JPH0947461A - Intraocular lens and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intraocular lens which has support parts rich in flexibility and/or resiliency and mechanical strength and an optically unstrained optical part and exhibits an excellent characteristic even in chemical resistance, solvent resistance or the like, and its advantageous manufacturing method. SOLUTION: A cross-linked copolymer composed of a mixture of 70.0 to 99.9wt% of one kind or two or more kinds of alkyl methacrylate with a cross- linking agent of 0.1 to 30.0wt.% is heated, and is pressurized in the first axis direction, and a lens material drawn in a radial shape in the direction vertical to the first axis direction is obtained. Such a lens material is worked, and an optical part 12 is formed so that the first axis direction and the optical axis direction coincide with each other, and a support parts 14 are integrally formed on the optical part 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intraocular lens in which an optical portion and a supporting portion are integrally formed from a single material and a method for manufacturing the same, and more particularly to flexibility and elasticity of the supporting portion and The present invention relates to an intraocular lens having improved mechanical strength and an advantageous manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, an intraocular lens which is implanted in the eye as a substitute for a crystalline lens removed for the treatment of cataract or the like has an optical section which is inserted into the eye and provides a desired visual acuity. It is composed of a support portion for holding the optical portion at a predetermined position in the eye.

As such an intraocular lens,
The optical part and the support part are formed of different materials,
In addition, a three-piece type or a two-piece type intraocular lens in which the supporting portion is fixed to the optical portion, and a one-piece type (integral type) configured by integrally forming the optical portion and the supporting portion from a single material Although two types of intraocular lenses are known, in recent years, one-piece type intraocular lenses have been widely used. Barefoot, the one-piece type intraocular lens, because of its configuration, there is no need to provide any mounting holes or the like for attaching the support part to the optical part, so compared to a three-piece type or two-piece type intraocular lens, This is because the manufacturing is simple and the effective area of the optical section can be secured sufficiently wide.

By the way, in these intraocular lenses, in general, the support portion is formed in the shape of an elongated rod, and the support portion is brought into contact with and supported by the eye tissue in the eye, whereby the optical portion is placed in the eye. Since it is fixed, the optical part is made of a material having high optical performance, and the supporting part is made of a material having excellent flexibility or elasticity and mechanical strength. However, in the one-piece type intraocular lens as described above, since the optical portion and the supporting portion are made of a single material, the optical portion is It was difficult to combine flexibility and elasticity, which are different from the required characteristics for the part, with mechanical strength, and for that reason, when it was implanted in the eye, it exhibited an elongated rod shape. Support unit that, in particular of the base portion will break off was greater risk of so-called breakage occurs.

Therefore, conventionally, a one-piece type intraocular lens has been proposed in which various measures are taken in order to solve the problem of breakage of the supporting portion.

[0006] For example, JP-A-3-503253, JP-A-6-218000, and JP-A-6-21800.
In Japanese Patent Laid-Open No. 1 etc., by devising various shapes of the base portion of the support portion, that is, the joint portion with the optical portion, the support portion can be made to have both flexibility and elasticity and mechanical strength. The disclosed intraocular lens is disclosed. However, in the intraocular lens disclosed in those publications,
In each case, since the shape of the supporting portion is carefully devised, the shape is naturally limited, and as a result, the free design of the intraocular lens is impaired. Existed.

Further, Japanese Patent Laid-Open No. 4-212349 discloses an intraocular lens formed by using a lens material formed by applying a special device. That is, in the intraocular lens disclosed in this publication, PMMA (polymethylmethacrylate) or its copolymer having excellent optical properties is stretched along at least two axes forming a predetermined angle with each other. The obtained sheet-shaped lens material is used, and the optical portion and the support portion are integrally formed by cutting and polishing the lens material. In such an intraocular lens, without any restrictions on its shape,
Free design is possible, and because the lens material is stretched in two or more polyaxial directions,
The polymerized chains are highly oriented, whereby excellent flexibility or elasticity and mechanical strength can be imparted to the supporting part, and the supporting part can be provided even when implanted in the eye. Therefore, it is possible to effectively prevent breakage, and further, due to the characteristics of the material that provides the lens material, excellent optical performance can be provided for the optical section. It has become.

However, in such an intraocular lens, the lens material is stretched only in a limited specific direction, though it is in two or more polyaxial directions, during the stretching treatment. Therefore, the alignment direction of the polymer chain is biased to such a specific direction, which inevitably causes optical distortion in the lens material, and such distortion is relative to the optical characteristics of the optical section. There was an extremely serious problem that it had an adverse effect and, as a result, the optical performance of the target intraocular lens was deteriorated.

Moreover, the inventors of the present invention prototyped an intraocular lens having the above-described structure, and when it was brought into contact with or immersed in a predetermined chemical or solvent, the intraocular lens was deformed, and in the extreme case, Has been confirmed to dissolve, and from this, the intraocular lens disclosed in the above publication has a shape stability upon contact with or immersion in a predetermined chemical or solvent, that is, chemical resistance. It has been revealed that the solvent resistance to the solvent is extremely poor.

