WO2007097221A1

WO2007097221A1 - Intraocular lens inserter

Info

Publication number: WO2007097221A1
Application number: PCT/JP2007/052460
Authority: WO
Inventors: Takashi Ichinohe
Original assignee: Hoya Corporation
Priority date: 2006-02-22
Filing date: 2007-02-13
Publication date: 2007-08-30
Also published as: JP4947484B2; JP2007222309A

Abstract

An intraocular lens inserter with which a lens can be inserted into an eyeball surely in safety by pushing a plunger gently even by a single hand operation. The intraocular lens inserter (1) comprises a tubular body (3) for passing a deformable intraocular lens (2) and introducing it into an eyeball, a plunger (4) contained reciprocatingly in the body (3) and pressing the intraocular lens (2) to be released into the eyeball, and a resilient body (5) and/or a sliding resistance increasing mechanism provided between the body (3) and the plunger (4). Pressing force (F) of the plunger (4) can be kept at 60% or above of a first peak value in the moving stroke (X) of the plunger (4) after the first peak value is reached.

Description

Specification

Intraocular lens insertion device

Technical field

[0001] The present invention relates to an intraocular lens insertion device for inserting an intraocular lens into an eyeball instead of a crystalline lens removed by cataract surgery.

Background art

In cataract surgery, a method is widely used in which a turbid lens is removed by ultrasonic emulsification and the artificial intraocular lens is implanted in the eye after the lens is removed. The implanted intraocular lens has a hard intraocular lens whose optical part is made of a hard material such as polymethylmethallate (PMMA), and a soft material that is made of a soft material such as silicone elastomer, soft acrylic, and hyde mouth gel. There is an intraocular lens. When using a rigid intraocular lens, it is necessary to insert the intraocular lens into the cornea or sclera through an incision with a width approximately the same as or slightly larger than the diameter of the optical part. On the other hand, when a soft intraocular lens is used, the intraocular lens can be inserted into the eyeball from a smaller incision by folding the optical part. By performing surgery with a small incision, the risk of corneal astigmatism after surgery can be avoided. Powerful circumstances In recent years, soft intraocular lenses have been favored.

[0003] A method for inserting a soft intraocular lens into an eye is called an injector, in addition to a method for directly inserting an intraocular lens (hereinafter simply referred to as a lens) folded by an insulator directly into the eye. There is a method using a dedicated intraocular lens insertion device. In general, the basic structure of an injector consists of a nozzle portion that is tapered to insert the lens into the eye, a plunger that pushes out the lens, and a cylindrical body that holds them. Various types of intraocular lens insertion devices have been proposed. They are roughly classified into two-handed and one-handed.

[0004] A double-handed intraocular lens insertion instrument is one in which an intraocular lens is inserted into an eyeball by holding a body of the insertion instrument with one hand and pushing a plunger with the other hand. Specifically, a female screw and a screw provided in a part of the main body at the rear end of the plunger. A matching male screw is provided, and the rear end of the plunger is rotated to move the plunger back and forth to push out the lens.

[0005] In addition, the one-hand operated intraocular lens insertion instrument is configured such that the index finger and the middle finger of one hand are brought into contact with a gripping piece provided in the insertion instrument body, and the thumb is brought into contact with the end face of the plunger and pressed. The lens is inserted into the eyeball. One-hand operated intraocular lens insertion instruments can be operated with only one hand, and have the advantages of using the other hand to grasp and stabilize eye tissue with tweezers, or to operate other surgical instruments. One tends to prefer single-handed intraocular lens insertion instruments. By using such a dedicated indicator, it is possible to fold the lens smaller than using a lever, and an incisional loci of 3 mm or less can be inserted into the eye.

[0006] However, a one-hand operated intraocular lens insertion device presses a lens with a plunger housed in a cylindrical body so as to be reciprocally movable, and releases it into the eye. The pressing force varies greatly depending on the sliding resistance between the lens and the inner surface of the main body. In addition, the sliding resistance between the lens and the inner surface of the main body is large, and it becomes difficult to control the pushing force when the folded lens is released at the tip of the main body, which is a nozzle. Risk damaging the intraocular tissue. Therefore, an injector having a structure that can gently push the plunger in any situation has been desired.

