EP3946154A1

EP3946154A1 - Cornea implant

Info

Publication number: EP3946154A1
Application number: EP20720903.2A
Authority: EP
Inventors: Albert Daxer
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-04-01
Filing date: 2020-03-30
Publication date: 2022-02-09
Also published as: WO2020201221A1; US20220202562A1

Abstract

The invention relates to an annular implant having shape memory for implantation into the cornea of the eye, wherein, in an initial state, the implant spans an implant plane, and wherein the implant can be transitioned from an initial state into an intermediate state by imposing a compressive force (F) in the implant plane (8), in which the lateral dimensions of the implant, measured in the direction of force, are smaller than in the initial state, wherein according to the invention the alignment of an implant cross-section (1) in the intermediate state is twisted at least in a twistable longitudinal portion of the implant about an angle (α) relative to the initial state.

Description

CORNEAL IMPLANT

FIELD OF THE INVENTION

The present application relates to an annular implant

Shape memory for implantation in the cornea of the eye, the implant spanning an implant plane in an initial state, and the implant being produced by a compression force in the implant plane

The initial state can be converted into an intermediate state in which the lateral dimensions of the implant, measured in the direction of force, are smaller than in the

Initial state.

STATE OF THE ART

About 70% of the refractive power of the eye depends on the central curvature of the anterior corneal surface. Hence, most of the treatments are based on

Ametropia on the change in the central radius of curvature. For example, if you want to reduce the refractive power of a myopic eye, e.g. To enable vision without visual aid, the central radius of curvature of the anterior corneal surface must be increased and its central curvature thus reduced. To achieve this, tissue can be removed from the cornea, for example with an excimer laser, in the center of the cornea rather than further peripherally. The same effect can be achieved by creating a volume in the periphery in the form of a ring-shaped implant in the cornea. The corneal tissue in the periphery, where the implant is just inserted, has to take a "detour" around the thickness of the implant, which leads to a central shortening of the arc length and thus to a flattening of the anterior corneal surface. In any case, however, the weakening of the

Cornea pose a problem by treating the cornea. In the case of laser ablation, it is simply the loss of tissue and in the special special case of LASIK, where a corneal flap must also be prepared, including this one that weakens the cornea. In any case, the thickness of the cornea and the number of diopters that must be removed set limits to the extent of the laser ablation (ablation depth). In the case of corneal implants in the form of ring segments

(incomplete ring) a radial incision must be made, which weakens the cornea. Because of the cut perpendicular to the surface, this would gape. It is therefore necessary to close this radial incision with a seam, which increases the comfort, predictability and safety of the procedure

impaired. Ring segments are placed in a circular tunnel so that they are not in biomechanical equilibrium with the corneal tissue. In addition, the ring segments have ends that can locally cause high pressure on the tissue. For all these reasons, ring segments with partly afflicted with considerable postoperative complications. In order to solve these problems, US Pat. No. 8092526 B2 describes an annular implant (full ring) extended over an entire ring circumference of 360 °, which, in contrast to

segmented implants (ring segments) are not placed in a circular tunnel, but in a corneal pocket. The access to the corneal pocket through which the full ring is inserted is lamellar and in principle biomechanically neutral if it does not exceed a certain extent of approx. 5 - 6 mm. Ideally, the access should be as narrow as possible so as not to affect the biomechanics of the cornea. These biomechanical basics are in DaxerA.

Biomechanics of Cornea! Ring Implants. Cornea 2015; 34: 1493-1498 dealt with.

Since the material of the ring implants should be as stiff as possible in order to stabilize the desired corneal geometry, there is the problem that the full ring can break if the compression is too strong. The full ring described in US Pat. No. 8092526 B2 is characterized by a shape memory, according to which its diameter can be compressed to a certain extent in order to be able to introduce it into the corneal pocket through the narrowest possible access, where it then assumes the original circular shape again to fulfill its function. According to US Pat. No. 8,092,526 B2, the risk of breakage is reduced by the fact that the implant is designed in such a way that that part of the ring which is located at 90 ° to the compression force is deflected out of the ring plane when it is compressed, thereby causing another

Degree of freedom against the risk of breakage can be gained. The

Compression force partially converted into elastic deformation energy, which is stored in the deflected part of the ring 90 ° to the direction of compression force. The deflection of this ring part, which is orthogonal to the direction of force, results in a saddle-shaped geometry of the ring instead of an oval one, which requires a certain skill on the part of the surgeon during implantation, since the implant does not simply pass through the opening in the cornea can be pushed, but along a curved curve that must approximately correspond to the now curved shape of the deformed ring plane. It would be desirable if the implant could be compressed without the oval shape being so greatly modified into a steep saddle and without the rigid implant breaking during the compression. It would also be desirable to be able to compress the saddle shape even further than is possible with the invention of US Pat. No. 8092526 B2.

OBJECT OF THE INVENTION

It is the object of the invention to overcome these problems of the prior art and to provide an improved corneal implant that has a

Implantation in the cornea through a narrow wound opening is made possible without the implant breaking and a permanently safe application to the eye

Refractive power correction allowed.

DISCLOSURE OF THE INVENTION

The task is performed by a ring-shaped implant with shape memory

Implantation in the cornea of the eye is detached, the implant in one

Initial state spans an implant plane, and wherein the implant by impressing a compression force in the implant plane of one

Initial state, the invention providing that the alignment of an implant cross-section in the intermediate state is rotated at least in a rotatable longitudinal section of the implant by an angle with respect to the initial state.

In principle, the rotatable longitudinal section of the implant can extend along the entire circumferential length of 360 ° of the annular implant, but at least in sections over preferably at least 5 °, better at least 10 ° and ideally at least 15 °. Several twistable

Longitudinal sections thus each also extend at least over 5 °, better at least over 10 ° and ideally at least over 15 ° along the circumference of 360 ° of the implant. A rotatable or rotatable longitudinal section can also preferably lie in the area of the point of application of the compression force. It would be conceivable here for the implant to have a corresponding marking which indicates where the compression force is to act. At least one other longitudinal section would then not be designed to be rotatable.

The implant according to the invention can in principle be made of any material as long as it fulfills the properties according to the invention and is suitable and approved as an implant material for permanent implantation in a human body. So it can e.g. made of metal (e.g. titanium, etc.) or

Plastic (e.g. PMMA) or biological materials (e.g. collagen). The material can be transparent or opaque. It can be any color. It is preferably made of transparent plastic or in a blue, brown or green color so that it cannot be identified from the outside as a foreign body in the eye and / or the optical (not the anatomical) entrance pupil for the purpose of reducing imaging errors of higher order (e.g. spherical aberration, coma, etc.). The material should be as stiff as possible in order to enable the refractive power correction to be permanently stable, as the implant can impress a certain basic shape (curvature) on the cornea. Therefore, it should preferably have a modulus of elasticity of at least 1000 MPa, more preferably at least 2000 MPa and ideally over 3000 MPa. If it is designed as a thermoplastic, the water absorption should not exceed 5%, better 2%, and the water content should therefore be below 2% if possible. A long-term use temperature of at least 50 ° C, better 60 ° C and ideally at least 70 ° C would make sense. Often materials with such properties have only a low elongation at break (elongation at break) i.e. of just a few percent.

