Patent Description:
There are about <NUM> million cataract surgeries in United States annually. Bothersome dark spots known as negative dysphotopsia (ND) occur in at least <NUM>% of patients after cataract surgery, and persist in about <NUM>% of patients at <NUM> year. In other words, approximately <NUM>,<NUM> persons in the U. are potentially affected by ND on an annual basis. Currently, there is no way to pre-operatively predict which patients are at risk for ND.

Investigators believe ND is due to light at the intraocular lens (IOL) periphery either refracted or missing the IOL, which distributes light unevenly - resulting in shadows on the retina, which are perceived as dark arcs by the patient.

<CIT> discloses an intraocular lens, comprising a posterior surface that includes a concave peripheral portion.

This document describes intraocular lenses and methods for their use. For example, this document describes intraocular lenses that are shaped with a concave posterior peripheral portion to mitigate occurrences of dysphotopsia.

In one aspect, this disclosure is directed to an intraocular lens that includes an anterior surface bounded by an edge, and a posterior surface bounded by the edge and opposing the anterior surface. The posterior surface includes a concave peripheral portion.

Such an intraocular lens may optionally include one or more of the following features. Portions of the posterior surface other than the concave peripheral portion may be convex. All other portions of the posterior surface other than the concave peripheral portion may be convex. An entirety of the anterior surface may be convex. The intraocular lens may also include two or more haptic members extending from the edge at respective haptic-optic junctions. One of the haptic members may extend from the edge at the concaved peripheral portion. The intraocular lens may also include at least one fiducial marker located on the intraocular lens.

In another aspect, this disclosure is directed to an intraocular lens that includes an anterior surface bounded by an edge and a posterior surface bounded by the edge and opposing the anterior surface. The posterior surface includes a concave portion.

Such an intraocular lens may optionally include one or more of the following features. The concave portion may extend along a portion of the posterior surface adjacent to a junction of the posterior surface and the edge. The edge may extend <NUM> degrees and the concave portion may extend along the portion of the posterior surface from between <NUM> degrees to <NUM> degrees. The concave portion may have a width between <NUM> to <NUM>. All other portions of the posterior surface other than the concave portion may be convex, and an entirety of the anterior surface may be convex. The intraocular lens may also include two or more haptic members extending from the edge at respective haptic-optic junctions. One of the haptic members may extend from the edge at the concaved portion. The intraocular lens may also include at least one fiducial marker located on the intraocular lens.

In another aspect, this disclosure is directed to a method of treating an eye that includes implanting an intraocular lens in the eye. The intraocular lens can include an anterior surface bounded by an edge, and a posterior surface bounded by the edge and opposing the anterior surface. The posterior surface includes a concave portion.

Such a method may optionally include one or more of the following features. The concave portion may be positioned at a nasal orientation relative to the eye. The intraocular lens may also include at least one fiducial marker located on the intraocular lens. The method may also include aligning the at least one fiducial marker at a nasal orientation relative to the eye.

Particular embodiments of the subject matter described in this document can be implemented to realize one or more of the following advantages. In some embodiments, instances of dysphotopsia after cataract surgery can be reduced using the intraocular lens designs described herein. Moreover, both negative and positive dysphotopsia can be potentially prevented or reduced. The intraocular lens designs described herein include posterior surface modifications that can be positioned along only a portion of the intraocular lens (e.g., about <NUM> to <NUM> degrees along the nasal aspect of the intraocular lens), rather than for <NUM> degrees around the entire intraocular lens periphery. As such, limiting the posterior surface treatment to a small portion of the intraocular lens optic may have some optical and manufacturing advantages. In some embodiments, the haptic portion of the intraocular lens is optically used to provide additional enhanced effects to reduce instances of dysphotopsia after cataract surgery.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used, suitable methods and materials are described herein. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein.

Like reference numbers represent corresponding parts throughout.