[0007] Under such circumstances, in order to reduce the sliding resistance between the lens and the inner surface of the main body, there is one in which the inner surface of the main body is coated. This injector certainly reduces the change in sliding resistance when the lens is opened, so the risk of sudden popping out of the lens and plunger is low.

[0008] Further, a rubber O-ring is disposed between the outer peripheral surface of the plunger and the inner peripheral surface of the main body, and a certain pressing force is applied to the side surface of the plunger to reduce the sliding resistance. Technology to change is disclosed. However, in the case where the O-ring is arranged in this way, the number of parts increases, so that the manufacturing cost becomes expensive. In addition, the size of the sliding resistance varies depending on the individual due to the manufacturing dimension error of the O-ring body (see, for example, Patent Document 1). [0009] Further, in order to prevent a sudden jump-out of the lens and the plunger when the lens is released, a panel is interposed between the main body and the plunger so that a load in the opposite direction is applied to the plunger. Have been disclosed. (For example, see Patent Document 2).

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-113610

Patent Document 2: Japanese Translation of Special Publication 2000-516487

Disclosure of the invention

Problems to be solved by the invention

[0010] In a one-hand operation type intraocular lens insertion device in which a panel is interposed between the main body and the plunger to apply a load in the opposite direction, the panel constant and the panel deformation It is extremely important to adjust the amount optimally. When the strength of the panel is insufficient, when the lens is released into the eye, the lens may jump out from the tip of the nozzle and damage the intraocular tissue. On the other hand, if the strength of the panel is too great, the force required to push out the lens also increases, making it difficult to operate with one hand. Therefore, if the strength and deformation of the panel do not match the sliding resistance between the plunger and the main body and the pressing force of the plunger required to deform the lens, the intended purpose is achieved. I can't.

[0011] The present invention is intended to solve such a problem of the conventional technology, and can insert the lens into the eyeball safely and securely by pushing the plunger gently with only one hand operation. It is an object to provide an instrument.

Means for solving the problem

[0012] The invention according to claim 1 includes a cylindrical main body that passes through a deformable intraocular lens and guides it into the eyeball, and is reciprocally moved in the main body. The eyeball is pressed by pressing the intraocular lens. An intraocular lens insertion device comprising a plunger that is released into the body, and an elastic body and Z or a sliding resistance increasing mechanism between the main body and the plunger, and the pressing force (F) force of the plunger In the movement stroke (X) of the plunger after reaching the first peak value, 60% or more of the peak value can be maintained.

[0013] The invention according to claim 2 includes a cylindrical main body that passes through a deformable intraocular lens and guides it into the eyeball, and is reciprocally moved in the main body, and presses the intraocular lens to press the eyeball. A plunger that releases into the body, and an elastic body and Z or between the main body and the plunger. An intraocular lens insertion device provided with a sliding resistance increasing mechanism, wherein the value of the plunger pressing force (F) with respect to the movement stroke (X) of the plunger does not decrease It is.

[0014] The invention according to claim 3 is the intraocular lens insertion device according to claim 1 or 2, characterized in that the elastic body includes a plurality of elastic bodies having different elasticity values. is there

[0015] The invention according to claim 4 is the intraocular lens insertion device according to claim 1 or 2, characterized in that the elastic value of the elastic body has a nonlinear characteristic.

The invention's effect

[0016] According to the intraocular lens insertion device of claim 1, since the pressing force of the plunger with respect to the movement stroke of the plunger does not significantly decrease even after the first peak has elapsed, Can also move the plunger gently. Therefore, the lens can be safely and reliably inserted into the eyeball.

[0017] According to the intraocular lens insertion device of claim 2, since the value of the plunger pressing force with respect to the movement stroke of the plunger does not decrease, the plunger can be loosened even with one-handed operation. Can be moved. Therefore, the lens can be inserted into the eyeball safely and reliably.

