RU125841U1 - Intraocular lens - Google Patents

Abstract

1. An intraocular lens with variable optical power, having a front optical element with almost constant optical power in the direction of light, which is made of a viscoelastic biocompatible polymer and has a spherical front surface and a flat rear surface, a rear optical element with a variable optical power in the form of a shell, which made of elastic biocompatible polymer, fits snugly to the front optical element, has a spherical back surface and is filled with liquid with an indicator m of refraction of more than 1.336, at least two haptic elements spaced by almost equal angular distances, in which the proximal parts are connected to the front optical element and the distal parts, in the working position, are in contact with the equatorial zone of the capsule, and the ring-shaped clip is made of a biocompatible polymer, which contacts on the one hand with the rear optical element and on the other hand, in the working position, with the vitreous body of the eye through the back wall of the capsule, characterized in that it is equipped with a nym biocompatible viscoelastic polymer additional overhead clamp anterior optic element relative irido-ciliary solid angle, and an annular clamp is also made of a biocompatible viscoelastic polymer and is docked in the operating position with the distal portions of said haptics elementov.2. The intraocular lens according to claim 1, characterized in that the additional patch retainer of the front optical element has a locking part in the form of two half rings, the common geometric axis of which is practical

Description

Technical field

The invention relates to the design of intraocular lenses with variable optical power, which are usually implanted in cataract patients after removal of (usually by phacoemulsification) predominantly clouded lenses.

State of the art

It should be noted that hereinafter, the term "intraocular lens" (abbreviated IOL), means any transparent product that has at least one optical element replacing the natural lens and auxiliary units or parts that, after implantation of the IOL, ensure its fixation in the eye the patient and the interaction of the parts of the IOL with each other and with the anatomical elements of the prosthetic eye.

It is well known that the first IOLs were made from inelastic organic glass (i.e., high molecular weight polymethyl methacrylate). Their implantation was associated with serious injury to the eyes of patients, and then accommodation was out of the question.

Modern IOLs are made from flexible polymers. They can be twisted and placed in hollow injectors of very small (less than 3 mm) diameter. This significantly reduced surgical trauma during IOL implantation.

At the same time, the possibility of serial production of IOLs appeared, in particular for the correction of myopia or hyperopia. Indeed, there are many sites on the Internet where different firms, among which the most famous manufacturers are Alcon and Bausch & Lomb and the trading company Rumex International *, offer a variety of sets (in particular, multifocal) IOLs with different (but almost constant ) optical power.

However, patients with significant myopia or farsightedness are relatively few among cataract patients, while automatic regulation of the optical power of the IOL depending on the specific conditions of visual observation is necessary for everyone.

For this, it is necessary to have an IOL capable of changing the optical power depending on the distance of the prosthetic person to the observed objects.

From US 4,373,218 (1980), a predominantly biconvex (less often plano-convex or other) IOL is known, designed to be installed in the posterior chamber of the eye along the inner perimeter of the ciliary body instead of a distant natural lens.

It has an elastic shell filled with a liquid crystal fluid of a biocompatible polymer (polyethylene, polypropylene or silicone), which is equipped with haptic (i.e. supporting) elements, in particular small radial spikes, around the perimeter of the ciliary body and has a flap valve with an inlet tube that extends through the sclera to the limbus (approximately 2.5 mm). After fluid is introduced into the membrane, this tube is usually closed by the conjunctiva. For automatic regulation of the optical power in such an IOL implanted in the eye is provided: means based on the eye position sensor, designed to form a proportional required accommodation of the input electrical signal in accordance with the compression or relaxation of the ciliary body,

a microprocessor electrically connected to a liquid crystal fluid inside the elastic shell and means for generating a proportional desired accommodation of the input electrical signal and capable of generating an output control signal,

thin electrodes for regulating the optical density (and, accordingly, refraction) of the liquid crystal fluid, which are connected to the control output of the microprocessor, and

source of electrical power for said parts.

According to the inventive concept, the known IOL should automatically change the optical power depending on the distance of the prosthetized person to the observed objects.

However, such eye robotization is very unreliable and has practically no chance of implementation. Therefore, it is desirable to create simpler to manufacture and reliable IOL, in particular using two optical parts, at least one of which can change its shape and optical power.

So, in 1989 (see SU 18010052), an IOL was proposed having:

an optical element, consisting of a central (refractive) chamber sequentially located along the path of the light, which is bounded in front by an elastic shell (membrane) and is filled with liquid, and a collective lens that fits snugly against the back wall of the central chamber,

a reservoir with a supply of liquid located on the side of the central chamber, hydraulically connected to it through an opening and bounded at the back by an elastic shell, which is equipped with a permanent magnet,

haptic elements for fixing the IOL relative to the remnants of the capsule of the distant natural lens, namely: an elastic half-loop on one side and the specified reservoir on the other side of the central chamber.

