FR2944428A1 - Intracrystalline i.e. phakic, implant for replacing or correcting optical function of crystalline lens of eye to treat astigmatism, has plating unit maintaining anterior and posterior capsules in remote manner - Google Patents

Abstract

An intracrystalline implant having an optical portion (36) defining an optical axis (3, 37) and adapted to be pressed against a posterior capsule (46) of the crystalline sac (31) and a haptic portion (4, 52) comprising at least a first and a second contact element (13, 13a, 16, 16a, 32, 33) for supporting the equatorial diameter (40) of the crystalline sac (31), the contact elements being coplanar and at an axial distance from each other. a median plane (27, 38a) of the optical portion (36); the haptic part comprising at least a first connecting arm (34) of the first contact element (32) to the optical part (36) and a second connecting arm (35) of the second contact element (33) to the optical part. . The first and second connecting arms are elastically deformable. The connecting arms and / or the contact elements have plating means (51) for the anterior capsule (46) of the crystalline sac (31), said plating means (51) projecting beyond the plane (38). ) contact elements (32, 33).

Description

Intracrystalline implant The invention relates to the field of intraocular implants. These implants are intended to replace or correct the optical function of the lens. They include an optical part and lateral attachment loops called haptic part. In a first aspect, the invention relates to the field of intracrystalline implants which are intended to replace the lens and are introduced into the crystalline sac after ablation of the crystalline material. Such implants are used for the treatment of cataracts. The crystalline sac is composed of two spherical caps interconnected called anterior capsule and posterior capsule. The crystalline sac is also called the capsular sac. This type of implant is called a crystalline implant or an intracapsular implant. Intracrystalline implants made of flexible material such as silicone or hydrophilic or hydrophobic acrylic materials, an example of which is known under the trademark HYDROGEL, are known, as described in patent application FR 2 748 200. It is desirable that the implant preserve the position in the eye initially planned by the surgeon. However, the inner equatorial diameter of the capsular bag of an adult individual capable of being operated can vary between 8.2 mm and 10.8 mm. In the case of crystalline implant cataract treatment, it is desirable that the haptic portion of a given lens implant be adapted to the different capsular bag diameters so that the range of implants suitable for cataract does not take into account than desirable optical characteristics.

In lens implants, another cause of diameter variation must also be taken into account. After placing the implant in the capsular bag, it tends to decrease in diameter in the months following the operation. This reduction in diameter is in particular due to postoperative scarring of the lens after recessing the opacified cells.

This reduction in diameter can reach 10%. The need exists for an intracapsular implant having a haptic portion which is deformed in such a way that, due to the reduction in the diameter of the capsular bag, no substantial displacement of the optical part occurs in the direction of its optical axis. , no radial shifting and no significant inclination of the optical axis of the implant with respect to the visual axis. For implants capable of correcting astigmatism, it must also be avoided that the adaptation to the diameter of the capsular bag is accompanied by pivoting in the frontal plane around the optical axis. Furthermore, it is desirable that intracrystalline implants for the treatment of cataracts contribute, once introduced into the capsular bag, to reduce the phenomenon of postoperative opacification. This phenomenon is due in particular to the migration of germinal cells located in the equatorial zone of the capsular bag. These cells have contributed to the formation of the cellular material of the lens of the fetus and are very resistant. After phacoemulsification and aspiration of the crystalline cell material, the capsular bag is emptied of its contents but the germinal cells remain in place. Germinal (epithelial) cells migrate to both anterior and posterior capsules. The epithelial cells are likely to be transformed into fibroblasts and myo-fibroblasts, causing postoperative opacification of the capsules of the crystalline sac outside and opposite the optical part of the implant. To solve this drawback, try to block the epithelial cell migration at the edge of the optics, and avoid the loss of transparency of the posterior capsule opposite optics, intracrystalline implants with square edges were developed. In particular, the studies conducted by Nishi et al., Were published in the journal Journal of Cataract Refract Surgery, volume 25 April 1999. This study suggests that it is possible to block the proliferation of cells on the posterior capsule of the crystalline sac thanks to the action of the edge of the optical part of the implant on said posterior capsule when this optical part comprises a so-called square edge. The term square edge has been adopted to define the edges of optical parts whose slice forms with the optical surface an angle close to 90 ° and which has kept a bright aspect.

Conjugation of the two capsules at the edge of the implant (capsulare bending) is another element of prevention of cell migration and opacification of the posterior capsule but it leads to a more or less marked opacification of the anterior capsule opposite. of the optics of the implant. In this technique, the migration of pathogenic germ cells is controlled by promoting the fusion of the anterior and posterior capsules in a radial zone beyond the lens. Indeed, once welded, the two capsules trap the pathogenic cells where they are. This stops the migration. The inventor has realized that this protection against the migration of pathogenic cells is insufficient because of the postoperative healing time leading to the fusion of the two capsules of the crystalline sac. In other words, the germinal cells may have already migrated to the optical part when the two capsules merge into the ring surrounding the optical part. The patent application FR 2 918 558 describes an intracrystalline implant having a circular haptic portion. Four arc-shaped contact elements have an outer edge intended to be in contact with the equatorial zone of the capsular bag. Each contact element is connected to the central lens by a single connecting arm having an S shape. Two consecutive contact elements are interconnected by connection elements of much lower rigidity than the contact element. When reducing the equatorial diameter of the capsular bag, the connecting arms are compressed and the flexible connection elements deform. Such an implant has the advantage of preventing the reduction in the diameter of the capsular bag from deflecting the implant and axially shifting its optical portion. In addition, the arcuate contact elements have a sharp edge between the rear face and an outer edge of the contact elements. Such a sharp edge, called a square edge, helps to block the proliferation of pathogenic germ cells in the equatorial zone of the capsular bag. The implant described above has another disadvantage.

