WO2008080464A1

WO2008080464A1 - Intraocular lens

Info

Publication number: WO2008080464A1
Application number: PCT/EP2007/010242
Authority: WO
Inventors: Arthur Messner; Claudia Hoffmann
Original assignee: Dr. Schmidt Intraocularlinsen Gmbh
Priority date: 2006-12-22
Filing date: 2007-11-26
Publication date: 2008-07-10

Abstract

The invention relates to an intraocular lens (1) with an anterior optic surface (6) and a posterior optic surface (7), which is to be implanted into the anterior chamber of an eye. To correct aberrations, at least one of the optic surfaces (6, 7) is aspherically designed.

Description

intraocular lens

The invention relates to an intraocular lens for implantation in the anterior chamber of an eye, in particular of a human eye.

Intraocular lenses for implantation in the anterior chamber of an eye have long been known and are implanted into the human eye either after removal of the natural lens as a substitute for or in addition to the natural lens for correcting ametropia. Intraocular lenses, which are also implanted without removal of the natural lens, are also referred to as phakic intraocular lenses. In the development and application of such intraocular lenses, there is a continuing need to improve the tolerability and imaging characteristics of implanted intraocular lenses.

A known disadvantage is that aberrations of conventional intraocular lenses reduce the imaging quality of the entire optical system of the eye

The invention has for its object to further develop an intraocular lens for implantation into the anterior chamber of an eye, in which the introduction of additional aberrations in the eye, through the intraocular lens, is avoided.

This object is solved by the features of claim 1. The essence of the invention is that at least one of the optical surfaces is aspherical. Due to the asphericity otherwise unavoidable aberrations of the intraocular lens are corrected. The resulting aberration-free intraocular lens can enter the anterior chamber of an eye be implanted without inducing aberrations in the optical system. By means of the haptic arms, the optics are easy and well-tolerated to the iris of the eye attachable.

Further advantageous embodiments of the invention will become apparent from the dependent claims.

Additional features and details of the invention will become apparent from the description of several embodiments with reference to the drawings. Show it:

1 is an anterior view of an intraocular lens,

2 is a side view of the intraocular lens in Fig. 1,

3 shows a cross section through the intraocular lens along the section line III-III in Fig. 1,

Fig. 4 is an enlarged detail of the intraocular lens in Fig. 3, and

5 shows a cross section through the intraocular lens along the section line V-V in Fig. 1 with a simplified representation of the haptic arms,

6 is a view of another intraocular lens,

7 is a view of a third intraocular lens,

Fig. 8 is an anterior view of another intraocular lens and 9 is a side view of the intraocular lens in Fig. 8.

In the following, a first exemplary embodiment of an intraocular lens will be described with reference to FIGS. An intraocular lens 1 is designed in several parts and has a central optic 2 and haptics 3 attached thereto. The optics 2 has in the center an optical axis 4 and a perpendicular to the optical axis 4 through the lens 2 extending lens plane fifth

The optic 2 comprises an anterior optic surface 6 facing the cornea of the eye in the implanted state and a posterior optic surface 7 opposite the lens plane 5 and facing the iris of the eye in the anterior optic surface 6. The optic surfaces 6, 7 are substantially transversely to the optical axis 4 and are continuous, that is, the optical surfaces 6, 7 have no Frel tern stages due to the continuous course. Preferably, the surfaces 6, 7 are continuously curved. Between the optical surfaces 6, 7 extends a concentric and parallel to the optical axis 4 extending annular edge surface 8. The edge surface 8 is in the direction of the anterior optic surface 6 of a circular anterior optic edge 9 and delimited in the direction of the posterior optic surface 7 by a circular posterior optic edge 10.

The anterior optical edge 9 has a sharp-edged design and extends along a partial circular arc with a radius R 1 of less than 100 μm, in particular less than 50 μm, and in particular less than 10 μm. The posterior optic edge 10 is also sharp-edged and extends along a partial arc with a radius R2 - A -

less than 100 μm, in particular less than 50 μm, and in particular less than 10 μm.

