Patent Description:
Intraocular Lenses (IOLs) may be used for restoring visual performance after a cataract or other ophthalmic procedure in which the natural crystalline lens is replaced with or supplemented by implantation of an IOL. When such a procedure changes the optics of the eye, generally a goal is to improve vision in the central field. Recent studies have found that, when a monofocal IOL is implanted, peripheral aberrations are changed, and that these aberrations differ significantly from those of normal, phakic eyes. The predominant change is seen with respect to peripheral astigmatism, which is the main peripheral aberration in the natural eye, followed by sphere, and then higher order aberrations. Such changes may have an impact on overall functional vision, including the ability to drive, the risk of falling, postural stability and/or detection ability.

There are also certain retinal conditions that reduce central vision, such as AMD or a central scotoma. Other diseases may impact central vision, even at a very young age, such as Stargardt disease, Best disease, and inverse retinitis pigmentosa. The visual outcome for patients suffering from these conditions can be improved by improving peripheral vision. Peripheral vision can also be degraded by Glaucoma. Glaucoma affects <NUM>% of the population above the age of <NUM>. Patients with glaucoma gradually lose peripheral vision as a result of damage to the optic nerve. Central vision may get degraded at very late stages of the disease. Significant disabilities in daily life can occur due to glaucoma, including problems with walking, balance, risk of falling and driving. Patients suffering from Glaucoma can benefit from lOLs that improve both central as well as peripheral vision.

<CIT> discloses systems for improving overall vision in patients suffering from a loss of vision in a portion of the retina ( e.g., loss of central vision) by providing symmetric or asymmetric optics with an aspheric surface which redirects and/or focuses light incident on the eye at oblique angles onto a peripheral retinal location. An intraocular lens includes a redirection element (e.g., a prism, a diffractive element, or an optical component with a decentered GRIN profile) configured to direct incident light along a deflected optical axis and to focus an image at a location on the peripheral retina. Optical properties of the intraocular lens can be configured to improve or reduce peripheral errors at the location on the peripheral retina. One or more surfaces of the intraocular lens can be a toric surface, a higher order aspheric surface, an aspheric Zernike surface or a Biconic Zernike surface to reduce optical errors in an image produced at a peripheral retinal location by light incident at oblique angles.

The present invention provides intraocular lenses as recited in the claims.

Patients with central visual field loss caused by e.g. age-related macular degeneration (AMD) rely on their remaining peripheral vision to view objects in the external world. Usually, they develop a preferred retinal locus (PRL), an area on the peripheral retina where the optical image quality is higher than optical image quality at other areas of the retina. They view the PRL either by rotating the eye or the head, thus using eccentric fixation. However, vision at the PRL is much poorer, due to both retinal factors, such as, for example, decreased density of ganglion cells and optical factors, such as, for example, light with the oblique incidence necessary to get to the PRL is degraded by oblique astigmatism and coma. Patients with AMD can receive substantial improvements in vision from refractive correction on their PRL, more so than healthy subjects at similar retinal eccentricity. Patients with Glaucoma who suffer from degraded peripheral visual quality can also benefit from lOLs that improve peripheral optical image quality. Current IOL technologies that are configured to correct refractive errors at the fovea can degrade peripheral optical image quality substantially as compared to the natural lenses. Accordingly, IOLs that can improve image quality at the fovea as well as the peripheral retina can be advantageous.

Various systems, methods and devices disclosed herein are directed towards intraocular lenses (IOLs) including, for example, posterior chamber IOLs, phakic IOLs and piggyback IOLs, which are configured to improve peripheral vision. For normal patients, e.g., uncomplicated cataract patients, peripheral vision may be balanced with good central vision in order to improve or maximize overall functional vision. For those patients having a pathological loss of central vision, peripheral vision may be improved or maximized for field angles <NUM>-<NUM> degrees with respect to the optic axis. For some patients, peripheral vision may be improved or maximized by taking into account the visual angle where the retina is healthy.

The systems, methods and devices may be better understood from the following detailed description when read in conjunction with the accompanying schematic drawings, which are for illustrative purposes only. The drawings include the following figures:.

Patients suffering from AMD experience loss of central vision and rely on their peripheral vision to view objects in their environment. One way to aid patients with AMD currently is through the use of magnification. Magnification is usually accomplished by a high power loupe or telescope. Magnification can be achieved with implantable telescopes in one or both eyes. For example, a two-lens system can be employed to provide magnification for AMD patients. As another example, a lens system comprising a Lipshitz mirror telescope can be employed to provide magnification for AMD patients. However, the current solutions may not be configured to correct refractive errors at the fovea or at the peripheral retinal locations. Solutions for AMD patients can benefit from increasing visual quality at peripheral retinal location.

Glaucoma affects <NUM>% of the population above age <NUM> and prevalence increases with age. Patients suffering from Glaucoma gradually lose peripheral vision as a result of damage to the optic nerve. As Glaucoma progresses, the central vision also gets affected. Glaucoma is usually diagnosed through a variety of methods including measuring intraocular pressure (IOP) and/or performing visual field tests (perimetry). Accordingly, IOLs visual field tests are configured to measure visual acuity for a variety of visual field angles between -<NUM> degrees to <NUM> degrees. Patients suffering from Glaucoma gradually lose peripheral vision. Accordingly, Glaucoma patients can benefit from optical solutions that increase visual quality for peripheral vision.

Various IOLs that are currently available in the market while configured to provide good visual acuity for central vision can introduce refractive errors (e.g., defocus and/or astigmatism) in the peripheral vision. Accordingly, IOLs that can reduce peripheral refractive errors while also providing maintaining or increasing image quality at the fovea can be beneficial to patients with Glaucoma who may or may not suffer also from cataract. IOL designs that can reduce these peripheral refractive errors can have several benefits including but not limited to the following:.

Various IOL designs configured to improve peripheral image quality are described in<CIT> published as <CIT>. Various IOL designs configured to improve peripheral image quality for patients with AMD are described in <CIT>, Published as <CIT>); <CIT>, Published as <CIT>); <CIT>, Published as <CIT>); <CIT>) and <CIT>, Published as <CIT>).

