WO2024118991A1

WO2024118991A1 - Augmented ophthalmic lens with odd asphere axicon refractive optics

Info

Publication number: WO2024118991A1
Application number: PCT/US2023/081949
Authority: WO
Inventors: Yueai Liu
Original assignee: Aaren Scientific Inc.
Priority date: 2022-12-02
Filing date: 2023-11-30
Publication date: 2024-06-06
Also published as: WO2024118991A4

Abstract

The invention relates to a novel ophthalmic lens designed to extend the depth of focus for a patient using the lens. The lens comprises an optic having an anterior surface, a posterior surface, and an optical axis. At least one of the anterior surface and the posterior surface includes a first zone extending from the optical axis to a first radial boundary and a second zone extending from the first radial boundary to the edge of the optic. The first zone comprises a surface having the characteristics of an odd asphere axicon, while the second zone comprises a surface having the characteristics of an even asphere. If the ophthalmic lens is intraocular, haptics will be attached to the optic to hold the lens in place after insertion into a human ocular capsular bag.

Description

TITLE Augmented Ophthalmic Lens with Odd Asphere Axicon Refractive Optics CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. Provisional Patent Application No.63/385,797 filed on December 2, 2022. The entire disclosure of the prior application is considered to be part of the disclosure of the accompanying application and is hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention This present disclosure relates generally ophthalmic lenses and, more particularly, to ophthalmic lenses having an optic comprised of two zones configured to extend the depth of focus. 2. Description of the Related Art A common form of eye disease among the senior population is cataracts. A cataract is a cloudy area in the eye's lens that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes and many times lead to difficulties in performing daily tasks such as driving, reading, or recognizing faces. If left untreated, cataracts may lead to blindness. A common form of treatment is to remove the natural lens, called the crystalline lens, and replace it with a prosthetic lens called an intraocular lens (IOL). An IOL can be designed to provide a good visual acuity for a single focal point or for several focal points. The former is referred to as a monofocal IOL and generally uses an aspheric surface. In contrast, the latter is referred to as a multifocal IOL and uses a diffractive surface. A multifocal IOL, having more than one focal point, is often preferred over a monofocal IOL as such lenses generally eliminate the need for glasses. However, multifocal lenses are more expensive than monofocal lenses because of their diffractive design, and patients using multifocal lenses are many times less satisfied with their vision experience than patients using monofocal lenses. As a result, many IOL monofocal designs seek to improve the lens’s single focal point by increasing its depth of focus at its single focal point by modifying its aspherical surface. United States publication 20200121448 to Myoung-Taek Choi et al. titled “Extended depth of focus intraocular lens” discloses an IOL that comprises an optic zone and a modulated surface profile formed in the optic zone and configured to focus incident light at a plurality of focal points, wherein the modulated surface profile is incorporated with a base surface profile of the optic zone. The modulated surface may have a profile that is sinusoidal, triangular, or some form thereof, the purpose of which is to extend the depth of focus. Another example is United States patent 11083566 to Xin Hong et al. titled “Ophthalmic lens having an extended depth of focus.” Here, Hong discloses ophthalmic lens that includes an optic having an anterior surface, a posterior surface, and an optical axis. At least one of the anterior surface and the posterior surface includes a first zone extending from the optical axis to a first radial boundary and a second zone extending from the first radial boundary to the edge of the optic. The first zone includes an inner region and an outer region separated by a phase shift feature, the phase shift comprising a ridge extending outwardly from the inner region and the outer region. The optical combination of the inner region, phase shift feature, and outer region of the first zone and the second zone extends the depth of focus of the lens. BRIEF SUMMARY OF THE INVENTION What is disclosed herein is an ophthalmic lens, generally an IOL, where in certain embodiments, the optic having an anterior surface, a posterior surface, and an optical axis. At least one of the anterior surface and the posterior surface includes a first zone extending from the optical axis to a first radial boundary and a second zone extending from the first radial boundary to the edge of the optic. The first zone having a surface comprised of an even asphere modified with an odd asphere axicon (OAA), while the second zone is a normal conic surface or an even asphere surface. By modifying the parameters of the OAA, an infinite number of embodiments may be created, of which some are disclosed herein. Neither this summary nor the following detailed description defines or limits the invention. The claims define the invention. BRIEF DESCRIPTION OF DRAWINGS The present invention will become more fully understood from the detailed description and accompanying drawings. Other systems, methods, features, and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims wherein: FIG.1 shows the front view of an embodiment of an IOL having an extended depth of focus, according to the embodiments of the present disclosure; FIG.2 shows the surface sag of the first embodiment of the disclosed IOL; FIG.3 shows the through focus Modulation Transfer Function (MTF) of the first embodiment at a 3.