Intraocular lens insertion device

Abstract

To provide an intraocular lens insertion instrument that improves resistance to a load on an insertion portion in a nozzle tip end when an intraocular lens is ejected.SOLUTION: An intraocular lens insertion instrument for inserting an intraocular lens into an eye includes a cylindrical insertion portion 182 which is placed in a distal end of a body portion and is inserted into the eye, and the insertion portion 182 includes stress concentrated areas 185y, 187y where stress generated when the folded intraocular lens passes through the insertion portion 182 is concentrated. The insertion portion includes a thick-walled structure in at least a part in which a thickness dy2 of the stress concentrated areas 185y, 187y of the insertion portion 182 is set to be relatively greater than a thickness dy1 of a site of the insertion portion outside the stress concentrated areas 185y, 187y as the insertion portion 182 is viewed in a direction of a central axis thereof.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to an intraocular lens insertion instrument for inserting an intraocular lens into the eye.

Background Art

[0002] Conventionally, as one of the surgical methods for cataract, a method of inserting a foldable soft intraocular lens into the eye instead of the crystalline lens has been generally used. Also, in order to correct the refractive power of the eye, the intraocular lens may be inserted anterior to the crystalline lens. For the insertion of the intraocular lens into the eye, an intraocular lens insertion instrument called an injector may be used.

[0003] As such an injector, a mode is known in which the intraocular lens is folded small and ejected from the tip by pushing the intraocular lens with an extrusion shaft inside a nozzle having a hollow passage whose passage area through which the intraocular lens passes gradually decreases toward the tip. (See, for example, Patent Document 1). Here, in an injector such as that of Patent Document 1, it is inserted through the incision of the corneal incision. In recent years, in cataract surgery, there has been an increasing trend toward extremely small incisions. That is, in response to the demand for extremely small incision surgery, it is desired to make the insertion part, which is the tip of the injector nozzle, into a thin shape.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, the size of intraocular lenses used as a replacement for the natural lens is generally matched to the size of the eye, and this size is rarely changed significantly. Therefore, if the insertion part, which is the tip of the nozzle, is made thinner to meet the demand for minimizing the incision, the load on the insertion part during intraocular lens ejection tends to increase. In addition, although the hardness of intraocular lenses varies, they generally tend to be harder at lower temperatures due to the properties of polymers.

[0006] Therefore, this disclosure is made to solve the above-mentioned problems and aims to provide an intraocular lens insertion device that improves resistance to load on the insertion part at the nozzle tip during the ejection of the intraocular lens. [Means for solving the problem]

[0007] An intraocular lens insertion device provided by a typical embodiment of the present disclosure is an intraocular lens insertion device that inserts an intraocular lens, which is installed in a cylindrical body, into the eye by pushing it out from the axial rear side to the axial front side of the body with a rod-shaped extrusion member inserted into the body, and also by pushing it out from the tip side of the body in a compact folded state. A cylindrical insertion part is located at the tip of the main body and is inserted into the eye. and, It has a tapered section connected to the axial rear side of the insertion section, which has a hollow passage shape in which the passage area through which the intraocular lens passes gradually decreases toward the tip, The insertion portion has a stress concentration area where stress is concentrated when the folded intraocular lens passes through the insertion portion. The intraocular lens has a disc-shaped optical portion, an anterior support portion that extends radially outward from the outer edge of the optical portion and is located on the axially forward side, which is the insertion portion side, within the tapered portion, and a posterior support portion that is located on the axially rear side, opposite to the insertion portion side. As the intraocular lens is pushed forward in the axial direction by the extrusion member within the tapered portion, the tip portion of the front support portion and the tip portion of the rear support portion are bent toward each other on the optical portion due to the passage shape of the tapered portion, and the lens is folded so as to enclose the front support portion and the rear support portion. The stress concentration area is a region where stress concentrates due to the repulsive force generated in the direction in which the posterior support portion of the folded intraocular lens attempts to restore itself, and includes a region where the base portion of the folded posterior support portion is pressed against the cylindrical inner surface of the insertion portion as the folded intraocular lens passes through the insertion portion. When the insertion portion is viewed from its central axis direction, at least a part of it is configured as a thick-walled structure in which the thickness corresponding to the stress concentration area in the insertion portion is set to be relatively larger than the thickness of the part outside the stress concentration area.

[0008] The intraocular lens insertion device of this disclosure provides an intraocular lens insertion device that improves resistance to load on the insertion portion at the nozzle tip during the ejection of the intraocular lens.