Various IOLs configured to improve image quality at one or more peripheral retinal locations can comprise at least one of redirection elements, refractive index gradient, multi-refraction elements, asymmetric Zernike surfaces or Fresnel diffractive elements. The shape factor of the lOLs can be modified to correct errors in the peripheral retinal location. Furthermore, IOLs configured to improve image quality at one or more peripheral retinal locations can be both symmetric (improving the peripheral field in all locations) and asymmetric (improving the area around the PRL).

Various IOLs configured to improve image quality at one or more peripheral retinal locations can comprise piggyback lenses that can improve peripheral MTF using thin and thick designs to reduce peripheral refractive errors, astigmatism, coma and other optical errors. Various IOLs configured to improve image quality at one or more peripheral retinal locations can comprise toric, aspheric, higher order aspheric, Zernike and biconic surfaces, overlaid on meniscus designs. Various lOLs configured to improve image quality at one or more peripheral retinal locations can comprise piggyback lenses with Fresnel surfaces. The principal plane of an existing IOL can be displaced to improve image quality at one or more peripheral retinal locations.

IOLs that are configured to improve image quality at one or more peripheral retinal locations can be configured to correcting astigmatism and coma that arise from oblique incidence. In addition to correcting astigmatism and coma arising from oblique incidence of light, it is advantageous to provide IOLs that can correct longitudinal chromatic aberrations to improve image quality at one or more peripheral retinal locations. Correcting longitudinal chromatic aberrations in addition to correcting astigmatism and coma that arise from oblique incidence of light can further improve image quality at peripheral retinal locations.

Various embodiments according to the invention comprise an IOL including an achromatic optical element. For example, an IOL configured to correct peripheral aberrations through the use of shape factor, displacement and correct balancing of higher order aberrations is combined with an achromatic optical element or an achromatic surface optimized for the power of the IOL. The achromatic surface is disposed on the side of the IOL that has a lower slope. The achromatic surface is disposed on the anterior side that is configured to receive incident light which has a lower slope rather than the posterior side.

Various embodiments of IOLs disclosed herein are configured to correct peripheral refractive errors for visual field angles up to +<NUM>-degrees. At least one of a shape factor, a placement of the IOL in the eye, curvature and/or asphericity of the surfaces of the IOL disclosed herein can be adjusted such that residual peripheral refractive errors for visual field angles up to +<NUM>-degrees when the IOL is implanted in the eye is less than a threshold amount. IOLs according to the invention disclosed herein include an achromatic optical element. For example, an IOL configured to correct peripheral aberrations through the use of shape factor, displacement and balancing of higher order aberrations is combined with an achromatic optical element or an achromatic surface optimized for the power of the IOL.

Various embodiments of lOLs according to the invention, configured to improve image quality at one or more peripheral retinal locations comprise a meniscus lens in which both the anterior and posterior surfaces are aspheric (also referred to as Double Asphere Design (DAD)). To improve the image quality at one or more peripheral retinal locations, the meniscus lens can be implanted such that the principal plane of the lens is displaced by an amount such as, for example about <NUM> and about <NUM> posteriorly from the iris as compared to the position where a standard intraocular lens (e.g., a meniscus IOL) is implanted. In various embodiments, the meniscus lens can have a negative shape factor, wherein the first surface is concave and the second surface is convex. To correct longitudinal chromatic aberrations, a meniscus lens having a first surface that is concave and a second surface that is convex includes an achromatic surface placed on the anterior part that is flatter (or has a lower slope) as compared to the posterior surface. The meniscus (e.g., double asphere design) lens including an achromatic surface can comprise:.

Various IOLs configured to improve image quality at one or more peripheral retinal locations can comprise a biconvex design (also referred to as BOSS herein) in which both the anterior and the posterior surfaces have similar curvatures. The anterior and the posterior surfaces can be aspheric. IOLs having biconvex lens designs can be implanted such that the principal plane of the lens is displaced by an amount such as, for example about <NUM> and about <NUM> posteriorly from the iris as compared to the position where a standard IOL (e.g., a biconvex lens design) is implanted. The biconvex lens can have a shape factor close to zero, and a thickness between about <NUM> and about <NUM>. In lOLs with biconvex design, the achromatic surface can be placed on the anterior side or the posterior side, since both the anterior and posterior surface can have similar curvature in most practical implementations.

Various biconvex lens designs are illustrated in Figures <NUM>-<NUM> in <CIT>.

The achromatic optical element or surface integrated with the meniscus lens design (e.g., double aspheric lens design) or the biconvex lens design can comprise:.

<FIG> illustrates a meniscus IOL <NUM> that is configured to be implanted in the eye of a patient. The IOL <NUM> has an anterior surface <NUM> and a posterior surface <NUM> opposite the anterior surface. The anterior and the posterior surface are intersected by an optical axis <NUM>. The thickness of the IOL <NUM> along the optical axis <NUM> can be between about <NUM> and about <NUM>. For example, the thickness of the IOL <NUM> along the optical axis <NUM> can be between about <NUM> and about <NUM>. between about <NUM> and about <NUM>, between about <NUM> and about <NUM>, or any value in between these values. The IOL <NUM> can be configured to improve image quality at one or more locations of the peripheral retinal through the use of shape factor, displacement of the principal plane and correction of higher order aberrations.

It is noted from <FIG>, that the anterior surface <NUM> of the IOL <NUM> is nearly flat. Furthermore, the anterior surface <NUM> has a curvature (or slope) that is less than a curvature (or slope) of the posterior surface <NUM>. An IOL having an anterior surface <NUM> that is nearly flat can have several benefits. For example, an anterior surface that is nearly flat can be less sensitive to eccentricity between anterior and posterior surfaces. As another example, a nearly flat anterior surface can make the addition of an achromatic element or surface to function more effectively.

