RU2239391C1 - Artificial eye lens and method for manufacturing artificial eye lens - Google Patents

Abstract

FIELD: medicine; medical engineering.

SUBSTANCE: method involves pouring liquid photo-hardening material in turn into two casting molds produced from optically transparent material. They are exposed to ultraviolet radiation. The not hardened material is removed and additional treatment with ultraviolet radiation is carried out. The produced artificial eye lens is enclosed into closed reservoir containing isopropyl alcohol and subjected to thermovacuum drying. Optical part of the lens is built from external and internal components one enclosed in the other.

EFFECT: improved and simplified production process; reduced risk of traumatic complications.

5 cl, 7 dwg

Description

The invention relates to medicine, and specifically to ophthalmology, and relates to a method for the manufacture of artificial eye lenses.

A known method of manufacturing artificial lenses of the eye (IHG) by high-temperature vulcanization in the injection mold of an organosilicon polymer with subsequent temperature control.

The disadvantage of this method is that the prolonged curing of almost all known polymers at high temperatures of 200-300 ° C leads not only to their crosslinking (vulcanization), but also to destruction. During the destruction of polymers, low molecular weight products are formed that can diffuse into the tissues of the eye and cause toxicology.

Another disadvantage of this method is that it allows the use of only a very narrow class of materials, namely, those with a shrinkage coefficient close to zero, in the manufacture of artificial lenses (Polymer Optical Materials of the Collected Articles. Chernogolovka, 1989, p. 199).

A known method of manufacturing an artificial lens of the eye, which consists in the fact that the injection mold is filled with liquid photocurable material, irradiated with UV light, the uncured photographic material is removed and annealed (RF patent No. 2074673).

A significant disadvantage of this invention is the presence of certain trauma associated with insufficient elasticity of the artificial lens of the eye.

A known method for the manufacture of artificial eye lenses is that liquid photocurable material is poured into the mold, irradiated with UV light, the uncured photographic material is removed and annealed, then the artificial eye lens is placed in a closed container with isopropyl alcohol at a temperature of from -20 to + 12 ° C and maintain them for 3 to 24 hours, after which they produce thermal vacuum drying at a temperature of 40 to 70 ° C for 1 to 6 hours (RF patent No. 2129846, taken as a prototype).

This method allows to produce only monofocal artificial lenses of the eye, which do not provide vision near and far at the same time.

The technical task of the proposed method is the creation of an artificial lens of the eye, providing simultaneous vision near and far with its low invasiveness, ease of implementation of the method, as well as expanding the arsenal of methods for producing artificial lenses of the eye.

The technical task according to the invention is solved by the fact that in the method of manufacturing an artificial lens of the eye, which consists in pouring a liquid photocurable material into an injection mold made of optically transparent material, irradiating with UV light, removing uncured photographic material, and additional irradiating with UV light place the obtained artificial eye lens in a closed container with isopropyl alcohol at a temperature of from -20 ° С to + 12 ° С and maintain it for no more than 24 hours, produce movable drying at a temperature of no higher than 70 ° C for no more than 6 hours, while pouring, irradiating with UV light and removing uncured photographic material is carried out in three stages using two injection molds to form the optical part, which is composite and contains the outer and inner components obtained using two different photocurable materials, while in the first stage, pouring in the first injection mold of the liquid photocurable material to form the internal component, teach with UV light, remove uncured photographic material from only one side of the internal component, at the second stage, fill using a second injection mold of liquid photocurable material to form one half of the external component, irradiate the mold with UV light and remove uncured photographic material from the other side of the internal component , at the third stage, pouring the same liquid photocurable material to form the second half of the external component is carried out, the injection molding is irradiated Orm UV light was removed and the uncured photographic material.

It is preferable that both molds used are prefabricated and differ in the diameter of the hole to form the inner and outer components.

It is preferred that an inorganic solvent, for example, isopropyl alcohol, be used to remove uncured photographic material.

The fact that the pouring of liquid photocurable material, UV irradiation, removal of uncured photographic material is carried out in three stages using two different photocurable materials, allows you to get an artificial lens of the eye, consisting of internal and external components, which allows simultaneous vision near and far with low trauma , the ease of implementation of the method, and also expands the arsenal of methods for producing artificial lenses of the eye.