In principle, the implant can also have any suitable shape. Nevertheless, an essentially ring-shaped implant is particularly advantageous. The annular implant can be either closed or open, i. when

continuous ring or as an interrupted ring. The implant plane according to the invention is considered to be that plane which is delimited either by an outer edge or an inner edge of the implant. The (convex) boundary curved away from the implant represents the outer edge. In other words, in the case of an essentially ring-shaped implant, i.e. an implant with a central opening, the outer edge of the implant is the circumferential line that starts from a circle center (e.g.

The center of the implant 9 ^' in FIG. 6) is furthest away from this center, while the inner edge is the one

The circumferential line of the implant is, seen from a circle center (for example center of the implant 9 ^' ), is located closest to this center.

The implant according to the invention can be in several states, namely in an initial state, an intermediate state and one

Final state.

The initial state is that state in which the implant is before it is converted into the state in which it can be implanted by the action of a compression force. This means that in the initial state the implant normally has larger lateral dimensions than during the implantation process. Usually the lateral dimension is im

The initial state should not be larger than 10 mm.

The intermediate state is the state in which the implant from the

The initial state can be transferred by the action of a trigger and in which it can be implanted. This is done, for example, by creating a

Compression force on one or more sections of the implant, thereby reducing the lateral dimensions of the implant. It is advantageous if a lateral dimension of the implant in the intermediate state is not greater than 6 mm.

After implantation in the cornea, the implant can be converted into a final state. The final state is the state in which the implant remains after implantation in the cornea. The final state preferably corresponds essentially to the initial state of the implant. However, it is it cannot be ruled out that the final state is also a state (a different geometry) of the implant that deviates from the initial state.

An implant cross-section (hereinafter also referred to as cross-sectional area) is a cut surface of the implant (hereinafter also referred to as the implant body) which lies in a plane that is parallel to the axis of symmetry (hereinafter also referred to as the ring axis or axis of rotation or axis of rotation) of the implant, in particular through which runs or parallel to the axis of symmetry.

The implant plane is perpendicular to the at least in the initial state

Axis of symmetry of the implant.

The implant cross-section of the implant can be any, e.g. circular, oval, polygonal with or without rounded edges, convex on one side and straight or concave on the other, etc. The implant can be bent as desired along a circumferential axis (also referred to as an axis, center line, central axis, body axis or longitudinal axis) of the implant. In the initial state, however, this body axis preferably follows a constant curvature around an axis of symmetry (also referred to as the axis of rotation) with an arc length of 360 °. In the case of an implant with a circular shape, the circumferential axis would be a circle and the implant body would be a ring. If the implant is also a torus, the circumferential axis would form the center of all implant cross-sections, which would then be circles.

The implant can have a variable or homogeneous implant cross section along this circumferential axis. A homogeneous cross section means that the implant cross section is the same at any point, while a variable cross section means that the cross section differs in different areas of the implant. In the case of a homogeneous implant cross-section, both the cross-sectional shape and the orientation of the implant cross-section are important

Implant plane and the size of the cross-sectional area along the circumference are the same. The implant can be geometrically complete by extending over 360 °

Arc length extends. The implant can be mechanically incomplete or complete. A mechanically complete implant has no ends and is designed as a completely closed ring. A mechanically incomplete implant is geometrically designed over an arc length of 360 °, but has a discontinuity, i.e. a mechanical interruption, and thus ends. These ends can have any geometry. Ideally, the ends overlap.

Implants with shape memory are already known in the prior art, which are mostly temporary due to the transition to the intermediate state

Allow reduction of the lateral dimensions of the implant. Nevertheless, this reduction in the lateral dimensions is often accompanied by an increased risk of the implants breaking, since the materials of the implants of the prior art cannot withstand the forces acting on them.

According to the invention, the object is achieved in that the alignment of an implant cross-section in the intermediate state is rotated at least in sections by an angle α with respect to the initial state. The rotation of the

Implant cross-section is, for example, by the action of a

Compression force on the implant reached. This rotation has the effect that the lateral dimensions of the implant are reduced even further compared to pure compression, as a result of which the implant can be implanted into the cornea through smaller openings.

In order to be able to use the above-mentioned implant materials for the present invention, it is necessary to prevent these materials from breaking when they are compressed. When compressing the materials mentioned, if the compression is too strong, fractures occur due to material fatigue or a lack of (pseudo) elasticity in the stressed implant areas. This results on the one hand from the compression of the material in the longitudinal section that is 90 ° to the direction of the force, inside the implant or in the area of the inner edge of the implant and, on the other hand, from the tensile forces in the longitudinal section that is 90 ° to the direction the force is at which Act on the outside, in particular in the area of the outer edge of the implant. In order to prevent the implant according to the invention from breaking, the present invention achieves, for example, a rotation of the implant cross-section in a longitudinal section area along the circumference, which is preferably located at the point of force action, by the acting compression force. This enables the implant to be subjected to a greater force without breaking than when the force is applied without rotating the

Implant cross section in this rotatable longitudinal section.

In order to be suitable as a material for an implant according to the invention, it must be a material with a specific shape memory. Such materials are already well known in the prior art. At least that

section-wise rotation of the implant body along or around a

The circumferential axis in the intermediate state, triggered by an external signal, such as the action of a compression force, is achieved by the

A shape memory is impressed at least in sections on the implant body, preferably during manufacture, which ensures that when a

Compression force at least in a certain longitudinal section of the implant the desired rotation of the implant body, preferably by one

Circumferential axis takes place.

A shape memory can be impressed by mechanical, thermal, electrical or some other physical or chemical treatment of the material or the implant, preferably, but not necessarily, during manufacture. In principle, the implant can be made of any material, including plastic, metal, semiconductors, insulators, ceramics, biological substances, etc., that enables such a treatment. For example, in the case of a polymeric plastic, the alignment or arrangement of the polymer molecules can be carried out in such a way that an externally applied

Compression force leads to a force distribution in the interior of the implant body, from which the desired rotation of the implant body results. For example, the arrangement or alignment or size distribution of the polymer molecules along the circumference or within the implant cross-section can vary at least in sections along the circumference. For example the alignment of the polymer molecules can be carried out at least in sections parallel to or circularly around a circumferential axis. Furthermore, by varying the material density along the circumference or over the

Cross-section the desired twist can be achieved. Materials that are e.g. through a second order phase transition (martensitic phase transition) a certain shape through thermal or other physical treatments using a compression force in the sense of a

Allow shape memory material to be impressed and in which, in the application case, the rotation is triggered by applying a corresponding compression force, is conceivable.