Brief Description of the Drawings

[0009] [Figure 1] It is an overall perspective view showing an intraocular lens insertion instrument. [Figure 2] It is a perspective view showing a plunger. [Figure 3] It is a plan view of an intraocular lens. [Figure 4] It is a right side view of an intraocular lens. [Figure 5] It is a side view showing the installation part and the nozzle of the intraocular lens insertion instrument. [Figure 6] It is a plan view showing the installation part and the nozzle of the intraocular lens insertion instrument. [Figure 7] It is an enlarged view of the insertion part in the nozzle of the intraocular lens insertion instrument. [Figure 8] It is a sectional view taken along line VIII-VIII of FIG. 7. [Figure 9] It is a sectional view taken along line IX-IX of FIG. 7. [Figure 10] It is a sectional view taken along line X-X of FIG. 7. [Figure 11] It is a schematic explanatory view showing a state where an intraocular lens is installed in the installation part. [Figure 12] It is a schematic explanatory view showing a state where extrusion of the intraocular lens by an extrusion member has started. [Figure 13] It is a schematic explanatory view showing a state where the intraocular lens has moved toward the nozzle. [Figure 14] It is a schematic explanatory view showing a state where the intraocular lens has started to enter the nozzle. [Figure 15] It is a schematic explanatory view showing a state where the intraocular lens is deformed within the nozzle. [Figure 16] It is a schematic explanatory view showing a state where the intraocular lens is further deformed within the nozzle. [Figure 17] It is a schematic explanatory view showing a state where the intraocular lens is folded within the nozzle. [Figure 18] It is a partially enlarged view showing the intraocular lens folded within the insertion part.

Mode for Carrying Out the Invention

[0010] <Summary> The intraocular lens insertion instrument exemplified in the present disclosure is an intraocular lens insertion instrument that extrudes an intraocular lens installed in a cylindrical main body portion from the rear side in the axial direction of the main body portion toward the front side in the axial direction with a rod-shaped extrusion member inserted into the main body portion, and extrudes it from the tip side of the main body portion to the outside in a small folded state and inserts it into the eye. A cylindrical insertion portion for inserting into the eye is provided at the tip of the main body portion. The insertion portion has a stress concentration site where stress (for example, stress of the intraocular lens, stress of the rear support portion, stress of the front support portion) generated when the folded intraocular lens passes through the insertion portion is concentrated. When the insertion portion is viewed from its central axis direction, at least a part of the insertion portion is configured with a thick structure in which the thickness corresponding to the stress concentration site in the insertion portion is set to be relatively larger than the thickness of the portion deviating from the stress concentration site. Thereby, it is possible to provide an intraocular lens insertion instrument that improves the resistance to the load on the insertion portion at the nozzle tip during the injection of the intraocular lens.

[0011] Further, the stress concentration site in the insertion portion of the intraocular lens insertion instrument may be a site where stress is concentrated along with the repulsive force (force in the direction of the open posture (restoring posture)) generated in the direction in which the folded intraocular lens tries to restore. Thereby, the resistance to the load can be improved with respect to the site where stress is concentrated along with the repulsive force (force in the direction of the open posture (restoring posture)) generated in the direction in which the folded intraocular lens tries to restore, among the insertion portions at the nozzle tip.

[0012] Furthermore, the intraocular lens insertion device has a tapered section connected to the axial rear side of the insertion section, which has a hollow passage shape in which the area of ​​the passage through which the intraocular lens passes gradually decreases toward the tip. The intraocular lens has a disc-shaped optical section and an anterior support section located on the axial front side, which is the insertion section side, and a posterior support section located on the axial rear side, opposite to the insertion section side, extending radially outward from the outer edge of the optical section. As the intraocular lens is pushed axially forward by the extrusion member within the tapered section, the tip portion of the anterior support section and the tip portion of the posterior support section are bent toward each other toward the optical section due to the passage shape of the tapered section, and the intraocular lens is folded so as to enclose the anterior and posterior support sections. The stress concentration area may be a place where stress is concentrated due to the repulsive force generated in the direction in which the posterior support section of the folded intraocular lens tries to restore itself. Here, as the posterior support portion of the intraocular lens is pushed forward axially by the extrusion member, the area near its base tends to be pressed against the inner surface of the insertion portion as it folds, thus increasing the repulsive force generated in the direction of its restoration. Furthermore, the repulsive force generated in the direction of the posterior support portion's restoration causes the tip of the extrusion member to exert an pushing force in the opposite direction from where the base of the posterior support portion is located, making it easier to load the inner surface of the opposite insertion portion where the posterior support portion is not located. Therefore, by providing a thickened structure at these stress concentration points, the resistance of the nozzle tip to the load on the insertion portion during intraocular lens ejection can be efficiently improved.

[0013] Furthermore, the intraocular lens insertion device described above has an insertion portion in which the opening end face at its tip is inclined with respect to a virtual plane perpendicular to the central axis of the insertion portion, and has an opening tip located at the very front of the inclined opening end face, and a slit cut out axially backward from the end face located at the very rear of the inclined opening end face, and the thickened structure may be configured on at least one of the side surface of the portion that becomes the opening tip of the insertion portion, or the side surface of the portion that becomes the slit of the insertion portion. As a result, the stress concentration area is located on the side surface of the portion that becomes the opening tip of the insertion portion, or the side surface of the portion that becomes the slit of the insertion portion, and by providing a thickened structure on at least one of these areas, the resistance to load on the insertion portion at the nozzle tip during the ejection of the intraocular lens can be selectively improved.

[0014] Furthermore, the thickened structure of the intraocular lens insertion device may be configured on both the side surface of the opening tip portion of the insertion section and the side surface of the slit portion of the insertion section. This further improves the resistance of the nozzle tip to the load on the insertion section during intraocular lens ejection on both the side surface of the opening tip portion of the insertion section and the side surface of the slit portion of the insertion section.