The proposed method for the manufacture of artificial lenses of the eye is as follows: for the manufacture of artificial lenses of the eye, two sets of injection molds are used, each of which consists of two halves made of optically transparent material, for example quartz, and an annular gasket, the thickness of which is equal to the thickness of the supporting part of the lens. The mold halves are made in the form of cylinders with optically polished end surfaces, on the inner surfaces of which there are recesses in the central part, which, when two mold halves are connected, form the optical part of the lens (Fig. 2). The diameter of the internal component of the lens determines the first set of injection molds; the diameter of the external component of the lens determines the second set of injection molds. On the inner surface of the upper half of the second set of injection molds, a drawing was made containing sections transparent and opaque to UV light, for example, of chromium, the negative image of which corresponds to a flat image of the optical part of the lens and its supporting elements. On the inner surface of the second half of the first set of forms made a similar pattern, the negative image of which corresponds to the image only of the optical part of the lens (figure 3).

At the first stage, an annular gasket is installed on the lower half of the first form, then a photocurable material is poured into it with the formation of the upper meniscus, the upper half of the mold is applied, the centers of the two halves of the mold are combined in two coordinates in the plane and tightly compressed.

Next, the form is irradiated with UV light, for example, with a wavelength of λ = 320-380 nm, in two stages.

Initially, the light from an external source is focused in the center of the mold and then with a uniform speed not exceeding the curing speed of the composition, the radius of the illuminated area is increased to a value equal to the radius of the optical part of the lens.

The distribution of illumination along the diameter of the optical part of the lens at the initial time should be as shown in Fig.6, at the final stage of irradiation - as shown in Fig.7. Changing the illumination of the form during the irradiation is carried out using a special exposure unit, consisting of a light source (a mercury-quartz lamp of the DRT-120 brand), a diaphragm, an optical system that allows you to project the open part of the diaphragm onto the working surface of the injection mold, and a device that allows you to open the diaphragm at a given speed (not shown). The speed of expansion of the light spot is selected so that when the boundary of the optical part of the lens is reached, complete curing of the liquid material occurs.

In the second stage, the form is irradiated over the entire surface from a light source, providing uniform illumination of the entire surface of the form. The optimal exposure time is selected empirically.

After irradiation is completed, two halves of the mold are disconnected. The product remains on one of the halves of the mold with the remainder of the uncured liquid material. The product is thoroughly washed in a suitable solvent, for example isopropyl alcohol.

The second and third stage of the manufacture of the lens repeats the staging of the first stage, using the form of the second set of injection molds in turn. The product obtained in the first stage remains on the desired side of the mold of the second set due to the use of adhesive to the back of the mold.

The product obtained in the third stage, without separating it from the mold, is additionally irradiated with UV light for 3-10 minutes in vacuum at T = 40-60 ° C. Next, the lens is separated from the mold and placed in a closed container with isopropyl alcohol at a temperature of from -20 to + 12 ° C and kept for 3 to 24 hours, then thermo-vacuum drying is carried out at a temperature of from 40 to 70 ° C for from 1 to 6 hours.

Examples of specific uses of the proposed method for the manufacture of an artificial lens of the eye.

Example 1. Artificial eye lenses are made in three stages using two sets of quartz injection molds, each of which consists of two halves. The lower halves of the forms are placed horizontally so that the recesses under the optical part of the lenses are on top. On the surface place restrictive gaskets made in the form of a ring of sheet Teflon with a thickness of 150 microns. A pre-prepared oligourethane methacrylate composition (refractive index 1.4795) is introduced into the recesses of the lower halves of the injection molds using a microdoser. The upper halves of the first set of injection molds are applied to the lower ones and pressed so that the composition completely fills the entire volume between the two halves of the molds, limited by the gasket. Filling of molds is carried out at room temperature, yellow lighting, in a dust-free atmosphere. Each of the injection molds is sequentially placed under a microscope of the MBS type and at a 12-fold increase, by moving the lower half relative to the upper one, the edge of the optical part of the upper half is aligned with the edge of the optical part of the lower half of the injection mold. The combined injection mold is tightly compressed and fixed. The injection mold is transferred to an exposure unit consisting of a light source (a DRT-120 mercury-quartz lamp), a diaphragm, an optical system that allows you to project the open part of the diaphragm onto the working surface of the injection mold, and a device that allows you to open the diaphragm at a given speed. The injection mold is placed in the exposure unit so that the incident beam passes along the main optical axis of the optical part of the injection mold, and the image of the diaphragm is formed in the cavity separating the two halves of the mold. At the initial time, the diaphragm is closed. Set the opening speed of the diaphragm corresponding to an increase in the radius of the illuminated area of the optical part by 3.5 mm in 7 minutes and perform exposure. After irradiation is completed, two halves of the mold are disconnected. The product remains on one of the halves of the mold with the remainder of the uncured liquid material. The mold with the product is placed in a development unit consisting of a 200 ml development cuvette, a developer circulation pump, and a nozzle located in the cuvette lid. The mold with the product is placed in a cuvette, the developer isopropyl alcohol is poured, closed with a lid and the pump is turned on. The manifestation time is 2 minutes. During the development, the unpolymerized portion of the photocurable material is removed, which was exposed under the UV-opaque portions of the pattern made on the inner surface of the upper half of the injection mold.