The anterior optic surface 6 is convexly curved relative to the lens plane 5 and has in its entire region a local radius of curvature R _A in the range of 3 mm to 90 mm, in particular 4 mm to 80 mm, and in particular 5 mm to 70 mm. Alternatively, the anterior optic surface 6 may also be concavely curved relative to the lens plane 5 and have a local radius of curvature R _A in said regions. The posterior optic surface 7 is concavely curved relative to the lens plane 5 and has in its entire region a local radius of curvature Rp in the range of 4 mm to 20 mm, in particular 6 mm to 16 mm, and in particular 8 mm to 12 mm up.

At least one of the optical surfaces 6, 7 is formed in such an aspherical manner that the intraocular lens 1 is aberration-free. Aspherical in this context is understood to mean a surface geometry which deviates from the spherical one, ie. at least one of the optical surfaces 6, 7 can not be described by a spherical surface cutout. The optical surfaces 6, 7 are formed rotationally symmetrical to the optical axis 4. The shape of the optics surfaces 6, 7 can be described generally by the following equation:

Here, z (h) denotes the arrow height, that is, the distance between a point X on the optical surface 6, 7 and a fixed reference point P on the optical axis 4, r ₀ the central radius, ie the radius of curvature of the optical surface 6, 7 at the intersection with the optical axis 4, h the incidence height, ie the radial distance of the point X on the optical surface 6, 7 to the optical axis 4 and Q the so-called Konic factor, a measure of the asphericity. The higher order terms are determined by the deformation coefficients a _n . If Q = O, the equation describes a spherical surface except for the higher order toms. For the Konic factor Q of the at least one aspheric optical surface 6, 7: Q ≠ 0 and -10 <Q <10, in particular -5 <Q <5, in particular -1 <Q <1.

The optic 2 is made in one piece from an optical material, wherein for example silicone with a refractive index of approximately 1.43 is used as the optic material. Alternatively, a hydrophilic acrylate having a refractive index of 1.46 or a high refractive index optical material having a refractive index of greater than 1.5 can be used as the optical material.

The two haptics 3 attached to the optic 2 extend radially outwards and are arranged opposite one another relative to the optical axis 4. Alternatively, it is also possible to provide a different number of haptics, as long as they are evenly distributed over the circumference of the optics. The haptics 3 are identical and attached to the optics 2, so that only one haptic 3 is described in detail below.

The integrally formed haptic 3 has two haptic arms 12 bounding an entrapment gap 11 and a haptic stirrup 13 connecting the haptic arms 12. The haptic strap 13 includes a received in an optical recess 14 and the optical material completely The attachment portion 15 extends centrally concentric with the optical axis 4 and is angled endwise such that it is adjacent to the connecting portions 16 and correspondingly radially outwardly thereof runs. The haptic bracket 13 breaks through the edge surface 8 - viewed circumferentially - with an angle α of approximately 90 °. The haptic strap 13 extends substantially tangentially and flush to the posterior optic surface 7 and extends to an anterior haptic edge 17 and a posterior haptic edge 18. The connecting portions 16 close - viewed along the optical axis 4 - With the edge surface 8 a the local radius of curvature R _{P of} the posterior optic surface 7 in the region of the posterior optic edge 10 adapted angle ß a. The anterior haptic edge 17 and the posterior haptic edge 18 run substantially parallel to the edge surface 8, wherein the anterior haptic edge 17 due to the inclination of the Haptik- strap 13 relative to the lens plane 5 a greater distance to the optical axis 4 as the posterior haptic edge 18 has.

