JP2020121043A - Soft intraocular lens - Google Patents

Abstract

To provide a soft intraocular lens provided with strength and flexibility appropriate for insertion due to an injector and shape recovery with good balance.SOLUTION: A soft intraocular lens 1 provided by the present invention is made of a copolymer of a polymerizable monomer component having acrylic acid ester and methacrylic acid ester as a main component. The monomer component contains at a ratio of 42 mass% or larger and 62 mass% or smaller of phenoxy ethyl acrylate, 35 mass% or larger and 55 mass% or smaller of n-butyl methacrylate, and 3 mass% or larger and 10 mass% or smaller of methyl methacrylate.SELECTED DRAWING: Figure 4

Description

The present invention relates to soft intraocular lenses.

2. Description of the Related Art Conventionally, a treatment method of inserting a soft lens (intraocular lens: IOL) into the eyeball has been widely adopted for the purpose of treating cataracts and correcting myopia and astigmatism. This soft intraocular lens typically includes an optical section that exhibits a refractive power and a support section that fixes the position of the optical section within the eyeball. When inserting the intraocular lens, for example, a one-piece type intraocular lens in which the optical part and the support part are integrally molded is prepared, and the intraocular lens is folded using an insertion instrument called an injector. Insert into the sac. The inserted intraocular lens restores its original shape again in the capsule and presses the support portion against the capsule to stabilize the position in the capsule. As an example of a conventional technique relating to such a soft intraocular lens, Patent Document 1 is cited.

JP, 2002-017845, A

By the way, the soft intraocular lens is inserted into the capsule of the eyeball through an incision formed in the cornea. In recent years, the size of this incision has been reduced to about 2 mm, and intraocular lenses are required to have high flexibility and shape recovery so that they can be folded smaller than ever before. However, in the conventional soft intraocular lens, there is room for improvement in such a balance between flexibility and shape recoverability and strength withstanding pressing by the injector.

The present application has been made in view of the above circumstances of the related art, and an object of the present application is to provide a soft intraocular lens that has a good balance of strength, flexibility, and shape recovery suitable for insertion by an injector.

The soft intraocular lens provided by the technique disclosed herein is composed of a copolymer of polymerizable monomer components containing acrylic acid ester and methacrylic acid ester as main components. And the said monomer component is phenoxyethyl acrylate 42 mass% or more and 62 mass% or less, n-butylmethacrylate 35 mass% or more and 55 mass% or less, and methylmethacrylate 3 mass% or more and 10 mass% or less in the ratio. Including.

For example, the soft intraocular lens described in Patent Document 1 is easy to fold in the injector and has excellent flexibility to recover the shape in a short time after being inserted into the capsule. However, in order to insert the lens into the eye through a smaller incision, the soft intraocular lens has the property of maintaining a smaller folded state within the injector, and releasing rapidly after being inserted into the eye. It is useful to be prepared. Further, it is required that the lens should not be damaged by the contact of the injector with the plunger even when the lens is folded into a smaller size. According to the intraocular lens having the above configuration, flexibility such as folding is maintained, and resistance such as strength (for example, breaking strength) and rubber elasticity are improved. Accordingly, it is possible to realize a soft intraocular lens in which proper strength and shape recovery suitable for insertion into the capsule by an injector are realized in a well-balanced manner.

In a preferred embodiment of the soft intraocular lens disclosed herein, the monomer component may further following _{formula: CH 2 = CH-COO-} R 1; 10 wt% or more 1 wt% of the monomer component represented by the following Included in the ratio. However, R ₁ in the formula is a linear, branched or cyclic functional group having 2 to 8 carbon atoms. With such a configuration, the composition of the monomer component can be made flexible, and a soft intraocular lens having the above characteristics can be manufactured.

In a preferred embodiment of the soft intraocular lens disclosed herein, the international rubber hardness is 30 or more and 40 or less. Since the soft intraocular lens having the above composition has such a rubber hardness, it is possible to realize a soft intraocular lens which is flexible but has an appropriate rubber hardness. As a result, for example, a soft intraocular lens whose expansion is suppressed during the injection from the injector and which is quickly recovered after the injection is realized.

In a preferred embodiment of the soft intraocular lens disclosed herein, when molded to have a diameter of 6 mm and a power of 30 D, the load required to bend the diametrical direction so that the diametrical distance is 3 mm. Is 2N or less. Lenses containing methyl methacrylate (MMA) tend to be uniformly rigid. However, by copolymerizing the monomer components having the above composition, the breaking strength can be increased without becoming too brittle, and the resin can be easily bent without generating cracks with a small load.

It is a (a) top view and a (b) side view which explain typically composition of a one piece type soft intraocular lens concerning one embodiment. It is a mimetic diagram explaining behavior (a)-(c) at the time of ejection by an injector of a soft intraocular lens concerning one embodiment. It is a graph which shows the relationship between the content of the MMA component which concerns on the soft intraocular lens material of each example, and the glass transition point (Tg). It is a graph which shows the relationship between the load and elongation concerning the soft intraocular lens material of each example. (A) (b) is a schematic diagram explaining the bending test method of a soft intraocular lens. It is a graph which shows the bending load of the soft intraocular lens of each example by a bending test.