[0015] Furthermore, the thick-walled structure of the intraocular lens insertion device may be configured such that the thickness of the side surface of the opening tip portion of the insertion section differs from the thickness of the side surface of the slit portion of the insertion section. This allows for a more favorable improvement in the load resistance of the insertion section by making the thick-walled structure of the part that is subjected to more load thicker than the side surface of the opening tip portion of the insertion section and the side surface of the slit portion of the insertion section.

[0016] Furthermore, the thick-walled structure of the intraocular lens insertion device described above may be configured such that the thickness of the side surface of the opening tip in the insertion section and the thickness of the side surface of the slit in the insertion section are the same. This allows the thick-walled structure to be configured with the same thickness, thereby suppressing the concentration of stress on one side.

[0017] <Embodiment> Hereinafter, one typical embodiment of this disclosure will be described with reference to Figures 1 to 18.

[0018] In the following explanation, the directions shown in each figure are described as follows: the direction toward the tip of the nozzle 180 side of the main body 100 of the intraocular lens insertion device 10 (lower left side of Figure 1) is described as the front of the intraocular lens insertion device 10, and the direction toward the pressing part 370 of the plunger 300 (upper right side of Figure 1) is described as the rear of the intraocular lens insertion device 10. Furthermore, the upper side of Figure 1 is described as above the intraocular lens insertion device 10, the lower side of Figure 1 is described as below the intraocular lens insertion device 10, the lower right side of Figure 1 is described as the left side of the intraocular lens insertion device 10, and the upper left side of Figure 1 is described as the right side of the intraocular lens insertion device 10.

[0019] <Overall configuration of intraocular lens insertion device 10> Referring to Figure 1, the overall configuration of the intraocular lens insertion device 10 of this embodiment will be described. The intraocular lens insertion device 10 is used to insert a deformable intraocular lens 1 (see Figures 3 and 4; details will be described later) into the eye. The intraocular lens insertion device 10 comprises a main body 100 and a plunger 300. The main body 100 is substantially cylindrical, and the intraocular lens 1 is inserted into the eye through a passage inside the main body 100. The plunger 300 is a rod-shaped member that can move in the front-rear direction (along the extrusion axis A) within the passage inside the main body 100. By moving forward along the extrusion axis (axis of the passage) A, the plunger 300 pushes out the intraocular lens 1 filled inside the main body 100.

[0020] In this embodiment, the main body 100 and plunger 300 of the intraocular lens insertion device 10 are formed by injection molding using a resin material (for example, polypropylene). The intraocular lens insertion device 10 may also be formed by machining by cutting resin. The intraocular lens insertion device 10 may be a cartridge type with a replaceable nozzle 180. Because the intraocular lens insertion device 10 is made of a resin material, the user can easily dispose of the used intraocular lens insertion device 10. In this embodiment, the intraocular lens insertion device 10 is a so-called pre-loaded type, and an example is shown where the intraocular lens 1 is pre-filled and shipped.

[0021] In this embodiment, the inner wall of the main body 100 is treated with a lubricating coating to facilitate the smooth insertion of the adhesive, flexible intraocular lens 1 into the eye. Furthermore, the intraocular lens insertion device 10 in this embodiment is made of a colorless, transparent or colorless, semi-transparent material. Therefore, the user can easily observe the deformation state of the intraocular lens 1 filled inside the intraocular lens insertion device 10 from the outside of the device.

[0022] <Main body 100> Referring to Figure 1, the main body 100 will be described. The main body 100 comprises a main body cylinder 110, an installation section 130, and a nozzle 180, arranged from rear to front.

[0023] The main body cylindrical portion 110 is formed in a cylindrical shape that extends in the front-rear direction. The main body cylindrical portion 110 is located at the rear end of the main body portion 100. A flange portion 111 is provided at the rear end of the main body cylindrical portion 110 in the longitudinal direction, protruding outward from the outer circumferential surface. When in use, the user grips the flange portion 111 by placing their fingers on it.

[0024] The mounting section 130 is connected to the front end of the main body cylindrical section 110. The mounting section 130 has a cylindrical internal structure comprising a mounting section body 134 and a top plate section 132, etc. The mounting section body 134 is a box-shaped member with an open top. The intraocular lens 1, before being pushed out by the plunger 300, is installed (filled) inside the mounting section body 134 in the mounting section 130 (see Figures 11 and 12).

[0025] The top plate portion 132 is positioned across the nozzle 180 and the mounting body 134, and is a cover member that covers their upper openings. The top plate portion 132 may be formed by injection molding using a resin material (for example, polypropylene), cutting by machining the resin, etc. The top plate portion 132 is flat and is formed to cover the openings of the nozzle 180 and the mounting body 134. The top plate portion 132 is provided with a groove-shaped guide portion 140 that guides the plunger 300 along the extrusion direction (extrusion axis A).

[0026] The nozzle 180 is connected to the front end of the mounting section 130, as shown in Figures 5, 6, and 11-17. The nozzle 180 has an insertion section 182 and a tapered section 189.

[0027] The tapered portion 189 has an internal passage area that decreases as it moves forward, causing the intraocular lens 1 to deform as it is pushed forward. In other words, the tapered portion 189 has a hollow passage shape (lumen shape) through which the intraocular lens 1 passes, tapering towards the tip.