This document describes intraocular lenses and methods for their use. For example, this document describes intraocular lenses that are shaped with a concave posterior peripheral portion to mitigate occurrences of dysphotopsia. The intraocular lenses described herein are designed to reduce positive and negative dysphotopsias after cataract surgery.

<FIG> is a schematic diagram of a transverse cross-section of an eye <NUM> that includes an iris <NUM>. Iris <NUM> is shown in its preoperative position. Eye <NUM> also includes a native crystalline lens <NUM>.

A conventional prosthetic intraocular lens <NUM> is shown in broken lines. Intraocular lens <NUM> would be implanted after a cataract surgery to remove native crystalline lens <NUM>. The relative size differences and location differences between native crystalline lens <NUM> and its replacement, prosthetic intraocular lens <NUM>, are apparent in <FIG>.

Prosthetic intraocular lens <NUM> is smaller than native crystalline lens <NUM>. For example, in some cases the thickness of prosthetic intraocular lens <NUM> is about <NUM>% of the thickness of the native crystalline lens <NUM>. Also, the diameter of prosthetic intraocular lens <NUM> is smaller than the diameter of native crystalline lens <NUM>. For example, in some cases the diameter of prosthetic intraocular lens <NUM> is between about <NUM>-<NUM>% of the diameter of native crystalline lens <NUM>.

It can also be seen that prosthetic intraocular lens <NUM> is implanted in a more posterior location than native crystalline lens <NUM>. At least, the anterior surface of prosthetic intraocular lens <NUM> is in a more posterior location than the anterior surface of native crystalline lens <NUM>. In result, iris <NUM> will deflect a little more posteriorly than shown in response to the removal of native crystalline lens <NUM>. Even with such a deflection by iris <NUM>, a space or gap will tend to exist between iris <NUM> and prosthetic intraocular lens <NUM>.

Conventional prosthetic intraocular lens <NUM> has a convex anterior surface and a convex posterior surface. An entirety of the optical surfaces (anterior and posterior) of conventional prosthetic intraocular lens <NUM> are convex.

<FIG> is a schematic illustration showing how light rays <NUM> from the temporal field are received by native crystalline lens <NUM>, and are transferred by native crystalline lens <NUM> to a nasal retina <NUM>. One continuous group of light rays <NUM> are received by nasal retina <NUM>. In other words, a single contiguous footprint is made by light rays <NUM> on nasal retina <NUM> after light rays <NUM> pass through native crystalline lens <NUM>.

<FIG> is a schematic illustration showing how light rays <NUM> from the temporal field are received by standard/conventional prosthetic intraocular lens <NUM> and are transferred to nasal retina <NUM>. A portion <NUM> of light rays <NUM> passes between iris <NUM> and conventional prosthetic intraocular lens <NUM>. Light ray portion <NUM> thereby bypasses conventional prosthetic intraocular lens <NUM> and extends to nasal retina <NUM>. Another portion <NUM> of light rays <NUM> passes through conventional prosthetic intraocular lens <NUM> and thereafter extends to nasal retina <NUM>.

Light ray portion <NUM> and light ray portion <NUM> are spaced apart from each other on the nasal retina <NUM>. In other words, the footprint made by light ray portion <NUM> on nasal retina <NUM> and the footprint made by light ray portion <NUM> on nasal retina <NUM> comprise two, separate spaced-apart footprints on nasal retina <NUM>. Said differently, a gap <NUM> exists between the footprint made by light ray portion <NUM> on nasal retina <NUM> and the footprint made by light ray portion <NUM> on nasal retina <NUM>. One of ordinary skill in the art will understand that the existence of gap <NUM> gives rise to the potential for dysphotopsia (e.g., negative dysphotopsia which can symptomatically include one or more arc-shaped shadows usually in the temporal field of vision, or positive dysphotopsia in the form of glare/halos/streaks).