The second and third stages of lens manufacturing repeat the staging of the first stage, using the forms of the second set of injection molds in turn, and oligocarbonate methacrylate as a photocurable material, the refractive index of which is 1.4795. The product obtained in the first stage remains on the desired side of the mold of the second set due to the use of adhesive to the back of the mold.

The product obtained in the third stage, without separating it from the mold, is additionally irradiated with UV light for 10 minutes in vacuum at a temperature of 60 ° C. Next, the lens is separated from the mold and placed in a closed container with isopropyl alcohol at a temperature of -20 ° C and kept for 24 hours, after which they produce thermal vacuum drying at a temperature of 70 ° C for 6 hours.

Example 2. Artificial lenses of the eye are made as in example 1, but oligocarbonate methacrylate is used as the liquid photocurable material in the first stage, and oligourethane methacrylate in the second and third stages.

The product obtained in the third stage, without separating it from the mold, is additionally irradiated with UV light for 3 minutes in vacuum at a temperature of 40 ° C. Next, the lens is separated from the mold and placed in a closed container with isopropyl alcohol at a temperature of 12 ° C and kept for 3 hours, then thermo-vacuum drying is carried out at a temperature of 40 ° C for 1 hour.

This method is made of 20 artificial eye lenses according to examples 1 and 2.

The proposed artificial lens of the eye can be made only by the proposed method.

Most patients after cataract removal and implantation of a monofocal artificial lens do not receive equally good vision for near and far. This group of patients needs additional correction: spectacle, or contact, or refractive surgery, or monovision correction, providing good vision in the distance and near.

Known artificial lens of the eye having an optical part, consisting of various cylindrical segments of different optical power (US patent No. 4795462).

Known for the artificial lens of the eye, having an optical part, consisting of horizontally oriented plates of different optical power (US patent No. 4798608).

Known artificial lens (US patent No. 5222981), which includes a base lens, two surface parts ("caps") and many fasteners to hold the "caps" on the base lens.

The above known designs of artificial lenses of the eye do not require additional correction after implantation. However, they are difficult both in manufacturing and for implantation in the eye.

Known artificial lens of the eye (US patent No. 5152788), which consists of 2 components. Each of the components has a smooth outer surface and an inner surface with a sharp edge around the periphery. The multifocal diffraction zone is located on at least one lens in a 2-component system and determines the refractive index. The lenses of the system are connected by edges by ultrasonic welding, forming a cavity adjacent to the surface of the diffraction zone. The cavity is filled with liquid contents having a refractive index different from the refractive index of the diffraction surface. The cavity, thanks to one of the lenses of the system, functions as a mechanism of active transport of fluid between the eye and the cavity of the lens.

In the given design, it is difficult to calculate the rate of active transport of fluid in the lens chamber, the mechanism of the initial replacement of air by liquid. It is difficult to predict the biological processes in the lens chamber, both in terms of changes in the refractive index and loss of transparency due to protein adsorption, and stagnation. The use of the diffraction zone leads to an increase in the area of contact with biologically active tissues, which also increases the risk of complications.

Known bifocal artificial lens of the eye (US patent No. 5217489, taken as a prototype). The lens consists of supporting elements and the optical part. The optical part has a front surface divided into optical zones and a rear surface not divided into zones. The central zone of the lens, from 1.5 to 2.0 mm in diameter, provides distance vision. The second circular zone for near vision has an inner diameter of from 1.5 to 2.0 mm and an outer diameter of from 2.8 to 3.5 mm, respectively. The second zone has a greater optical power compared to the distance for the distance of 2.0-5.0 D. The peripheral zone for distance vision extends from the outer edge of the second zone to the edge of the optics. The lens can be made of various optical materials. Three zones for the nearest and further vision can be located on the front and rear surfaces of the optical part. The shape of the surface intersected by sections is not limited.

The described design of the artificial lens of the eye provides vision for near and far away at the same time, but the lens is difficult to implant, and to provide simultaneous vision for near and far the lens has a complex structure of the front or back surface, which leads to an increase in the active area of the optical part. Moreover, a complex surface structure contacts either the iris or the posterior lens capsule, which can provoke either inflammatory phenomena or the development of secondary cataract.

The technical task is to create an artificial lens of the eye with a simple structure, less trauma, ease of implantation, providing vision near and far, as well as expanding the arsenal of artificial lenses of the eye.

The stated technical problem is solved in that in the artificial lens of the eye, containing the optical part and supporting elements, according to the invention, the optical part is made integral and contains internal and external components located one inside the other, their refractive indices differ by at least 0.03, each of the components contains at least two optical surfaces, while each of the optical surfaces has at least one spherical element, the optical axis of which coincides with the center the optical axis of the artificial lens of the eye, and / or one optical element formed by a surface of revolution of at least second order.

