Intraocular lens with predetermined bending point on the haptic surface

Description

[0001] The invention relates to an intraocular lens as an implant for replacing a natural lens in the capsular bag of an eye according to the preamble of claim 1.

[0002] Various designs of intraocular lenses are known from the prior art, for example from CN 207136934 U or US 2019 / 183632 A1.

[0003] The object of the invention is to provide an intraocular lens that enables better and safer positioning of the optical lens during insertion.

[0004] Starting from an intraocular lens of the type mentioned above, the problem is solved by the characterizing features of claim 1.

[0005] The measures mentioned in the dependent claims make advantageous embodiments and further developments of the invention possible.

[0006] Typically, the intraocular lens according to the invention can be used in cases of diseases, age-related conditions, or similar situations where the natural lens in the eye, more precisely, within the capsular bag, needs to be replaced because it has become clouded, for example, due to cataracts. The clouded lens can be removed from the capsular bag through an access point via the cornea or sclera. The capsular bag itself is attached to the zonular fibers, which in turn are attached to the ciliary muscle. The intraocular lens is inserted into the capsular bag whenever possible. The intraocular lens according to the invention is held and centered within the capsular bag. It initially comprises, as its optical component, a lens body to form the central optical lens.Accordingly, the optical lens has an optical axis, i.e., an axis of symmetry of the lens, which itself represents an essentially rotationally symmetric, toric or multifocal optical system.

[0007] At the edge of the lens body of the intraocular lens according to the invention, a so-called haptic or haptic device is attached, which fixes the lens in the capsular bag. It is designed in such a way that it slightly stretches the capsular bag and centers the lens within it, thus making subsequent slippage of the lens more difficult and enabling the desired optical image. The haptic device lies in a mounting plane perpendicular to the optical axis of the lens body.

[0008] In this case, the device has at least one retaining element that is at least partially arcuate. This can be an arm projecting radially from the lens, or one that curves slightly outwards. It is also conceivable that closed geometric shapes such as rings or the like could be used as retaining elements. This arm or retaining element is inherently flexible and also possesses a certain degree of elasticity, meaning that the entire intraocular lens (haptic with lens body) can be easily inserted into the eye through narrow openings due to its flexibility, for example, by rolling the lens up. The lens can also adapt well to the geometric conditions within the capsular bag.Due to a certain degree of elasticity, the haptic device presses against the lens capsule, tensioning it laterally in the plane of support and slightly stretching it. This force between the edge of the lens capsule and the haptic device simultaneously stretches the lens body, holding it firmly in place within the capsule and preventing any slippage. This ensures optimal optical centering.

[0009] The intraocular lens according to the invention is characterized in that the mounting element has at least one predetermined bending point, the width of which in the bearing plane is less than the thickness in the direction of the optical axis. In order for a force to be exerted on the lens body via the mounting element, thus fixing and centering it, it is advantageous that the total diameter of the intraocular lens, including the haptic device, is slightly larger in the non-implanted case than the diameter of the capsular bag after removal of the natural lens. This allows the haptic device or the mounting elements to be easily compressed radially or towards the optical axis, and their elasticity to exert a force on the capsular bag or on the lens body, thus holding it in its position.

[0010] When the retaining elements are pressed radially inwards towards the optical axis during insertion into the lens capsule, they will inevitably bend at the point of least mechanical resistance. With conventional intraocular lenses of the prior art, the force acting radially to the lens body during insertion into the capsule can overstress the elasticity of the retaining elements, causing them to buckle. This results in one or both retaining elements yielding, for example, in the direction of the optical axis / perpendicular to the mounting plane, and tilting out of this plane. As a direct consequence, the lens body, or rather its optical axis, is then also tilted relative to the optical axis of the eye.This results in the conventional lens implanted thus not providing the desired optical image, which worsens the visual quality without additional optical correction (glasses or contact lens).

[0011] In practice, it is observed that the lens size varies for different patients depending on the individual case. Nearsighted patients generally have larger lenses than farsighted patients. Nevertheless, intraocular lenses are usually not custom-made for each patient or manufactured in graduated sizes for different eye sizes.

[0012] However, due to the predetermined bending points according to the invention, the point at which the mounting elements yield due to their flexibility is mechanically predetermined, and this occurs within the bearing plane, thus preventing the lens body from tilting. This allows for positioning with significantly increased precision.

