Ophthalmic surgical instruments for splitting fibrous tissue inside the eye

Abstract

This invention provides an ophthalmic surgical instrument that reduces the risk of damaging non-excised tissue even when used at a large insertion angle. [Solution] The invention comprises a long-axis shaft 10 and a split portion 20 projecting away from the longitudinal direction of the shaft. The shaft has a front surface located in the direction of the protruding split portion and a rear surface located on the opposite side of the protruding direction. The split portion has a tip where the thickness in the longitudinal direction of the shaft is minimized in the direction of the protruding direction, a top surface which is the connection surface between the tip and the front surface of the shaft, and a bottom surface which is the connection surface between the tip and the rear surface of the shaft. In a side view, the center point of the reference cross section, which is perpendicular to the horizontal tangent line that is the first to be parallel to the horizontal axis extending in the longitudinal direction of the shaft, and which passes through the point of contact between the horizontal tangent line and the top surface, is set back toward the rear surface of the shaft than the first axis which passes through the center point that has the most overlap in a front view among the center points of a plurality of reference cross section parallel to the reference cross section.

Description

[Technical Field]

[0001] The present invention relates to ophthalmic surgical instruments, and more particularly to ophthalmic surgical instruments for cleaving fibrous tissue within the eye. [Background technology]

[0002] The trabecular meshwork is located between the anterior chamber and Schlemm's canal of the eye, and acts like a filter through which aqueous humor passes before flowing into Schlemm's canal.

[0003] It is known that impaired trabecular meshwork function can lead to increased intraocular pressure and cause glaucoma, as it obstructs the outflow of aqueous humor. One of the causes of impaired trabecular meshwork function is the decrease in elasticity of the trabecular fibers due to aging.

[0004] One known treatment for impaired aqueous humor outflow due to trabecular meshwork dysfunction is surgical removal of the trabecular meshwork.

[0005] Patent Document 1 relates to a device for cutting a trabecular meshwork, a platform for lifting a portion of the trabecular meshwork outward from the outer wall of a Schlemm's canal, the platform comprising a tip on the distal side of the platform and an upper surface extending from the distal side of the platform to the proximal side opposite the distal side of the platform, and a first side and a second side extending from the upper surface, the first side and the second side being parallel to each other. The device is disclosed comprising a side and a second side, a bottom surface opposite the top surface, defined by a first projection below the first side and a second projection below the second side, the first and second projections separated by a gap, and a first lateral element and a second lateral element for creating a first and second incision through the trabecular meshwork, the first and second lateral elements extending from the proximal side of the platform.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the device disclosed in Patent Document 1 has a risk of damaging non-excised tissues (sclera, Schlemm's canal, etc.) as the insertion angle with respect to the device insertion port in the eye increases.

Means for Solving the Problems

[0008] The inventor has developed an ophthalmic surgical instrument in which the thickness of the shaft of the ophthalmic surgical instrument is partially thinned and a cleavage part for cleaving fibrous tissue is shifted with respect to the axis of the shaft. Such an ophthalmic surgical instrument can reduce the risk of damaging non-excised tissues even when used at a larger insertion angle than conventional ophthalmic surgical instruments, and the present invention has been completed.

[0009] [1] An object of the present invention is ​​​​​​​​​​​​​​​​​​​​​​​ a bottom surface serving as a connection surface between the tip and the rear surface of the shaft, and comprising in a side view, among the tangents of the surface or point that transitions from the top surface to the front surface of the shaft, the horizontal tangent that is first parallel to the horizontal axis extending in the longitudinal direction of the shaft is perpendicular, and the center point of the reference cross-section passing through the contact point between the horizontal tangent and the top surface retreats toward the rear surface side of the shaft from the first axis passing through the center point that overlaps the most in a front view among the center points of a plurality of reference cross-sections parallel to the reference cross-section. An ophthalmic surgical instrument characterized by this is to provide.

[0010] The ophthalmic surgical instrument according to the present invention can reduce the risk of damaging non-excised tissues even when used at a larger insertion angle than conventional ophthalmic surgical instruments.

[0011] [2] In the ophthalmic surgical instrument according to [1], the shaft has a region with a constant thickness on the proximal side, the thickness of the shaft is the thinnest at the contact point, and the thickness of the shaft may increase in the proximal direction from the contact point up to the region with a constant thickness of the shaft.