[0028] The insertion portion 182 is connected to the front end of the nozzle 180, as shown in Figures 5 to 7. The insertion portion 182 is the part that is inserted (inserted, pierced) into the eye. The insertion portion 182 is cylindrical. The inner surface of the insertion portion 182 has a substantially circular cross-section, and the central axis and the extrusion axis A coincide. The opening end surface at the tip of the insertion portion 182 has an inclined opening end surface 183 (bevel) formed to expel the intraocular lens 1 forward from the internal passage. The inclined opening end surface 183 is provided in the shape of a notch, with its tip cut obliquely, inclined with respect to a virtual plane perpendicular to the central axis (extrusion axis A) of the insertion portion. The internal passage of the main body portion 100 penetrates from the rear end of the main body cylinder portion 110 to the inclined opening end surface 183 at the front end of the nozzle 180. The insertion portion 182 has an opening tip portion 185 located at the very front of the inclined opening end surface 183. Furthermore, the insertion portion 182 has a slit 187 that is cut out in the axial direction rearward from the end face located at the rearmost end of the inclined opening end face 183.

[0029] <Plunger 300> Referring to Figure 2, the schematic configuration of the plunger 300 will be described. The plunger 300 in this embodiment includes an extrusion member 310, a shaft base 350, and a pressing portion 370.

[0030] The pressing portion 370 is formed at the rear end of the plunger 300. The pressing portion 370 is a plate-shaped member that extends in a direction perpendicular to the extrusion shaft A (see Figure 1). The pressing portion 370 is the part that the user's fingers come into contact with when the user pushes the plunger 300 forward.

[0031] The shaft base 350 is a rod-shaped member extending forward from the front end of the pressing portion 370. In this embodiment, the shaft base 350 is formed such that the cross-sectional shape perpendicular to the extrusion shaft A is approximately H-shaped. The shaft base 350 is inserted into the main body cylindrical portion 110, which has a cross-sectional shape perpendicular to the extrusion shaft A, thereby suppressing the circumferential rotation of the plunger 300 relative to the main body portion 100 on the extrusion shaft A. When the plunger 300 moves forward and reaches the position where the insertion of the intraocular lens 1 into the eye is completed, the inclined surface at the lower front end of the shaft base 350 contacts and stops an inclined surface formed at a predetermined location on the main body portion 100. As a result, the front end of the plunger 300 is prevented from protruding excessively from the inclined opening end face 183 (see Figure 1).

[0032] The extrusion member 310 is a rod-shaped member that extends forward from the front end of the shaft base 350 along the axial direction of the extrusion shaft A. The extrusion member 310 is formed such that the cross-sectional shape perpendicular to the extrusion shaft A is substantially circular. The thickness of the extrusion member 310 is such that it can pass through the inclined opening end face 183 of the main body 100. The extrusion member 310 moves forward along the extrusion shaft A within the passage of the main body 100, thereby tucking the intraocular lens 1 and ejecting the intraocular lens 1 into the eye through the inclined opening end face 183.

[0033] <Intraocular lens> Referring to Figures 3 and 4, an example of an intraocular lens 1 inserted into the eye by an intraocular lens insertion device 10 will be described. The intraocular lens 1 comprises an optical part 2 and a support part 3. The intraocular lens 1 of this embodiment is a so-called one-piece type intraocular lens in which the optical part 2 and the support part 3 are integrally molded. In the intraocular lens 1 used in this embodiment, the optical part 2 and a pair of support parts 3, namely an anterior support part 3A and a posterior support part 3B, are integrally molded. As the material of the flexible material, the intraocular lens 1 can be made of various flexible resin materials, such as BA (butyl acrylate), HEMA (hydroxyethyl methacrylate), or composite materials of acrylic acid ester and methacrylic acid ester. Although a so-called one-piece type intraocular lens 1 is exemplified in this embodiment, at least a part of the technology exemplified in this disclosure can also be applied to a so-called three-piece type intraocular lens in which the optical part 2 and the support part 3 are formed from separate components.

[0034] The optical unit 2 provides a predetermined refractive power to the patient's eye. The optical unit 2 is disc-shaped. The optical axis L of the optical unit 2 passes through the center of the optical unit 2 and extends in the vertical direction. The optical unit 2 has a first surface 2A as an end face in the direction of the optical axis L, which contacts the top plate portion 132 of the mounting portion 130 as described later, and a second surface 2B formed on the opposite side of the first surface 2A. The support portion 3 supports the optical unit 2 within the eye. As an example, the intraocular lens 1 of this embodiment is provided with a pair of support portions 3, namely an anterior support portion 3A and a posterior support portion 3B. The anterior support portion 3A and the posterior support portion 3B extend radially outward from the outer peripheral edge portion 2C of the optical unit 2 and are formed in point-symmetric positions with respect to the optical axis L, which is the center of the optical unit 2. The front support portion 3A has a base portion 6A connected to the outer peripheral edge 2C of the optical portion 2 via a connecting portion 4A, and is a loop shape curved in the circumferential direction, with an open tip portion 8A (i.e., the tip portion 8A is a free end). The rear support portion 3B has a base portion 6B connected to the outer peripheral edge 2C of the optical portion 2 via a connecting portion 4B, and is a loop shape curved in the circumferential direction, with an open tip portion 8B (i.e., the tip portion 8B is a free end). The front support portion 3A is located within the main body portion 100 on the side of the inclined opening end face 183 relative to the optical portion 2. The rear support portion 3B is located within the main body portion 100 on the rear side of the optical portion 2 (the side away from the inclined opening end face 183).

