Patent Description:
Traditionally, contact lenses were developed and marketed to be used on the external surface of the eye. Contact lenses were first manufactured using glass, although this was later substituted with biocompatible materials that minimize any reaction of the eye. Subsequently, the aphakic intraocular lens ("IOL") was invented to replace the natural lens due to eye problems such as cataracts. Further development led to the posterior chamber phakic intraocular lens ("PCP-IOL"), which was particularly useful in younger patients having a functional natural lens.

Even after decades of development, however, PCP-IOLs suffer from a number of persistent drawbacks and shortcomings. In some instances, those drawbacks lead to serious complications for patients.

One drawback relates to the sizing of a PCP-IOL for a patient's specific anatomy. The challenge in sizing PCP-IOLs is that the ciliary sulcus, where the PCP-IOL is to be positioned, is significantly different from person to person. In fact, the size of the ciliary sulcus typically ranges between <NUM> and <NUM>. If a physician implants an undersized PCP-IOL for the patient's anatomy (<FIG>), the PCP-IOL may inadvertently contact the surface of the natural lens, thus affecting the precision of the lens system and possibly causing cataract formation. In addition, in cases involving PCP-IOLs for correcting astigmatism, an undersized lens can result in loss of corrective power of the PCP-IOL.

On the other hand, if a physician implants an oversized PCP-IOL for the patient's anatomy (<FIG>), the PCP-IOL may result in complications as severe as glaucoma by pupillary blockage. In some cases, an oversized PCP-IOL leads to other complications. For example, implanting an oversized PCP-IOL can lead to pressure decompensation between the anterior and posterior chambers of the eye due to the pupillary blockage of the aqueous humor by the anterior part of the PCP-IOL, on the trabeculum. To avoid such blockage, physicians often perform an iridectomy in connection with a PCP-IOL implantation. An iridectomy is a surgical puncture of the iris that establishes a passageway for the proper flow of aqueous between the anterior chamber and the posterior chamber. However, to resolve the blockage problem without creating other complications, the iridectomy requires a highly skilled and experienced physician. Iridectomies are often times painful, or at least appreciably uncomfortable, for the patient.

As an alternative to an iridectomy, certain PCP-IOLs have been created with a central hole in the lens that allows flow of aqueous between the anterior and posterior chambers, considerably improving the pressure compensation or equalization between the chambers. But such a hole in the lens seriously degrades lens quality because it causes light scattering and dazzling. This, in turn, results in positive and/or negative dysphotopsia.

Yet another drawback with certain prior art PCP-IOLs is that they have an anterior surface or other parts that rasp or restrict movement of the iris during dilation of the pupil, thus causing depigmentation. Document <CIT> discloses an intraocular lens with channels traversing through the surface of the lens optic for allowing flow of aqueous humor and then reducing the occurrence of pseudophakic pupillary block. Document <CIT> discloses an intraocular lens for implantation in an eye following cataract extraction, comprising flexible compressive loops attached to a lens, and a support structure at its rear face of the lens. Document <CIT> discloses a phakic intraocular lens comprising arms for holding the lens in proper position and orientation in an eye. Document <CIT> discloses an intraocular lens whose a front surface comprises support projections forming channels between the front surface and an eye's iris. Document <CIT> discloses a phakic intraocular lens comprising an annular surface protruding from an anterior surface of the lens or surrounding the lens for making contact with an eye's iris. Document <CIT> discloses a lens implant for use as a replacement for a cataractic lens, the lens implant having a side with at least two arcuate ridges for an implantation in an eye with less irritation and less risk of infection. Document <CIT> discloses a lens device comprising an optical part, two generally flat haptic structures at radially opposite sides of the optical part, a vaulted section connecting the optical part and the haptic structures, and at least one opening for allowing liquid flow through the device. A defect of the above-mentioned intraocular lens is that they do not allow for a stable natural positioning of the lens in an eye's posterior chamber at a sufficient vaulted distance of a natural crystalline of this eye, while ensuring a permanent aqueous flow through the lens. Document <CIT> falls under Article <NUM>(<NUM>) EPC.