It is preferable that the support elements and the outer component can be made of one optical transparent material (as a monolith), or of different ones.

Such a model of an artificial lens of the eye is the simplest structurally, since the external component has smooth external surfaces. This, in turn, does not change the normal course of the operation. The model is simple for implantation; it can be used in surgery of small incisions. Structurally, the model is simple to manufacture and the least traumatic. Due to the combination of materials with a different refractive index, the artificial lens of the eye allows you to get the best visual functions: near, far, vision correction, aberration correction. The structure of the artificial lens of the eye is closest to the natural lens, which makes vision correction the most physiological.

In the proposed artificial lens of the eye, containing the optical part and the supporting elements, the optical part is made integral and contains internal and external components located one inside the other. The diameter of the internal component (from 1.5 to 3.0 mm) is less than the diameter of the external component (from 5.25 to 6.0 mm). The inner and outer components can be made of various groups of transparent optical materials, the refractive indices of which differ by no less than 0.03. The support elements and the external component can be made of one optically transparent material (such as a monolith), or from various materials. Each of the components contains at least two optical surfaces, and each of the optical surfaces has at least one spherical element, the optical axis of which coincides with the central optical axis of the artificial lens of the eye, and / or one optical element formed a rotation surface of at least second order.

The invention is illustrated by drawings.

Figure 1 shows the artificial lens of the eye, in the context of the front and side, where 1 is the internal component of the optical part, 2 is the external component of the optical part, 3 - support elements.

Figure 2 shows a General view of the mold in the assembled state, where 4 is the lower half of the mold, 5 is the upper half of the mold, 6 is an annular gasket.

Figure 3 presents a top view of the inner surface of the lower half of the form without the upper half, where 7 is a transparent section corresponding to the optical part of the lens.

Figure 4 presents the lower half of the injection mold after pouring the composition, where 8 is the flooded photocurable composition.

Figure 5 shows a General view of the injection mold in the assembled state with the filled composition.

Figure 6 shows the distribution of light intensity Eo at the initial moment of exposure, where r _o is the radius of the optical part.

In Fig.7 - the distribution of light intensity Eo at a time corresponding to a fully illuminated optical part.

The injection mold of each set consists of the lower 1 and upper 2 halves, 3 - an annular gasket.

Examples of specific uses of the proposed artificial lens of the eye.

The proposed method was made 20 of the proposed artificial lenses of the eye. The implantation of manufactured artificial eye lenses was achieved with the achievement of high visual functions.

Claims (5)

1. A method of manufacturing an artificial lens of the eye, which consists in pouring a liquid photocurable material into an injection mold made of optically transparent material, irradiating the injection mold with UV light, removing uncured photographic material, producing additional irradiation with UV light, and placing the resulting artificial eye lens in a closed container with isopropyl alcohol at a temperature of from -20 to + 12 ° C and maintain it for no more than 24 hours, perform thermal vacuum drying at a temperature of no higher than 70 ° C for no more 6 hours, characterized in that the pouring, irradiation with UV light and removal of uncured photographic material is carried out in three stages using two injection molds to form the optical part, which is composite and contains the outer and inner components obtained using two different photocurable materials, at the first stage, the liquid photocurable material is poured into the first injection mold to form the internal component, the mold is irradiated with UV light, and the uncured the photographic material is only on one side of the inner component, at the second stage, pouring using the second injection mold of the liquid photocurable material is carried out to form one half of the outer component, the mold is irradiated with UV light and the uncured photographic material is removed on the other side of the inner component, at the third stage, this is filled the same liquid photocurable material to form the second half of the external component, irradiate the mold with UV light and remove the uncured photographic material. 2. A method of manufacturing an artificial eye lens according to claim 1, characterized in that the injection molds used are prefabricated and differ in the diameter of the hole for forming the outer and inner components. 3. A method of manufacturing an artificial eye lens according to claim 1, characterized in that an organic solvent in the form of isopropyl alcohol is used to remove uncured photographic material. 4. An artificial lens of the eye, containing the optical part and support elements, characterized in that the optical part is made integral and contains internal and external components located one inside the other, and their refractive indices differ by at least 0.03, each of the components contains at least two optical surfaces, each of the optical surfaces having at least one spherical element, the optical axis of which coincides with the central optical axis of the artificial crunch the face of the eye, and / or one optical element formed by a surface of revolution of at least second order. 5. The artificial eye lens according to claim 4, characterized in that the supporting elements and the external component are made of one optically transparent material in the form of a monolith or from different optically transparent materials.

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