It is therefore necessary that the materials used to position the

implant according to the invention can be used, can be present at least in two phases, whereby the shape memory according to the invention is provided. The conversion from one phase to the other is triggered by an external trigger, such as an acting force or

Temperature. The crystal structure of the molecules of the material used for the implant can exist in two phases and be built up differently in these phases, i.e. the molecules in one phase have a different arrangement, orientation and / or size distribution than in the other phase. For the

According to the invention, both materials with thermal and mechanical shape memory can be used.

It can also be provided that a rotatable longitudinal section extends along the circumference of the implant outside the point of application of the

Compression force is located.

In order to be able to reduce the lateral dimensions of the implant in the intermediate state particularly effectively, in one embodiment of the invention

provided that the implant has two mutually opposite rotatable longitudinal sections in the implant, the implant cross-sections in the

Intermediate state are each rotated by an angle compared to the initial state. It can be provided, for example, that these rotatable longitudinal sections each lie in the area of the point of application of the compression force. In this case, the compression force could be exerted in such a way that it consists of two components of the same size, directed towards one another, which attach to opposite sides of the implant. The two

opposite longitudinal sections have the effect that upon the action of an external signal, such as a compression force, both longitudinal sections rotate by an angle a, whereby on the one hand the lateral dimensions of the

Implant can be further reduced and, on the other hand, the breaking of the

Implant is prevented in the two particularly stressed longitudinal sections. The two mutually opposite rotatable longitudinal sections can be arranged, for example, at an angle of 90 ° to the point of application of the compression force. The one rotatable longitudinal section could also in the

The point of application of the compression force can be provided, while the other would then be arranged opposite the point of application of the compression force.

Of course, it is not excluded that the implant has more than two longitudinal sections, for example 3, 4 or 5 longitudinal sections, in which there is a rotation through the angle α. It is also not ruled out that the implant has several pairs of opposing longitudinal sections which rotate through an angle α when an external signal is applied.

As a result, an implant of a suitable size is achieved, which enables a user to insert the implant into the cornea through a particularly small corneal gap, thereby complications associated with such

Implantation can be avoided if possible.

One embodiment of the implant is that it contains polymer material, in particular that it is made of polymer material. In order to ensure that the implant is particularly tolerable for the patient and not rejected by the body, one embodiment of the invention provides that the implant is made of a biocompatible polymer material.

Biocompatible means that the materials used to manufacture the implant, which are in direct contact with living tissues, do not have a negative impact on their metabolism. Examples of biocompatible materials that can be used to manufacture the implant are the materials mentioned above. The implant can be made from a polymer plastic, for example PMMA. It is also not ruled out that the implant comprises two materials, the material which is in direct contact with the living tissue, that is to say the cornea, being made of biocompatible material. Of course, it is also not ruled out that the implant consists of a material that is not a polymer, as long as this material is biocompatible, for example metals such as titanium, and a material according to the invention

Shape memory has.

Polymers usually consist of elongated or long-chain molecules (polymer molecules), which are always composed of the same monomer molecule, arranged one behind the other, and which essentially have a longitudinal dimension and a transverse dimension perpendicular to the longitudinal dimension, similar to a cylinder. The longitudinal extension (length of the polymer molecule) is

usually larger than the transverse dimension (diameter). The direction in which the longitudinal extension of a polymer molecule points is the orientation of the polymer molecule in relation to a specific reference axis. Such

In the case of the implant according to the invention, the reference axis can for example be the circumferential axis, that is to say the longitudinal axis of the implant along the circumference of the implant. The majority of the polymer molecules can be oriented in a specific direction or evenly distributed in all directions (randomly oriented). The measurement of the alignment of the polymer molecules in space with respect to a reference axis can be done, for example, by the diffraction of

electromagnetic waves can be measured on the molecules (A. Daxer and P. Fratzl. Collagen Fibril Orientation in the Human Corneal Stroma and its Implication in Keratoconus. Investigative Ophthalmology and Visual Science. 1997; 38: 121-129).

The polymer molecules in the implant can have a preferred orientation or preferred direction at least in sections along the ring circumference of the implant. This means that more polymer molecules with their longitudinal extension point in the preferred direction than in another direction. This

Preferred orientation of the polymer molecules can e.g. the longitudinal axis or

The circumferential axis of the implant or the circumference of the cross section, or in principle any other direction. The polymer molecules themselves can, however, also be curved or linearly shaped. The arrangement of the polymer molecules and their alignment can be at least partially along the circumference of the implant

Show trend patterns, for example by mostly following a certain pattern. For example, the polymer molecules could be arranged helically in that they are arranged, at least in sections, mostly in a helical manner along the circumference of the implant, that is to say around the circumferential axis

are aligned. The majority of them could also be oriented in a circular manner around the circumferential axis. In the case of at least partially spiral or

helical arrangement or alignment of the polymer molecules, it depends, for example, on the “pitch” of the windings whether the alignment of the polymer molecules are mostly parallel to the circumferential axis or perpendicular to it around the circumferential axis.

For example, an arrangement or alignment of the polymer molecules at least in sections along the circumferential axis of the implant can be produced in that the liquid, heated mass filled in a container is removed

Polymer material rotates around a certain axis during the cooling phase into the solid state - either with a stirrer or by rotating the container around an axis. By appropriately cutting out disks from the cooled solid block of polymer and then unscrewing the ring implants from the disks, different alignment,

Arrangement or size distributions of the molecules can be realized along the circumference. Instead of circular rotational forces, the material can also use other forces during cooling, e.g. Accelerating forces, are exposed in order to achieve a certain distribution of different molecule sizes or molecular arrangements or molecular orientations along the circumference or over the cross section of the ring implant.

Accordingly, the invention also comprises a method for producing an implant according to the invention, wherein in a polymer material before solidification by the action of an acceleration force (e.g. by rotation, linear

Acceleration, gravity) a certain orientation and / or arrangement and / or size distribution of polymer molecules is produced, the Polymer material is made to solidify in this state and then the implant is made from this solidified polymer material.

