JPH0555294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing an intraocular lens. More specifically, the present invention relates to a method of manufacturing an intraocular lens in which an optical part and a support part are integrally molded.

[Prior Art] An intraocular lens is composed of a lens body and a support part. Conventionally, the lens body and the support part have been separate parts, and the intraocular lens has been constructed by assembling these parts, or the lens body and the support part have been separate parts. There are some that are integrally molded with the support part.

In an intraocular lens constructed by assembling a lens body and a support part, when an attachment hole for providing the support part in the lens body is provided using a drill, etc., the diameter of the attachment hole is usually approximately Because it is extremely small (0.1 to 0.25 mm), it is difficult to adjust the diameter of the mounting hole, and the work of assembling the lens body and support part is complicated, so the size and shape of the support part and the mounting angle of the lens body are difficult. It is said that it is difficult to obtain an intraocular lens with excellent precision.

The following three manufacturing methods have generally been proposed as methods for manufacturing intraocular lenses in which a lens body and a support portion are integrally molded.

(b) An injection molding method in which an uncrosslinked material is injected into a mold having the shape of a completed intraocular lens, in which the lens body and support part are integrated.

(b) An in-mold polymerization method in which a monomer is injected into a mold having the shape of a completed intraocular lens in which a lens body and a support part are integrated, and then the monomer is polymerized and molded.

(c) A cutting method in which intraocular lens material is cut using a precision processing machine such as a carving machine to produce an intraocular lens having a desired shape.

However, when the above-mentioned (a) injection molding method is adopted, uncrosslinked polymethyl methacrylate is used as the material for the intraocular lens used in this method, and the obtained intraocular lens is not biocompatible. However, there are problems in that in vivo deterioration is likely to occur and the YAG laser resistance may also be reduced. When the above-mentioned (b) mold polymerization method is adopted, there is a problem that shrinkage may occur during polymerization, making it impossible to obtain a desired shape and size, especially in thin or thin parts such as the support part. There is a point. Further, when the above-mentioned cutting method (c) is adopted, there is a problem that the processing becomes complicated, especially when the shape of the support part is complicated, and the workability is reduced.

[Problems to be Solved by the Invention] Therefore, the present inventors have conducted intensive research to find an intraocular lens that can solve the above-mentioned problems, and as a result, they have developed an intraocular lens that has a desired shape and size. The present invention has been completed by discovering a completely new method for manufacturing intraocular lenses that allows intraocular lenses to be easily manufactured with high precision, and in which the resulting intraocular lenses have excellent biocompatibility and minimal in-vivo deterioration. It came to this.

[Means for Solving the Problems] That is, the present invention provides a method for injecting a monomer into a mold having a concave portion provided with a groove on the lower surface corresponding to the shape of an intraocular lens in which a lens body and a support portion are integrated. After making an intraocular lens block by injecting
The present invention relates to a method for manufacturing an intraocular lens, characterized in that the mold is cut together with the intraocular lens block so that the lens body and the rear surface of the support part form the same plane or the same spherical surface.

[Operations and Examples] According to the method for manufacturing an intraocular lens of the present invention, a mold having a concave portion provided with a groove on the lower surface corresponding to the shape of an intraocular lens in which a lens body and a support portion are integrated. After injecting a monomer into the intraocular lens block, the mold is cut together with the intraocular lens block so that the lens body and the rear surface of the support part form the same plane or the same spherical surface. This results in an intraocular lens.

Examples of the material for the mold used in the present invention include polyolefins such as polyethylene and polypropylene, copolymers of these polyolefins, polyacetal, and polyphenylene sulfide.

For example, when molding an intraocular lens having a shape in which the lens body 4 and the rear surface 16 of the support portion 5 form the same plane as shown in FIG. 2b, the mold is similar to that of the mold shown in FIG. 1. As shown in the schematic cross-sectional view, the mold body 1 is composed of a mold body 1 having a recess 3 in which a groove 4a having the shape of a lens body 4 and a groove 5a having the shape of a support portion 5 are provided on the lower surface, and a lid portion 2.