Hereinafter, preferred embodiments of the present invention will be described. Incidentally, matters other than matters particularly referred to in the present specification (monomer composition and physical properties of the soft intraocular lens, etc.) and matters necessary for carrying out the present invention (such as shape and manufacturing method of the soft intraocular lens). (General matters) can be understood by those skilled in the art based on the teaching about the practice of the invention described in this specification and the common general knowledge as of the filing. The present invention can be implemented based on the contents disclosed in this specification and the common general technical knowledge in the field. Further, the notation “A to B” indicating a numerical range means “A or more and B or less” unless otherwise specified.

FIG. 1 is a diagram illustrating a configuration of a one-piece type soft intraocular lens 1 according to an embodiment. 1A is a plan view of the soft intraocular lens 1, and FIG. 1B is a side view thereof. The soft intraocular lens 1 includes an optical section 10 having a predetermined refractive power, and a pair of support sections 20 for supporting the optical section 10 in the eyeball. The optical part 10 and the support part 20 of this example are integrally molded from the same raw material resin composition.

The optical unit 10 has, for example, a circular shape having a diameter D of about 5.5 mm to 7 mm, typically about 6 mm in a plan view. The direction orthogonal to the diameter D direction of the optical unit 10 is called the thickness direction. The optical unit 10 has a biconvex lens shape that protrudes toward both sides (both sides in the thickness direction), for example, in a side view. The thickness and surface shape of the optical unit 10 can be determined based on the refractive index of the material forming the optical unit 10 and the desired refractive power (optical action) required for the optical unit 10. The thickness of the optical portion 10 is, for example, 300 μm or more, 400 μm or more as an example, and 800 μm or less, 700 μm or less as an example, typically about 600 μm (about ±10%) at the center O of the circular optical portion 10. ). However, the shape of the optical unit 10 is not limited to this. The shape of the optical unit 10 may be, for example, an elliptical shape or a similar elliptical shape in a plan view. Further, the shape of the optical unit 10 may be, for example, a plano-convex lens shape in which only one surface is projected and the other surface is flat in a side view, or one surface is projected and the other surface is concave. It may have a meniscus lens shape or the like.

The support portion 20 is formed so as to project outward from the peripheral edge of the optical portion 10. The pair of support portions 20 are formed with respect to the optical portion 10 so as to be point-symmetrical with the center O of the optical portion 10 as the axis of symmetry. The support portion 20 has a loop shape with one end free. The supporting portions 20 each include a bent portion 20a that is largely bent in the plane of the lens portion in the vicinity of the connection portion with the optical portion 10. The support portion 20 is configured to be further bendable in the direction in which the free end portion is closer to the center O in the bent portion 20a. The distance (maximum dimension) L between the free ends of the pair of support portions 20 is, for example, about 11.5 mm to 13.5 mm, and typically about 12 mm to 13 mm. However, the shape of the support portion 20 is not limited to this. The optical unit 10 and the support unit 20 may be made of the same material or may be made of different materials. In the soft intraocular lens 1 disclosed herein, for example, both the optical section 10 and the support section 20 may be made of the same soft intraocular lens material.

Such a soft intraocular lens 1 is inserted into the eye using an intraocular lens inserter called an injector 50 as shown in FIG. 2, for example. Here, in general, the soft intraocular lens 1 is mounted on the injector 50 while being mounted on the cartridge 60. The injector 50 has a configuration similar to that of a syringe, and includes, for example, a cylindrical injector body 52, a cartridge mounting portion 54 provided at the tip of the injector body 52, and a cartridge 60 that can be inserted into the injector body 52 and loaded into the cartridge 60. And a plunger 56 for pushing out the soft intraocular lens 1 thus formed. Further, the cartridge 60 has a substantially horn-shaped ejection port (nozzle) 62 for curving and folding the soft intraocular lens 1 pushed in the cylindrical axis direction by the plunger 56 and ejecting from the cartridge 60 in the folded shape. I have it.

When inserting the soft intraocular lens 1 into the eye, first, the cartridge 60 in which the soft intraocular lens 1 is mounted is mounted on the cartridge mounting portion 54 of the injector 50. Then, if necessary, a lubricant for smoothing the movement of the soft intraocular lens 1 in the cartridge 60 is supplied to the inside of the cartridge 60, and then the injector body 52 is held and the injection port 62 is inserted from the incision into the capsule. insert. Then, the plunger 56 is slowly inserted into the injector main body 52 (or rotated by a screw), and the soft intraocular lens 1 is pushed by the plunger 56 into the ejection opening 62, and the soft intraocular lens 1 is ejected inside the ejection opening 62. Fold. Subsequently, by slowly inserting the plunger 56, the folded soft intraocular lens 1 can be ejected from the ejection port 62 into the capsule. When the soft intraocular lens 1 is completely pushed out, the injector main body 52 is held and the injection port 62 is pulled out from the capsule. The soft intraocular lens 1 inserted into the capsule slowly recovers from the folded state to the original disc shape. The support portion 20 of the soft intraocular lens 1 is sufficiently extended and pressed against the peripheral edge of the capsule, so that the position of the optical portion 10 is appropriately adjusted within the capsule. This allows the soft intraocular lens 1 to be properly inserted into the eyeball.

