Intravitreal administration tool and needleless syringe

Abstract

This intravitreal administration tool (50) for positioning a needleless syringe for injecting an injection target substance into the vitreous body of an eyeball without employing an injection needle comprises: a guide (54) at least a part of which is formed in a shape corresponding to the outer edge of the cornea in the eyeball; and a positioning part (51) which is connected to the guide (54) and the needleless syringe, and which, when the guide (54) is disposed so as to match the outer edge of the cornea, positions an ejection port (77) for ejecting the injection target substance in the needleless syringe at a position away from the outer edge of the cornea by a prescribed distance from the outer edge of the cornea to the rear of the eyeball.

Description

Intravitreal injection devices and needleless syringes

[0001] The present invention relates to an intravitreal injection device and a needleless syringe.

[0002] Intravitreal injections are used to treat conditions such as age-related macular degeneration, retinal vein occlusion, and diabetic macular edema. When injecting intravitreal injections, if the injection site is too close to the cornea, there is a risk of damaging the cornea or lens, and if the injection site is too far from the cornea and too far to the back of the eyeball, there is a risk of damaging the retina; therefore, guidelines state that "the injection needle should be inserted 3.5 to 4.0 mm posterior to the corneal limbus."

[0003] Patent Document 1 discloses an intravitreal injection fixation device that includes an injection needle fixing plate having an injection needle insertion hole and an eyeball fixator that includes a ring having an uneven eyeball contact surface and that fixes the position of the injection needle insertion hole on the eyeball.

[0004] WO 2007 / 052730

[0005] The intravitreal injection fixation device of Patent Document 1 is configured to identify the injection location by inserting a needle into a needle insertion hole, and therefore cannot be applied to needleless syringes. Furthermore, with the intravitreal injection fixation device of Patent Document 1, the practitioner must hold the intravitreal injection fixation device with one hand, align the ring with the limbus, hold the syringe with the other hand, insert the injection needle into the eyeball through the needle insertion hole, and press the plunger to inject the medicinal solution. This means that the practitioner must perform separate operations with both hands, and must pay attention to the operation of each hand, which makes it difficult to perform the intravitreal injection correctly, even when using the intravitreal injection fixation device.

[0006] The technology of the present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a technology that makes intravitreal injection easier.

[0007] In order to solve the above problems, the intravitreal injection device of the present disclosure is an intravitreal injection device for positioning a needleless syringe that injects an injection target substance into the vitreous of an eyeball without using an injection needle, and includes: a guide, at least a portion of which is formed in a shape corresponding to the outer edge of the cornea of ​​the eyeball; and a positioning unit that is connected to the guide and the needleless syringe and, when the guide is positioned in accordance with the outer edge of the cornea, positions an injection port of the needleless syringe that injects the injection target substance at a position a predetermined distance behind the eyeball from the outer edge of the cornea.

[0008] In the intravitreal injection device, the needle-free syringe may include a storage section having a storage space for storing the injection target substance and having the injection outlet through which the injection target substance is injected into the target area, and the positioning section may be attached to the storage section of the needle-free syringe.

[0009] In the intravitreal injection device, the needle-free syringe may include a storage section having a storage space for storing the injection target substance and having the injection outlet through which the injection target substance is injected into the target area, and a holding section for holding the storage section, and the positioning section may be attached to the holding section of the needle-free syringe.

[0010] In the intravitreal injection device, the guide may be formed in a curved shape that follows the outer edge of the cornea, and the positioning unit may position the injection port of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the guide is placed along the outer edge of the cornea.

[0011] In the intravitreal injection device, the guide may be formed in a straight line tangent to a part of the outer edge of the cornea, and the positioning unit may position the injection outlet of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the straight line portion of the guide is arranged along a tangent to the outer edge of the cornea.

[0012] In the intravitreal injection device, the positioning portion may include an uneven portion that suppresses positional deviation on a surface that faces the eyeball when the guide is placed along the outer edge of the cornea.

[0013] In the intravitreal injection device, the guide may have an uneven portion on a surface facing the eyeball when the guide is placed along the outer edge of the cornea, the uneven portion preventing positional displacement.

[0014] In order to solve the above problems, the needle-free syringe of the present disclosure is a needle-free syringe that injects an injection target substance into the vitreous body of an eyeball without using an injection needle, and comprises: a storage unit that has a storage space for storing the injection target substance and has an ejection outlet through which the injection target substance is ejected into the eyeball; a drive unit that applies ejection energy for ejecting the injection target substance; and an intravitreal injection device that determines the injection position of the needle-free syringe relative to the eyeball, wherein the intravitreal injection device comprises: a guide that has at least a portion formed in a shape corresponding to the outer edge of the cornea of ​​the eyeball; and a positioning unit that is connected to the guide and the needle-free syringe and that positions the ejection outlet at a position a predetermined distance behind the eyeball from the outer edge of the cornea when the guide is positioned in accordance with the outer edge of the cornea.

[0015] In the needle-free syringe, the positioning portion of the intravitreal injection device may be attached to the housing portion.

[0016] The needle-free syringe may further include a holding part that holds the container part, and the positioning part of the intravitreal injection device may be attached to the holding part.

[0017] In the needle-free syringe, the guide may be formed in a curved shape that follows the outer edge of the cornea, and the positioning unit may position the injection port of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the guide is placed along the outer edge of the cornea.

[0018] In the needle-free syringe, the guide may be formed in a straight line tangent to a part of the outer edge of the cornea, and the positioning unit may position the injection port of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the straight line portion of the guide is arranged along a tangent to the outer edge of the cornea.

[0019] In the needle-free syringe, the positioning portion may include an uneven portion that suppresses positional deviation on a surface that faces the eyeball when the guide is placed along the outer edge of the cornea.

[0020] In the needle-free syringe, the guide may include an uneven portion that suppresses positional deviation on a surface that faces the eyeball when the guide is placed along the outer edge of the cornea.

[0021] According to the present disclosure, a technique for facilitating intravitreal injection can be provided.

[0022] FIG. 1 is a diagram schematically showing the appearance of a syringe. FIG. 2 is a first cross-sectional view of the syringe, which cross section corresponds to the AA cross section in FIG. 4 described below. FIG. 3 is a second cross-sectional view of the syringe, which cross section corresponds to the BB cross section in FIG. 4 described below, which is perpendicular to the AA cross section. FIG. 4 is a diagram showing the configuration of a housing constituting the syringe 1. FIG. 5 is a diagram showing the schematic configuration of a syringe assembly. FIG. 6 is a cross-sectional view showing the schematic configuration of a container. FIG. 7 is an external view showing the schematic configuration of a container. FIG. 8 is a diagram showing the schematic configuration of an intravitreal administration device, and is a view (side view) of the intravitreal administration device from a direction perpendicular to the injection direction of the syringe. FIG. 9 is a cross-sectional view of FIG. 8. FIG. 10 is a view of the intravitreal administration device as seen from the distal end side. FIG. 11 is a view of the intravitreal administration device as seen from the proximal end side. FIG. 12 is a perspective view showing the schematic configuration of the intravitreal administration device. FIG. 13A is a diagram showing a state in which a guide is positioned so that the distance between the guide portion and the outer edge of the cornea is uniform. FIG. 13B is a diagram showing a state in which a guide is positioned so that the portion of the guide portion closest to the positioning portion coincides with the outer edge of the cornea. FIG. 14 is a schematic explanatory diagram showing the injection position when the guide is positioned to match the outer edge of the cornea. FIG. 15 is a diagram showing the schematic configuration of an intravitreal administration device and a container according to a second embodiment. FIG. 16 is a diagram showing the schematic configuration of an intravitreal administration device and a container according to a third embodiment. FIG. 17 is a diagram for explaining the positional relationship between a container and a container holder according to the third embodiment. FIG. 18 is a cross-sectional view showing the schematic configuration of an intravitreal administration device and a container according to a fourth embodiment. FIG. 19 is a diagram showing the intravitreal administration device according to the fourth embodiment as viewed from the tip side. FIG. 20 is a diagram showing the schematic configuration of an intravitreal administration device according to a fifth embodiment. FIG. 21 is a schematic explanatory diagram showing the injection position when the intravitreal administration device is positioned to match the outer edge of the cornea. FIG. 22 is a diagram showing a modified example in which the circumferential length of the guide is formed even shorter than the example shown in FIG. 20. Figure 23 shows an example of a guide with linear guide portions, Figure 24 shows an example of the guide portions of Figure 23 aligned with the corneal limbus, and Figure 25 shows an example of a circular guide portion aligned with the corneal limbus.Fig. 26 is a diagram showing an example of a guide 54F in which a measurement starting point is set at a point other than the contact point between the guide portion and the outer edge of the cornea. Fig. 27 is a diagram showing an example of a guide portion having a curved convex shape toward the cornea. Fig. 28 is a diagram showing an example of a circular guide portion arranged to surround the injection position. Fig. 29 is a diagram showing an example of a guide portion that combines straight lines and curves.