When the contact elements are centripetally compressed, the optical portion pivots slightly about its axis. This type of implant is only suitable for lenses having a symmetry of revolution. This is not suitable for implants that can correct astigmatisms.

In a second aspect, the invention relates to the field of intraocular implants in general, and not only to intracrystalline implants. Indeed, other intraocular implants are intended to be introduced between the lens and the iris. The haptic part of such implants is intended to rest on the bottom of the ciliary canal. When such implants are inserted in front of a natural lens, it is called phakic implants. The ciliary muscle may continue to deform the natural lens. Phakic implants are used to correct myopia or hyperopia. They can also compensate for the irregularity of the corneal curvature to correct astigmatism. In the latter case, the lens of the implant is not symmetrical about the optical axis. Implants for correcting astigmatism are called toric implants. The implantation of such implants must be done by controlling the angular position of the lens of the implant around the optical axis. Other implants are also intended to be implanted at the bottom of the ciliary canal, but in combination with an intracapsular implant. This is called piggy back implants. Such implants may be used to supplement an optical correction provided by a lens implant. Indeed, crystalline implants are often limited in optical power. For example, when a +35 diopter correction is required, a +15 diopter piggy back implant can be used in combination with a +20 diopter lens implant.

Whether it is phakic implants, piggy back implants or crystalline implants, astigmatism correction requires control of the angular position of the implant during implantation in the eye and requires that this angular position obtained during the operation is stable over time. Other implants are intended to be fixed in the anterior cavity of the eye, that is to say in front of the iris, between the iris and the cornea. Such an implant is described in US Patent 4,575,374. Four handles protrude radially from the lens. The implant is held in the eye by the point ends of the four loops that are wedged between the iris and the cornea. Such an implant has the drawback of risk of irritating the eye and has given rise to a high percentage of clinical complications. DE 3 722 910 discloses an implant with a rigid polymethyl methacrylate (PMMA) lens and resilient haptic portions overlapping each other to reduce bulk during insertion of the implant into the eye. U.S. Patent 4,251,887 discloses an intraocular implant. A lens is held by two loops in the shape of a kidney. When inserting the implant into the capsular bag, the loops are compressed so that the width of the implant is solely due to the central lens which is rigid. A disadvantage of the implants described in documents DE 3,722,910 or US 4,251,887 is that their introduction into the eye requires an incision at least equal to the diameter of the lens. Another disadvantage of the three types of implants mentioned above is that the loops are very strongly deformed during the introduction of the implant through the incision of the capsular bag. Once the implant deployed inside the crystalline sac, the final position of the lens is due to the symmetry of the deployment of the two loops on a very important deformation loop of the handles. However, the possible contacts between the implant and the ocular tissue may not be totally symmetrical. This may result in inaccuracy of the centering of the lens relative to the visual axis. Whether it is an intracapsular implant, a piggy back implant, or a phakic implant, it is desirable that the intraocular implant retains the position in the eye initially planned by the surgeon. However, the inner equatorial diameter of the capsular bag and the diameter of the ciliary furrow vary from one individual to another. For example, the diameter of the ciliary furrow varies from 10.5 mm to 12 mm from one individual to another. The equatorial diameter of the capsular bag of an adult individual that can be operated can vary between 8.2 mm and 10.8 mm. In the case of crystalline implant cataract treatment, it is desirable that the haptic portion of a given lens implant be adapted to the different capsular bag diameters so that the range of implants suitable for cataract does not take into account than desirable optical characteristics. According to a first aspect, the invention provides an intracrystalline implant that overcomes the aforementioned drawbacks. An object of the invention, according to this aspect, is to provide an implant that reduces postoperative opacification, especially those due to the proliferation of germinal cells.

According to one embodiment, the intracrystalline implant has an optical portion defining an optical axis and intended to be pressed against a posterior capsule of the crystalline sac and a haptic portion comprising at least a first and a second contact element intended to serve as a support on the equatorial diameter of the crystalline sac. The contact elements are coplanar and at axial distance from a median plane of the optical part. The haptic portion comprises at least a first connecting arm of the first contact element at the optical portion and a second connecting arm of the second contact element at the optical portion. The first and second connecting arms are elastically deformable. The connecting arms and / or the contact elements have means for plating the anterior capsule of the crystalline sac, said plating means being projecting beyond the plane of the contact elements. Surprisingly, the inventor realized that it was also possible to slow down the migration of germinal cells towards the optical part, especially along the anterior capsule, by preventing this capsular fusion, and not by promoting this fusion as in the prior art called capsulor bending. The implant of the invention comprises plating means projecting beyond the plane of the contact elements, that is to say on the side of the plane of contact opposite the median plane of the optical part. Thus, the plating means now removes the anterior and posterior capsules and prevents any contact of the anterior capsule with the optics of the implant. This makes it possible to keep the transparency of the entire capsular bag and not only of the posterior capsule opposite the optics.