In order to achieve a particularly good breaking strength of the implant, it is provided in one embodiment of the invention that the arrangement and / or the alignment and / or the size distribution of the polymer molecules of the particularly biocompatible polymer material in a certain way at least

in sections along the circumferential axis of the implant or over the

Cross section of the implant is designed in a certain way. For example, the polymer molecules can at least in sections along the

The circumference of the implant, in particular around the entire circumference, can be aligned in a preferred direction depending on the rest of the structure, e.g. either

mostly in the direction of the longitudinal axis along the circumference (the circumferential axis) or also mostly not in the direction of the longitudinal axis along the circumference (the circumferential axis). For example, with a

helical or circular arrangement of polymer molecules depending on the angle of incline of the helical course, the polymer molecules either mostly in the direction or not in the direction of the longitudinal axis along the

Be arranged circumference. The majority of the polymer molecules are then arranged in the direction of the longitudinal axis along the circumference when the projection of the

Polymer molecules on just the long axis is larger than in any direction perpendicular to the long axis. Conversely, it is also true that the majority of the polymer molecules are not aligned along the longitudinal axis along the circumference when the projection of the polymer molecules in a direction perpendicular to

The longitudinal axis is larger than in the direction of the longitudinal axis. Strictly speaking, the direction of the longitudinal axis is to be understood as the direction of the tangent to the longitudinal axis at a certain point along the circumference of the implant, since the longitudinal axis is curved around the implant center or around the axis of rotation of the implant.

In order to achieve a particularly good breaking strength of the implant, it is provided in another embodiment of the invention that the arrangement and / or the alignment and / or the size distribution of the polymer molecules of the

in particular biocompatible polymer along the circumference of the implant or within the implant cross-section in different longitudinal sections of the Implant is different. The arrangement and / or the alignment and / or the size distribution of the polymer molecules of the in particular

biocompatible polymer along the circumference of the implant or within the implant cross-section in a rotatable longitudinal section of the implant may be different from another longitudinal section of the implant.

A different arrangement and / or orientation and / or size distribution of the polymer molecules leads to the fact that in certain longitudinal sections the

The breaking strength of the implant is higher than in other longitudinal sections. This means that in particular in those longitudinal sections which are through a

Rotate the action of force by an angle a from the initial state of the implant, an arrangement that is more advantageous compared to the other longitudinal sections,

Alignment or size distribution of the polymer molecules is present.

Different arrangement or orientation of the polymer molecules in different longitudinal sections is understood according to the invention to mean that, for example, in a first longitudinal section of the implant the polymer molecules are mostly oriented in a certain direction relative to the circumferential axis of the implant and in another longitudinal section in a different direction.

With different arrangements of the polymer molecules in different

According to the invention, longitudinal sections are understood to mean that, for example, the majority of the polymer molecules in a first longitudinal section of the implant have a different density (that is, more molecules per volume) than in another

Longitudinal section.

According to the invention, different size distribution of the polymer molecules in different longitudinal sections is understood to mean that, for example, the majority of the polymer molecules in a first longitudinal section of the implant have an essentially similar size, which differs from the size of the majority of the polymer molecules of a second longitudinal section. The relative composition of monomers, oligomers and polymers and / or the distribution of monomers, oligomers and polymers in different longitudinal sections and / or across an implant cross-section can also be different. In other words, in addition or as an alternative to the variation of the

Composition of monomers, oligomers and polymers in different longitudinal sections of the implant also provide that the implant has a different distribution of monomer molecules, oligomer molecules and polymer molecules on at least one longitudinal section along the circumference of the implant within the implant cross section. Additionally or alternatively, it can also be provided that the implant has a

has different density and / or has a different orientation of the polymer molecules.

In order to achieve a particularly good breaking strength of the implant, it is provided in one embodiment of the invention that the alignment of the

Polymer molecules in at least one rotatable longitudinal section largely circular around the circumferential axis of the implant and in at least one other

Longitudinal section is largely parallel to the circumferential axis of the implant.

The fact that at least one longitudinal section has polymer molecules oriented parallel to the circumferential axis and one longitudinal section circularly around the circumferential axis means that the implant does not break when a compression force is applied. The circularly arranged polymer molecules improve the elasticity of the material so that the implant does not break when the compression force is applied.

In order to achieve a particularly good breaking strength of the implant, it is provided in one embodiment of the invention that the implant has a material density which material density varies along the circumference of the implant and / or over the implant cross section. This means, for example, that the material density in a rotatable longitudinal section of the implant may be different from another longitudinal section of the implant. In particular, the material density can be lower there.

The different material density in the implant means that longitudinal sections with a lower material density endure a higher material compression due to the acting compression forces, whereby the breaking strength of the implant can be increased. It is particularly advantageous if the areas with lower material densities are arranged at the points which are exposed to increased stress during compression.

A variation in the material density along the implant cross-section causes the implant, on the one hand, to compress the material as a result of the acting

Compression force allows and on the other hand the simultaneously acting

Tensile forces caused by the compression force as well

is withstood, which increases the fracture strength of the implant.

In one embodiment of the invention it is provided that the implant along the circumference of the implant in at least one longitudinal section of the implant has an implant cross-section deviating from the rotational symmetry, so that the implant cross-section in a rotatable longitudinal section of the

Implant is different from another longitudinal section of the implant in order to further increase the fracture strength of the implant.

By in at least one longitudinal section of the implant from the

Rotational symmetry deviating implant cross-section is achieved that when compression force acts, the implant rotates at the longitudinal section predetermined by the deviating implant cross-section, whereby on the one hand a targeted reduction of the lateral dimensions of the implant is achieved and on the other hand through the rotation of the implant cross-section in one

predetermined longitudinal section the breaking of the implant is prevented, since in precisely this predetermined area the change in the implant cross-section results in a better adaptation to the compressive force acting on it

caused damage to the material is achieved.

In order to increase the stability of the implant when the lateral dimensions are reduced by the acting compression force, one embodiment of the invention provides that the implant in the initial state is designed as a complete ring with a uniform implant cross-section along the circumference of the implant, rotationally symmetrical about an axis perpendicular to the implant plane .

The fact that the implant has the same implant cross-section on each longitudinal section of the implant means that the implant is not rotated at a predetermined point when a compression force is applied, but rather rather, it can in principle rotate in every longitudinal section of the implant. This gives the user greater freedom of where he acts on the implant through compression force, i.e. the user does not have to find the location suitable for the effect of the compression force before reducing the lateral dimensions of the implant, but can apply the compression force at any longitudinal section of the implant Let it take effect, as each longitudinal section can withstand the increased strains equally well.

Of course, it can nevertheless be provided that the arrangement and / or the alignment and / or the size distribution of the polymer molecules of the biocompatible polymer along the circumference of the implant or within the implant cross-section, at least in sections along the circumference of the

Implant is different; or that the material density varies along the circumference of the implant and / or over the implant cross-section. In this way, at least one suitable rotatable longitudinal section can again be made available, which, however, then has to be identified by a marking.

In order to ensure particularly easy use and high wearing comfort of the

To ensure the implant, one embodiment of the invention provides that the implant is closed both geometrically and mechanically and has no discontinuity.

If the implant is designed to be closed both mechanically and geometrically, the implant has no ends which can interfere in any way with the wearer of the implant. In particular, a geometrically and mechanically closed implant ensures that the forces that act on the tissue are distributed over the entire circumference of the implant and are not concentrated at the ends.