[0023] First Embodiment A needle-free syringe (hereinafter simply referred to as "syringe") 1 according to an embodiment of the present disclosure will be described below with reference to the drawings. The syringe 1 is a needle-free syringe that uses the combustion energy of gunpowder to inject a projectile corresponding to the injection target substance of the present application into the eyeball (target area), i.e., a device that performs an injection by injecting the projectile into the target area without using a syringe needle.

[0024] Note that the configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of configurations are possible as appropriate within the scope of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the claims. In this embodiment, the terms "distal side" and "base side" are used to describe the relative positional relationship in the longitudinal direction of the syringe 1. The "distal side" refers to a position closer to the tip of the syringe 1, i.e., closer to the ejection port 77, as described below, and the "base side" refers to the direction opposite to the "distal side" in the longitudinal direction of the syringe 1, i.e., the direction toward the igniter 22 in the syringe assembly 10 (see FIG. 5, described below).

[0025] <Configuration of syringe 1> Here, FIG. 1 is a diagram schematically illustrating the appearance of syringe 1. FIG. 2 is a first cross-sectional view of syringe 1, which cross section is cross section AA in FIG. 4 described below. FIG. 3 is a second cross-sectional view of syringe 1, which cross section is cross section BB in FIG. 4 described below, which cross section BB is perpendicular to cross section AA. FIG. 4 is a diagram showing the configuration of a housing 2 constituting syringe 1, and FIG. 5 is a diagram showing the schematic configuration of a syringe assembly 10. Syringe 1 is formed by attaching syringe assembly 10 to housing 2. Furthermore, a power cable 3 ( FIG. 1 ) for supplying a drive current to igniter 22 in syringe assembly 10 is connected to housing 2.

[0026] In the following description of the present application, the ejected liquid to be ejected into the target area by the syringe 1 is formed by containing a predetermined substance that exerts the efficacy or function expected in the target area in a liquid medium. In the ejected liquid, the predetermined substance may be dissolved in the liquid medium, or may simply be mixed without being dissolved.

[0027] Examples of the predetermined substance contained in the injection fluid include, for example, a biologically-derived substance that can be injected into a target area of ​​a living body, or a substance that exhibits a desired physiological activity. Examples of biologically-derived substances include DNA, RNA, nucleic acids, antibodies, and cells. Examples of physiologically-active substances include low-molecular-weight, protein- and peptide-based medicines, vaccines, inorganic substances such as metal particles for thermotherapy and radiotherapy, and various substances with pharmacological or therapeutic effects, including carriers. Furthermore, the liquid medium for the injection fluid may be any substance suitable for administering these predetermined substances into the target area, regardless of whether it is aqueous or oil-based. Furthermore, the viscosity of the liquid medium is not particularly limited, as long as the predetermined substance can be injected using the syringe 1.

[0028] In the syringe 1, the syringe assembly 10 is configured to be detachable from the housing 2. An accommodation space 75 (see FIG. 5 ) formed between a container (accommodating portion) 70 and a plunger 80 included in the syringe assembly 10 is filled with an injection liquid in a preparation stage before the syringe 1 is actuated, and the syringe assembly 10 is a unit that is replaced each time the injection liquid is to be injected. Details of the syringe assembly 10 will be described later.

[0029] Meanwhile, the housing 2 is formed with a grip portion 2a that the user of the syringe 1 grasps for use, and is provided with multiple switches for operating the syringe 1 to inject the injection liquid. The syringe 1 is configured so that the user can grasp and operate it with one hand. The housing 2 will now be described with reference to FIG. 4 . In FIG. 4 , (a) shows the appearance of the housing 2 as viewed from the front, (b) shows the appearance of the housing 2 as viewed from the side, (c) shows the appearance of the housing 2 as viewed from the rear, and (d) shows the appearance of the housing 2 as viewed from above. Here, the “front” refers to the portion located distal to the user when the user grasps the housing 2, which is located on the left side in FIG. 4(b), and the “rear” refers to the portion located proximal to the user, which is located on the right side in FIG. 4(b). Therefore, when a user grasps the housing 2 with one hand, the user's fingertips are placed on the front of the housing 2, which is the distal side, and the user's wrist is positioned close to the rear of the housing 2, which is the proximal side. Moreover, "upper" refers to the area on the base end side of the syringe 1.

[0030] Taking into consideration such user gripping, a grip portion 2a is provided near the front of the housing 2 to make it easier for the user's fingertips to grip. Multiple dimples are formed on the grip portion 2a to improve the grip for the user's fingertips. Furthermore, to further stabilize the user's grip of the housing, the outer periphery on the front side of the grip portion 2a is gently uneven (see FIG. 4(b)), making it easier for the user's index finger and middle finger to grip.

[0031] Furthermore, the housing 2 is provided with two operation switches, a first switch 5 and a second switch 6, for operating the syringe 1. The first switch 5 and the second switch 6 are connected to a control unit such as a microcomputer (not shown), which controls the supply of ignition current to the igniter 22 based on signals from each switch, thereby controlling the operation of the syringe 1. Here, the first switch 5 is a sliding switch provided at the rear of the housing 2, and its sliding direction is the vertical direction of the housing 2 (the direction connecting the tip and base ends). The first switch 5 is constantly biased upward, and the user can place the syringe 1 in a standby state by continuing to slide the first switch 5 downward (toward the tip) against this biasing force for a certain period of time. This standby state is a state in which the syringe 1 is ready to eject the injection liquid, and is a state in which injection is performed if the user performs additional operations.

[0032] Next, the second switch 6 is a push-down switch provided on the upper inclined surface 2b of the housing 2, and a user can push the second switch 6 inwardly of the housing 2. When the syringe 1 is placed in a standby state by operating the first switch 5, the control unit is configured to supply an ignition current to the igniter 22 by pushing the second switch 6. Furthermore, a connector 4 to which a power cable 3 is connected is provided in front of the upper inclined surface 2b of the housing 2. In this embodiment, the connector 4 is a USB connector, and the power cable 3 is detachable from the housing 2.

[0033] As described above, in this embodiment, power for operating igniter 22 is supplied from the outside via power cable 3. Alternatively, a battery for supplying power may be provided inside housing 2. In this case, as long as power remains in the battery, housing 2 can be used repeatedly by replacing syringe assembly 10. When the battery runs out of power, the battery can simply be replaced.

[0034] Here, a schematic configuration of the syringe assembly 10 is shown in Fig. 5. As shown in Figs. 2 and 3, the syringe assembly 10 is attached to the housing 2 to form the syringe 1, and specifically, the syringe assembly 10 is an assembly including an actuator (driving unit) 20, an attachment 30, an intravitreal injection device 50, a container 70, and a plunger 80. Assembly of the syringe assembly 10 will be described later.

[0035] The actuator 20 has a cylindrical body 21. The body 21 has a central portion 21a at its center, a distal end portion 21b at its distal end, and a proximal end portion 21c at its proximal end. The distal end portion 21b, the central portion 21a, and the proximal end portion 21c of the body 21 are connected to each other through their respective internal spaces. An opening 27 is provided at the distal end of the distal end portion 21b. The proximal end portion 21c of the body 21 is fitted with an igniter 22, which is an electric igniter that burns an ignition charge to generate ejection energy. The igniter 22 has an ignition pin 22b to which an ignition current is supplied from the outside. The ignition pin 22b is coupled to the socket 7 on the housing 2 when the syringe assembly 10 is fitted to the housing 2. The igniter 22 is fitted to the body 21 in such a manner that combustion products generated by activation of the igniter 22 are released toward the central portion 21a of the body 21. That is, the igniter 22 is attached to the base end 21c of the body 21 so that the discharge surface 22c of the combustion products faces the central portion 21a.

