Multifocal intraocular lens

Abstract

To provide a multifocal intraocular lens (IOL).SOLUTION: A multifocal intraocular lens (IOL) 100 includes at least one diffractive surface including a plurality of discrete, adjacent, diffractive, concentric rings 102. The rings are distributed along Fresnel zones (102-1 / 102-2). The at least one diffractive surface includes at least one diffractive surface having a radial phase profile cross-section with a near-symmetrical diffractive surface topography, and an odd number, greater than three, of diffractive orders, and an asymmetrical distribution of energy flux over the diffractive orders.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 730,769, entitled "MULTIFOCAL INTRAOCULAR LENS," filed September 13, 2018, the contents of which are incorporated by reference in their entirety herein.

[0002] The present invention, in some embodiments thereof, relates generally to multifocal intraocular lenses, and more specifically, but not exclusively, to multifocal, diffractive, intraocular ophthalmic lenses. [Background technology]

[0003] An intraocular lens (IOL) is a lens that is implanted in the eye as part of the treatment of cataracts or myopia. Available multifocal IOLs can often restore visual function, making it possible to eliminate the need for glasses after implantation and increasing patient satisfaction.

[0004] Multifocal IOLs correct distance vision, near vision, and all intermediate distances. By dividing light into different foci, multifocal IOLs improve near vision by altering the physiology of vision due to the dispersion of light that occurs as it enters the eye. Modern multifocal IOLs provide a more physiological division of light, thus optimizing spectacle independence and improving the quality of vision and reducing visual symptoms for patients.

[0005] The foregoing examples of the related art and limitations associated therewith are intended to be illustrative and not exhaustive. Other limitations of the related art will become apparent to those of ordinary skill in the art upon reading this specification and studying the drawings. Summary of the Invention

[0006] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools, and methods that are meant to be exemplary and illustrative, not limiting in scope.

[0007] According to some embodiments of the present invention, there is provided a multifocal IOL comprising at least one diffractive surface having a radial phase profile cross-section including a plurality of discrete adjacent diffractive concentric rings, the radial phase profile cross-section having a substantially symmetric diffractive surface topography and an odd number of diffraction orders greater than three. In some embodiments, the IOL comprises an asymmetric distribution of energy flux across the diffractive orders.

[0008] In some embodiments, the IOL comprises five diffractive orders. The diffractive surface includes diffractive steps designed to maintain a constant diffractive profile between steps, the diffractive steps being partially inside and partially outside the base curvature of the IOL. In some embodiments, the diffractive concentric rings comprise a repeating pattern of a diffractive profile, hi some embodiments, the profile is asymmetric.

[0009] In some embodiments, the diffractive ring comprises a repeating pattern of a single diffractive profile, hi some embodiments, the diffractive ring comprises a repeating pattern of two different diffractive profiles, where the diffractive ring comprises a single transition from a first zone having a repeating pattern of one diffractive profile to a second peripheral zone having a repeating pattern of a second diffractive profile.

[0010] In some embodiments, the height of the diffractive surface topography of the second peripheral zone remains constant as it advances radially outward relative to the central height of the IOL. In some embodiments, the radial phase profile cross-section has an asymmetric double peak shape.

[0011] In some embodiments, the thickness of the IOL is variable and the curvature is maintained, In some embodiments, the thickness of the IOL is variable and the curvature is variable.

[0012] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed description. [Brief description of the drawings]

[0013] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0014] Exemplary embodiments are illustrated in the reference figures. Dimensions of components and features shown in the figures have generally been chosen for convenience and clarity of presentation and have not necessarily been shown to scale. The figures are as follows:

[0015] [Figure 1A] FIG. 1 is a simplified diagram of a plan view of a multifocal IOL. [Figure 1B] 1 is a simplified diagram of a cross-sectional view of a diffractive surface of a multifocal IOL, according to some embodiments of the present invention. [Figure 2A] 1 is a simplified diagram of a radial cross section of the diffractive surface topography of a portion of an IOL. [Figure 2B] 2B is a graph of the distribution of energy flux (power) levels across particular diffraction orders associated with the diffractive surface topography shown in FIG. 2A. [Figure 3A] 1 is a simplified diagram of a radial cross section of the diffractive surface topography of a portion of an IOL. [Figure 3B] 3B is a graph of the distribution of energy flux (power) levels across particular diffraction orders associated with the diffractive surface topography shown in FIG. 3A. [Figure 4] 1 is a graph showing two superimposed radial phase profiles according to some examples of the present invention. [Figure 5A] 1 is a simplified diagram of a radial cross section of the diffractive surface topography of a portion of an IOL. [Figure 5B]5B is a graph of the distribution of energy flux (power) levels across particular diffraction orders associated with the diffractive surface topography shown in FIG. 5A. [Figure 6] 1 is a graph of a simulation of the through-focus modulation transfer function (MTF) of an IOL in accordance with some embodiments of the present invention. [Figure 7] 1 is a simplified graphical diagram illustrating a profile of a diffractive portion of an exemplary lens, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] To better understand certain embodiments of the present invention, reference will first be made to the construction and operation of a multifocal intraocular lens (IOL), as illustrated in FIGS. 1A-6 of the drawings.