[0012] [3] In the ophthalmic surgical instrument according to [1] or [2], the cleavage part has a first blade surface provided between the tip and the bottom surface, and a second blade surface provided between the tip and the top surface, and may further comprise in a side view, the second angle formed by the second axis that bisects the first angle formed by the first blade surface and the second blade surface and the first axis may be 60 to

[0013] 100 degrees on the top surface side.

[0013] [4] Another object of the present invention is an ophthalmic surgical instrument for cleaving fibrous tissues in the eye, and the ophthalmic surgical instrument has a long-axis-shaped shaft, and A split portion protruding away from the longitudinal direction of the shaft and Equipped with, The above shaft is The front surface of the shaft located in the direction of the protruding portion of the split, The rear surface of the shaft located on the opposite side of the above-mentioned protruding direction, The shaft side surface which connects the front surface of the shaft and the rear surface of the shaft Equipped with, The above-mentioned cracked portion is, The tip of the shaft where the thickness in the longitudinal direction is minimized in the direction of the protruding split portion, The top surface which forms the connection surface between the tip and the front surface of the shaft, The bottom surface which serves as the connection surface between the tip and the rear surface of the shaft, The side surface of the split, which is the connecting surface between the top surface and the bottom surface mentioned above, Equipped with, In a side view, among the tangents of the plane or point transitioning from the top surface to the front surface of the shaft, the center point of the reference cross section that is perpendicular to the horizontal tangent that first becomes parallel to the horizontal axis extending in the longitudinal direction of the shaft, and that passes through the point of contact between the horizontal tangent and the top surface, is set back toward the rear surface of the shaft than the first axis that penetrates the center point with the greatest overlap in a front view among the center points of a plurality of reference cross sections parallel to the reference cross section. An ophthalmic surgical instrument characterized in that the top surface, bottom surface, front surface of the shaft, and / or rear surface of the shaft have different surface roughness from the sides of the split portion and / or the sides of the shaft. The objective is to provide.

[0014] The ophthalmic surgical instrument according to the present invention makes it easier to distinguish between the sides and other surfaces compared to conventional ophthalmic surgical instruments, and allows for easy identification of the orientation of the ophthalmic surgical instrument during surgery. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 shows a perspective view of the ophthalmic surgical instrument 1 attached to the handle 2, including the front, right side, and top views. [Figure 2]Figure 2 shows a perspective view of the front, right side, and top of the ophthalmic surgical instrument 1. [Figure 3] Figure 3 shows an enlarged right side view of the distal region 10A of the shaft 10. [Figure 4] Figure 4A shows a schematic front view, right side view, and top view of the six cross-sections (reference section CSS and reference section CSR (CSR1 to CSR5)) of the ophthalmic surgical instrument 1. Figure 4B shows a front view of each cross-section shown in Figure 4A. [Figure 5] Figure 5 is a schematic enlarged right side view of the crack 20. [Figure 6] Figure 6 schematically shows the incision range of the ophthalmic surgical instrument 1 according to this embodiment and the conventional ophthalmic surgical instrument 100. [Figure 7] Figure 7A shows a photograph of the distal end of shaft 1, where the entire surface is processed to a glare surface (mirror surface). Figure 7B shows a photograph of the distal end of shaft 1, where the top surface 22, bottom surface 23, front surface 11 and / or rear surface 12 of the shaft are processed to a non-glare surface (matte surface), and the side surface 24 of the split section and the side surface 13 of the shaft are processed to a glare surface (mirror surface). Figure 7C shows a photograph of the distal end of shaft 1, where the top surface 22, bottom surface 23, front surface 11 and / or rear surface 12 of the shaft are processed to a glare surface (mirror surface), and the side surface 24 of the split section and the side surface 13 of the shaft are processed to a non-glare surface (matte surface). Figure 7D shows a photograph of the distal end of shaft 1, where the entire surface is processed to a non-glare surface (matte surface). [Modes for carrying out the invention]

[0016] definition For convenience, the specific terms used in this application are gathered here. Unless otherwise specified, all technical and scientific terms used in this application have the same meaning as those generally understood by those skilled in the art to which this invention pertains. Unless otherwise specified in the context, the singular forms "a," "an," and "the" include plural references.