[0010]

The present invention has been made in view of the above-mentioned circumstances, and the problem to be solved is to improve flexibility, elasticity and mechanical strength. It is an object of the present invention to provide an intraocular lens having a rich support portion and an optical portion having no optical distortion and exhibiting excellent characteristics in chemical resistance and solvent resistance. Moreover, in this invention, it is also a solution subject to provide the method of manufacturing the intraocular lens which has such an outstanding characteristic advantageously and easily.

[0011]

According to the present invention, in order to solve such a problem, an optical section which is inserted into the eye to provide a desired visual acuity and a predetermined optical section within the eye. A one-piece intraocular lens integrally formed from a supporting part which is held at a position, and a mixture of one or more kinds of alkyl methacrylate: 70.0-99.9% by weight and a cross-linking agent: 0 0.1 to 30.0 wt% of a cross-linked copolymer is heated and pressed in the first axial direction, and is radially stretched in a direction perpendicular to the first axial direction. Using such a lens material, the lens material is processed to form the optical portion so that the first axial direction and the optical axis direction substantially coincide with each other, and the supporting portion is integrated with the optical portion. The characteristic is that it is formed in a desired manner.

In the intraocular lens according to the present invention as described above, the lens material that provides the intraocular lens is a crosslinked copolymer composed of a mixture of one or more kinds of alkyl methacrylate in a specific ratio and a crosslinking agent. Since it is configured as
A three-dimensional crosslinked structure is formed in such a lens material (crosslinked copolymer), whereby the lens material swells, deforms, or is brought into contact with a predetermined chemical or solvent or is immersed, or Dissolution or the like can be effectively prevented.

Particularly, in such an intraocular lens, such a cross-linked copolymer is heated and pressurized in the first axial direction, whereby a radial direction is obtained in a direction perpendicular to the first axial direction. Since it is used as a lens material, the crosslinked copolymer should be stretched substantially uniformly in all directions perpendicular to the first axial direction. The lens material can be constituted so that the polymer chains of the cross-linked copolymer can be highly oriented, and as a result, the flexibility and elasticity as well as the mechanical strength of the lens material are significantly improved. Moreover, it is possible to prevent the orientation of the polymer chains from being biased in a specific direction, and it is possible to effectively prevent the occurrence of optical distortion in the lens material.

In such an intraocular lens, such a lens material is processed to form an optical portion such that the first axial direction and the optical axis direction substantially coincide with each other, and Since the support portion is integrally formed with the optical portion, it is possible to effectively prevent the occurrence of distortion that adversely affects the optical characteristics of the optical portion. In addition, the elasticity and the mechanical strength can be advantageously improved.

Therefore, the intraocular lens according to the present invention can be constituted by having a support portion having a high flexibility or elasticity and a mechanical strength and an optical portion having no optical distortion, The problem of breakage of the support part during implantation in the eye can be very advantageously solved without impairing the optical characteristics of the optic part, and as a result, even after the implantation in the eye, the eye has excellent optical performance. It can be stably retained inside, and can also exhibit excellent properties in chemical resistance, solvent resistance, etc., and its shape can be stably maintained in the eye, resulting As
The safety for the inserted person can be effectively ensured.

According to the preferred first aspect of the intraocular lens according to the present invention, methyl methacrylate is used as the alkyl methacrylate, whereby the magnitude of the optical distortion in the optical part is increased. The value of the photoelastic constant represented can be made smaller, and as a result, further excellent optical performance can be obtained in the optical section.

According to a second preferred aspect of the present invention, ethylene glycol dimethacrylate is used as the cross-linking agent, and thus, especially when methacrylate is used as the alkyl methacrylate. The copolymerizability with methacrylate can be advantageously improved to give a copolymer with a better degree of cross-linking, so that the chemical and solvent resistance of the intraocular lens formed from the lens material. The sex can be enhanced more effectively.

Furthermore, according to an advantageous third aspect of the present invention, the crosslinked copolymer comprises 90.0 to 99.0% by weight of the alkyl methacrylate and 1.0 to 1% of the crosslinking agent.
0.0% by weight, whereby the lens material can be constructed with a better degree of cross-linking, and the chemical resistance and solvent resistance of the intraocular lens formed from the lens material are more effective. In addition, appropriate hardness can be imparted to the support portion of the intraocular lens, and breakage of the support portion during implantation in the eye can be more effectively prevented. It will be.

Furthermore, according to a fourth preferred aspect of the present invention, the cross-linked copolymer is stretched at a stretch ratio within a range of 5 to 70% to form the lens material, whereby. The stretching ratio, which is the ratio of the increase in the size of the cross-linked copolymer after stretching to the size of the cross-linked copolymer before stretching, can be set to an appropriate value, and the deterioration of the optical performance due to excessive stretching can be prevented. The polymer chains of the cross-linked copolymer can be oriented to a higher degree without causing the possibility of inducing, and as a result, the support part has more excellent flexibility or elasticity and mechanical strength. To get.