<FIG> provides another representation of the phenomenon described in reference to <FIG>. Here, a chart shows a graph of light intensity received at various locations on the peripheral retina while using a standard intraocular lens. The light intensity in the center region of the circled area is essentially zero, while being bounded on both sides by areas of greater light intensity. The circled location is consistent with the existence of one or more "shadow" region(s) that are symptomatic of negative dysphotopsia.

<FIG> shows another depiction of the retinal illumination in the peripheral retina while using a standard intraocular lens. The first dark area corresponds to a shadow region (e.g., at about <NUM>-<NUM> degrees).

<FIG> shows the intensity display of <FIG> on a polar plot, simulating the visual field shadow in a temporal field seen by patients with negative dysphotopsia.

An example intraocular lens <NUM> in accordance with some embodiments described herein is shown in <FIG> shows a plan view of intraocular lens <NUM>. <FIG> shows a first cross-sectional view of intraocular lens <NUM>, taken along section line <NUM>-<NUM>. <FIG> shows a second cross-sectional view of intraocular lens <NUM>, taken along section line <NUM>-<NUM>.

Intraocular lens <NUM> includes a lens portion <NUM> and first and second haptic members 140a and 140b that extend from lens portion <NUM>. Lens portion <NUM> includes an anterior surface <NUM>, an edge <NUM>, and a posterior surface <NUM>. Anterior surface <NUM> and posterior surface <NUM> oppose each other.

In some embodiments, intraocular lens <NUM> is made of acrylic plastic that is molded, spun-cast, or made by cutting. Haptic members 140a and 140b can be integrally formed with lens portion <NUM>, or separately formed and then attached to lens portion <NUM> (e.g., mounted in drilled holes).

Anterior surface <NUM> is convex. In some embodiments, anterior surface <NUM> is an aspheric convex surface. In some such embodiments, an entirety of anterior surface <NUM> can be an aspheric convex surface.

As depicted by <FIG>, a majority of posterior surface <NUM> is convex. In some embodiments, that majority of posterior surface <NUM> is an aspheric convex surface. However, as depicted by <FIG>, posterior surface <NUM> includes a localized concave peripheral portion <NUM> (that may also be referred to as a "concave portion" or "concave periphery"). That is, while a majority of posterior surface <NUM> is convex, a discrete localized concave peripheral portion <NUM> extending near the edge <NUM> of posterior surface <NUM> is concave. As depicted in <FIG>, the convex area of posterior surface <NUM> meets concave peripheral portion <NUM>. In some embodiments, the convex area of posterior surface <NUM> and concave peripheral portion <NUM> meet by gradually blending into each other from a surface contour standpoint. In some embodiments, the convex area of posterior surface <NUM> and concave peripheral portion <NUM> meet with an abrupt transition (without blending).

In some cases, the width of concave peripheral portion <NUM> is about <NUM> millimeter (mm), or about <NUM>. In some cases, the width of concave peripheral portion <NUM> is in a range of about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, without limitation. Such width ranges of the concave peripheral portion <NUM> are applicable to any of the lens designs described herein. Narrower widths (e.g., <NUM> and less) may advantageously tend to be less likely to contribute to visual artifacts and/or other disruptive optical effects.

In some cases, the concavity of concave peripheral portion <NUM> has a radius of curvature in a range of about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, without limitation. Such radius ranges of the concave peripheral portion <NUM> are applicable to any of the lens designs described herein.