[0036] Here, the combustion energy of the ignition charge used in the igniter 22 serves as the energy required for the syringe 1 to inject the propellant into the target area. The ignition charge may preferably be zirconium and potassium perchlorate (ZPP), titanium hydride and potassium perchlorate (THPP), titanium and potassium perchlorate (TiPP), aluminum and potassium perchlorate (APP), aluminum and bismuth oxide (ABO), aluminum and molybdenum oxide (AMO), aluminum and copper oxide (ACO), aluminum and iron oxide (AFO), or a combination of these explosives. These explosives generate high-temperature, high-pressure plasma during combustion immediately after ignition, but exhibit a characteristic whereby the generated pressure drops rapidly when the temperature returns to room temperature and the combustion products condense because they contain no gaseous components. Other explosives may also be used as long as they are capable of injecting the appropriate propellant.

[0037] The body 21 is a cylindrical member, and the internal space of the central portion 21a serves as the combustion chamber 20a. Furthermore, a male thread portion 26 is formed on a portion of the outer surface of the central portion 21a. The male thread portion 26 is configured to threadably mate with a female thread portion 32 of the attachment 30, which will be described later, and the effective lengths of the male thread portion 26 and the female thread portion 32 are determined so as to ensure the necessary connecting force between them. The internal space of the tip portion 21b adjacent to the central portion 21a is formed cylindrical, and a piston 40 is slidably disposed therein.

[0038] When the igniter 22 is activated and combustion products are released into the combustion chamber 20a, the pressure therein rises, and the piston 40 receives the pressure and slides toward the tip end. In other words, the actuator 20 has a mechanism in which the igniter 22 is the actuation source and the piston 40 is the output part.

[0039] As shown in FIG. 5 , the attachment 30 is a component for mounting the actuator 20, plunger 80, and container 70. The body 31 of the attachment 30 can be made of a known resin such as nylon 6-12, polyarylate, polybutylene terephthalate, polyphenylene sulfide, or liquid crystal polymer. These resins may also contain fillers such as glass fiber or glass filler. Polybutylene terephthalate may contain 20 to 80% by mass of glass fiber, polyphenylene sulfide may contain 20 to 80% by mass of glass fiber, and liquid crystal polymer may contain 20 to 80% by mass of mineral. The material of the attachment 30 is not limited to resin, but may also be metal or ceramic.

[0040] 5, the actuator 20 is disposed in the interior space of the body 31 from the base end to the center. In the interior space where the actuator 20 is disposed, the base end 21c of the actuator 20 is located roughly in the base end region, and the center 21a and tip end 21b of the actuator 20 are located roughly in the tip end region, which has a smaller diameter than the base end. A female thread 32 is disposed on the inner wall surface of the body 31, and the female thread 32 is formed to threadably mate with the male thread 26 provided in the center 21a of the actuator 20.

[0041] 5, a plunger 80 is disposed in the interior space of the body 31 in a region closer to the tip end than the region in which the actuator 20 is disposed. The diameter of the region in which the plunger 80 is disposed is smaller than the diameter of the region in which the tip portion 21b of the actuator 20 is disposed, allowing the plunger 80 to slide.

[0042] Furthermore, a portion of the container 70 is generally disposed in a region on the tip side of the internal space of the body 31. The region in which the container 70 is disposed communicates with a region in which the plunger 80 is disposed on its base end side, and its tip side opens to the tip surface of the attachment 30. A female thread portion 36 for attaching the container 70 is formed on the inner wall of the region in which the container 70 is disposed. The female thread portion 36 is threadedly engaged with a male thread portion 74 of the container 70 shown in Figures 6 and 7 described below, thereby realizing the connection between the attachment 30 and the container 70.

[0043] Next, the plunger 80 will be described. The plunger 80 is a member that pressurizes the injection liquid using energy received from the piston 40, and has a plunger rod 81 and a stopper portion 82. The plunger rod 81 is formed, for example, from a resin material that is suitable for pressurization, but is not limited to this and may be formed, for example, from the same type of material as the attachment 30.

[0044] A stopper portion 82 made of an elastic material such as rubber is attached to the tip side of the plunger rod 81. Specific materials that can be used for the stopper portion 82 include, for example, butyl rubber and silicone rubber. Other examples include styrene-based elastomers, hydrogenated styrene-based elastomers, and mixtures thereof with polyolefins such as polyethylene, polypropylene, polybutene, and α-olefin copolymers; oils such as liquid parabens and process oil; and powdered inorganic materials such as talc, cast, and mica. Furthermore, the stopper portion 82 can be made of various rubber materials (especially vulcanized rubbers) such as polyvinyl chloride-based elastomers, olefin-based elastomers, polyester-based elastomers, polyamide-based elastomers, polyurethane-based elastomers, natural rubber, isoprene rubber, chloroprene rubber, nitrile-butadiene rubber, and styrene-butadiene rubber, as well as mixtures thereof. Furthermore, since the stopper portion 82 pressurizes the injection liquid while sliding within the container 70 described below, the surface of the stopper portion 82 and the inner wall surface 75a of the container 70 may be coated or surface-treated with various substances in order to ensure or adjust the slidability between the stopper portion 82 and the inner wall surface 75a of the storage space 75 of the container 70. Examples of such coating agents that can be used include PTFE (polytetrafluoroethylene), silicone oil, diamond-like carbon, and nanodiamond.

[0045] FIG. 6 is a cross-sectional view showing a schematic configuration of the container 70, and FIG. 7 is an external view showing a schematic configuration of the container 70. The container 70 is a member that stores the injection liquid and defines a flow path for injecting the injection liquid pressurized by the plunger 80 into a target area. The container 70 is formed from a material that takes into consideration the pressurization by the plunger and the determination of the flow path. The container 70 of this embodiment is formed from a resin material. Note that the container 70 is not limited to a resin material and can be formed from, for example, the same type of material as the attachment 30.

[0046] The container 70 has a storage space 75 that can contain the injection liquid and is formed so that the stopper portion 82 of the plunger 80 can be advanced, and has a flow path 76 that connects the storage space 75 to an ejection port 77 facing the outside of the container 70. Specifically, the container 70 has a cylindrical body portion 70a that defines the storage space 75, and a nozzle portion 70c that is connected to the tip side of the body portion 70a and defines the flow path 76. Furthermore, the nozzle portion 70c has a tip portion 70c2 that includes a part of the flow path 76 on the ejection port 77 side, and is configured to have a tapered portion 70c1 that connects the tip portion 70c2 to the body portion 70a and includes a tip-side outer surface 70c3 that is inclined with respect to the longitudinal central axis of the attachment 30. The intravitreal injection device 50, which will be described later, is fitted onto the outer periphery of the tip portion 70c2.

[0047] In the syringe assembly 10, as shown in FIG. 5 , the tip side of the plunger 80 is fitted into the accommodation space 75 of the container 70 so that the stopper portion 82 of the plunger 80 is slidable within the accommodation space 75 toward the nozzle portion 70c (toward the tip side). With the plunger 80 fitted into the container 70 in this manner, the space formed between the stopper portion 82 of the plunger 80 and the container 70 serves as a storage space for the injection liquid, i.e., a space in which the injection liquid is sealed. In other words, when the plunger 80 is fitted into the accommodation space 75 in the container 70 at its initial position, the tip surface of the stopper portion 82 and the inner wall surface of the container 70 located distal to the tip surface of the stopper portion 82 define the storage space. The flow path of the container 70 opens to the tip surface 73 of the nozzle portion 70c, and an injection port 77 is formed therein. Therefore, when the plunger 80 slides within the accommodation space 75 and the injection liquid contained in the accommodation space 75 is pressurized, the injection liquid passes through the flow path 76 and is injected from the injection port 77.