In one embodiment of the invention it is provided that the implant has an inner edge, which inner edge delimits a surface, the surface delimited by the inner edge being flat in the initial state and curved in the intermediate state.

The shape memory of the implant according to the invention makes it possible for the implant to have at least two states, but better three states can assume, namely an initial state and an intermediate state and, ideally, another final state, this final state preferably corresponding exactly to the initial state. In order to enable even smaller lateral dimensions of the implant and thus an implantation over an even smaller corneal gap, the formation of a saddle shape of the implant is achieved through an intermediate state in which the implant plane is no longer flat. By directing two opposite longitudinal sections of the implant upwards, the lateral dimensions of the implant are reduced, while at the same time a high breaking strength of the material due to the rotation thereof

Longitudinal sections is guaranteed.

In order to achieve a particularly narrow implant in the intermediate state, which can be introduced into the cornea through an equally narrow corneal gap, one embodiment of the invention provides that a freely defined line L along the circumference in the initial state after compression with the compression force F becomes one Line L ^' along the circumference in

Intermediate state is twisted, the length of L ^'being greater than L.

This extension of the length L ‘is achieved by using a

(pseudo) elastic material in the manufacture of the implant. As a result of the rotation in the rotatable longitudinal section, when an elastic material is present, the implant is additionally stretched, as a result of which the length L is longer than the original length L. This lengthening also makes it easier

Deformability of the implant, as a result of which the implant has even smaller lateral dimensions for implantation in the cornea of the eye.

In order to achieve particularly suitable lateral dimensions of the implant for implantation in the cornea, it is provided in one embodiment of the invention that the compression of the implant achieved by the compression force in the direction of force without breaking through along the implant cross-section, depending on the material and geometry, is at least 5% , better at least 10% and ideally at least 20%.

In order to achieve particularly suitable lateral dimensions of the implant for implantation in the cornea, one embodiment of the invention provides that a rotation of the implant cross-section of the implant by impressing the Compression force takes place at least in sections by the angle a of at least 1 °, preferably at least 2 °, particularly preferably at least 3 ° and ideally at least 5 °.

It goes without saying that an implant which, in an intermediate state, has a rotation through the angle α of less than 1 ° or more than 5 ° is not excluded.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail on the basis of exemplary embodiments. The

Drawings are exemplary and are intended to explain the concept of the invention, but in no way restrict it or reproduce it conclusively.

It shows:

1 shows a rotation of the implant cross-section 1 by exercising a

Compression force F in the intermediate state

2a shows the relationships in a sectoral representation of the implant in FIG

Initial state

2b shows the relationships in a sectoral representation of the implant in

Intermediate state

3a shows a circumferential line L in the initial state of the implant

3b shows the rotation of the circumferential line L in L 'in an exemplary one

Intermediate state of the implant

3c shows the rotation of the circumferential line L in L 'in another exemplary embodiment

Intermediate state of the implant

4 shows the rotation of the implant cross-section on the basis of the rotation of any point X on the surface of the implant in

Initial state by the angle a to the position X 'in the intermediate state 5 shows the rotation of the implant cross-section on the basis of the rotation of a connecting line between two surface points R and S into the positions R 'and S'

6 shows the implant in various views in the initial state and in

Intermediate state

WAYS OF CARRYING OUT THE INVENTION

1 shows an implant according to the invention comprising any implant cross section 1, here oval. The hatched area shows the implant cross section 1 in the initial state. The ring-shaped implant (also referred to as a ring), which in principle can have any implant cross-section 1 (also referred to as a cross-sectional area), is designed so that it has a very specific one

Has shape memory. The shape memory of the implant can be achieved through the material used or the geometric properties or the internal structure or a special processing (e.g. temperature treatment) or a combination thereof.

In order to be able to use such materials for the purpose according to the invention, it is necessary to find and use further degrees of freedom of deformation, which increase the deformability and the breaking strength during deformation. In the

According to the present disclosure, a compression force F is converted into a deformation of the implant such that a rotation of the implant by one

Circumferential axis (longitudinal axis) 5 the compression of the implant to one

allows a sufficiently small lateral dimension without the implant breaking, which allows the implant to be implanted into the cornea through a narrow wound opening.

The at least partial rotation of the implant body along or around a circumferential axis 5 in the intermediate state by using a

Compression force F is achieved by the fact that a shape memory is impressed on the implant body, preferably during manufacture, at least in sections, which ensures that when a compression force F The desired rotation of the implant body, preferably around a circumferential axis 5, takes place at least in sections. This can be done by mechanical, thermal, electrical or some other physical or chemical treatment of the material or the implant, preferably, but not necessarily, during production. In principle, the implant can be made of any material, including plastic, metal, semiconductors, insulators, ceramics, biological materials (eg collagen), etc., that enables such a treatment. For example, in the case of a polymeric plastic, the alignment or arrangement or size distribution of the polymer molecules can be designed in such a way that an externally applied compression force F leads to a force distribution inside the implant from which the desired rotation of the

Implant body results. For example, the arrangement or alignment or size distribution of the polymer molecules can vary along the circumference or within the implant cross-section 1 at least in sections along the circumference. For example, the alignment of the polymer molecules can be designed at least in sections parallel to or circularly around a circumferential axis 5. Furthermore, for example, by varying the

Material density along the circumference or across the cross-section, the desired twist can be achieved. Materials that are e.g. through a

Phase transition of the 2nd order (martensitic phase transition) a certain shape can be imprinted by thermal or other physical treatments using a compression force in the sense of a shape memory material and in which, in the application case, the distortion is triggered by applying a corresponding compression force F.

The implant cross-section 1 of the implant can be any, e.g. circular, oval, as a polygon with or without rounded edges, convex on one side and straight or concave on the other, etc. (see. Fig. 1, 2a and 2b, Fig. 6). The implant can be bent as desired along a circumferential axis 5 (also referred to as an axis, center line, central axis, body axis or longitudinal axis) of the implant. However, this body or circumferential axis 5 preferably follows

Initial state of a constant curvature around the axis of symmetry 9 (also referred to as the axis of rotation) with an arc length of 360 °. The implant can have a variable or homogeneous cross section along this circumferential axis 5 exhibit. In the case of a homogeneous implant cross-section 1, both the cross-sectional shape, the alignment of the implant cross-section 1 with respect to the implant plane 8, and the size of the cross-sectional area along the circumference are the same.

