Patent Description:
The human eye includes a cornea and a crystalline lens that are intended to focus light that enters the pupil of the eye onto the retina. However, the eye may exhibit various refractive errors which result in light not being properly focused upon the retina, and which may reduce visual acuity. Many interventions have been developed over the years to correct various ocular aberrations. These include spectacles, contact lenses, corneal refractive surgery, such as laser-assisted in situ keratomileusis (LASIK) or corneal implants, and intraocular lenses (IOLs). In particular, IOLs are also used to treat cataracts by replacing the natural diseased crystalline lens of the eye of a patient. During typical cataract surgery, a conventional single piece IOL is inserted into the capsular bag of a patient to replace the natural crystalline lens.

Whether implanted for refractive errors or for cataract treatment, a typical IOL may shift, either rotationally or axially or in combination, within the capsular bag over time, which may negatively impact the patient's quality of vision. Specifically, the exact location of the lens in the eye may determine the type and degree of refractive power achieved. Therefore, an exact position of the IOL in the eye is assumed when calculating a surgical plan for a patient. When the exact position of the IOL deviates from the surgical plan assumptions, refractive errors may be introduced, which is undesirable.

Also, traditional IOLs may suffer from capsule opacification, which can lead to a loss of transparency and a decrease in the quality of vision. Other problems affected by traditional IOL designs may include, but are not limited, to folds in the capsular bag (striae) and fibrosis around the haptics of the IOL as well as the IOL itself.

Reference is made to the document <CIT> which has been cited as relating to the state of the art. This document discloses a capsule tensioning ring for implantation into the capsular bag of an eye, said capsule tensioning ring is designed to accommodate a fluid, and it has a groove that runs along the circumferential direction in order to thereby hold an intraocular lens in place.

It will be appreciated that the scope is in accordance with the claims.

Accordingly, there is provided an IOL haptic and an IOL that includes the haptic and an optic as defined in claim <NUM>. Further features are provided in the dependent claims. Arrangements outside the scope of the claims may also be described in the specification as background and to assist in understanding the invention. In certain arrangements of the specification, an IOL haptic includes a toroid portion having an outer diameter, an inner diameter, and an interior volume. The interior volume of the toroid portion may be configured to be filled with a fluid. The IOL haptic may further include a receiving feature on the inner diameter of the toroid portion for receiving an IOL optic.

In certain arrangements of the specification, an IOL includes a haptic and an optic. The haptic may include a toroid portion having an outer diameter and an inner diameter and an interior volume configured to be filled with a fluid. The haptic may further include a receiving feature on the inner diameter of the toroid portion for receiving the optic, the optic configured to fit in the receiving feature when the IOL is implanted into an eye of a patient.

In certain arrangements of the specification, a method for implanting an IOL includes inserting a haptic of the IOL into an aphakic eye of a patient, the haptic including a toroid portion having an outer diameter and an inner diameter and an interior volume configured to be filled with a fluid. The haptic further includes a receiving feature on the inner diameter of the toroid portion for receiving an IOL optic. The method further includes filling at least a portion of an interior volume with the fluid, and placing the IOL optic in a receiving feature.

For a more complete understanding of the present invention and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:.

The skilled person in the art will understand that the drawings, described below, are for illustration purposes only. The drawings are not intended to limit the scope of the applicant's disclosure in any way.

The present disclosure relates generally to a fluid-filled haptic for an IOL. The fluid-filled haptic for an IOL disclosed herein may be formed as a fluid-filled toroid that is implanted into the lens capsule and radially exerts pressure against the equator of the capsular bag when filled. The fluid-filled haptic for an IOL disclosed herein may further exert pressure against anterior portions and posterior portions of the capsular bag when filled, in order to aid in anchoring the fluid-filled haptic to the equator of the capsular bag for improved axial and rotational stability. The fluid-filled haptic for an IOL disclosed herein may further maintain a stable and open capsular bag that has been subject to anterior capsulectomy, such as by creation of an anterior capsulorhexis. The fluid-filled haptic for an IOL disclosed herein may also prevent capsular bag opacification, or other negative effects, by keeping the capsular bag open by applying a uniform force around the equator and the posterior capsule. The fluid-filled haptic for an IOL disclosed herein may be implemented as a two piece device comprising a toroid-shaped fluid-filled haptic that receives an IOL optic. The fluid-filled haptic for an IOL disclosed herein may accordingly facilitate postoperative exchange of the IOL optic without affecting the implantation of the fluid-filled haptic.

