FR2572927A1 - INTRAOCULAR IMPLANT COMPRISING A LENS-FORMING BODY AND A RETENTION DEVICE FOR THE SAME - Google Patents

Abstract

IN AN INTRAOCULAR IMPLANT 10 OF THE TYPE INCLUDING A LENS AND AT LEAST ONE FLEXIBLE RETAINING FOOT 16 THE FREE END 20 OF THE FOOT OR FEET HAS A MEANS 22 ENABLING THEM IN A SUPPLEMENTARY ENGAGEMENT 30 PROVIDED FOR IN THE PERIPHERAL PART 14 OF THE LENS, SO THAT, WITH THE FOOT BEING ENGAGED IN THIS MEANS, THE LATERAL DIMENSION OF THE IMPLANT DOES NOT EXCEED SUBSTANTIALLY THAT OF THE PERIPHERAL PART ONLY, SO FACILITATING THE INSERTION OF THE IMPLANT IN THE EYE THROUGH AN INCISION. IN A PREFERRED EMBODIMENT OF THE INVENTION THE PERIPHERAL PART OF THE LENS BODY HAS A RIB 18 protruding upwards and against which foot 16 is supported by bending around the body of the lens, in order to distribute the flexion MAJOR PART OF THE FOOT.

Description

Intraocular implant comprising a lens body

  and a retainer therefor.

  Intraocular lenses used as ocular implants are well known in the state of the art. The insertion of such a lens requires that an incision is made in the eye to allow removal of the

  natural lens that constitutes the lens and

  rer the implant, which is formed of a biological material-

  inert and transparent such as polymethyl methacrylate. The length of the necessary incision depends on the total width of the lens to be inserted. Any reduction in the width of the implant would reduce the length of the incision, which is desirable because the smaller the incision, the less difficult the recovery and postoperative healing period for the patient. Although it is considered desirable to provide such implants with at least three retaining feet to provide secure support and centering, many such implants have only two flexible retaining feet since implants having two feet can have to pass through a narrower incision than that necessary for an implant with three or more

large number of feet.

  Another problem posed by such devices is that even if they have only two feet insertion of the device into the eye is difficult since the first foot introduced into the incision must be flexed so as to be brought to the contact with the eye tissue to allow the lens to be inserted deep enough for the second foot to enter the incision and take place in the appropriate eye cavity. An intraocular implant is made of a material

  plastic suitable for this purpose such as polymetha-

  methyl crylate and comprises, on the one hand, a lens body comprising a central part forming a lens and a peripheral part which, serving as a support for the lens, is arranged around the latter and, on the other hand, at least a flexible retaining foot extending from the peripheral part serving to support the lens. In the free state, that is to say not deformed, the flexible retaining foot extends around at least a portion of the peripheral part and this at a certain radial distance from it, to end with a free end. The free end is provided with an engagement means and the peripheral part of the lens body is provided with complementary engagement means intended to receive the free end of the foot so that it can be there. releasably engage. The manner in which the complementary engagement means provided in the lens body are arranged on the circumference thereof and the dimensions of the foot are such as the foot, being bent inwardly to allow its free end to engage in the corresponding engagement means, extends along the outer edge of the peripheral part, so that the total width of the implant, when the latter is ready to be inserted into the eye, is not greater than the width of the body of

lens alone.

  In a preferred embodiment of the invention

  tion a peripheral part of the lens body is provided with an element projecting upwards and which, serving as lateral support for the foot, is arranged so that, in

  being bent around the lens body in order to subject-

  pulling its free end at the latter, the foot bears against the lateral support element which thus determines the degree to which the foot is flexed inwardly so as to distribute the deflection along an important part of the foot and avoid excessive flexing at

the root of the foot.

  Therefore, an implant can be provided with any desired number of retaining feet and with means for securing each foot to the lens body, so that the total width of the implant is not

  not increased by the presence of the feet.

