Instrument for fixating the eye during cataract surgery

A method and apparatus for fixating an eye during ocular surgery, including inserting a two-pronged tool through an incision in the cornea into the anterior chamber. The two prongs prohibit movement of the eye in all directions. An alternate embodiment provides for use of two such two-pronged tools which are coupled together and each of the two-pronged tools is inserted in the incision and help to prohibit movement of the eye.

BACKGROUND OF THE INVENTION
 The present invention pertains to instruments for fixating the eye during
 ocular surgery such as cataract extraction by the small incision
 technique, commonly known as Phacoemulsification or Phaco technique and
 other operations of the anterior segment of the eye that are performed
 under local anesthesia.
 In recent years, two surgical techniques for removing a cataract from the
 eye are employed. The large incision technique and the small incision or
 Phaco technique.
 In the large incision technique, an incision (approximately 8-10 mm),
 almost half of the circumference of the cornea is made, and the cataract
 is expressed or squeezed out of the eye manually. The advantage with this
 technique is that it is much easier to perform. The disadvantages are the
 longer time to recuperate, and it produces more astigmatism.
 In the small incision or Phaco technique, a small incision, approximately
 three (3) mm long is made on the peripheral margin of the cornea (usually
 temporal). Then a needle or sharp forceps is used to puncture the anterior
 lens capsule and tear a circular opening (capsulorhexis) to create access
 to the cataractous lens cortex and nucleus through the corneal incision
 and capsular opening. An ultrasonic cutting tip is then inserted inside
 the eye to remove the cataract. The advantages with this technique are the
 stronger wound, faster recuperation, and less astigmatism.
 Ophthalmologists have continued to improve the Phaco technique. One such
 improvement is the recent change from needle-block anesthesia injections
 which paralyze the eye to a topical anesthesia, administered through eye
 drops. The eye drops eliminate the swelling, bruising, discomfort and
 trauma to the tissues around the eye which are often associated with
 needle-block anesthesia injections and further eliminates the possible
 complication of inadvertent ocular perforation from the anesthetic needle.
 While the topical anesthesia has many beneficial aspects, including freedom
 of movement immediately after the completion of the Phaco procedure, it
 also allows the undesirable free movement of the eye during the surgical
 procedure.
 Ophthalmologists have often used three different approaches to fixate the
 eye under such circumstances. One has been to use a toothed ring that
 extends around the perimeter of the cornea which is pressed down into the
 sclera. Another approach has been to use forceps to grab the outside of
 the eye to restrict movement. Alternatively, it is possible to use a
 special diamond knife to hold the eye steady after one of the two
 incisions is made.
 While these approaches have been used in the past, each has serious
 drawbacks. The toothed ring requires an increased pressure in the eye when
 the surgeon presses the ring into the sclera. During the part of the
 operation where the anterior capsule is tom open (capsulorhexis), the
 increased intraocular pressure makes the procedure more difficult and
 increases the likelihood of a complication. The approach using forceps to
 restrain eye movement has the drawback that the forceps on occasion
 accidentally release the eye because it is difficult to grasp the eye
 firmly, or in other situations, tear blood vessels and cause bleeding.
 Using the knife to hold the eye prevents movement in three directions (to
 either side or toward the handle), but not in the fourth direction--toward
 the point of the knife. The two other drawbacks of the diamond knife are
 the expense of the instrument and the difficulty of reinsertion after
 removal. It is difficult to reinsert the blade in the same incision
 without creating a new cut.
 Consequently, there is a need for improvement in instruments and methods
 for fixating the eye during cataract surgery.
 SUMMARY OF THE INVENTION
 It is an object of the present invention to provide a method and apparatus
 for restraining eye movement during intraocular surgery.
 It is a feature of the present invention to include a multi-pronged eye
 restraining tool.
 It is an advantage of the present invention to provide for restraining eye
 movement in all directions.
 It is another feature of the present invention to deploy the multi-pronged
 tool in the paracentesis site or side port of a Phacoemulsification
 surgery or other anterior segment surgery.
 It is another advantage of the present invention to limit the additional
 trauma or side effects associated with eye fixation.