The fluid filling the central chamber and reservoir should have a refractive index greater than that of intraocular fluid (i.e., greater than 1.336). In addition, the known IOL has a permanent magnet external to the eye (in particular, implanted into the lower edge of the orbit) to regulate the ratio of the volumes of the central chamber and reservoir filled with liquid and, accordingly, the optical power.

It is clear that the use of intraocular and extraocular magnetic implants technically simplifies the regulation of optical power in comparison with the microprocessor-based system that is completely integrated into the eye. However, the implantation of magnets (especially in the eyes) is undesirable from the point of view of injuring the patient during surgery and the possibility of damage to the eye under the influence of a powerful external magnetic field. Therefore, such a significantly simplified version of the IOL is still practically not used.

A known attempt to solve the problem of accommodation of IOLs using two interconnected in the working position suitable haptic elements of optical elements sequentially located in the direction of the light (RU 2128026 C1). One of them is an artificial biconvex analog lens of the removed lens and is implanted in the eye, and the second (external) spherical cylindrical optical element is interchangeable and serves to eliminate postoperative astigmatism and / or correction of age-related presbyopia.

Installation and replacement of an external optical element is possible only in a specialized medical institution. Moreover, the optical power of the described IOL cannot be effectively changed according to the accommodation reflex depending on the distance of the prosthetic person to the observed objects.

The first practically acceptable approach to mechanical accommodation of the IOL for current visual observation conditions is known from the description and drawings of the invention for UA 68731 A. According to this invention, the IOL intended for installation in a capsule has:

a sealed chamber made of a biocompatible polymer which is filled with a fluid medium with a refractive index of more than 1,336,

a biconvex lens-prosthesis of the lens, which is located in a sealed chamber between its front wall and the rear o-ring and is able to change its shape and position relative to the camera in response to changes in intraocular pressure, and

at least two haptic elements spaced by almost equal angular distances, in which the internal parts are fixed relative to the peripheral part of the biconvex lens, and the external parts in the working position are fixed relative to the ciliary body of the eye in the equatorial plane of the lens capsule.

Such an IOL, in principle, is able to automatically change the optical power of the lens depending on the actual need for accommodation. Indeed, tension or relaxation of the ciliary body in response to the accommodation reflex changes the vitreous pressure on the IOL. Accordingly, the internal parts of the haptic elements bend, moving the lens forward with a simultaneous decrease in the radius of curvature of its front wall and an increase in refraction, or vice versa.

However, the possibility of accommodation is significantly limited by the mechanical properties of the polymer film from which the front wall of the lens is made, and therefore it is hardware-programmed even during the manufacture of the IOL.

Closest to the technical nature of the proposed, and therefore adopted as a prototype IOL with variable optical power is known from UA 86709. It has in the direction of the world:

a front optical element with an almost constant optical power, which is made of a viscoelastic biocompatible polymer and has a spherical front part and a spherical or flat rear part with an annular protrusion,

a rear optical element with a variable optical power in the form of a shell, which is made of an elastic biocompatible polymer, fits snugly to the front optical element, is filled with a liquid with a refractive index of more than 1.336 and has a spherical rear surface and a diameter larger than the diameter of the specified annular protrusion in the front optical element,

a clamp in the form of a rigid ring of biocompatible polymer, which in the working position is in contact on the one hand with the rear optical element and on the other hand with the vitreous body of the eye through the back wall of the capsule, and

at least two haptic elements spaced by almost equal angular distances, in which the proximal parts are connected (in particular, made integrally) with the shell of the anterior optical element, and the distal parts - in the working position - are brought into contact with the equatorial area of the lens capsule.

The specified clip improves the accommodation properties of the known IOL only partially. Indeed, the “haptic elements - front optical element” complex is capable of displacing under the action of the clamp as a whole and thereby reduce the contribution of the deformed rear optical element to the regulation of the optical power of the IOL. In addition, rigid clamping significantly complicates the implantation of IOLs, returning ophthalmic surgeons to traumatic and lengthy operations using rigid artificial lenses.

Utility Model Essence

The utility model is based on the task of adding design and, in particular, improving the relative positioning of parts to create a more convenient implantation and more efficient IOL operation.

