows a first embodiment of the instrument in
`a cross-section through the cutting member at a right
`angle to the longitudinal axis of the probe means.
`FIG. 2 is a side elevation of the instrument shown in
`FIG. 1.
`FIG. 3 shows the instrument in FIGS. 1 and 2 in
`perspective view.
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`Petitioner - New World Medical
`Ex. 1016, p. 5 of 7
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`wall. If the cutting member is located approximately
`FIG. 4 is a side elevation of another embodiment of
`the instrument.
`centrally on the probe, the protruding knife blades may
`FIG. 5 shows a cross-section through the cutting
`further be provided with a cutting edge on both sides,
`member at a right angle to the longitudinal axis of the
`so that the instrument may be effectively pulled in both
`probe means in the embodiment of FIG. 4, and
`directions through the Canal of Schlemm.
`FIG. 6 shows a perspective view of a further embodi
`Although the cutting edges are shown in the drawing
`ment of the inventive instrument.
`to form essentially right angles with the longitudinal
`axes of the probe means, the edges may also according
`DETAILED DESCRIPTION OF THE
`to the invention advantageously be inclined at an angle
`PREFERRED EMBODIMENTS
`of 0 axis (see FIG. 4). This angle 0 can vary from 45 to
`The probe means A is in the embodiment shown in
`90'. An inwards directed radial force is then exercised
`FIGS. 1-3 a monofilament of nylon, which is fused at
`against the tissue strip during the movement of the
`one end to form a rounded knob. The other end of the
`cutting member through the Canal of Schlemm.
`probe is inserted into a hole in steel member B and
`I claim:
`rigidly clamped to this member. The knife member C is
`1. A microsurgical instrument for performing selec
`formed from a 1/100-5/100 mm thick stainless steel foil,
`tive trabeculectomy in the surgical treatment of glau
`which is finely sharpened at the front side E1 and bent
`coma, said instrument including an elongated, flexible
`into an approximate V-form adapted to the local ana
`probe means having a first end and a second end, and a
`tomical features of the eye at the Canal of Schlemm and
`cutting member attached to said probe means at a point
`the trabecular meshwork. The member C is fixed to the
`20
`spaced apart from said first end, said cutting member
`member B and thereby also the probe A by means of a
`including
`two-component epoxy glue. A point welding technique
`two knife blades which are separated so as to fit into
`may also be used if the probe means is mounted on the
`the scleral groove of the eye wall in which trabecu
`member B after the welding step. An arrow above the
`lar meshwork is embedded and which protrude in
`probe in FIG. 2 shows the pulling direction in use.
`different transverse directions from the probe
`Between the knife blades a barbed hook D is fixed to the
`means in order to extend from said groove into the
`steel member B in order to catch the tissue strip which
`anterior chamber of the eye, thus embracing a strip
`is cut free between the knives. This hook is also fastened
`of said trabecular meshwork, each said knife blade
`by means of epoxy resin. Finally, a layer of epoxy resin
`providing a first edge which faces said first end of
`is applied to the joints and transitions between the steel
`said probe means and a second edge which faces
`member B and the probe. A to provide a completely
`away from said first end of said cutting means, at
`smooth surface. Teflon and similar polymers may also
`least said first edge being sharp for cutting, and
`be used as covering layer and silicone is considered
`at least one catching device located between said two
`particularly advantageous for this purpose.
`knife blades at a point spaced farther from said first
`Another embodiment is illustrated in the FIGS. 4 and
`end of said probe than said cutting edges of said
`5.
`knife blades, each catching device retaining
`In this case the probe is made of flexible metal and
`thereon trabecular tissue which has been cut by
`welded to the knife member. The extreme rear end of
`said knife blades.
`the probe is bent forward between the knife blades to
`2. A microsurgical instrument as defined in claim 1,
`form a small sharp hook D. All joints are provided with
`wherein a first blade of said two knife blades extends
`a cover of epoxy resin and the probe is furnished with a
`away from a longitudinal axis defined by said elongated
`layer of resin at the end to form a finely rounded knob.
`probe means a distance less than said second blade of
`The knife blades C1, C2 need not necessarily have a
`said two knife blades, said first blade being flat and the
`free end. Thus, the extreme ends of the knife blades may
`second blade being curved so as to conform to the
`well be interconnected to form a closed knife blade ring,
`45
`e.g., of approximate triangular shape. The cut-away
`boundary surface of the tissue to be cut away.
`3. A microsurgical instrument as defined in claim 1,
`tissue strip may then be captured by closing the rear
`opening of the knife ring, thereby catching the strip in
`wherein each catching device comprises a hook means
`which is curved toward the first end of said probe
`the "container' thus formed. This embodiment of the
`inventive instrument is depicted in FIG. 6.
`eaS
`The instrument must necessarily be quite small to
`4. A microsurgical instrument as defined in claim 1,
`allow the intended surgical treatment of the eye. Thus,
`wherein said two knife blades extend upwardly from a
`longitudinal axis defined by said elongated probe means
`in the illustrated embodiments the probe has a diameter
`of approximately 0.25 mm and a length of the order of
`at an angle 6 of between 45° and 90'.
`magnitude 4-8 cm and rather freely adaptable to the
`5. A microsurgical instrument as defined in claim 1,
`55
`requirements of the eye surgeon. The shorter knife of
`wherein said elongated probe means is made of a nylon
`the cutting member may suitably have a length of about
`monofilament and wherein said cutting member in
`0.7-1.0 mm, while the longer, preferably curved knife
`cludes a metallic holder which is fixedly connected to
`may have a length of 1.5-1.8 mm. The width of the
`said nylon monofilament.
`s
`knives may be of the order of magnitude 0.3 oc 0.5 mm.
`6. A microsurgical instrument as defined in claim 5,
`60
`In the embodiments shown in the drawings and de
`wherein said knife blades and said catching devices are
`scribed above the cutting member is fixed at one end of
`attached to said metallic holder.
`the probe means. However, the cutting member may
`7. A microsurgical instrument as defined in claim 1,
`well be fixed to the probe at another location, e.g., on
`wherein said elongated probe means is made of a flexi
`the central part of the same. The portion of the probe
`ble metallic material.
`65
`projecting from the rear side of the cutting member may
`8. A microsurgical instrument as defined in claim 7,
`then be used for improved steering of the instrument,
`wherein said cutting means is welded to said elongated
`when it is guided between the two incisions in the eye
`metallic probe means.
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`Petitioner - New World Medical
`Ex. 1016, p. 6 of 7
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`ak
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`4,501,274
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`9. A microsurgical instrument as defined in claim 8,
`of said knife blades to create a container area therebe
`wherein said probe means is coated with a plastic mate-
`tWeen,
`12. A microsurgical instrument as defined in claim 11,
`rial.
`wherein said means connected between the second
`10. A microsurgical instrument as defined in claim 1,
`5 edges of said knife blades is a plate.
`13. A microsurgical instrument as defined in claim 1
`wherein said cutting member is attached to the second
`wherein said cutting member is made of a hard plastic
`end of said elongated probe means.
`11. A microsurgical instrument as defined in claim 1,
`material.
`wherein means are connected between the second edges
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`Petitioner - New World Medical
`Ex. 1016, p. 7 of 7
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