Concave peripheral portion <NUM> extends along just a portion of edge <NUM>. In some cases, concave peripheral portion <NUM> extends for about <NUM> degrees of the <NUM> degrees of edge <NUM>. In some cases, concave peripheral portion <NUM> extends for about <NUM> degrees of the <NUM> degrees of edge <NUM>. In some cases, concave peripheral portion <NUM> extends in a range of about <NUM> degrees to about <NUM> degrees, or about <NUM> degrees to about <NUM> degrees, or about <NUM> degrees to about <NUM> degrees, or about <NUM> degrees to about <NUM> degrees, or about <NUM> degrees to about <NUM> degrees, or about <NUM> degrees to about <NUM> degrees, or about <NUM> degrees to about <NUM> degrees. In some cases, concave peripheral portion <NUM> extends for all <NUM> degrees of the <NUM> degrees of edge <NUM>. Such ranges of radial extension of the concave peripheral portion <NUM> are applicable to any of the lens designs described herein. Concave peripheral portions that are arcuate segments (e.g., extending less than <NUM> degrees) may be advantageous to preserve aspheric treatments to lens periphery to help users see with better contrast sensitivity. Embodiments with two segments (<NUM> degrees from each other) would allow the surgeon to orient either of the modified portions nasally. Even with two modified segments, about one half of the optic edge periphery would be maintained as originally designed, to lessen the chance of affecting foveal vision or inducing unwanted artifacts.

Limiting the concave peripheral portion <NUM> to a portion of the <NUM> degrees of edge <NUM> may facilitate some optical and manufacturing advantages. By limiting the concave peripheral portion <NUM> to a portion of the <NUM> degrees of edge <NUM>, any other portion of the IOL that does not contribute to ND reduction can be maintained as the convex posterior surface for the best imaging with regular foveal vision. The extent of the concavity of concave peripheral portion <NUM> is selectable.

The depth of concave peripheral portion <NUM> is exaggerated in <FIG> so that the general shape of concave peripheral portion <NUM> can be clearly envisioned. The intersection of concave peripheral portion <NUM> and edge <NUM> is a sharp edge (and more sharp and pointed than the intersection of posterior surface <NUM> and edge <NUM> at regions other than concave peripheral portion <NUM>). The edge <NUM> may be frosted or not frosted.

In the depicted embodiment, edge <NUM> is parallel to the central axis of intraocular lens <NUM> (the central axis being orthogonal to the paper in the context of <FIG>, and being within the plane of the paper in the context of <FIG>). Accordingly, edge <NUM> is essentially cylindrical (not frustoconical).

As described further below, concave peripheral portion <NUM> alters the peripheral optic surface curvature of intraocular lens <NUM> to maintain all available light on the light-sensitive retina but redirects it in such a way that it falls more uniformly on the retina, avoiding creating bright areas (positive dysphotopsia) and shadows (negative dysphotopsia).

<FIG> is a schematic illustration showing how light rays <NUM> from the temporal field are received and transmitted by example intraocular lens <NUM>. It is noteworthy that the shape of concave peripheral portion <NUM> causes part of light ray portion <NUM> to be fanned outward to a greater extent as compared to a convex-shaped posterior surface (e.g., as with a conventional intraocular lens such as the conventional intraocular lens <NUM> shown in <FIG>). Consequently, the footprint on nasal retina <NUM> of light ray portion <NUM> is enlarged, thereby reducing or eliminating gap <NUM> (shown in <FIG>).

Ray trace analysis shows that rays entering a pseudophakic eye from light sources between <NUM>-<NUM> degrees of visual angle can be refracted to different positions on the peripheral retina through specific intraocular lens design modifications such as having a concave peripheral posterior surface portion. The new positioning of the theoretical ray paths provides more uniform illumination of the peripheral retina. Analysis indicates that specific intraocular lens optic design modifications that alter how light entering the eye at large visual angles is diverged and redirected onto the peripheral retina may result in reduced rates of dysphotopsia after cataract surgery.

The modified intraocular lens design (to include the peripheral posterior concave portion) can be made less dependent on the IOL diopter power if the Anterior Chamber Depth, A-constant, or other Lens Constants are taken into account during the design process. Also, Astigmatism-correcting Toric IOLs can be made to include the peripheral posterior concave portion as described herein. In some cases, a right eye and a left eye specific design is used. Alternatively, in some cases a universal design is used (not right eye and left eye specific).