This problem is solved in that the IOL with variable optical power, having

a front optical element with an almost constant optical power, which is made of a viscoelastic biocompatible polymer and has a spherical front surface and a flat rear surface,

a back optical element with a variable optical power in the form of a shell, which is made of an elastic biocompatible polymer, fits snugly to the front optical element, has a spherical back surface and is filled with a liquid with a refractive index of more than 1.336,

at least two haptic elements spaced by almost equal angular distances, in which the proximal parts are connected to the front optical element and the distal parts in the working position are in contact with the equatorial zone of the capsule, and

an annular clip made of a biocompatible polymer, which contacts on the one hand with the rear optical element and on the other hand, in the working position, with the vitreous body of the eye through the back wall of the capsule,

according to the inventive concept, it is equipped with an additional patch retainer of the front optical element relative to the iridociliary solid angle made of a viscoelastic biocompatible polymer, and the annular clip is also made of a viscoelastic biocompatible polymer and docked in the working position with the distal parts of these haptic elements.

This design allows you to twist most of the proposed IOL and implant it through a suitable hollow injector, followed by the introduction of also twisted additional patch clamp through paracentesis. At the same time, these relationships between the parts determine the stabilization of the position of the front optical element in the prosthetic eye regardless of the position of the ring-shaped clip and, accordingly, provide full-fledged automatic control of the optical power due to deformations of the rear optical element. Thus, the proposed IOL in comparison with the prototype is more convenient in implantation and more efficient in operation.

The first additional difference is that the additional overhead retainer of the front optical element has a locking part in the form of two half rings, the common geometric axis of which practically coincides with the optical axis of the optical elements, and an oval-shaped in-plane haptic element, in which these half rings are attached to the middle part , and the lateral parts are pinched in the working position in the iridociliary solid corner. This ensures the self-centering of such a retainer relative to the optical axis of the prosthetic eye after completion of the IOL implantation.

The second, additional to the first difference, is that the indicated oval-shaped haptic element has an incision on one side, which gives it additional flexibility and facilitates its installation in the iridociliary body angle.

Brief Description of the Drawings

Further, the essence of the utility model is illustrated by a detailed description of the design and features of the IOL with links to schematic drawings, which are shown in:

figure 1 is a General view of the implanted IOL with a fragment of the prosthetic eye (longitudinal section of the plane of symmetry);

figure 2 is a plan view of an additional patch retainer of the front optical element (optimal option);

figure 3 is a profile of an additional overhead retainer of the front optical element (optimal option);

figures 4 and 5 are a longitudinal section of the optical elements and the ring-shaped clip by the plane of symmetry, respectively, in the initial state and in the state of deformation of the rear optical element.

Detailed description of utility model

The proposed IOL (see figure 1, where, for convenience, some anatomical details of the prosthetic eye are also indicated) has:

front-facing optical element 1 with an almost constant optical power, which is made of a viscoelastic biocompatible polymer and has a spherical front surface and a flat rear surface,

a rear optical element 2 with a variable optical power in the form of a shell, which is made of an elastic biocompatible polymer, fits snugly against the flat rear surface of the front optical element 1, has a spherical rear surface and is filled with a liquid with a refractive index of more than 1.336,

at least two main haptic elements 3 spaced apart by almost equal angular distances, in which the proximal parts are connected to the anterior optical element 1 and the distal parts, in the working position, are brought into contact with the equatorial area of the remainder of the lens capsule 4,

the annular clip 5, which is made of a viscoelastic biocompatible polymer, contacts on the one hand with the rear optical element 2 and on the other hand, in the working position, with the vitreous body 6 of the eye through the back wall of the remainder of the capsule 4 and which is joined to the distal parts of the main haptic elements 3 ,

additional patch clamp 7 of the front optical element 1 relative to the solid angle between the iris (iris) 8 and the ciliary body 9 (which is referred to above as the "iridociliary solid angle").

The latch 7 is made of a suitable viscoelastic biocompatible polymer and has (see FIG. 2) a locking part in the form of two semi-rings not specifically designated, the common geometric axis of which practically coincides with the optical axis of the optical elements 1 and 2, and also not specially marked oval-shaped own haptic element, to the middle part of which the indicated half rings are attached and the lateral parts of which are pinched in the working position in the iridociliary body angle, as can be seen in Fig. 1.

It is advisable that the oval-like haptic element has a cut on one side, which gives it flexibility and facilitates installation in an iridociliary flesh corner. Further, from the anatomy of the eye, it is known that the gap between the iridium 8 and the ciliary body 9 can open up to an angle of 15 °. Therefore, it is desirable that the lateral parts of the oval-like haptic element of the retainer 7 be bent against the light path relative to the rear flat surface of the front optical element 1 by an angle “a” from 5 to 15 °, and mainly from 5 to 7 ° (see figure 3). This allows you to adjust in a wide range the optical power of the rear optical element 2 even when its axial size does not exceed the axial size of the front optical element 1.

It is also desirable that the liquid used to fill the shell of the rear optical element 2 has a refractive index in the range from 1.4 to 1.5 and even higher. This can be achieved using silicone oils with different degrees of polymerization.