[0048] The inner diameter of a flow path 76 provided in the container 70 is smaller than the inner diameter of the storage space 75. With this configuration, the highly pressurized injection liquid is injected to the outside from the injection port 77. A male thread portion 74 for attaching the container 70 to the attachment 30 is formed on the outer periphery of the base end side of the container 70. The male thread portion 74 is threadedly engaged with the female thread portion 36 of the attachment 30.

[0049] The tip shape of the stopper portion 82 of the plunger 80 is formed to generally match the tip shape of the storage space 75 defined by the inner wall surface 75a near the portion where the storage space 75 and the flow path 76 connect (the innermost portion of the storage space 75). In the present embodiment, the tip shapes of the stopper portion 82 and the storage space 75 are both tapered, with the diameter decreasing toward the tip. This makes it possible to minimize the gap formed between the stopper portion 82 and the inner wall surface 75a of the container 70 when the plunger 80 slides during injection of the injection liquid and reaches the innermost portion of the storage space 75, thereby preventing the injection liquid from remaining in the storage space 75 and being wasted. However, the shape of the stopper portion 82 is not limited to a specific shape as long as the desired effect is obtained in the syringe 1 of this embodiment. Furthermore, the stopper portion 82 is formed with an outer diameter slightly larger than the storage space 75 of the container 70, so that when it is fitted into the storage space 75 in a radially compressed state, it makes suitable contact with the inner wall surface 75a so as to maintain airtightness between it and the container 70. Note that the outer diameter of the stopper portion 82 does not have to be larger than the storage space 75, and may be approximately the same as the diameter of the storage space 75 as long as appropriate injection of the injection liquid is possible.

[0050] <Assembly of Syringe 1> In assembling the syringe 1, first, assembly of the syringe assembly 10 will be described. With the stopper portion 82 of the plunger 80 inserted all the way into the storage space 75 of the container 70, the plunger 80 is pulled back, connecting the injection port 77 of the container 70 to the injection liquid. Because the stopper portion 82 and the inner wall surface 75a of the storage space 75 are in close contact with each other, this pulling back operation generates negative pressure within the storage space, allowing the injection liquid to be filled into the storage space 75 through the injection port 77. The amount of pulling back of the plunger 80 at this time is set to a degree that, when the container 70 is attached to the attachment 30 in this state, the plunger 80 (plunger rod 81) protruding from the container 70 reaches the region of the internal space of the attachment 30 where the piston 40 is located.

[0051] When the container 70, with the housing space 75 filled with injection liquid, is attached to the attachment 30, the actuator 20 is inserted into the attachment 30 from the base end side. The actuator 20 is inserted until the tip surface of the piston 40, located at the tip portion 21b, reaches the base end surface of the plunger 80 within the attachment 30. At this time, the male thread portion 26 provided on the central portion 21a of the actuator 20 threads into the female thread portion 32 of the attachment 30, thereby suitably coupling the actuator 20 and the attachment 30. At this time, the piston 40 incorporated in the actuator 20 is connected to the plunger 80. Note that the connection between the piston 40 and the plunger 80 is not limited to a simple abutment, and a fitting portion may be provided at the tip of the piston 40 and the base end of the plunger 80 to fit them together.

[0052] When the actuator 20 is attached to the attachment 30 to which the container 70 and plunger 80 are attached as described above, the plunger 80 is pushed from the piston 40 toward the tip, and the plunger 80 is positioned at a predetermined position (pre-actuation position) within the container 70. At this time, as the plunger 80 is pushed, excess ejected liquid within the container 70 is discharged from the ejection port 77, leaving a predetermined amount of ejected liquid within the container 70. Note that the volume of the space for accommodating the ejected liquid formed between the plunger 80 positioned at the pre-actuation position and the container 70 is determined to be a volume that ensures an appropriate amount of ejected liquid when the syringe 1 is actuated. Therefore, when the syringe assembly 10 is assembled as described above, the amount of ejected liquid accommodated within the accommodation space 75 of the container 70, i.e., the amount of ejected ejected liquid, is set to a predetermined amount.

[0053] The syringe assembly 10 configured in this manner is loaded into the housing 2 with the ignition pin 22b of the igniter 22 fitted into the socket 7 on the housing 2. This prepares the syringe 1 for use (see FIGS. 1 to 3). The user holds the housing 2 of the syringe 1 in one hand and continues to slide the first switch 5 located at the rear of the housing 2 for a predetermined period of time to place the syringe 1 in a standby state. The user then uses the intravitreal injection device 50, as described below, to position the syringe 1 relative to the eyeball and bring the injection port 77 into contact with the target area. In this state, the user presses the second switch 6, activating the igniter 22, pressurizing the injection liquid via the piston 40 and plunger 80, and injecting the injection liquid into the target area.

[0054] <Configuration of Intravitreal Administration Device> Next, a description will be given of the intravitreal administration device 50 provided at the tip of the syringe 1. Fig. 8 is a diagram showing a schematic configuration of the intravitreal administration device 50, and is a diagram (side view) of the intravitreal administration device 50 viewed from a direction perpendicular to the injection direction of the syringe 1. Fig. 9 is a cross-sectional view of Fig. 8, Fig. 10 is a diagram of the intravitreal administration device 50 viewed from the tip end side, Fig. 11 is a diagram of the intravitreal administration device 50 viewed from the base end side, and Fig. 12 is a perspective view showing a schematic configuration of the intravitreal administration device 50.

[0055] The intravitreal injection device 50 includes a guide 54, at least a portion of which is formed in a curved shape that follows the outer edge of the cornea of ​​the eyeball, a positioning unit 51 connected to the guide 54 and the syringe 1, and an uneven portion 52 provided on the eyeball side of the positioning unit 51. In this embodiment, the guide 54 is configured to follow the outer edge of the cornea, but because the outer edge of the cornea roughly coincides with the outer edge of the iris when the eyeball is viewed from the front, the outer edge of the cornea in the following description may be interpreted as the outer edge of the iris (black part of the eye). That is, the guide 54 may be configured so that at least a portion follows the outer edge of the iris.

[0056] The positioning portion 51 is an annular member, and the tip portion 70c2 of the nozzle portion 70c is passed through its inner space 511 and fitted onto the tip portion 70c2. That is, the intravitreal injection device 50 of this embodiment is attached to the container 70 of the syringe 1. The inner diameter of the positioning portion 51, i.e., the outer diameter of the inner space 511, is formed to be approximately the same as or slightly smaller than the outer diameter of the tip portion 70c2. Therefore, when the positioning portion 51 is fitted onto the tip portion 70c2, it is tightly fitted with no play between the positioning portion 51 and the tip portion 70c2. The positioning portion 51 may be detachably attached to the tip portion 70c2 or may be fixedly attached by adhesive bonding, welding, or the like. The positioning portion 51 of this embodiment has a circular shape surrounding the tip portion 70c2. The positioning portion 51 is configured so that the center axis of this circle, i.e., the position of a central axis 59 of the positioning portion 51 along the injection direction, coincides with the position of the injection port 77. In this embodiment, the injection port 77 is provided on the central axis of the tip portion 70c2, and the positioning portion 51 is attached coaxially to the tip portion 70c2. The shape of the positioning portion 51 is not limited to a circular shape, and may be a shape with a portion of a circle missing, such as a C-shape. Although the intravitreal injection device 50 of this embodiment is formed separately from the container 70, it may be formed integrally with the container 70. In this case, the shape of the positioning portion 51 is not limited to a ring shape, and may be any shape that connects the container 70 and the guide 54.

[0057] The base-end surface (base-end surface) 513 of the positioning portion 51 is tapered to fit along the tip-side outer surface (tapered surface) 70c3 of the tapered portion 70c1 of the nozzle portion 70c. As a result, when the positioning portion 51 is pressed against the target area during use of the syringe 1, the base-end surface 513 abuts against the tip-side outer surface 70c3 and is received, thereby accurately maintaining the positional relationship between the intravitreal injection device 50 and the syringe 1 in the injection direction. In addition, the tip-end surface of the positioning portion 51, i.e., the surface (base surface) 512 that faces the eyeball during use, is provided with an uneven portion (anti-slip) 52 that suppresses positional deviation relative to the eyeball.