Such an embodiment contributes to curbing the migration of germinal pathogenic cells in the non-protected area by the contact elements, and this whatever the form that the connecting arms in the radial plane. According to one embodiment, at least one connecting arm has a corrugation projecting axially from the plane of the contact elements in the opposite direction to the median plane of the optical part. The corrugation makes it possible to lift the anterior capsule and to prevent fusion between the anterior and posterior capsules of the crystalline sac, the corrugation projecting beyond the plane of contact takes place on the connecting arms, that is to say -describe at a place where the contact elements do not exert pressure to slow the migration of pathogenic cells. The protruding ripple keeps the anterior capsule of the posterior capsule at a distance. This prevents the fusion of the two capsules of the crystalline sac at this point. According to one embodiment, the optical portion has a sharp end of connection between an outer sidewall and a posterior diopter axially opposed to the contact elements. The periphery of the optical portion has a square edge. This constitutes a second blocking zone for the migration of the germinal cells, in addition to the blockage exerted by the contact elements in an arc of a circle. According to one embodiment, the first and second connecting arms are symmetrical to one another with respect to a plane of symmetry passing through the optical axis and the optical portion is elastically foldable relative to the plane of symmetry of the arms. connection. It is understood that the optical portion can fold relative to a plane of symmetry of the connecting arms, the size of the folded implant is reduced by half. The two arms are superimposed during insertion through the incision of the eye. The elasticity of the lens allows the entire implant to deploy after insertion into the eye. The contact elements then bear against the implantation diameter according to the type of implant. The implantation diameter may be in particular the ciliary sulcus or the equatorial diameter of the crystalline sac. The actual implantation diameter is less than or equal to the inscribed diameter passing through the different contact elements in the non-implanted state. Thus, the deployment of the implant until contact of the contact elements against the implantation diameter is accompanied by compression of the connecting arms. The elasticity and symmetry of the arms allow the lens to remain not only centered in the middle of the support circle, but also to undergo no pivoting around the optical axis.

In addition, the elasticity and symmetry of the arms also guarantee the centering and non-postoperative rotation of the lens during the healing of the crystalline sac. According to one embodiment, the haptic part comprises two pairs of U-shaped handles, each U-shaped hinge being connected to the optical part only by one end of a U-shaped limb, the other limb of the U forming the element of contact. Convex surfaces of the two handles of a pair are turned toward each other. According to one embodiment, all the contact elements have an arcuate shape and are arranged in the non-implanted state on the same circle, each of the contact elements extending over an angular sector of plating (a, ( 3) at least 8 degrees around the optical axis, preferably the arcuate shape of the contact elements is tangent to the circle concentric with the optical axis, so that each contact element is parallel to the diameter of the optical axis. implantation The plating force at the bottom of said diameter is distributed over at least 8 ° of angle This strongly reduces the mechanical stresses to the tissues of the eye during fixation of the implant, and this, what According to one embodiment, the first and second connecting arms each have at least one flexibility zone (a, b, dg) in a plane perpendicular to the optical axis, the thickness considered. perpendicular to the optical axis, arm in the area or zones of flexibility being smaller than the smallest thickness perpendicular to the optical axis of the contact elements. This allows the contact element to be less deformed than the connecting arm when adapting the haptic loops to the implantation diameter. This reduces the risk of hurting the eye. Advantageously, at least one flexible zone of a connecting arm is connected to the optical part at a distance of at least 15% of the distance between the circle and the periphery of the lens of the optical part. According to one variant, the connection arms each have a single zone of flexibility extending over a length greater than 0.6 times the radial distance between the optical part and the contact element corresponding to the non-implanted state.

Such an elongated area of flexibility allows that the centripetal displacement of the contact element is accompanied by a sliding of the end of the contact element around the optical axis. Thus, the arm can not only bend as the two branches of a U or a V approach, but also unfold like a caterpillar. This type of connection arm is particularly useful for accompanying the deformation of large contact elements covering for example an angular sector between 60 ° and 110 ° and connected to the optical part by two connecting arms at both ends of the contact element.

According to another variant, the first and second connecting arms each have a first and a second one of said zones of flexibility, distant from each other, the first zone of flexibility being further from the plane of symmetry than the second zone of flexibility, the area of flexibility being disposed in the vicinity of a junction between the contact element and the connecting arm.

The contact element pivots around the flexibility zone near the junction with the arm. The connecting arm pivots around the first flexibility zone. Advantageously, the first flexibility zone is closer to the optical portion than the second. The contact element can move almost parallel to itself, to remain tangent to the implantation diameter. This avoids hurting the eye despite the adaptation of the implant implantation diameter of the individual operated, or despite the postoperative reduction of the capsular bag.

According to one embodiment, the haptic part comprises at least two first connection arms connecting the ends of the first contact element to the optical part and two second connection arms connecting the ends of the second contact element to the optical part.

According to a second aspect, the invention provides an intraocular implant, in particular a phakic or piggy back implant or a crystalline implant that overcomes the aforementioned drawbacks. One aim of the invention, according to this aspect, is to propose an intraocular implant compatible with the treatment of astigmatism, the haptic part of which of the same implant is likely to be suitable for several patients belonging to a given pathology and who reduce the incision size required for implantation.