In addition, in order to prevent the lens body 4 from coming into contact with the iris or the posterior lens capsule when the intraocular lens is installed in the eye, the rear surface of the lens body 4 and the support part 5 should be aligned, for example, as shown in FIG. When molding an intraocular lens having the same spherical shape, a groove 4a having the shape of the lens body 4 and a groove having the shape of the support part 5 are used, as shown in the schematic cross-sectional view of the mold in FIG. 3b. It is preferable to use a mold body 1 having a recess 3 with a recess 5a provided on the lower surface.

In FIG. 1, the depth h from the bottom surface of the lid part 2 to the bottom surface of the recess 3 of the mold body 1 is determined by the depth h, which is calculated by filling the recess 3 with the monomer raw material and assuming that shrinkage or distortion occurs when the monomer raw material is polymerized. Even in such cases, it is sufficient that the depth is such that these contractions and distortions do not particularly affect the lens body 4 or the support portion 5, and the depth is usually 4.
Adjusted to be at least mm. Furthermore, as shown in FIG. 1, if a through hole 6 is provided in the lid part 2 to serve as a reservoir for the monomer raw material, even if shrinkage occurs during polymerization, the monomer in the through hole 6 will be filled into the void created. It is preferable that the concave portion is always filled with the monomer by flowing into the concave portion, thereby preventing the occurrence of shrinkage or distortion.

In addition, according to the manufacturing method of the present invention, the second a
In addition to intraocular lenses having shapes as shown in FIGS. 5 and 4, intraocular lenses having shapes as shown in the schematic perspective views of FIGS. 5 to 12, for example, can be obtained.

5, 6, and 7 are schematic perspective views of an intraocular lens in which the lens body 4 and the loop-shaped support portion 5 are integrated, and FIGS. 8 and 11 are schematic perspective views of the lens body 4 and the plate-shaped support portion 5. FIG. 9 is a schematic perspective view of an intraocular lens that integrates the lens body 4 and the ring-shaped support 5, and FIG. 10 shows the lens body 4. and L-shaped support part 5
Schematic perspective view of an intraocular lens integrated with the 12th
The figure is a schematic perspective view of an intraocular lens in which a ring-shaped support portion 5 is integrated with two pairs of lens bodies 4.

The shape of the support part 5 may be either plate-like or loop-like as described above, but the thickness of the support part 5 is preferably 0.15 mm or more when the support part 5 is plate-like.
0.2 mm or more, and for loop-shaped ones, where a is the thickness of the loop in the lens thickness direction and b is the width of the loop in the lens radial direction, a/b is 1 or less, and a is A thickness of 0.15 mm or more, especially 0.2 mm or more is preferable in terms of formability, that is, in order to obtain a support portion 5 having a desired shape and excellent surface accuracy.

Monomer raw materials used in the present invention include (meth)acrylate monomers such as hydroxyethyl (meth)acrylate, methyl (meth)acrylate, allyl (meth)acrylate, N
Examples include vinylpyrrolidone and dimethylacrylamide.

Next, the manufacturing process of the intraocular lens will be explained.

As shown in FIG. 1, the lid 2 is attached to the mold body 1.
is attached, the monomer raw material for the ophthalmic lens described above is injected between the mold body 1 and the lid 2, and the monomer is polymerized to produce an intraocular lens block. In addition, when polymerizing the monomer,
In order to obtain an intraocular lens with high solvent resistance and excellent shape stability, crosslinking monomers such as ethylene glycol dimethacrylate, allyl methacrylate, trimethylolpropane trimethacrylate, divinylbenzene, diallyl phthalate, etc. are used as the monomers. 10 to 100 parts by weight
It is preferable to add in an amount not exceeding parts by weight. In addition, in order to initiate the polymerization of the monomers, a radical polymerization initiator, which is commonly used in the polymerization of unsaturated hydrocarbon compounds such as benzoyl peroxide, azobisisobutyronitrile, and azobisdimethylvaleronitrile, is added to the monomers. It is preferable to add 0.01 to 1.0 parts by weight based on the weight part.

After the monomer is injected into the mold, it is polymerized by a conventional photopolymerization method, heat polymerization method, radiation polymerization method, etc., and then cooled to room temperature.