Here, the soft intraocular lens is made of a copolymer obtained by copolymerizing a polymerizable monomer component. The monomer component for forming the soft intraocular lens is mainly composed of acrylic acid ester and methacrylic acid ester. Here, the main component means that the total amount of acrylic acid ester and methacrylic acid ester is 85% by mass or more when the total amount of the monomer components for forming the soft intraocular lens is 100% by mass. .. The total amount of acrylic acid ester and methacrylic acid ester is preferably 90% by mass or more, and may be 95% by mass or more.

And the soft intraocular lens which concerns on this technique WHEREIN: (A) Phenoxyethyl acrylate (Ethylene Glycol Monophenyl Ether Acrylate: EGPEA) 42 mass% or more and 62 mass% or less, (B) n-butylmethacrylate ( Butyl methacrylate: BMA) is contained in an amount of 35% by mass or more and 55% by mass or less, and (C) methyl methacrylate (MMA) in a ratio of 3% by mass or more and 10% by mass or less.

Since phenoxyethyl acrylate has an aromatic ring in its molecular structure, it can realize a high refractive index required for an intraocular lens. In addition, phenoxyethyl acrylate has a function of lowering the Tg of the copolymer, and can impart flexibility to the soft intraocular lens in the room temperature region, for example. In particular, phenoxyethyl acrylate can be expressed without losing its flexibility even when it is combined with MMA together with BMA described below to form a copolymer. From this point of view, the soft intraocular lens disclosed herein uses phenoxyethyl acrylate as one of the main monomer components.

The proportion of phenoxyethyl acrylate in all the monomer components is preferably 40% by mass or more from the viewpoint of imparting a high refractive index to the soft intraocular lens and sufficiently lowering Tg. The phenoxyethyl acrylate is preferably 45% by mass or more, more preferably 47% by mass or more, for example, 50% by mass or more. However, when the proportion of phenoxyethyl acrylate exceeds 62% by mass, the glass transition point of the obtained intraocular lens is lowered, but the repulsive force against bending becomes too strong, which is not preferable. The proportion of phenoxyethyl acrylate is preferably 57% by mass or less, more preferably 55% by mass or less, for example, 54% by mass or less, or 53% by mass or less.

n-Butyl methacrylate can impart appropriate hardness to a copolymer containing a large amount of phenoxyethyl acrylate. From this point of view, the soft intraocular lens disclosed herein uses n-butyl methacrylate as one of the main monomer components. The proportion of n-butyl methacrylate in all the monomer components may be 35% by mass or more, preferably 36% by mass or more, and more preferably 37% by mass or more. However, if the proportion of n-butyl methacrylate exceeds 55% by mass, the intraocular lens becomes brittle and cracks are likely to occur in the peripheral portion of the optical portion, which is not preferable. The proportion of n-butyl methacrylate depends on, for example, the proportion of methyl methacrylate described later, but is typically 50% by mass or less, preferably 45% by mass or less, more preferably 40% by mass or less, for example, 39% by mass or less. It may be less than or equal to mass %.

Methyl methacrylate is generally known as a raw material for hard lenses, and has a small molecular weight, so that it effectively increases Tg, and has actions such as a decrease in tackiness in a polymer, a marked increase in hardness and strength, and a decrease in ductility. However, although details are not clear, in the soft intraocular lens disclosed herein, MMA is added to the copolymer containing a large amount of phenoxyethyl acrylate in a specific ratio to improve its flexibility. It has been clarified that the previously unknown mechanical properties such as ductility, tensile strength, and rubber elasticity can be effectively expressed while maintaining. In other words, the intraocular lens can improve its toughness and spreadability without exhibiting brittleness. Methyl methacrylate can exhibit the above effect even when contained in a small amount. Therefore, the proportion of methyl methacrylate in all the monomer components may be more than 0% by weight, but from the viewpoint of realizing a soft intraocular lens having characteristics suitable for injection by an injector, for example, 3% by weight The above is recommended. The proportion of methyl methacrylate is preferably 4% by mass or more, more preferably 5% by mass or more, and may be, for example, 6% by mass or more. However, the inclusion of a small amount of methyl methacrylate has a great influence on the properties of the copolymer, and the hardness of the obtained intraocular lens is too high, which is not preferable. The proportion of methyl methacrylate is appropriately 10 mass% or less, for example, preferably 8 mass% or less, and more preferably 7 mass% or less.

The soft intraocular lens 1 disclosed herein contains (A) phenoxyethyl acrylate, (B) n-butyl methacrylate, and (C) methyl methacrylate in the balance as described above, and thereby has strength, flexibility and shape. The recoverability can be provided in a well-balanced manner. As a result, the soft intraocular lens 1 can be smoothly bent by the injector 50, and while maintaining its folded shape when ejected from the injector 50, is quickly released when completely ejected into the eye. .. With such a behavior, the soft intraocular lens 1 can be smoothly inserted without damaging the incision of the eyeball. Further, the time until the shape of the soft intraocular lens 1 is recovered after the insertion is shortened, so that the stress can be reduced and the soft intraocular lens 1 can be inserted into the eyeball.