[0035] <Thick-walled structure of insertion section 182> Here, the intraocular lens implantation device has a narrow insertion section 182. Therefore, the insertion section 182 is prone to stress concentration at stress concentration points where stress is concentrated as the folded intraocular lens 1 passes through the insertion section 182. These stresses include stress on the folded intraocular lens 1 and stress associated with the repulsive force that occurs in the direction in which the folded intraocular lens 1 tries to unfold. Therefore, in order to improve resistance to the load during ejection of the intraocular lens 1, the insertion section 182 is configured with a thick-walled structure in which the thickness corresponding to the stress concentration point in the insertion section 182 is set to be relatively larger than the thickness of the part outside the stress concentration point when viewed from the direction of the central axis (extrusion axis A) (in other words, when viewed from the direction along the central axis (extrusion axis A) of the insertion section 182). This thick-walled structure may be locally thickened at the stress concentration point, or it may be a structure in which the thickness is gradually increased between the part outside the stress concentration point and the stress concentration point.

[0036] The thickness of the inclined open end face 183 of the insertion portion 182 does not consist of a thick-walled structure but has a uniform thickness structure. This is because, as the folded intraocular lens 1 is ejected from the inclined open end face 183, it begins to unfold into an open position (restoration position), and the stress generated as the intraocular lens 1 passes through the insertion portion 182 gradually decreases. Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 7. As shown in Figure 8, the thickness of the inclined open end face 183 of the insertion portion 182 (cross-section viewed from the central axis (extrusion axis A)) consists of a uniform thickness dx. Thus, the thickness of each cross-section of the inclined open end face 183 of the insertion portion 182 is the same.

[0037] The locations where the thick-walled structure is formed in the insertion portion 182 will now be explained. The thick-walled structure in the insertion portion 182 is formed in both the "side surface of the portion that becomes the opening tip 185" and the "side surface of the portion that becomes the slit 187" in a cross-section viewed from the direction of the central axis (extrusion axis A) (in other words, a cross-section viewed from a direction along the central axis (extrusion axis A) of the insertion portion 182). Furthermore, the aforementioned thick-walled structure on the side surface is formed continuously along the rear side of the inclined opening end face 183 (in other words, the cylindrical portion of the insertion portion 182). That is, a stress concentration area occurs in the cylindrical inner surface portion of the inner surface of the insertion portion 182 that is rear of the inclined opening end face 183.

[0038] In this case, the folded intraocular lens 1 has a filling rate of 150% to 200% compared to the volume of the lumen of the insertion portion 182, thus increasing the internal pressure associated with the intraocular lens 1. Here, the thickness of the center of the optical portion 2 of the intraocular lens 1 tends to increase with increasing power. Therefore, the internal pressure tends to increase, especially in the case of a high-power (thick) intraocular lens 1. Due to this internal pressure, when the intraocular lens 1 passes through the insertion portion 182, a stress concentration area is created on the inner surface of the cylindrical part of the insertion portion 182 that is posterior to the inclined opening end face 183.

[0039] Furthermore, there are also cases where stress concentrates due to the repulsive force generated in the direction in which the folded intraocular lens 1 attempts to restore itself. Here, as the posterior support portion 3B of the intraocular lens 1, which is pushed forward in the axial direction by the extrusion member 310, is folded, the vicinity of its base portion 6B tends to be pressed against the inner surface of the insertion portion 182, so the repulsive force generated in the direction in which it attempts to restore itself tends to increase in that area. Here, since the posterior support portion 3B of the folded intraocular lens 1 passes near the "side surface of the portion that becomes the slit 187", a thickened structure is formed in that area.

[0040] Also, due to the repulsive force generated in the direction in which the rear support portion 3B attempts to recover, an extrusion force acts on the tip of the extrusion member 310 in the opposite direction to the direction where the root portion 6B of the rear support portion 3B is not disposed, making it easier for a partial load to be applied to the inner surface of the insertion portion 182 on the opposite side where the rear support portion 3B is not disposed. Therefore, the "side surface of the portion that becomes the slit 187" has a thick structure formed at the "side surface of the portion that becomes the opening tip portion 185" at a point-symmetrical position.

[0041] The stress concentration site generated in the insertion portion 182 is a cylindrical portion on the rear side of the inclined opening end face 183, and is the "side surface of the portion that becomes the opening tip portion 185 (185y in FIG. 9, 185z in FIG. 10)" and the "side surface of the portion that becomes the slit 187 (187y in FIG. 9, 187z in FIG. 10)".