[0017] The numerical ranges and parameters shown in this invention are approximations, although the numerical values ​​shown in specific examples are described as accurately as possible. However, all numerical values ​​inherently contain certain errors that inevitably arise from the standard deviation observed in each test measurement. Furthermore, the term "about" as used herein generally means within 10%, 5%, 1%, or 0.5% of a given value or range. Alternatively, the term "about" means that it is within an acceptable standard error, as considered by those skilled in the art.

[0018] As used herein, the term "lateral view" means a viewpoint from which the longitudinal shape of the ophthalmic surgical instrument 1, described later, is most clearly displayed, and from which the protruding direction of the slit portion 20, described later, is most clearly displayed, and which includes "right lateral view" and "left lateral view".

[0019] As used herein, the term "front view" means a viewpoint from which the surface of the bottom surface 23 (described later) is most clearly visible, and the surface of the top surface 22 (described later) is not visible, compared to other viewpoints.

[0020] As used herein, the term "distal" means the direction in the longitudinal direction of the ophthalmic surgical instrument 1 in which the slit portion 20 is located, and as used herein, the term "proximal" means the direction opposite to that of "distal".

[0021] As used herein, the term "width" refers to the direction between the sides of the part to which the term applies (the shaft side 13 and the split side 24, described later).

[0022] The embodiments of the present invention will now be described. The following embodiments are illustrative, and the scope of the present invention is not limited to those shown in the following embodiments. In order to avoid repetition and complexity, explanations of similar content will be omitted as appropriate.

[0023] Eye surgery instruments 1 The ophthalmic surgical instrument 1 according to this embodiment is a surgical instrument for splitting fibrous tissue inside the eye. Figure 1 shows a perspective view of the front, right side, and top view of the ophthalmic surgical instrument 1 attached to the handle 2. Since the ophthalmic surgical instrument 1 is sized to be inserted into the eye, it is used by inserting it into a handle 2 that is larger than the instrument 1 for the operator's operability. The longitudinal length of the ophthalmic surgical instrument 1 is approximately 120 mm, but is not limited to this. The width and thickness of the ophthalmic surgical instrument 1 vary depending on the part, but are approximately 0.1 mm to approximately 7 mm (however, are not limited to this range).

[0024] The material of the ophthalmic surgical instrument 1 may be any material widely used for surgical instruments, such as stainless steel. The ophthalmic surgical instrument 1 can be manufactured by processing (for example, cutting) stainless steel wire that has been rolled by a press.

[0025] Figure 2 shows perspective views of the front, right side, and top of the ophthalmic surgical instrument 1. The ophthalmic surgical instrument 1 comprises a long-axis shaft 10 and a split portion 20 that protrudes away from the longitudinal direction of the shaft 10.

[0026] Shaft 10 The shaft 10 in this embodiment is divided into a distal region 10A and a proximal region 10B. The split portion 20 is provided at the distal end of the distal region 10A. The proximal region 10B is longer than the distal region 10A, has a cylindrical shape, and is the region of the shaft 10 that contacts the handle 2. The proximal region 10B preferably has a constant diameter, but may have multiple regions with different diameters. If the proximal region 10B has multiple regions with different diameters, it is preferable that the central axes of each region lie coaxially.

[0027] Figure 3 shows an enlarged right side view of the distal region 10A of the shaft 10. In this embodiment, the distal region 10A of the shaft 10 changes shape from a cylinder to a prism from the proximal to the distal side.

[0028] The distal region 10A of the shaft 10 comprises a shaft front surface 11 located in the direction of projection of the split portion 20, a shaft rear surface 12 located on the opposite side of the projection direction, and a shaft side surface 13 which serves as the connecting surface between the shaft front surface 11 and the shaft rear surface 12. In this embodiment, the thickness of the distal region 10A of the shaft 10 (i.e., the length between the shaft front surface 11 and the shaft rear surface 12) increases towards the proximal direction. In this embodiment, the shaft front surface 11, the shaft rear surface 12, and the shaft side surface 13 are substantially flat.

[0029] In one embodiment, the shaft 10 has a structure without through holes. In another embodiment, the distal region 10A of the shaft 10 does not have through holes. In yet another embodiment, the front surface 11 of the shaft 10 does not have through holes.