[0058] The uneven portion 52 has a plurality of protruding portions 521, and each of the protruding portions 521 is erected on the base surface 512 of the positioning portion 51. The plurality of protruding portions 521 are provided at intervals from one another in the circumferential direction of the base surface 512. As a result, recessed portions 522 are formed between each of the protruding portions 521. In this embodiment, the intervals between the protruding portions 521 are uniform, and the protruding portions 521 are arranged rotationally symmetrically around the axis 59.

[0059] The guide 54 determines the position of the syringe 1 based on the cornea of ​​the eyeball, which is the target area, and is therefore positioned in contact with or close to the eyeball when the syringe 1 is in use. For example, the side of the guide 54 that contacts or comes close to the eyeball when in use is referred to as the distal end, and the side farther from the eyeball in the normal direction to the eyeball is referred to as the proximal end. The guide 54 has an annular peripheral wall 541, and an internal space 542 penetrating from the distal end to the proximal end is provided inside the peripheral wall 541. The distal end of the inner peripheral surface 543 of the peripheral wall 541, which defines the internal space 542, is formed as a guide portion 544 so as to follow the outer edge of the cornea of ​​the eyeball. The guide portion 544 of this embodiment is circular. That is, in the guide 54 of this embodiment, the peripheral wall 541 is formed in an annular shape so that the guide portion 544 is circular. Reference numeral 58 denotes the central axis of the circle formed by the peripheral wall 541. In the present embodiment, the inner edge on the tip side of peripheral wall 541 is guide portion 544, but the outer edge on the tip side of peripheral wall 541 may also be guide portion 544. That is, guide 54 may be configured so that the outer edge on the tip side of peripheral wall 541 (guide portion 544) follows the outer edge of the cornea when syringe 1 is in use. In this case, guide 54 is not limited to being annular, and may be disk-shaped or dome-shaped to cover the cornea.

[0060] The material of the guide 54 is not particularly limited, and may be, for example, resin, metal, ceramic, or the like. The guide 54 may also be formed of a transparent material. In this case, the guide 54 may be formed of a translucent or colored transparent material so that the guide portion 544 stands out. Furthermore, when at least a portion of the guide 54 is a transparent member, the guide portion 544 does not have to be the edge of the guide 54, but may be, for example, a line marked on the transparent member, which is configured to align with the outer edge of the cornea.

[0061] In Figures 8 and 9, reference numeral 90 denotes the region where the eyeball to be injected is located when the syringe 1 is in use. Reference numeral 92 denotes the position of the cornea of ​​the eyeball. The guide 54 and positioning unit 51 of the intravitreal injection device 50 are connected to each other so as to have a predetermined positional relationship. The axis 59 of the positioning unit 51 is located at a predetermined distance (interval) LA from the guide portion 544 of the guide 54. Here, the predetermined distance LA is, for example, 3.5 mm to 4.0 mm. Note that the predetermined distance LA is, for example, the distance (shortest distance) between the axis 59 and the point of the guide portion 544 closest to the axis 59. Alternatively, the predetermined distance LA may be the shortest distance between the guide portion 544 and the axis 59 when measured along a spherical surface corresponding to the eyeball.

[0062] The intravitreal injection device 50 is configured so that the central axis 59 of the positioning unit 51 forms a predetermined angle with respect to the guide 54. For example, when the guide 54 is positioned along the outer edge of the cornea, the positioning unit 51 is configured so that the central axis 59 faces the injection direction of the injection liquid. Specifically, in this case, the positioning unit 51 is configured so that the central axis 59 passes through the center of the eyeball or behind the center of the eyeball (toward the retina).

[0063] The surface of the tip of the guide 54, i.e., the surface (base surface) 545 that faces the eyeball when positioned along the outer edge of the cornea, is provided with an uneven portion (anti-slip) 53 that prevents misalignment with the eyeball. The uneven portion 53 of the guide 54 has a plurality of protrusions 531, similar to the uneven portion of the positioning portion 51 described above, and each of the protrusions 531 is erected on the base surface 545 of the guide 54. The plurality of protrusions 531 are spaced apart from one another in the circumferential direction of the base surface 545. As a result, recesses 532 are formed between each of the protrusions 531. In this embodiment, the protrusions 521 are spaced apart evenly, and the protrusions 531 are arranged rotationally symmetrically around the axis 58. The uneven portions 52 and 53 are not essential components and may be omitted as appropriate. For example, the uneven portion 52 may be provided only on the positioning portion 51 and the uneven portion 53 on the guide 54 may be omitted, or the uneven portion 53 may be provided only on the guide 54 and the uneven portion 52 on the positioning portion 51 may be omitted.

[0064] When the syringe 1 is in use, the guide 54 of the intravitreal injection device 50 is positioned so that the guide portion 544 is aligned with the outer edge of the cornea of ​​the target eyeball. FIG. 13A shows the guide 54 positioned so that the distance between the guide portion 544 and the outer edge 61 of the cornea is uniform. In the intravitreal injection device 50, the guide 54 and the positioning unit 51 are connected to each other so that a predetermined positional relationship is established. Therefore, when the guide portion 544 is aligned with the position of the cornea as shown in FIG. 13A , the position of the tip of the syringe to which the positioning unit 51 is attached is also determined. In this embodiment, when the guide 54 is aligned with the position of the cornea as shown in FIG. 13A , the injection port 77 of the syringe 1 is positioned 3.5 mm to 4.0 mm away from the outer edge of the cornea. Furthermore, when the tip surface of the guide portion 544 abuts against the eyeball along the entire circumference, the central axis 59 of the positioning unit 51 is at a predetermined angle with respect to the eyeball, and the injection direction of the injection liquid from the syringe 1 attached to the positioning unit 51 is also determined. 13A, the guide 54 is positioned so that the distance between the guide portion 544 and the outer edge 61 of the cornea is equal, but this is not limiting, and the guide 54 may be positioned so that a portion of the guide portion 544 coincides with the outer edge 61 of the cornea. FIG. 13B is a diagram showing a state in which the guide 54 is positioned so that the portion of the guide portion 544 closest to the positioning unit 51 coincides with the outer edge 61 of the cornea. The guide 54 and the positioning unit 51 may be configured so that the injection port 77 of the syringe 1 is positioned 3.5 mm to 4.0 mm away from the outer edge of the cornea by positioning the guide 54 as shown in FIG. 13B.

[0065] Figure 14 is a schematic explanatory diagram showing the injection position when the guide 54 is positioned in alignment with the outer edge of the cornea. Figure 14A shows the positional relationship between the guide portion 544 of the guide 54 and the injection position P1. The guide portion 544 is circular, and the starting point for measuring the distance LA from the guide portion 544 to the injection position P1 is shown as the measurement starting point 546.

[0066] 14B, when the guide portion 544 of the intravitreal injection device 50 is positioned along the outer edge of the cornea 92, the measurement starting point 546 is located on the outer edge of the cornea 92, and the injection position P1 is positioned in the normal direction of the outer edge of the cornea from the measurement starting point 546. In this case, the shortest distance between the outer edge of the cornea and the injection position P1 is the length of the interval LA.

[0067] In contrast, as shown in FIG. 14C , if the guide portion 544 of the intravitreal injection device 50 is positioned not along the outer edge of the cornea 92, even if the measurement starting point 546 is located on the outer edge of the cornea 92, the injection position P1 will not be positioned in the direction normal to the outer edge of the cornea from the measurement starting point 546. In this case, the shortest distance LB between the outer edge of the cornea and the injection position P1 will not be the length of the distance LA, and the distance from the injection position P1 to the outer edge of the cornea may be less than 3.5 mm. For this reason, the intravitreal injection device 50 of this embodiment is positioned so that the circular guide portion 544 is aligned with the outer edge of the cornea. Note that when the guide portion 544 of the guide 54 is positioned in alignment with the outer edge of the cornea, the guide portion 544 is not limited to contacting the outer edge of the cornea. For example, as shown in Figure 14D, when the guide 54 is positioned at a distance from the surface of the eyeball in the radial direction of the eyeball, the guide portion 544 may be positioned so that it overlaps with the outer edge of the cornea when viewed in the axial direction of the central axis 90X passing through the measurement starting point 546 and the center 99 of the eyeball.