According to one embodiment, the intraocular implant has an optical part defining an optical axis and a haptic part comprising at least a first and a second contact element intended to serve as a support for fixing the implant in the eye . The haptic portion comprises at least a first connecting arm of the first contact element at the optical portion and a second connecting arm of the second contact element at the optical portion. The first and second connecting arms are elastically deformable and symmetrical to one another with respect to a plane of symmetry passing through the optical axis. The optical portion is elastically foldable relative to the plane of symmetry of the connecting arms.

It is understood that the optical portion can fold relative to a plane of symmetry of the connecting arms, the size of the folded implant is reduced by half. The two arms are superimposed during insertion through the incision of the eye.

The elasticity of the lens allows the entire implant to deploy after insertion into the eye. The contact elements then bear against the implantation diameter according to the type of implant. The implantation diameter may be in particular the ciliary sulcus or the equatorial diameter of the crystalline sac. The actual implantation diameter is less than or equal to the inscribed diameter passing through the different contact elements in the non-implanted state. Thus, the deployment of the implant until contact of the contact elements against the implantation diameter is accompanied by compression of the connecting arms. The elasticity and symmetry of the arms allow the lens to remain not only centered in the middle of the support circle, but also to undergo no pivoting around the optical axis. In the case of intracapsular implant, the elasticity and symmetry of the arms also guarantee the centering and non-postoperative rotation of the lens during the healing of the crystalline sac. Advantageously, all the contact elements have an arcuate shape and are arranged in the non-implanted state on the same circle, each of the contact elements extending over an angular sector of plating of at least 8 degrees around the optical axis. Thus, each contact element is parallel to the implantation diameter. The plating force at the bottom of said diameter is distributed over at least 8 ° angle. This greatly reduces the mechanical stress experienced by the tissues of the eye during fixation of the implant, regardless of the location. Advantageously, the first and second connecting arms are designed so as to be able to abut one against the other. The contact occurs without overlapping when a radially oriented force is exerted simultaneously on the first and the second contact element. This makes it possible to fix a minimum implantation diameter corresponding to the contact between the two arms of the pair of contact elements. This avoids excessive deformation of the haptic part. This improves control of centering and non-pivoting of the lens around the optical axis.

For implants of the phakic or piggy back type, implant manufacturers can develop several sets of implants, each suitable for individuals with ciliary furrows in a given range, for example: [10.5-11mm], [11- 11.5mm], [11.5-12mm]. The haptic part of the implant is identical for all implants of a given series. The elasticity of the connecting arms allows the implant to press against a ciliary groove whose actual diameter is between a maximum implantation diameter and a minimum implantation diameter corresponding to the series. Improved centering and non-pivoting of the lens improves the performance of the implant, especially multifocal implants. Advantageously, the first and second connecting arms each have at least one flexibility zone in a plane perpendicular to the optical axis, the thickness considered perpendicular to the optical axis of the arms in the zone or zones of flexibility, being less than the smallest thickness perpendicular to the optical axis of the contact elements. This allows the contact element to be less deformed than the connecting arm when adapting the haptic loops to the implantation diameter. This reduces the risk of hurting the eye. According to a variant, the first and second connection arms each have a first and a second of said flexibility zones, distant from each other. The first zone of flexibility is further from the plane of symmetry than the second. The second zone of flexibility is disposed in the vicinity of a junction between the contact element and the connecting arm. The contact element pivots around the flexibility zone near the junction with the arm. The connecting arm pivots around the first flexibility zone. Advantageously, the first flexibility zone is closer to the optical portion than the second. The contact element can move almost parallel to itself, to remain tangent to the implantation diameter. This avoids hurting the eye despite the adaptation of the implant implantation diameter of the individual operated, or despite the postoperative reduction of the capsular bag.

According to a particular embodiment, the haptic part comprises two pairs of U-shaped handles, each U-shaped handle being connected to the optical part only by one end of a branch of the U, the other branch of the U forming the element of contact. Convex surfaces of the two handles of a pair are turned toward each other. Advantageously, the axial thickness of the contact elements is less than 200 m, and preferably less than 120 m. This is particularly suitable for implantation in the ciliary sulcus.

Advantageously, the haptic portion extends, perpendicularly to the optical axis, over a width less than or equal to the width of the optical portion. This facilitates the introduction of the implant through an incision of the eye. According to another particular embodiment, the implant comprises at least one pair of contact elements in the form of coplanar circular arcs. Each of said contact elements is elastically deformable and connected to the optical portion by two connecting arms symmetrical to each other with respect to a plane of symmetry of the contact element.