The invention is defined in claim <NUM>, while embodiments of the invention are defined in the dependent claims.

The following presents a simplified summary of the disclosure in order to provide a basic understanding of some aspects of the disclosure. This summary is not an extensive overview of the disclosure. It is intended neither to identify key or critical elements of the disclosure nor to delineate the scope of the embodiments disclosed herein; its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

One or more of the preceding drawbacks of currently available PCP-IOLs are improved and an advance is made in the art by a novel PCP-IOL. According to one aspect of the disclosed embodiments, a PCP-IOL includes a haptic, adjustable struts, a collar, a lens, and a passageway that communicates between the front and back of the PCP-IOL.

In accordance with one example a PCP-IOL generally comprises: a smooth and continuous collar over a haptic, the collar having a steep inclination with smooth edges towards a lens zone. In use, the collar creates a "tent" or pocket between the posterior face of the iris and the anterior surface of the PCP-IOL, allowing for natural positioning. The presence of one or more peripheral orifices, slits, passageways, or holes that connect an anterior surface and a posterior surface of the PCP-IOL may facilitate the passage of the aqueous humor. The positioning of such an orifice may eliminate or reduce dysphotopsic effects as set forth below. In some embodiments, both the haptic and the lens zones form a substantially continuous surface, adjusting smoothly to the anterior surface of the crystalline lens.

As disclosed herein, a haptic region includes two zones: proximal wings and distal adjustable struts that are partially separated from the wings. The shape and flexibility of the adjustable struts may allow for compression radially towards the lens, enhancing adaptation of PCP-IOL <NUM> to the ciliary sulcus.

The following description and the appended drawings set forth certain illustrative aspects of the implementations presented in the disclosure. These aspects are indicative, however, of but a few of the various ways in which the principles of the disclosure may be employed.

Other advantages and novel features will become apparent from the following description when considered in conjunction with the drawings.

The following detailed description and the appended drawings describe and illustrate some implementations for the purpose of enabling one of ordinary skill in the relevant art to make and use these implementations. As such, the detailed description and drawings are purely illustrative in nature and are in no way intended to limit the scope of the disclosure in any manner. It should also be understood that the drawings are not necessarily to scale and in certain instances details, which are not necessary for an understanding of the disclosure, may have been omitted, such as details of fabrication and assembly.

In general, <FIG> and <FIG> illustrate a posterior chamber phakic intraocular lens ("PCP-IOL") <NUM> that adapts to an eye's anatomy to facilitate correction and treatment of ametropia and presbyopia, for example, or to ameliorate or minimize the effects of other eye disorders or vision deficiencies. In some embodiments, PCP-IOL <NUM> has a haptic <NUM>, a central lens <NUM> and an orifice <NUM> between an anterior surface and a posterior surface of PCP-IOL <NUM>. As illustrated in <FIG>, haptic <NUM> comprises an elevated collar <NUM>, wings <NUM>, radially-elastic, adaptable struts 27a-d, and a central lens <NUM>. A peripheral orifice <NUM> (defining an opening or passage between an anterior surface and a posterior surface of PCP-IOL <NUM>) may be positioned proximate collar <NUM> and may be generally operative to allow aqueous flow either through lens <NUM> (e.g., <FIG>, and <FIG>) or collar <NUM> itself (e.g., <FIG>, <FIG>, <FIG>). Lens <NUM> may be secured to the structure of haptic <NUM> in any of various ways generally known in the art; in that regard, the term "secured" in this context is intended to refer to any suitable technology or method operative to secure, fixedly attach, integrate, or otherwise to fuse or join lens <NUM> with haptic <NUM> consistent with their interoperability as are known in the art or developed in accordance with known principles.

