JPH0728910B2 - Intraocular lens material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a material for an intraocular lens, and more particularly to a material for an intraocular lens having good biocompatibility.

(Prior art and its problems) The intraocular lens that has been conventionally used as a lens for correcting vision after cataract surgery has been used in many clinical experiments in Japan in recent years with the improvement of lenses and the development of surgical techniques. Under,
Its use is increasing, and it has been recognized that it is functionally superior to conventional cataract glasses and contact lenses that have been generally used.

By the way, such an intraocular lens is an optical element (artificial lens) that is used as a substitute for a lens that has been surgically removed from the eye, and is inserted in the anterior chamber or posterior chamber of the eye. It is composed of a biconvex or plano-convex disc-shaped lens body and a support portion for holding the lens body at a predetermined position in the eye.

Polymethyl methacrylate has been mainly used as a material for the lens body and the supporting portion of the intraocular lens. This is because polymethylmethacrylate has also been widely used as a material for contact lenses.

However, in the intraocular lens made of this polymethylmethacrylate, although deterioration of the material itself does not easily occur, after insertion into the eye, various inflammatory cells and deposits are likely to appear around the lens. In addition, there is an inherent problem that fibrin is likely to be deposited and the subsequent cataract is likely to occur.

(Object of the Invention) Here, the present invention has been made in view of such circumstances, and an object of the present invention is to provide a material for an intraocular lens capable of correcting vision after cataract surgery. In particular, for intraocular lenses with good biocompatibility that suppresses surrounding cell reactions in the eye, specifically, various inflammatory cells, appearance of deposits, fibrin deposition, post-cataract, etc. To provide the material.

(Structure of the Invention) In order to achieve such an object, the present invention provides a material for an intraocular lens obtained by subjecting a copolymer containing methyl methacrylate and acrylic acid or methacrylic acid as a main component to an alkali treatment. It is what

(Operation / Effect) As described above, in the present invention, polymethylmethacrylate is not used as a material for an intraocular lens, and methylmethacrylate, which has a proven track record in terms of safety for living organisms, and charged A copolymer obtained by copolymerizing acrylic acid or methacrylic acid, which is a component, with an alkali treatment of the copolymer is used as a material for an intraocular lens. It is now possible to obtain a good intraocular lens of the reason, probably because the methyl methacrylate- (meth) acrylic acid type copolymer is charged by the alkali treatment. It is believed that.

For example, when methacrylic acid is used for the copolymerization with methyl methacrylate, the methacrylic acid component in the copolymer reacts with the alkali to form a salt form such as sodium methacrylic acid and the surface becomes charged. It is possible. Thus, since the chargeable material has little fibrin deposition and cell reaction, the chargeable copolymer according to the present invention as described above also suppresses the cell reaction in the surroundings in the eye to cause various inflammations. It is considered to be a material for an intraocular lens having good biocompatibility in which the appearance of cells and deposits, the deposition of fibrin, and the subsequent cataract hardly occur.

(Specific Configuration of the Invention) By the way, in the present invention, the copolymer to be subjected to the alkali treatment contains methyl methacrylate (A component) and acrylic acid or methacrylic acid (B component) as main components, and if necessary, It is composed of a cross-linking agent added in accordance with the above, and other vinyl-based monomers known as a copolymerization component of a lens material. Among them, the amount of the component B to be used is the above-mentioned components A and B. When the total amount of the components is 100 parts by weight, it is desirable that the ratio be within the range of approximately 3 to 30 parts by weight. If the amount of the component B used is less than 3 parts by weight, the effect of using the component B (biocompatibility) cannot be sufficiently obtained, and if it exceeds 30 parts by weight, the material becomes brittle and This is because the workability deteriorates. The term “main component” as used herein is generally abbreviated as long as it does not adversely affect the object of the present invention.
It should be understood that a proportion of 50% by weight or more is intended.

Further, the cross-linking agent is used in the same manner as in the case of producing a material for a normal lens, and specifically, the following commonly used monomers are exemplified, and one or two of these are used. More than one species are selected and used. Such a crosslinking agent is added for the purpose of imparting good shape stability to the material and insolubilizing the material in various solvents. The addition amount is preferably within the range of about 0.1 to 10 parts by weight with respect to 100 parts by weight of all the copolymer components. In addition, if an example of this crosslinking agent is given, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, allyl (meth) acrylate, Methacryloyloxyethyl acrylate, trimethylolpropane tri (meth) acrylate, divinylbenzene, diallyl phthalate, diallyl adipate, triallyl isocyanurate, and the like.