This type of implant is particularly suitable for implantation in the capsular bag. It will be understood that, when the contact elements are plating at the bottom of the equatorial inside diameter of the capsular bag, the flexibility of the contact elements, perpendicular to the optical axis, makes it possible to adapt the radius of curvature of the circular arc of the contact element with real equatorial diameter of the operated capsular bag. In addition, the presence of at least one zone of flexibility in the connecting arms causes them to deform primarily. The two ends of the two contact elements come closer to each other to fit the equatorial perimeter of the capsular bag. In other words, the contact elements are almost perfectly plated at the bottom of the equatorial diameter of the capsular bag. This pressure effect helps to slow the migration of pathogenic cells over the entire length of the arc of the contact element. The blocking of the migration of the germinal cells is thus suspended in only two places and not in four places as in the prior art described in the document FR 2 918 558. According to one embodiment, the first and second connecting arms present each has a single zone of flexibility extending over a length greater than 0.6 times the radial distance between the optical portion and the contact element corresponding to the non-implanted state. Such an elongated area of flexibility allows that the centripetal displacement of the contact element is accompanied by a sliding of the end of the contact element around the optical axis. Thus, the arm can not only bend as the two branches of a U or a V approach, but also unfold like a caterpillar. This type of connection arm is particularly useful for accompanying the deformation of large contact elements covering for example an angular sector between 60 ° and 110 ° and connected to the optical part by two connecting arms at both ends of the contact element. Advantageously, the contact elements are situated in the same plane of contact axially offset with respect to a median plane of the optical part. When the implant is inserted into a capsular bag, this allows the optical part of the implant to be pressed against the posterior capsule of the lens sac. Advantageously, the optical portion has a sharp end of connection between an outer side of the lens and a posterior diopter axially opposed to the contact elements. The periphery of the optical portion has a square edge. This constitutes a second blocking zone for the migration of the germinal cells, in addition to the blockage exerted by the contact elements in an arc of a circle. Advantageously, the thickness considered perpendicular to the optical axis in the flexibility zone or zones of the first and second arms is less than the axial height of the arm in the same zone of flexibility. In other words, a connecting arm can thus be very flexible to accompany a displacement of the contact elements perpendicular to the axis while having a high axial stiffness. This reduces or even eliminates the axial displacement of the lens during adaptation to the implantation diameter or during the post-operative contraction of the equatorial diameter of the crystalline sac. Other features and advantages of the invention will appear on reading the following description of several embodiments of the invention, given by way of non-limiting examples. The description refers to the accompanying drawings in which: - Figure 1 is a front view of a phakic implant illustrating the adaptation to the diameter of the ciliary groove; - Figure 2 is a cross section of the implant according to Figure 1, implanted in an eye; FIG. 3 is a side view of an implant according to FIG. 1 implanted in an eye; FIG. 4 is a perspective view of a crystalline implant; FIG. 5 is a front view of a variant of a crystalline implant illustrating the adaptation to the diameter of the crystalline sac; and FIG. 6 is a side view of a crystalline implant implanted in an eye.

As illustrated in FIG. 1, the implant 1 comprises an optical part 2 also called lens 2, of circular shape of revolution about an optical axis 3 perpendicular to FIG. 1. The implant 1 also has a haptic part 4 consisting of two pairs of handles 5, 5a diametrically opposed. Each pair of handles 5, 5a are respectively composed of a first individual loop 6, 6a and a second individual loop 7, 7a. The first individual loops 6, 6a are symmetrical with the second individual loops 7, 7a with respect to a plane of symmetry 8 of the implant 1 passing through the optical axis 3.

Each of the individual loops 6, 6a, 7, 7a has a general U shape connected to the lens 2 only by one end of one of the branches of the U, the other branch of the U being, in the non-implanted state, drawn in bold lines in FIG. 1, tangential to a circle 10 concentric with the optical axis 3. The first individual loops 6, 6a have a tapered shape extending from a periphery 9 of the optical portion 2 to the circle 10 and comprise successively a first connection base 11, 11a, a first connecting arm 12, 12a and a first contact element 13, 13a. Similarly, the second individual loops 7, 7a comprise successively from the periphery 9 to the circle 10 a second connection base 14, 14a, a second connecting arm 15, 15a, and a second contact member 16, 16a. Each of the contact elements 13, 13a, 16, 16a has an elongated shape tangent to the circle 10 over an angular sector of plating a greater than 8 °. This avoids hurting the tissues of the eye. The ends of the contact elements 13, 13a, 16, 16a farthest from the plane of symmetry 8 are at a distance from the plane of symmetry 8 less than or equal to the radius of the lens 2. This allows that by folding the lens 2 around the plane of symmetry 8, the haptic portion 4 is not more bulky in the width direction than the folded lens 2. This reduces the size of the incision of the eye. The connecting arms 12, 12a, 15, 15a are constituted by the bottom of the U-shape and the U-arm opposite that of the contact element 13, 13a, 16, 16a. The connecting arms 12, 12a, 15, 15a have a first zone of flexibility illustrated in (a) in FIG. 1, individual loops 6, 6a, 7, 7a in the plane of FIG. 1 perpendicular to the optical axis. 3. The first flexibility zone (a) corresponds to a zone of lesser thickness perpendicular to the optical axis 3 between the connection base 11, 11a, 14, 14a and a central part of the connecting arms. The connecting arms 12, 12a, 14, 14a also comprise a second zone of flexibility illustrated in (b) in Figure 1, and located in the vicinity of the end of the contact elements 13, 13a, 16, 16a.