In addition to the above-mentioned (A) to (C), the monomer component may further contain another acrylic monomer component different from (A) to (C). Examples of such other acrylic monomer are represented by the following formula: CH ₂ ═CH—COO—R ₁ ; R ₁ is a linear, branched or cyclic functional group having 2 to 8 carbon atoms. And a monomer that is Specific examples of such other acrylates include ethyl acrylate, propyl acrylate, n-butyl acrylate, tert-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, tert-pentyl acrylate and hexyl acrylate. , Linear alkyl acrylates such as 2-methylbutyl acrylate, heptyl acrylate and octyl acrylate, cyclic alkyl acrylates such as cyclopentyl acrylate and cyclohexyl acrylate, aromatic rings such as phenyl acrylate and 2-phenylethyl acrylate Examples include contained acrylates and the like. These acrylic monomer components may contain any one kind alone, or may contain two or more kinds in combination.

By including even a small amount of other acrylic monomers, the composition of the monomer components (A) to (C) can be flexibly changed. For example, by including n-butyl acrylate as another acrylic monomer component, the action of (C) methyl methacrylate can be appropriately mitigated, and for example, the hardness increase due to (C) methyl methacrylate can be suppressed and flexibility can be improved. Can be maintained. Further, for example, by including phenyl acrylate as another acrylic monomer component, the proportion of (A) phenoxyethyl acrylate can be relatively reduced. The proportion of such other acrylate cannot be unequivocally determined because it depends on the balance of the monomer components (A) to (C), but it may be contained in an amount of more than 0% by mass, preferably 1% by mass. % Or more, more preferably 2% by mass or more, for example, 3% by mass or more. Excessive inclusion of other acrylic monomer components is not preferable because it may impair the characteristics of the intraocular lens 1 disclosed herein. The proportion of the other acrylic monomer component is, for example, suitably 10% by mass or less, preferably 7% by mass or less, and more preferably 5% by mass or less. For example, this soft intraocular lens does not contain a monomer component (A) to (C) and a polymerizable monomer component other than the above-mentioned other acrylic monomer component, in addition to the additive component described later. You may For example, as an example, it may be a copolymer of a monomer component consisting only of (A) EGPEA, (B) BMA, (C) MMA, and BA and an additive component described below. Further, the soft intraocular lens disclosed herein may be configured not to include the hydrophilic monomer component.

The soft intraocular lens can include components (additive components) known as constituent raw materials for this type of soft intraocular lens, in addition to the above-described polymerizable monomer component. Such additive components are a cross-linking agent, a polymerization initiator, an ultraviolet absorber, a colorant and the like.

The cross-linking agent connects and cures the above-mentioned polymerizable monomer components. As the cross-linking agent, a polymerizable monomer component having cross-linking property can be preferably used. For example, cross-linking (meth)acrylate can be used without particular limitation. Here, (meth)acrylate is a term that includes acrylate and methacrylate. The crosslinkable (meth)acrylate may be a bifunctional (meth)acrylate or a trifunctional or higher-functional polyfunctional (meth)acrylate, and specifically, for example, 1,3-butylene glycol di(meth)acrylate. 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene Glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, ethylene oxide modified bisphenol A di(meth)acrylate, propylene glycol di(meth)acrylate , Dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate and other bifunctional (meth)acrylates, trimethylolpropane tri(meth)acrylate, tris(2-acryloyloxyethyl)isocyanurate, ethylene oxide Examples include trifunctional (meth)acrylates such as modified trimethylolpropane tri(meth)acrylate. Among them, it is preferable to use any one of 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Although not limited to this, the ratio of the crosslinkable (meth)acrylate is about 1% by mass or more and about 10% by mass or less when the total amount of the monomer components is 100% by mass. Good to do.

Further, as the polymerization initiator, for example, a radical polymerization initiator composed of benzoin ethers or amines can be preferably used. As an example, specifically, a polymerization initiator represented by 2,2-azobisisobutyronitrile, azobisdimethylvaleronitrile, benzoin, methylorthobenzoylbenzoate, or the like can be used. The amount of these can be appropriately determined from the relationship with the above-mentioned polymerizable monomer component. For example, it may be contained in an amount of about 0.01 to 1 part by mass with respect to 100 parts by mass of the polymerizable monomer component.

The ultraviolet absorber may include a monomer component having an ultraviolet absorbing ability. The crystalline lens has a property of not easily transmitting ultraviolet rays, whereas the soft intraocular lens can transmit ultraviolet rays, and thus there is a risk of damaging the retina. Therefore, by containing an ultraviolet-absorbing monomer component having an ultraviolet-absorbing ability, the ultraviolet-absorbing ability can be imparted to the copolymer constituting the soft intraocular lens. This makes it possible to suppress damage to the retina and reduce the risk of UV-induced eye diseases such as macular degeneration. In addition, "a monomer having an ultraviolet ray absorbing ability" means all monomers having a functional group having an ultraviolet ray absorbing ability. Further, the functional group having an ultraviolet absorbing ability means a group of functional atomic groups having an absorption spectrum in the ultraviolet region. Such a functional group having an ultraviolet absorbing ability may be a generic term for an alkyl residue, a carboxylic acid residue, an alcohol residue, an amino residue, an acyl group, etc. of an ultraviolet absorbing compound widely used as an ultraviolet absorber. In one example, the ultraviolet absorbing functional group widely includes an atomic group obtained by removing a hydrogen atom from a carboxyl group, a hydroxyl group, an amino group, etc. in an ultraviolet absorbing compound, an acyl group in an ultraviolet absorbing compound, and the like. More specifically, a benzotriazole-based monomer component, a benzophenone-based monomer component, a salicylic acid-based monomer component, and a cyanoacrylate-based monomer component can be preferably used as the ultraviolet absorbing monomer component.