In the present invention, the optical part which is inserted into the eye to provide a desired visual acuity and the supporting part which holds the optical part at a predetermined position in the eye are integrally formed. In a method of manufacturing an integrated intraocular lens comprising
(A) One or a mixture of two or more alkyl methacrylates: 70.0 to 99.9% by weight and a crosslinking agent: 0.1 to 3
A step of preparing a cross-linked copolymer comprising 0.0% by weight, and (b) pressurizing the cross-linked copolymer in the first axial direction in a heated state to obtain the first axial direction. A step of forming a lens material by radially extending it in a direction perpendicular to, and (c) processing the lens material so that the first axial direction and the optical axis direction substantially coincide with each other. The step of forming the optical part and integrally forming the support part with respect to the optical part is also a feature thereof.

In the method for producing an intraocular lens according to the present invention, one or two alkyl methacrylates are used.
In a state where the cross-linked copolymer consisting of a mixture of one or more kinds and a cross-linking agent is heated, by pressing in the first axial direction, it is radially stretched in a direction perpendicular to the first axial direction, Since the lens material is formed, the lens material is formed by stretching the uncrosslinked predetermined material in a multiaxial direction by pulling in a plurality of directions. Unlike the conventional method described above, the stretching process can be performed extremely advantageously and easily.

Therefore, according to the method of the present invention, an intraocular lens made of such a lens material and having the above-mentioned excellent characteristics can be manufactured extremely advantageously and easily as compared with the conventional method. That will be the case.

According to the first preferred embodiment of the method for producing an intraocular lens according to the present invention, the methyl methacrylate is used as the alkyl methacrylate to form the lens material, and thereby, the lens material is formed. The cutting and polishing of the lens material can be performed more easily, and as a result, the intraocular lens can be manufactured with further excellent productivity.

According to the second preferred embodiment of the method of the present invention, ethylene glycol dimethacrylate is used as the cross-linking agent, which constitutes the cross-linking copolymer when it is prepared. The cross-linking agent can be easily purified, so that the cross-linked copolymer and thus the intraocular lens can be produced more efficiently.

Furthermore, according to an advantageous third aspect of the method of the present invention, the cross-linked copolymer comprises 90.0-99.0% by weight of the alkyl methacrylate and 1.0% of the cross-linking agent.
It is composed of 0.1% by weight to 10.0% by weight, whereby an intraocular lens having superior chemical resistance and solvent resistance and capable of more effectively preventing breakage of the support portion is advantageously used. You can get it.

Further, according to the fourth preferred embodiment of the method of the present invention, the crosslinked copolymer is stretched at a stretching ratio within the range of 5 to 70% to form the lens material. Therefore, it is possible to effectively impart more excellent flexibility or elasticity and mechanical strength to the supporting portion.

[0027]

1 and 2, there is schematically shown an example of an intraocular lens having a structure according to the present invention. There, the intraocular lens 10 is integrally configured from the optical portion 12 and the two support portions 14 and 14.

More specifically, the optical section 12 has a circular shape in a front view, and both the front surface (left side surface in FIG. 2) and the rear surface (right side surface in FIG. 2) are convex in a side view. It has a biconvex lens shape. On the other hand, the support portion 14,
Reference numeral 14 denotes a slender rod shape, which is integrally formed with the optical portion 12, and protrudes from the two peripheral portions of the optical portion 12 facing each other by 180 ° in predetermined directions in opposite directions. Further, the optical portion 12 is formed so as to be curved and extended in the circumferential direction, and the tip portion thereof is a free end without connection.

Thus, in the intraocular lens 10 as described above, the disc-shaped optical portion 12 and the two loop-shaped supporting portions 1 are provided.
4 and 14 are integrally formed to have an integrated structure, and in the same manner as in the conventional case,
When inserted into the eye, the support portions 14, 14 contact the eye tissue,
By being supported, the optical unit 12 is fixed to the crystalline lens site in the eye, and the optical unit 12 can provide a desired visual acuity.

By the way, such an integral type intraocular lens 10 is constructed by using a lens material composed of a cross-linked copolymer of a cross-linking agent and a mixture of one or more kinds of alkyl methacrylate. . That is, the lens material that provides the intraocular lens 10 is obtained by cross-linking and copolymerizing one or a mixture of two or more alkyl methacrylates, which are known to have high optical properties, and a cross-linking agent, and three-dimensionally being inside thereof. A bridging structure is formed and configured, whereby excellent optical performance is imparted to such a lens material, and the lens material is brought into contact with a predetermined chemical or solvent, Even when immersed, it is possible to effectively prevent swelling, deformation, and dissolution.

As the alkyl methacrylate constituting the cross-linked copolymer which gives such a lens material,
The structure is not particularly limited, and those usable in the eye, for example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, hexafluoropropyl methacrylate, benzyl methacrylate, trimethacrylate. Any of fluoroethyl methacrylate, tetrafluoropropyl methacrylate and the like can be used. Of these, one kind is used alone, or two or more kinds are mixed and used, but methyl methacrylate is preferably selected and used. Kashidashi, by using this methyl methacrylate,
Cutting and polishing of the lens material can be performed relatively easily, and the intraocular lens 10 formed of the lens material is also available.
This is because the value of the photoelastic constant representing the magnitude of the optical distortion in the optical section 12 can be advantageously reduced.