The shape memory of the implant is characterized by the possible setting in at least two, preferably three, states, which can be converted into one another by an external signal (e.g. compression force F), FIG. 2a being an implant according to the invention in the initial state and FIG. 2b

shows the implant according to the invention in the intermediate state. The final state does not necessarily, but preferably again essentially correspond to that

Initial state, which is shown in Fig. 2a:

1. The initial state is the state in which the implant is designed as a ring implant which is arranged rotationally symmetrically about an axis of symmetry 9 and has an arc length of at least 350 ° and ideally 360 °

(shown in Fig. 2a). The implant will usually be flat in this condition, i.e. the implant plane is a flat surface.

2. Intermediate state is the state in which, through the imprinting of a

Compression force (transverse force) F in a point of application 13 can achieve a lateral compression of the rigid implant in the direction of force of at least 5%, better at least 10% and ideally at least 20% without breaking the implant by rotating the orientation of the implant cross-section 1 by one Angle a is triggered around a circumferential axis 5 (shown in Fig. 2b). This rotation by the angle a should preferably amount to at least 1 °, preferably at least 2 °, even more preferably at least 3 ° and ideally at least 5 °. By rotating the implant cross-section 1 or its orientation, it is possible to compress the inherently stiff implant so that it can be implanted into the cornea through the smallest possible wound opening without the implant breaking.

3. The final state is the state in which the implant is converted into a geometric state by removing the force F, in which it has the refractive power of Correct the cornea in the best possible way. The geometry of the final state of the implant can match that of its initial state.

2a shows an implant according to the invention in the initial state. The

Implant level 8 can in the initial state depending on the embodiment

can be determined in different ways. The implant plane 8 can thus be defined by the curved outer edge 2 between two points A and E separated from one another. This outer edge 2 runs between or along the points A, C and E. The implant plane 8 is the plane in which this outer edge 2 runs, or it becomes through the points A, C and E, which lie along this outer edge 2 , stretched. The implant plane 8 can also be curved through the

Inner edge 3 between two separated points B and F are defined. This inner edge 3 runs between or along the points B, D and F. The implant plane 8 is the plane in which the inner edge 3 runs, or it becomes through the points B, D and F, which lie along this inner edge 3 , stretched. The implant plane 8 is at least in the initial state perpendicular to the axis of symmetry 9 of the implant.

3a-c show the surface points X1 -X5 by a

acting compression force F caused rotation of the implant cross-section 1, FIG. 3a showing a section of an annular implant in the initial state, while FIGS. 3b and 3c show the implant in an intermediate state.

If in the initial state, a compression force F of

preferably over 1 mN or over 10 mN and if possible under 1.5 N, the direction of force of which is preferably in the implant plane 8, the ring-shaped geometry of the implant is deformed into a shape deviating from the ring shape, preferably largely oval, and it also occurs , at least in a ring area, but preferably in that where the force F applies, a rotation of the implant cross-section 1 by an angle α. The direction of rotation can be clockwise or counterclockwise. The rotation can act along a specific longitudinal section of the implant and thus lengthen the actual circumference that a specific neutral circumferential line L has before the compressive force is applied. Originally based on the neutral Surface points X1 to X5 running in the form of an annular circumference line L then run as X1 'to X5' along a spiral circumference line L '. A previously at least segmentally circular circumferential line L becomes an at least segmentally spiral circumferential line L '. In this way, the

Compression force F (also referred to as external force F) at least

converted in sections into an elastic rotational energy along a circumferential axis 5, whereby a further degree of freedom of the deformation is created, whereby the risk of breakage during implantation is reduced. In other words: If an implant were simply compressed from such a stiff material that is necessary in order to impress a certain shape on the cornea to correct the refractive power, it would not be possible to compress the implant to the required extent

compress without breaking. In particular in the longitudinal region 14, the

Ring area that is 90 ° to the direction of the force would be a

Bending stress occurs, which would very quickly lead to a material break in the longitudinal region 14. By the present invention, this compression in the inner area and the train in the outer area of the

Longitudinal region 14 a twist and thus an extension of the circular

Circumferential lines opposite in a compensatory manner, reducing the tension in the

Longitudinal region 14 and thus the risk of breakage is reduced.

The (elastic) stored in the intermediate state through the application of the compression force F in the rotation of the implant cross-section 1

When the compression force F is removed, torsional energy causes a

Restoring force F 'of at least 0.1 mN counter to the original direction of force to relax the compressed lateral dimension of the implant in a final state. Depending on the material, geometry and processing, this restoring force F ‘can be up to 1 N and more. The energy transferred to the implant by the compression force F due to the compression taking place is im

Intermediate state partially in an elastic torsional energy of the

Implant cross section 1 converted and saved. By removing the external force F, this torsional energy is released in the implant cross-section 1 as a restoring force F,, which puts the implant cross-section 1 in a final state, the geometry of which is preferably essentially that of the

The initial state. 4 shows a preferred embodiment of the invention, the rotation of a point X by an angle α to a point X 'being represented on the basis of a section of an implant according to the invention. An even more space-saving geometry of the implant is achieved by the action of the compression force F according to FIG. 4. The combination of the degree of freedom obtained from the rotation with the one thereby stored in the implant cross-section 1

Torsional energy and the degree of freedom obtained from the deflection of the longitudinal region 14 from the implant plane 8 with the deflection energy thus stored in the implant cross section 1 enables a particularly advantageous one

Deformation of the implant to even smaller lateral dimensions due to the compression force F, which enables particularly favorable surgical conditions for implanting the implant into the cornea through a narrow wound opening.

Particularly good ratios are achieved in this case if the

Compression force F perpendicular to the tangent 12 of the implant cross-section 1 at the attachment point 13 (also referred to as the point of application of the force) in the implant plane 8 is exerted. At least part of the compression force F should, however, apply in the implant plane 8 along a direction of force. 2a and 2b show that the connecting line 4, which lies between the original outer edge 2 and inner edge 3 or between points on the outer edge 2 and the inner edge 3, is at the angle a to the connecting line 4 'between 2' and 3 'Can set rotated relative to the original orientation of 4 or relative to the direction of force or relative to the axis of symmetry 9 or relative to the original implant plane 8 or any other specified direction. By exerting a compression force F, any point X on the surface of the implant rotates, at least preferably in the section of the implant where the compression force F applies, by the angle a to point X, as shown in FIG. In particular, by applying a compression force F to the implant, its direction of force at least with one component in the

Implant plane 8 is and at least one component is directed to the center point 9 'of the implant, or perpendicular to the tangent 12 at the attachment point 13 of the outer edge 2, the implant cross-section 1 by the angle a by a Adjusts circumferential axis 5 rotated so that a point X on the surface of the implant or on the boundary of the implant cross-section 1 migrates by the angle a into a position X 'relative to any reference point of the implant.

