FR2981269A1 - Ophthalmic surgical instrument for capsulorhexis during cataract surgery, has cutting tool guide comprising loop groove on side of handling portion, where tool has transverse projection pin received in groove to slide along groove - Google Patents

Abstract

The instrument has an elongated cutting tool (1) comprising a cutting end introduced in an incision provided in an eye for realizing cut-out. The tool has a handling portion (1.2) to remain at exterior of the eye. A cutting tool guide (7) i.e. triangular plate (11), has a bearing on a side of the end for slidably and pivotably receiving a portion of the tool. The guide has a loop groove including shape corresponding to a contour of the cut-out on a side of the handling portion. The tool has a transverse projection pin received in the groove to slide along the groove.

Description

The invention relates to an ophthalmic surgery instrument, in particular for capsulorhexis. Capsulorhexis is usually performed during cataract surgery and consists of a circular cut of the capsule enclosing the crystalline so that it can be extracted before being replaced by an artificial intraocular implant. Capsulorhexis, lens extraction and placement of the intraocular implant in the hood are performed through an incision in the cornea. Since the incision is relatively small, the lens is divided into pieces that are sucked through the cutting and incision while the intraocular implant is generally in the form of a lens that is deformed to allow its introduction into the capsule via the incision before returning to its normal form once in place in the capsule.

The cutting of the capsule is usually performed by means of an instrument consisting of a needle having a curved end, or cystotome, introduced into the incision in the cornea. It is also known to use tongs whose free ends are curved. The practice of ophthalmic surgeons has shown that the regularity of the cutting is a factor limiting the risk of complications: the cut should be centered, have a sharp circular edge without tear initiation and have a diameter adapted to the operated eye and the implant set up. A number of solutions have been presented to obtain a regular cut. It is thus known for microscopically working surgeons to display in the microscopic visualization device a circular contour centered on the patient's eye in such a way that the surgeon visualizes the position and dimensions of the microscope. cut to be made. While the contour display of the cutout may assist the surgeon, the regularity of the cutout still depends greatly on his ability to handle the cutting tool. It is also known to use a cutting tool having a cutting end having dimensions corresponding at least partially to the shape of the cut to be made. Even if the cutting end comprises deployable or retractable parts, the cutting end has relatively large dimensions. It is therefore necessary to make an incision of larger size to allow the passage of the cutting end of the tool. However, we know that the risks of complications increase with the size of the incision. The use of clamps also has the disadvantage of creating leaks at the incision, forcing to provide a simultaneous introduction of liquid to maintain the intraocular pressure. An object of the invention is to provide a means to facilitate the realization of a regular surgical cut.

For this purpose, according to the invention, an ophthalmic surgical instrument is provided, in particular for capsulohexis, comprising an elongate cutting tool having a cutting end intended to be introduced into an incision made in the eye in order to carry out a surgical procedure. cutting and handling part to stay outside the eye. The instrument comprises a guide of the cutting tool, the guide comprising, on the side of the cutting end, a bearing receiving sliding and pivoting a portion of the cutting tool and, on the side of the handling part, a loop groove having a shape corresponding to a contour of the cut to be made, the tool having a transverse projection lug received in the groove to slide along thereof.

Thus, the movements of the cutting end of the tool are determined by the sliding of the lug in the groove of the guide and, the guide remaining outside the eye, the size of the incision is determined by function of the dimensions of the cutting end whose size is limited. The incision can therefore be small, thus reducing the astigmatism following the incision. Advantageously, the guide is in the form of a plate surrounded by a lateral flange having a portion in which is formed a bore to form the bearing and an opposite portion in which is formed a rectilinear groove for slidingly receiving an end of the tool protruding axially from the operating portion of the cutting tool.

This allows a mounting of the tool on the guide by simple interlocking. Advantageously, the groove comprises a blind portion starting in the loop to receive the pin during the introduction of the cutting end into the eye, the blind section being arranged to position the cutting end substantially at center of the cut. The positioning of the cut is achieved by positioning the cutting end of the tool opposite the center of the lens. Preferably, the cutting end comprises a blade having a pivot portion mounted to pivot on the tool and an active portion at least partially axially offset from the pivot portion.