[0017] Multifocal intraocular lenses (IOLs) are designed to generate one, two, three or more diffraction orders or foci on the optical axis, so that each image focus is formed on the retina when the object related to the image is located at a corresponding distance from the eye. Most intraocular lenses are designed to have a refractive (lens) focus and an energy flux (power) corresponding to distance vision, i.e. the spherical / aspheric surface of the lens is designed to focus the image of an object on the retina when the object is located at a hyperopic distance (>5-6 meters) from the eye. The diffractive surface of most bifocal and trifocal lenses creates additional foci at near (30-40 cm) and intermediate (60-80 cm) distances.

[0018] Most refractive diffractive IOLs have the same general structure: a lens containing multiple rings, each with a diffractive profile scaled to the ring width. The diffractive profile is repeated along the radius of each Fresnel zone. In some cases, the rings are also scaled vertically (apodization).

[0019] According to one aspect of the invention, an IOL is provided that includes diffractive steps that are partially inside and partially outside the base curvature of the IOL. In some embodiments, the thickness of the IOL is variable and the curvature is constant. In some embodiments, the change in curvature occurs by optimizing the sphericity between the steps.

[0020] According to an aspect of some embodiments of the present invention, an IOL having a spherical surface and an aspheric surface is provided. In some embodiments, the IOL includes an asymmetric number of active diffractive orders along the optical axis of the eye. In some embodiments, the IOL includes more than three diffractive orders on the optical axis of the eye. In some embodiments, the IOL includes five diffractive orders on the optical axis.

[0021] In some embodiments, the IOL comprises a diffractive pattern on one or more surfaces of the lens. In some embodiments, the diffractive pattern comprises a repeating pattern of a diffractive profile. In some embodiments, the profile is asymmetric.

[0022] Reference is now made to Figures 1A and 1B (not drawn to scale), where Figure 1A is a simplified diagram of a plan view of a multifocal IOL and Figure 1B is a simplified diagram of a cross-sectional view of a diffractive surface of the multifocal IOL, in accordance with some embodiments of the present invention.

[0023] As shown in the exemplary embodiment depicted in FIG. 1A, the IOL 100 includes a diffractive surface having a plurality of discrete, adjacent diffractive concentric sections or rings 102 .

[0024] In some embodiments, the IOL diffractive surface includes a diffractive step that is partially inside and partially outside the base curvature of the IOL. This results in a change in diffractive state between the two steps. In some embodiments, the thickness of the IOL is variable, but the curvature is maintained. In some embodiments, the change in curvature occurs by optimization of sphericity between the steps.

[0025] Potential advantages of the described design include: 1. The diffractive step design does not change the diffractive profile between steps, which makes it possible to have a more efficient multifocal IOL with any power added at the near focal distance without losing distance contrast. 2. The design of the diffractive steps allows the light beam to be parallel to the step, an ideal condition for diffraction.

[0026] In some embodiments, the rings are distributed along the Fresnel zones (102-1 / 102-2). In some embodiments, as shown in FIG. 1B, the IOL surface 150 topography is characterized by a repetitive triangular, square, or parabolic morphology, depending on the type of lens.

[0027] Reference is now made to FIG. 2A, which is a simplified diagram of a radial cross-section of the diffractive surface topography of a portion of an IOL, and reference is made to FIG. 2B, which is a graph of the distribution of energy flux (power) levels over particular diffraction orders associated with the diffractive surface topography shown in FIG. 2A.

[0028] FIG. 2A shows a radial cross section or radial phase profile 200 of the diffractive surface topography through the concentric rings. A particular cross section of the radial phase profile is generated using a Gerchberg-Saxton (GS) iterative algorithm. FIG. 2A shows an exemplary embodiment of a radial phase profile cross section showing an asymmetric double peak cross section with a nearly symmetric local diffractive surface topography. The radial phase profile 200 is converted to a height profile that is radially and parabolically integrated into each of the Fresnel zones (rings) of a diffractive lens with a particular focal length.