The term "almost constant optical power" in the characteristic of the optical element 1 means only that its value is unchanged during operation of the implanted IOL. However, it can be individually selected taking into account the initial optical parameters for specific patients and recorded during the manufacture of IOLs.

The shape and number of the main haptic elements 3 can be selected over a wide range from a variety of generally accepted, and therefore not shown in the drawings, samples. So, these elements 3 can have a central ring, which on the periphery is equipped with two pairs of "hare ears" spaced apart by almost equal angular distances, or a pair of sickle-shaped protrusions that are twisted in one direction clockwise (or against it), or three radial ear-like protrusions, etc.

The proposed IOL is implanted in the eye in this way.

First, tunnel paracentesis and also a tunnel incision are performed in the cornea with the injection of anesthetics and pupil dilation into the anterior chamber of the eye, the anterior wall of the lens capsule is stained with a biocompatible dye, the anterior chamber of the capsule is filled with biocompatible viscoelastic, and central capsulorhexis with a diameter of 5 to 7 mm is removed from the front with removal excised parts of the capsule and destroy the natural crystalline lens by ultrasound with aspiration of the formed mass. After washing out the residues of viscoelastic from the remaining part of the capsule after capsulorexis, the proposed IOL is established in two stages.

At the first stage, through the capsulorexis, deeper into the capsule, through the hollow injector not shown in the drawings, a bundled kit is introduced that includes the main haptic elements 3, the front optical element 1, the rear optical element 2 and the ring-shaped clip 5. After the deployment of these parts, the optical elements 1 and 2 are located in the central part of the capsule on the optical axis of the eye, the distal parts of the main haptic elements 3 are supported from the inside on the equatorial zone of the capsule 4, and the annular clip 5 is included in the proper The contact on the one hand with the rear optical element 2, and on the other hand through the rear solid wall of the capsule 4 with the vitreous 6 of the eye.

At the second stage, a folded additional retainer 7 is inserted through the tunnel paracentesis with micro-tweezers, which is deployed, and its half-rings lock the front optical element 1 in front of the rest of the front wall of the capsule 4, and the distal parts of the oval-shaped haptic element are pinched in the iridociliary body corner.

After implantation, automatic mechanical accommodation occurs as follows.

When the prosthetic eye is relaxed, parts of the IOL occupy the position shown in FIG. 4. If you need to clearly see closely located objects, an accommodation reflex occurs, which is realized by narrowing the ring of the ciliary body 9 and a corresponding increase in pressure in the vitreous body 6 of the prosthetic eye. This pressure causes the clip 5 to move against the direction of the light and deform the shell of the rear optical element 2 in the direction of decreasing the radius of its curvature (see Fig. 5). Accordingly, the optical power of the IOL increases. When you transfer your gaze to objects remote from the eye, the process occurs in the reverse order.

Industrial applicability

The proposed IOL can be a mass-produced product using well-known viscoelastic and elastic biocompatible polymer materials, for example: flexible hydrophilic (or sometimes hydrophobic) polymethyl methacrylate, silicone, copolymer of 2-phenylethyl acrylate and 2-phenylethyl methacrylate, etc.

Claims (3)

1. An intraocular lens with variable optical power, having a front optical element with almost constant optical power in the direction of light, which is made of a viscoelastic biocompatible polymer and has a spherical front surface and a flat rear surface, a rear optical element with a variable optical power in the form of a shell, which made of an elastic biocompatible polymer, fits snugly to the front optical element, has a spherical back surface and is filled with liquid with an indicator m of refraction of more than 1.336, at least two haptic elements spaced by almost equal angular distances, in which the proximal parts are connected to the front optical element and the distal parts, in the working position, are in contact with the equatorial zone of the capsule, and the ring-shaped clip is made of a biocompatible polymer, which contacts on the one hand with the rear optical element and on the other hand, in the working position, with the vitreous body of the eye through the back wall of the capsule, characterized in that it is equipped with a nym biocompatible viscoelastic polymer additional overhead clamp anterior optic element relative irido-ciliary solid angle, and an annular clamp is also made of a biocompatible viscoelastic polymer and is docked in the operating position with the distal portions of said haptics. 2. The intraocular lens according to claim 1, characterized in that the additional patch retainer of the front optical element has a locking part in the form of two half rings, the common geometric axis of which practically coincides with the optical axis of the optical elements, and an oval-shaped inherent planar haptic element, in which the middle part is attached to these half rings, and the side parts are pinched in the working position in the iridociliary solid corner. 3. The intraocular lens according to claim 2, characterized in that the indicated oval-shaped haptic element has an incision on one side.

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