<FIG> are schematic illustrations showing how light rays from the temporal field at <NUM> degrees and <NUM> degrees, respectively, are received by conventional prosthetic intraocular lens <NUM> and are transmitted to the nasal retina <NUM> as light ray portion <NUM>. It can also be seen how some of the light rays from the temporal field at <NUM> degrees and <NUM> degrees bypass intraocular lens <NUM> and extend to the nasal retina <NUM> as light ray portion <NUM>. (The rays bypassing the IOL are incident at <NUM> degrees in both figures, and in the next two similar figures. ) Gap space <NUM> on nasal retina <NUM> between the footprints of light ray portions <NUM> and <NUM> is created. Accordingly, shadows (negative dysphotopsia) corresponding to gap space <NUM>, and bright areas (positive dysphotopsia), may result with the use conventional prosthetic intraocular lens <NUM>.

<FIG> are schematic illustrations showing how light rays from the temporal field at <NUM> degrees and <NUM> degrees, respectively, are received and transmitted to the nasal retina <NUM> by intraocular lens <NUM> having a concave posterior peripheral portion <NUM> (e.g., refer to <FIG>). It can be seen how some of the light rays from the temporal field at <NUM> degrees bypass intraocular lens <NUM> and extend to the nasal retina as light ray portion <NUM>. However, light ray portion <NUM> (which passes through intraocular lens <NUM>) is shaped by concave posterior peripheral portion <NUM> such that at least a part of the light ray portion <NUM> is transmitted to nasal retina <NUM> while being spread to create a broader footprint on nasal retina <NUM> in comparison to conventional intraocular lens <NUM> (<FIG>). Consequently, the gap space on nasal retina <NUM> between the footprints of the light rays <NUM> and <NUM> transmitted by intraocular lens <NUM> is reduced as compared to conventional lens <NUM> of <FIG>.

<FIG> show a comparison of peripheral retina illumination while using a standard/conventional IOL (<FIG>) and a "modified" IOL with a concave posterior peripheral portion (<FIG>) as described herein. <FIG> shows a shadowed region, absent illumination. The same area of <FIG> has intensities that are greater than zero, indicating illumination and the elimination of shadowed regions. (The sharp oscillations of the intensity are artifacts of the simulation conditions, not actual individual intensity spikes.

<FIG> again illustrates intraocular lens <NUM>. In this embodiment, optional fiducial markers 150a and 150b are included. Fiducial markers 150a and 150b can be used by a surgeon during the surgery to visually orient intraocular lens <NUM> relative to the eye in a desired nasal location or orientation. In this embodiment, posterior peripheral concave peripheral portion <NUM> is bisected by the nasal position, and by fiducial marker 150b. That is, half of concave peripheral portion <NUM> is above the nasal position (and fiducial marker 150b) and the other half of concave peripheral portion <NUM> is below the nasal position (and fiducial marker 150b). While in the depicted embodiment, two haptic members 140a and 140b are included, in some embodiments four haptic members (for four-point fixation) are included.

<FIG> illustrates another example intraocular lens <NUM>. In this example, a posterior peripheral concave portion <NUM> is located at the junction between a lens <NUM> and a haptic member 240b. In other words, concave portion <NUM> is located at the haptic-optic junction. In some cases, concave portion <NUM> is centered with respect to the haptic-optic junction, but such an orientation is not required in all embodiments. In some embodiments, the concave surface profile of concave portion <NUM> can extend into a portion of haptic member 240b (even beyond what is illustrated in <FIG>). In some embodiments, the concave surface profile of concave portion <NUM> abruptly ends at the arcuate junction between the round lens <NUM> and haptic member 240b (the haptic-optic junction), as depicted. The surface of the portion of haptic member 240b near the haptic-optic junction can be flat or contoured in any manner desired. In some embodiments, the haptic-optic junction can thereby be exploited to maximize uniform illumination of the peripheral retina by refracted light, to provide additional enhanced effects to reduce instances of dysphotopsia after cataract surgery.