[0018] According to the intraocular lens insertion device of claim 3, the panel reaction force with respect to the movement stroke of the plunger can be made to have a discontinuous characteristic by combining a plurality of elastic bodies having different elastic values. As a result, the maximum value of the plunger pressing force can be suppressed.

[0019] According to the intraocular lens insertion device of claim 4, since the elastic value of the elastic body has nonlinear characteristics, the panel reaction force with respect to the movement stroke of the plunger can be designed more precisely.

Brief Description of Drawings

FIG. 1 is a cross-sectional view of an intraocular lens insertion device showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the plunger stroke and the pressing force of an intraocular lens insertion device without an elastic body. FIG. 3 is a characteristic diagram showing the relationship between the plunger travel and the pressing force when a lens is not loaded into an intraocular lens insertion device provided with an elastic body.

FIG. 4 is a characteristic diagram showing the relationship between the plunger travel and the pressing force in the intraocular lens insertion device of the first embodiment.

FIG. 5 is a characteristic diagram showing the relationship between the plunger travel and the pressing force when elastic bodies having different elasticity values are used.

[Figure 6] Same as above

[Figure 7] Same as above

FIG. 8 is a cross-sectional view of an intraocular lens insertion device showing a second embodiment of the present invention.

FIG. 9 is a characteristic diagram showing the relationship between the travel of the plunger and the pressing force when the intraocular lens insertion device of the second embodiment is not loaded with a lens.

FIG. 10 is a cross-sectional view of an intraocular lens insertion device showing a third embodiment of the present invention.

FIG. 11 is a cross-sectional view of an intraocular lens insertion device showing a fourth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of an intraocular lens insertion device to which the present invention is applied. The intraocular lens insertion device 1 is housed in a cylindrical main body 3 that passes through a deformable intraocular lens 2 and is guided into the eyeball, and is reciprocally moved in the main body 3, and presses the intraocular lens 2. A plunger 4 that is released into the eyeball, and an elastic body 5 between the main body 3 and the plunger 4.

[0022] The cylindrical main body 3 includes a nozzle 3a in which the tip of the incisional locus of the eyeball is inserted into the eyeball, a lens installation portion 3b in which the lens 2 is installed, and a gripping portion 3c in which the operator's finger holds the finger. Is provided. Further, the lens installation portion 3b is provided with a lid 6 that can be freely opened and closed, and the lens installation portion 3b is provided with a fixing projection 3d for restricting the movement of the lens 2. The main body 3 is provided with an intermediate support portion 3e that pivotally supports the plunger 4, and a base end support member 7 that pivotally supports the plunger 4 is also provided on the base end side of the main body 3. In FIG. 1, the main body 3 and the base end support member 7 are configured as separate members, but both members have good lubrication characteristics and low frictional resistance. It is also possible to configure. The main unit 3 It is possible to manufacture the nozzle 3a and the gripping part 3c separately, and then assemble them together by assembling.

[0023] Here, since the intraocular lens insertion device 1 to which the present invention is applied is a medical device, the material of the constituent members of the device is required to be a physically stable material. The In particular, the materials used at the site of insertion into the eye must be biologically safe. For example, as a result of FDA (Food and Drug Administration) certified as an implant material, ISO (International Standardization Organization) standardized as an implant material, or a test conducted in accordance with ISO 10993, there are no problems! It is required that the material is confirmed. As a material that satisfies these requirements, for example, polyethylene, polypropylene, or the like can be used as the material of the cylindrical main body 3.

[0024] The lens 2 also has a force with an optical part 2a which is a lens body and two support members 2b for fixing the position of the optical part 2a in the eyeball. The support member 2b has a thin beard shape. This lens 2 is made of a flexible material such as soft acrylic and can fold the lens itself.

The plunger 4 includes a portion 4a having an outer diameter that is slightly smaller than the inner diameter of the proximal support member 7, and a portion 4b having an outer diameter that is slightly smaller than the inner diameter of the nozzle. A portion 4 a having an outer diameter slightly smaller than the inner diameter of the base end support member 7 is slidably inserted into the base end support member 7. A portion 4b having an outer diameter slightly smaller than the inner diameter of the nozzle 3a is slidably inserted into the intermediate support portion 3e of the main body.