As the cross-linking agent, a known polyfunctional monomer (having two or more ethylenic unsaturated bonds) copolymerizable with the alkyl methacrylate as described above, for example,
There are ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, allyl methacrylate, 4-vinylbenzyl methacrylate, 3-vinylbenzyl methacrylate, etc., and if necessary, one or two of them may be used. More than one species are selected and used. Among them, ethylene glycol dimethacrylate is particularly preferably used. Because this ethylene glycol dimethacrylate is easy to purify, it can be obtained in good yield, and thereby a cross-linked copolymer can be efficiently obtained with the alkyl methacrylate. Is. Further, since such ethylene glycol dimethacrylate is particularly excellent in copolymerizability with methyl methacrylate, it is more preferably used when methyl methacrylate is selected as the alkyl methacrylate.

In a cross-linked copolymer composed of a mixture of one or two of these alkyl methacrylates and a cross-linking agent, if the cross-linking agent is used in an unnecessarily large amount,
The resulting cross-linked copolymer is excessively cross-linked, and the hardness of the lens material becomes too high, which causes a problem that it becomes brittle. Conversely, when the content of the cross-linking agent is too small, the degree of cross-linking is remarkable. As a result, the size of the lens becomes smaller, and thus the intraocular lens 10 has a problem that it is obtained by the cross-linking of a polymer of alkyl methacrylate and that the above-described effects cannot be effectively enjoyed. Therefore, in order to avoid these problems, in such a cross-linked copolymer, one or a mixture of two or more kinds of alkyl methacrylate is 70.0-9.
In an amount of 9.9% by weight, the crosslinking agent is 0.1
It is necessary to be copolymerized in an amount of about 30.0% by weight. Further, in order to obtain a more appropriate degree of crosslinking and hardness, 1
It is desirable that 90.0 to 99.0% by weight of one kind or a mixture of two or more kinds and 1.0 to 10.0% by weight of a crosslinking agent are copolymerized.

By the way, such a cross-linked copolymer is the same as a conventional one with respect to a monomer blend obtained by blending a mixture of one or more kinds of alkyl methacrylate and a cross-linking agent in the above-mentioned proportions. It is obtained by performing various polymerization operations. That is, for example, after the radical polymerization initiator is added to such a monomer mixture, the mixture is gradually heated from room temperature to about 130 ° C. over a predetermined time to complete the polymerization (heat polymerization), Alternatively, after the photopolymerization initiator is added to the monomer mixture, the light ray having a wavelength corresponding to the absorption band of the photopolymerization initiator (for example, ultraviolet ray) is irradiated to perform polymerization (photopolymerization). , The monomer blend was cross-linked, copolymerized and constructed.

When the crosslinked copolymer is thus obtained,
When heat polymerization is performed on the monomer mixture, the heating operation may be performed in a constant temperature bath or a constant temperature chamber, or may be performed by irradiating an electromagnetic wave such as a microwave. The heating may be performed in stages. On the other hand, when photopolymerization is performed, a sensitizer may be further added. In addition, whether the heat polymerization or the photopolymerization is carried out, the polymerization initiator (radical polymerization initiator or photopolymerization initiator) used therefor is the same as the conventional one. It will be used in various mixing ratios. Further, in order to efficiently produce the lens material, it is preferable to adopt a method by bulk polymerization as a polymerization method, but it is also possible to adopt a method by solution polymerization instead.

If desired, the cross-linked copolymer thus obtained may contain an ultraviolet absorber, a coloring agent, etc. The UV absorber and the colorant may be any of those conventionally used for intraocular lenses, but from the viewpoint of chemical resistance and elution resistance, the UV absorber may be an acryloyl group, Polymerizable UV absorbers such as benzophenone-based, benzotriazole-based, salicylic acid derivative-based, etc. having a methacryloyl group, a vinyl group, an allyl group, and a polymerizable group such as isopropenyl group, and as a colorant, the above-mentioned polymerizable Azo-based, anthraquinone-based, nitro-based, and phthalocyanine-based polymerizable colorants having a group are preferably used, respectively, and among these polymerizable ultraviolet absorbers and polymerizable colorants, the mole at 480 nm is preferable. Extinction coefficient is about 2 ×
Those having 10 ² or more are particularly preferably used. Thus, such an ultraviolet absorber or a colorant may be simply blended with the cross-linked copolymer in the same blending ratio as the conventional one, or may be chemically bound by polymerization. Thus, the retina in the eye into which the intraocular lens 10 is inserted can be effectively protected from ultraviolet rays, and the change in color vision with respect to a normal eye can be suppressed as much as possible.

Then, as described above, the cross-linked copolymer thus obtained constitutes a lens material, and this lens material is further processed to form the intraocular lens 1.
However, in general, first, as shown in FIG. 3, a cross-linked copolymer 15 obtained by the above-mentioned polymerization operation is formed at the same time as the formation thereof.
Alternatively, after being formed, it is configured to have a substantially thick disk shape.