In other words, FIG. 5 shows: A straight line which runs through two different surface points R and S of the implant cross-section 1 and a point T which lies on the axis of symmetry 9 is twisted by exerting a

Compression force F on the implant cross-section 1 at an angle a in a straight line which runs through the surface points R 'and S' corresponding to R and S. R 'and S' represent the positions of the surface points R and S on the surface of the implant cross-section 1, rotated by the angle α, after the compression force has been exerted on the implant body. An extension of the connecting line of the rotated surface points R 'and S' does not necessarily have to be intersect the axis of symmetry 9. In addition, the point of rotation of the rotation does not necessarily have to coincide with the circumferential axis 5.

As described above, FIG. 4 shows a section of an implant according to the invention, the implant having an implant cross section 1, which implant cross section 1 is that cut surface through the implant which lies in a plane which, at least in the initial state, is perpendicular to the implant plane 8 and in which or parallel to which the axis of symmetry 9 runs. In other words, the implant cross-section 1 is a cut surface of the implant which lies in a plane perpendicular to the implant plane 8 and which is delimited by an outer edge 2 and an inner edge 3. The connecting line 4 lies between the outer edge 2 and the inner edge 3 in the direction of a diameter line of the implant (ie the line within which the greatest possible distance between two points on the outer edge 3 or between two points on the inner edge 2 lies and which is therefore preferably runs through the center 9 ^' ). By exerting a compression force F on the implant cross-section 1, a

Change of state to an intermediate state triggered in such a way, wherein the compression of the implant in the direction of force allows the

Implant cross section 1 of the implant at least in sections and preferably at the point of application 13 of the force F on the implant relative to the orientation of the

Implant cross-section 1 rotated by an angle a before the force transmission. This Rotation of the implant cross-section 1 by an angle a is shown in FIG. 1 and in FIG.

6 shown. The surface point X thereby moves to the position X ^' - rotated by the angle a (cf. FIG. 6).

In FIG. 5 it is shown that the twisting of the implant cross section 1 by the force F takes place in such a way that an extension of the connecting line between R ¹ and S ¹ also intersects the axis of symmetry 9 at a point T ¹ . Particularly good conditions result if the direction of force of F is at least one

Component lies in the implant plane 8 and at least one component is directed to the center point 9 ′ of the implant or perpendicular to the tangent 12 at the point of application 13 of the outer edge 2. The points R and S are then on the surface (boundary or the edge) of that cut surface (cross section) through the

Implant cross-section 1, at which a point of application 13 of the force F is also located.

6 shows the relationships in the initial state and in the intermediate state under certain and different conditions. Fig. 6 shows in the top

Representation of a top view of the ring-shaped implant in the initial state, in the middle figure the one in the initial state, cut in the middle

Implant in side view, the lower figure shows the implant in

Intermediate state. 6 discloses an annular implant, the implant being circular in the initial state. The one curved away from the implant body 1

The outer edge 2 represents the (convex) boundary. In the case of a regular curvature of the implant around the axis of symmetry 9, this boundary line has the greatest length, measured in mm. The (concave) delimitation curved towards the implant body 1 represents the inner edge 3. In the case of a regular curvature of the implant about the axis of symmetry 9, this delimitation line has the smallest length measured in mm. In other words, the outer edge 2 is represented by that boundary line of the implant which always measures the greatest distance from the center 9 ^'of the implant along the circumference. Correspondingly, the inner edge 3 is represented by that boundary line of the implant which always measures the smallest distance from the center 9 ^'of the implant along the circumference.

At least for the initial state, the following applies: The circumference, measured along the outer edge 2, should not exceed 30 mm if possible. The Inner diameter 11 should be larger than 3 mm and smaller than 10 mm if possible. The distance between the inner edge 2 and the outer edge 3 (also referred to as the ring width) measured along a diameter line should be less than 1.5 mm, better less than 1 mm and ideally less than 0.7 mm. The height of the implant is the greatest distance between 2 (opposite)

Surface points measured in the direction of the axis of symmetry 9 and lies between 50 pm and 500 pm. The diameter line runs as a straight line between two points on an outer or inner edge and includes the center point of the implant 9 ‘or at least one point of the axis of symmetry 9.

The middle and lower representation of FIG. 6 show that it may also be possible to trigger a deformation of the implant by the compression force F in such a way that in that longitudinal region (ring section) 14 of the implant that is perpendicular to the direction of the compression force F, the Implant cross-section 1 or the corresponding cross-section from the original planar or

two-dimensional implant plane 8 is deflected into a third dimension.

What is achieved thereby is that when the compression force F is applied, a largely saddle-shaped body is created instead of a purely oval implant shape (shown at the very bottom in FIG. 6). The straight and two-dimensional implant plane 8 of the initial state, in which the inner edge 3 or the outer edge 2 lies, and in which initial state the inner edge 3 and the outer edge 2 enclose a flat surface, is transferred to an intermediate state in which

In the intermediate state, a curved (curved) surface is created which extends in all three dimensions, in which the inner edge 3 and the outer edge 2 delimit a largely saddle-shaped surface (shown below in FIG. 6). The

Deflection of the longitudinal region 14, which is located orthogonally to the direction of force, from the two-dimensional ring plane 8 of the initial state is 90 ° to the

The direction of force or takes place in the direction of the axis of symmetry 9. At least part of the compression force F is converted into the elastic energy of the deflection of the longitudinal region 14 and stored in the intermediate state. In other words: If you were to simply compress an implant made of such a stiff material that is necessary to impress a certain shape on the cornea to correct the refractive power, the implant would break. In particular in the longitudinal region 14, the 90 ° to the force effect, a bending stress would occur, which would very quickly lead to a material breakage. Due to the deflection of the implant due to the shape memory in the longitudinal area 14 from the original ring plane 8 (also referred to as the implant plane) into the third dimension, this compression in the inner area and the tension in the outer area of the longitudinal area 14 (also referred to as the ring area and ring section) a relaxation by reducing the tension differences between tension and compression lines compensatory opposite, whereby the tension in the longitudinal region 14 is generally reduced and thus the risk of breakage. In addition, by applying a compression force F, a further degree of freedom is gained in that the implant is designed so that the

Implant cross-section, at least in a longitudinal section (in sections) is rotated by the angle a relative to the initial state. In a

Embodiment is through the application of a compression force F am

Point of application 13 of the implant both a rotation of the

Implant cross-section in a rotatable longitudinal section (in sections along the circumference) as well as a deflection of the implant body 1 in an implant section (longitudinal region) 14, which is located 90 ° to the force effect, in the direction of the axis of symmetry 9 from the implant plane 8.

In all embodiment variants and examples of the present invention, the compression force F can also consist of two oppositely directed, equally large components, which are located at opposite points of application 13 of the

Apply the implant, as shown for example in FIG. 6. This means that the connecting line between the opposing force components F runs through the center point 9 '.