[0029] The authors of the present disclosure have come to know that a symmetric local diffractive surface topography function, when combined with an odd number of diffraction orders, e.g., 1, 3, 5, 7, or 9 diffraction orders, particularly greater than three diffraction orders, can improve the overall light transmission efficiency of the IOL to greater than 90%, and in some cases, to at least 93%.

[0030] In some embodiments, the IOL 100 includes five diffraction orders on the optical axis. In some embodiments, one of the diffraction orders, e.g., the far vision focal length, has a high energy flux level. In some embodiments, one of the diffraction orders is completely suppressed. In some embodiments, the five diffraction orders or focal points correspond to the following five diffraction orders: -2, -1, +1, and +2, which are the diffraction orders of the diffraction caused by the diffraction pattern, and a single order 0, which is the refractive power caused by the spherical / aspheric surface of the IOL. In some embodiments, the spherical / aspheric surface of the lens is designed to focus the image on the retina when the object to be imaged is located at an intermediate distance between near vision (approximately 30-40 cm) and far vision (several meters) from the eye.

[0031] In some embodiments, as shown in FIG. 2B, among the five diffraction orders, the diffraction order −2 corresponds to the far vision and has the highest energy flux level. In some embodiments, among the remaining diffraction orders, the diffraction order +2 corresponds to the near vision and has the highest energy flux level. In this embodiment, the diffraction order −1 is suppressed.

[0032] Reference is now made to FIG. 3A, which is a simplified illustration of a radial cross-section of the diffractive surface topography of a portion of an IOL, and to FIG. 3B, which is a graph of the distribution of energy flux levels over particular diffraction orders associated with the diffractive surface topography shown in FIG. 3A.

[0033] 3A and 3B show different designs than those shown in FIGS. 2A and 2B, but both are designed using the same method of profile generation using the Gerchberg-Saxton (GS) iterative algorithm and conversion of the phase profile to a height profile that is radially and parabolically integrated into each of the Fresnel zones (rings) of a diffractive lens with a specific focal length.

[0034] 3A shows an additional example of a radial cross section or radial phase profile 300 of the diffractive surface topography through concentric rings. FIG. 3A shows an exemplary embodiment of a radial phase profile exhibiting an asymmetric double peak cross section with a nearly symmetric local diffractive surface topography. The radial phase profile 300 is transformed into a height profile that is radially and parabolically integrated into each of the Fresnel zones (rings) of a diffractive lens having a particular focal length.

[0035] In some embodiments, as shown in FIG. 3B, among the five diffraction orders, diffraction order −2 corresponds to far vision and has the highest energy flux level. In some embodiments, among the remaining diffraction orders, diffraction order +2 corresponds to near vision and has the highest energy flux level, and the energy flux level at order 0 is higher than the energy flux level at diffraction order +1. In this embodiment, diffraction order −1 is suppressed.

[0036] As shown in FIG. 4, which is a graph of radial phase profile 300 superimposed on radial phase profile 200, demonstrates the phase difference between designs according to some examples of the present invention. When using this approach with five or more foci (e.g., seven), the diffractive focal length determines the location of the far focus (diffractive order -3) and the near focus (diffractive order +3), and the refractive focal length (spherical) determines the location of one of the intermediate foci (order 0). In the exemplary embodiment shown in FIG. 4, the radial phase profile 200 includes phases of 1, 0, 0.333, 0.38, and 0.637, and the radial phase profile 300 includes phases of 1, 0, 0.6, 0.45, and 0.65. In some embodiments, the IOL includes two zones: a central zone 102-1 (FIGS. 1A and 1B) and a peripheral zone 102-2. In some embodiments, the diffractive pattern of the central zone 102-1 is not apodized. In some circumstances, the diffractive pattern of the peripheral zone 102-2 is not apodized. The height of the diffractive surface topography of the zone 102-2 remains constant and does not have a gradual step height decrease as one progresses radially outward relative to the central height of the IOL. This arrangement and design is planned with the diffractive orders such that increasing the aperture changes the intensity distribution and can increase the luminous flux even with a dilated pupil (low intensity environment) light that is not optimally focused.

[0037] A potential advantage of this design is that the apodized design allows for diffraction efficiency close to 100%, thus minimizing light loss.

[0038] When modifying the intensity distribution as a function of aperture size, the approach used here is to change the diffraction pattern at (or near) any radius or one of the Fresnel zones of the intraocular lens to improve performance. In the present invention, the design transition occurred at a radius of approximately 1.228 mm.

