JPH04132547A - Balloon type internal lens - Google Patents

Abstract

PURPOSE:To enable the correction of visual acuity of a patient by using a lens made up of a balloon molded by a resin which transmits light and whose tensile elastic modules exceeds a specified value and a light transmitting filler with which the balloon is filled. CONSTITUTION:A balloon type internal lens 10 is made up of a balloon 12 and a filter 14 for filling the balloon 12. The balloon 12 is a hollow body which is molded with a resin (e.g. PET) which transmits light and is low in expandability with a tensile elastic modulus exceeding 2kgf/mm<2>. It has a check valve 16, and the thickness of a sheet forming the hollow body is bellow 50mum, about 1mum-20mum to facilitate the folding thereof when it is inserted into an eye. The internal lens 10 is formed smaller by winding or the like to be implanted into the eye by surgery after the extraction of a crystal lens. Then, the filler 14 is injected into the hollow body in the eye and thus, an internal lens 10 is made finally to act as a lens in place of the crystalline lens.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a balloon-type intraocular lens used for correcting visual acuity after surgery for cataract or the like.

<Prior art> Intraocular lenses (Intraocular lenses;
0L) is a lens that is implanted into the eye in place of the crystalline lens for the purpose of correcting visual acuity after surgically removing the crystalline lens that has been damaged by cataracts, trauma, etc.
0 Since Ridley implanted an artificial lens (artificial crystalline lens) into the eye in 1949, there have been repeated improvements in lens materials, designs, and surgical methods, and today intraocular lens implantation is no longer possible. , is routinely used to treat cataracts, etc. In addition, regarding lens fixation methods during intraocular lens implantation, anterior chamber fixation, iris fixation,
Retrograde fixation has been attempted, but currently, retrograde fixation,
Particularly preferred is a method in which the lens is fixed within the lens capsule after lens extraction.

By the way, in order to remove a crystalline lens that has become cloudy due to cataract and insert and fix (transplant) an intraocular lens into the lens capsule instead, it is necessary to surgically incise the conjunctiva, sclera, and the like.

Conventionally, poly(intraocular lenses) were made of polymethyl methacrylate (
PMMA).

Although PMMA is lightweight and has excellent optical properties, it is hard and cannot be deformed when molded into a lens.

Here, since a PMMA intraocular lens usually has a size of 6 ml or more, 61 or more incisions are required to insert the PMMA intraocular lens into the eye.

On the other hand, one method for removing the cloudy crystalline lens from within the eye is phacoemulsification (facoe+++u-・1s
According to this method, it is possible to remove the crystalline lens through approximately 31 incisions.

In other words, when applying a PMMA intraocular lens,
3II1m for the amount of incision required to remove the crystalline lens
One or more large incisions are required.

However, it is preferable that the incision during surgery be smaller, and by making the incision smaller, it reduces postoperative astigmatism, reduces the possibility of postoperative complications such as infection,
Furthermore, it has many advantages, such as healing of the incision wound in a short period of time. For this reason, various intraocular lenses have been proposed that can be inserted through smaller incisions than conventional ones.

<Problem to be solved by the invention> Concerning an intraocular lens that can be inserted through a small incision 1 For example, US Pat. However, the problem remains that this lens rapidly restores its original shape after being implanted into the eye, which tends to destroy surrounding microscopic cells.
Additionally, US Pat. No. 4,556.998 discloses an intraocular lens made of hydrogel that swells within the eye after being inserted into the eye, but this lens absorbs the surrounding aqueous humor. As a result, components of the aqueous humor are concentrated, causing problems such as denaturation and adsorption of proteins, and also problems such as the need for a considerable amount of time to sufficiently swell to a complete shape.

On the other hand, Japanese Unexamined Patent Publication No. 64-32859 discloses a balloon-type intraocular lens made of a balloon made of an elastomer. This intraocular lens is made by inserting a folded balloon into the eye and then filling the inside of the balloon with an injectable material to form a lens in a predetermined shape. However, in order to achieve and maintain accurate lens performance by filling the inside of an elastomer with rubber elasticity, it is necessary to use a thin balloon (and a completely uniform wall thickness considering the elongation rate of the elastomer). In addition, since the elastomer used in this intraocular lens has an elongation rate of over 100%, it is difficult to adjust the amount of injection material, and it is difficult to adjust the amount of injection material. There are problems such as the lens does not have a predetermined shape and the lens power does not match.

Furthermore, since the inside of the balloon is pressurized, in the event that it ruptures, the injected material may suddenly squirt out, potentially destroying the surrounding tissue. ing.