[0042] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 7. Such a portion is a cross-section at the position of the slit bottom portion 188 of the slit 187. Here, stress concentration sites 185y and 187y are present in such a cross-section. The stress concentration sites 185y and 187y are sites where stress concentrates along with the repulsive force generated in the direction in which the folded intraocular lens 1 attempts to recover. The stress concentration sites 185y and 187y are configured at point-symmetrical positions around the extrusion axis A (central axis). The stress concentration site 185y is configured at the side surface portion of the portion that becomes the opening tip portion 185 in the insertion portion 182. The stress concentration site 187y is configured at the side surface portion of the portion that becomes the slit 187 in the insertion portion 182. Both the stress concentration site 185y and the stress concentration site 187y have a thickness dy2. On the other hand, the thickness dy1 of the portion deviating from the stress concentration site 185y and the stress concentration site 187y is set to be thinner than the thickness dy2 (dy1 < dy2). Here, the thickness dy2 corresponding to the stress concentration sites 185y and 187y is taken as the maximum thickness in such a cross-section, and the thickness gradually decreases from the thickness dy2 to the thickness dy1 (smoothly connected from the thickness dy2 to the thickness dy1 in a surface shape). Also, the inner surface of the insertion portion 182 is circular. Therefore, the stress concentration sites 185y and 187y have an increased thickness on the radially outer side.

[0043] FIG. 10 is a cross-sectional view taken along the line X-X in FIG. 7. Such a portion is a cross-section at a position behind the slit bottom 188 of the slit 187. Here, stress concentration sites 185z and 187z are present in such a cross-section. The stress concentration sites 185z and 187z are sites where stress is concentrated along with the repulsive force generated in the direction in which the folded intraocular lens 1 tries to recover. The stress concentration sites 185z and 187z are configured at positions that are point-symmetric about the extrusion axis A (central axis). The stress concentration site 185z is configured at a side surface site of the portion that becomes the opening tip 185 in the insertion portion 182. The stress concentration site 187z is configured at a side surface site of the portion that becomes the slit 187 in the insertion portion 182. Both the stress concentration site 185z and the stress concentration site 187z have a thickness dz2. On the other hand, the thickness dz1 of the portion deviating from the stress concentration site 185z and the stress concentration site 187z is set to be thinner than the thickness dz2 (dz1 < dz2). Here, the thickness dz2 corresponding to the stress concentration sites 185z and 187z is taken as the maximum thickness in such a cross-section, and the thickness gradually decreases from such a thickness dz2 to the thickness dz1 (smoothly connected in a surface shape from the thickness dz2 to the thickness dz1). Also, the inner surface of the cylinder of the insertion portion 182 is circular. Therefore, the stress concentration sites 185z and 187z have thickened outer sides in the radial direction.

[0044] Note that the thick structure in the insertion portion 182 may be at least one of "the side surface of the portion that becomes the opening tip 185" and "the side surface of the portion that becomes the slit 187". Also, the thick structure in the insertion portion 182 may be a part behind the inclined opening end surface 183. Also, the stress concentration site 185y and the stress concentration site 187y are configured with the same thickness dy2, but they may be configured with different thicknesses. Also, the stress concentration site 185z and the stress concentration site 187z are configured with the same thickness dz2, but they may be configured with different thicknesses.

[0045] Referring to FIGS. 11 to 18, the effects of adopting the technology exemplified in this embodiment will be described. First, the operator moves the intraocular lens 1 held by the installation portion 130 to a standby position where it can be pushed out by the plunger 300.

[0046] As shown in Figure 11, the intraocular lens 1 installed in the mounting section 130 has the base portion 6A of the anterior support section 3A positioned to the right (upper side in Figure 11) relative to the extrusion shaft A, and the base portion 6B of the posterior support section 3B positioned to the left (lower side in Figure 11) relative to the extrusion shaft A. The intraocular lens insertion device 10 in this embodiment is a so-called preset type device in which the intraocular lens 1 is pre-filled inside. However, the technology illustrated in this disclosure can also be applied to intraocular lens insertion devices in which the intraocular lens 1 is filled inside immediately before insertion into the patient's eye.

[0047] The worker uses an injector or the like to inject a filler (e.g., viscoelastic material, water, etc.) into the installation section 130 and starts the forward movement of the plunger 300. As a result, as shown in Figure 11, the extrusion member 310 of the plunger 300 comes into contact with a part of the posterior support section 3B of the intraocular lens 1.

[0048] As shown in Figure 12, as the plunger 300 is pushed further forward, the rear support portion 3B moves towards the optical unit 2 (i.e., forward) by the extrusion member 310. Subsequently, the rear support portion 3B deforms and folds onto the first surface 2A of the optical unit 2 (towards the viewer in Figure 12), and the tip portion 8B of the rear support portion 3B faces forward. As a result, the rear support portion 3B is tucked.

[0049] As shown in Figure 13, as the plunger 300 is pushed further forward, the intraocular lens 1 reaches the nozzle 180 and enters the inner wall of the tapered portion 189. The anterior support portion 3A is located axially forward of the optical portion 2, on the insertion portion 182 side. The posterior support portion 3B is located axially backward of the optical portion 2, opposite to the insertion portion 182 side.

[0050] As shown in Figure 14, the plunger 300 is pushed further forward. Then, the optical portion 2 of the intraocular lens 1 begins to deform in a roll shape along the inner wall of the tapered portion 189, as the inner wall of the tapered portion 189 is curved.

[0051] As shown in Figure 15, as the plunger 300 is pushed further forward, the intraocular lens 1 deforms further into a roll shape along the inner wall of the nozzle 180.