<FIG> illustrates a portion of an achromatic element integrated with an anterior surface of the meniscus lens depicted in <FIG> according to an embodiment of the invention. As discussed above, an achromatic element having a surface profile as depicted in <FIG> is combined with an IOL similar to the IOL <NUM> depicted in <FIG> to improve image quality in one or more peripheral retinal locations. The achromatic element disposed on the side of the IOL that has a lower slope. For example, the achromatic element having a surface profile as depicted in <FIG> is disposed on the nearly flat anterior surface <NUM> of the IOL <NUM> depicted in <FIG>.

<FIG> illustrates the percentage modulus of the optical transfer function (MTF) improvement over the a standard intraocular lens (ZCB) at half the neural limit spatial frequency as a function of the angle of the peripheral retinal location with respect to the optical axis for a meniscus lens comprising an achromatic element and a meniscus lens without an achromatic element. The peripheral retinal location can have an eccentricity between -<NUM> degrees and <NUM> degrees with respect to the optical axis. In various implementations, the peripheral retinal location can have an eccentricity between about -<NUM> degrees and <NUM> degrees, between about -<NUM> degrees and <NUM> degrees, between about -<NUM> degrees and <NUM> degrees, or values therebetween. The angular ranges for eccentricity of the peripheral retinal location refer to the visual field angle in object space between an object with a corresponding retinal image on the fovea and an object with a corresponding retinal image on a peripheral retinal location. It can be seen that adding the achromat substantially improves the contrast in the central region, which is beneficial for patients maintaining some residues of central visual performance, while simultaneously keeping the good peripheral performance for the meniscus lens design with an achromat.

The achromatic optical element or achromatic surface is disposed on the less curved side. As discussed above, an advantage of introducing the achromatic optical element or achromatic surface comes from improved central visual performance, while still maintaining the good peripheral vision. The advantage of disposing the achromatic optical element or the achromatic surface on the less curved surface is observed from the figures below.

<FIG> illustrates polychromatic MTF for a meniscus lens without an achromatic element at the fovea. <FIG> illustrates polychromatic MTF for a meniscus lens having an achromatic element integrated with the anterior surface of the meniscus lens at the fovea.

Several lenses according to the above described principles were manufactured and their performance measured in physical eye models. Examples of measured performance are depicted in <FIG>. <FIG> illustrates on-axis MTF versus spatial frequency for a <NUM> pupil in polychromatic light for a double aspheric lens (e. g, both the posterior and anterior surfaces are aspheric) having an achromatic element integrated with its anterior surface (curve <NUM>) and a double aspheric lens without an achromatic element (curve <NUM>). The on-axis MTF for double aspheric lens with an achromatic optical element disposed on the anterior surface is greater than the corresponding on-axis MTF for double aspheric lens without an achromatic optical element for spattial frequency greater than <NUM> cycles/mm indicating improved foveal vision for the double aspheric lens with an achromatic optical element disposed on the anterior surface as compared to the double aspheric lens without an achromatic optical element.

<FIG> illustrates on-axis MTF versus spatial frequency for a <NUM> pupil in polychromatic light a double aspheric lens having an achromatic element integrated with its anterior surface (curve <NUM>) and a double aspheric lens without an achromatic element (curve <NUM>). Similar to the <NUM> pupil condition, the on-axis MTF for double aspheric lens with an achromatic optical element disposed on the anterior surface is greater than the corresponding on-axis MTF for double aspheric lens without an achromatic optical element for spatial frequency greater than <NUM> cycles/mm indicating improved foveal vision for the double aspheric lens with an achromatic optical element disposed on the anterior surface as compared to the double aspheric lens without an achromatic optical element. Similar measurements are performed with a biconvex design (BOSS) in which the anterior and posterior surfaces have approximate similar curvatures, which are shown below in <FIG>. With reference to <FIG>, curves <NUM> and <NUM> on-axis MTF versus spatial frequency for a <NUM> pupil and <NUM> pupil respectively in polychromatic light for a biconvex lens having an achromatic element integrated with its anterior surface. With reference to <FIG>, curves <NUM> and <NUM> on-axis MTF versus spatial frequency for a <NUM> pupil and <NUM> pupil respectively in polychromatic light for a biconvex lens without an achromatic element. It is noted that on-axis MTF for a biconvex lens with an achromatic optical element disposed on the anterior surface is greater than the corresponding on-axis MTF for a biconvex lens without an achromatic optical element for spatial frequency greater than <NUM> cycles/mm for both <NUM> and <NUM> pupil indicating improved foveal vision for the biconvex lens with an achromatic optical element disposed on the anterior surface as compared to the biconvex lens without an achromatic optical element.

It is noted that for both <NUM> pupil condition and <NUM> pupil condition, the achromat optical element enhances optical performance for spatial frequencies above <NUM> cycles per mm, which is often used to illustrate on-axis performance. The on-axis best focus MTF for a spatial frequency of <NUM> cycles/mm for the meniscus lens with and without achromat optical element for <NUM> pupil condition and <NUM> pupil condition is shown in <FIG> respectively. Referring to <FIG>, block <NUM> illustrates the on-axis best focus MTF for a spatial frequency of <NUM> cycles/mm for the meniscus lens with an achromat optical element for the <NUM> pupil condition and block <NUM> illustrates the on-axis best focus MTF for a spatial frequency of <NUM> cycles/mm for the meniscus lens without an achromat optical element for the <NUM> pupil condition. Referring to <FIG>, block <NUM> illustrates the on-axis best focus MTF for a spatial frequency of <NUM> cycles/mm for the meniscus lens with an achromat optical element for the <NUM> pupil condition and block <NUM> illustrates the on-axis best focus MTF for a spatial frequency of <NUM> cycles/mm for the meniscus lens without an achromat optical element for the <NUM> pupil condition. It is noted that for both pupil conditions, the optical performance for the meniscus lens with achromatic optical element is better than the optical performance for the meniscus lens without achromatic optical element.