[0039] As shown in Figures 5A and 5B, Figure 5A illustrates an example radial cross-section or radial phase profile 500 of a diffractive surface topography through concentric rings in a peripheral zone of an IOL, according to some embodiments of the present invention. Figure 5A illustrates an exemplary embodiment of a radial phase profile cross-section at an IOL peripheral zone 102-2, showing an asymmetric single peak cross-section with a nearly symmetric local diffractive surface topography.

[0040] In some embodiments, the radial phase profile cross-section at the IOL peripheral zone 102-2 comprises an asymmetric double peak cross-section with a nearly symmetric local diffractive surface topography. The radial phase profile 500 is transformed into a height profile that is radially and parabolically integrated into each of the Fresnel zones (rings) of a diffractive lens having a particular focal length.

[0041] In some embodiments, as shown in FIG. 5B, the flux energy level decreases from the far diffraction order to the near diffraction order with two suppressed orders, −1 and +1.

[0042] The phases acquired at the source plane shown in Figures 5A and 5B and used in the design (radius > 1.228 mm) are obtained using the normalized target intensity [1, 0, 0.5, 0, 0.34] with the Gerchberg-Saxton (GS) algorithm.

[0043] However, in some embodiments, the other diffractive profile (after transition) can be a different diffractive design based on three or more foci, and can also be a monofocal design with full energy at distance vision, or a bifocal design with energy at distance vision and other foci at intermediate or near vision.

[0044] Also, the entire diffractive height profile (before and after the transition from IOL zone 102-1 to IOL zone 102-2) can be adjusted to fine-tune the intraocular lens. In the exemplary embodiment shown in Figures 5A and 5B, the first diffractive profile before the transition increased by 5% and the second diffractive profile after the transition increased by 12%. Our multifocal IOL is based on the zeroth order for intermediate vision and has a high efficiency of over 90% for the diffractive orders used (-2, -1, 0, 1, 2).

[0045] Reference is now made to Figure 6, which is a graph of a simulation of the through-focus modulation transfer function (MTF) of an IOL, according to some embodiments of the present invention. As shown in the exemplary embodiment shown in Figure 5, three graphs are plotted for three levels of eye pupil diameter: graph 602 for a 2 mm pupil diameter (i.e., strong light conditions), graph 604 for a 4.5 mm pupil diameter (i.e., low light conditions), and graph 606 for a 3 mm pupil diameter (i.e., normal light conditions).

[0046] The graph shown in Figure 6 presents the biphasic nature of the IOL at all three levels of ambient light shown, however, as the ambient light level is reduced and the pupil diameter changes from 2 mm to 4.5 mm, the MTF values ​​increase in the far vision range of the IOL, even though the MTF values ​​are accordingly restricted from a diopter range of approximately 22-24.5 to a narrower diopter range of approximately 23-23.75, allowing for improved visual acuity at low light intensities.

[0047] 7 is a simplified graphical diagram illustrating a profile of a diffractive portion of an exemplary lens, according to some embodiments of the present invention. As shown in FIG. 7, the depicted cross-sectional profile includes an asymmetric single-peak topography that includes multiple peaks having heights of 1.5-2.5 μM distributed along a portion of the lens radius from 0-3000 μM.

[0048] Throughout this application, various embodiments of the present invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the present invention. Thus, the description of a range should be considered to specifically disclose all possible subranges as well as individual numerical values ​​within that range. For example, the description of a range such as 1-6 should be considered to specifically disclose subranges such as 1-3, 1-4, 1-5, 2-4, 2-6, 3-6, etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0049] Whenever a numerical range is given herein, it is meant to include any cited numbers (fractional or integer) within the indicated range. The phrases "ranging between" a first indicated number and a second indicated number and "ranging between" a first indicated number and a second indicated number are used interchangeably herein and are meant to include the first and second indicated numbers and all fractional and integer numbers therebetween.

[0050] In the description and claims of this application, the words "comprise," "include," and "have," and each of their forms, do not necessarily limit the members in a list with which the word may be associated. Furthermore, in the event of a conflict between this application and any document incorporated by reference, it is hereby intended that the present application shall control.

[0051] The description of various embodiments of the present invention has been presented for illustrative purposes, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used in this specification are selected to best explain the principles of the embodiments, practical applications, or technical improvements to the technology found in the market, or to allow persons other than those skilled in the art to understand the embodiments disclosed herein.