An object of the present invention is to solve the problems of the prior art described above, and to provide a balloon-type intraocular lens applied to the treatment of cataracts, etc., which is inserted into the eye through a small incision after the natural crystalline lens is extracted. It can be inserted into the eye, has no adverse effect on surrounding tissues, and has little deviation (
An object of the present invention is to provide a balloon-type intraocular lens that can be easily and accurately formed into a predetermined shape to appropriately correct a patient's visual acuity.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a balloon molded from a plastic that is transparent to light and has a tensile modulus of elasticity of 2 kgf/m2 or more; A balloon-type intraocular lens is provided, which is comprised of a light-transmissive filling material.

Further, it is preferable that the balloon can be inserted into the eye through an incision hole of 3' and 5 mm or less formed in the sclera by folding the balloon.

Further, it is preferable that the plastic is polyethylene terephthalate.

Further, it is preferable that the thickness of the plastic is 50 μm or less.

It is also preferred that the balloon has a check valve that allows the filling to be injected but prevents it from flowing out.

Further, it is preferable that the filler is silicone.

Hereinafter, the specific configuration of the present invention will be explained in detail.

FIG. 1 shows a cross-sectional view of one embodiment of the balloon-type intraocular lens of the present invention.

A balloon-type intraocular lens (hereinafter referred to as an intraocular lens) 10 shown in FIG. 1 basically consists of a balloon 12 and a filler 14 filled in the balloon 12. The balloon 12 is preferably provided with a check valve 16. Such intraocular lens 10
It is formed from a thin membrane-like sheet, folded into a small size by rolling it as shown in FIG. By doing so, the intraocular lens 10 is formed.
It acts as a lens instead of a crystalline lens.

The balloon 12 of the intraocular lens 10 of the present invention is a hollow body molded from a light-transmitting plastic with low elasticity and a tensile modulus of 2 kgf/+nm" or more, and has a check valve 16. be.

In the present invention, light transmittance refers to visible light (wavelength 380~
780 n+++) is 60% or more.

Furthermore, the tensile modulus applied in the present invention is 2 kgf
Plastics with low elasticity of /+nm" or more indicate moldable resin compounds with low elasticity and little expansion due to expansion when external force is applied, and the elasticity at around room temperature is low. It should be distinguished from elastomers rich in elasticity in this respect.The tensile modulus may be determined according to the test method of JIS K 7113 (23±2°C).

Examples of such plastics forming the balloon 12 include polyamide, polyimide, polyester, etc., and aromatic linear polyester is a preferred example.

Among these, polyethylene terephthalate (PET) derived from an aromatic dicarboxylic acid or a derivative thereof as a main component and an aliphatic glycol as a main glycol component is particularly preferably used. PET is a semi-crystalline polymer that can be melt extruded and drawn into a variety of molded structures.

In addition, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, didecamethylene glycol, decamethylene glycol, cyclohexane dimeta Various polymers derived from aliphatic glycols having 2 to 10 carbon atoms, such as tools, are also applicable.

The balloon 12 is made of such a plastic with low elasticity,
In particular, by forming the lens with PET, it becomes difficult to form the lens with a highly elastic material such as an elastomer. It is possible to easily know that the inner lens 10 has attained a predetermined shape, and the lens is not expanded due to insufficient injection of filler or injection of more than necessary filler, and the lens can easily be formed into an accurate predetermined shape. The lens performance can be fully demonstrated. In addition, since the internal pressure after forming the intraocular lens 10 is not high, even if the balloon 12 is damaged within the eye, it will not burst or damage surrounding cells. Since it does not absorb water, problems such as denaturation of aqueous humor components do not occur.

The tensile modulus of such plastics is 2 kgf, which is important for safety and the ease with which lenses can be shaped into a given shape.
/m112 or more, preferably 10 to 2000 k
By setting gf/ZenC, the error in lens design can be kept low (
More favorable results can be obtained in terms of reducing pressure on surrounding tissues during intraocular fixation. Furthermore, the tensile modulus is increased from 100 to 1000 kgf/m.
By setting ff12, more favorable results can be obtained in the above points.

The balloon 12 of the intraocular lens 10 of the present invention is a hollow body molded from such plastic, and the thickness of the sheet forming this hollow body is preferably 50 μm or less. By setting the thickness of the sheet forming the balloon to 50 μm or less, it can be easily inserted into the eye, has appropriate elasticity and flexibility after injecting the filler 14, and has good transparency. It is possible to obtain more favorable results in terms of ensuring the following.

The thickness of the sheet forming the hollow body is approximately μW to 20 LLm, so that it can be easily folded when inserted into the eye, and the resistance when injecting the filling material 4 to restore the lens shape is More favorable results can be obtained in terms of reducing the amount of refractive index of the sheet, and by setting the value to 1 μff from 1 to 10 μm, the flexibility is increased and plastic deformation is less likely to occur under normal usage conditions, and the influence of the refractive index of the sheet is kept low. Further favorable results can be obtained in terms of ease of lens design and the like.