It is considered appropriate that the ultraviolet-absorbing monomer component is contained in a proportion of about 0.1 to 1 part by mass when the total amount of the polymerizing components is 100 parts by mass. This is because if the proportion of the ultraviolet ray absorbing monomer component is less than 0.1% by mass, the ultraviolet ray absorbing ability of the soft intraocular lens may be too low to effectively function. If the proportion of the ultraviolet absorbing monomer component is more than 1% by mass, the soft intraocular lens may be discolored due to a change in physical properties, a change with time, or the like. The proportion of the UV-absorbing monomer component is typically about 0.15 to 0.7% by mass, and more preferably about 0.2 to 0.5% by mass.

Further, since the crystalline lens is yellowish, it has a property of partially suppressing transmission of blue light, which is the opposite color. Therefore, it is preferable that the soft intraocular lens disclosed herein is also colored with a yellow pigment, a red pigment, or the like to adjust the color vision. As such a colorant, a known azo compound, pyrazole compound or the like used as a colorant for this type of soft intraocular lens can be appropriately used. The amount of these can be appropriately determined from the relationship with the above-mentioned polymerizable monomer component. For example, it can be contained in an amount of about 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the polymerizable monomer component.

The method for producing the soft intraocular lens 1 is not particularly limited, and a known method for synthesizing a (meth)acrylate copolymer such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or a photopolymerization method. Various polymerization methods known as can be appropriately adopted. Among them, for example, a solution polymerization method in which a mixed monomer composition in which the above-mentioned polymerization components are appropriately mixed is polymerized can be preferably used. For molding the soft intraocular lens 1, conventionally known molding methods such as a so-called cast molding method and lathe cutting method can be appropriately adopted. For example, in the cast mold manufacturing method, specifically, a mold provided with a cavity (void) corresponding to the shape of the target soft intraocular lens 1 is prepared, and the raw material composition (raw material monomer solution) is supplied to this mold. The raw material composition may be polymerized in the mold. Further, for example, in the cutting method, specifically, the mixed monomer composition corresponding to the composition of the target soft intraocular lens 1 is polymerized into a sheet shape (including a plate shape), and the polymerized sheet-shaped soft eye is used. By cutting the inner lens material, the soft intraocular lens 1 having a desired shape may be processed. The cutting may be performed by freezing a sheet-shaped soft intraocular lens material. The soft intraocular lens 1 has various shapes, and the cutting process can be performed by various processes. From such a viewpoint, the soft intraocular lens 1 disclosed herein can be understood to include a soft intraocular lens (that is, a soft intraocular lens material) that does not have a desired final shape. For example, the soft intraocular lens 1 disclosed herein can also include a sheet-shaped soft intraocular lens material before cutting.

The above-described soft intraocular lens 1 disclosed here is configured so that the insertion into the eyeball by the injector 50 can be performed particularly preferably. Therefore, strength is improved by overcoming brittleness while maintaining high flexibility. In addition, the soft intraocular lens 1 maintains the folded shape even if a force that holds the folded shape is exerted even by a part of the ejection opening 62, and quickly recovers the shape when the holding force by the ejection opening 62 is canceled. To do. This makes it possible to reduce the contact resistance between the soft intraocular lens 1 and the exit port 62 at the time of injection, and it is possible to suppress interference with the cut wound due to early recovery of the soft intraocular lens 1. The properties of such a soft intraocular lens material can be suitably realized, for example, with an international rubber hardness of 30 or more and 40 or less. Accordingly, even when the plunger 56 of the injector 50 presses the book meat portion on the peripheral edge of the optical unit 10, breakage or damage can be suppressed without cracking or the like in the pressing portion.

The soft intraocular lens material disclosed herein also has improved tensile strength. As a result, even when the plunger 56 locally presses the book-filling portion on the periphery of the optical unit 10 as described above, the pressing portion is stretched, and breakage or damage is suitably suppressed. Such tensile strength can be confirmed by, for example, the tensile breaking strength and the breaking elongation being improved as compared with a soft intraocular lens containing no MMA. As an example, a known composition obtained by copolymerizing a monomer component containing (A) EGPEA in an amount of 53.9 parts by mass, BMA in an amount of 39.7 parts by mass, BA in an amount of 4.0 parts by mass, and not including MMA. Compared with a soft intraocular lens, tensile breaking strength is improved by 120% or more (preferably 150% or more, more preferably 180% or more), and breaking elongation is 110% or more (preferably 115% or more, more Preferably 120% or more).