That is, when the crosslinked copolymer 15 is formed, the monomer blend is filled in a cylindrical mold or a container, and the polymerization operation as described above is performed, whereby the mold or the container is formed. Depending on the shape of, it is molded with a substantially thick disk shape, or after being molded into a predetermined shape, by cutting etc.,
Similarly, it has a substantially thick disk shape. Further, by adopting these two molding methods, first, a columnar cross-linked copolymer having a predetermined height is molded, and then this is cut into a predetermined thickness to have a desired thickness. A plurality of disc-shaped cross-linked copolymers 15 may be formed at once.

Next, such a disc-shaped cross-linked copolymer 15 is heated to a predetermined temperature in the first axial direction, here, in its thickness direction (arrow direction in FIG. 3). By pressurizing, the lens material 16 having a flat thin disk shape, as shown in FIG. 4, which is radially stretched in the direction perpendicular to the thickness direction is formed. Thus, in such lens material 16,
By being radially stretched in the direction perpendicular to the thickness direction, the polymer chain can be highly oriented without being biased in a specific direction, and as a result, its flexibility or elasticity can be obtained. In addition, the mechanical strength can be very advantageously and easily improved, and the occurrence of optical distortion can be effectively prevented.

The heat treatment temperature of the cross-linked copolymer 15 at the time of forming the lens material 16 depends on the cross-linked copolymer 1
It is appropriately determined according to the characteristics of 5 and is not particularly limited, but is generally in the range from the glass transition temperature of the cross-linked copolymer 15 to a temperature 30 ° C. higher than it. That is, for example, it is composed of 97.0% by weight of methyl methacrylate and 3.0% by weight of ethylene glycol dimethacrylate and has a glass transition temperature of about 120.
120 to 150 for the cross-linked copolymer 15 having a temperature of
It is heat-treated within the temperature range of ° C. When the heat treatment temperature of such a cross-linked copolymer 15 is lower than the glass transition temperature of the cross-linked copolymer 15, the cross-linked copolymer 15 is sufficiently contained in the stretching treatment performed after the heat treatment. If it is higher than the glass transition temperature plus 30 ° C., then the crosslinked copolymer 1
The three-dimensional bridge structure in 5 is destroyed, and the effect obtained by forming such a three-dimensional bridge structure in the lens material 16 and thus in the intraocular lens 10 cannot be sufficiently exerted. Or, in the cross-linked copolymer 15, monomerization occurs and air bubbles enter, and as a result, the optical performance is significantly deteriorated.

The magnitude of the pressurizing pressure at the time of pressurizing the crosslinked copolymer 15 formed by such heat treatment is determined by the kind of the crosslinked copolymer 15, that is, the crosslinked copolymer 15. Although it is appropriately determined depending on the type of the alkyl methacrylate and the cross-linking agent constituting the composition, it is generally 1 to 10000 kg / cm ² . By pressurizing in the thickness direction of the first axial direction crosslinked copolymer 15 within such a pressure range, the crosslinked copolymer 15 is pressed.
However, it can be radially and sufficiently stretched in a direction perpendicular to the thickness direction without being broken or damaged.

Then, the lens material 16 thus obtained is subjected to a cutting process, and as shown in FIG. 5, the lens material 16 is the target intraocular lens 1
It is configured as a lens cutting disk plate 17 having a size slightly larger than zero. Further, subsequently, the lens cutting disk plate 17 is mechanically processed by using a cutting tool such as an end mill, so that the optical portion 12 has a disk shape as shown by an imaginary line in FIG. And in its thickness direction, ie lens material 16
Of the two supporting portions 14, 1 so that the direction of pressurizing the cross-linked copolymer 15 and the direction of the optical axis at the time of formation of the
4 is cut out from the lens material 16 in a state of being integrally connected to the optical portion 12 having a loop shape. Then, both side surfaces of the optical portion 12 in the thickness direction are polished so that each of them has a predetermined convex shape and the supporting portions 14 and 14 have an elongated rod shape. Thus, the optical unit 12 and the supporting unit 1
4, 14 and 14 are integrally formed from a single material, so that FIG.
The intraocular lens 10 as shown in FIG. 1 is constructed to have an integral structure.

As described above, since the intraocular lens 10 is formed by using the lens material 16 which is excellent in flexibility, elasticity and mechanical strength and has no optical distortion, it is flexible. It can be configured to have the supporting portions 14 and 14 having high elasticity or elasticity and mechanical strength, and the optical portion 12 having no optical distortion, so that the optical characteristics of the optical portion 12 are not impaired. The problem of breakage of the supporting portions 14 and 14 during implantation into the inside can be advantageously solved, and the stretching process for forming the lens material 16 can be performed more advantageously and easily than in the past. As a result, the excellent features described above can be realized very easily and advantageously.