Referring to <FIG>, orifice <NUM> may permit aqueous flow (depicted by arrows <NUM>) between the anterior and posterior chambers of the eye, while collar <NUM> protects the opening of orifice <NUM> by deflecting iris <NUM> away from orifice <NUM>. This deflection may serve to prevent iris <NUM> from occluding, obstructing, sealing or otherwise adhering to orifice <NUM> in a way that dangerously limits aqueous flow between the anterior and posterior chambers when the pupil is constricted. Struts <NUM> facilitate sizing of PCP-IOL <NUM> to the size of a patient's ciliary sulcus. Struts <NUM> may also function dynamically to position PCP-IOL <NUM>, and in particular, to center lens <NUM>, relative to a patient's natural lens.

<FIG> illustrates one embodiment of haptic <NUM>, which forms a platform for PCP-IOL <NUM>. Haptic <NUM> is formed from any suitable flexible, biocompatible material (which has appropriate or desired optical qualities or lensing characteristics) that will be known to those of skill in the pertinent art. The surface of haptic <NUM> (and in particular, the surface of collar <NUM> that is in contact with iris <NUM>) is preferably substantially smooth and curvilinear in order to preserve the pigmentation by avoiding a rough rubbing of iris <NUM> by haptic <NUM>, in general, and collar <NUM>, in particular. The shape and flexibility of PCP-IOL <NUM> allows it to be folded and unfolded by a physician to permit implantation in an eye.

Haptic <NUM> includes lateral wings <NUM> and elastic struts 27a-d spaced apart from wings <NUM>. Struts 27a-d of haptic <NUM> may be provided in different sizes, some being relatively shorter (<FIG>) or relatively longer (<FIG>) than others. Additionally or alternatively, struts 27a-d may be diverging (<FIG>) or converging (<FIG>). The radial elasticity of struts 27a-d permits flexing of the struts 27a-d in a way that reduces the exterior size of PCP-IOL <NUM>, as shown in <FIG>. As shown in <FIG>, the radial elasticity of struts 27a-d results in a range of motion (represented by the angle indicated at reference numeral <NUM>). Struts 27a-d therefore provide significant tolerance or adaptability in use. In some embodiments, struts 27a-d allow adjustment between about <NUM> microns and about <NUM> microns. Such tolerance facilitates achieving a preferred <NUM>-<NUM> space or gap (known as "vaulting") between lens <NUM> and an eye's natural lens even when there are differences between the predicted and actual size of the ciliary sulcus <NUM>. Struts 27a-d also act to center and position lens <NUM> relative to the natural lens. Struts <NUM> can be provided at an angle between <NUM> degrees and <NUM> degrees relative to haptic <NUM>. It is noted that the particular size, shape, orientation, and range of motion <NUM> of struts 27a-d may vary in accordance with eye anatomy, material selection, governmental or health code regulations, or a combination of these and other factors. The present disclosure is not intended to be limited by any particular configuration of struts 27a-d.

As best illustrated in <FIG>, haptic <NUM> may further include an elevated collar <NUM> forming a curved wall. The ends and surface of collar <NUM> may be smoothly sloped, curved, or graded into the structure of haptic <NUM>, as illustrated in the embodiments of <FIG>, <FIG>, and <FIG>. Such sloping allows collar <NUM> gently to bias or direct iris <NUM> away from orifice <NUM> without causing depigmentation. For example, as illustrated in <FIG>, when the pupil is constricted, collar <NUM> protects orifice <NUM> from penetration by iris <NUM>. That is, as the posterior surface of iris <NUM> slides over collar <NUM>, the elevation of collar <NUM> (as compared to other portions of haptic <NUM>) creates a natural chamber or tented region, allowing iris <NUM> to extend past orifice <NUM> without clogging, obstructing, occluding, or otherwise interfering with same. Because iris <NUM> passes over, but does not penetrate or directly obstruct orifice <NUM>, it does not create a seal over orifice <NUM> or adhere to it. In some implementations, collar <NUM> also protects orifice <NUM> from obstruction when the pupil is dilated as shown in <FIG>. This allows flow of aqueous at all times.