[0052] As shown in Figure 16, as the plunger 300 is pushed further forward, the intraocular lens 1 deforms further into a roll shape along the inner wall of the nozzle 180. The front support portion 3A remains on the inner wall of the tapered portion 189 and approaches the optical portion 2 that has been pushed out by the extrusion member 310. Subsequently, the front support portion 3A deforms and moves toward the first surface 2A of the optical portion 2 (towards the viewer in Figure 16) and folds, and the tip portion 8A of the front support portion 3A faces backward. As a result, tacking of the front support portion 3A occurs.

[0053] As shown in Figure 17, as the plunger 300 is pushed further forward, the intraocular lens 1 folds into a smaller size with the anterior support portion 3A and the posterior support portion 3B tucked together.

[0054] As shown in Figures 17 and 18, as the intraocular lens 1 is pushed forward in the axial direction by the extrusion member 310 within the tapered portion 189, the tip portion 8A of the front support portion 3A and the tip portion 8B of the rear support portion 3B are bent onto the optical portion 2 in a direction that brings them closer to each other due to the passage shape of the tapered portion 189, and the lens is folded to enclose the front support portion 3A and the rear support portion 3B.

[0055] Here, as the posterior support portion 3B of the intraocular lens 1, which is pushed forward in the axial direction by the extrusion member 310, is folded, the vicinity of its base portion 6B tends to be pressed against the inner surface of the insertion portion 182, so the repulsive force generated in the direction of restoration tends to increase partially on the inner surface in which it is applied. Here, the posterior support portion 3B of the folded intraocular lens 1 passes near the "side surface of the portion that becomes the slit 187 (187y in Figure 9, 187z in Figure 10)", so a thickened structure is formed in that area.

[0056] Further, due to the repulsive force generated in the direction in which the rear support portion 3B attempts to recover, an extrusion force acts in the direction opposite to the direction in which the root portion 6B of the rear support portion 3B is not disposed at the tip of the extrusion member 310, making it easier for a partial load to be applied to the inner surface of the insertion portion 182 opposite to the side where the rear support portion 3B is not disposed. Therefore, the "side surface of the portion that becomes the slit 187" has a thick structure formed at the "side surface of the portion that becomes the opening tip 185 (185y in FIG. 9, 185z in FIG. 10)" at the point-symmetric position.

[0057] The stress concentration site occurring in the insertion portion 182 is a cylindrical portion on the rear side of the inclined opening end surface 183, and is the "side surface of the portion that becomes the opening tip 185 (185y in FIG. 9, 185z in FIG. 10)" and the "side surface of the portion that becomes the slit 187 (187y in FIG. 9, 187z in FIG. 10)". By setting the thickness of such portions as dy2 and dz2, they are made thicker than the thicknesses dy1 and dz1 of the portions deviating from the stress concentration site (dz1 < dz2). Therefore, due to such a thick structure, the resistance to the load on the insertion portion 182 at the nozzle tip during the injection of the intraocular lens 1 can be efficiently improved.

[0058] Thereafter, the intraocular lens 1 is inserted into the eye from the inclined opening end surface 183. Here, when the intraocular lens insertion instrument 10 inserts the insertion portion 182 into the capsular bag of the lens, it inserts the opening of the inclined opening end surface 183 in a posture facing the posterior capsule of the lens. When the intraocular lens 1 is sent out from the inclined opening end surface 183, it is sent out in the following behavior. Immediately before the intraocular lens 1 is sent out from the inclined opening end surface 183, the tacked rear support portion 3B is sandwiched between the extrusion member 310 and the inner wall of the nozzle 180, and at the same time, the optical portion 2 starts to unfold into an open posture (recovery posture) while rotating around the axis of the extrusion axis A. Then, when the rear support portion 3B is finally sent out from the inclined opening end surface 183, the intraocular lens 1 is placed in the lens in a posture where the first surface 2A faces the anterior capsule and the second surface 2B faces the posterior capsule.

[0059] Thus, according to the intraocular lens insertion device of the embodiment of this disclosure, resistance to load on the insertion portion 182 at the nozzle tip during the ejection of the intraocular lens 1 can be improved.

[0060] Furthermore, in the insertion portion 182 at the tip of the nozzle, the load resistance can be improved in areas where stress concentrates due to the repulsive force (force in the direction of the open position (restoration position)) generated in the direction in which the folded intraocular lens 1 tries to restore itself.

[0061] Furthermore, as the posterior support portion 3B of the intraocular lens 1, which is pushed forward in the axial direction by the extrusion member, folds, the area near its base portion 6B tends to be pressed against the inner surface of the insertion portion 182, thus increasing the repulsive force generated in the direction of its attempt to restore itself. In addition, the repulsive force generated in the direction of the posterior support portion 3B attempting to restore itself causes the tip of the extrusion member to exert an pushing force in the opposite direction from where the base portion 6B of the posterior support portion 3B is located, making it easier to load the inner surface of the opposite insertion portion 182 where the posterior support portion 3B is located. Therefore, by providing a thickened structure at these stress concentration points 185y, 185z, 187y, and 187z, the resistance of the nozzle tip to the load on the insertion portion 182 during the ejection of the intraocular lens 1 can be efficiently improved.