  The invention is described in more detail below with the aid of the appended drawings in which:

  Figure 1 is a top view of a shaped implant

  mant intraocular lens as it is in the manufactured state, the flexible retaining feet being free,

that is to say, not deformed; -

  Figure 2 is a side elevational view of the implant of Figure 1; Figure 3 is a perspective view of the implant of Figure 1; Figure 4 is a top plan view of the implant of Figure 1, the flexible retaining feet being engaged in the lens body so that the implant is ready to be introduced into the eye; Figure 5 is a side elevational view of the device of Figure 4; Figure 6 is a view of the implant of Figure 4, it having been introduced into the eye and the feet having then been released; Figure 7 is a top plan view of another embodiment of the implant according to the invention, the feet being in the free state, that is to say not deformed; Figure 8 is a view of the device of Figure 7, the flexible feet having been engaged in the lens body for insertion of the device into the eye. In Figures 1 to 6 is illustrated a first embodiment of the invention which consists of an implant 10 comprising, on the one hand, a lens body which comprises a central part 12 forming the lens proper and a peripheral part 14 forming support and, on the other hand, a pair of flexible retaining feet 16.

  The central portion 12 forming a lens can present

  ter, in cross-section, any shape desired in order to obtain

  set the desired lens effect. The peripheral part 14 extends around the entire periphery of the lens 12 and is provided with a rib 18 projecting upwards

on the peripheral part.

  Each retaining foot 16 is integral with the part

  peripheral tie and extends therefrom around the lens body, at a certain radial distance therefrom, ending in a free end 20 which

  has a laterally extended zone 22 across lacquer

  an opening 24 extends there. The feet 16 have a proximal part 26 which narrows from the root (junction with the peripheral part) to a place represented in FIG. 1 by the point "A", and a distal portion 28 of substantially uniform width extending from point "A" to the area of greatest extent located at the free end. This configuration of the retaining foot provides a portion of uniform thickness for placing the implant in an eye cavity, while allowing the flexing force to be distributed along the foot in order to reduce the risk of the foot breaking

the root 26.

  The radius of curvature of the foot gradually increases from the root to the area of greatest extent, the part 29 immediately contiguous to the area of greatest extent being folded inwards for a purpose.

describe further.

  The rib 18 has a pair of slots 30 extending through it in a substantially radial direction, each slot 30 being suitably arranged to receive the free end of a foot so that the area of greatest extent 22 is placed inside the rib and the adjacent part of the foot is placed in the slot (see

figure 4).

  In a preferred embodiment of the invention

  tion, when the free ends 20 are thus engaged in the slots, the rest of the foot is curved around the outer edge of the peripheral part inside a circle concentric with this outer edge, as illustrated in Figure 4, which represents the implant ready to be inserted into the eye, and is held in this position by

means yet to describe.

  As illustrated in FIG. 4, when the feet are engaged in the peripheral part, the implant has

  a width that does not exceed that of the periphery

  alone, so the use of the implant requires only a lengthy surgical incision

minimal.

  The implant is supplied to the surgeon in the represented state.

  felt in Figure 1, the feet being neither deformed nor subjected to stresses. In view of the implantation, the feet 16 are bent inwards and engaged with their part 29, contiguous to the zone of greatest extent 22, in the slots 30. The tendency of the bent feet to resume their initial shape will have the effect of pulling the area of greatest extent so as to bring it intimately into contact with the rib on both sides of the slit so that the feet are retained in the bent state. The implant having been inserted through the incision in the eye, the ends of larger extent 22 can be pulled out of the slots 30 by being lifted by means of a suitable tool so that they can resiliently resume their former shape in s spreading towards

  outside in the surrounding eye cavity.

  Of course, some surgeons may prefer to secure the end of only one of the feet to the body

  lens before inserting the implant.

  In the embodiment of Figures 1 & 6 the rib 18 is divided into two parts by slots 30, each part having an outer surface 32 which extends more and more radially inwards as it approaches the slit, and each surface 32 is arranged in such a way that the foot, by bending inwards to come into contact with the rib, bears against the surface 32, thus reducing the bending force exerted on the root of the foot at

  where it is connected to the lens body.

  The contact of the foot with the surface 32 also determines the degree of flexion of the distal part of the foot and provides it with support in order to prevent the foot from being damaged during its handling before and during

  introduction of the implant into the eye.