<FIG> illustrates on-axis MTF for a spatial frequency of <NUM> cycles/mm for a <NUM> pupil in polychromatic light for a biconvex lens comprising an achromatic element (block <NUM>) and a biconvex lens without an achromatic element (block <NUM>). <FIG> illustrates on-axis MTF for a spatial frequency of <NUM> cycles/mm for a <NUM> pupil in polychromatic light for a biconvex lens comprising an achromatic element (block <NUM>) and a biconvex lens without an achromatic element (block <NUM>). It is noted that for both pupil conditions, the optical performance for the biconvex lens with achromatic optical element is better than the optical performance for the biconvex lens without achromatic optical element.

In addition to substantial reduction in off-axis aberrations, such as, for example, oblique astigmatism, the surface geometries of the anterior and posteriors surfaces of the Double Aspheric Design (DAD) IOL can be configured to maintain on-axis image quality similar to existing monofocal IOLs that are configured to provide foveal vision. IOLs (e.g., DAD IOLs) described herein can have a central axial thickness that is greater than the central axial thickness of existing monofocal IOLs that are configured to provide foveal vision. For example, IOLs described herein can have a central thickness of about <NUM>. As another example, IOLs described herein can have a central thickness greater than <NUM> and less than <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, or any value in these ranges/sub-ranges. The IOLs discussed herein (e.g., DAD IOL) can be vaulted when placed in the eye of the patient. For example, IOLs described herein can be vaulted by about <NUM> towards the retina as compared to existing monofocal IOLs that are configured to provide foveal vision. As another example, IOLs described herein can be vaulted towards the retina by a distance between about <NUM> and about <NUM> as compared to existing monofocal IOLs that are configured to provide foveal vision. The vault distance can be greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, greater than or equal to about <NUM> and less than or equal to about <NUM>, or any value in these ranges/sub-ranges.

DAD IOLs that can be used for cataract patients with or at risk for Age-related Macular Degeneration (AMD) and/or Glaucoma can comprise aspheric anterior and posterior surfaces. DAD IOLs contemplated herein can be configured to provide good optical quality at the fovea as well at a location of the peripheral retina. Good optical quality at the location of the peripheral retina can be achieved by optimizing the surface geometries of the anterior and posterior surfaces of the IOL, by adjusting the central axial thickness of the IOL and/or by optimizing the distance of the anterior surface of the IOL from the iris. Currently, about <NUM>% of patients undergoing cataract surgery have some form of AMD. Patients with AMD eventually lose their central vision, leaving only their peripheral vision. Therefore, IOLs configured to provide high image quality in the peripheral visual field, while simultaneously maintaining sufficient contrast ratio for central vision (also referred to herein as foveal vision), so that any remaining central vision can be used as long as possible are desirable. However, IOLs available commercially can exacerbate peripheral optical errors. Since patients with AMD can have their vision improved by correction of optical errors in the periphery, correction of peripheral optical errors represent an area of potentially improved visual quality of life.

Without subscribing to any particular theory, the anterior and posterior surface sag Z of DAD IOLs can be obtained from equation (<NUM>): <MAT> where r is the radial distance from the center of the lens, c is the curvature, k is the conic constant and a4, a6, a8, and a10 are the higher order aspheric terms.

The values of the central thickness and vault height for DAD IOLs can be selected keeping in view the following factors: (i) optical performance - IOLs with increased central thickness and higher vault height have increased optical performance; (ii) mechanical stability - which places an upper limit on vault height; (iii) ease of insertion in a human eye - smaller incision size (e.g., about <NUM>) is desirable which places a condition on central thickness; and (iv) functional optical zone size - increased central thickness of the IOL can provide an increase functional optical zone, which can desirable for AMD patients, many of who exhibit enlarged pupils. An example of a DAD IOL optimized based on the factors discussed above can have a vault height of about <NUM>, a central thickness of <NUM> and a functional optic zone of about <NUM>. Another example of a DAD IOL optimized to provide good foveal as well as peripheral visual quality can have a vault height between about <NUM> and about <NUM>, a central thickness between about <NUM> and about <NUM> and a functional optic zone having a size between about <NUM> and about <NUM> (e.g., a functional optic zone having a size of about <NUM>, or a functional optic zone having a size of about <NUM>).

Table <NUM> below provides the values of the coefficients that define the anterior and posterior surface of various DAD IOLs having optical power from about <NUM> D to about <NUM> D. In Table <NUM>, column A is the optical power in Diopters for various DAD IOLs, column B indicates one of an anterior (Ant. ) or a posterior (Post. ) surface for various DAD IOLs, column C is the central thickness in mm for various DAD IOLs, column D is the vault height (towards the retina) in mm for various DAD IOLs, column E is the radius of curvature of the respective surface (Ant. ) for various DAD IOLs, column F is the conic constant k used to design the respective surface (Ant. ) for various DAD IOLs, columns G, H and I are the higher order aspheric terms a4, a6, a8 and a10 used to design the respective surface (Ant. ) for various DAD IOLs. For any given optical power, it is envisioned that specific IOLS include variations in any value in columns C through J of up to about <NUM>%, or preferably up to about <NUM>%, or up to about <NUM>%. The range of optical powers can be between 5D and 40D, or preferably between from about 18D to about 30D, or between about 21D and about 27D.

The performance of a DAD IOL is compared with an existing monofocal IOL that is configured to provide good on-axis image quality. The comparison of the performance of the DAD IOL and the existing monofocal IOL was based on the following three metrics: on-axis MTF, off-axis astigmatism and simulated peripheral VA.

<FIG> illustrate the comparison of on-axis modulus transfer function (MTF) for a DAD IOL and an existing monofocal IOL (referred to herein as ZCB) that is configured to provide good on-axis image quality. The on-axis MTF was obtained with a <NUM> entrance pupil for green and white light respectively. Referring to <FIG>, curve <NUM> illustrates the on-axis MTF for the ZCB lens and curve <NUM> illustrates the on-axis MTF for the DAD IOL. Referring to <FIG>, curve <NUM> illustrates the on-axis MTF for the ZCB lens and curve <NUM> illustrates the on-axis MTF for the redesigned DAD IOL. The on- axis MTF performance of the DAD IOL is comparable (e.g., substantially identical) to the on-axis MTF performance of the ZCB lens.