A panel 5 as an elastic body is attached between the main body 3 and the plunger 4. Specifically, a string spring 5 is mounted between the right end surface of the intermediate support portion 3e of the main body and the step portion 4c of the plunger. This string spring 5 must have an appropriate panel constant and an appropriate deformation amount! /, Which will be described later.

When the lens 2 is inserted into the eyeball using such an intraocular lens insertion device 1, the operator can insert the lens 2 into the eyeball with a single hand operation. Specifically, the grasping portion 3c of the main body is grasped by the index finger and middle finger of one hand, and the abdomen of the thumb is brought into contact with the base end 4d of the plunger and the plunger 4 is pushed into the main body 3. Then lens 2 is plunge It is pressed by the tip of the nozzle 4 and is pushed into the nozzle 3a while being folded at the tapered lens transition portion 3f. When the plunger 4 is further pushed in, the lens 2 moves in the nozzle 3a and is released into the eyeball from the opening 3g at the tip of the nozzle.

[0028] The lens moving stroke from the lens installation portion 3b to the opening 3g of the nozzle tip, that is, the pressing force (F) of the plunger 4 in the moving stroke (X) of the plunger 4 has a characteristic tendency that is not constant. The inventor has found to show. Figure 2 shows this situation, with the horizontal axis representing the plunger travel (X) and the vertical axis representing the plunger pressing force (F). Here, the horizontal axis represents the travel of the plunger of the injector shown in Fig. 1 (X). That is, in order to release the lens 2 from the nozzle opening 3g in FIG. 1, it is necessary to move the plunger 4 to the left side of the right side force. The horizontal axis in FIG. 2 is the movement stroke (X) itself of this plunger. The horizontal axis travels from the right side to the left side. As a result, unlike a general chart, the point where the horizontal axis intersects the vertical axis indicates the position after the lens 2 that is not at the origin is released.

FIG. 2 is a characteristic diagram in which the relationship between the movement stroke (X) and the pressing force (F) of the plunger 4 of the intraocular lens insertion device 1 without the elastic body 5 is measured. This characteristic has been measured for many actual objects, and it has been found that although there are some individual differences, it shows an almost constant relationship. Even if the same intraocular lens insertion device is used, the characteristics will be different because the lens thickness will be different if the power of the intraocular lens is different. As a matter of course, the peak value of the pressing force becomes large in the case of a thick lens having a high frequency. Here, the point (i) on the horizontal axis corresponds to the point (i) in FIG. 1, that is, the tip position of the nozzle 3a. The (mouth) point on the horizontal axis corresponds to the (mouth) point in FIG. 1, that is, the boundary position between the lens transition portion 3f and the nozzle 3a.

[0030] It should be noted that the speed at which the plunger 4 is pushed may be a speed suitable for inserting the lens 2 into the eye, and generally a force of about 70 mm / min to about 20 mm / min to 200 mm / min. 130 mm / min is preferred.

[0031] First, when the lens 2 is moved by pushing the right side force, the pressing force (F) until the outer periphery of the lens 2 comes into contact with the tapered inner wall of the lens transition portion 3f is between the main body 3 and the plunger 4 and between the main body 3 and Only the sliding resistance between lenses 2 is small. Next, move lens 2 to the outer periphery of lens 2. When the lens touches the tapered inner wall of the S lens transition part 3f, the lens 2 is deformed and begins to fold. Then, in addition to the sliding resistance, the force required for the deformation of the lens 2 needs to be applied to the plunger 4 as well, so the pressing force (F) of the plunger 4 starts to increase rapidly. Then, when the lens 2 is moved to the left side and reaches the position (mouth) point where the lens 2 contacts the nozzle 3a from the tapered inner wall of the lens transition portion 3f, the force required to fold the lens becomes maximum. The plunger pressing force (F) reaches its peak. Thereafter, when the plunger 4 is further pressed and the lens 2 is moved to the left side, the pressing force (F) required for the plunger is rapidly reduced. The reason why the pressing force (F) required to move the lens 2 in the substantially cylindrical nozzle 3a suddenly decreases is that the force required to fold the lens 2 becomes unnecessary and the nozzle opening 3g is folded. This is based on enlargement by receiving the internal pressure from the lens. Thus, when the elastic body is not provided in the injector, a peak in which the plunger pressing force (F) becomes extremely high during the movement stroke of the plunger is shown. As a result, at the stage (ii) when the folded lens 2 is released from the nozzle tip 3g, the pressing force (F) of the plunger suddenly decreases, and the tip of the plunger also occupies the eyeball. There was a risk of jumping inside.