Still referring to <FIG>, the portion of posterior surface modification is in proximity to a haptic member 240b and/or 240a on the nasal side and/or temporal side. In one example, a lens (e.g., <NUM> index material) was modeled with a cone of haptic material outside the <NUM> diameter optic (of <NUM> optic edge thickness) that goes to <NUM> diameter (of <NUM> haptic thickness) representing the optic-haptic junction, and is then flat (at <NUM> haptic thickness) out to the haptic tip.

Referring to <FIG>, if the standard biconvex intraocular lens like <FIG> is used, another light intensity display plot illustrates that in some cases light can bypass the <NUM> optic at IOL edge and create the illuminated area (labeled "Light missing IOL") representing ND, that is the dark band (absent light) between this bypassing light and the main white band on the left of the plot of <FIG>.

Referring to <FIG>, if the example intraocular lens <NUM> of <FIG> is used, the light that bypassed the IOL edge of the <NUM> optic (as depicted in <FIG>) instead hits the extended surface(s) of the optic-haptic junction and is refracted into a different direction, or is internally reflected, eliminating most of the second band of light (that was labeled "Light missing IOL" in <FIG>) that creates the ND.

In selected configurations, there is an additive effect to reduce ND further when the posterior surface modification described in this disclosure is located at an optic-haptic junction oriented to the horizontal meridian. <FIG> illustrate this reduction of the dark band extent, in two light intensity display plots of additional intraocular lens configurations that have a posterior concave peripheral portion located at or along the junction between the lens and a haptic-optic junction (e.g., as depicted in <FIG>). In each of these cases, the concave annulus has a radius of curvature of <NUM> and is <NUM> wide, but is surrounding a central posterior optic of a different diameter. In <FIG>, the modification extends only to the <NUM> optic diameter, but in <FIG> the modification extends slightly into the optic-haptic junction itself at a diameter of <NUM> (but not the full <NUM> described in reference to <FIG>). Based on these plots, and the bands from about <NUM> to <NUM> degrees which are gray instead of the previous black, it can be envisioned that ND can be mitigated or prevented using such an intraocular lens design. Some light that might otherwise bypass the IOL edge beneficially passes through the haptic or optic-haptic junction, and other light is redirected by the modified concave posterior periphery.

<FIG> illustrates another example intraocular lens <NUM>. In this example, a posterior peripheral concave portion <NUM> is biased at a slightly inferior position. In other words, a greater percentage of the length of concave portion <NUM> is inferior of the nasal position as compared to superior to the nasal position.

<FIG> illustrates another example intraocular lens <NUM>. This example also has a posterior peripheral concave portion <NUM> that is biased to a slightly inferior position. Here this is based on the surgical placement of the haptic members 440a and 440b extending superiorly and inferiorly from the edge of intraocular lens <NUM>.

As illustrated by <FIG>, all the embodiments described herein can have their haptic members (e.g., haptic members 140a-b, 240a-b, 340a-b, and 440a-b) and their peripheral concave portions (e.g., peripheral concave portions <NUM>, <NUM>, <NUM>, and <NUM>) oriented in any desired location relative to the nasal and temporal positions. Any and all combinations and permutations of such features, and all other features described herein, are within the scope of this disclosure.

Moreover, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Moreover, the separation of various system modules and components in the embodiments described herein should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single product or packaged into multiple products.

Claim 1:
An intraocular lens (<NUM>), comprising:
an anterior surface (<NUM>) bounded by an edge (<NUM>); and
a posterior surface (<NUM>) bounded by the edge (<NUM>) and opposing the anterior surface (<NUM>),
wherein the posterior surface (<NUM>) includes a concave peripheral portion (<NUM>),
wherein the concave peripheral portion (<NUM>) is an arcuate segment extending around the intraocular lens periphery in a range of <NUM> degrees to <NUM> degrees of the <NUM> degrees of the edge (<NUM>), and
wherein portions of the posterior surface (<NUM>) other than the concave peripheral portion (<NUM>) are convex.