<FIG> illustrate the comparison of on-axis modulus transfer function (MTF) for a DAD IOL and the ZCB lens. The on-axis MTF was obtained with a <NUM> entrance pupil for green and white light respectively. Referring to <FIG>, curve <NUM> illustrates the on-axis MTF for the ZCB lens and curve <NUM> illustrates the on-axis MTF for the DAD IOL. Referring to <FIG>, curve <NUM> illustrates the on-axis MTF for the ZCB lens and curve <NUM> illustrates the on-axis MTF for the DAD IOL. The on-axis MTF performance of the DAD IOL is comparable (e.g., substantially identical) to the on-axis MTF performance of the ZCB lens.

Simulated off-axis astigmatism is depicted in <FIG> A is a graph depicting the simulated off-axis astigmatism for two different lOLs at visual field angles of <NUM> degrees and <NUM> degrees. In <FIG>, bar <NUM> is the off-axis astigmatic power of the ZCB lens at a visual field angle of about <NUM> degrees, bar <NUM> is the off-axis astigmatic power of the DAD IOL at a visual field angle of about <NUM> degrees, bar <NUM> is the off-axis astigmatic power of the ZCB lens at a visual field angle of about <NUM> degrees, and bar <NUM> is the off-axis astigmatic power of the DAD IOL at a visual field angle of about <NUM> degrees. It is noted from <FIG>, that the DAD IOL in conjunction with the human visual system (including the optics of the cornea of an average eye) provides a residual peripheral astigmatism less than about <NUM> Diopter at visual field angles of <NUM> degrees and <NUM> degrees. It is further noted is that the residual peripheral astigmatism provided by the combination of the DAD IOL along with the human visual system (including the optics of the cornea of an average eye) is about half the residual peripheral astigmatism provided by the combination of the ZCB lens along with the human visual system (including the optics of the cornea of an average eye). Without subscribing to any particular theory, the residual peripheral astigmatism is a difference in diopters between tangential and sagittal peaks which is referred to optometrists as 'C.

Although the peripheral astigmatism is one of the sources of off-axis aberration, it does not fully describe peripheral off-axis image quality. Other peripheral aberrations such as peripheral defocus, coma, and other higher order aberrations can also degrade image quality. Therefore, a metric that relies on the area under the MTF for spatial frequencies up to the neurally relevant cutoff is used to characterize peripheral visual quality. The area under the MTF can be correlated with on-axis visual acuity. The area is then converted to an equivalent diopter value, which is converted to a VA loss score in logMAR with a factor of <NUM>. <FIG> IB is a graph depicting the visual acuity gain for the ZCB IOL (represented by curve <NUM>) and a DAD IOL (represented by curve <NUM>) for different visual field angles. It is observed that the DAD IOL (represented by curve <NUM>) has a visual acuity gain of about <NUM> over the ZCB IOL at a visual field angle of about <NUM> degrees and a visual acuity gain of about <NUM> over the ZCB IOL at a visual field angle of about <NUM> degrees. Accordingly, an AMD patient can have considerable improvement in visual image quality at a peripheral retinal location when implanted with the DAD IOL as compared to when implanted with the ZCB lens. Additionally, the DAD IOL can have reduced anterior surface reflectivity.

As discussed herein, correction of peripheral refractive errors and/or aberrations can improve peripheral vision. For example, patients with AMD can benefit by correction of peripheral refractive errors and/or aberrations. <FIG> show a comparison of the mean sphere, cylinder, spherical aberration and total higher order root mean square errors for the ZCB lens (represented by solid blocks) and a DAD IOL (represented by hatched blocks) as a function of visual angle. It is noted from <FIG> that the DAD IOL (represented by hatched blocks) has reduced values of mean sphere and the cylinder at visual angles corresponding to <NUM>, <NUM> and <NUM> degrees as compared to the ZCBIOL (represented by solid blocks). From <FIG> it is observed that the central as well as peripheral spherical aberration (at visual angles corresponding to <NUM>, <NUM> and <NUM> degrees) for the DAD IOL (represented by hatched blocks) is substantially similar to the central as well as peripheral spherical aberration (at visual angles corresponding to <NUM>, <NUM> and <NUM> degrees) for the ZCB IOL. It is noted from <FIG> that the total higher order root mean square errors for the ZCB IOL at visual angles corresponding to <NUM>, <NUM> and <NUM> degrees is higher than the total higher order root mean square errors for the DAD IOL at visual angles corresponding to <NUM>, <NUM> and <NUM> degrees. The total higher order root mean square errors for the ZCB IOL for central vision is comparable to the total higher order root mean square errors for the DAD IOL.

Thus, compared to an existing monofocal IOL that is configured to provide good on-axis image quality (referred to herein as a ZCB IOL), the DAD IOL can give superior off-axis performance, while maintaining equal on-axis performance. The DAD IOLs discussed herein can be configured to have increased tolerance to a large number of surgery dependent variables as well as population variables. The design principles discussed herein can also be used to design and manufacture an intraocular lens that provides visual acuity for foveal vision (or central vision) as well as peripheral vision (e.g., for visual field angles upto <NUM> degrees) similar to the lOLs described in <CIT> titled "Intraocular Lenses with Improved Central and Peripheral Vision".

<FIG> illustrates an IOL <NUM> that is configured to provide good foveal vision as well as good peripheral vision. Such IOLs can be used for patients suffering from Glaucoma and/or AMD. The IOL <NUM> has an anterior surface <NUM> and a posterior surface <NUM>. The anterior and posterior surfaces <NUM> and <NUM> are intersected by an optical axis <NUM>. The IOL <NUM> has a meniscus- biconvex design. The IOL <NUM> can be configured to have a double aspheric design (DAD). Accordingly, various characteristics/parameters of the IOL <NUM> can be similar to the DAD IOLs discussed above. Additionally, the DAD IOLs discussed above can have characteristics/parameters similar to the IOL <NUM> discussed below.