FIG. 3 is a characteristic diagram showing the relationship between the travel stroke (X) of the brassiere 4 and the pressing force (F) when the lens 2 is not loaded into the intraocular lens insertion device 1 provided with the elastic body 5. is there. The significance of the vertical and horizontal axes is the same as in Fig. 2 (hereinafter also the same in Figs. 3 to 7 and 9). O The point (c) on the horizontal axis moves the plunger 4 The position where the panel 5 starts to be compressed by the step 4c is shown. Since the string spring 5 having linear characteristics is used as an elastic body, the plunger pressing force (F) increases linearly after the panel starts to deform.

FIG. 4 is a characteristic diagram showing the relationship between the movement stroke (X) of the plunger 4 and the pressing force (F) when the lens 2 is loaded into the intraocular lens insertion device 1 of the first embodiment and pushed out. It is. This is the case where the panel constant and the panel deformation amount are set appropriately. As a result, the characteristics shown in Fig. 2 and Fig. 3 are superimposed. In other words, when the plunger 4 is moved from the right side to the left side, the plunger pressing force (F) starts to rise when the plunger travel (X) reaches the panel deformation start position (c). If the plunger 4 is continuously moved to the left from there, the pressing force (F) of the plunger is such that the lens 2 contacts the nozzle inner wall force nozzle of the lens transition part 3f. It increases continuously until it reaches the field position (mouth) point. When the lens 2 is moved to the nozzle part 3a beyond the powerful boundary position, the plunger pressing force (F) increases again without significantly decreasing although it slightly decreases from the peak value at the (mouth) point. Begin to. Even after lens 2 is finally released from the nozzle opening 3g, the plunger pressing force (F) does not decrease. Therefore, even if the nozzle 3a force is also at the position (ii) where the lens 2 is released, the plunger pressing force (F) suddenly disappears, and there is no danger of the tip of the plunger surging and jumping into the eyeball. .

FIG. 5 is a characteristic diagram showing the relationship between the plunger travel (X) and the pressing force (F) when an elastic body having an elastic value different from that of the injector of the first embodiment is used. is there. This elastic body has an excessive panel reaction force against the force required to deform the lens, and has the advantage that the pressing force (F) of the plunger increases almost linearly. On the other hand, there is a drawback that the plunger pressing force (F) at the point (i) where the lens is released from the tip of the nozzle becomes too large.

[0035] FIG. 6 is a characteristic diagram showing the relationship between the plunger travel (X) and the pressing force (F) when an elastic body having an elastic value different from that of the elastic body shown in FIG. 5 is used. . This elastic body has a panel reaction force that is approximately appropriate for the force required to deform the lens. Although the plunger pressing force (F) is discontinuous, the plunger travel (X The plunger's pressing force (F) against) does not decrease.

FIG. 7 further shows the relationship between the plunger travel (X) and the pressing force (F) when an elastic body having an elastic value different from that shown in FIGS. 5 and 6 is used. FIG. This elastic body has an excessive panel reaction force against the force required to deform the lens, and the tip force of the nozzle The plunger's pressing force (F) at the point (i) where the lens is released is large. There is an advantage that it does not become too much. On the other hand, there is a drawback that the rate of decrease in the plunger pressing force (F) after the (mouth) point has passed is too large with respect to the initial peak value.