Claims

1. 1. A multifocal intraocular lens (IOL) comprising at least one diffractive surface including a plurality of discrete adjacent diffractive concentric Fresnel zones, the Fresnel zone comprises a first zone having a repeating pattern of a first diffractive profile and a second zone having a repeating pattern of a second diffractive profile, the first zone being centrally disposed with respect to the IOL and the second zone being peripherally disposed about the first zone; the first diffractive profile and the second diffractive profile each generate an energy flux distribution over five diffractive orders, −2, −1, 0, +1, and +2, the five diffractive orders including at least a vision-providing order comprising a diffractive order −2 providing distance vision, a diffractive order +2 providing near vision, and a diffractive order 0 providing a first intermediate vision; from the first zone, the −2 diffraction order and the +2 diffraction order have the two highest energy fluxes of the five diffraction orders; From the second zone, the energy flux decreases as the visual acuity providing order increases. Multifocal IOL.

2. The multifocal IOL of claim 1 , wherein from the first zone, the diffraction order −2 has the highest energy flux of the five diffraction orders and the diffraction order +2 has the second highest energy flux of the five diffraction orders.

3. The multifocal IOL of claim 1 , wherein from the first zone, a diffraction order of +1 provides a second intermediate visual acuity.

4. The multifocal IOL of claim 3 , wherein from said first zone, the −1 diffraction order is suppressed.

5. The multifocal IOL of claim 4 , wherein from the second zone, the −1 and +1 diffraction orders are suppressed.

6. The multifocal IOL of claim 1 with an efficiency of greater than 90% in the five diffraction orders.

7. The multifocal IOL of claim 6 , wherein the efficiency is at least 93%.

8. 1. A multifocal intraocular lens (IOL) comprising at least one diffractive surface including a plurality of discrete adjacent diffractive concentric Fresnel zones, the at least one diffractive surface produces an asymmetric distribution of energy flux over more than three successive diffraction orders; the Fresnel zone comprises a first zone having a repeating pattern of a first diffractive profile and a second zone having a repeating pattern of a second diffractive profile, the first zone being centrally disposed with respect to the IOL and the second zone being peripherally disposed about the first zone; the first diffractive profile and the second diffractive profile each generate an energy flux distribution over the more than three consecutive diffractive orders, the more than three consecutive diffractive orders including at least a lowest diffractive order of the more than three consecutive diffractive orders that provides a far focus of the multifocal IOL, a highest diffractive order of the more than three consecutive diffractive orders that provides a near focus of the multifocal IOL, and a vision-providing order comprising a refractive order 0 that provides a first intermediate focus of the multifocal IOL; from the first zone, the lowest diffraction order of the more than three consecutive diffraction orders and the highest diffraction order of the more than three consecutive diffraction orders have the two highest energy fluxes of the more than three consecutive diffraction orders; From the second zone, the energy flux decreases as the visual acuity providing order increases. Multifocal IOL.

9. The multifocal IOL of claim 8 , wherein the more than three consecutive diffraction orders consist of an odd number of diffraction orders.

10. 9. The multifocal IOL of claim 8, wherein from the first zone, the lowest diffraction order has the highest energy flux of the more than three consecutive diffraction orders, and the highest diffraction order has the second highest energy flux of the more than three consecutive diffraction orders from the first zone.

11. The multifocal IOL of claim 8 , wherein from the first zone, vision-providing orders included among the more than three consecutive diffraction orders further comprise at least one additional intermediate focus.

12. The multifocal IOL of claim 11 , wherein the more than three consecutive orders produced by the first zone comprise suppressed orders consisting of a first suppressed order.

13. The multifocal IOL of claim 12 , wherein the more than three orders produced by the second zone further comprise the first suppressed order and at least one second suppressed order.

14. The multifocal IOL of claim 8 , wherein the first diffractive profile is asymmetric.

15. The multifocal IOL of claim 8 , wherein the first diffractive profile has an asymmetric double peak shape.

16. The multifocal IOL of claim 8 , wherein the at least one diffractive surface comprises a diffractive step.

17. The multifocal IOL of claim 16 , wherein the diffractive steps are partially inside and partially outside the base curvature of the multifocal IOL.

18. The multifocal IOL of claim 16, wherein the thickness of the multifocal IOL is variable and the curvature of the multifocal IOL is maintained during the diffractive step.

19. The multifocal IOL of claim 16, wherein the thickness of the multifocal IOL is variable and the curvature of the multifocal IOL is variable during the diffractive step.

20. The multifocal IOL of claim 8 with greater than 90% efficiency in the more than three consecutive diffraction orders.

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