Referring now to the drawings, <FIG> illustrate an exemplary depiction of a fluid-filled haptic <NUM> for an IOL. <FIG> are schematic diagrams for descriptive purposes and are not drawn to scale or perspective. In <FIG>, a fluid-filled haptic <NUM> is shown including a toroid portion <NUM> and a receiving feature <NUM> for concentrically retaining an IOL optic (not shown in <FIG>) within toroid portion <NUM>. In <FIG>, fluid-filled haptic <NUM> is shown in a filled (or inflated) configuration that corresponds to a post-operative shape within the capsular bag of a patient.

Receiving feature <NUM> is formed to enable retention of the IOL optic by fluid-filled haptic <NUM>. As visible in the sectional view of a fluid-filled haptic <NUM>-<NUM> in <FIG>, receiving feature <NUM> is shown formed as a circular V-groove that extends from a central inner surface of toroid portion <NUM>. Although receiving feature <NUM> is shown as the V-groove extending around an entire inner circumference of toroid portion <NUM> in <FIG> for descriptive purposes, it will be understood that receiving feature <NUM> may be formed using variously shaped structures and elements for retaining the IOL optic, and may be partially formed on the inner circumference, such that receiving feature <NUM> is absent at certain angular locations on the inner circumference of toroid portion <NUM>. For example, in various implementations, receiving feature <NUM> may be any one of : a V-groove, a C-groove, a C-channel, one or more magnetic anchors, among others. In particular implementations, receiving feature <NUM> may be formed with a spring-loaded element (not shown) that secures the IOL optic in the receiving feature <NUM>. For example, the spring-loaded feature may result in an inner diameter of toroid portion <NUM> being smaller than an outer diameter of the IOL optic.

In certain embodiments, fluid-filled haptic <NUM> may be injected by a surgeon into the capsular bag in a deflated or empty configuration, which may be suitable, for example, for injection using an injector with a narrow nozzle that can fit in a relatively small corneal incision. After the deflated fluid-filled haptic <NUM> is inserted into the capsular bag, fluid-filled haptic <NUM> may then be filled with a fluid to form the shape shown in <FIG>. The fluid may be a gas, a liquid, a gel or various combinations thereof, among others. During intraoperative filling of fluid-filled haptic <NUM>, the surgeon may manipulate fluid-filled haptic <NUM> in order to place and position fluid-filled haptic <NUM> in a desired orientation within capsular bag, which may be easier to control and manipulate due to the decreased volume of fluid-filled haptic <NUM> prior to filling. In certain instances, the surgeon may pause and resume the intraoperative filling of fluid-filled haptic <NUM> in order to give the surgeon improved control during the procedure for precise placement of fluid-filled haptic <NUM> within the capsular bag.

In some implementations, fluid-filled haptic <NUM> may have a filling port or a valve to enable filling and draining of the fluid, or components thereof, intraoperatively. For example, receiving feature <NUM> may be formed of a material that is self-sealing when penetrated by a small injector needle, such as a syringe needle or a blunt needle or a cannula, among others, which are generically referred to herein as a "needle". Accordingly, receiving feature <NUM> may be formed with sufficient material at the inner circumference to enable self-sealing. In other implementations, a slit that can be penetrated by a needle may be formed on receiving feature <NUM> to facilitate filling and draining of the fluid. In this manner, receiving feature <NUM> may be reaccessible to the surgeon to add or remove fluid, as desired, for example to titrate fluid into or out of fluid-filled haptic <NUM>. The titration may involve fluid exchange or introduce another fluid or micro particles into toroid portion <NUM> of fluid-filled haptic <NUM>.

