EP1732472A2

EP1732472A2 - Improved intraocular lens

Info

Publication number: EP1732472A2
Application number: EP05749103A
Authority: EP
Inventors: Gilles Bos
Original assignee: Xcelens SA
Current assignee: Xcelens SA
Priority date: 2004-04-06
Filing date: 2005-04-04
Publication date: 2006-12-20
Also published as: WO2005099631A2; JP2007531605A; RU2006136883A; FR2868286B1; US20080109077A1; WO2005099631A3; FR2868286A1

Abstract

The invention relates to an improved intraocular lens. According to the invention, the haptic (3) support part (4), elevation view, takes the form of a flat, closed, semi-circular loop having a constant thickness at rest. The proximal end of the loop extends from the distal part of a connecting stalk (5) which extends essentially tangential to the periphery of the optical part (2) and in parallel with the vertical diameter (d1) of said optical part. The aforementioned haptic (3) support part (4) forms an angle of approximately 30° with the horizontal diameter (d2) of the optical part (2).

Description

Advanced intraocular lens

The invention relates to intraocular lenses, and more particularly the problem of centering the lens in the eye, both in the capsular bag and outside said bag. The object of the invention is to give the lens increased refractive stability and predictability, with, for lenses intended for implantation in the capsular bag, a reduction in the risk of cell migration.

It is known that an intraocular lens consists of an optical part, intended in service to be centered on the optical axis of the eye, and of a hiaptic part, connected to the periphery of the optical part whose role is to maintain the centered position of the latter by absorbing the deformations suffered by the eye during the accommodation process and its aging. Because of this essential function, the haptic part of an intraocular lens must meet many constraints: - it must be able to deform in the optical plane,

- it must be practically non-deformable in the optical axis,

- it must not transmit any force likely to deform it to the optical part,

- it must, in service, have the largest possible bearing surfaces,

- it must be foldable for injection into the eye through a small self-suturing incision on the order of 3 mm,

- it must not injure the eye, nor be a factor in post-operative complications.

For the past ten years, numerous solutions have been proposed, and we have seen a great variety of haptic forms appear, both in their support part and in their connection part on the optical part. Thus, US Pat. No. 5,716,403, which relates to a flexible monobloc lens, proposes haptics in open loop with a connecting part of lesser thickness, on the anterior side, than that of the bearing part and an elbow of this part. support above the connection part. However, this lens has the disadvantage of a relatively high rate of opacification of the capsular bag, in comparison with the generation which preceded it. Indeed the design of his haptics concentrates the whole of the deformation on the point of minimum section, but is on the whole too rigid, which does not allow it to adapt to the different conformations of the eyes of the patients and causes a capsular fold promoting cell proliferation in the patients having eyes of small dimensions. On the other hand, the weakening of the axial thickness of the haptic at the level of the connection part causes a risk of imbalance of the two handles and a tilting of the optics which the surgeons characterize by the name of "Z syndrome ". Finally, the large width of the connection part, which extends over an angular sector of around 45 ° at the periphery of the optics, constitutes, due to the absence of angulation of the haptics relative to the optical plane , a springboard for the epithelial cells which intrude between this connecting part and the posterior capsule of the capsular bag and from there can proliferate in the direction of the optical axis.

Patent WO 97/41805, also concerning a flexible monobloc lens, proposes closed-loop haptics with an even larger connection part than that of the lens of US Pat. No. 5,716,403, between 60 ° and 90 ° angular sector, and a weakening of the thickness of the haptics in the connection area. This lens therefore has the same design flaws as the previous lens. The flexible lens described in WO 00/53124 comprises haptics constituted by generally triangular bearing portions connected to the optical part by two arms. The attachment points of said arms to the optical part are spaced from each other, consequently, the connection zone of each haptic to the optical part extends over approximately 90 °. This lens therefore has the drawbacks described above.