Here, when the crosslinked copolymer 15 having a substantially thick disk shape is pressed to form the flat thin disk lens material 16, for example, a pressure as shown in FIG. 6 is applied. The device is used. That is, the pressurizing device 18 shown in FIG. 6 moves relatively close to and away from the fixed die 19 fixed to a predetermined base (not shown) and the fixed die 19 by a hydraulic mechanism or the like. And a movable mold 20 configured to obtain. The lens material placement plate 22 is fixedly installed on the surface of the fixed die 19 facing the movable die 20. Also,
The lens material arranging plate 22 is made of a hard material such as metal or Teflon resin and has a substantially thin rectangular flat plate shape, and the central portion thereof has a substantially thick disk shape formed as described above. The lens material arranging hole 24 having a diameter larger than the cross-linked copolymer 15 by a predetermined dimension and a depth shallower than the thickness is formed in which the cross-linked copolymer 15 is arranged.

Then, by using such a pressurizing device 18, the cross-linked copolymer 15 is disposed in the lens material disposing hole 24 of the lens material disposing plate 22 installed in the fixed die 19 of the pressurizing device 18. In the squeezed state, the pressurizing device 18 and the cross-linked copolymer 15 are provided by a predetermined heater means (not shown) or the like.
By moving the movable die 20 closer to the fixed die 19 while heating, the cross-linked copolymer 15 is pressurized in the direction in which the movable die 20 and the fixed die 19 face each other, and the cross-linked copolymer 15 is perpendicular to the facing direction. A lens material 16 as shown in FIG. 4 which is radially extended in a direction and is sized to correspond to the lens material placement holes 24 of the lens material placement plate 22.
Is formed.

By the way, in this example, each of the support portions 14
However, one was extended from each of the two locations of the optical portion 12 that are opposite to each other by 180 ° in the peripheral edge portion, but the arrangement form and the number of such support portions 14 are by no means limited to this. Absent.

Further, the shape of the support portion 14 is not limited to the one in this example, and various known shapes can be adopted.

Further, in the present embodiment, the tip of the support portion 14 is a free end without connection, but it is also possible to integrally connect the tip to the peripheral edge of the optical portion 12. Of course it is possible.

Furthermore, in this embodiment, no reference is made to the optical characteristics of the optical section 12, but in the present invention, any optical section having any optical characteristics can be advantageously employed. For example, one having a monofocal optical characteristic (monofocal), one having a plurality of focal areas such as two focal points [bi (multi) focal], or the dioptric power in the circumferential direction continuously changes. Any toric surface or the like can be suitably adopted, and the surface shape of the optical section 12 is not limited to the one shown in the present specific example, and a planar shape or A concave shape or other various shapes can be adopted.

Further, in this example, the pressurizing device 18 as shown in FIG. 6 was used to pressurize the crosslinked copolymer to form the lens material. A pressure device having any structure can be used as long as it can be radially compressed in a direction perpendicular to the uniaxial direction by pressing in a direction, and even if such a pressure device is not used, crosslinking can be performed. If the stretching treatment can be performed on the copolymer, it is not always necessary to use a pressure device.

In this example, one lens material 1 is used.
Although one intraocular lens 10 is formed from 6 pieces, a plurality of intraocular lenses 10 can be obtained from one lens material 16 by variously changing the size of the lens material. It is also possible to

[0052]

EXAMPLES Some examples of the present invention will be shown below to clarify the present invention in more detail. However, the present invention is not limited by the description of such examples. Needless to say, it is not something to receive. In addition, the present invention, in addition to the following examples, in addition to the above specific description, various modifications based on the knowledge of those skilled in the art, unless departing from the spirit of the present invention,
It should be understood that modifications, improvements and the like can be made.

Example 1 First, 97% by weight of methyl methacrylate as an alkyl methacrylate and 3% by weight of ethylene glycol dimethacrylate as a crosslinking agent were mixed, and 0.005% by weight was added to the monomer mixture. 2,2-azobis (2,4-dimethylvaleronitrile), which is a polymerization initiator, was added and mixed at a ratio of 2 to obtain a mixture. Then, the obtained mixture was placed in a cylindrical plastic container having an inner diameter of 35 mm, and the container was tightly closed at 35 ° C.
5 days → 40 ° C for half a day → 45 ° C for half a day → 50-70 ° C
By gradually heating for 4 hours → 100 to 110 ° C. for 12 hours, methyl methacrylate and ethylene glycol dimethacrylate were copolymerized and crosslinked to obtain a crosslinked copolymer.

Then, the cross-linked copolymer thus obtained was taken out from the plastic container and cut into a disk shape having a diameter of 30 mm and a thickness of 6 mm. And
After that, the cut cross-linked copolymer is placed in the lens material placement hole 24 of the lens material placement plate 22 attached to the fixed die 19 of the pressure device 18 as shown in FIG. Movable type 20 while heating with
Was moved closer to the fixed mold 19, and the cross-linked copolymer was pressurized at a pressure of 20 kgf / cm ² . As a result, the movable mold 20 and the fixed mold 19 are radially extended in the direction opposite to each other, that is, the direction perpendicular to the thickness direction of the cross-linked copolymer, and the diameter corresponding to the size of the lens material placement hole 24 is 45 mm. ,
A lens material having a thickness of 3 mm was obtained.