The attachment section 15 has a central cross-section in the form of a parallelogram, wherein an upper and a lower side wall parallel to the edge surface 8, as shown in FIGS. 3 and 4 show. In the area of the edge surface 8, the cross section of the attachment portion 15 increases such that along the edge surface 8 a width B _{B of} the attachment portion 15 corresponds to a width B _{v of} the connection portions 16. Viewed along the optical axis 4, the connection portions 16 have a depth T _v that is greater compared to a depth T _{B of} the attachment portion 15, so that the connection portions 16 face toward the posterior optic edge 10 form extending projection 19 which rests against the edge surface 8, as Fig. 5 shows.

Between the bonding portion 15 of the haptic strap 13 and the optic material is disposed a coating 20 which is opaque to light of the visible spectrum. The coating 20 has a thickness D of at least 0.5 μm, in particular of at least 1 μm, and in particular of at least 5 μm. As an alternative to the coating, the surface of the bonding section 15 can be roughened.

Starting from the anterior haptic edges 17 and the posterior hap- tic edges 18, the haptic arms 12 extend parallel to the lens plane 5. The haptic arms 12 initially extend radially from the haptic edges 17, 18 on the outside and also bend so that they are substantially parallel to the edge surface 8 and to each other. At their free ends, the haptic arms 12 have perpendicular to the lens plane 5 extending end faces 21, which limit the pinching gap 11 laterally.

For attachment of the intraocular lens 1 to the iris, the haptics 3 at the end faces 21 have an average roughness depth of at least 5 μm, in particular of at least 10 μm, and in particular of at least 20 μm. The mean roughness of the other haptic F laugh is less than 4 microns, especially less than 3 microns, and in particular less than 2.5 microns.

The edge surface 8 of the optic 2, the connecting portions 16 of the haptic strap 13 and the haptic arms 12 essentially define a haptic recess 22. The haptic recess 22 is in engagement with the pinching gap 11 Connection. The haptics 3 are integrally molded from a haptic material, wherein as a haptic material PMMA is used in particular. The haptic material has a first modulus of elasticity E _H and the optical material has a second modulus of elasticity E ₀ , wherein preferably the ratio of the moduli of elasticity E _H / E _{O is} greater than 1.5, in particular greater than 2, and in particular greater than 3 is. Furthermore, the haptic material has a first refractive index B _H and the optical material has a second refractive index B ₀ , wherein the difference of the refractive indices B _H - B _{0 is} at least 0.03, in particular 0.06 and in particular 0.09 ,

The intraocular lens 1 is implanted in the anterior chamber of an eye. It either serves as a replacement for the natural lens that has been removed due to cataract, for example, or as an adjunct to the natural lens to correct ametropia. The intraocular lens 1 is introduced into the anterior chamber of the eye by a cut in the cornea and attached to the iris by means of the haptic arms 12. For this purpose, the iris between the haptic arms 12 is clamped in the pinching gap 11 of the haptics 3. The width of the pinching gap 11 and the mean roughness of the end faces 21 are dimensioned such that the intraocular lens 1 with the haptics 3 is securely fastened to the iris. The haptic arms 12 bear against the iris with their posterior side surfaces facing the iris, so that the optic 2 is lifted off the iris due to the haptic brackets 13 running obliquely to the lens plane 5 and is exposed. Due to the fact that only the haptic arms 12 are in contact with the iris, the intraocular lens 1 has a good compatibility. The sharp-edged design of the optical edges 9, 10 and the parallel to the optical axis 4 extending edge surface 8 and in particular the asphericity of at least one of the optical surfaces 6, 7 lead to an aberration-free, insbesonde- Moreover, the asphericity of at least one of the optic surfaces 6, 7 can also be used to correct aberrations of the cornea and / or the lens and / or the vitreous body of the eye due to the asphericity of at least one aberration-free intraocular lens.

The geometry of the haptics 3 and their attachment to the optics 2 allow a uniform force in the optic 2 in acting on the haptics 3 forces, whereby aberrations due to deformation of the optic 2 are reduced. In addition, the coating 20 between the haptic material and the optical material reduces aberrations due to disturbing light effects due to the haptic strap 13 extending in the optical material.

