JP3801781B2 - Manufacturing method of intraocular lens - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, after extracting the crystalline lens in cataract, a method of manufacturing the intraocular lens to be inserted in place of the crystalline lens.
[0002]
[Prior art]
The intraocular lens is inserted in place of the lens removed during the cataract surgery. Since the first successful transplantation by Ridley in 1949, various studies have been conducted on its material and shape. In addition, various researches have been made in terms of materials, and accordingly, surgical methods have undergone major changes. Recently, with the spread of ultrasonic emulsification, etc., the incision required for lens extraction surgery such as removal of the turbid lens has become smaller, and the characteristics required for the inserted intraocular lens are also changing. is there.
For example, as disclosed in Japanese Patent Application Laid-Open No. 58-146346, a deformable intraocular lens having an optical part such as an elastic body appears, and is inserted into a eye from a small incision wound in a folded shape. And an insertion device for compressing or bending the deformable intraocular lens and inserting it into the eyeball is also disclosed.
[0003]
The intraocular lens material is gradually shifting from polymethyl methacrylate (PMMA), which requires an incision of about 6 mm, to a resin that can be restored after deformation, such as silicone and acrylic resin. In recent years, copolymers of hydroxyethyl methacrylate and methyl methacrylate, 2-hydroxyethyl methacrylate (HEMA), and the like have also been studied.
The shape of the intraocular lens is a material different from the circular optical part and having a loop-shaped support part, the loop-shaped support part is integrated with the optical part and the same material, the support part is a plate-like shape, etc. Various things have been researched and put into practical use.
The intraocular lens is manufactured by cutting a PMMA material into an intraocular lens shape by machining and buffing the optical part, tumbling agitation by stirring a plurality of intraocular lenses in an abrasive solution, Shifts to a molding method in which a material is polymerized or cross-linked in a mold to enable mass production.
[0004]
On the other hand, in the intraocular lens insertion method, the center of the anterior lens capsule is incised, the lens parenchyma and cortical fiber cells are removed by the ultrasonic emulsification suction method, etc., and then the intraocular lens is inserted into the capsule. The method is generalized.
Despite the improvement of the intraocular lens and the surgical method, the lens epithelial cells remaining after insertion of the intraocular lens are proliferated, and some of the proliferated lens epithelial cells are fibrillated toward the posterior capsule side. Sometimes. Usually, the fibrillated lens epithelial cells are clouded, which scatters the light transmitted through the posterior capsule side and lowers the light transmittance, so that there may be a post-cataract that reduces visual acuity.
These fibrotic lens epithelial cells generally proliferate gradually from the capsular equator to the center, and it is thought that the growth of the intraocular lens and other implanted plants and lens epithelial cells can be prevented from proceeding further. It has been.
[0005]
Hereinafter, the prior art of the intraocular lens 1 will be described with reference to FIGS. FIG. 13 is a cross-sectional view of the human eye 2 before the lens is extracted. The human eye 2 includes a cornea 3, an iris 4, a lens 5, a vitreous body 6, and a retina 7.
[0006]
Ultrasonic emulsification and suction, which is often performed at present, is performed by emulsifying and removing the substance with ultrasound while leaving the capsule 8 of the crystalline lens 5. The intraocular lens 1 is inserted when the lens 5 is completely removed. FIG. 14 shows this state.
Even after the lens 5 is removed by ultrasonic emulsification and the intraocular lens 1 is inserted, the cataract may occur due to proliferation of the lens epithelial cells 9 as described above. FIG. 15A is a sectional view showing the state. In this figure, in particular, the intraocular lens 1 manufactured by the tumbling method in which the optical part 1a is polished by putting the intraocular lens in a liquid containing abrasive grains and stirring is shown. The intraocular lens 1 is polished by bringing the entire surface into contact with the abrasive grains, and in particular, the corners are smoothed by the abrasive grains, and the optical part 1a and the outer peripheral part 10 have a continuous surface. It is common. Therefore, the contact angle between the intraocular lens 1 and the posterior capsule 8a becomes an obtuse angle, and the lens epithelial cells 9 that have proliferated from the vicinity of the capsular equator 11 to the posterior capsule 8a are on the back side in the optical part 1a of the intraocular lens 1 The shape is easy to penetrate. Therefore, there is a high possibility that secondary cataract is caused by cells grown in the optical part 1a.