[0068] Furthermore, when the intravitreal injection device 50 is pressed against an eyeball, the contact surfaces 523, 533 at the tip ends of the convex portions 521, 531 of the concave-convex portions 521, 531 contact the eyeball. Therefore, the contact surfaces 523, 533 of the convex portions 521, 531 are formed to conform to a predetermined curved surface corresponding to the eyeball. Here, the predetermined curved surface is, for example, a spherical surface. Forming the contact surfaces 523, 533 along a spherical surface with an average diameter of an eyeball allows the intravitreal injection device 50 to be used for general purposes. Alternatively, the contact surfaces 523, 533 may be formed along a spherical surface slightly larger than the average diameter of an eyeball, so that when the intravitreal injection device 50 is pressed against an eyeball, the inner sides of the contact surfaces 523, 533 mainly contact the eyeball with a diameter smaller than the average, and the outer sides of the contact surfaces 523, 533 mainly contact the eyeball with a diameter larger than the average. The predetermined curved surface along which the contact surfaces 523, 533 extend is not limited to a spherical surface, and may be a curved surface that deviates from a spherical surface as long as the contact surfaces 523, 533 of the respective convex portions 521, 531 contact the eyeball. For example, the contact surfaces 523, 533 may be formed along an aspherical surface having a higher curvature on the axis 58, 59 side (inner side) and a lower curvature on the side away from the axis 58, 59 (outer side) in the radial direction of the intravitreal injection device 50.

[0069] As described above, according to this embodiment, when the guide 54 is positioned along the outer edge of the cornea, the injection port 77 of the syringe 1, through which the injection target substance is injected, is positioned at a predetermined distance from the outer edge of the cornea toward the rear of the eyeball. As a result, the intravitreal injection device 50 of this embodiment can avoid damage to the cornea or lens caused by an injection position that is too close to the cornea, or damage to the retina caused by an injection position that is too far from the cornea, and can provide a technology that facilitates intravitreal injection.

[0070] Furthermore, when the guide 54 is positioned along the outer edge of the cornea, the intravitreal injection device 50 positions the injection outlet 77 of the syringe 1 at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea, thereby facilitating correct intravitreal injection in accordance with the guidelines.

[0071] Furthermore, when the intravitreal injection device 50 is pressed against the eyeball, the uneven portions 52, 53 come into contact with the surface of the eyeball, increasing the frictional force compared to when the tip of the syringe 1 is simply pressed against the eyeball, thereby preventing the syringe 1 from slipping relative to the target area of ​​the eyeball.

[0072] Second Embodiment This embodiment differs from the first embodiment in that the intravitreal injection device 50A is integrally formed with the container 70. Since the other configurations are the same as those of the first embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted.

[0073] 15 is a diagram showing the schematic configuration of an intravitreal injection device 50A and a container 70 according to the second embodiment. The intravitreal injection device 50A includes a guide 54 and a positioning portion 51A, and is integrally molded with the container 70. The positioning portion 51A is a columnar member that connects a side portion of the guide 54 to a side portion of the container 70. The positioning portion 51A connects the guide 54 to the container 70 so that the guide 54 and the container 70 have a predetermined positional relationship with each other. For example, the positioning portion 51A is provided at a position where the central axis 70X of the tip portion 70c2 of the container 70 is spaced a predetermined distance LA from the guide portion 544 of the guide 54.

[0074] Furthermore, the positioning unit 51A is configured so that the central axis 70X of the container 70 forms a predetermined angle with respect to the guide 54. For example, the positioning unit 51A connects the guide 54 and the container 70 so that, when the guide 54 is positioned along the outer edge of the cornea, the central axis 70X of the container 70 passes through the center of the eyeball or behind the center of the eyeball (toward the retina).

[0075] In this manner, when the guide 54 is positioned along the outer edge of the cornea, the intravitreal injection device 50A of this embodiment positions the injection port 77 at a position a predetermined distance away from the outer edge of the cornea and toward the rear of the eyeball. As a result, the syringe 1 equipped with the intravitreal injection device 50A of this embodiment can avoid damage to the cornea or lens caused by an injection position that is too close to the cornea, or damage to the retina caused by an injection position that is too far from the cornea, thereby providing a technology that facilitates intravitreal injection.

[0076] Third Embodiment This embodiment differs from the first embodiment in that it includes a container holder 71 that holds a container 70, and an intravitreal injection device 50B is attached to the container holder (holding portion) 71. Since the other configurations are the same as those of the first embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted.

[0077] Fig. 16 is a diagram showing a schematic configuration of an intravitreal injection device 50B according to the third embodiment and a container 700. Fig. 17 is a diagram for explaining the positional relationship between the container 700 and a container holder 71 according to the third embodiment.

[0078] The container 70B of this embodiment does not have a male thread portion that threadably engages with the female thread portion 36 formed on the inner wall of the tip end of the attachment 30. Therefore, the container 70B is attached to the attachment 30 by a container holder 71. The container holder 71 has a body portion 71a that defines a space that contains the container 70B, a threaded portion 71b that is connected to the base end of the body portion 71a and has a male thread that threadably engages with the female thread portion 36, and a contact portion 71c that is connected to the tip end of the body portion 71a and has an inner surface 71c1 (see FIG. 17 ) that comes into surface contact with the tip end outer surface 70c3 of the container 70B. As shown in FIG. 17 , the contact portion 71c has an opening 71c2 that allows the tip end 70c2 of the container 700 to pass through.

[0079] A positioning portion 51B of the intravitreal injection device 50B is attached to the distal end surface 71c3 of the container holder 71. The intravitreal injection device 50B includes the positioning portion 51B arranged around an axis 59 along the injection direction of the injection liquid so as to surround the periphery of the distal end portion 70c2, a guide 54 connected to the positioning portion 51B, and uneven portions 52, 53 provided on the distal ends of the positioning portion 51B and the guide 54. A proximal surface (proximal end surface) 514 of the positioning portion 51B is attached to the distal end surface 71c3 of the container holder 71 by adhesive bonding, welding, or the like. Note that although the intravitreal injection device 50 of this embodiment is formed separately from the container holder 71, it may be formed integrally with the container holder 71.

[0080] The container 700 is placed in the container holder 71 having the above configuration so that the distal end 70c2 passes through the opening 71c2. At this time, the container 700 has the injection objective substance filled in the placement space 75, and the plunger 80 is also loaded. In this placement state, the distal outer surface 70c3 of the container 700 and the inner surface 71c1 of the container holder 71 are in surface contact on the distal side, and the proximal end 70b of the container 700 and the threaded portion 71b of the container holder 71 are in contact on the proximal side. With the container 700 still placed in the container holder 71, the male thread formed on the threaded portion 71b of the container holder 71 and the female threaded portion 36 of the attachment 30 are threaded together until the proximal end face of the proximal end 70b of the container 700 comes into contact with the end face 35a of the third region 35 of the attachment 30. As a result, the container 700 is attached to the attachment 30 in a state in which the distal end outer surface 70c3 of the container 700 is pressed by the container holder 71 from the distal end toward the proximal end, i.e., in the opposite direction to the moving direction of the plunger 80, due to the fastening force of the screw engagement. At this time, the plunger 80 is disposed across the accommodation space 75 in the container 700 and the region in the attachment 30 in which the plunger 80 is generally disposed.

[0081] The process of assembling the syringe assembly 10, such as by attaching the actuator 20 to the attachment 30 in this state, and the process of assembling the syringe 1 are the same as those in the first embodiment described above.

[0082] As described above, the syringe 1 of this embodiment is provided with the intravitreal injection device 50B at the tip of the container holder 71, and when the guide 54 is positioned along the outer edge of the cornea, the injection port 77 for injecting the injection target substance in the syringe 1 is positioned at a predetermined distance from the outer edge of the cornea toward the rear of the eyeball. This makes it possible for the intravitreal injection device 50 of this embodiment to avoid damage to the cornea or lens caused by an injection position that is too close to the cornea, or damage to the retina caused by an injection position that is too far from the cornea, thereby providing a technology that facilitates intravitreal injection.