[0062] Furthermore, since the stress concentration points 185y, 185z, 187y, and 187z are located on the side surface of the portion that becomes the opening tip 185 of the insertion portion 182, or on the side surface of the portion that becomes the slit 187 of the insertion portion 182, providing a thickened structure to at least one of these portions makes it possible to selectively improve the resistance of the nozzle tip to the load on the insertion portion 182 when the intraocular lens 1 is ejected.

[0063] Furthermore, by providing a thickened structure on both the side surface of the opening tip 185 of the insertion portion 182 and the side surface of the slit 187 of the insertion portion 182, the resistance to the load on the insertion portion 182 at the nozzle tip during the ejection of the intraocular lens 1 can be further improved.

[0064] Furthermore, by making the thicker wall structure of the side surface of the opening tip 185 of the insertion portion 182 and the side surface of the slit 187 of the insertion portion 182 thicker in the areas that are subjected to more load, the load resistance of the insertion portion 182 can be suitably improved. In addition, by having the thicker wall structure be made of the same thickness, it is possible to suppress the uneven distribution of stress concentration in one area.

[0065] Although embodiments of the present disclosure have been described above, the intraocular lens implantation device of the present disclosure is not limited to the above embodiments and can be implemented in various other forms. For example, although the thickened structure is shown to be made of the same resin material, it is not limited to this and the thickened portion may be made of a resin with higher strength (e.g., two-color molding). Alternatively, the thickened portion may be made of a different material with higher strength. [Explanation of Symbols]

[0066] 1. Intraocular lens 2 Optical Department 2A 1st page 2B 2nd side 2C Outer edge 3 Support part 3A Front support part 4A Connection part 6A Root part 8A tip part 3B Rear support part 4B Connection section 6B Root part 8B Tip part 10. Intraocular lens insertion device 100 Main body 110 Main body cylindrical part 111 Tsuba (guard) 130 Installation section 132 Top panel 134 Installation Unit 140 Information Department 180 nozzles 182 Insertion section 183 Slanted opening end face 185 Opening tip 185y Stress concentration area 185z stress concentration area 187 Slit 187y Stress concentration area 187z stress concentration area 188 Slit bottom 189 Tapered section 300 plungers 310 Extruded member 350 shaft base 370 Pressing part A. Extrusion shaft (central axis) L optical axis dy1 Thickness dy2 thickness dz1 thickness dz2 thickness

Claims

1. An intraocular lens insertion device is used to insert an intraocular lens, which is installed in a cylindrical main body, into the eye by pushing it out from the axial rear side to the axial front side of the main body using a rod-shaped extrusion member inserted into the main body, and also by pushing it out from the tip side of the main body in a compact folded state. A cylindrical insertion part is provided at the tip of the main body and inserted into the eye, It has a tapered section connected to the axial rear side of the insertion section, which has a hollow passage shape in which the passage area through which the intraocular lens passes gradually decreases toward the tip, The insertion portion has a stress concentration area where stress is concentrated when the folded intraocular lens passes through the insertion portion. The intraocular lens has a disc-shaped optical portion, an anterior support portion that extends radially outward from the outer edge of the optical portion and is located on the axially forward side, which is the insertion portion side, within the tapered portion, and a posterior support portion that is located on the axially rear side, opposite to the insertion portion side. As the intraocular lens is pushed forward in the axial direction by the extrusion member within the tapered portion, the tip portion of the front support portion and the tip portion of the rear support portion are bent toward each other on the optical portion due to the passage shape of the tapered portion, and the lens is folded so as to enclose the front support portion and the rear support portion. The stress concentration area is a region where stress concentrates due to the repulsive force generated in the direction in which the posterior support portion of the folded intraocular lens attempts to restore itself, and includes a region where the base portion of the folded posterior support portion is pressed against the cylindrical inner surface of the insertion portion as the folded intraocular lens passes through the insertion portion. An intraocular lens insertion device comprising, at least a portion of the insertion portion having a thick-walled structure in which, when viewed from the central axis direction, the thickness corresponding to the stress concentration area in the insertion portion is set to be relatively larger than the thickness of the area outside the stress concentration area.

2. An intraocular lens insertion device according to claim 1, The aforementioned insertion portion has an inclined opening end surface at its tip that is inclined with respect to a virtual plane perpendicular to the central axis of the insertion portion. The opening tip located at the very front of the inclined opening end face, The inclined opening end face has a slit cut out in the axial direction rearward from the end face located at the rearmost end, The thickened structure is an intraocular lens insertion device that is configured at least on the side surface of the cylindrical part of the insertion portion that is located behind the inclined opening end face and forms the slit.

3. An intraocular lens insertion device according to Claim 2, The thickened structure is further configured on the side surface of the opening tip portion of the insertion portion, which is a cylindrical part located behind the inclined opening end face and is point-symmetric to the side surface of the slit portion.

4. An intraocular lens insertion device according to Claim 3, The thick-walled structure is configured such that the thickness of the side surface of the portion that becomes the opening tip in the insertion portion is different from the thickness of the side surface of the portion that becomes the slit in the insertion portion.

5. An intraocular lens insertion device according to Claim 3, The thick-walled structure is an intraocular lens insertion device in which the thickness of the side surface of the portion that becomes the opening tip of the insertion portion and the thickness of the side surface of the portion that becomes the slit of the insertion portion are the same.

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