The connection bases 11, 11a, 14, 14a are respectively located at the hourly positions corresponding to approximately 1 hour, 5 hours, 7 hours and 11 hours. The connection base 11, 11a, 14, 14a protrudes radially from the periphery 9 of the lens 2 so that the corresponding first flexibility zone (a) is located radially at least 15% of the distance between the circle 10 and the periphery 9 of the lens, and preferably around 20% of this distance. The first flexibility zone (a) is further from the plane of symmetry 8 than the second flexibility zone (b). The two zones of flexibility (a) and (b) are distant from each other. The fact that the first zone of flexibility (a) is remote from the periphery 9 of the lens 2 makes it possible to increase the inclination of the connecting arms 12, 12a, 15, 15a with respect to the plane of symmetry 8.

We will now describe the deformation of the haptic portion 4 during the implantation of the implant 1 in an implantation diameter 17. The expression diameter of implantation is a shape that is not necessarily circular, because the equatorial diameter of the crystalline sac or the diameter of the ciliary furrow, are generally slightly elliptical. The surgeon determines the orientation of the major axis of the implantation ellipse 17. The pairs of loops 5 and 5a are intended to be oriented in the direction of the major axis of the implantation ellipse 17. The angular orientation relative of the optical part 2 with respect to the plane of symmetry 8 is determined case by case for each individual. The fact that the pairs of loops 5, 5a are diametrically opposed and intended to be implanted in the long axis of the implantation ellipse 17 makes it possible to stabilize the angular orientation of the implant 1 in the eye. During implantation, the contact elements 13, 13a, 16, 16a are concentrically compressed by the implantation diameter 17 so that the second articulation zone (b) moves in (b ') by pivoting around the first articulation zone (a). The optical part 2 does not pivot around the optical axis 3.

The fact that the individual loops are symmetrical with respect to the plane of symmetry 8 allows them to abut against each other without overlapping, as illustrated in dotted lines in FIG. 1. This maximum compression position corresponds to the implantation diameter 17 minimum for a series of implants considered. Thus, the deformation of the haptic portion 4 is limited to the displacement of (b) to (b '). This limited displacement makes it possible to have a first zone of flexibility (a) having a stiffness in the deformations perpendicular to the relatively high optical axis, and identical for the four individual loops. This makes it possible to have identical loops irrespective of the individual to be operated, having implantation diameters between the minimum implantation diameter 17 and the maximum implantation diameter 10. This relatively high stiffness of the first flexibility (a) makes it possible to guarantee the centering of the lens 2 at the center of the implantation diameter 17.

As illustrated in FIGS. 2 and 3, the embodiment described in FIG. 1 may be implanted in a ciliary groove 20 situated axially between the iris 21 and the ciliary muscle 22 of the eye. The lens 23 is circumferentially connected to the ciliary muscle 22 by a zonule 24 made of filaments that relax when the ciliary muscle 22 contracts. This allows the curvature of a young natural lens to increase to accommodate an image in near vision. The lens 2 is of the convex-concave type, with a radius of curvature of the concave diopter smaller than that of the convex diopter. The optical portion 2 of the implant 1 is axially supported on a central zone of the lens 23 by its concave diopter. The convex diopter of the lens 2 is located on the side of the iris 21. The value of the radii of curvature is adapted to the number of diopters to be corrected. The space between the lens 23 and the concave diopter of the lens 2 varies from 150 microns to 450 microns depending on the optical correction required. The diameter of the ciliary sulcus 20 varies from one individual to another and also varies according to the contraction of the ciliary muscle 22. For example, for a young person who is not presbyopic, the diameter of the ciliary sulcus may be 10.2 mm. at 9.85 mm when the ciliary muscle 22 contracts for near vision. In the implants which are the subject of the invention, the lens 2 hardly deforms during the concentric compression of the contact elements. The contact elements adapt to this variation in the diameter of the ciliary groove without causing displacement of the implant. Although foldable, the lens 2 has a radial stiffness much higher than the individual handles 6, 6a, 7, 7a. The haptic part 4 permanently deforms under the effect of the contraction of the ciliary muscle 22. The contact elements 13, 13a, 16, 16a have a particularly thin axial thickness, of the order of 100 microns, so as not to not distending the tissues of the eye around the ciliary furrow 20 because of their presence. The aqueous humor of the eye is generated in the zone of the ciliary groove 20. In normal operation, this aqueous humor flows radially between the lens 23 and the iris 21 and joins the cornea 25 through the central opening of the eye. Due to the presence of the lens 2 between the central opening of the iris 21 and the lens 23, the surgeon can proceed to open an orifice 26 in the iris (iridectomy) so as to that the aqueous humor generated at the ciliary sulcus 20 can join the cornea 25 more easily. As illustrated in FIG. 3, the median plane 27 of the lens 2 is axially offset with respect to the ciliary groove 20. The value of this axial offset is not the same for phakic implants (or for implants of the piggy back type). because of the thickness of the natural lens 23 or its replacement by an intracapsular implant. FIG. 4 to 7 will now describe an implant 30 intended to be introduced inside the crystalline sac 31 (visible in FIG. 6). The implant 30 comprises a first contact element 32 and a second contact element 33, in the form of coplanar circular arcs. The implant 30 has an optical portion 36 centered about an optical axis 37. The optical portion 36 has a median plane 38a axially offset with respect to a plane 38 of the contact elements 32, 33. Two first connecting arms 34 and 34a connect each of the ends of the first contact element 32 to the optical part 36. Two second connection arms 35 and 35a connect each of the two ends of the second contact element 33 to the optical part 36. Each of the connecting arms 34, 34a , 35, 35a has a generally U-shaped shape, one branch of which is in the extension of the corresponding contact element, and the other branch of which is connected to a connection base 39 projecting radially from the optical part 36. The elements contact 32, 33, the connecting arms 34, 34a, 35, 35a and the connection bases 39 form a haptic portion 52 of the implant 30. The following will now be described with reference to FIG. at rest and the deformation of the connecting arms 34, 34a, 35, 35a, when the contact elements 32, 33 plate at the bottom of an equatorial diameter 40 of the crystalline bag 31 (visible in Figure 6).