[0083] Fourth Embodiment This embodiment differs from the first embodiment in the configuration of the concave-convex portions 52C, 53C. Since the other configurations are the same as those of the first embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted. Fig. 18 is a cross-sectional view showing the schematic configuration of an intravitreal injection device 50C and a container 70 according to the fourth embodiment, and Fig. 19 is a view of the intravitreal injection device 50C as seen from the distal end.

[0084] As shown in Figures 18 and 19, the intravitreal injection device 50C of this embodiment comprises a positioning portion 51C surrounding the injection port 77, a guide 54 connected to the positioning portion 51C, and uneven portions 52C and 53C provided on the target area side of the positioning portion 51C and the guide 54.

[0085] The uneven portion 52C has a plurality of convex portions 521C arranged concentrically on a surface (base surface) 512 facing the target area of ​​the positioning portion 51C. The convex portions 521C are spaced apart from one another in the radial direction of the base surface 512. As a result, concave portions 522C are formed between the convex portions 521C. In this embodiment, the convex portions 521C are spaced apart evenly, and the convex portions 521C are arranged rotationally symmetrically around the axis 59. Although each convex portion 521C is formed in a circular shape when viewed from the tip side, it may be divided into a plurality of portions so that a portion of the circle is missing.

[0086] Furthermore, the uneven portion 53C has a plurality of convex portions 531C erected concentrically on a surface (base surface) 545 facing the target area of ​​the guide 54. The convex portions 531C are spaced apart from one another in the radial direction of the base surface 545. As a result, concave portions 532C are formed between the convex portions 531C. In this embodiment, the convex portions 531C are spaced apart evenly, and the convex portions 531C are arranged rotationally symmetrically around the axis 58. Although each convex portion 531C is formed in a circular shape when viewed from the tip side, it may be divided into a plurality of portions so that a portion of the circle is missing.

[0087] Thus, according to this embodiment, when the injection port 77 is pressed against the eyeball during use of the syringe 1, the uneven portions 52C, 53C of the intravitreal injection device 50C come into contact with the surface of the eyeball, increasing the frictional force compared to when the injection port 77 is simply pressed against the eyeball, thereby preventing the syringe 1 from slipping relative to the eyeball and providing a technology that makes intravitreal injection even easier.

[0088] Fifth Embodiment This embodiment differs from the first embodiment in the configuration of the guide 54D. Since the other configurations are the same as those of the first embodiment, the same elements are denoted by the same reference numerals, and a repeated description will be omitted.

[0089] Fig. 20 is a diagram showing a schematic configuration of an intravitreal injection device 50D according to the fifth embodiment. As shown in Fig. 20, in the intravitreal injection device 50D of this embodiment, a peripheral wall 541D of a guide 54D is formed in a semicircular shape when viewed from the proximal end side. That is, compared to the guide 54 of the first embodiment, the guide 54D of this embodiment has a shape in which the half on the side farther from the positioning portion 51 is cut out and the half on the side connected to the positioning portion 51 is left.

[0090] Figure 21 is a schematic explanatory diagram showing the injection position when the intravitreal injection device is positioned in alignment with the outer edge of the cornea. Figure 21A shows the positional relationship between the guide portion 544 of the intravitreal injection device 50D of this embodiment and the injection position P1. The guide portion 544 of this embodiment is semicircular and, as in the first embodiment, is positioned along the outer edge of the cornea. In this case, the intravitreal injection device 50D of this embodiment is connected to the guide 54D and the positioning unit 51 so that the injection position P1 is located in the normal direction from the measurement starting point 546 to the outer edge of the cornea. Therefore, when the guide portion 544 of the guide 54D is positioned along the outer edge of the cornea during use, the positioning unit 51 positions the injection outlet 77 of the syringe 1 at a predetermined distance posterior to the eyeball from the outer edge of the cornea. As a result, the syringe 1 equipped with the intravitreal injection device 50D can avoid the injection position being too close to the cornea, which could damage the cornea or lens, or the injection position being too far from the cornea, which could damage the retina, thereby providing a technology that makes intravitreal injection easier.

[0091] Furthermore, the guide 54D of this embodiment has a smaller contact area with the eyeball than the guide 54 of the first embodiment, which reduces the possibility of damage to the eyeball even if the eyeball suddenly moves while the guide 54D is pressed against the eyeball. Furthermore, the intravitreal injection device 50D is made smaller and easier to handle during the procedure, further facilitating intravitreal injection. Furthermore, the smaller size of the guide 54D reduces manufacturing costs, transportation costs, and management costs.

[0092] In this embodiment, the semicircular guide 54D is provided on the side closer to the positioning portion 51. However, this is not limiting, and the guide 54D may be formed in another portion of the circumference surrounding the cornea. Furthermore, the guide 54D is not limited to a semicircular shape, as long as at least a portion of it is configured to follow the outer edge of the cornea. Figure 22 is a diagram showing a modified example in which the circumferential length of the guide 54D is formed even shorter than in the example of Figure 20. By forming the guide 54D shorter in this way, it is possible to further reduce the possibility of damage to the eyeball, facilitate handling during treatment, and reduce costs, compared to the example of Figure 20.

[0093] <Modifications> In the above-described embodiment, examples of guides 54 and 54D having curved guide portions 544 were shown, but this is not limiting, and the guide of the intravitreal injection device may also have linear guide portions. Fig. 23 is a diagram showing an example of a guide 54E having linear guide portions. Fig. 23A shows an example in which four linear guide portions 544 are connected to form each side of a rectangle, forming a rectangular guide 54E. Fig. 23B shows an example in which one side of the rectangle in Fig. 23A is omitted. Fig. 23C shows an example in which the guide 54E is formed in a straight line.

[0094] Figure 24 is a diagram showing an example in which the guide portions of Figure 23 are positioned in alignment with the corneal periphery. As shown in Figure 24A, the guide portions 544 shown in Figure 23A are positioned to surround the cornea 92. In this case, for example, of the four guide portions 544, at least the guide portion 544A having the measurement starting point 546 is positioned in alignment with the corneal periphery. Specifically, the guide portion 544A contacts the corneal periphery at the position of the measurement starting point 546, and the guide portion 544A is positioned so as to be along the tangent to the corneal periphery at the position of the measurement starting point 546. In this way, by positioning the straight portion of the guide 54E (guide portion 544A) so as to be along the tangent to the corneal periphery, the injection position P1 is positioned in the direction normal to the corneal periphery from the measurement starting point 546, and a predetermined distance LA is secured between the corneal periphery and the injection position P1.

[0095] 23 , the linear guide portion 544A is arranged so as to follow a tangent to the corneal outer edge rather than along the corneal outer edge, which has the advantage of facilitating positioning for various corneal shapes. For example, when a circular guide portion 544 is used as shown in FIG. 25 , the diameter of the guide portion 544 matches the diameter of the cornea, allowing for easy positioning for a cornea of ​​standard diameter. However, when the diameter of the cornea 92 is larger than the diameter of the guide portion 544 as shown in FIG. 25 , the corneal outer edge may be located outside the guide portion 544 and hidden under the peripheral wall of the guide 54, making it difficult to determine whether the measurement start point 546 is located at the corneal outer edge. In contrast, in the guide 54E of Fig. 23 , the linear guide portion 544A does not align with the corneal outer edge. Therefore, as shown in Fig. 24B , even when the corneal diameter is larger than normal, when the measurement starting point 546 is aligned with the corneal outer edge, the corneal outer edge does not deviate from the guide portion 544, making alignment easier. Furthermore, even when the corneal diameter is smaller than normal, as shown in Fig. 24C , the guide 54E can be aligned easily by arranging the guide portion 544A so that it is aligned with the corneal outer edge, as in Figs. 24A and 24B . The guide portions 544 shown in Figs. 23B and 23C can also be aligned in a similar manner. For example, Fig. 24D shows an example in which the guide portion 544 shown in Fig. 23C is in contact with the corneal outer edge at the position of the measurement starting point 546 and is aligned with the corneal outer edge.