[0007]
As shown in the cross-sectional view of FIG. 15 (b), the optical part 1a and the outer peripheral part 10 are constituted by discontinuous surfaces, and the lens epithelial cells are interposed between the optical part 1a and the posterior capsule 8a. Also disclosed is a shape that prevents 9 from growing.
In the intraocular lens 1 having such a shape, although it is prevented from growing in the optical part 1a, it may continue to grow in an irregular direction near the contact point between the intraocular lens outer peripheral part 10 and the posterior capsule 8a. And may enter into the optical part 1a over time and cause a subsequent cataract as in the above example.
[0008]
Based on this idea, the following methods are known as methods for preventing the lens epithelial cells 9 from proliferating to the lens optical part 1a. JP 8-317943, the intraocular lens in JP-A-9-173363 ported another ring-shaped member to the capsular bag, shows a method for implanting the intraocular lens, JP-A-8-257146 In the method of providing a protrusion around the optical part of the intraocular lens and preventing the proliferation of fibrotic cells by the contact angle between the protrusion and the posterior capsule of the lens, This shows a method in which a ridge is provided in the shape, and the lens epithelial cells 9 are prevented from growing to the optical part 1a of the intraocular lens 1.
[0009]
[Problems to be solved by the invention]
As described above, any of the methods for actively preventing secondary cataract is to add a planting plant for that purpose, to provide a protrusion on the intraocular lens optical part, and to provide a protrusion on the intraocular lens support part. This requires additional implants and complex processing for the conventional intraocular lens, and is more labor-intensive and more costly than conventional intraocular lens or intraocular lens insertion. Therefore, it had a problem of giving a load to the surgeon.
[0010]
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to form an optical portion of an intraocular lens and an outer peripheral portion thereof with discontinuous surfaces, and the outer peripheral portion is along a circumferential direction. The contact surface between the optical part of the intraocular lens and the posterior capsule has an acute angle, prevents the proliferating lens epithelial cells from entering the optical part, and the optical part by leaving the room to grow in a direction away from the one in which an object to provide a method for producing intraocular lenses that can enhance the effect of preventing secondary cataract.
[0012]
[Means for Solving the Problems]
The invention of claim 1 is constituted by a material having an elastic function, and is constituted by two optical surfaces joined by an outer peripheral portion, and is constituted integrally with the optical portion by the same material as the optical portion. In the method of manufacturing an intraocular lens having a peripheral part, the optical part and the first step of forming a shape larger than the final shape of the peripheral part integrally formed of the same material as the optical part, integrated with the same material A second step of pressurizing the peripheral portion in a direction substantially coinciding with the optical axis direction of the optical unit within an elastic deformation range, and a third step of processing the final shape in the pressurized state. Therefore, the intraocular lens according to the first aspect of the invention is a manufacturing method that realizes the intraocular lens without a step of finishing it into a final shape by additional processing such as cutting with a lathe, and is an intraocular lens formed larger than the final shape. The surrounding area Utilizing the deformation of the pressurizing resulting material, by cutting into a final shape in a deformed state, a method of producing an intraocular lens according to claim 1, to avoid costly due to an increase in man-hour The manufacturing method enables the optical part and the peripheral part of the optical part by using a characteristic characteristic of an intraocular lens having an elastic function.