Hereinafter, a second embodiment of the intraocular lens Ia will be described with reference to FIG. Identical parts are given the same reference numerals as in the first embodiment, to the description of which reference is hereby made. Structurally different but functionally similar parts receive the same reference numerals with a following a. The main difference with respect to the first exemplary embodiment is that the intraocular lens 1a is designed to be diffractive in a circular central region 24 about the optical axis 4 on at least one of the optical surfaces 6a, 7a. In this case, the central region 24 has a diameter D _d , _ff , which is smaller than the diameter D _{tot of} the entire optical surface 6 a, 7 a. In particular: 0.3 * D _tot <D _dlfT <0.8 * D, _o "in particular 0.4 * D _tot <D _dlff <0.6 * D _tot . In the central region 24, at least one of the optical surfaces 6a, 7a has a plurality of concentric diffraction rings 25 with diameter D ₁ . The diameter D _{1 of} the i-th ring 25, counted from the optical axis 4, is to a good approximation proportional to the root of i. The number of diffracti- ons-rings 25 is at least 5, in particular at least 9. The diffraction rings 25 are each formed as a discontinuity in the surface of the respective optical surface 6a, 7a. The discontinuity is designed in particular as a sharp-edged step with a step height of at least 1.5 μm, in particular at least 3 μm. In this case, each stage is designed such that the thickness of the optics 2a increases in the direction of the optical axis 4 in the radial direction from inside to outside in the region of a step in each case by the step height. In the region of a step, the optics 2a thus has a cylinder jacket-shaped surface parallel to the optical axis 4. As an alternative to a geometric step, the discontinuity may also be given by a change in the refractive power or transparency of the optics 2a.

The optics 2a thus has in the central region 24 at least partially the structure of a Fresnel zone plate and thus forms a diffraction lens in this area. The central region 24 of the optic 2a is bifocal, i. it has a near focus and a far focal point. In this case, the position of the near focal point with respect to the position of the remote focal point corresponds to an increase in the refractive power of the optics 2a of less than 5 diopters, in particular less than 3 diopters, in particular less than 2 diopters.

An edge region 27 connects in the radial direction to the central region 24. The edge region 27 of the optics 2a is monofocal. Its focal point coincides with the remote focal point of the central region 24.

In the following, the function of the intraocular lens Ia will be described. With little open iris, such as in daylight, incident on the optics 2a light in the lens plane 5 has a diameter d, for which d <D _d i _ff . , The edge region 27 of the optics 2a in this case no longer contributes to the optical imaging. In the central region 24 incident on the optics 2a light is focused by the optics 2a on the two focal points. The intensity distribution between the near focal point and the far focal point is independent of the free opening of the iris under these circumstances and is completely given by the properties of the central region 24 of the optics 2a. The intensity in each focal point is at least 20%, in particular at least 30%, in particular at least 40% of the total intensity. About 18% of the incident light is distributed to higher order foci. The optics 2a thus leads to two optical images with different focal lengths. In this case, the image with the shorter focal length of the near vision, that is, the accommodated vision, while the image with the longer focal length of the far vision, ie the unaccommodated sight is used. Central cortical mechanisms lead to the selective dominance of one of the two images in conscious perception.

In weaker light, such as at dusk, the iris continues to open, with the result that the diameter d of the light incident on the optics 2a increases in the area of the lens plane 5. If d> D _diff , the edge region 27 of the optics 2a contributes to the optical imaging. Light impinging on the edge region 27 of the optics 2a is focused into the remote focal point. This results in a relative shift of the intensity distribution in favor of the remote focal point. This is advantageous since in weaker light, such as when driving at night, the near vision loses in importance compared to the distance vision. Hereinafter, a third embodiment will be described with reference to FIG. Identical parts are given the same reference numerals as in the second embodiment, the description of which is hereby incorporated by reference. with referenced. Structurally different but functionally similar parts receive the same reference numerals with a trailing b. The main difference with respect to the second embodiment is that the central region 24b extends substantially over the entire surface of the optic 2b, ie D _d j _ff ~ D _tot - The entire intraocular lens Ib thus acts as a diffractive lens. The intensity distribution between the two focal points is thus independent of the free opening of the iris.

