JPH0614942B2 - Method for producing harmful ultraviolet ray-cut artificial lens - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an artificial lens to be transplanted into the eyeball after cataract surgery, and more specifically, to produce an artificial lens having a function of cutting harmful ultraviolet rays. Regarding the method. The harmful ultraviolet ray-cut artificial lens obtained by the production method of the present invention is used for visual acuity correction after cataract surgery.

<Prior Art> For cataracts in which the crystalline lens of the eyeball becomes cloudy, in recent years, the crystalline lens has been surgically removed and then an artificial crystalline lens is transplanted.
BACKGROUND OF THE INVENTION It has become widespread to perform vision correction.

The artificial lens supports the lens that corrects vision and supports it.
It consists of a support for fixing the lens in place in the eye. The lens part is usually polymethylmethacrylate (hereinafter abbreviated as PMMA) or crosslinked PMMA.
Is made of. Since PMMA is optically transparent, has good biocompatibility, and excellent mechanical strength, it is currently the most suitable material as an artificial lens material. However, when compared with the crystalline lens of a living body, the ultraviolet absorption characteristics, hardness, refractive index, etc. are different. In particular, the ultraviolet absorption characteristics are not performed, and ultraviolet rays reach the retina and cause damage. For this reason, conventionally, a PMMA artificial crystalline lens in which a UV absorber is mixed with PMMA to block UV rays has been proposed. Also,
A method has also been proposed in which a polymerizable group is introduced into an ultraviolet absorber and copolymerized with methyl methacrylate to bond the ultraviolet absorber to the molecular chain by simple mixing. However, in any case, the ultraviolet absorber is uniformly distributed throughout the artificial lens. As the ultraviolet absorber, salicylic acid-based, benzophenone-based, benzotriazole-based, cyanoacrylate-based, etc. are used, but all of them are highly toxic, and if they are dissolved in the eye, they may develop into serious eye disorders. In normal intraocular transplantation, if PMMA is completely polymerized, the elution is expected to be extremely small, but when performing surgery with YAG laser or the like for the treatment of post-cataracts that occur after cataract surgery. Since the laser beam is radiated through the artificial lens, the surface of the artificial lens itself may be damaged. At this time, there is a very high possibility that the toxic ultraviolet absorber will be eluted from the destroyed portion of the surface of the artificial lens. It is unavoidable that adverse effects will occur due to the elution of harmful UV absorbers in the closed eyeball.

<Problems to be Solved by the Invention> As described above, since the conventional artificial lens does not contain any ultraviolet absorber, ultraviolet rays reach the retina and cause a disorder, or the one containing an ultraviolet absorber is used. However, when it is irradiated with a YAG laser or the like, it has a drawback that harmful ultraviolet absorbers are eluted due to surface damage of the artificial lens.

In view of the above-mentioned drawbacks, the present inventors have developed an artificial crystalline lens that does not elute the ultraviolet absorbent even when irradiated with YAG laser or the like in the treatment of subsequent cataracts, and blocks harmful ultraviolet rays, and has higher safety. As a result of intensive studies, the present invention has been completed.

That is, the first object of the present invention is to provide a method for producing an artificial crystalline lens in which harmful ultraviolet rays are prevented from being transmitted. A second object of the present invention is to provide a method for manufacturing an artificial crystalline lens having a light transmission characteristic which is similar to that of a normal crystalline lens. A third object of the present invention is to provide a highly safe method for producing an artificial crystalline lens in which harmful ultraviolet absorbers do not elute even if the surface of the artificial crystalline lens is damaged by a YAG laser or the like.

Other objects and advantages of the invention will be apparent from the description below.

<Means for Solving Problems> The present invention has been made to achieve the above object, and a method for producing a harmful ultraviolet ray-cutting artificial crystalline lens of the present invention is to provide an ultraviolet ray on an optically transparent polymethylmethacrylate. It is characterized in that a cut filter is arranged, the ultraviolet cut filter is covered with an optically transparent methyl methacrylate monomer, and the ultraviolet cut filter is sealed by polymerizing the methyl methacrylate monomer.