The blade is thus fixed in a flag and will follow the movement of the tool promoting a clean cut of the capsule. Other characteristics and advantages of the invention will emerge on reading the following description of a particular non-limiting embodiment of the invention. Reference is made to the accompanying drawings, in which: FIG. 1 is a perspective view of an instrument according to the invention ready for the production of a capsulorhexis; FIG. 2 is a perspective view of the guide of this instrument; FIG. 3 is a perspective view from above of the tool of this instrument; FIG. 4 is an enlarged view in elevation of the cutting end of this tool; - Figure 5 is a perspective view and from below the tool.

With reference to the figures, the invention is described herein in application to an ophthalmic surgical instrument intended for producing capsulorhexis. The instrument comprises an elongated cutting tool, generally designated 1, having a cutting end 1.1 intended to be introduced into an incision made in the eye to make a cut and a handling part 1.2 to stay outside of the eye. The tool 1 comprises a solid body 2 from which extends a rod 3 having a free end forming the cutting end 1.1. The body 2 forms the handling part 1.2 and is provided with a handle 4 having here a shape of revolution projecting from an upper surface of the body 2.

The rod 3 has a free end provided with a terminal housing pivotally receiving a blade generally designated 5. The blade 5 has a pivot portion 5.1 mounted in the terminal housing for pivoting about an axis 6 parallel to the axis of the handle 4 and an active part 5.2, more particularly here the end of the cutting edge of the active part, axially offset with respect to the pivot part 5.1 and to the axis 6. The active part 5.2 is thus raised in flag with respect to the rod 3 and protrudes with respect to a lower surface of the body 2. The body 2 is here made of a plastic material such as a polyamide and is overmoulded on the rod 3. The rod 3 and the blade 5 are made of metal such as a stainless steel of medical grade. The instrument further comprises a guide of the cutting tool 1. The guide, generally designated 7, comprises, on the side of the cutting end 1.1 of the tool 1, a bearing 8 receiving sliding and pivoting a portion of the tool 1, here a portion of the rod 3 and, on the side of the handling portion 1.2, a loop groove 9 having a shape corresponding to a contour of the cut to be made. The bearing 8 allows the axial sliding of the rod 3 and a pivoting thereof about an axis centered on the bearing and normal to the plane of the groove 9. The loop groove 9 has a width sufficient to receive at sliding a lug 10 projecting from the lower surface of the body 2 coaxially with the handle 4. More specifically, the guide 7 is here in the form of a plate 11, here of substantially triangular shape, surrounded by a lateral flange 12 having a portion 13 (located at the point of the triangle) in which is formed a bore to form the bearing 8 and an opposite portion in which is formed a rectilinear groove 14 for slidingly receiving an end 2.1 of body 2 extending in axial projection from the operating part 1.2 in the alignment of the rod 3.

The groove 9 is formed in the plate 11 in such a way that the two flange portions mentioned above each extend on one side of said groove 9. The tool 1 thus moves in a plane substantially parallel to the plate 11 of the guide 7.

The groove 9 here comprises a blind portion 15 starting in the loop to receive the lug 10 during the introduction of the cutting end into the eye. The blind section 15 is arranged to position the cutting end 1.1 substantially in the center of the cutting. In use, an incision having been previously made in the cornea by means of a suitable tool, the cutting end 1.1 of the tool 1 is introduced into the incision while the lug 10 is received in the blind section 9 It should be noted that the cross-section of the rod 3 has a substantially circular shape which allows the sealing of the edges of the incision to be effected with the outer surface of the rod 3 in contact with said edges so that the capsulorhexis will be realized "in a sealed chamber". The cutting end 1.1 is positioned by the surgeon facing the center of the lens and is applied against the capsule to pierce it (an eye is shown very schematically in Figure 1). While firmly holding the guide 7, the surgeon will then move the operating portion 1.2 by means of the handle 4 of the body 2 to make travel to the lug 10 of the entire groove 9 thus making a cut of the appropriate shape. The flag blade 5 then follows the movements of the free end of the rod by orienting freely with respect to the latter, which allows a clean cut avoiding the risk of tearing. It will be noted in the figures that the groove 9 does not have a circular shape while the cut that one wants to obtain is circular in shape. It has been taken into account that the groove 9 is made on a flat surface (that of the plate 11) while the cut is made on a more or less spherical cap (the upper surface of the capsule).