[0012]
According to a second aspect of the present invention, there is provided an intraocular lens having an optical part composed of two optical surfaces joined by an outer peripheral part, or a peripheral part integrally formed with the optical part using the same material as the optical part. In the method, a first mold member that forms one of the two optical surfaces, a second mold member that is formed of an elastic material and forms the outer peripheral portion, and a third mold that forms the other optical surface. Using the mold member, and pressurizing the second mold member in a direction substantially coinciding with the optical axis of the optical unit to elastically deform the intraocular lens. In the case of a manufacturing method in which an intraocular lens material is poured into a mold, it is possible to mold a shape impossible with a normal inelastic body mold by removing the pressure after the molding is completed. According to the above, it is possible to suppress burrs generated during molding. , It is possible to omit the normal secondary processing step occurs.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION implementation form of the intraocular lens according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view of an intraocular lens of the present invention, FIG. 2 is a front view of FIG. 1, and FIG. 3 is an explanatory diagram showing a state in which the intraocular lens of the present invention is inserted into a lens capsule. FIG. 4 is an explanatory diagram showing the state of lens epithelial cell proliferation in a state where the intraocular lens of the present invention is inserted into the lens capsule.
[0014]
In the figure, reference numeral 20 denotes an optical part of the intraocular lens 1, which is formed of a transparent elastic body such as polymethyl methacrylate (PMMA) or silicone rubber. A pair of support portions 22 formed of different materials such as polyimide and PMMA for supporting the optical portion 20 in the eye are formed so as to protrude at opposing positions. The optical unit 20 has a configuration in which the optical surfaces 20 a and 20 b are coupled at the outer peripheral portion 21.
[0015]
The base end 22a of each support portion 22 is fixed to the vicinity of the outer peripheral portion 21 of the optical portion 20 by a support portion fixing pin 23, and each free end 22b is formed to be curved toward the optical portion 20 side, respectively. The optical part 20 can be positioned at the center in the lens capsule 8 by being deformed by elasticity. Reference numeral 24 denotes a concave shape that is continuous with the outer peripheral portion 21 of the optical portion 20 and is recessed toward the center of the distal end portion 20.
[0016]
The intraocular lens of implementation embodiment structured as described above, as shown in FIG. 3, when used in inserting the lens capsule within 8, as shown in FIG. 4, lens epithelial cells that have proliferated 9 can not only prevent the optical part 20 from entering the optical surface 20b of the optical part 20, but also leave room for growth in a direction away from the optical part 20, thereby enhancing the effect of preventing subsequent cataracts.
[0017]
5 and 6 show an intraocular lens 1 showing another embodiment of the present invention. In this intraocular lens structure, a support portion 25 is formed on the same surface peripheral portion 25a of the optical portion 20, and this support is shown. The optical part 20 of the intraocular lens 1 can be positioned at the central part in the crystalline lens capsule 8 by the part 25. In addition, small holes 26 penetrating the support portion 25 in the vertical direction are formed in the support portion 25 so as to sandwich the optical portion 20, and these small holes 26 and 26 are not shown but are made of a crystalline lens. By bringing the anterior capsule and the posterior capsule into contact with each other and promoting adhesion at an early stage, the intraocular lens 1 has a function of preventing the intraocular lens 1 from rotating within the lens capsule. Reference numeral 27 denotes a concave shape formed in the circumferential direction of the outer peripheral portion 27 a of the support portion 25.
[0018]
In the intraocular lens according to another embodiment of the present invention configured as described above, the proliferating lens epithelial cells enter the optical surface 20b of the optical unit 20 as in the case of the intraocular lens 1 according to the above-described embodiment. Of course, it is possible to leave room for growth in a direction away from the optical unit 20, and the effect of preventing subsequent cataracts can be enhanced.
[0019]
With respect to the intraocular lens according to the present invention, in the embodiment, the intraocular lens 1 having the support portion 22 molded with the molded member of the optical portion 20 and the different member, and in the second embodiment, the periphery of the same surface of the optical portion 20 Although the intraocular lens 1 having the support part 25 formed in the part 25a has been described, the present invention is not limited thereto, and the intraocular lens has a form in which the support part is integrally formed on both sides with the optical part interposed therebetween. Even if it is, if the concave shape is formed in the outer peripheral part of an optical part and a support part, of course, the effect similar to the above-mentioned embodiment can be acquired.
[0020]
Hereinafter, a preferred method for producing an intraocular lens used in the present invention will be described.