The neutral line of the connecting arms passes through points c, d, e, f, h. The connecting arms have an elongated flexibility zone (cg) extending from point (c) to point (g) and having a thickness, considered perpendicular to the optical axis 37, less than two-thirds of the thickness of the elements. contact 32, 33. This thickness may be substantially constant along the flexibility zone (cg). The connecting arms 34, 34a, 35, 35a have regions of progressive enlargement of thickness between the points (g) and (h) in the extension of the corresponding contact element and between the points (d) and (d). c) to connect to the corresponding connection base 39. The first and second connecting arms 34, 35 form a pair of connecting arms 43 symmetrical with respect to a plane of symmetry 41 of the connecting arms. Similarly, the first and second connecting arms 34a and 35a form a pair 43a of connecting arms symmetrical with respect to the arm plane of symmetry 41. Each pair of connecting arms 43, 43a has a convex face facing the one of the other and turned towards the plane of symmetry of the arms 41. In addition, the first and second contact elements 32, 33 are both symmetrical with respect to a plane of symmetry 42 of the contact elements perpendicular to the plane of symmetry 41 of the connecting arms. When the contact elements 32, 33 plate at the bottom of the equatorial diameter 40 of the crystalline bag 31, they are subjected to a centripetal pressure causing the flexion of the connecting arms 34, 34a, 35, 35a and the curvature of the elements of the contact 32, 33. The contact elements 32, 33 in the non-implanted state are inscribed in a diameter 44, corresponding to the maximum implantation diameter to which the implant 30 illustrated can fit.

Diameter 45 is the minimum implant diameter at which implant 30 can fit. For example, the minimum implantation diameter 45 is 8.5 mm, the maximum implantation diameter 44 is 10.8 mm. The diameter of the optical portion 36 is 6 mm. The contact elements 32, 33 in the form of an arc extend, in the non-implanted state, over an angular sector of plating P greater than 60 °, preferably greater than 90 ° and approximately 110 °. When the implant 30 is inserted in a crystalline bag 31 whose equatorial diameter 40 is between diameters 44 and 45, the connecting arms are deformed between the extreme positions illustrated in FIG. 5. The points d, e, f, g, h move respectively to the points of, e ', f', g ', h'. The position of the point (h ') is imposed by the stiffness of the contact elements 32, 33, greater than that of the connecting arms. Around the point (e '), the connecting arm 34, 34a, 35, 35a is extended and the material is compressed on the outside of the connecting arm. In the vicinity of the point (f '), the connecting arm 34, 34a, 35, 35a is folded back on itself and the material is compressed on an inner face of the connecting arm. In other words, the initial shape c, d, e, f, g, h, substantially in U, unfolded like a caterpillar, by sliding the arms of the U, bringing them together and shifting them parallel to each other. the other. The point (h) has moved in (h ') so as to approach both the optical axis 37 and the plane of symmetry 41 of the arms.

The minimum implantation diameter 45 to which the implant 30 can fit corresponds to a contact of the connecting arms of the same pair 43 or 43a, one 34, 34a against the other 35, 35a. As illustrated in FIG. 6, the crystalline sac 31 comprises a posterior capsule 46 and an anterior capsule 47 on the side of the iris 21. The optical part 36 is pressed against the posterior capsule 46 thanks to the axial displacement between the contact plane 38 and the median plane 38a of the lens 36. The lens 36 has an outer flank 48 extending axially over the entire periphery of the lens 36. The connecting edge between the outer flank 48 and the posterior diopter of the lens 36 is a sharp edge. It is said that the lens 36 has a square edge. Similarly, the contact elements 32, 33 have an axially extending outside flank 49 and a posterior flank 50 extending radially on the side of the lens 36. The connection between the outer flank 49 and the posterior flank 50 is a ridge vivid. This forms a square edge which is an obstacle to the migration of germinal cells along the posterior capsule 46. Thus, the square edge of the lens 36 and the square edge of the contact elements 32, 33 constitute two successive barriers to the postoperative opacification of the posterior capsule 46 at the location of the optical axis 37. The connecting arms 34, 34a, 35, 35a also have a corrugation 51 protruding radially from the contact plane 38 in the axial direction opposite to the lens 36. The corrugation 51 makes it possible to keep the anterior capsule 47 at a distance from the posterior capsule 46 and at a distance from the lens 36. The corrugation 51 contributes to reducing the migration of the germinal cells in the zone between the elements of the contact 32, 33. A non-illustrated variant of the embodiment of Figures 4 to 7 is that the arms 34, 34a, 35, 35a are not in the extension of the elements of corresponding contact 32, 33. However, the connecting arms remain symmetrical two by two with respect to the plane of symmetry 41. In this variant, the contact elements have junctions with the connecting arms remote from the arc end of circle. In other words, the arcuate contact elements have two end portions beyond the junction of the connecting arms. When adapting the haptic portion to the implantation diameter, the connecting arms are deformed as in FIG. 5. However, the end portions of two contact elements facing each other relative to the plan 41 are not symmetrical with respect to the plane 41. The end portions are designed to overlap each other and thus extend the barrier against the migration of the germinal cells over the entire equatorial diameter of the capsular bag 46.