Thereafter, the lens material is cut into a disc plate shape having a diameter of 15.5 mm and a thickness of 3 mm, and the disc plate-shaped lens material is attached to a known cutting machine for cutting. By processing, the optical part was formed so that the thickness direction of the lens material and the optical axis direction were substantially coincident with each other, and the support part was integrally formed with the optical part. Then, after that, the optical portion and the supporting portion were subjected to polishing processing to obtain the desired intraocular lens 10 as shown in FIG. Here, the diameter of the optical part of the intraocular lens 10 was 6.3 mm, and the total length (the length indicated by m in FIG. 1) was 12.5 mm.

Using the thus obtained intraocular lens 10, the total length of the intraocular lens is 1.0 mm, 2.
The compressive load test for measuring the force required for compressing 0 mm and 3.0 mm, that is, the so-called compressive load is performed as follows, and thereby the flexibility or elasticity of the support portion 14 of the intraocular lens 10 is examined. It was That is, first, the intraocular lens 10 was vertically fixed on a balance, and then the entire length thereof was measured with a micrometer to adjust the degree of compression. Next, the scale of the balance was adjusted to 0 so that the degree of compression was the same as the entire length of the intraocular lens 10 measured. And about 1 in 5 seconds
Rotate the micrometer at a constant speed so that
Every time the intraocular lens 10 was compressed by 1 mm, the scale of the balance was read and the compression load of each was measured.

As a result, when the entire length of the intraocular lens 10 was compressed by 1 mm, a compression load of about 100 mg was exhibited. Also,
A compression load of about 250 mg when compressed by 2 mm and a compression load of about 450 mg when compressed by 3 mm were shown. From this,
It was confirmed that the support portion 14 of the intraocular lens 10 was excellent in flexibility and elasticity.

Then, for comparison, the intraocular lens 10 is made of the same material as the intraocular lens 10, but the same structure as the conventional one in which the lens material is not stretched at all. And an intraocular lens having the above-mentioned two types were immersed in a solvent such as water. Then, in that state, the supporting portions of the two intraocular lenses are flexibly deformed so as to be bent in the entire length direction of each intraocular lens (the arrow direction in FIG. 7) as shown in FIG. The amount of deformation (the dimension indicated by n in FIG. 7) in the lengthwise direction at the time of breaking (breaking) was measured. As a result, in the intraocular lens having the conventional structure, the support portion ruptures when it is flexibly deformed by 6 mm in the entire length direction of the intraocular lens, but in the intraocular lens 10, the support portion 14 is broken. Is 9 in the length direction of the intraocular lens 10.
Even when it was flexed and deformed, it did not break.

Even if the supporting section 14 is bent in the circumferential direction of the optical section 12 (the arrow direction in FIG. 8) using the intraocular lens 10 as shown in FIG. It never broke.

From these facts, the intraocular lens 10
However, it was recognized that the mechanical strength of the support portion 14 in a solvent such as water was superior to that of the conventional structure.

Furthermore, the presence or absence of optical distortion of the optical section 12 of the intraocular lens 10 having the above-described structure was examined by a strain gauge known in the related art. Nothing was confirmed. From this, it was confirmed that the optical section 12 of the intraocular lens 10 has excellent optical characteristics.

Example 2 First, 97% by weight of methyl methacrylate as an alkyl methacrylate and 3% by weight of ethylene glycol dimethacrylate as a cross-linking agent were mixed, and the monomer mixture was used as a polymerization initiator. 2,2-Azobis (2,4-dimethylvaleronitrile): 0.01% by weight, and 1-phenylazo-3-methacryloyloxy-2-naphthalenol as a colorant: 0.0016% by weight
Was added and mixed to obtain a mixture. Then, the obtained mixture was subjected to the same polymerization operation as in Example 1 to obtain a cross-linked copolymer containing a colorant, and further from the cross-linked copolymer in Example 1 above. An intraocular lens 10 as shown in FIG. 1 was obtained, which differs from the molded intraocular lens only in that it contains a colorant.

A compression load test was conducted using such an intraocular lens 10 in the same manner as in Example 1, and when the total length of the intraocular lens 10 was compressed by 1 mm, it was about 120 mg. , About 300mg when compressed by 2mm,
When compressed by 3 mm, a compression load of about 500 mg was exhibited.

Further, in the same manner as in the first embodiment, with the intraocular lens 10 immersed in a solvent such as water, as shown in FIG. 7, the support portion 14 is provided in the entire length direction of the intraocular lens 10. When flexurally deformed, the supporting portion 14 was not broken even when the amount of deformation became 9 mm. On the other hand, although it is made of the same material as the intraocular lens 10, the lens material is not stretched at all.
When an intraocular lens having the same structure as the conventional one was subjected to the same test, the supporting portion broke when the amount of deformation reached 6.5 mm.

Further, as shown in FIG.
The supporting portion 14 was not broken even when the optical element 12 was bent in the circumferential direction (the arrow direction in FIG. 5).