[0096] Note that when the guide portion 544A of the guide 54E is positioned in alignment with the outer edge of the cornea, the guide portion 544A is not limited to being in contact with the outer edge of the cornea. For example, as in the above-described example shown in Fig. 14D, when the guide 54E is positioned away from the surface of the eyeball in the radial direction of the eyeball, the guide portion 544A may be positioned so as to overlap with the outer edge of the cornea when viewed in the axial direction of the central axis 90X that passes through the measurement starting point 546 and the eyeball center 99.

[0097] While the guide 54E in FIG. 23 has a measurement starting point 546 on the guide portion 544A, this is not limiting and the measurement starting point may be set at a point other than the tangent point between the guide portion 544 and the corneal periphery. FIG. 26 shows an example of a guide 54F in which a measurement starting point is set at a point other than the tangent point between the guide portion 544 and the corneal periphery. The guide 54F in FIG. 26 has two linear guide portions 544 connected at a predetermined angle, and each guide portion 544 is positioned so that it contacts the corneal periphery at a single point. In this case, the measurement starting point 546 is the point where the line bisecting the interior angle 547 formed by the two guide portions 544 intersects with the corneal periphery, and the guide 54F is configured so that the injection position P1 is located on a line extending the bisector outward from the interior angle 547. That is, the guide 54F and the positioning unit 51 are connected so that the guide portion 544 and the injection position P1 are in the positional relationship shown in FIG. 26 . As a result, the guide 54F is positioned so that each of the two guide portions 544 contacts the corneal periphery at one point, thereby ensuring a predetermined distance LA between the corneal periphery and the injection position P1.

[0098] Fig. 27 is a diagram showing an example of a guide portion 544 that is curved convexly toward the cornea. Although the guide portion 544 in Fig. 27 is curved, it does not have a shape that follows the outer edge of the cornea, and therefore has the advantage of being easy to position for various corneal shapes, similar to the guide 54E in Fig. 23.

[0099] FIG. 28 is a diagram showing an example in which a circular guide portion 544 is arranged to surround injection position P1. A in FIG. 28 schematically shows the positional relationship between the guide portion 544 and injection position P1. The guide portion 544 in FIG. 28 may be, for example, the outer peripheral surface of the positioning portion 51. B in FIG. 28 shows a cross-sectional shape in which the outer peripheral surface of the positioning portion 51 is the guide portion 544. As shown in FIG. 28 , the positioning portion 51 is configured so that the distance from the outer peripheral surface of the positioning portion 51 (intravitreal injection device) to the injection port 77 is a predetermined distance LA. This ensures a predetermined distance LA between the outer peripheral edge of the cornea and injection position P1 when the outer peripheral surface of the positioning portion 51, which is the guide portion 544, is positioned so that it contacts the outer peripheral edge of the cornea. This allows for the realization of an intravitreal injection device with a simple configuration that facilitates intravitreal injection.

[0100] Figure 29 is a diagram showing an example of a guide region 544 that combines straight lines and curved lines. The guide region 544 in Figure 29 has a shape including a straight line portion 544B and a curved line portion 544C. The guide region 544 in Figure 29 is positioned so that the guide region 544 contacts the corneal rim at the measurement start point 546, thereby ensuring a predetermined distance LA between the corneal rim and the injection position P1. Because the guide region 544 in Figure 29 does not have a shape that follows the corneal rim, it has the advantage of being easily positioned for various corneal shapes, similar to the guide region 54E in Figure 23.

[0101] The above describes embodiments of the intravitreal administration device 50 according to the present disclosure, and each aspect disclosed herein can be combined with any other feature disclosed herein.

[0102] DESCRIPTION OF SYMBOLS 1: Syringe 2: Housing 3: Power cable 4: Connector 5: First switch 6: Second switch 7: Socket 10: Syringe assembly 20: Actuator 21: Body 22: Igniter 30: Attachment 40: Piston 50, 50A, 50B, 50C, 50D: Intravitreal injection device 51, 51A, 51B: Positioning portion 52, 52C: Concave and convex portion 53, 53C: Concave and convex portion 54, 54D: Guide 70, 70B: Container 71: Container holder 77: Injection port 80: Plunger

Claims

1. An intravitreal injection device for positioning a needle-free syringe that injects an injection target substance into the vitreous body of an eyeball without using an injection needle, comprising: a guide, at least a portion of which is formed in a shape corresponding to the outer edge of the cornea of ​​the eyeball; and a positioning section connected to the guide and the needle-free syringe, which, when the guide is positioned in line with the outer edge of the cornea, positions an injection outlet of the needle-free syringe from which the injection target substance is injected at a position a predetermined distance behind the eyeball from the outer edge of the cornea.

2. The intravitreal injection device according to claim 1, wherein the needle-free syringe comprises a container having a storage space for storing the injection target substance and having the injection outlet through which the injection target substance is injected into the eyeball, and the positioning unit is attached to the container of the needle-free syringe.

3. The intravitreal injection device according to claim 1, wherein the needle-free syringe comprises a container section having a storage space for storing the injection target substance and having an injection outlet through which the injection target substance is injected into the eyeball, and a holding section for holding the container section, and the positioning section is attached to the holding section of the needle-free syringe.

4. The intravitreal injection device according to claim 1, wherein the guide is formed in a curved shape that follows the outer edge of the cornea.

5. The intravitreal injection device according to claim 4, wherein the positioning portion positions the injection outlet of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the guide is positioned along the outer edge of the cornea.

6. The intravitreal injection device according to claim 1, wherein the guide is formed in a straight line tangent to a portion of the outer edge of the cornea.

7. The intravitreal injection device according to claim 4, wherein the positioning portion positions the injection outlet of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the straight portion of the guide is positioned so as to be aligned along a tangent to the outer edge of the cornea.

8. An intravitreal injection device as described in any one of claims 1 to 7, wherein the positioning portion has an uneven portion on the surface facing the eyeball when the guide is positioned along the outer edge of the cornea, which prevents misalignment.

9. An intravitreal injection device as described in any one of claims 1 to 7, wherein the guide has an uneven portion on the surface facing the eyeball when positioned along the outer edge of the cornea, which prevents misalignment.

10. A needle-free syringe for injecting an injection target substance into the vitreous body of an eyeball without using an injection needle, comprising: a storage unit having a storage space for storing the injection target substance and having an ejection outlet through which the injection target substance is ejected into the eyeball; a drive unit for applying ejection energy for ejecting the injection target substance; and an intravitreal administration tool for determining the injection position of the needle-free syringe relative to the eyeball, wherein the intravitreal administration tool comprises: a guide, at least a portion of which is formed in a shape corresponding to the outer edge of the cornea of ​​the eyeball; and a positioning unit connected to the guide and the needle-free syringe, and which positions the ejection outlet at a position a predetermined distance behind the eyeball from the outer edge of the cornea when the guide is positioned in accordance with the outer edge of the cornea.

11. The needle-free injector according to claim 10, wherein the positioning portion of the intravitreal injection device is attached to the housing portion.

12. The needle-free syringe according to claim 10, further comprising a holding portion for holding the container portion, and the positioning portion of the intravitreal injection device is attached to the holding portion.

13. The needle-free injector according to claim 10, wherein the guide is formed in a curve that follows the outer edge of the cornea.

14. The needle-free syringe according to claim 13, wherein the positioning unit positions the injection outlet of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the guide is placed along the outer edge of the cornea.

15. The needle-free injector according to claim 10, wherein the guide is formed in a straight line tangent to a portion of the outer edge of the cornea.

16. The needle-free syringe according to claim 15, wherein the positioning section positions the injection outlet of the needle-free syringe at a position 3.5 mm to 4.0 mm away from the outer edge of the cornea when the straight portion of the guide is positioned so as to follow a tangent to the outer edge of the cornea.

17. The needle-free syringe according to any one of claims 10 to 16, wherein the positioning portion has an uneven portion on the surface facing the eyeball when the guide is positioned along the outer edge of the cornea, which prevents the guide from shifting out of position.

18. The needle-free syringe according to any one of claims 10 to 16, wherein the guide has an uneven portion on the surface facing the eyeball when placed along the outer edge of the cornea, for preventing misalignment.

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