In the following, another embodiment of the intraocular lens Ic will be described with reference to FIGS. 8 and 9. Identical parts are given the same reference numerals as in the first embodiment, to the description of which reference is hereby made. Structurally different but functionally similar parts are given the same reference numerals followed by a c. The main difference with respect to the first embodiment is that the haptic edges 17c, 18c each lie on a circle segment whose radius R _{K is} greater than the radius R _{1 of} the circle through the inner vertices of the connecting portions 16c about the optical axis 4. Furthermore, the fastening portion 15 c is formed in a straight line. The optic 2 is designed according to one of the preceding embodiments.

Due to the course of the haptic edges 17c, 18c, the haptic arms 12c, which are opposite to the pinching gap 11, bend with their roughened end faces 21 during spreading in the posterior direction, that is to say in the direction of the iris. As a result they capture iris tissue during the return movement to their original position and automatically form an iris fold. The attachment of the intraocular lens Ic to the iris by Enclavation of an iris fold and the implantation of the intraocular lens 1 c is thereby further simplified.

Claims

claims

1. Intraocular lens for implantation in an eye, with a. an optic (2; 2a; 2b; 2c) which i. an optical axis (4), ii. a transverse to the optical axis (4) anterior optic surface (6;

6a) and iii. a posterior optic surface (7; 7a) opposite the anterior optic surface (6; 6a), and b. at least two haptics attached to the optic (2; 2a; 2b; 2c)

(3) i. have at least two haptic arms (12, 12c) for fastening the intraocular lens (1, 1a, 1b, 1c) to the iris, c. wherein at least one of the optical surfaces (6, 7; 6a, 7a) is formed aspherical.

2. An intraocular lens according to claim 1, characterized in that at least one of the optical surfaces (6, 7; 6a, 7a) is formed aspherical such that the asphericity by a non-zero Konic factor Q in the range of -10 to + 10, in particular -5 to +5, in particular -1 to +1 is writable.

3. Intraocular lens according to one of claims 1 or 2, characterized in that the optics (2a, 2b) has a circular central region (24, 24b) in which at least one of the optical surfaces (6a,

7a) has a plurality of concentric diffraction rings (25).

4. intraocular lens according to claim 3, characterized in that the diffraction rings (25) are each formed as a discontinuity in the surface of the respective optical surface (6a, 7a).

5. intraocular lens according to claim 4, characterized in that the discontinuity is formed as a sharp-edged step with a step height of at least l, 5μm, in particular at least 3μm.

6. An intraocular lens according to any one of claims 3 to 5, characterized in that the diffractive central region (24; 24b) is bifocal with a near focal point and a far focal point.

7. Intraocular lens according to one of claims 3 to 6, characterized in that the optics (2a) has an edge region 27 which has a focal point which coincides with the remote focal point of the diffractive central region (24).

8. Intraocular lens according to one of claims 1 to 7, characterized in that for attachment of the at least two haptic arms (12; 12c) to the optics (2; 2a; 2b; 2c) in each case at least partially enclosed by the optical material Haptic strap (13) is provided.

9. intraocular lens according to claim 8, characterized in that the haptic strap (13) along at least one haptic edge (17c, 18c) with the haptic arms (12c) are connected, wherein the haptic

Edge (17c, 18c) each lie on a circle segment whose radius (R _κ ) is greater than the radius (Rj) of the circle through the inner vertices of the haptic strap (13) about the optical axis (4).

10. Arrangement of the intraocular lens according to one of the preceding claims in a front chamber of an eye, wherein an iris is clamped in a pinching gap between the haptic arms.