The IOL <NUM> can be configured such that the posterior surface <NUM> is configured to provide most of the refractive power and the anterior surface <NUM> is configured to correct for the spherical aberration introduced by the posterior surface <NUM>. In the IOL <NUM> the anterior surface <NUM> and/or the posterior surface <NUM> can be aspheric. In such IOLs, the asphericity of the posterior surface <NUM> can be configured to introduce a significant amount of spherical aberration in the posterior surface. For example, the posterior surface <NUM> can be configured to have spherical aberration in the range between about <NUM> and <NUM> (e.g., <NUM>). Accordingly, the anterior surface <NUM> can be configured to have a negative spherical aberration in the range between about -<NUM> and -<NUM>µmη to correct for the spherical aberration introduced by the posterior surface <NUM> such that the total residual spherical aberration introduced by the IOL <NUM> for a normal population of eyes is in the range between <NUM> and -<NUM> for a <NUM> pupil. The apshericity of the anterior surface <NUM> that corrects the spherical aberration introduced by the posterior surface <NUM> can have a great impact on peripheral image quality. For example, the asphericity of the positive surface <NUM> and the anterior surface <NUM> can be adjusted such that the average value for the total residual spherical aberration introduced by the IOL <NUM> for a normal population of eyes can be less than about <NUM> for a <NUM> pupil.

The IOL <NUM> can be configured to have a shape factor between -<NUM> and - <NUM>. For example, the shape factor of the IOL <NUM> can be less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>; less than or equal to -<NUM> and greater than -<NUM>. The shape factor of the IOL <NUM> can be adjusted by adjusting a variety of parameters including but not limited to vault height of the IOL <NUM>, placement of the IOL <NUM> in the eye, thickness of the IOL <NUM> along the optical axis <NUM>, curvature of the posterior and anterior surfaces of the IOL <NUM> and/or asphericity of the posterior and anterior surfaces of the IOL <NUM>. The vault height of the IOL <NUM> can be increased by an amount between <NUM> and about <NUM> as compared to standard IOLs. As discussed above, the IOL <NUM> can be vaulted posteriorly towards the retina by a distance between about <NUM> and about <NUM> as compared to standard IOLs. For example, the IOL <NUM> can be implanted such that the principal plane of the IOL <NUM> is displaced by an amount such as, for example about <NUM> and about <NUM> posteriorly from the iris as compared to the position where a standard intraocular lens (e.g., a meniscus IOL) is implanted. As another example, the IOL <NUM> can be implanted such that the principal plane of the IOL <NUM> is displaced by a distance of about <NUM> posteriorly from the iris as compared to the position where a standard intraocular lens is implanted. Vaulting the IOL <NUM> posteriorly towards the retina can result in a shift of the principal plane of the IOL <NUM> posteriorly.

It is noted that the shift of the principal plane for the IOL <NUM> can be achieved by a variety of methods including but not limited to distributing the refractive power such that a majority of the refractive power is provided by the posterior surface, physically shifting the position of the IOL <NUM> and/or increase in thickness of the IOL <NUM>. The IOL <NUM> can have a thickness that is about <NUM> to about <NUM> thicker than thickness of standard IOLs. For example, as discussed above, the central thickness of the IOL <NUM> can be in the range between about <NUM> and about <NUM>.

As discussed above, the curvature of the posterior surface <NUM> of the IOL <NUM> is configured such that the posterior surface <NUM> contributes more to the total refractive optical power provided by the IOL <NUM> than the anterior surface <NUM>. For example, the curvature of the posterior surface <NUM> can be configured to provide an optical power between about -<NUM> Diopter and +<NUM> Diopter. The curvature of the posterior surface <NUM> and the anterior surface <NUM> of the IOL <NUM> can be configured such that the IOL <NUM> has a shape factor between -<NUM> and -<NUM>. The IOL <NUM> when implanted in a normal human eye can provide a residual peripheral astigmatism less than about <NUM> Diopter at a visual field angle of about <NUM> degrees as compared to a residual peripheral astigmatism of about <NUM> Diopter at a visual field angle of about <NUM> degrees provided by a standard IOL currently available in the market when implanted in the normal human eye. Without subscribing to any particular theory, the residual peripheral astigmatism is a difference in diopters between tangential and sagittal peaks which is referred to optometrists as 'C. As another example, the IOL <NUM> when implanted in a normal human eye can provide a residual peripheral defocus less than about <NUM> Diopter at a visual field angle of about <NUM> degrees as compared to a residual peripheral defocus of about <NUM> Diopter at a visual field angle of about <NUM> degrees provided by a standard IOL currently available in the market when implanted in the normal human eye.

<FIG> illustrate various figures of merit for a standard intraocular lens and an IOL <NUM> (such as, for example an IOL having a shape factor between -<NUM> and - <NUM>) configured to provide improved peripheral vision as well as improved foveal vision. The figures of merit were obtained by performing ray tracing simulations using eye models (e.g., <NUM> realistic eye models) implanted with either lenses representing a standard IOL (e.g., an aspheric standard IOL having a shape factor of about <NUM> and implanted such that the principal plane is about <NUM> behind the iris) and with an IOL <NUM> (e.g., a meniscus lens having a shape factor of about -<NUM> and implanted such that the principal plane is about <NUM> behind the iris).

<FIG> illustrates the peripheral defocus (M) for an IOL <NUM> and a standard IOL as a function of eccentricity. <FIG> illustrates the residual peripheral astigmatism provided by an IOL <NUM> in combination with a human visual system (including the optics of the cornea of an average eye) and a standard IOL in combination with a human visual system (including the optics of the cornea of an average eye) as a function of eccentricity. <FIG> illustrates the spherical aberration (SA) for an IOL <NUM> and a standard IOL as a function of eccentricity. <FIG> illustrates the horizontal coma for an IOL <NUM> and a standard IOL as a function of eccentricity. <FIG> illustrates the total root mean square (RMS) for an IOL <NUM> and a standard IOL as a function of eccentricity. It is noted that the IOL <NUM> has spherical aberration, and overall foveal image quality, similar to the standard IOL. The magnitude of peripheral coma of the IOL <NUM> is approximately similar to the standard IOL, but has the opposite sign. However, peripheral defocus and residual peripheral astigmatism for visual field angles up to +<NUM>-degrees is significantly reduced for the IOL <NUM> as compared to the standard IOL.