In order to realize the shape of the intraocular lens 1 of the present invention by molding as conventionally known, it is necessary to devise a molding mold part. When a general parting method is used, the outer peripheral portion of the intraocular lens 1 is used. Because of the concave shape, it is not preferable because the molded intraocular lens cannot be easily removed from the mold unless it is deformed.
In addition, if the tumbling polishing is performed after the outer peripheral portion is first processed into a concave shape, the connection point between the outer peripheral portion and the optical surface of the optical portion becomes a continuous surface, and the lens epithelial cells are prevented from growing in the optical portion. This reduces the effect of the present invention.
[0021]
Therefore, in order to manufacture the intraocular lens of the present invention, after the optical surface is polished and formed by the conventional molding method, buffing and tumbling polishing, the outer peripheral portion is secondarily processed by a known processing method such as machining. Therefore, it is necessary to finish the shape of the present invention, thereby increasing the number of steps.
[0022]
Therefore, a method for manufacturing the intraocular lens shown in FIGS. 1 to 6 without increasing the number of steps will be described below with reference to FIGS.
7 and 8 show a first embodiment of the method for manufacturing the intraocular lens 1 of the present invention. In the first embodiment, a manufacturing method for molding the intraocular lens 1 in which the optical unit 20 is formed of an elastic body will be described.
[0023]
The first process is a step of manufacturing a primary processed product having a larger shape than the final shape 30 as shown by a broken line in FIG. 7 by a known method for manufacturing an intraocular lens in which at least the optical unit 20 is formed of an elastic body. is there. FIG. 7 shows an example in which the optical unit 20 and the support unit 25 shown in FIG. 6 are integrated with the same material. The primary processed product has an optical portion 20 and small holes 26 already formed, and has a shape having a support portion 28 larger than the final shape 30 indicated by a broken line.
[0024]
As shown in FIG. 8, the second process is a step of uniformly pressing the peripheral portion 25 a of the optical unit 20 by the upper mold 31 and the lower mold 32 in a direction substantially perpendicular to the optical axis. The applied pressure in this step is within a range in which at least the elastic body including the optical unit 20 can be elastically deformed.
Further, the pressurizing part is only the support part 25 including the peripheral part 25a of the optical part 20, and in order to release internal stress by deformation of the elastic body, as shown by the arrow 33 in the figure, pressurization is performed only in the vertical direction. The horizontal direction and the vertical direction of the drawing are released so as to be freely deformable.
[0025]
In this way, by applying pressure in one direction within the elastic deformation range, the shape of the support portion 25 formed of an elastic body is deformed so as to be a convex shape 29 such as a cross-sectional shape at an end portion where no pressure is applied. .
[0026]
The third process is a step of processing into the final shape 30 while applying pressure. FIG. 8 shows processing by cutting as an example. A die 34 having the same shape as the final processed shape 30 of the intraocular lens 1 moves along the upper and lower dies 31 and 32 to the position of the lower two-dot chain line to cut the large support 28 of the intraocular lens 1. Shows the processing method. And after final shape processing is completed, the pressure from the up-and-down direction to upper and lower molds 31 and 32 is canceled.
[0027]
As described above, since the applied pressure is within a range where the elastic body can be elastically deformed, the elastic body returns to its original shape by releasing the pressure. On the other hand, the outer peripheral portion 27a that was pressed during the final shape processing was deformed into the convex shape 29 toward the periphery of the mold due to the pressure. Therefore, when the pressure is removed, the processing surface is reversed when the original shape is restored. A concave shape 27 is formed.
[0028]
In other words, the shape of the outer peripheral portion 27a after the pressure removal is a concave shape 27 that is discontinuous with the support portion 25 and is uniformly recessed along the circumferential direction, as shown in FIG.
In the present embodiment, the manufacturing method of the intraocular lens 1 in which the optical unit 20 and the support unit 25 are configured by the same elastic body as shown in FIGS. 5 and 6 has been described. However, the present invention is not particularly limited to this mode. A method of manufacturing the optical part 20 of the intraocular lens as shown in FIGS. 1 and 2 in which only the optical part 20 is made of an elastic body is also possible.
[0029]
9 and 10 show a second embodiment of the method for manufacturing an intraocular lens of the present invention.