It is also known from US 2003/0195622, a flexible lens whose haptic parts are in the form of a split loop in order to constitute clips for attaching the lens to the fixed part of the eye. The implementation of such clamps increases the risk of injuring the eye receiving said lens. The present invention provides a new form of haptic for an intraocular lens, characterized in that its support part, seen in elevation, has the form of a closed semi-circular flattened loop of constant thickness at rest, the part proximal of said loop originating on the distal part of a connecting peduncle oriented substantially tangentially to the periphery of the optical part parallel to the vertical diameter of said optical part, the bearing part of said haptic forming an angle of approximately 30 ° with the horizontal diameter of said optical part. This particular shape of the support part of the haptic, which can be compared to that of an elastic bracelet, has the ability to deform into an infinity of generally circular shapes, which, in its application to a Intraocular lens haptic, provides the assurance of an uncompromising adaptation to the morphology of the patient's eye and a drastic minimization of the projection forces along the optical axis created in the lens during its installation, as a result of the compression of the haptics according to the optical plane of the lens.

According to an advantageous characteristic, the bracelet forming the support part of the haptic has a general shape in an arc of a circle with an opening angle of said arc between 30 ° and 60 °, and preferably 40 °.

The bracelet also has the following advantageous characteristics:

- it has a constant section over its entire length,

its current section is between 0.05 and 0.50 mm, preferably 0.20 mm,

the width and the thickness of the wire or ribbon forming the loop are between 0.2 and 0.8 mm, preferably 0.4 mm,

- The width of the bracelet is between 0.6 and 3 mm, preferably 2 mm and its length is at least twice its width.

Other characteristics and advantages of the invention will emerge from the description which follows of two embodiments of an intraocular lens of a capsular bag, provided with haptics in accordance with the invention. This description, given by way of nonlimiting example, will refer to the appended drawings in which:

FIGS. 1a and 1b are block diagrams of a first embodiment of the invention on a half plan view of an intraocular lens,

FIG. 2 is a diagram showing the principle of the circular deformation of the bracelet loop of the support part of the haptic according to the invention, FIG. 3 a is a diagram illustrating the general characteristics of the support part of the haptic according to the invention,

FIG. 3b is a sectional view along line III-III of FIG. 3a,

FIG. 4 schematically shows the connection to the optical part of an intraocular lens of the support part of the haptic according to the invention,

- Figures 5a and 5b are block diagrams of a second embodiment of the invention on a half plan view of an intraocular lens, 5a being the view of the lens in its compressed form (with inside the eye), 5b being a ve of the lens, before its introduction into the eye, - Figure 6a is a view of the anterior surface of a monobloc lens of a capsular bag produced according to the diagrams of the figures 5a and 5b,

FIG. 6b is a side view of the lens shown in FIG. 6a,

- Figure 6c is a view of the rear face of the lens shown in Figures 6a and 6b, - Figure 7 is a perspective view with partial enlargement of the lens shown in Figures 6a, 6b and 6c,

- Figures 8a and 8b schematically illustrate the projection of an intraocular lens haptic according to the invention before (Figure 8a) and after (Figure 8b) its placement in the capsular bag. - Figure 8c is a comparative diagram showing the behavior in the capsular bag of a lens of the prior art and of the lens according to the invention at the connection of the haptic part on the optical part.

FIG. 1a shows a schematic half view of the anterior face of an intraocular lens 1 with its generally circular optical part 2, and its haptic part 3 which breaks down into a support part 4 and a part connection 5. The circular line 6 represents the inscribed circle defined by the lens 1 at rest. In FIG. 1b, only the optical part 2, the support part 4 of the haptic 3 are shown, the inscribed circle 6 of the lens at rest and the inscribed circle 7 of the lens in the service position. It can be seen in these figures that the connection part 5 forms a peduncle which is connected to the periphery of the optical part 2 over a relatively small angular distance relative to the circumference of the implant. Preferably this angular distance will be of the order of 15 ° to 20 °. It can also be seen that the peduncle 5 extends in a general direction practically parallel to the vertical diameter dl of the optical part 2 and that its outer edge 5 'is substantially tangential to the periphery of the optical part 2.