Next, the intraocular lens block obtained as described above is processed according to the steps shown in FIG. 13 or 14, which are schematic illustrations of the manufacturing method of the present invention, to produce an intraocular lens. be done.

That is, FIG. 13 shows a method for manufacturing an intraocular lens having a shape in which the lens body 4 and the rear surface of the support part 5 are on the same plane, and FIG. Each method of manufacturing an intraocular lens having a spherical shape is shown.

In FIG. 13, 8 is a chuck, 9 is a bite, 10 is an intraocular lens block, and 11 is an intraocular lens.

The produced intraocular lens block 10 is manufactured by sandwiching the mold body 1 between the chucks 8, rotating the chucks 8 about the central axis A, and inserting the bite 9 into the mold body 1, as shown in step () in FIG. By moving the mold body 1 straight in the direction of the arrow 19, the mold body 1 is cut until the thickness of the supporting portion becomes approximately 0.3 to 0.7 mm, resulting in the state shown in step (). In addition, it is necessary to prevent the intraocular lens portion of the intraocular lens block 10 from being distorted by the stress caused by the pressure of the cutting tool 9 during cutting, and at the same time to prevent the intraocular lens block 10 from detaching from the mold body 1 during cutting. In order to prevent this, it is preferable that the intraocular lens block is provided with protrusions 14 at at least two locations, as shown in FIG. Although the shape of the protrusion 14 is arbitrary, it is preferable that the length is 0.5 mm or more, the diameter is 1.0 mm or more, and it is separated from the intraocular lens part 15 by 1.5 mm or more.

As a method for providing the protrusion 14, it is preferable to form a recess in advance on the lower surface of the recess 3 of the mold body 1.

The cut surface of the intraocular lens block 10 obtained by cutting is polished to the desired thickness of the support part by a conventional method, resulting in the state shown in step () in FIG. The intraocular lens 11 is then released from the mold body 1, and as shown in the steps, an intraocular lens 11 having a desired shape is produced and put into use.

Furthermore, a method for manufacturing an intraocular lens having a shape in which the lens body 4 and the rear surface of the support portion 5 form the same spherical surface will be explained based on FIG. 14.

The manufactured intraocular lens block 10 is manufactured by sandwiching the mold body 1 between the chucks 8, rotating the chucks 8 about the central axis A, and moving the bite 9 in the direction of the arrow 17, as shown in step (). Walk straight ahead and remove lid part 2. Next, as shown in step (), the tool bit 9 is turned in the direction of the arrow 18, and the intraocular lens block 10 is shaped into a spherical or aspherical shape so that the thickness of the support part is about 0.3 to 0.7 mm.
Cut until . The cut surface of the obtained intraocular lens block 10 is polished by a conventional method to the desired thickness of the support part, and the state shown in step () is obtained.
The intraocular lens 11 is then released from the mold body, and as shown in the step, an intraocular lens 11 having a desired shape is produced and put into use.

In FIGS. 13 and 14, the intraocular lens 11 can be released from the mold by applying pressure to the side surface of the mold body 1 or the jig 13 with a finger or by placing it in an alkaline aqueous solution such as sodium carbonate or caustic soda. A method such as immersion for a certain period of time can be adopted.

Note that the end surface of the supporting portion of the obtained intraocular lens 11 has an acute angle, and in order to prevent damage to the ocular tissue during use, for example, barrel polishing or mechanical polishing with cloth, film, etc. It is preferable to perform Among these polishing methods, barrel polishing is particularly preferred in consideration of its efficiency. In addition, when polishing the support part, use adhesive tape or a cap in advance to polish the lens body 4.
Masking is advantageous because the planar accuracy of the lens body 4 is not impaired and the workability of polishing is further improved.

Next, the method for manufacturing an intraocular lens of the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

Example 1 100 parts by weight of methyl methacrylate, 3 parts by weight of ethylene glycol dimethacrylate and 0.1 part by weight of azobisisobutyronitrile were stirred to obtain a uniform composition to obtain a monomer mixture.