As shown in FIG. 9, this manufacturing method is made of a material having an elastic function for forming an upper mold 31 for forming one optical surface 20a, a lower mold 32 for forming the other optical surface 20b, and an outer peripheral portion 27a. Manufactured using the three mold members of the medium mold 35 constructed.
FIG. 10 is a plan view of the middle die 35 made of a material having an elastic function, such as synthetic rubber, as viewed from above in FIG. Thus, the middle die 35 has a hole 36 having a shape close to the final shape 30 of the intraocular lens 1, and has a structure in which the outer peripheral portion 27a of the intraocular lens is formed on the surface in the thickness direction.
The thickness of the middle die 35 is formed to be thicker than the thickness of the outer peripheral portion 27a of the intraocular lens 1 by a range Δd that can be elastically deformed.
[0030]
FIG. 9 shows a state in which the intraocular lens 1 is being molded. As shown by an arrow 33 in the drawing, the upper mold 31 and the lower mold 32 are pressurized to a predetermined pressure from the vertical direction. As shown in the drawing, the end of the middle die 35 is deformed into a uniform convex shape 36 in the horizontal and vertical directions where the stress is released by pressurization. Further, although the middle die 35 is deformed by pressure, although not shown, a minute gap formed between the upper and lower dies 31 and 32 and the middle die 35 can be filled by the middle die 35 being deformed.
[0031]
For this reason, according to the manufacturing method of the present invention, a burr that cannot be avoided by molds made of a plastic material such as a metal also functions as a so-called packing because the middle die 35 is deformed. Is possible.
In particular, in the case of intraocular lens materials with a low viscosity of the raw material, the mold is conventionally made of a plastic material such as metal, and even if precision finishing is performed, the material wraps into a very small gap, eliminating burrs. I couldn't. Therefore, secondary processing for eliminating burrs was necessary, but the work of the secondary processing could be omitted by the development of the middle die 35.
[0032]
The intraocular lens material of the present invention is injected by a predetermined amount before the upper and lower molds 31 and 32 are combined. After the upper and lower molds 31 and 32 are combined, the material is put into the mold from the gate not shown in the drawing. It is formed by a known method such as injection.
When the upper mold 31 and the lower mold 32 are opened again after the molding is completed, the middle mold 35 returns to the original shape. Therefore, even if the outer peripheral portion 27a of the molded intraocular lens 1 is molded into the concave shape 27, the middle mold 35 is restored. Can be taken out without interference.
[0033]
FIGS. 7 to 10 show an example of manufacturing the intraocular lens 1 in which the optical unit 20 and the support unit 25 are made of the same material as shown in FIGS. 5 and 6, but the invention is particularly limited to such a form. Is not to be done.
[0034]
FIGS. 11 and 12 show manufacturing examples of the intraocular lens 1 in which the optical unit 20 and the support unit 22 are made of different members and different materials as shown in FIGS.
Also in this manufacturing method, similar to the method shown in FIGS. 9 and 10, the upper and lower molds 31 and 32 and the middle mold 35 having an elastic function are used for manufacturing. By pressing the lower dies 31 and 32 in the vertical direction of the arrow 33, the middle die 35 is pressed and deformed, and the concave shape 24 can be easily formed along the circumferential direction of the outer peripheral portion 21 of the optical portion 20 as in the above-described embodiment. Can be formed.
[0035]
Moreover, according to this manufacturing method, the intraocular lens 1 to be molded is not limited to an elastic material, and can be manufactured even with a so-called hard material such as a conventional PMMA.
Furthermore, in the present embodiment, the method for manufacturing an intraocular lens as shown in FIG. 5, FIG. 6 or FIG. 1 and FIG. 2 is shown, but the intraocular lens in which the loop-shaped support portion is composed of the same member as the optical portion. Obviously, it can also be applied to lenses.