As a result, the soft intraocular lens 1 disclosed herein has an appropriately shortened recovery time after being ejected from the injector 50. That is, the soft intraocular lens 1 maintains the folded shape and suppresses recovery while the force for holding the folded shape by the ejection opening 62 of the cartridge 60 is acting, but the holding force by the ejection opening 62 is eliminated. When it is done, the shape is recovered promptly. As a result, the recovery time from when the soft intraocular lens 1 is completely ejected from the injector 50 to when the folded shape is completely recovered is, for example, about 30 to 60 seconds (preferably about 30 to 50 seconds). Has been adjusted to 2 seconds). Accordingly, the soft intraocular lens 1 is excessively flexible, and the soft intraocular lens 1 or the incision can be smoothly inserted into the eyeball when being ejected from the injector 50 without being damaged.

Hereinafter, some embodiments of the present technology will be described, but the present technology is not intended to be limited to the specific examples.

[Test Example 1]
As a polymerization component, the following polymerizable monomers were prepared in a composition shown in Table 1, and a cross-linking agent, an ultraviolet absorber and a polymerization initiator were added and mixed uniformly to give a raw material composition for intraocular lenses of Examples 1 to 4. I prepared things. Then, this raw material composition was poured into a reactor and polymerized under the conditions of 60° C. for 12 hours and 100° C. for 12 hours to obtain samples for evaluation of intraocular lenses of Examples 1 to 4.

The following four types were used as the polymerizable monomer. Further, 1,4-butanediol diacrylate (BDDA) is used as a cross-linking agent, and 2-(2′-hydroxy-5′-methacrylyloxypropyl-3′-tert-butylphenyl)-5 is used as an ultraviolet absorber. -Chloro-2H-benzotriazole (UV-X) was used, and 2,2-azobisisobutyronitrile (AIBN) was used as a polymerization initiator.
EGPEA: ethylene glycol monophenyl ether acrylate BMA: n-butyl methacrylate BA: n-butyl acrylate MMA: methyl methacrylate

[Basic characteristics]
The refractive index and the glass transition point (Tg) of the evaluation sample of each example were measured. The refractive index was measured at room temperature (23° C.) using a digital refractometer (RX-7000i, manufactured by Atago Co., Ltd.). The glass transition point was determined by thermal analysis using a differential scanning calorimeter (DSC6220, manufactured by SII Nanotechnology Inc.) with the measurement temperature in the range of -50°C to 200°C. The results are shown in the columns of "Refractive index" and "Tg" in Table 1 below and FIG. However, FIG. 3 also shows data for samples in which the amount of MMA was changed to a formulation other than Examples 1 to 4.

[Tensile test]
The tensile properties of the evaluation samples of each example were examined as an index for evaluating the flexibility during bending. Specifically, a test piece was cut out from the evaluation sample of each example, and a tensile test was carried out according to JIS K7161:2014 to determine the tensile load-elongation property until the test piece broke. As a test piece, a dumbbell-type test piece in which a tab portion at both ends has a width of 10 mm, a central parallel portion has a width of 5 mm, a parallel portion has a length of 25 mm, and a shoulder portion has a linear shape from a sheet having a thickness of 3 mm Prepared. As a tensile tester, a multipurpose material tester manufactured by Imoto Machinery Co., Ltd. was used, and a test was performed under an environment of 23 to 25° C. under the conditions of a distance between marked lines of 25 mm, a test speed of 100 mm/min, and N=4. As a result, the obtained elongation-stress characteristics (representative) are shown in FIG. Further, the breaking strength, the maximum elongation, and the breaking elongation (elongation at the time of tensile breaking) were calculated from the tensile stress-strain characteristics, and "breaking strength", "maximum elongation", and "breaking elongation" in Table 1 below. Are shown in each column. The breaking strength is a value obtained by dividing the load at break of the test piece by the cross-sectional area between the marked lines of the test piece before the test, and corresponds to the tensile breaking stress. The maximum elongation is the maximum amount of change in the distance between the marked lines of the dumbbell-shaped tensile test piece fixed to the chuck of the tensile tester. The breaking elongation is a value in which the increase amount (=maximum elongation) of the distance between marked lines at the time of breaking the test piece is expressed as a ratio (%) to the distance between marked lines before the test.

[Lens bending test]
The evaluation sample of each example was frozen and cut to form the optical part of the intraocular lens to prepare the evaluation lens. The bending hardness of this evaluation lens was examined by measuring the load required for bending a predetermined amount. As for the bending load, as shown in FIG. 5(a), a table compression tester is used to apply a load in the diameter direction of the optical part of the lens molded body to bend the lens into a U-shaped cross section, and (b). As shown in, the load was measured when the distance between the diametrical ends was 3 mm. In addition, as for the evaluation lens, three kinds were prepared in each example so that the diameter of the optical part was 6 mm and the dioptric power was 10 D, 20 D, and 30 D according to the refractive index measured above. The measurement result of the bending load of each evaluation lens is shown in FIG. In addition, the bending load for the 20D lens out of the three powers is shown in the "Bending hardness" column of Table 1 below.

[Evaluation]
As shown in Table 1 and FIG. 3, it was found that the Tg and the refractive index of the intraocular lens evaluation sample of each example changed substantially in accordance with the ratio of MMA. When the ratio of MMA was in the range of 0 to 20% by mass, the refractive index of all the evaluation samples was in the range of 1.514 to 1.519, and it was confirmed that the value was appropriate as an intraocular lens material. Regarding the glass transition point, it was confirmed that the Tg of all the evaluation samples was sufficiently lower than the human body temperature. However, in order for the intraocular lens to stably exhibit flexibility near room temperature, Tg is preferably about 15° C. or less, and therefore it can be said that the MMA amount is preferably less than 13% by mass.