As noted, the fluid used to fill toroid portion <NUM> of fluid-filled haptic <NUM> may be a liquid, a gel, or multiple fluids that interact to result in desired properties. For example, in particular implementations where a hardening or curing of the fluid is desired, a curing agent or an ultraviolet (UV) sensitive material may be used. Certain microparticles may be introduced into the fluid for specific purposes, such as but not limited to a UV blocker, refractive index changing micro particles, among other microparticles. In some implementations, the fluid used to fill fluid-filled haptic <NUM> may be provided using separate components that are mixed for a desired effect. For example, the fluid used to fill fluid-filled haptic <NUM> may be provided in two parts, such as a base component and a hardening or curing agent that results in increased stiffness or solidification upon mixing of the two parts, similar to the curing of an epoxy. Even when such a mixture is used for the fluid, fluid-filled haptic <NUM> may retain a certain degree of flexibility, and may remain more flexible during implantation, but after a certain amount of time the fluid may be cured to be more gel-like or to harden or to solidify to a desired degree, which may be controllable by the selection of the constituent components of the fluid and the mixing protocol. When hardening of the fluid within fluid-filled haptic <NUM> is used, the hardening may occur as a result of one or more of: a curing/hardening time, a temperature, moisture, exposure to UV light, exposure to laser light, use of a catalyst, among others.

In other implementations, toroid portion <NUM> of fluid-filled haptic <NUM> may be directly accessed, rather than using receiving portion <NUM> as a port, for example when toroid portion <NUM> is formed using a self-sealing material that enables the surgeon to penetrate through the self-sealing material to fill or drain the fluid or perform the titration techniques mentioned previously.

In various implementations, a material used to form toroid portion <NUM> of fluid-filled haptic <NUM> may be flexible to a certain degree, so as to enable expansion and contraction, depending on an interior pressure of the fluid. Such flexibility may also result in an exterior circumferential diameter of toroid portion <NUM> increasing as the interior pressure of the fluid is increased. Depending on the design and configuration of toroid portion <NUM> and receiving feature <NUM>, the flexibility may result in the interior circumferential diameter of toroid portion <NUM> increasing or decreasing as the interior pressure of the fluid is increased. When the interior circumferential diameter decreases with increasing interior pressure, similar to an inner tube of a tire, the circumferential pressure on the IOL optic may increase, which may stabilize the IOL optic in receiving feature <NUM>.

Additionally, as the exterior circumferential diameter of toroid portion <NUM> increases, fluid-filled haptic <NUM> may fill the capsular bag towards the equator of the capsular bag, which may stabilize fluid-filled haptic <NUM> and the IOL optic by tight fitting within the capsular bag, which is desirable. Furthermore, because fluid-filled haptic <NUM> can be filled in a customized manner for each patient, the expansion of toroid portion <NUM> to adjust to the equator of the capsular bag enables fluid-filled haptic <NUM> to be accurately and snugly fitted to different sized capsular bags that occur in any human population, which improves the clinical applicability of fluid-filled haptic <NUM>. The flexibility and expansion exhibited by fluid-filled haptic <NUM> may allow for a uniform force distribution against the entire equator of the capsular bag when fluid-filled haptic <NUM> is implanted, which is desirable because of the stabilizing effect for fluid-filled haptic <NUM> and the IOL optic. The uniform force distribution may also aid in preventing folds in the capsular bag (striae) due to the resulting tension in the capsular bag, which may evenly prevent folding. The action of fluid-filled haptic <NUM> to keep the capsular bag open by engaging with the capsular bag over the entire external circumference of fluid-filled haptic <NUM> may aid in prevention of posterior capsular opacification (PCO), also referred to as an "after-cataract". In some implementations, fluid-filled haptic <NUM> may have a sharpened or square-edged posterior edge (not shown) that engages with the capsular bag in order to improve PCO prevention.

As a result, the design of fluid-filled haptic <NUM> shown in <FIG> may exhibit improved stability in the capsular bag because fluid-filled haptic <NUM> is anchored to the equator of the bag and may resist being pushed forward by the posterior capsular bag postoperatively, which may provide a high level of axial stability of fluid-filled haptic <NUM> and the IOL optic. In the case of conventional IOLs without fluid-filled haptic <NUM>, the posterior capsular bag may tend to postoperatively collapse onto the conventional IOL. The design of fluid-filled haptic <NUM> shown in <FIG> may also be rotationally stable, because fluid-filled haptic <NUM> is in contact with the equator of the capsular bag over the entire external circumference of fluid-filled haptic <NUM>, which resists undesired post operative rotation.