  In many types of implants, the retaining feet are inclined slightly backwards relative to the plane of the lens so as to maintain the latter in a desired position relative to certain parts of the structure of the eye. In such a case, the feet 16 must be slightly bent forward so that they can be bent around the rib and engaged in the slot 30. Consequently, the feet are supported, so as to be prevented from bending downwards, by the peripheral part 14 located just outside the rib, so that they are not likely to tend to

release from the slot.

  In Figures 7 and 8 is shown another

  embodiment of an implant having the characteristics

  invention. In this embodiment, an implant 40 comprises, on the one hand, a lens body

  comprising a central part 42 forming a clean lens

  ment said and a peripheral part 44 and, on the other hand, three elastic retaining feet 46 extending from the peripheral part around the lens body at a certain distance therefrom. The peripheral part 44 has three rib segments 48 in each of which is formed a transverse slot 50, which is arranged circumferentially so as to receive

  the free end of a foot, so that the lateral area-

  extended 52 of this end is retained on the inner side of the rib, as described above about

  the embodiment of Figures 1 to 6.

  When the three feet 46 are bent inward

  inside so as to curve around the outer edge of the peripheral part and the end of the feet is placed in the respective slot 60, so that the area of greatest extent is retained on the inside of the rib , the total width of the implant is not greater than that of the lens body alone, so that the presence of three retaining feet

  on the lens body in no way requires an inci-

  longer surgical session than when

expected only two feet.

  In each of the two embodiments, the ribs (18 or 48) are on the front side of the implant so that the feet are secured to the front side of the implant. This has the advantage not only of facilitating the release of the feet from the slots after the implant has been inserted into the eye, but also of preventing the implant from being inserted into the eye upside down, it i.e. so that the rear surface of the lens is on the side

  exterior, which is notoriously happening.

  Although in the embodiments shown

  tees means are provided to subject each foot to the lens body, it goes without saying that in some cases it

  may be expected to secure only one foot. For example-

  ple, if an implant of the type shown in Figures 1 to 6

  is used, the surgeon may find it necessary to

  throw only one foot to the lens body before.

  der to the insertion of the implant. Consequently, the device of FIGS. 1 to 6 may, under certain conditions of use, only comprise means for securing a single foot to the lens body. Similarly, in the case of the embodiment of Figures 7 and 8 it may be necessary to provide only the subjugation

  one or two feet to the lens body.

  Means of securing the foot to the body of

  tille are represented as being constituted by a larger area at the end of the foot, and a slit

  provided in the peripheral rib to receive the end

  foot mite. It goes without saying, however, that other means of securing the foot to the lens body may be

  provided without departing from the scope of the invention.

  Although in the embodiments of the invention,

  tion shown the implant is made in one piece of the same material, the elastic feet can if necessary be made separately and then connected to the body of

  lens by any suitable means.

  Since various other modifications within the reach of ordinary skill in the art can be made to the embodiments shown and described in detail,

  these should only be considered as examples

  ples having no limiting character.

Claims (9)