[0030] Cleavage part 20 The split portion 20 according to this embodiment includes a tip 21 in which the thickness in the longitudinal direction of the shaft 10 is minimized in the direction of protrusion of the split portion 20, a top surface 22 which is the connection surface between the tip 21 and the front surface 11 of the shaft, a bottom surface 23 which is the connection surface between the tip 21 and the rear surface 13 of the shaft, and a split portion side surface 24 which is the connection surface between the top surface 22 and the bottom surface 23.

[0031] In one embodiment, the top surface 22 is curved so as to be recessed distally in a plan view. In one embodiment, the bottom surface 23 is curved so as to protrude distally in a plan view. In one embodiment, the width of the top surface 22 is constant. In one embodiment, the width of the bottom surface 23 is constant. In one embodiment, the tip 21 is located proximal to the distal end of the ophthalmic surgical instrument 1 in a side view.

[0032] In one embodiment, the width of the tip 21 is the same length as the width of the top surface 22 and / or the bottom surface 23. In another embodiment, the width of the tip 21 may be 95.0 to 99.9% of the width of the top surface 22 and / or the bottom surface 23 (for example, 95.0, 96.0, 97.0, 98.0, 99.0, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8 and 99.9% or a binary range selected from these values).

[0033] Standard cross section CS S Center point P C In the ophthalmic surgical instrument 1 according to this embodiment, in a side view, among the tangents of the surface or point transitioning from the top surface 22 to the front surface 11 of the shaft, the horizontal tangent T that is first parallel to the horizontal axis H extending in the longitudinal direction of the shaft 10 is perpendicular to the horizontal tangent T and the point of contact P between the horizontal tangent T and the top surface 22. T Reference cross section CS passing through S Center point P C The reference cross section CS S Multiple reference sections CS parallel to each other R The horizontal axis H in this embodiment is set back toward the rear surface 13 of the shaft from the first axis A1 that penetrates the center point P that has the most overlap in a front view among the center points P. In this embodiment, the horizontal axis H is an axis parallel to the rear surface 12 of the shaft in a side view, but it is preferable that it be a part that is in the direction in which the ophthalmic surgical instrument 1 is inserted into the eye or a part that is parallel to the direction in which it is inserted.

[0034] In one embodiment, the thickness of the shaft 10 is thinnest at the contact point T. In another embodiment, the thickness of the shaft 10 increases proximal to the contact point T. In another embodiment, the shaft 10 has a region on the proximal side where the thickness and / or width is constant. In yet another embodiment, the shaft 10 has a region on the proximal side where the thickness and / or width is constant, the thickness of the shaft 10 is thinnest at the contact point T, and increases proximal to the contact point T until the thickness of the shaft 10 becomes constant. In yet another embodiment, the width of the shaft 10 is constant. In yet another embodiment, the contact point T is located at the boundary between the top surface 22 and the front surface 11 of the shaft.

[0035] First axis A1 In FIGS. 4A and 4B, the first axis A1 is described in detail. FIG. 4A shows a perspective view displaying the front, right side, and plan views schematically representing six cross-sections (reference cross-section CS S and reference cross-section CS R (CS R1 to CS R5 ) of the ophthalmic surgical instrument 1. FIG. 4B shows a front view of each cross-section shown in FIG. 4A. Each cross-section is parallel to each other, and the area of each cross-section is as follows: CS S <CS R1 <CS R2 <CS R3 =CS R4 =CS R5 . In FIGS. 4A and 4B, the center points P R3 from the reference cross-section CS R5 to P R3 overlap the most in the front view, and the first axis A1 is an axis passing through the center points P R5 from P R3 to P R5 .

[0036] In FIGS. 4A and 4B, five reference cross-sections (CS R1 to CS R5 ) are used for illustration purposes, but it is not limited thereto. In certain embodiments, the plurality of reference cross-sections CS R are selected from the region of the shaft with a constant cross-sectional size. If there is no region of the shaft with a constant cross-sectional size, the axis passing through the center point of the cross-section near the proximal end of the shaft and parallel to the horizontal tangent T can be defined as the first axis A1.