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.4 shows the through focus MTF of the first embodiment at a 5.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.5 shows the simulated through focus retinal images of a monofocal IOL from far focus to +3.0 D at 0.5 D intervals; FIG.6 shows the simulated through focus retinal images of the first embodiment at 3.0 mm aperture from far focus to +3.0 D at 0.5 D intervals; FIG.7 shows the simulated through focus retinal images of the first embodiment at 5.0 mm aperture from far focus to +3.0 D at 0.5 D intervals; FIG.8 shows the surface sag of the second embodiment of the disclosed IOL; FIG.9 shows the through focus MTF of the second embodiment at a 3.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.10 shows the through focus MTF of the second embodiment at a 5.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.11 shows the simulated through focus retinal images of the second embodiment at 3.0 mm aperture from far focus to +3.0 D at 0.5 D intervals; FIG.12 shows the surface sag of the third embodiment of the disclosed IOL; FIG.13 shows the through focus MTF of the third embodiment at a 3.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.14 shows the through focus MTF of the third embodiment at a 5.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.15 shows the simulated through focus retinal images of the third embodiment at 3.0 mm aperture from far focus to +3.0 D at 0.5 D intervals; FIG.16 shows the surface sag of the fourth embodiment of the disclosed IOL; FIG.17 shows the through focus MTF of the fourth embodiment at a 3.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); FIG.18 shows the through focus MTF of the fourth embodiment at a 5.0 mm aperture at both 50 and 100 cycles per millimeter (CPMM); and FIG.19 shows the simulated through focus retinal images of the fourth embodiment at 3.0 mm aperture from far focus to +3.0 D at 0.5 D intervals. DETAILED DESCRIPTION OF THE INVENTION The exemplary embodiments relate to ophthalmic devices such as spectacle glasses, IOLs, and contact lenses. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the exemplary embodiments and the generic principles and features described herein will be readily apparent. The exemplary embodiments are mainly described in terms of particular methods and systems provided in particular implementations. However, the methods and systems will operate effectively in other implementations. For example, the method and system are described primarily in terms of IOLs. However, the method and system may be used with contact lenses and spectacle glasses. In the following description, details are set forth by example to facilitate discussion of the disclosed subject matter. It should be apparent to a person of ordinary skill in the field, however, that the disclosed embodiments are exemplary and not exhaustive of all possible embodiments. The present disclosure involves a monofocal ophthalmic lens such as found on spectacle glasses, IOLs, and contact lenses and shown in FIG.1 as IOL lens 10. The lens comprises two zones: first zone 12 about the optical axis and second zone 14 about the first zone extending to edge 16. Both first zone 12, having a radius of R₀, and second zone 14 are symmetrical about the optical axis of the lens. The zones may be found either on the anterior or the posterior surface of lens 10. First zone 12 has a surface sag that applies an odd aspheric axicon wavefront to incoming light that will extend the depth of focus of the monofocal lens. Lens 10 may correct the presbyopia of the wearer under photopic conditions at all distances, and when in mesopic conditions, lens 10 will function as a monofocal lens. As for some background, for a monofocal ophthalmic lens, the wavefront emerging from the lens is essentially a sphere that converges to a single focal point. An even asphere surface is often applied to the lens to correct the spherical aberration from the eye's cornea. However, when a carefully designed OAA surface is applied to either the anterior or the posterior surface of the lens, the monofocal lens is augmented with a considerable depth of focus that can correct the presbyopia of the wearer’s vision. The wearer using such a lens will be able to see clearly for a range of distances, from far to intermediate or near, depending on the prescription. The OAA augmented monofocal lens has an anterior surface and a posterior surface. One of the two surfaces is a normal standard conic or even asphere surface. The other surface is an even asphere surface modified with an OAA surface at its central region. The characteristics of this OAA surface can be defined with the following equation: ே ì ï _{^ ^^^} ^{^} ^ < ^_^ (1)