[0013] Within the mounting element, the intended bending point can be formed as a singularity in the geometric shape of the mounting elements. On at least one, and in particular both, sides of the intended bending point, a region can be added whose width, measured in the bearing plane, is at least as large as the thickness of the corresponding mounting element in the direction of the optical axis. In principle, it is conceivable that this intended bending point is located directly where the mounting element attaches to the lens body. However, for reasons of stability and additionally to better and more uniformly adapt the curvature of the mounting element to the edge of the lens capsule, the intended bending point can also be positioned further radially outwards on the mounting element, i.e., further away from the lens body, in one embodiment of the invention.To achieve an even better adaptation of the mounting element to the curvature of the edge of the capsule bag, two or more predetermined bending points can be provided on a mounting element.

[0014] Firstly, the predetermined bending point can allow for a more flexible adaptation to the capsular bag; secondly, the retaining element can be designed with a certain degree of elasticity, so that the intraocular lens exerts a force on the capsular bag via the retaining element, causing it to stretch slightly while still allowing it to adapt to any potential shrinkage of the capsular bag. Furthermore, the lens body itself is then fixed and centered.

[0015] In an advantageous embodiment of the invention, the haptic device is designed such that the retaining elements are arranged around the lens body in a mirror-symmetrical manner with respect to a line in the support plane that runs perpendicularly through the optical axis and / or at equal angular intervals with respect to the center of the lens body in the support plane. Both arrangements fundamentally enable a stable and, above all, well-centered positioning of the lens body in the eye.

[0016] To manufacture the intraocular lens as cost-effectively as possible, at least one of the intended bending points is designed as a recess, particularly with a smooth edge. This weakening in the area of ​​the retention element's width at one point allows it to yield more easily when inserted into the capsular bag and bend in the plane of support. No hinge or similar mechanism is necessary; material is simply removed. The smooth edge allows for a certain degree of elasticity even at the intended bending point, whereas with a notch featuring edges, the material is more likely to lose its elasticity and buckle. The intended bending point can, in principle, be surrounded by material from the retention element. dhIt represents a hole within the material. Advantageously, the intended bending point can be open on one side, so that the direction in which the material bends is more clearly defined, i.e., towards the opening. This measure offers a comparatively simple and cost-effective manufacturing process.

[0017] In one embodiment of the invention, the intended bending point can be located, in particular, on the inside of the respective arc-shaped mounting element. Due to the bending, the mounting element will primarily continue to curve in the direction of this bend. When the intraocular lens is inserted into the lens capsule, with such a C-shaped haptic, the lens is rotated so that it faces the opposite direction to the curvature of the mounting elements, preventing the mounting elements from folding over against their curvature. Thus, if the curvature is, for example, left-handed and the mounting elements point, for example, counterclockwise from the observer's perspective, the lens is rotated clockwise when inserted into the lens capsule and subsequently positioned, allowing the mounting elements to fit snugly against the edge of the lens capsule.

[0018] Regarding manufacturing, it is particularly advantageous if the lens body or the lens body shell and the haptic element itself are manufactured as a single piece or from the same material. With conventional intraocular lenses from the prior art, where the haptic element and lens body are made of different materials, the haptic element and optics must first be joined together, for example, by drilling very small holes into the lens body and then attaching and bonding the haptic element into these holes. While this has the advantage that comparatively thin haptic elements with advantageous properties specifically dictated by the material selection can be chosen, it also presents the problem that not only is the manufacturing process very complex, but errors are also more likely to occur when attaching the haptic element to the lens body, and it may detach over time.Furthermore, such lenses are usually very expensive.

[0019] According to the invention, so-called C-haptics are suitable, which have curved retaining elements shaped like an arm, i.e., one end of the retaining element is connected to the lens body, while the other is free. The haptic device can generally comprise at least two, and in particular three or four, retaining elements. It is also conceivable that the retaining elements have a closed arc that encloses a recess. Thus, the recess is deformed when inserted into the capsular bag. Especially with C-haptics, the retaining elements can generally be arranged curved in the same direction, so that the lens can be brought into its final position by rotation during positioning, and the retaining elements, in the form of arms or C-articles, find their correct position according to their curvature without twisting. In this way, stable retaining positioning of the intraocular lens can be achieved.

[0020] When inserting an intraocular lens into the capsular bag of an eye, an intraocular lens according to the invention, or an embodiment thereof, is used. Through a surgical opening in the peripheral cornea or the adjacent sclera, the intraocular lens is moved into the capsular bag using an insertion device similar to a syringe. The intraocular lens is typically forced through a relatively thick cannula. To ensure this occurs in a controlled manner and to prevent damage to the intraocular lens, it is first rolled tightly around the insertion axis so that the opposite ends overlap. Once the intraocular lens enters the capsular bag, it is no longer subject to the mechanical constraints that hold it in its rolled-up form within the cannula and unfolds.The surgeon then usually had to reposition the lens and, for example, rotate it until the retaining elements fit snugly against the edge of the capsular bag, center the lens and at the same time slightly stretch the capsular bag outwards. Examples of implementation

[0021] Exemplary embodiments of the invention are shown in the drawing and are explained in more detail below, including further details and advantages. Specifically, the drawing shows: Figure 1: an intraocular lens according to the invention with a predetermined bending point in the mounting element, and Figure 2: an intraocular lens according to the invention with two predetermined bending points on each mounting element.