[0037] The first angle α1, the second angle α2, and the tip length L FIG. 5 is a schematic enlarged right side view of the cleavage portion 20. In certain embodiments, The splitting portion 20 may include a first cutting surface 231 between the tip 21 and the bottom surface 23, and a second cutting surface 221 between the tip 21 and the top surface 22. In one embodiment, in a side view, the first angle α1 formed by the first cutting surface 231 and the second cutting surface 221 is between 20 and 50 degrees (for example, 20, 25, 30, 35, 40, 45 and 50 degrees or a binary range selected from these values). In one embodiment, in a side view, the second angle α2 formed by the second axis A2 that bisects the first angle α1 and the horizontal tangent T is between 60 and 100 degrees on the top surface 22 side (for example, 60, 65, 70, 75, 80, 85, 90, 95 and 100 degrees or a binary range selected from these values).

[0038] The tip length L (length of the perpendicular) from the tip 21 of the split portion 20 to the horizontal tangent T may be 0.40 to 0.50 μm (for example, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, and 0.50 μm or a binary range selected from these values). Preferably, the tip length L is 0.43 to 0.47 μm, and more preferably 0.44 to 0.46 μm.

[0039] In one embodiment, contact P T In a plan view, it is located on the shaft rear surface 13 side of the first axis A1. In another embodiment, the first axis A1 is located at the center point P in a plan view. C and contact point P T It is located in between. Point of contact P in plan view. T The distance from to the first axis A1 (length of the perpendicular) may be 0.001 to 0.020 μm, and may be 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, and 0.020 or a binary range selected from these values. Preferably, the distance is 0.005 to 0.015 μm, and more preferably 0.008 to 0.012 μm.

[0040] Incision area Figure 6 schematically shows the incision range of the ophthalmic surgical instrument 1 according to this embodiment and the conventional ophthalmic surgical instrument 100. In the conventional ophthalmic surgical instrument 100, the first axis A1 is the reference cross section CS S Center point P C The structure penetrates through. The tip length L of both the ophthalmic surgical instrument 1 in this embodiment and the conventional ophthalmic surgical instrument 100 is 0.45 μm.

[0041] As shown in Figure 6, the conventional ophthalmic surgical instrument 100 had an insertion angle of 28.08 degrees on one side (56.16 degrees on both sides) in the virtual circle, while the ophthalmic surgical instrument 1 according to this embodiment had an insertion angle of 44.07 degrees on one side (88.14 degrees on both sides) in the virtual circle. The incision range of the ophthalmic surgical instrument 1 according to this embodiment was 1.57 times wider than that of the conventional ophthalmic surgical instrument 100.

[0042] Combination of non-glare and glare surfaces The top surface 22, bottom surface 23, shaft front surface 11 and / or shaft rear surface 12 may have different surface roughness from the cracked portion side surface 24 and / or shaft side surface 13. In one embodiment, the top surface 22, bottom surface 23, shaft front surface 11 and / or shaft rear surface 12 have a non-glare surface, and the cracked portion side surface 24 and / or shaft side surface 13 have a glossy surface. In another embodiment, the top surface 22, bottom surface 23, shaft front surface 11 and / or shaft rear surface 12 have a glossy surface, and the cracked portion side surface 24 and / or shaft side surface 13 have a non-glare surface. The non-glare surface can be formed by sandblasting, and the glossy surface can be protected by a protective material such as masking tape to avoid dulling by sandblasting.

[0043] Figure 7A shows a photograph of the distal end of shaft 1, where the entire surface is processed to a glare surface (mirror surface). Figure 7B shows a photograph of the distal end of shaft 1, where the top surface 22, bottom surface 23, front surface 11 and / or rear surface 12 of the shaft are processed to a non-glare surface (matte surface), and the side surface 24 of the split section and the side surface 13 of the shaft are processed to a glare surface (mirror surface). Figure 7C shows a photograph of the distal end of shaft 1, where the top surface 22, bottom surface 23, front surface 11 and / or rear surface 12 of the shaft are processed to a glare surface (mirror surface), and the side surface 24 of the split section and the side surface 13 of the shaft are processed to a non-glare surface (matte surface). Figure 7D shows a photograph of the distal end of shaft 1, where the entire surface is processed to a non-glare surface (matte surface). In the ophthalmic surgical instrument 1 shown in Figures 7A and 7D, the top surface 22, bottom surface 23, front shaft surface 11, and rear shaft surface 12 have the same surface roughness as the side surface 24 of the opening and the side surface 13 of the shaft. Therefore, there is no difference in contrast between the side surface and the other surfaces, making it difficult to determine the orientation of the ophthalmic surgical instrument 1 during surgery. On the other hand, in the ophthalmic surgical instrument 1 shown in Figures 7B and 7C, the top surface 22, bottom surface 23, front shaft surface 11, and rear shaft surface 12 have different surface roughness from the side surface 24 of the opening and the side surface 13 of the shaft. Therefore, a difference in contrast is created between the side surface and the other surfaces, making it easier to determine the orientation of the ophthalmic surgical instrument 1 during surgery. [Explanation of symbols]