 The present invention is a method and apparatus for restraining eye
 movement during ocular surgery which is designed to satisfy the
 aforementioned needs, provide the previously stated objects, include the
 above-listed features and achieve the already articulated advantages.
 Accordingly, the present invention includes an apparatus having a handle
 member, a longitudinal shaft coupled to the handle member, a first
 protuberance coupled to the shaft member for insertion through an incision
 in the eye, the first protuberance extending in a first direction from the
 shaft member, a second protuberance coupled to the shaft member at a
 predetermined distance from the first protuberance and extending in a
 second direction from the shaft member, the second protuberance for
 restricting the penetration of the first protuberance into the eye.

DETAILED DESCRIPTION OF THE DRAWINGS
 Now referring to the drawings, where like numerals refer to like matter
 throughout, and more particularly to FIG. 1, there is shown a
 cross-sectional view of a typical human eye. The front part of the eyeball
 is a clear transparent structure called the cornea IO. The back surface of
 the cornea is lined with a layer known as the endothelium 12. The
 endothelium borders the anterior chamber 13. Posterior to the cornea,
 endothelium, and anterior chamber is the iris 16, the colored part of the
 eye (brown, blue or green eyes). The opening in the center of the iris is
 the pupil 14. Behind the iris is the lens 18 of the eye. A thin capsule
 surrounds the lens. The side toward the cornea is called anterior capsule.
 A normal lens is clear and transparent. However, if the lens 18 becomes
 cloudy or opaque, as in old age, it is often called a cataract, and
 surgery is used to remove and replace this lens with a clear artificial
 lens called an intraocular lens implant.
 Now referring to FIG. 2, there is shown a perspective view of the
 multi-pronged apparatus of the present invention generally designated 200,
 having a handle 202 and an elongated shaft 204 coupled to the handle, and
 distal to the handle are protuberances 206 and 208.
 Preferably, the shaft member 204 and the protuberances 206 and 208 are
 constructed of a single piece of surgical steel or titanium with the
 handle 202 being attached thereto. In some circumstances, the entire
 device 200 will be constructed of a single piece of surgical steel or
 titanium. Handle 202 is shown as a device which is intended to be gripped
 by a medical professional; however, in an alternate embodiment, handle 202
 could be a sleeve, into which a finger is inserted, or any means of
 strapping or other coupling the tool to a human hand could be substituted.
 Now referring to FIG. 3, there is shown the distal portion of the apparatus
 200 of the present invention which includes a portion of the distal
 portion of the elongated shaft 204; it also shows a first protuberance 206
 and a second protuberance 208. The apparatus 200 is shown having a
 constant width dimension D which is typically somewhere between 0.1 mm and
 1.5 mm, but preferably is approximately 0.5 mm in width. The height of
 protuberances 206 and 208 are a matter of design choice; however, the
 height of protuberance 206 is preferably on the order of 0.7 mm while the
 height of protuberance 208, which is dimension H, is preferably on the
 order of 1.2 mm. The separation of the leading edge 210 of protuberance
 206 from the leading edge 212 of the protuberance 208, which is dimension
 S, is preferably on the order of 2 mm.
 In an alternate embodiment, the protuberance 206 will extend from the
 elongated shaft 204 at an angle larger than 90.degree. so that the
 protuberance tip 214 extends further from the handle 202 (FIG. 2) than if
 the protuberance had been at a 90.degree. angle. This provides for a
 variable separation s' between the leading edge 210' and the leading edge
 212.
 Now referring to FIG. 4, there is shown an elevational view of the
 apparatus of the present invention generally designated 200, which shows
 the shaft member 204, first protuberance 206 and second protuberance 208.