where: ^(^) is the sagitta of the OAA surface; ^ is the radial coordinate of the lens aperture; ^_^ is the coefficient of the nth order in the odd asphere polynomial; ^ is the highest order of the odd asphere polynomial series, and ^ = 1, 3, ⋯ , ^; and ^_^ is the radius of the aperture of the odd asphere axicon. ^, ^_^ (^ = 1, 3, ⋯ , ^ ), and ^_^ are the specification parameters for a specific design. They are defined in a range of values for viable lens performances. The OAA is intended for small aperture performance. Therefore, ^_^ shall be less than 1.5 mm for the augmentation of photopic performance. The values of ^_^ will determine the augmentation major and magnitude. The following are four embodiments of the invention to demonstrate the performance of the invention. The first embodiment is a first-order axicon with the following parameters: N = 1 R₀ = 1.5 mm A₁ = -5.5000E-03 FIG.2 shows the surface sag of this embodiment where the equivalent convergence power of the axicon is neutralized to zero within the aperture of the first zone. FIG.3 shows the through focus MTF of this embodiment at an aperture of 3.0 mm for the special frequencies of 50 and 100 cycles-per-millimeter (CPMM). FIG.4 shows the through focus MTF of this embodiment at an aperture of 5.0 mm for the special frequencies of 50 and 100 cycles-per-millimeter (CPMM). In FIGs.3 and 4, the 50 CPMM MTF is shown as a solid line, while the 100 CPMM MTF is shown as a dashed line. The peak at 0.0 D is wider for the 3.0 mm aperture lens than for the 5.0 mm aperture lens, indicating a greater depth of focus performance. The through focus MTF for the 5.0 mm aperture lens approaches the through focus MTF for a monofocal lens. Simulations of the first embodiment’s through focus retinal images are shown in FIGs.6 and 7, while FIG.5 shows a simulation of a monofocal through focus retinal image for comparison against the first embodiment and the embodiments that follow. FIG.6 shows the simulation of the through focus retinal image for the 3.0 mm aperture, while FIG.7 shows the simulation of the through focus retinal image for the 5.0 mm aperture. All of the simulations were conducted from far focus (i.e.0.0 D) to +3.0 D at 0.5 D intervals. As seen, the simulation in FIG.6 supports the improved depth of focus performance shown in FIG.3 for the 3.0 mm aperture lens. Additionally, the simulation in FIG.7 supports the monofocal like depth of focus performance shown in FIG.4 for the 5.0 mm aperture lens. As will be seen in the remaining embodiments, the performance of the 5.0 mm aperture lens remains monofocal-like. Therefore, while the through focus MTF will be illustrated in the remaining embodiments for the 5.0 mm aperture lens, the simulation will not. The second embodiment is also a first-order axicon but demonstrates a longer depth of focus than the first embodiment. The second embodiment uses the following parameters: N = 1 R₀ = 1.5 mm A₁ = -9.50E-003 FIG.8 shows the surface sag of this embodiment where the equivalent convergence power of the axicon is neutralized to zero within the aperture of the first zone. FIG.9 shows the through focus MTF of this embodiment at an aperture of 3.0 mm for the special frequencies of 50 and 100 cycles-per-millimeter (CPMM). FIG.10 shows the through focus MTF of this embodiment at an aperture of 5.0 mm for the special frequencies of 50 and 100 cycles-per-millimeter (CPMM). In FIGs.9 and 10, the 50 CPMM MTF is shown as a solid line, while the 100 CPMM MTF is shown as a dashed line. The peak at 0.0 D is wider for the 3.0 mm aperture lens than for the 5.0 mm aperture lens, indicating a greater depth of focus performance over the 5.0 mm aperture lens. It is also seen, comparing FIG.9 with FIG.3, that the depth of focus for the second embodiment is improved over the same for the first embodiment. The through focus MTF for the 5.0 mm aperture lens approaches the through focus MTF for a monofocal lens. A simulation of the second embodiment’s through focus retinal images is shown in FIG.11, while FIG.5 shows a simulation of a monofocal through focus retinal image for comparison. FIG.11 shows the simulation of the through focus retinal image for the 3.0 mm aperture lens from far focus (i.e.0.0 D) to +3.0 D at 0.5 D intervals. As seen, the simulation in FIG.11 supports the improved depth of focus performance shown in FIG.9 for the 3.0 mm aperture lens. The third embodiment is a seventh order axicon that demonstrates a longer depth of focus than the second embodiment. The third embodiment uses the following parameters: N = 7 R₀ = 1.4 mm A₁ = -2.7004E-03 A₃ = 2.1205E-02 A₅ = -4.6919E-03 A₇ = 5.6212E-04 FIG.12 shows the surface sag of this embodiment where the equivalent convergence power of the axicon is