[0044] 1 Ophthalmic surgical instruments 2 handles 10 shafts 11 Shaft front 12 Rear of the shaft 13. Side of the shaft 20 Cleavage 21 Tip 22 Top surface 23 Bottom 24 Side of cleavage part 100 Conventional ophthalmic surgical instruments 231 First blade surface 221 Second blade surface A1 first axis A2 second axis CS R Reference cross section CSS Reference section H horizontal axis P C center point of datum section P R Reference section center point P T contact T-horizontal wiring α1 First Angle α2 second angle

Claims

1. An ophthalmic surgical instrument for cleaving fibrous tissue inside the eye, The aforementioned ophthalmic surgical instruments are, A long, axial shaft, A split portion protruding in a direction away from the longitudinal direction of the shaft Equipped with, The aforementioned shaft is The front surface of the shaft located in the direction of the protruding portion of the split, The rear surface of the shaft located on the opposite side of the aforementioned protruding direction and Equipped with, The aforementioned split portion is The tip of the shaft where the longitudinal thickness is minimized in the direction of the protruding split portion, The top surface which forms the connection surface between the tip and the front surface of the shaft, The bottom surface which serves as the connection surface between the tip and the rear surface of the shaft Equipped with, An ophthalmic surgical instrument characterized in that, in a side view, the center point of a reference cross section that is perpendicular to the horizontal tangent line that first becomes parallel to the horizontal axis extending in the longitudinal direction of the shaft among the tangent lines of the plane or point transitioning from the top surface to the front surface, and that passes through the point of contact between the horizontal tangent line and the top surface, is set back toward the rear surface of the shaft than the first axis that penetrates the center point with the greatest overlap in a front view among the center points of a plurality of reference cross section parallel to the reference cross section.

2. The shaft has a region with a constant thickness on its proximal side. The ophthalmic surgical instrument according to claim 1, wherein the thickness of the shaft is thinnest at the contact point, and the thickness of the shaft increases proximal to a certain region from the contact point.

3. The aforementioned split portion is A first cutting surface is provided between the tip and the bottom surface, A second cutting surface is provided between the tip and the top surface, Furthermore, In a side view, the second angle formed by the second axis that bisects the first angle formed by the first cutting surface and the second cutting surface, and the first axis, is 60 to 100 degrees on the top side, as described in claim 1.

4. An ophthalmic surgical instrument for cleaving fibrous tissue inside the eye, The aforementioned ophthalmic surgical instruments are, A long, axial shaft, A split portion protruding in a direction away from the longitudinal direction of the shaft Equipped with, The aforementioned shaft is The front surface of the shaft located in the direction of the protruding portion of the split, The rear surface of the shaft located on the opposite side of the aforementioned protruding direction, The shaft side surface which is the connecting surface between the front surface of the shaft and the rear surface of the shaft Equipped with, The aforementioned split portion is The tip of the shaft where the longitudinal thickness is minimized in the direction of the protruding split portion, The top surface which forms the connection surface between the tip and the front surface of the shaft, The bottom surface which serves as the connection surface between the tip and the rear surface of the shaft, The side surface of the split portion which is the connecting surface between the top surface and the bottom surface Equipped with, In a side view, among the tangents of the plane or point transitioning from the top surface to the front surface of the shaft, the center point of the reference cross section that is perpendicular to the horizontal tangent that first becomes parallel to the horizontal axis extending in the longitudinal direction of the shaft, and that passes through the point of contact between the horizontal tangent and the top surface, is set back toward the rear surface of the shaft than the first axis that penetrates the center point with the greatest overlap in a front view among the center points of a plurality of reference cross sections parallel to the reference cross section. An ophthalmic surgical instrument characterized in that the top surface, bottom surface, front surface of the shaft and / or rear surface of the shaft have different surface roughness from the side surface of the split portion and / or the side surface of the shaft.

Images