 Now referring to FIG. 5, there is shown an enlarged sectional view of a
 portion of the eye generally designated 500 with the apparatus of the
 present invention 200 disposed in the eye in accordance with the present
 invention. The anterior lens capsule 502 is shown to be partially opened
 with a bent needle (cystotome) 504 as the eye is shown to be fixated by
 the apparatus of the present invention 200. The invention's greatest
 utility is often during the step when the anterior capsule is opened. The
 apparatus 200 of the present invention is shown inserted through a
 separate incision 506 often referred to as a side port incision through
 the peripheral cornea. Protuberance 206 at the distal end of shaft member
 204 is inserted through the side port incision 506 and enters the anterior
 chamber. Protuberance 208 restricts the protuberance 206 from extending
 too far into the anterior chamber. In operation, the surgeon or an
 assistant to the surgeon will insert the device 200, including
 protuberance 206, through the incision and may choose to rotate the device
 200 so that the direction of the first protuberance is perpendicular to
 the longest dimension of the incision or sliding the device 200 along a
 length of the incision, thereby allowing for a more firm contact between
 the protuberance 206 and the edge of the corneal incision. The surgeon or
 assistant to the surgeon may then manually restrain eye movement by
 applying a slight outwardly pressure and/or by firmly holding the handle
 202 (not shown). The length and position of the incision is a matter of
 choice by the surgeon, and it may be made in and through other sections of
 the eye.
 Now referring to FIG. 6, there is shown a perspective view of an apparatus
 of the present invention generally designated 600, which is attached to a
 human finger 601. Apparatus 600 includes a shaft 604, having a first
 protuberance 606 and a second protuberance 608, which are similar in
 arrangement and construction to shaft 204 and protuberance 206 and 208 of
 FIG. 2. Shaft 604 is coupled to a human finger 601 by strapping apparatus
 630 which includes a strap having a first end 632 and a second end 634.
 Preferably a fastener of some type is used in area 636. The fastener in
 area 636 is preferably a Velcro fastener, but any other suitable fastener
 such as adhesives, snaps, buttons, ties could be substituted.
 Now referring to FIG. 7, there is shown a perspective view of an alternate
 apparatus of the present invention generally designated 700, which
 includes a first eye gripping member 702 and a second eye gripping member
 704. Members 702 and 704 are preferably joined together at proximal end
 705 and are capable of distension when a force is applied by the
 operator's fingers in a first direction 710 and a second direction 712.
 When force is applied in directions 710 and 712, members 702 and 704 are
 thereby caused to move in directions 722 and 724 respectively. Apparatus
 700 is also shown having a distal end 708 which is inserted into a human
 eye 709 through a side port incision 706.
 Now referring to FIG. 8, there is shown an enlarged view of the distal end
 708 of the apparatus 700 of FIG. 7. Member 704 is shown having a top
 proximal protuberance 802 and a top distal protuberance 804 which are
 separated by a distance 8A which is preferably on the order of 1.5 mm. Top
 distal protuberance 804 is shown having a height dimension 8B which is
 preferably on the order of 0.25 mm. Member 702 is shown having a bottom
 proximal protuberance 808 and a bottom distal protuberance 806 which are
 separated by a distance 8D which is preferably similar to the distance 8A.
 Similarly, distance 8C representing the height dimension of bottom distal
 protuberance 806 is preferably similar to the distance 8B.
 Now referring to FIG. 9, there is shown a perspective view of the apparatus
 700 disposed in a side port incision during an operation.
 Now referring to FIGS. 7-9, it can be seen that the distal ends of the
 members 704 and 702 are caused to separate and more firmly engage the
 cornea 10 when the apparatus 700 is inserted in a side port incision
 during an operation and the members 702 and 704 are pressed in directions
 710 and 712 by the physician.
 The apparatus 700 is preferably made of material similar to apparatus 200
 of FIG. 2. However, it is understood that the desire for flexing the
 members and biasing the members either toward a closed distal end or an
 open distal end may result in different choices of material, dimensions,
 coupling and biasing techniques all of which are well known in the art.
 Throughout this description, cataract surgery has been used merely as an
 example of a type of surgery related to the present invention. It should
 be understood that the present invention may be applicable to other ocular
 surgery that requires eye fixation.
 It is thought that the method and apparatus of the present invention will
 be understood from the foregoing description and that it will be apparent
 that various changes may be made in the form, construction, steps and
 arrangement of the parts and steps thereof, without departing from the
 spirit and scope of the invention or sacrificing all of their material
 advantages. The form herein described is merely a preferred or exemplary
 embodiment thereof.