The IOL <NUM> can have optical characteristics similar to optical characteristic of other lens designs that are configured to improve peripheral image quality described in <CIT> published as <CIT>. The Glaucoma IOL can be configured as a dual-optic IOL or a piggyback IOL. The IOL <NUM> can be configured as a meniscus lens, a biconvex lens, a plano-convex lens or any other possible shape. The IOL <NUM> described herein can be combined with or replace one or more IOL designs configured to improve peripheral image quality for patients with AMD that are described in <CIT>, Published as <CIT>); <CIT>, Published as <CIT>); <CIT>, Published as <CIT>); <CIT>) and <CIT>, Published as <CIT>).

An example method of designing an IOL to correct for peripheral refractive errors is illustrated in <FIG>. The method <NUM> includes receiving ocular measurements for a patient as shown in block <NUM>. The ocular measurements can be obtained by an ophthalmologist using instruments such as a COAS or a biometer which are currently available in ophthalmology practice. The ocular measurements can include axial length of the eye, corneal power, refractive power that provides visual acuity for central vision, intraocular pressure, peripheral refractive errors measured by a visual fields test and any other measurements that can be used to characterize a patient's visual acuity for field angles upto +<NUM>- degrees. The ocular measurements can include obtaining the variation of the peripheral astigmatism, horizontal coma and spherical optical power as a function of visual field angle.

An initial shape factor of an IOL that provides good visual acuity for central vision is determined as shown in block <NUM>. The initial shape factor can be similar to the shape factor of an appropriate standard IOL currently available that would provide good foveal vision for the patient. The initial shape factor can be iteratively adjusted to optimize peripheral refractive errors for visual field angles upto +<NUM>- degrees without significantly decreasing visual acuity for central vision to determine a final shape factor as shown in block <NUM>. Adjusting the initial shape factor can include adjusting a curvature of the surfaces of the IOL, adjusting the asphericity of the surfaces of the IOL, adjusting a central thickness of the IOL, adjusting a placement of the IOL in the eye. The final shape factor can be determined by placing a model of the IOL having the initial shape factor in a model eye and adjusting one or more parameters (e.g., thickness, curvature and/or asphericity of the surfaces, shape, etc.) of the model IOL till residual peripheral errors (e.g., defocus and astigmatism) for visual field angles upto +<NUM>- degrees are below a threshold value. For example, the determined final shape factor of the IOL can provide a residual peripheral astigmatism less than <NUM> Diopter at a visual field angle of about <NUM> degrees as compared to a residual peripheral astigmatism of about <NUM> Diopter at a visual field angle of about <NUM> degrees provided by a lens having the initial shape factor. As another example, the determined final shape factor of the IOL can provide a residual peripheral defocus less than <NUM> Diopter at a visual field angle of about <NUM> degrees as compared to a residual peripheral defocus of about <NUM> Diopter at a visual field angle of about <NUM> degrees provided by a lens having the initial shape factor.

Peripheral astigmatism can be independent of the patient's biometric inputs. Accordingly, the determination of the final shape factor of the IOL that results in an optical power distribution that corrects for peripheral astigmatism can be independent of the patient's biometric inputs. The final shape factor of the IOL can be configured to correct peripheral astigmatism by providing additional cylinder power that compensates for peripheral astigmatism only at certain specific visual field angles (e.g., +<NUM> degrees, +<NUM> degrees, +<NUM> degrees, +<NUM> degrees). Alternatively, the final shape factor of the IOL can be configured to correct peripheral astigmatism by providing additional cylinder power that compensates for peripheral astigmatism at all visual field angles in an angular range (e.g., between +<NUM> degrees, between +<NUM> degrees, between +<NUM> degrees, between +<NUM> degrees). The final shape factor of the IOL can be configured to correct defocus only at certain specific visual field angles (e.g., +<NUM> degrees, +<NUM> degrees, +<NUM> degrees, +<NUM> degrees). Alternatively, the final shape factor of the IOL can be configured to correct defocus at all visual field angles in an angular range (e.g., between +<NUM> degrees, between +<NUM> degrees, between +<NUM> degrees, between +<NUM> degrees).

The method of designing an IOL to correct for peripheral refractive errors can be implemented by a computer system <NUM> illustrated in <FIG>. The system includes a processor <NUM> and a computer readable memory <NUM> coupled to the processor <NUM>. The computer readable memory <NUM> has stored therein an array of ordered values <NUM> and sequences of instructions <NUM> which, when executed by the processor <NUM>, cause the processor <NUM> to perform certain functions or execute certain modules. For example, a module can be executed that is configured to selecting an ophthalmic lens or an optical power thereof that would provide visual acuity for central vision and iteratively adjust various parameters of the lens that would reduce peripheral refractive errors including but not limited to defocus and astigmatism.

The array of ordered values <NUM> may comprise, for example, one or more ocular dimensions of an eye or plurality of eyes from a database, a desired refractive outcome, parameters of an eye model based on one or more characteristics of at least one eye, and data related to an IOL or set of IOLs such as a power, an aspheric profile, and/or a lens plane. The sequence of instructions <NUM> includes determining a position of an IOL, performing one or more calculations to determine a predicted refractive outcome based on an eye model and a ray tracing algorithm, comparing a predicted refractive outcome to a desired refractive outcome, and based on the comparison, repeating the calculation with an IOL having at least one of a different power, different design, and/or a different IOL location.