According to another embodiment, the invention also relates to an intracapsular implant having a haptic portion of a shape similar to that described in FIGS. 1 to 3 except the diameter of the circle 10 which is adapted to correspond to the equatorial diameter 40 of the crystalline sac 31 The axial thickness of the contact elements, instead of being of the order of 100 microns, is brought to a value of between 300 and 900 microns. The axial thickness of the connecting arms is determined so that the connecting arms have a stiffness in the axial direction greater than their stiffness perpendicular to the optical axis. The invention also relates to a piggy back or phakic type implant having contact elements similar to those described in FIGS. 4 to 6, to their diameter and to their thickness.

Claims (12)

REVENDICATIONS1. An intracrystalline implant having an optical portion (2,36) defining an optical axis (3,37) and adapted to be pressed against a posterior capsule (46) of the crystalline sac (31) and a haptic portion (4, 52) comprising at least a first and a second contact element (13, 13a, 16, 16a, 32, 33) for supporting the equatorial diameter (40) of the crystalline sac (31), the contact elements being coplanar and remote axial of a median plane (38a) of the optical portion (36); the haptic part comprising at least a first connecting arm (34) of the first contact element (32) to the optical part (36) and a second connecting arm (35) of the second contact element (33) to the optical part. , the first and second connecting arms being elastically deformable, characterized in that the connecting arms and / or the contact elements have means for plating (51) the anterior capsule (47) of the crystalline sac (31), said means plating (51) projecting beyond the plane (38) of the contact elements (32, 33), and are capable of keeping the anterior (47) and posterior (46) capsules at a distance. 2. Implant according to claim 1, wherein at least one connecting arm (12, 12a, 34, 34a; 35, 35a) has a corrugation (51) projecting axially from the plane (38) of the contact elements in the direction opposite to the median plane (38a) of the optical portion (36). 3. Implant according to claim 1 or 2, wherein the optical portion (36) has a sharp end of connection between an outer flank (48) and a posterior diopter axially opposed to the contact elements (32, 33). 4. Implant according to one of claims 1 to 3, wherein the first and second connecting arms are symmetrical to each other with respect to a plane of symmetry (8, 41) passing through the optical axis ( 3, 47) and wherein the optical portion (2, 36) is elastically bent with respect to the plane of symmetry (8, 41) of the connecting arms. 5. Implant according to one of claims 1 to 4, wherein the haptic portion (4) comprises two pairs (5, 5a) of U-shaped handles, each U-shaped (6, 6a; 7, 7a) being connected at the optical part (2) only at one end of a U-shaped leg, the other leg of the U forming the contact element (13, 13a; 16, 16a). 6. Implant according to one of claims 1 to 4, wherein the haptic portion (52) comprises at least two first connecting arms (34, 34a) connecting each end of the first contact element (32) to the optical part. and two second connecting arms (35, 35a) of the second contact element (33) to the optical part, each of the first and second connecting arms being elastically deformable, each of the first connecting arms being symmetrical with one of the second arms relative to a plane of symmetry (41) passing through the optical axis (37) and the optical portion (2, 36) being elastically foldable relative to the plane of symmetry (41) of the connecting arms. 7. Implant according to one of claims 1 to 6, wherein all the contact elements (13, 13a, 16, 16a, 32, 33) have a circular arc shape and are arranged in the non-implanted state on a same circle (10, 44), each of the contact elements extending over an angular sector of plating (a, (3) of at least 8 degrees around the optical axis (3, 37). 8. Implant according to claim 7, wherein the arcuate shape of the contact elements is tangent to the circle (44) concentric to the optical axis. 9. Implant according to one of claims 1 to 8, wherein the first and second connecting arms each have at least one flexibility zone (a, b, dg) in a plane perpendicular to the optical axis (3, 37 ), the thickness considered perpendicular to the optical axis, the arms in the zone or zones of flexibility being less than the smallest thickness perpendicular to the optical axis of the contact elements (13, 13a; 16, 16; 33). An implant according to claims 8 and 9 taken together, wherein at least one flexibility zone of a connecting arm is connected to the optical portion (36) at a distance of at least 15% from the distance between the circle (44) and the periphery of the lens of the optical portion (36). 11. Implant according to claim 9 or 10, wherein the connecting arms (34, 34a; 35, 35a) each have a single zone of flexibility (dg) extending over a length greater than 0.6 times the radial distance between the optical part (36) and the corresponding contact element (32, 33) in the non-implanted state. 12. Implant according to claims 4 and 9 taken together, wherein the first and second connecting arms each have a first and a second of said flexibility zones (a, b), distant from each other, the first flexibility zone (a) being further from the plane of symmetry (8, 41) than the second flexibility zone (b), the flexibility zone (b) being arranged in the vicinity of a junction between the contact element (13, 13a, 16, 16a) and the connecting arm (12, 12a, 15, 15a).