Fluid-filled haptic <NUM> may also result in a separation between the anterior capsular bag and the posterior capsular bag due to the stability as a result of the uniform force distribution that holds the capsular bag in place. The separation between the anterior capsular bag and the posterior capsular bag, along with the mechanical contact of fluid-filled haptic <NUM> with various portions of the capsular bag, may aid in keeping the capsular bag open and may aid in preventing PCO of the capsular bag, such as a result of, but not limited to: enhanced endocapsular circulation of aqueous humor into the capsular bag, maintenance of a mechanical barrier to prevent cell migration into or out of the capsular bag, mechanical compression of the capsular bag (keeping the capsular bag pushed open), and maintenance of a postoperative contour of the capsular bag.

As shown in <FIG>, fluid-filled haptic <NUM> may be implemented in a so-called "two-piece" implementation, of which one piece is fluid-filled haptic <NUM> while the second piece is the IOL optic (not shown in <FIG>). The two-piece implementation may facilitate a postoperative exchange of the IOL optic, for example, by preventing opacification of the capsular bag by fibrosis around the IOL optic and by providing a stabile setting of the implanted IOL optic. Since toroid portion <NUM> may aid in preventing opacification (or at least fibrosis) of the IOL optic, the IOL optic may be anchored solely using receiving feature <NUM> and may be otherwise freely accessible in the eye. The ease of accessibility of the IOL optic using fluid-filled haptic <NUM> may allow the surgeon to easily grab and manipulate the IOL optic both during the initial implantation and during a subsequent exchange of the IOL optic. Also, because of the decreased interior circumferential diameter of toroid portion <NUM>, as compared with the diameter of the capsular bag, receiving feature <NUM> receives an IOL optic having a smaller diameter than the natural lens at the equator of the capsular bag. The reduced diameter of the IOL optic used with fluid-filled haptic <NUM> may enable the IOL optic to be easier to manipulate intraoperatively and easier to insert and remove from the eye, such as for a subsequent exchange of the IOL optic.

Although the various implementations described above involve filling fluid-filled haptic <NUM> with a liquid or a gel or a hardened fluid intraoperatively, it is noted that the basic structure of fluid-filled haptic <NUM> may be implemented without fluid filling. For example, toroid portion <NUM> may remain hollow (or unfilled) and may be formed using a flexible material that retains a desired shape upon implantation in the capsular bag. possible to have the outside haptic hollow and filled with something other than a liquid. For example, toroid portion <NUM> may be preoperatively formed, or filled, with a desired agent having desired flexibility and mechanical properties. In various implementations, toroid portion <NUM> may be comprised of: a gel, an amorphous solid, an epoxy, a thermoplastic material, a composite material, among others and various combinations thereof.

Also in <FIG>, receiving feature <NUM> may receive various kinds of IOL optics used in ophthalmology. For example, fluid-filled haptic <NUM> may be used with a non-foldable rigid IOL optic, such as comprising a polymethyl methacrylate (PMMA) lens. In some implementations, the IOL optic used with fluid-filled haptic <NUM> may be a flexible IOL optic, in which the optic zone may be comprised of various materials, such as silicone, hydrophobic acrylic, hydrophilic acrylic, hydrogel, collamer or combinations thereof. As shown, fluid-filled haptic <NUM> may also be comprised of various materials, such as polypropylene, PMMA, hydrophobic acrylic, hydrophilic acrylic, silicone or combinations thereof.

During implantation of fluid-filled haptic <NUM> along with the IOL optic into an aphakic eye, various procedures may be performed. First, the natural lens or a previously implanted IOL may be removed to prepare the aphakic eye. Assuming the two-piece implementation, fluid-filled haptic <NUM> may then be injected into the eye and positioned in the capsular bag, while being filled with a fluid, as described above. For example, a fine needle sized between about <NUM> to <NUM> gage may be used to penetrate receiving feature <NUM> in a self-sealing manner when removed after filling the fluid. In some implementations, the needle may have a blunt tip. The fluid may be selected to have a viscosity of at least <NUM> centistokes in particular implementations. Then, the IOL optic may be placed within receiving feature <NUM> after injection into the eye. Once fluid-filled haptic <NUM> and the IOL optic are implanted, a measuring system may be used for guidance and verification of the position of fluid-filled haptic <NUM> and the IOL optic. For example, an ORA ™ System (Alcon Laboratories Inc. Worth, Texas) may be used for spherical, cylinder, and other refractive alignment. In other cases, the measuring system, or optical coherence tomography (OCT) or ultrasound biomicroscopy (UBM) may be used to aid in intraoperative positioning of fluid-filled haptic <NUM> and the IOL optic. It is noted that the fluid may be removed and refilled intraoperatively as desired for snug fitting and placement of fluid-filled haptic <NUM> and the IOL optic.