Next, the monomer mixture obtained in the polypropylene mold shown in FIG. 1, which has the molded shape of the intraocular lens block shown in FIGS. 16a and 16b, is injected to form the upper surface of the lid part 2. Ultraviolet rays were irradiated from the side of the mold body 1 to polymerize the monomer.

Next, the lid part 2 is removed and attached to the chuck of the lens cutting machine, and while the chuck is rotated,
A cutting tool was applied to the side surface of the mold body 1, and cutting was performed so that the thickness of the support part was 0.50 mm, and then polished to 0.20 mm to obtain an intraocular lens.

Next, remove the mold body 1 from the chuck,
The side surface of the mold body 1 was pressed with a finger to release an intraocular lens having a desired shape.

After covering the obtained intraocular lens body with cellophane adhesive tape and performing barrel polishing on the supporting part, the adhesive tape was removed and the appearance of the intraocular lens was inspected with a magnifying glass, and it was found that there were no sharp edges on the supporting part. It had a smooth surface with rounded corners and a smooth back surface of the lens body, which had a desired shape.

Next, when the refractive power of the intraocular lens obtained was examined using a lens meter, it was found to be +19.0 diopters.

Example 2 90 parts by weight of 2-hydroxyethyl methacrylate, 10 parts by weight of methyl methacrylate, 0.2 parts by weight of ethylene glycol dimethacrylate and 0.1 part by weight of azobisisobutyronitrile were stirred to obtain a uniform composition to form a monomer mixture. I got it.

Next, the procedure of Example 1 was repeated except that the monomer mixture obtained in the polypropylene mold shown in FIG. 1 having the intraocular lens shape shown in FIGS. 17a and 17b was injected into the eye. An inner lens was made.

The obtained intraocular lens had no sharp edges on the supporting part and had a rounded and glossy surface, and the back surface of the lens body was also smooth and had the desired shape.

Next, the intraocular lens was swollen with physiological saline, and its refractive power was examined in the same manner as in Example 1, and it was found to be +20.0 diopters.

[Effects of the Invention] According to the manufacturing method of the present invention, shrinkage and distortion are prevented from occurring when monomers are polymerized, and an intraocular lens having a desired shape and extremely high surface precision can be efficiently manufactured. Therefore, even an intraocular lens having a support portion having a particularly complicated shape can be manufactured very easily.

Furthermore, since a crosslinked polymer can be used in the manufacturing method of the present invention, an intraocular lens with little deterioration in vivo can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a mold used in the manufacturing method of the present invention, and FIGS. 2a and 4 are views of intraocular lenses manufactured using the molds shown in FIGS. 1 and 3b, respectively. Schematic perspective view, Figure 2b is a side view of the intraocular lens shown in Figure 2a, Figure 3a
The figure is a plan view of the mold used in the manufacturing method of the present invention, FIG. 3b is a schematic sectional view taken along the line A-A in FIG. 3a,
5 to 12 are schematic perspective views showing one embodiment of the support loop according to the present invention, FIGS. 13 and 14 are schematic illustrations showing the manufacturing method of the present invention, and FIG. 15 is a schematic perspective view showing an embodiment of the support loop according to the present invention. A schematic perspective view of an intraocular lens block obtained by the manufacturing method of the invention, in which a protrusion is provided;
Figures 16a and 16b, Figures 17a and 17b
The figures are explanatory views showing the shapes of intraocular lens blocks obtained in Example 1 and Example 2 of the present invention, respectively. Main symbols in the drawings: 1...Mold body, 2...Lid portion, 3...Concave portion, 4...Lens body, 5...Support portion, 10...Intraocular lens block, 11...Intraocular lens.

Claims (1)

[Claims] 1. An intraocular lens block is produced by injecting a monomer into a mold having a concave portion on the lower surface with a groove corresponding to the shape of an intraocular lens in which a lens body and a supporting portion are integrated. After manufacturing the intraocular lens, the mold is cut together with the intraocular lens block so that the lens body and the rear surface of the support part form the same plane or the same spherical surface. 2. The method for producing an intraocular lens according to claim 1, wherein the lid of the mold has a through hole that connects the outside air to the inside of the mold.