The artificial lens targeted by the present invention is mainly composed of PMMA, and in this case, it may be cross-linked PMMA.

The UV cut filter may be any one that cuts UV light having a wavelength of about 400 nm or less, and a plastic filter, a glass filter or the like can be used. Since this filter is embedded in the artificial lens, the refractive index of the material of the filter is preferably the same as the refractive index of the material of the artificial lens. As such a filter, an ultraviolet cut plastic filter made of PMMA or cross-linked PMMA, or a known glass filter having an ultraviolet absorbing ability per se is preferable.

To make a PMMA UV cut filter,
An ultraviolet absorber is added to the MA monomer, and the mixture is uniformly mixed and dissolved, and then polymerized and molded into a plate shape, a rod shape, a button shape or the like.
Then, it is finished into a desired shape such as a flat plate or a lens shape by machining, polishing or the like. It is also possible to directly cast and polymerize the filter using a molding die.

Examples of the ultraviolet absorber include salicylic acid-based, benzophenone-based, bendtriazole-based, and cyanoacrylate-based UV absorbers, and among them, a benzophenone-based benzotriazole-based absorber having an absorption wavelength near 400 nm is preferable from the viewpoint of its absorption wavelength characteristics. Specific preferred examples of the ultraviolet absorber include:
2,2'-dihydroxy-4-methoxybenzophenone, 2- (2'-hydroxy.3 ', 5'-di-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t- Butyl-5'-methylphenyl)-
5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole and the like can be mentioned. The absorption wavelength characteristics of these UV absorbers when finished into a filter differ depending on the amount added. That is, when the amount of the ultraviolet absorber is small, the absorption wavelength is on the short wavelength side, and when it is large, it is shifted to the long wavelength side. The amount of the UV absorber added may vary depending on the thickness of the UV cut filter finally obtained, etc.,
Usually 0.01 to 3% by weight is used, but preferably 0.1
~ 0.5% by weight. 2,2'-dihydroxy-4-
P added with 0.1 to 3% by weight of methoxybenzophenone
The transmittance curve of a 1 mm thick MMA plate is shown in FIG.

In the present invention, an ultraviolet cut plastic filter obtained by introducing a polymerizable group into the ultraviolet absorber and copolymerizing it with MMA may be used.

In the present invention, the ultraviolet cut filter is sealed in the artificial crystalline lens and is embedded so that the surface is not exposed.

To embed the UV cut filter in PMMA so that the surface is not exposed, first make a plate polymer of PMMA, place the UV cut filter on this, and then cover the UV cut filter with the MMA monomer. Polymerization may be performed by injecting. When the UV cut glass filter is embedded, the UV cut glass filter can be surface-treated with a silane coupling agent in advance to improve the adhesion to PMMA. More specifically, PM in a plastic container
An MA plate is put, a separately prepared ultraviolet cut filter is placed on the MA plate, and an MMA monomer added with a polymerization initiator is injected. After sealing the container and performing ordinary thermal polymerization,
By taking out the polymer from the container, a PMMA material containing a UV cut filter can be obtained. The lens portion of the artificial crystalline lens can be produced by cutting and polishing this material with a surface parallel to the ultraviolet cut filter surface, and then subjecting it to convex surface processing. Further, by a conventional method, if necessary, the position holes are processed, and the supporting portions are joined to complete the process. Thus, an artificial crystalline lens in which the ultraviolet cut filter is embedded as shown in FIGS. 1 and 2, that is, the ultraviolet cut filter is sealed with PMMA, is obtained.

<Operation> In the artificial crystalline lens thus produced, the ultraviolet cut filter is not exposed on the surface, so that the filter containing the ultraviolet absorber does not come into direct contact with aqueous humor. Therefore, no trouble is caused by elution of harmful ultraviolet absorbers. Further, even if the artificial crystalline lens surface is damaged by irradiation with YAG laser or the like in the treatment of subsequent cataract, it does not reach the filter and elution is not necessary.