[0037] As described above, according to the intraocular lens insertion device 1 according to the present invention, the plunger pressing force (F) with respect to the movement stroke (X) of the plunger 4 is greatly increased even after the first peak has elapsed. Since it does not decrease, the plunger can be moved gently even with one-handed operation. Also, the plunger pressure against the plunger travel (X) Since the value of (F) does not decrease, the plunger can be moved gently even with one-handed operation. Therefore, the lens can be safely and reliably inserted into the eyeball. In the first embodiment, the plunger travel (X) after the plunger pressing force (F) reaches the first peak value should hold 60% or more of the peak value. This is defined based on the value that can be operated without the operator feeling uncomfortable when actually operating with one hand. Although this value varies slightly between individuals, considering safety, 75% or more is preferable, and 90% or more is even more preferable.

FIG. 8 is a cross-sectional view of an intraocular lens insertion device showing a second embodiment of the present invention. This intraocular lens insertion device 1 is characterized by comprising a plurality of elastic bodies 5a and 5b having different elasticity values. Since the basic configuration is the same as that of the first embodiment shown in FIG. 1, the description of the common portions is omitted, and only the portion having a configuration different from that of the first embodiment will be described. In the first embodiment, one elastic body 5 is disposed between the main body 3 and the plunger 4, but in this embodiment, two panel 5a and 5b having different panel constants and deformation amounts are disposed. Yes. In this embodiment, the deformation amount of the string hook spring 5a disposed on the inner side is set large, and the deformation amount of the string hook spring 5b disposed on the outer side is set small. A sliding ring 8 is slidably mounted on the plunger 4b between the right end of the string paddle panel 5a disposed on the inside and the step 4c of the plunger.

[0039] The pressing force (F) with respect to the movement stroke (X) of the plunger when the lens 2 is released using the intraocular lens insertion device having such a configuration will be described. FIG. 9 is a characteristic diagram showing the relationship between the plunger movement stroke (X) and the pressing force (F) when the lens 2 is not loaded in the intraocular lens insertion device of the second embodiment. is there. When the plunger 4 is moved from the right side to the left side, the pressing force (F) is small because only the sliding resistance between the plunger 4 and the main body 3 on which the plunger is supported is initially. The movement of the plunger 4 advances, and the string spring 5a disposed inside by the plunger step 4c starts to be compressed through the sliding ring 8. When reaching the point (c), it is disposed inside. The reaction force of string spring 5a is applied as the plunger pressing force. When the plunger is further moved to the left side, the string spring 5b disposed on the outside starts to be compressed by the plunger step 4c via the sliding ring 8. Then, after the position (mouth) point where the string spring 5b arranged outside starts to be compressed, two The reaction force of the string spring 5a, 5b is added to the plunger pressing force. Here, when the position (mouth) point at which the chord spring 5b disposed on the outside starts to be compressed coincides with the position where the force required to deform the lens is maximum, that is, the (mouth) point shown in FIG. It is possible to reduce the decrease in pressing force during the travel stroke after the plunger pressing force reaches its peak, and increase the pressing force after releasing the lens! ] Also has the advantage that it can be suppressed. Therefore, the panel reaction force with respect to the movement stroke (X) of the plunger can be made discontinuous by combining the panels 5a and 5b having a plurality of panel constants. As a result, an intraocular lens insertion device capable of suppressing the maximum value of the plunger's pressing force (F) can be realized.