Then, the components A and B are mixed in a predetermined amount and, if necessary, various components such as a cross-linking agent, and if necessary, an appropriate amount of an additive such as a dye or an ultraviolet absorber is added. The copolymer, which is a raw material for the intended intraocular lens material, can be obtained by copolymerization according to a conventional method. In this copolymerization, the progress of polymerization is usually carried out by heating or irradiating with ultraviolet rays in radical polymerization, and in that case, a polymerization method such as a bulk polymerization method or a solution polymerization method is appropriately selected. The Rukoto. In order to carry out radical polymerization, radical polymerization initiator is added to a polymerization reaction liquid which is a mixed liquid obtained by mixing the above-mentioned various monomer components to carry out polymerization. Examples of this polymerization initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, benzoyl peroxide, and the like, and one or more of them are selected and used. In the case of heat polymerization, the temperature is gradually raised in the temperature range of approximately 20 ° C to 130 ° C, and the heating is performed for several hours to several tens of hours.
This completes the polymerization.

In addition, prior to the alkali treatment for providing the intraocular lens material according to the present invention, the above-mentioned copolymer will be molded into a desired intraocular lens member shape, particularly a lens shape. As the molding method at this time, the copolymer obtained by the above-mentioned polymerization method is cut into a desired shape in a dry state,
A technique such as polishing or pouring a mixed solution of the above-mentioned monomer components into a mold for polymerization, and molding at the same time as the polymerization is appropriately adopted. Further, in molding, after molding only the lens body, a supporting member may be attached to form an intraocular lens, or the lens body and the supporting member may be molded at the same time to form an integral intraocular lens. In the case where the present invention is applied to only the supporting member, only the supporting member is formed of the above copolymer.

Then, the material having a predetermined shape, which is made of the copolymer containing the above-mentioned component A and component B as the main component, is subjected to an alkali treatment so that at least the surface thereof is charged. However, this alkaline treatment is
Generally, it is carried out by using an alkaline solution of sodium hydroxide, potassium hydroxide or the like (preferably pH 13 or more) and immersing the material in the alkaline solution for a predetermined time. When the concentration of alkali in the alkaline solution is lower than 1%, it is difficult to obtain the desired effect.
When it exceeds 15%, the effect remains the same,
Since the workability is deteriorated, the concentration is generally about 1 to 15%. The immersion time is appropriately determined so as to obtain the desired effect, depending on the concentration of the alkaline solution, but it is generally about 15 to 2 hours.

The thus obtained material for an intraocular lens according to the present invention becomes a carboxylate in the form of a carboxylic acid salt by reacting the B component of the copolymer with an alkali by the alkali treatment as described above, and exhibits charging characteristics. Therefore, at least the surface exhibits a charged state, which suppresses the appearance of various inflammatory cells and deposits in the eye, makes it difficult for fibrin deposition and subsequent cataract to occur, and effectively acts on the surrounding cell reaction. It becomes a material for an intraocular lens which can be suppressed and has good biocompatibility.

(Examples) Hereinafter, several examples of the present invention will be shown to clarify the present invention more specifically, but the present invention does not impose any restrictions due to the description of such examples. Needless to say, it is not something to receive.

In addition to the following embodiments, the present invention is not limited to the above specific description, and various changes and modifications are made based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It is to be understood that improvements, etc. can be added.

In addition, all parts and percentages in the following examples are shown by weight unless otherwise specified.

Examples 1 to 4 First, a mixture of methyl methacrylate (MMA), methacrylic acid (MAA) and ethylene glycol methacrylate (EDMA) in various proportions shown in Table 1 below: 100 parts, and azo as a polymerization initiator Bisisobutyronitrile 0.
After mixing 1 part, pour into a polypropylene test tube and heat at a temperature of 35-50 ° C for 47 hours, then 110 ° C.
The temperature was raised to 21 hours, and the temperature was gradually raised to carry out the polymerization to produce various rod-shaped copolymers having different copolymerization ratios of the target components A and B.

Next, each of the obtained rod-shaped copolymers, in a dry state, was cut into a diameter of 3 mm and a thickness of about 0.2 mm, and then alkali-treated by immersing in a 10% aqueous sodium hydroxide solution for 30 minutes. After that, various test pieces corresponding to the intraocular lens material of the present invention were obtained by washing with physiological saline.

Then, the biocompatibility of each of the obtained test pieces was evaluated by the following test method. First, the test piece of the comparative example was transplanted to one eye of a rabbit, and the test piece of Example 1 was transplanted to the other eye of the rabbit so as to be located in the anterior chamber. Glutaraldehyde and 5% formalin mixture were used to fix the adherents attached to each test piece, and then, in a state of being immersed in physiological saline, using a stereoscopic microscope with a magnification of 32, a giant cell with a diameter of 100 μm or more The number of adhesion was measured. As a result, the number of cell-like adherents attached to the test piece of the comparative example was 33, whereas the number of adherents to the test piece of Example 1 was one, which is overwhelmingly superior to that of the test piece of the comparative example. As a result, the test piece of Example 1 according to the present invention was recognized to have excellent biocompatibility. Similarly, the test methods of Examples 2 to 4 were also applied to the test pieces to examine their biocompatibility, and all the test pieces had the same excellent biocompatibility. Was found to be

Claims (1)

[Claims] 1. An intraocular lens material obtained by subjecting a copolymer containing methyl methacrylate and acrylic acid or methacrylic acid as main components to an alkali treatment.