In addition to the two-piece embodiment shown in <FIG> and described above, a so-called "one-piece" implementation of an IOL having fluid-filled haptic <NUM> and incorporating a fixed IOL optic is also contemplated. The one-piece implementation may provide the advantage of shorter and easier implantation effort, due to having a single injection of the IOL (instead of first injecting fluid-filled haptic <NUM> and then injecting the IOL optic in the two-piece case). Thus, one-piece implementations may reduce surgery time and cost. In the one-piece implementation, the IOL optic, which would be a flexible IOL optic, may be attached using a given number of attachment points (similar to spokes on a wheel) to the interior circumference of toroid portion <NUM>. Then, both toroid portion <NUM> and the attached flexible IOL optic may be folded together and injected in a single step. The attachment points may be configured for removing the IOL optic subsequently in some implementations, such as by cutting through the attachment points. Because the IOL optic is already fixed to toroid portion <NUM> in the one-piece implementation, the operative step of placing the IOL optic in receiving feature <NUM> may be omitted. The one-piece implementation may still be equipped with receiving feature <NUM> to enable implantation of subsequent IOL optics. In another implementation, toroid portion <NUM> and the IOL optic may be tethered together and injected using the same injector, and then assembled intraoperatively.

Referring now to <FIG>, a fluid-filled haptic <NUM> is shown above including toroid portion <NUM> and a receiving feature <NUM> for concentrically retaining an IOL optic (not shown in <FIG>) within toroid portion <NUM>. <FIG> is a schematic diagram for descriptive purposes and is not drawn to scale or perspective. <FIG> is a sectional view with receiving feature <NUM> implemented as a C-groove that is self-sealing when a needle <NUM> penetrates receiving feature <NUM>. Specifically, a needle tip <NUM> is shown penetrating receiving feature <NUM> to enable filling of toroid portion <NUM> with a desired fluid, as described above. The filling of toroid portion <NUM> shown with fluid-filled haptic <NUM> may be performed intraoperatively, as desired to fill or inflate toroid portion <NUM> to a desired fill level or internal pressure.

In <FIG>, a fluid-filled haptic <NUM> is shown depicting how needle tip <NUM> may be used when toroid portion <NUM> is deflated or evacuated. <FIG> is a sectional view with receiving feature <NUM> implemented as a C-groove that is self-sealing when a needle <NUM> penetrates receiving feature <NUM>. For example, fluid-filled haptic <NUM> may be placed in an injector and injected into the eye, as shown in <FIG>. In some implementations, fluid-filled haptic <NUM> may be deflated or evacuated intraoperatively using needle <NUM> to remove the fluid that was previously filled in toroid portion <NUM>.

Although receiving feature <NUM>/<NUM>, as shown in <FIG>, <FIG>, and <FIG>, has been depicted and described as including a recess for receiving and retaining the IOL optic, the present disclosure contemplates that the IOL optic may be received or retained using any suitable receiving or retaining feature that may physically engage and retain the IOL optic in a particular position within toroid portion <NUM>. For example, in other implementations, the receiving or retaining feature of toroid portion <NUM> may include a protrusion (not shown) that mates with a corresponding recess formed in the IOL optic to hold the IOL optic in place. In another example implementation, the receiving or retaining feature may include a spring mechanism that exerts a force against the IOL optic when the IOL optic is placed in position within toroid portion <NUM>, to hold the IOL optic in place. For example, the interior surface of toroid portion <NUM> may include a leaf spring or a leaf clip that is fixed at one end and provides radial compression of the IOL optic at the other end, and remains disposed between the IOL optic and the interior surface of torioid portion <NUM> when the IOL optic is installed to hold the IOL optic in place. It will be understood that various features and retaining mechanisms for the IOL optic may be combined or selected as desired in particular implementations.

In <FIG>, an example of fluid-filled haptic <NUM> placed in an injector casing <NUM> shows how an IOL <NUM> with a fluid-filled haptic may be preloaded into the injector. As shown, IOL <NUM> is loaded into an injector casing <NUM> with a fluid line <NUM> attached, depicting an alternate implementation to the fluid-filling shown in <FIG>. After filling, fluid line <NUM> may be removed intraoperatively.