On the distal part of the peduncle 5 is born the support part 4 of the haptic 3, in a general direction d2 which forms an angle α of about 30 ° with the horizontal diameter d3 of the optical part 2. The part d support 4 has the shape of a closed semi-circular flattened loop of constant thickness at rest, similar to that of an elastic bracelet. It can be seen in FIG. 1b that the arc formed by the loop 4 extends over an angular distance β of approximately 40 °.

As indicated previously, this particular form of the support part 4 of the haptic 3 has the property of deforming regularly according to an infinity of co-planar loops to the initial loop around the median axis ml of the loop, as well as l 'illustrates Figure 2.

Thanks to these provisions, it is ensured that the compressive forces which are exerted on the haptic of the lens after it has been placed in the eye are concentrated on the median axis ml of the loop 4 parallel to the optical plane of the lens which at the same time allows the support part 4 to marry over a great length and without roughness the outline of its housing and to minimize the projection forces of the optical part 2 on the optical axis.

In practice, for an intraocular lens whose overall diameter at rest (reference 6 in FIG. 1 a) is of the order of 13 mm, and the overall diameter in service (reference 7 in FIG. 1 b) is of the order of 10.5 mm, the following dimensions will be adopted (cf. FIG. 3), taking as a reference a plane perpendicular to the optical axis:. height 8 of the buckle: from 0.6 to 3 mm, preferably 1.4 mm,. length 9 of the loop: from 1.2 to 6 mm, preferably 5 mm, . cross-sectional area 10 of the wire or ribbon constituting the loop: from 0.05 to 0.5 mm ² , preferably 0.2 mm ² ,. width 11 of the wire or ribbon constituting the loop: from 0.2 to 0.8 mm, preferably 0.4 mm,. thickness 12 of the wire or ribbon constituting the loop: from 0.2 to 0.8 mm, preferably 0.4 mm,. initial radius of curvature R of the loop: 4.5 to 6 mm, preferably 5.75 mm.

Preferably, a section of ribbon of thickness 12 equal to or greater than its width 11 will be adopted in order to favor the homogeneous deformation of the two superimposed strands of the loop 4 and to avoid inducing torsional components detrimental to the stability of the haptics.

The peduncle 5 will have practically the same thickness as that of the wire or ribbon constituting the loop, that is to say from 0.2 to 0.8 mm and preferably 0.4 mm, while its height relative to the circumference of the optical part will be on the order of 0.4 to 2 mm and preferably 0.6 mm. These provisions ensure that the peduncle 5 does not significantly interfere with the homogeneous deformation of the support part 4.

In the case of an intraocular lens of a capsular bag, it is recommended to give the haptic part, seen in profile in the optical plane, an angulation with respect to said plane so as to create during compression of the haptics a displacement force of the optical part in the direction of the vitreous along the optical axis, which has the effect of pressing the posterior diopter of the optical part against the rear wall of the lens bag. As can be seen in FIG. 4, the haptic part of the intraocular lens according to the invention has such an angulation at the level of its peduncle 5, while its bearing part 4 is parallel to the optical plane. According to an advantageous characteristic of the invention, the peduncle 5 of the haptic part is connected directly to the periphery of the anterior diopter of the optical part at an angle of about 15 ° relative to the optical plane, which determines a projection towards the front of the support part 4 at rest of about 0.6mm relative to the edge limiting the circumference of the posterior diopter of the optical part and ensures that this projection will not exceed a value between 0.9 and 1 mm after the placement of the lens in the capsular bag.