There is no particular limitation on the method of molding the balloon 12, and any known method such as injection molding may be used.

In the illustrated intraocular lens 1o, a check valve 16 is provided in the balloon 12 as a preferred embodiment. Check valve 1
6 allows the filling 14 to be injected into the balloon 12, but prevents the injected filling 14 from being discharged;
In particular, when the filler 14 is a non-hardening liquid, the check valve 16 preferably provided is not particularly limited (in addition to various check valves such as an umbrella type and a duck hill type, self-sealing valves such as silicone rubber etc. An elastic body with high elasticity can also be suitably applied.

The check valve 16 is preferably as small as possible and placed near the end of the balloon 12 so as not to obstruct the post-operative view.

The intraocular lens 10 of the present invention is formed by injecting a filler 14 into such a balloon 12.

As the filler 14, various kinds of liquids having optical transparency as described above or solids that harden after injection can be used. Specifically, collagen, chitin, cellulose, hyaluronic acid, chondroitin sulfate, etc. solutions of natural polymer compounds or derivatives thereof, or crosslinked gels, synthetic polymer compounds such as polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyethylene oxide, polyvinylpyrrolidone, polyurethane, polyhydroxyethyl methacrylate, silicone, etc. is preferably made small. Among them, silicone is particularly preferably applied because it has low foreign material properties with respect to living organisms, has excellent biocompatibility, and can be sterilized in an autoclave.

Hereinafter, a method of using (implanting) the intraocular lens 10 of the present invention will be described.

First, as shown in FIG. 3, an incision 20 is made in the sclera 18 and an incision 24 is made in the lens capsule 22 by a surgical method, and the crystalline lens is removed. Next, as shown in FIG. 2, the balloon 12 is rolled or folded into a small size and inserted into the crystalline lens II 22 through the incisions 20 and 24. Note that, in the present invention, "folding" includes all acts of deforming and reducing the size of the balloon 12 before injecting the filler 14, such as folding and rolling.

After inserting the balloon 12 into the lens capsule 22, the check valve 1
A catheter 26 is connected to the catheter 6, and the filler 14 is injected.

Here, the injection speed of the filler 14 into the balloon 12 is:
Balloon 1 can be set arbitrarily by the surgeon.
Destruction of the tissue due to the expansion of No. 2 can be prevented, and the time required to obtain a predetermined shape can be shortened. Also,
As described above, it is easy to determine whether the intraocular lens 10 has taken on a predetermined shape by injecting the filler 14.

After the filling material 14 has been injected, the catheter 26 is pulled out and the incision hole 20 is sutured to complete the surgery.
The intraocular lens 10 has predetermined lens characteristics and functions as a lens in place of the original crystalline lens.

Although the balloon-type intraocular lens of the present invention has been described in detail above, the present invention is not limited thereto, and various changes and improvements may be made without departing from the gist of the present invention. Of course.

<Effects of the Invention> As explained in detail above, the balloon-type intraocular lens of the present invention not only can be implanted through a small incision hole, but also does not adversely affect surrounding tissues within the eye. In addition, the lens has little deviation (and can be easily and accurately formed into a predetermined shape within the eye to exhibit sufficient lens properties, allowing the patient's visual acuity to be appropriately corrected.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of the balloon-type intraocular lens of the present invention. FIG. 2 is a schematic cross-sectional view showing a state in which the balloon of the balloon-type intraocular lens shown in FIG. 1 is folded. FIG. 3 is a schematic cross-sectional view of the eye with the crystalline lens removed. FIG. 4 is a schematic cross-sectional view showing an example in which the balloon type intraocular lens shown in FIG. 1 is implanted into the eye shown in FIG. 3. 18... Sclera, 20. 24... Incision hole, 22... Lens capsule, 26... Catheter patent patent attorney.

Claims (6)

[Claims] (1) Light transmittance and tensile modulus of 2 kgf/mm^2
A balloon-type intraocular lens comprising a balloon molded from the above plastic and a light-transmitting filler filled into the balloon. (2) The balloon-type intraocular lens according to claim 1, which can be inserted into the eye through an incision hole of 3.5 mm or less formed in the sclera by folding the balloon. (3) The balloon-type intraocular lens according to claim 1 or 2, wherein the plastic is polyethylene terephthalate. (4) The balloon-type intraocular lens according to any one of claims 1 to 3, wherein the plastic has a thickness of 50 μm or less. (5) The balloon-type intraocular lens according to any one of claims 1 to 4, wherein the balloon has a check valve that allows the filler to be injected but prevents it from flowing out. (6) Claims 1 to 5, wherein the filler is silicone.
The balloon-type intraocular lens according to any one of the above.