It was also found that the content of MMA has a great influence on the tensile elongation characteristics of each sample. As shown in FIG. 4, it was found that in the sample containing MMA, the stretchability of the sample containing MMA was significantly increased depending on the amount of MMA added, as compared with the sample of Example 1 containing no MMA. As known as a raw material for hard lenses, MMA has the effect of increasing the hardness and strength of lens materials. It was confirmed that the breaking strength, the maximum elongation, and the breaking elongation were all significantly increased by adding MMA even in a small amount. Although not specifically shown, it was found that the elastic modulus (the slope of the load-elongation curve at the time of elastic deformation) of the sample of each example can be greatly changed depending on the content of MMA. Here, the elastic modulus of the lens material is related to the load for bending the lens when the lens is ejected from the injector. The higher the modulus of elasticity of the lens, the more force is required to push the plunger of the injector. From the load-elongation curve at the time of elastic deformation in FIG. 4, the sample of Example 2 has the breaking strength and the like increased while the shape of the load-elongation curve is almost the same as that of the sample of Example 1, whereas Example 3 It was found that the samples of Example 4 and Example 4 greatly changed from the slope of the load-elongation curve during elastic deformation. In order to smoothly carry out the injection of the intraocular lens by the injector, it can be said that the MMA amount should be smaller than 13% by mass of Example 3.

As shown in Table 1 and FIG. 6, it was found that the content of MMA significantly affects the bending properties of the intraocular lens molded body. As can be seen from the results of the above tensile test, each of the evaluation samples of each example had sufficient flexibility. Therefore, it was confirmed that all intraocular lens molded bodies were stably deformed into a U shape without buckling or unintended deformation during the bending test. The load required for bending at this time resulted in a great difference depending on the frequency (thickness) of the intraocular lens molded body and the MMA content. In the operation of ejecting the intraocular lens from the injector, considering the load with which the operator can bend the lens without stress, the bending load is preferably about 2N or less. In the case of Example 3 in which the content of MMA is 13% by mass, the content of MMA is more than 13% by mass in order to obtain an intraocular lens that can be stably bent with a light force regardless of the power of the intraocular lens. It can be said that it is preferable to reduce the amount.

[Test Example 2]
As a polymerization component, the following polymerizable monomers were prepared in the formulations shown in Table 2, and a crosslinking agent, a UV absorber, a polymerization initiator and a colorant were added and mixed uniformly to give Examples 2-1 to 2-6. A raw material composition for an intraocular lens was prepared. Then, this raw material composition was poured into a reactor and polymerized under the conditions of 60° C. for 12 hours and 100° C. for 12 hours to obtain samples for evaluation of intraocular lenses of Examples 2-1 to 2-6. It was The same compounds as in Test Example 1 were used as the polymerizable monomer, the cross-linking agent, the ultraviolet absorber and the polymerization initiator. Further, as the colorant, a yellow dye and a red dye used for coloring this type of intraocular lens are used in combination, and the total amount thereof is less than 0.01% by mass. Not not. In addition, in the example 2-1 and the example 2-3 in the test example 2, the blending of four kinds of polymerizable monomers corresponds to the example 1 and the example 2 of the test example 1, respectively.

[Rubber hardness]
The international rubber hardness (IRHD) was measured for the evaluation sample of each example. Specifically, a 1.5 cm square test piece was cut out from the evaluation sample, and the planar hardness was measured according to the M method (medium size micro size test) of ISO48:2010 (JIS K6253-2). .. As the durometer, GS-680sel manufactured by Teclock Co., Ltd. (Type A durometer specified in JIS K6253:2012) is used, and the test piece is tested under the test environment of temperature: 21 to 23° C. and humidity: 30 to 70% RH. After acclimatizing for 1 hour or more, the rubber hardness was measured with the number of tests: n=5. An arithmetic mean value was calculated from the obtained international rubber hardness and is shown in the "IRHD" column of Table 2 below. Note that IRHD has a lower limit of "30", and hardness less than IRHD30 cannot be measured, and thus is indicated as "ND".

[Evaluation of tensile properties]
A tensile test was performed on the evaluation sample of each example in accordance with JIS K7161:2014. Specifically, by pouring the raw material composition prepared above into a mold for strip test pieces and polymerizing under the same conditions, strip-shaped test pieces having a thickness of 1.2 mm, a width of 12 mm, and a length of 75 mm. Got As the tensile tester, a tabletop precision universal tester (AGS-50NX) manufactured by Shimadzu Corporation was used. Then, the prepared test piece was conditioned for 1 hour or more in a test environment of a temperature of 21 to 23° C. and a humidity of 30 to 70% RH, and then a tensile test was performed at a gauge distance of 15 mm and a test speed of 100 mm/min. The tensile load-elongation property until breakage was determined. Then, the breaking strength and the breaking elongation were calculated from the results of this tensile test, and they are shown in the columns of "breaking strength" and "breaking elongation" in Table 2 below.