[0036]
【The invention's effect】
As described above, the manufacturing method of the intraocular lens according to the invention of the present patent application is a manufacturing method for realizing the intraocular lens according to inventions without grooving additional outer peripheral portion, such as cutting by a lathe, Deformation utilizing deformation of the material caused by pressurizing the support part including the peripheral part using the properties unique to the intraocular lens in which the optical part and the peripheral part of the optical part have an elastic function when manufacturing the intraocular lens Since it is a manufacturing method which processes into a final shape in a state, there is an effect that it can be manufactured while avoiding high costs due to an increase in man-hours.
[0037]
In addition, the manufacturing method of the intraocular lens according to the invention is a manufacturing method in which the intraocular lens is formed by pouring the intraocular lens material into the mold, and the mold member that forms the outer peripheral portion is formed of an elastic body. Molding is performed after the mold member is deformed under pressure, and after the molding is completed, the pressure can be reduced to form a shape that is impossible with a normal inelastic mold, and the burrs that occur during molding can be suppressed. There is an effect that the next processing step can be omitted.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of an intraocular lens of the present invention.
FIG. 2 is a front view of the intraocular lens of FIG.
FIG. 3 is an explanatory diagram showing a cross-section in a state where the intraocular lens of the present invention is inserted into a human eye.
FIG. 4 is an explanatory diagram showing the state of lens epithelial cell proliferation in a state where the intraocular lens of the present invention is inserted into the lens capsule.
FIG. 5 is a side view showing another embodiment of the intraocular lens of the present invention.
6 is a front view of the intraocular lens of FIG. 5. FIG.
FIG. 7 shows an intraocular lens formed by an intermediate process according to the intraocular lens manufacturing method of the present invention.
FIG. 8 is a sectional view showing a first embodiment of the method for producing an intraocular lens of the present invention.
FIG. 9 is a sectional view showing a second embodiment of the method for producing an intraocular lens of the present invention.
FIG. 10 is a plan view of some molds used in the second embodiment of the method for manufacturing an intraocular lens of the present invention.
FIG. 11 is a cross-sectional view of another embodiment according to the second embodiment of the intraocular lens manufacturing method of the present invention.
FIG. 12 is a plan view of a part of a mold used in another embodiment according to the second embodiment of the intraocular lens manufacturing method of the present invention.
FIG. 13 is an explanatory diagram showing a cross section of a human eye.
FIG. 14 is an explanatory view showing a state in which a conventional intraocular lens is inserted into a crystalline lens capsule.
FIG. 15A is an explanatory view showing the state of lens epithelial cell proliferation in a state where a conventional intraocular lens is inserted into a lens capsule. (B) is explanatory drawing showing the mode of lens epithelial cell proliferation in the state which the conventional improved intraocular lens was inserted in the lens capsule.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Intraocular lens 3 Cornea 4 Iris 5 Lens 6 Lens 6 Retina 8 Sac 9 Lens epithelial cell 20 Optical part 21 Peripheral part 22 Support part 24 Concave shape 25 Support part 26 Small hole 27a Peripheral part 27 Concave shape 30 Final top 31 Mold 32 Lower mold 34 Draw mold 35 Medium mold

Claims (2)

  An intraocular lens having an optical part composed of two optical surfaces made of a material having an elastic function and joined by an outer peripheral part, and a peripheral part made of the same material as the optical part and integrally formed with the optical part In the manufacturing method, the first step of forming the optical part and a shape larger than the final shape of the peripheral part integrally formed of the same material as the optical part, the peripheral part integrated with the same material Manufacturing of an intraocular lens, comprising: a second step of applying pressure within an elastic deformation range in a direction substantially coincident with the optical axis direction of the optical unit; and a third step of cutting into a final shape in the pressurized state. Method.   In the method of manufacturing an intraocular lens having an optical part composed of two optical surfaces joined by an outer peripheral part, or a peripheral part integrally formed with the optical part using the same material as the optical part, the two optical A first mold member that forms one of the surfaces, a second mold member that is formed of an elastic material and forms the outer peripheral portion, and a third mold member that forms the other optical surface, A method of manufacturing an intraocular lens, comprising: pressing the mold member 2 in a direction substantially coinciding with the optical axis of the optical unit to elastically deform the mold member.

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