Thus, by the combination of the shape of a flat elastic bracelet of the support part of the haptic, of its inclination at an angle of about 30 ° on its connecting peduncle and of the implantation of said peduncle on the periphery of the anterior diopter of the optical part with an angulation of about 15 °, the intraocular lens according to the invention provides the following performances:

- a bending of the support part contained in a plane perpendicular to the optical axis, with a limited projection component, - a bending of the very homogeneous support part and in perfect conformation with the compression environment: this support part shows an inversion behavior of the main window (between the two strands of the bracelet) during its bending, which gives it the capacity not only to adapt to the dimensions of the eye which receives it, but also not to generate capsular folds, - a projection induced by the compression of the haptics limited: a distance greater than 0.9 mm between the edge of the posterior diopter of the optic relative to the posterior plane of the support parts of the haptic makes it possible to obtain a force of projection ensuring the contact of the posterior diopter with the posterior capsule,

a sharp-angle contact of the peripheral edge of the posterior diopter with the said posterior capsule, amplified by the production of an indentation of this optic in the said posterior capsule, indentation linked in turn to the force of projection, even linked to the architecture of Pangulation and the presence of this sharp edge,

- an absence of “Z syndrome” or decentering of the optical part, as well as a prevention of cell proliferation responsible for the capsular popacification.

Figures 5a and 5b show an advantageous alternative embodiment of a capsular bag implant according to the invention. We see in these figures that we added under the support part 4 of the haptic 3 and near its proximal end, substantially parallel to the peduncle 5, a strut 13 intended to improve the homogeneity of deformation of the support part 4. This strut 13, by its position avoids any bending of the support part 4 which would not be due to a deformation of the latter as well as any bending of the peduncle 5.

Figures 6 to 8 illustrate a preferred embodiment of an intraocular lens according to the invention. In these figures, the reference numbers refer to the explanations given in relation to the previous figures. We find in Figures 6a, 6b and 6c, the same essential components as in Figures 5a and 5b namely: the optical part 2, circular and biconvex, the connecting peduncle 5 implanted on the periphery of the anterior diopter with an angulation approximately 15 °, the support part 4 in the form of a semi-circular bracelet attached to the peduncle 5 in a general direction forming an angle of approximately 30 ° with a plane passing through the horizontal diameter of the optical part, and the strut 13 substantially parallel to the peduncle 5 and disposed under the proximal end of the bracelet 4.

The lens 1 has a particular configuration of the periphery of its optical part, intended to reinforce the prevention against cell proliferation. Indeed, the diameter of the posterior diopter 14 is smaller than that of the body 15 and the connection of the edge 16 thus formed with the peripheral edge 17 of the optics is made by a concave fillet 19 which defines a second edge 18 with said song. Said edge 18 also extends over the entire periphery of the edge 17, including in the connection portions of the peduncles 5 and the struts 13. In addition, the implantation of the peduncles 5 and the struts 13, with their angulation of approximately 15 °, is made straddling the anterior edge between the anterior diopter 15 and the edge 18 of the edge 17, so that, in this connection zone, the posterior face of the peduncles 5 and of the legs of force 13 is in the extension of the concave leave 19. The purpose of this arrangement is to provide a smooth transition from the indentation of the posterior part of the implant into the capsular bag by orienting the tension forces which are exerted on the bag parallel to the rear face of the peduncles and the struts, which has the effect of preventing the formation of folds on the edge 18 as illustrated diagrammatically in FIG. 8c. In this figure, in the right part is represented a section of the connection without leave 19 and in the left part a similar section with leave 19. We see that in the absence of leave, under the effect of a significant gradient of forces pressure of the vitreous on the posterior diopter of optics (arrows 20a), the capsule has a significant inflection which causes a result of the tension forces (arrow 20b) oriented not parallel to the posterior surface of the peduncle 5. In the presence of the fillet 19, the pressure forces of the vitreous (arrows 20a ') gradually decrease from the edge 16 of the diopter posterior to the edge 18, so that the capsule marries the concavity of the leave 19 and that the result of the tension forces (arrow 20b') is oriented parallel to the back side of peduncle 5.

Figures 8a and 8b schematically shows the behavior of the lens according to the invention under the effect of the compression of the support part of its haptic part when it is placed in the capsular bag. The force symbolized by the arrow 21 causes a projection of the optical part towards the rear of the order of 0.3 mm for a reduction in the overall diameter of the lens from 13 mm to 10.5 mm. This projection has the effect of pressing the posterior diopter against the wall of the capsular bag into which it indents thanks to the edge 16 by closely matching the leave 19. This provides an effective barrier against the progression of the epithelial cells towards the wall of the capsular bag.