Referring now to <FIG>, an injection <NUM> of an IOL <NUM> with a fluid-filled haptic is depicted. In <FIG>, IOL <NUM> is shown being injected into a capsular bag <NUM> of an eye of a patient using an injector <NUM>. The injector penetrates the cornea at an incision made for the surgical procedure, which may be as small as <NUM> in length. As shown in injection <NUM>, IOL <NUM> is folded over for injection and may represent the two-piece embodiment with fluid-filled haptic <NUM> shown being injected first, which is followed by the injection of the IOL optic (not shown).

Referring now to <FIG>, an implant <NUM> of IOL <NUM> with a fluid-filled haptic is depicted postoperatively in capsular bag <NUM> of the eye of the patient. In <FIG>, an IOL optic <NUM> is shown placed within a receiving feature <NUM> of IOL <NUM>, depicting how IOL <NUM> is postoperatively immobilized within capsular bag <NUM>.

Referring now to <FIG>, a fluid-filled haptic <NUM> for an IOL is shown in cross-section having a receiving feature <NUM> that is a V-groove. In <FIG>, a first toroid portion <NUM>-<NUM> shows a cross-section with little or no filling of the fluid, while a second toroid portion <NUM>-<NUM> shows how the shape of the cross-section changes with more or increased filling of the fluid. The change in cross-sectional shape of toroid portion <NUM> in <FIG> shows how fluid-filled haptic <NUM> can be fitted into capsular bag <NUM> individually for each patient using fluid filling.

Referring now to <FIG>, a flow chart of selected elements of an embodiment of a method <NUM> for implanting an IOL having a fluid-filled haptic, as disclosed herein. It is noted that certain operations described in method <NUM> may be optional or may be rearranged in different embodiments.

Method <NUM> may begin, at step <NUM>, by inserting a haptic of an IOL into an aphakic eye of a patient, where the haptic further includes a toroid portion having an outer diameter, an inner diameter, and an interior volume configured to be filled with a fluid, and a receiving feature on the inner diameter of the toroid portion for receiving an IOL optic. At step <NUM>, at least a portion of the interior volume is filled with the fluid. At step <NUM>, the IOL optic is placed in the receiving feature. In the method, the receiving feature may be formed as a groove on at least a portion of the inner radius, the groove corresponding in size to a circumferential diameter of the IOL optic and extending circumferentially over at least a portion of the inner diameter, while placing the IOL optic in the receiving feature may further include placing the IOL optic in the groove. In method <NUM>, filling at least a portion of the interior volume with the fluid may further include penetrating the receiving feature using a needle to enable the interior volume to be filled with the fluid using the needle, where the receiving feature is self-sealing to the fluid when the needle is removed. In method <NUM>, inserting the haptic of the IOL into the aphakic eye of the patient may further include folding the toroid portion and the receiving feature in an injector, and using the injector to inject the haptic into the aphakic eye. In method <NUM>, filling at least a portion of the interior volume with the fluid may further include filling the interior volume with the fluid until the outer diameter of the toroid portion circumferentially fits an equator of a capsular bag of the aphakic eye. In method <NUM>, placing the IOL optic in the receiving feature may further include using a measuring instrument to determine a position of the toroid portion in the eye, and selecting the IOL optic based on the position of the toroid portion. Specifically, the measuring instrument may be used to determine or measure an exact position of the receiving feature, since the position of the receiving feature would be determinative for the postoperative position of the IOL optic.

As disclosed herein, an IOL utilizes a haptic formed as a toroid portion configured to fit into a capsular bag of an aphakic eye of a patient. The toroid portion may be separate from an IOL optic and may include a receiving feature for the IOL optic. The toroid portion may be configured for intraoperative fluid-filling for snug fitting at the equator of the capsular bag, in order to immobilize the IOL optic.

Claim 1:
An intraocular lens haptic (<NUM>, <NUM>) comprising:
a toroid portion (<NUM>) having an outer diameter and an inner diameter and an interior volume, wherein the interior volume of the toroid portion is configured to be filled with a fluid; and
a receiving feature (<NUM>, <NUM>) extending from a central inner surface of the toroid portion (<NUM>); and
the receiving feature adapted for concentrically retaining an intraocular lens optic.