FIG. 10 is a cross-sectional view of an intraocular lens insertion device showing a third embodiment of the present invention. This intraocular lens insertion device 1 is characterized in that the elastic value of the elastic body has a nonlinear characteristic. Descriptions of portions common to the first and second embodiments shown in FIG. 1 are omitted, and only portions having configurations different from those of the embodiments are described. In the first embodiment and the second embodiment, the elastic body 5 is disposed in the cylindrical main body 3, but in this embodiment, the elastic bodies 5c to 51¾ are provided between the main body 3 and the base end 4d of the plunger. It is arranged. In FIG. 10 (a), two string springs 5c and 5d having different elastic values are arranged between the main body 3 and the base end 4d of the plunger. FIG. 10 (b) shows a string spring 5e in which the wire diameter gradually changes from one end to the other end between the main body 3 and the base end 4d of the plunger. Further, FIG. 10 (c) shows a string hook spring 5 in which the string hook diameter gradually changes from one end to the other end between the main body 3 and the base end 4d of the plunger. A sliding ring 8 is attached to one end or both ends of each of the string springs 5c to 5f in order to ensure good seating when the panel is compressed. According to these embodiments, since the elastic value of the elastic body exhibits a non-linear characteristic with respect to the movement stroke of the plunger, the pressing force of the plunger before and after the nozzle is released is reduced. It can be designed more precisely.

FIG. 11 is a cross-sectional view of an intraocular lens insertion device showing a fourth embodiment of the present invention. This intraocular lens insertion device 1 has an elastic body 5 disposed between a main body 3 and a plunger 4, and a sliding resistance increasing mechanism 9 is provided on an outer surface 4a of the plunger that slides with the inner surface of the cylindrical main body 3. It is prepared. The basic configuration of this embodiment is the same as that of the first embodiment shown in FIG. The description of the minute is omitted, and only a portion having a configuration different from the first embodiment will be described. In this embodiment, a sliding resistance increasing mechanism 9 is provided on the outer surface 4a of the plunger that slides with the inner surface of the cylindrical main body 3. Specifically, one or more protrusions 9a to 9c are provided on the outer surface 4a of the plunger. The axial position of the plunger 4 where the protrusions 9a to 9c are provided corresponds to the position where the pressing force of the plunger 4 starts to decrease when the deformation resistance required for folding the lens 2 is lost and the protrusions 9a to 9c are not provided. ing. With such a configuration, a sudden change in the plunger pressing force with respect to the plunger travel can be mitigated.

[0042] In FIG. 11, a string spring 5 as an elastic body is disposed between the main body 3 and the plunger 4, and a protrusion 9a to 9c as a sliding resistance increasing mechanism is provided on the outer surface 4a of the plunger. Although an example has been shown in which a rapid change in the pressing force of the plunger with respect to the movement stroke of the plunger is mitigated by a combination of the compression resistance of the string spring 5 and the sliding resistance of the protrusions 9a to 9c. Only one of the compression resistance force of the screw 5 and the sliding resistance force of the protrusions 9a to 9c may be used.

[0043] While the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above embodiment, the intraocular lens 2 is set in a cartridge different from the force body 3 described in the case where the intraocular lens 2 is directly set in the cylindrical main body 3, and the cartridge is mounted. Needless to say, the present invention can also be applied to a cartridge-type intraocular lens insertion device used by being mounted on the main body 3.

[0044] Also, in the above-described embodiment, the description has been given for the case where the string spring is used as the elastic body 5. However, the elastic body 5 is not limited to the string panel, but is a foamed foam. It may be an elastic body that uses the elasticity of the material itself!

Claims

The scope of the claims

[1] A cylindrical main body that passes through a deformable intraocular lens and guides it into the eyeball,

A plunger housed in a reciprocating manner in the main body, pressing a intraocular lens and releasing it into the eyeball;

An intraocular lens insertion device comprising an elastic body and a Z or sliding resistance increasing mechanism between the main body and the plunger,

Pushing force (F) force of the plunger Inserting an intraocular lens characterized in that it can hold 60% or more of the peak value in the movement stroke (X) of the plunger after reaching the first peak value Instruments.

[2] a cylindrical body that passes through a deformable intraocular lens and guides it into the eyeball;

The intraocular lens insertion device, wherein the value of the plunger pressing force (F) with respect to the plunger moving stroke (X) does not decrease.

[3] The intraocular lens insertion device according to [1] or [2], wherein the elastic body has a plurality of elastic body forces having different elasticity values.

4. The intraocular lens insertion device according to claim 1, wherein an elastic value of the elastic body has a nonlinear characteristic.