neutralized to zero within the aperture of the first zone. FIG.13 shows the through focus MTF of this embodiment at an aperture of 3.0 mm for the special frequencies of 50 and 100 cycles-per-millimeter (CPMM). FIG.14 shows the through focus MTF of this embodiment at an aperture of 5.0 mm for the special frequencies of 50 and 100 cycles-per- millimeter (CPMM). In FIGs.13 and 14, the 50 CPMM MTF is shown as a solid line, while the 100 CPMM MTF is shown as a dashed line. The peak at 0.0 D is wider for the 3.0 mm aperture lens than for the 5.0 mm aperture lens, indicating a greater depth of focus performance over the 5.0 mm aperture lens. It is also seen, comparing FIG.13 with FIGs.3 and 9, that the depth of focus for the third embodiment is improved over the same for the first and second embodiments. The through focus MTF for the 5.0 mm aperture lens approaches the through focus MTF for a monofocal lens. A simulation of the third embodiment’s through focus retinal images is shown in FIG.15, while FIG.5 shows a simulation of a monofocal through focus retinal image for comparison. FIG.15 shows the simulation of the through focus retinal image for the 3.0 mm aperture lens from far focus (i.e.0.0 D) to +3.0 D at 0.5 D intervals. As seen, the simulation in FIG.15 supports the improved depth of focus performance shown in FIG.13 for the 3.0 mm aperture lens. The fourth embodiment is a third order axicon that demonstrates a longer depth of focus than the third embodiment. The fourth embodiment uses the following parameters: N = 3 R₀ = 1.4 mm A₁ = 0 A₃ = 4.50E-03 FIG.16 shows the surface sag of this embodiment where the equivalent convergence power of the axicon is neutralized to zero within the aperture of the first zone. FIG.17 shows the through focus MTF of this embodiment at an aperture of 3.0 mm for the special frequencies of 50 and 100 cycles-per-millimeter (CPMM). FIG.18 shows the through focus MTF of this embodiment at an aperture of 5.0 mm for the special frequencies of 50 and 100 cycles-per- millimeter (CPMM). In FIGs.17 and 18, the 50 CPMM MTF is shown as a solid line, while the 100 CPMM MTF is shown as a dashed line. The peak at 0.0 D is wider for the 3.0 mm aperture lens than for the 5.0 mm aperture lens, indicating a greater depth of focus performance over the 5.0 mm aperture lens. It is also seen, comparing FIG.17 with FIGs.3, 9, and 13, that the depth of focus for the fourth embodiment is improved over the same for the earlier embodiments. The through focus MTF for the 5.0 mm aperture lens approaches the through focus MTF for a monofocal lens. A simulation of the fourth embodiment’s through focus retinal images is shown in FIG.19, while FIG.5 shows a simulation of a monofocal through focus retinal image for comparison. FIG.19 shows the simulation of the through focus retinal image for the 3.0 mm aperture lens from far focus (i.e.0.0 D) to +3.0 D at 0.5 D intervals. As seen, the simulation in FIG.19 supports the improved depth of focus performance shown in FIG.17 for the 3.0 mm aperture lens. Exemplary embodiments of the invention have been disclosed in an illustrative style. Accordingly, the terminology employed throughout should be read in a non-limiting manner. Although minor modifications to the teachings herein will occur to those well versed in the art, it shall be understood that what is intended to be circumscribed within the scope of the patent warranted hereon are all such embodiments that reasonably fall within the scope of the advancement to the art hereby contributed and that that scope shall not be restricted, except in the light of the appended claims and their equivalents.

Claims

CLAIMS What is claimed is: 1. An ophthalmic lens, comprising an optic comprising an anterior surface, a posterior surface, an edge at its periphery, and an optical axis, where at least one of the anterior surface and the posterior surface comprising: a first zone extending from the optical axis to a radial boundary having a surface profile of an odd asphere axicon and a second zone extending from the radial boundary to the edge having a surface profile of an even asphere. 2. The ophthalmic lens of claim 1 wherein the radial boundary is less than 1.5 mm from the optical axis. 3. The ophthalmic lens of claim 1 wherein the sagitta of the optic is: ே ì _^ ^{^} ^ where:

^(^) is the sagitta of the optic; ^ is the distance from the optical axis; ^_^ is the coefficient of the nth order in the odd asphere axicon polynomial; ^ is the highest order of the odd asphere axicon polynomial series, and ^ = 1, 3, ⋯ , ^; and ^_^ is the radius of the aperture of the first zone. 4. The ophthalmic lens of claim 1 wherein the sagitta of the first zone is a first, third, or seventh order odd asphere axicon.