The properties according to the invention give the implant increased deformability (compressibility) in an intermediate state, which makes it possible to implant the implant through a narrow wound opening. After the implantation in the cornea, in which the implant is in the intermediate state, through a narrow wound opening, when the compression force F is removed

Restoring force F ', which is at least partially directed against the original direction of force and which the implant by automatically unfolding into a

Final state shifted. The independent unfolding from an intermediate state in a final state is at least partially the result of the conversion of the (elastic) torsional energy stored in the implant cross section 1 through the application of the compression force F into a restoring force F '. The geometry of the initial state preferably largely corresponds to that of the final state.

It is explicitly stated that each described embodiment or each example or each property can be combined to form a further valid embodiment.

REFERENCE LIST

1 implant cross-section

2 outer edge without force

2 'outer edge when force is applied

3 Inner edge without any force

3 'inside edge when force is applied

4 Connection line between outer edge 2 and inner edge 3 without

Force effect

4 ^' connecting line between outer edge 2 and inner edge 3 at

Force effect

5 circumferential axis

6 Connection line between 2 selected points of the outer

Limitation

without force

6 'Line connecting 2 selected points of the outer

Limitation

with force

7 Connection line between 2 selected points of the inner

Limitation

without force

7 'connecting line between 2 selected points of the inner

Limitation

with force

8 implant level 9 axis of symmetry of the implant

9 'Center of the implant

10 outer ring diameter

11 Inner ring diameter

12 Tangent of the implant, which is perpendicular to the direction of a diameter

13 Point of application of the compression force on the implant perpendicular to the tangent

12

14 Longitudinal area that is 90 ° to the direction of the force

15 top edge

16 lower edge

F compression force (external force)

F 'restoring force

X surface point before deformation

X 'Position of the surface point X after deformation

L Connection between the surface points X (X1, X2, X3, X4, X5) along the circumference of the implant without any force

L 'connection between the surface points X (XT, X2', X3 ', X4', X5 ') along the circumference of the implant when force is applied

T, T 'points on the axis of symmetry 9

R, S Position of surface points on the implant before the force acts, the extended connecting line of which intersects with the ring axis 9 at a point T.

R ', S' Position of the surface points R, S on the implant after the effect of the force

(Angle)

Claims

EXPECTATIONS

1. Ring-shaped implant with shape memory for implantation in the

Cornea of the eye, wherein the implant spans an implant plane (8) in an initial state, and wherein the implant can be transferred from an initial state to an intermediate state in which the lateral dimensions of the implant are applied by applying a compression force (F) in the implant plane (8) measured in the direction of force are smaller than in

Initial state, characterized in that the alignment of an implant cross-section (1) in the intermediate state at least in one

rotatable longitudinal section along the circumference of the implant is rotated by an angle (a) with respect to the initial state.

2. Implant according to claim 1, characterized in that a

rotatable longitudinal section of the implant in the area of the point of application (13) of the compression force (F).

3. Implant according to claim 1 or 2, characterized in that there is a rotatable longitudinal section along the circumference of the implant outside of the point of application (13) of the compression force (F).

4. Implant according to one of claims 1 to 3, characterized in that the implant has two mutually opposite rotatable longitudinal sections in the implant, the implant cross-sections (1) in the

Intermediate state at an angle (a) with respect to the

Initial state are twisted.

5. Implant according to one of claims 1 to 4, characterized in that a rotatable longitudinal section at least over 5 °, better 10 ° and

ideally extends over 15 ° along the circumference of preferably 360 ° of the implant.

6. Implant according to one of claims 1 to 5, characterized in that the implant is made of a biocompatible polymer material.

7. Implant according to one of claims 1 to 6, characterized in that the implant has a specific arrangement and / or orientation and / or size distribution of polymer molecules, at least in sections along the circumference of the implant.

8. Implant according to one of claims 1 to 7, characterized in that the alignment of polymer molecules at least in sections

is mostly in a preferred direction.

9. Implant according to one of claims 1 to 8, characterized in that the alignment of polymer molecules at least in sections

is mostly not in the direction of the circumferential axis (5) of the implant.

10. Implant according to one of claims 1 to 9, characterized in that the alignment of polymer molecules at least in sections

is mostly in the direction of the circumferential axis (5) of the implant.

11. Implant according to one of claims 1 to 10, characterized in that the arrangement and / or the orientation and / or the size distribution of polymer molecules is different from another longitudinal section of the implant at least in a rotatable longitudinal section of the implant.

12. Implant according to one of claims 1 to 11, characterized in that the implant has a different composition and / or distribution of monomer molecules, oligomer molecules and along the circumference

Has polymer molecules and / or has a different density and / or has a different orientation of the polymer molecules.

13. Implant according to one of claims 1 to 12, characterized in that the implant has a different distribution of monomer molecules, oligomer molecules and polymer molecules on at least one longitudinal section along the circumference of the implant within the implant cross-section (1).

14. Implant according to one of claims 1 to 13, characterized in that the implant has a material density, which material density varies along the circumference of the implant and / or over the implant cross-section (1), so that the material density in a rotatable longitudinal section of the

The implant is different from another longitudinal section of the

Implant.

15. Implant according to one of claims 1 to 14, characterized in that the implant along the circumference of the implant in at least one longitudinal section of the implant is one of the rotational symmetry

different implant cross-section (1), so that the

The implant cross-section (1) in a rotatable longitudinal section of the implant is different from another longitudinal section of the implant.

16. Implant according to one of claims 1 to 15, characterized in that the implant in the initial state as a complete ring with a uniform implant cross-section (1) along the circumference of the implant

is designed to be rotationally symmetrical about an axis (9) perpendicular to the implant plane (8).

17. Implant according to one of claims 1 to 16, characterized in that the implant is closed both geometrically and mechanically and has no discontinuity.

18. Implant according to one of claims 1 to 17, characterized in that the implant has an inner edge (3), which inner edge delimits an area, the area delimited by the inner edge (3) in the

Initial state is flat and curved in the intermediate state.

19. Implant according to one of claims 1 to 18, characterized in that a freely defined line L along the circumference in the initial state after compression with the compression force (F) is twisted to a line L ^' along the circumference in the intermediate state, the length of L ^'is greater than L.

20. Implant according to one of claims 1 to 19, characterized in that the compression of the implant achieved by the compression force (F) in the direction of force without breaking through along the implant cross-section (1) is at least 5%, better at least 10% and ideally at least 20% % is.

21. Implant according to one of claims 1 to 20, characterized in that a rotation of the implant cross-section (1) of the implant by impressing the compression force (F) at least in sections by the angle a of at least 1 °, preferably at least 2 °, particularly preferably at least 3 ° and ideally at least 5 °.

22. The method for Fierstellung an implant according to any one of claims 1 to 21, characterized in that in a polymer material before

Solidification by the action of an acceleration force a certain

Orientation and / or arrangement and / or size distribution of

Polymer molecules is produced, the polymer material is made to solidify in this state and then the implant is made from this solidified polymer material.