<Example> MM purified by alkali washing, water washing, drying and distillation
98 parts by weight of A monomer, 2 parts by weight of purified ethylene glycol dimethacrylate, and 0.05 parts by weight of azobisisobutyronitrile as a polymerization initiator were sufficiently stirred and mixed to prepare a monomer solution. After injecting the monomer solution into a plastic cylindrical container and sealing it, polymerization was carried out in a water bath at 40 ° C. for 72 hours and further in a hot air dryer at a temperature rising schedule of 40 to 120 ° C. for 48 hours to obtain a PMMA material. Similarly, 2,2′-dihydroxy-4 was added to the monomer solution.
A mixture of 0.3 parts by weight of methoxybenzophenone was polymerized to obtain a PMMA containing an ultraviolet absorber. The PMMA material was cut and polished into a disk having an outer diameter of 9.9 mm and a thickness of 2 mm, which was placed in the bottom of a plastic container having an inner diameter of 10 mm. The above-mentioned PMMA containing the ultraviolet absorber is similarly cut and polished to prepare a disk-shaped UV cut filter having an outer diameter of 4 mm and a thickness of 0.3 mm, and the PMMA disk is placed with its central axes aligned. did. Further, the monomer solution was injected, and after confirming that there was no bubble, the container was closed. Similarly, polymerization was carried out in water and a hot air drier to obtain a button-shaped PMMA polymer containing a UV cut filter.

The polymerized portion was processed into a plano-convex lens having an outer diameter of 6 mm by a lathe according to a conventional method to prepare a lens having a UV cut filter embedded therein. Then, a position hole process and a supporting part joining process were performed to complete the artificial crystalline lens as shown in FIGS. 1 and 2.

The ultraviolet cut filter did not appear on the lens surface and end face, and was completely embedded in the artificial lens. When this artificial lens was irradiated with YAG laser in the air, damage was observed on the lens surface, but it did not reach the ultraviolet cut filter, and it was judged that there was no danger of elution.

<Effects of the Invention> According to the present invention, since the UV cut filter is embedded in the optically transparent PMMA, even if the surface of the optically transparent PMMA is slightly scratched, the internal Since it does not reach the ultraviolet cut filter, the ultraviolet absorber does not elute.

Therefore, the artificial lens obtained by the method for producing a harmful ultraviolet ray blocking artificial lens of the present invention, it is possible to give the artificial lens the ultraviolet absorption characteristics of a normal lens, a normal artificial lens having no ultraviolet absorbing function. Is susceptible to retinal damage, while the protective function of the retina is enhanced to the level of normal eyes. Moreover, unlike the conventional UV-cut artificial lens in which UV absorbers are distributed throughout the artificial lens, harmful UV absorbers do not elute from the surface, and after-treatment for cataract with YAG laser etc. It can be said that the function of the artificial lens is further improved even when the damage is caused to the eye without elution.

[Brief description of drawings]

FIG. 1 is a plan view of an artificial crystalline lens in which an ultraviolet cut filter obtained in an embodiment of the present invention is embedded, FIG. 2 is a side view, and FIG. 3 is 2,2'-dihydroxy-4-methoxybenzophene. It is the transmittance | permeability curve of the ultraviolet cut filter (thickness 1mm) which used non. 1 ... UV cut artificial lens, 2 ... UV cut filter, 3 ... Position hole, 4 ... Support part.

Claims (2)

[Claims] 1. An ultraviolet ray cut filter is disposed on an optically transparent polymethylmethacrylate, the ultraviolet ray cut filter is covered with an optically transparent methylmethacrylate monomer, and the methylmethacrylate monomer is polymerized to obtain the ultraviolet ray. A method for producing a harmful ultraviolet ray-cut artificial lens, which comprises sealing a cut filter. 2. The harmful ultraviolet ray blocking artificial crystalline lens according to claim 1, wherein the ultraviolet ray cutting filter is a glass filter containing an ultraviolet ray absorbing agent or polymethylmethacrylate containing an ultraviolet ray absorbing agent. Manufacturing method.