Under the guide may be provided a surface of appropriate shape to rest on the body of the patient in the vicinity of the eye or the operated eye. Of course, the invention is not limited to the embodiment described but also encompasses any variant within the scope of the invention as defined by the claims. In particular, the materials may be different from those described: the body may for example be of metal and in one piece, or not, with the rod.

In addition, the blade can be fixed and in one piece, or not, with the rod. The cross section of the rod 3 may have a non-circular shape, and for example oval. The cross section of the shank 3, however, preferably has a shape that allows for sealing between the edges of the incision and the outer surface of the shank 3 in contact with said edges. The guide bearing may comprise elements facilitating the sliding and pivoting of the tool, such as rolling elements or a ball joint in which the rod is slidably received. The guide may have a different shape of a triangular shape and for example a trapezoidal or oval shape.

The portion 13 of the guide 7 can be provided with at least one tip arranged to clamp the eye to immobilize the guide 7 on the eye, or a spatula arranged to hang an edge of the incision itself. even for the same purpose. The guide 7 may comprise a surface on which the surgeon can bear during the making of the cut. The instrument of the invention may be adapted for a procedure other than capsulorhexis, such as, for example, for performing a cutting of the endothelium in the so-called DSAEK surgery operations ("Descemet's stripping automated endothelial keratoplasty") which concern transplanting a part of the thickness of the cornea.

Claims (8)

REVENDICATIONS1. Ophthalmic surgical instrument, in particular for capsulorhexis, comprising an elongated cutting tool (1) having a cutting end (1.1) intended to be introduced into an incision made in the eye in order to make a cut and a manipulating part (1.2) intended to remain outside the eye, characterized in that the instrument comprises a guide (7) of the cutting tool, the guide comprising, on the side of the cutting end, a bearing receiving sliding and pivoting a portion of the cutting tool and, on the side of the handling part, a groove (9) in a loop having a shape corresponding to a contour of the cut to be made, the tool comprising a transverse projection lug (10) received in the groove for sliding therealong. 2. Instrument according to claim 1, wherein the guide (7) is in the form of a plate (11) surrounded by a lateral flange (12) having a portion (13) in which is provided a bore for forming the bearing and an opposite portion in which is formed a rectilinear groove (14) for slidingly receiving an end (2.1) of the tool projecting axially from the operating portion of the cutting tool. 3. Instrument according to claim 1, wherein the groove (9) comprises a blind portion (15) starting extending in the loop for receiving the pin (10) during the introduction of the cutting end in the eye, the blind section being arranged to position the cutting end (1.1) substantially in the center of the cut. 4. Instrument according to claim 1, wherein the cutting end comprises a blade (5) having a pivot portion (5.1) mounted for pivoting on the tool and an active part (5.2) at least partially axially offset relative to the pivot part. 5. Instrument according to claim 1, wherein the actuating portion (1.2) comprises a handle (4) projecting transversely of the actuating portion in line with the lug (10). 6. Instrument according to claim 1, wherein the tool comprises a body (2) of plastic material from which extends a rod (3) having a metal free end forming the cutting end (1.1). 7. Instrument according to claim 1, wherein a portion (13) of the guide (7) adjacent the bearing is provided with at least one member of its immobilization relative to the eye. 8. The instrument of claim 7, wherein the immobilizing member comprises a tip for clamping the eye or a spatula arranged to be attached to an edge of the incision.