Preferably the radius of curvature of the fillet 19 is of the order of 0.2 to 0.6 mm and its maximum depth is 0.1 mm.

The embodiments described above relate to an intraocular lens of a capsular bag. However, the invention encompasses all types of intraocular lenses, whether implanted in or out of the capsular bag.

Claims

1.- Intraocular lens characterized in that the support part (4) of its haptic part (3), seen in elevation, has the shape of a flattened semi-circular closed loop of constant thickness at rest, the proximal part of said loop originating on the distal part of a connecting peduncle (5) oriented substantially tangentially to the periphery of the optical part (2) parallel to the vertical diameter (dl) of said optical part, the part of support (4) of said haptic part (3) forming an angle of approximately 30° with the horizontal diameter (d2) of said optical part (2).

2.- Intraocular lens according to claim 1 characterized in that the support part (4) of the haptic part (3) has a general arc shape with an opening angle of said arc between 30° and 60°, and preferably 40°.

3.- Intraocular lens according to claim 1 or 2 characterized in that the support part (4) of the haptic part (2) is of constant section over its entire length.

4.- Intraocular lens according to any one of claims 1 to 3 characterized in that the current section of the wire or ribbon forming the loop of the support part (4) is between 0.05 and 0, 50 mm ² , preferably 0.20 mm ² .

5.- Intraocular lens according to any one of claims 1 to 4 characterized in that the width (11) and the thickness (12) of the wire or ribbon forming the loop of the support part (4) of the haptic part (3) are between 0.2 and 0.8 mm, preferably 0.4 mm.

6.- Intraocular lens according to claim 5 characterized in that the thickness (12) of the wire or ribbon forming the loop of the support part (4) of the haptic part (3) is at least equal or is greater than its width (11).

1.- Intraocular lens according to any one of claims 1 to 6 characterized in that the height (8) of the support part (4) of its haptic part (3) is between 0.6 and 3 mm, preferably 1.4 mm and in that its length (9) is at least equal to twice its width.

8.- Intraocular lens according to any one of claims 1 to 7 characterized in that the connection part (5) of the support part (4) on the optical part (2) extends, seen in plan, in a general direction practically parallel to the vertical diameter (dl) of the optical part (2) and that its external edge (5') is substantially tangential to the periphery of the part optical (2).

9.- Intraocular lens according to claim 8 characterized in that the connecting part (5) is connected to the periphery of the optical part (2) over a relatively small angular distance relative to the circumference of the lens, preferably around 15° to 20°.

10- Intraocular lens according to claim 8 or 9 characterized in that the connecting part (5) is connected to the periphery of the optical part (2) forming with the latter an angle of approximately 15° relative to optically.

I - Intraocular lens according to any one of claims 8 to 10 characterized in that it comprises a strut (13) disposed under the support part (4) of its haptic part (3), to proximity to the proximal end of said support part (4).

12.- Intraocular lens according to claim 11 characterized in that the strut (13) is arranged substantially parallel to the connecting part (5).

13.- Intraocular lens according to any one of claims 8 to 10 characterized in that the diameter of the posterior diopter (14) of its optical part (2) is smaller than the diameter of the body (15) and in what the peripheral edge (16) of the posterior diopter (14) is connected to the peripheral edge (17) of the optical part (2) by a concave fillet (19).

14.- Intraocular lens according to claim 13 characterized in that the implantation of the connecting part (5) and/or the strut (13) on the periphery of the optical part (2) is carried out astride the edge of the anterior diopter (15) so that the rear face of said connection part (5) and/or strut (13) is in the extension of the concave fillet (19).

15.- Intraocular lens according to claim 13 or 14 characterized in that the radius of curvature of the fillet 19 is of the order of 0.2 to 0.6 mm and its maximum depth is 0.1 mm .