Furthermore, when the presence or absence of optical distortion of the optical part 12 of the intraocular lens 10 was examined by a conventionally known strain gauge, no distortion which was a problem in use was confirmed. .

From these facts, in the intraocular lens 10 having the above-mentioned structure, even if the colorant is contained, the support portion 14 has a high degree of flexibility or elasticity and mechanical strength. Can be combined with the optical section 12
In, it can be recognized very clearly that excellent optical performance can be exhibited.

[0068]

As is apparent from the above description, in the intraocular lens according to the present invention, the support portion having high flexibility or elasticity and mechanical strength, and the optical portion having no optical distortion are provided. Can be configured to have, thereby, can be stably retained in the eye with excellent optical performance, moreover, excellent properties can be exhibited in chemical resistance, solvent resistance, etc., The shape can be stably maintained in the eye, and as a result, safety for the inserted person can be effectively ensured.

Further, according to the method for producing an intraocular lens according to the present invention, the stretching treatment for the crosslinked copolymer which gives the lens material can be performed more advantageously and easily as compared with the conventional method, whereby Therefore, the intraocular lens having the excellent characteristics as described above can be manufactured extremely advantageously and easily from the lens material.

[Brief description of drawings]

FIG. 1 is a front explanatory view showing an example of an intraocular lens according to the present invention.

FIG. 2 is a right side view of the intraocular lens shown in FIG.

FIG. 3 is an explanatory diagram showing an example of one step of the method of the present invention.

FIG. 4 is an explanatory diagram showing another example of steps of the method of the present invention.

FIG. 5 is an explanatory diagram showing still another example of steps of the method of the present invention.

FIG. 6 is an explanatory view showing an example of a pressurizing device adopted when performing one step of the method of the present invention shown in FIG.

FIG. 7 is an explanatory view showing a state in which the support portion is bent in the entire length direction of the intraocular lens in order to check the mechanical strength of the support portion in the intraocular lens shown in FIG.

FIG. 8 is an explanatory diagram showing a state in which the support section is bent in the circumferential direction of the optical section in order to check the mechanical strength of the support section in the intraocular lens shown in FIG.

[Explanation of symbols]

10 Intraocular lens 12 Optical part 14 Support part 15 Crosslinking copolymer 16 Lens material 17 Disc plate for lens cutting 18 Pressurizing device 19 Fixed type 20 Movable type 22 Lens material arrangement plate 24 Lens material arrangement hole

Claims (10)

[Claims] 1. An integrated intraocular body comprising an optical unit that is inserted into the eye to provide a desired visual acuity and a support unit that holds the optical unit at a predetermined position in the eye. In the lens, one or a mixture of two or more alkyl methacrylates:
70.0-99.9% by weight and cross-linking agent: 0.1-30.0
By using a lens material obtained by heating a cross-linked copolymer consisting of 1 wt% and pressurizing in the first axial direction and radially stretched in a direction perpendicular to the first axial direction, By processing such a lens material to form the optical portion so that the first axial direction and the optical axis direction substantially coincide with each other, the supporting portion is integrally formed with the optical portion. A featured intraocular lens. 2. The intraocular lens according to claim 1, wherein the alkyl methacrylate is methyl methacrylate. 3. The intraocular lens according to claim 1, wherein the cross-linking agent is ethylene glycol dimethacrylate. 4. The crosslinked copolymer is composed of 90.0 to 99.0% by weight of the alkyl methacrylate and 1.0 to 10.0% by weight of the crosslinking agent.
Alternatively, the intraocular lens according to claim 3. 5. The eye according to any one of claims 1 to 4, wherein the lens material is formed by stretching the crosslinked copolymer at a stretching ratio within a range of 5 to 70%. Inner lens. 6. An integrated intraocular body comprising an optical part that is inserted into the eye to provide a desired visual acuity and a support part that holds the optical part at a predetermined position in the eye. A method of making a lens, comprising one or more mixtures of alkyl methacrylates:
70.0-99.9% by weight and cross-linking agent: 0.1-30.0
A step of preparing a cross-linked copolymer consisting of 1 wt% and a direction perpendicular to the first axial direction by pressurizing the cross-linked copolymer in the first axial direction in a heated state. A step of forming a lens material by drawing the lens material radially, and forming the optical part such that the lens material is processed so that the first axial direction and the optical axis direction substantially coincide with each other. A step of integrally forming the support part with the optical part, the manufacturing method of the intraocular lens. 7. The method for manufacturing an intraocular lens according to claim 6, wherein the alkyl methacrylate is methyl methacrylate. 8. The method for producing an intraocular lens according to claim 6, wherein the crosslinking agent is ethylene glycol dimethacrylate. 9. The crosslinked copolymer comprises 90.0 to 99.0% by weight of the alkyl methacrylate and 1.0 to 10.0% by weight of the crosslinking agent.
Alternatively, the method for manufacturing the intraocular lens according to claim 8. 10. The eye according to claim 6, wherein the cross-linked copolymer is stretched at a stretching ratio within a range of 5 to 70% to form the lens material. Inner lens manufacturing method.