[0022] Figure 1Figure 1 shows an intraocular lens 1, viewed along the optical axis OA, according to the invention, with a lens body 2. The haptic device 3 comprises two mounting elements 4, offset by 180° from each other, which are designed as C-haptics. Following one of the mounting elements 4 radially outwards from the lens body 2, i.e., from the point where the respective mounting element 4 attaches to the lens body 2, it can be seen that the respective mounting element 4 constricts at the predetermined bending point 5. This constriction is caused by a recess at the inner edge of the curvature of the mounting element 4.

[0023] Figure 2 Figure 1 again shows a similar intraocular lens 11 with a lens body 12 and a haptic device 13, which is analogous to the embodiment according to Figure 1 has mounting elements 14 offset by 180° from each other. In contrast to the embodiment according to Figure 1However, two predetermined bending points 15, 16 are provided for each support element 14. Since these predetermined bending points 15, 16 are in close proximity to one another, the primary concern here is ensuring sufficient flexibility. The intraocular lenses 1, 11 according to the Figure 1 and 2 are formed in one piece.

[0024] The drawing plane of the Figure 1 and 2 corresponds to storage level E (also in the capsular bag). Reference symbol:

[0025] 1 Intraocular lens (IOL) 2 Lens body 3 Haptic device 4 Retaining elements 5 Target bending point 11 Intraocular lens 12 Lens body 13 Haptic device 14 Retaining elements 15 Target bending point 16 Target bending point E Mounting plane O Optical axis of the IOL

Claims

1. Intraocular lens (1, 11) as an implant for replacing a natural lens in the capsular bag of an eye, comprising: • a lens body (2, 12) for forming the central optical lens, which has an optical axis (OA), • a haptic device (3, 13) attached to the edge of the lens body (2, 12), for fixing the intraocular lens (1, 11) in the capsular bag and / or for stretching the capsular bag and / or for centring the lens body (2, 12) in the capsular bag, • wherein the haptic device (3, 13) lies in a bearing plane (E) which is perpendicular to the optical axis (OA) of the lens body (2, 12), • wherein the haptic device (3, 13) comprises at least one at least partially arcuate holding element (4, 14), • wherein the at least one holding element (4, 14) has at least one predetermined bending point (5, 15, 16), wherein the predetermined bending point or several predetermined bending points (15, 16) on at least one of the holding elements (14) is / are designed as a recess with a smooth edge profile, and wherein the predetermined bending point is designed as a material cutout and as a weakening at one location in the region of the width of the holding element, in order to more easily yield during insertion into the capsular bag and to bend in the bearing plane, characterized in that the width of the predetermined bending point (5, 15, 16) in the bearing plane (E) is less than the thickness in the direction of the optical axis (OA), wherein all of the holding elements (4, 14) are designed as C-haptics and both sides of the predetermined bending point (5, 15, 16) are adjoined by a region whose width in the bearing plane (E) is at least as great as, in particular greater than, the thickness of the corresponding holding element (4, 14) in the direction of the optical axis (OA).

2. Intraocular lens (1, 11) according to Claim 1, characterized in that: • the haptic device (3, 13) comprises two or more holding elements, and / or • the holding elements (4, 14) are arranged curved in the same direction.

3. Intraocular lens (1, 11) according to either of the preceding claims, characterized in that the holding elements (4, 14) around the lens body (2, 12): • are arranged mirror-symmetrically with respect to a line in the bearing plane (E) perpendicular to the optical axis (OA), and / or • are arranged, in the bearing plane (E), at the same angular intervals with respect to the centre of the lens body (2, 12).

4. Intraocular lens (1, 11) according to any one of the preceding claims, characterized in that the recess of the at least one predetermined bending point (5, 15, 16) is designed open.

5. Intraocular lens (1, 11) according to any one of the preceding claims, characterized in that the recess of the at least one predetermined bending point (5, 15, 16) is arranged on the inner side of the respective arcuate holding element (4, 14).

6. Intraocular lens (1, 11) according to any one of the preceding claims, characterized in that • the lens body (2, 12) and / or the envelope of the lens body and also the haptic device (3, 13) are produced in one piece and / or from the same material.