[Evaluation]
As shown in Examples 2-1 to 2-5 in Table 2, it was confirmed that the IRHD tends to increase as the MMA content increases. It is considered that this is due to the conventionally known high hardness property of MMA. If the IRHD is less than 30, the rubber elasticity when forming the intraocular lens may be too weak, and for example, the peripheral portion of the thin lens may be damaged when pressed by the plunger in the injector. Therefore, IRHD is preferably 30 or more. However, if the IRHD is too high, the resistance at the time of rolling the intraocular lens in the injector becomes high, which may deteriorate the operability. Therefore, IRHD is preferably about 40 or less.

Regarding the tensile properties, the load-elongation characteristics of the test pieces of Examples 2-2 to 2-4 show the same curve as that of Example 2-1, but the elongation increases as the MMA content increases, and the breaking strength increases. It was found that both the fracture elongation and the elongation at break became high. However, as shown in Example 2-5, it was found that when the MMA content was 13% by mass in excess, both the breaking strength and the breaking elongation decreased depending on the balance with other monomer components. From the results of the tensile test, it is considered that when the MMA content becomes excessive, the polymerization state (solidification method) itself may change. From these things, it is preferable that the content of MMA does not exceed 13% by mass. Further, as can be seen from the comparison between Example 2-3 and Example 2-6, even if the amount of BMA, which is a methacrylate, is increased instead of containing MMA, the IRHD, the breaking strength and the breaking elongation are increased. I knew it wasn't. It has been found that it is effective that the acrylate to be added has a short carbon chain like MMA.

[Test Example 3]
Evaluation lenses were prepared from the evaluation samples of Example 1 and Example 2 of Test Example 1, and the recovery time from the folded state was measured. Specifically, each evaluation sample was frozen and cut to prepare a one-piece type intraocular lens having a supporting portion. The diameter of the optical part of the evaluation lens was 6 mm, and the total length (maximum dimension) was 13 mm. Then, the evaluation lens was mounted on an injector, and the time required to open the evaluation lens when ejected in water at different environmental temperatures was measured.

As the injector, an injector having an inner diameter of the ejection port of 1.85 mm×1.75 mm (major axis×minor axis ellipse) that allows insertion of an intraocular lens through an incision of about 2.3 mm was used. As shown in Table 3 below, the test environment temperature was 21±1° C., 25±1° C., and 27±1° C., and each of the evaluation lens, injector, and water used in the experiment was the same. The test was conducted after acclimatizing for 2 hours or more in the measurement environment. The opening time was the time from when the entire evaluation lens was ejected from the injector to when the curled (folded) evaluation lens completely recovered (released) into a flat shape. The test was carried out with N=5, and the arithmetic mean value of the opening time is shown in Table 3 below.

As shown in Table 3, the intraocular lens of Example 1 had a short recovery time of 20 seconds or less at any environmental temperature. Such shape recovery in a short time is preferable in that the time required for insertion surgery is shortened. However, it was confirmed that the intraocular lens of Example 1 started to open while being ejected from the injector, and it was found that the intraocular lens was loaded by the tip of the nozzle of the injector. When inserting the intraocular lens through a smaller incision, it may be desirable for the intraocular lens to maintain its folded shape until the intraocular lens is completely ejected from the injector. From such a viewpoint, in the present technology, the recovery behavior in which the time from the injection of the intraocular lens to the complete recovery is about 30 seconds to 60 seconds is a preferable mode. On the other hand, the recovery time of the intraocular lens of Example 2 was in the range of 30 seconds to 60 seconds at any environmental temperature, and it was confirmed that the injection property was good. Regarding the recovery behavior, when there is a possibility that even a part of the intraocular lens remains in the nozzle of the injector and is constrained by the nozzle, the lens keeps its folded shape and the intraocular lens is It was confirmed that the lens opened promptly at the timing when it was completely ejected from (the timing when the restraint force from the injector was completely eliminated). From this, it was confirmed that the intraocular lens of Example 2 containing an appropriate amount of MMA had both flexibility suitable for injection property from the injector and appropriate rubber hardness and shape recovery property.

Although specific examples of the present technology have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

1 Intraocular lens 10 Optical part 20 Support part 20a Bending part 50 Injector 60 Cartridge

Claims (4)

Acrylic ester and methacrylic acid ester as a main component consisting of a copolymer of polymerizable monomer components,
The monomer component is
42 mass% or more and 62 mass% or less of phenoxyethyl acrylate,
35% by mass or more and 55% by mass or less of n-butyl methacrylate, and
3% by mass or more and 10% by mass or less of methyl methacrylate,
Intraocular lens, including The monomer component further has the following formula:
_{CH 2 = CH-COO-R} 1,
However, R ₁ in the formula is a linear, branched or cyclic functional group having 2 to 8 carbon atoms;
Containing a monomer component represented by 1 mass% or more and 10 mass% or less,
The soft intraocular lens according to claim 1. The soft intraocular lens according to claim 1 or 2, wherein the international rubber hardness is 30 or more and 40 or less. When molded to have a diameter of 6 mm and a frequency of 30D,
The soft intraocular lens according to any one of claims 1 to 3, wherein a load required to bend the diametrical direction so that the diametrical distance is 3 mm is 2 N or less.

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