  1 - Intraocular implant comprising a body of   lens and a retainer therefor, the-   which device comprises at least one flexible retaining foot (16; 46) which in the non-deformed state extends from a root zone, connected to the lens body, and ends with a free end (20; 50),   characterized in that the free end has a shoulder   located on the side opposite this end and in that the lens body has an engaging means (30;) intended to receive the shoulder so that the latter can engage therein in a removable manner, said means of engagement being disposed circumferentially such that when the shoulder is retained by the engagement means (30; 60), the remainder of the foot (16; 46) is located   around the periphery of the lens body.   2 - Implant according to claim 1, wherein three flexible feet (46) are substantially arranged in a regularly spaced manner around the periphery of the lens body, and engagement means (60) are   provided in the lens body to allow the   mite (50) of at least one of the feet (46) to be engaged therein   and detachably retained, characterized in that the-   said engagement means are arranged circumferentially-   Lement in such a way that substantially the whole of a foot retained by its engagement means is inside a circle having the center of the lens (42) for center and a diameter which does not exceed the diameter of lens body.   3 - Implant according to claim 1, characterized in that the end (20; 50) of the foot (16; 46) has a laterally extended zone (22; 52) which forms said shoulder and in that the lens body comprises at its periphery a rib (18; 48) projecting upwards, which rib has a transverse slot 30 .; 60) arranged to receive the part of the foot contiguous to the area of greatest extent (22; 52) so that it is retained on the inside of the rib   so as to be engaged therein in a removable manner.   4 - Implant according to claim 1, characterized in that the foot (16) is integral with the lens body   and has a proximal part (26), which retracts   cementing from the root to a narrower middle part, and a distal part (28) of a substantially constant width which extends beyond the middle part, thus allowing the stresses exerted in the foot (16 ) as a result of the displacement of the distal part   (28) to be distributed along the proximal part (26).   - Implant according to claim 3, characterized in that the foot (16) is, in the undeformed state,   tilted at a slight angle to an extended plane   dant through the lens perpendicular to the axis thereof and in that the inner surface of the rib (18), contiguous to the slot, makes an angle with said plane so as to extend parallel to the forming part shoulder of the foot.   6 - Implant according to claim 3, characterized in that the rib (18) is arranged on the peripheral part (14) so that the foot (16), being bent inward to come into contact with the rib (18), bear against the outer surface (32) of the latter so that its curvature is well determined. 7 - Intraocular implant, characterized in that it   includes a lens body, having a central portion   trale (12; 42) forming the lens itself and a peripheral part (14; 44) serving as a support for the lens, and a device intended to retain the lens body and comprising at least one flexible foot (16; 46)   which, in the undeformed state, extends substantially tangential-   from the peripheral part forming a support, then radially outwards in the form of a spiral to a terminal part (22; 52) which is turned inwards and has an engaging shoulder, means (30; 60) being further provided on the lens body to receive said shoulder to allow the inwardly facing end portion to be held engaged with these means.   8 - Implant according to claim 7, characterized in that the engagement means comprise a rib (18; 48) and a slot (30; 60) extending approximately transversely through the rib, the slot being dimensioned and arranged to receive the end part (22; 52) facing inwards, when the foot (16; 46) is bent around the peripheral part (14; 44), and to retain the foot in the bent state, in such a way that substantially the entire foot, thus being brought into contact with the rib, is located inside the   outer circumference of the peripheral part.   9 - Implant according to claim 8, characterized in that a rib portion (18; 48) is disposed on the peripheral portion (14; 44) so that the foot (16; 46) bears against the exterior surface (32) of the rib when bent inward in   direction of the engagement position.   - Intraocular implant comprising a lens body and a retaining device for the latter, which device comprises at least one flexible retaining foot (16; 46) which, in the undeformed state, extends from a root zone connected to the lens body to a distal part (28) located at a certain distance from the body and terminated by a free end (20; 50), characterized in that the distal part   (28) and the lens body have cooperating means   rant between them to allow the distal part (28) to be   be removably secured to the lens body.   11 - Implant according to claim 10, characterized   in that the engagement means include a   tie provided on the free end (20; 50) of the foot (16; 46) and a part provided on the lens body and arranged so that when the free end (20;) of the foot (16 ; 46) is subject to the latter, the foot   lies flexed around the periphery of the body of len-   tille. 12 - Intraocular implant comprising a body of   lens and a retainer therefor, the-   which device includes at least one flexible retaining foot   ble (16; 46) which, in the undeformed state, extends from a root zone connected to the lens body to a distal part (28) located at a certain distance from the body and ending in a free end (20;), characterized in that the distal part (28) and the lens body have means cooperating with each other   to allow the foot (16; 46) to be flexed circumferen-   tily around the lens body and to the distal part to be subject thereto, a means (18; 48) - serving as support for the foot (16; 46) being further disposed on the periphery of the lens body, between the root area of the foot and the free end thereof, so that the foot (16; 46), being flexed around the lens body to allow the distal portion to be secured thereto , take support against the means (18; 48) serving as a support in order to thereby determine the degree of deflection of the foot and to allow the deflection stresses to be distributed over a major part of the foot so as to avoid sagging   excessive at the root of it.   13 - Implant according to claim 12, characterized in that the means (18; 48) serving to support the foot   consists of a peripheral wall extending circumferen-   partially around a part of the lens body.