The computer system <NUM> may be a general purpose desktop or laptop computer or may comprise hardware specifically configured performing the desired calculations. The computer system <NUM> is configured to be electronically coupled to another device such as a phacoemulsification console or one or more instruments for obtaining measurements of an eye or a plurality of eyes. Alternatively, the computer system <NUM> is a handheld device that may be adapted to be electronically coupled to one of the devices just listed. Alternatively, the computer system <NUM> is, or is part of, refractive planner configured to provide one or more suitable intraocular lenses for implantation based on physical, structural, and/or geometric characteristics of an eye, and based on other characteristics of a patient or patient history, such as the age of a patient, medical history, history of ocular procedures, life preferences, and the like.

The system <NUM> can include or is part of a phacoemulsification system, laser treatment system, optical diagnostic instrument (e. g, autorefractor, aberrometer, and/or corneal topographer, or the like). For example, the computer readable memory <NUM> may additionally contain instructions for controlling the handpiece of a phacoemulsification system or similar surgical system. Additionally or alternatively, the computer readable memory <NUM> may additionally contain instructions for controlling or exchanging data with an autorefractor, aberrometer, tomographer, and/or topographer, or the like.

The system <NUM> can include or is part of a refractive planner. The refractive planner may be a system for determining one or more treatment options for a subject based on such parameters as patient age, family history, vision preferences (e.g., near, intermediate, distant vision), activity type/level, past surgical procedures.

An achromatic optical element or an achromatic surface as described herein can be integrated with other IOLs that improve peripheral vision that are described in <CIT> published as <CIT>. An achromatic optical element or an achromatic surface as described herein can be integrated with the various IOL designs configured to that improve peripheral image quality for patients with AMD that are described in<CIT>, Published as <CIT>); <CIT>, Published as <CIT>); <CIT>, Published as <CIT>); <CIT>) and <CIT>, Published as <CIT>).

The achromatic profile step height can be adjusted to optimize performance for the peripheral region of interest to aid patients with AMD. The step height can be reduced by a factor of cosine of the angle of the preferred retinal locus, to account for the oblique incidence.

The achromatic zone size can be limited to portions of the pupil while leaving some portions of the pupil free of the achromatic optical element to provide clear region to view or inspect the retina. The achromatic optical element can be configured such that the central parts of the achromat contribute to on- axis performance and peripheral parts of the achromat contribute to off-axis performance.

Various lenses and achromats can comprise a material that can block specific parts of the spectrum. For example, the lenses and achromats can comprise a material that can block potentially AMD-inducing blue light. The peak wavelength selected to design various lenses and achromats can be based on the material used to manufacture the lenses and achromats. For example, if the lenses and achromats comprise a material that can block potentially AMD-inducing blue light, the design wavelength can be selected to be greater than <NUM>, in order to optimize the amount of light in the first order focus.

Various concepts, systems and methods described herein can also be used for patients without AMD who wish to improve peripheral vision while gaining superior on-axis vision.

As used herein, the term "processor" refers broadly to any suitable device, logical block, module, circuit, or combination of elements for executing instructions. For example, the processor <NUM> can include any conventional general purpose single- or multichip microprocessor such as a Pentium® processor, a MIPS® processor, a Power PC® processor, AMD® processor, ARM processor, or an ALPHA® processor. In addition, the processor <NUM> can include any conventional special purpose microprocessor such as a digital signal processor. The various illustrative logical blocks, modules, and circuits described herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Processor <NUM> can be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Computer readable memory <NUM> can refer to electronic circuitry that allows information, typically computer or digital data, to be stored and retrieved. Computer readable memory <NUM> can refer to external devices or systems, for example, disk drives or solid state drives. Computer readable memory <NUM> can also refer to fast semiconductor storage (chips), for example, Random Access Memory (RAM) or various forms of Read Only Memory (ROM), which are directly connected to the communication bus or the processor <NUM>. Other types of memory include bubble memory and core memory. Computer readable memory <NUM> can be physical hardware configured to store information in a non-transitory medium.

Methods and processes described herein may be embodied in, and partially or fully automated via, software code modules executed by one or more general and/or special purpose computers. The word "module" can refer to logic embodied in hardware and/or firmware, or to a collection of software instructions, possibly having entry and exit points, written in a programming language, such as, for example, C or C++. A software module may be compiled and linked into an executable program, installed in a dynamically linked library, or may be written in an interpreted programming language such as, for example, BASIC, Perl, or Python. It will be appreciated that software modules may be callable from other modules or from themselves, and/or may be invoked in response to detected events or interrupts. Software instructions may be embedded in firmware, such as an erasable programmable read-only memory (EPROM). It will be further appreciated that hardware modules may comprise connected logic units, such as gates and flip-flops, and/or may comprised programmable units, such as programmable gate arrays, application specific integrated circuits, and/or processors. The modules described herein can be implemented as software modules, but also may be represented in hardware and/or firmware. Moreover, although a module may be separately compiled, a module may alternatively represent a subset of instructions of a separately compiled program, and may not have an interface available to other logical program units.

Claim 1:
An intraocular lens configured to improve vision for a patient's eye, the intraocular lens comprising:
an optic (<NUM>) comprising:
a first surface (<NUM>) having a first curvature; and
a second surface (<NUM>) opposite the first surface (<NUM>), the second surface (<NUM>) having a second curvature greater than the first curvature, the first surface (<NUM>) and the second surface (<NUM>) intersected by an optical axis (<NUM>);
wherein the optic (<NUM>) is configured to focus light incident along a direction parallel to the optical axis at the fovea to produce a functional foveal image,
wherein the optic (<NUM>) is configured to focus light incident on the patient's eye at an oblique angle with respect to the optical axis at a peripheral retinal location disposed at a distance from the fovea, the peripheral retinal location having an eccentricity between <NUM> and <NUM> degrees with respect to the optical axis,
wherein the optic is a meniscus lens with a vertex curving inwards from edges of the optic;
wherein image quality at the peripheral retinal location is improved by reducing at least one optical aberration at the peripheral retinal location;
and characterised by
an achromatic profile disposed on the first surface.