Collar <NUM> may be a circumferential collar, or ring, that extends around all or substantially all of the circumference of lens <NUM> as shown in <FIG>, for example. In alternative embodiments, collar <NUM> may be implemented as a partial collar that extends around some portion of lens <NUM>. <FIG>, for example, illustrates an embodiment having an asymmetrical partial collar <NUM> in a superior portion of PCP-IOL <NUM>. As yet another alternative, collar <NUM> may be formed as an elevation or bulge, as shown in <FIG>. In still other embodiments, collar <NUM> may be positioned laterally beside lens <NUM>.

Orifice <NUM> may be provided through lens <NUM> as a slit, hole, or other suitable passageway; it is noted that it may be desirable in some embodiments to implement orifice <NUM> as a series or plurality of holes, slits, passageways, or perforations. By way of example, <FIG>, <FIG>, and <FIG> illustrate orifice <NUM> as a slit or crescent or U-shaped opening through lens <NUM>. Alternatively, orifice <NUM> may be provided through haptic <NUM>, and more specifically, through a wall at the intersection of haptic <NUM> and lens <NUM> (see <FIG>). For example, <FIG>, <FIG>, and <FIG> show orifice <NUM> as a passageway through haptic <NUM>. As noted above, multiple orifices may be provided in lens <NUM>; alternatively, an orifice <NUM> (or more than one) may be provided in both lens <NUM> and haptic <NUM>. Various configurations are contemplated, and the present disclosure is not intended to be limited to any particular location or configuration of a single instance or multiple instances of orifice <NUM>.

Referring to <FIG>, a superior location of orifice <NUM> may limit usual dysphotopsic effects because orifice <NUM> is concealed under the eyelid's shadow cone. That is, certain strategic positioning of orifice <NUM> may limit unwanted light scattering or dazzling effects in some instances because light rays <NUM> entering the eye are substantially or entirely blocked by the natural position of the open eyelid <NUM>. Further, when the pupil is constricted, iris <NUM> may fully block light from entering orifice <NUM>.

<FIG> shows that the elevation (or "height") <NUM> of a ridge associated with collar <NUM>, in order to create a tent above an anterior surface <NUM> of lens <NUM> proximal to orifice <NUM>, is such that it can create a greater unevenness <NUM> between a transition zone <NUM> and lens <NUM>, depending on the dioptric power and shape of the lens <NUM>. The unevenness <NUM> may be provided with smooth or rounded sides in order to achieve a soft rubbing with low friction against iris <NUM>. In the foregoing manner, it is possible to enable aqueous humor to flow through orifice <NUM> in the tented region.

Some embodiments may be adapted for use with a lens having a positive (+) meniscus. As shown in <FIG>, for a convex lens <NUM>, a periphery of lens <NUM> is positioned in a posterior plane <NUM>. That is, lens <NUM> is "sunken" or recessed in haptic <NUM>. This is because the pupil contracts and iris <NUM> gets closer to the highest elevation area of lens <NUM>. This elevation area is preferably at the same or at a lower level of collar <NUM> to produce the tenting effect discussed above. As noted above, PCP-IOL <NUM> is generally manufactured of biocompatible materials and comprises a lens component (lens <NUM>), a two-zone haptic component (comprising haptic <NUM> and collar <NUM>), and a transitional area between these two parts (such as represented by reference numerals <NUM> and <NUM> in <FIG>).

Alternative embodiments may be adapted for use in connection with lenses having a negative (-) biconcave surface. As shown in <FIG>, where there is a thinning in the central area of lens <NUM> (i.e., the lens is positioned lower with respect to its boundary) the periphery of lens <NUM> may be located in a continuous mode regarding the anterior part of haptic <NUM>.

Claim 1:
A posterior chamber phakic intraocular lens (<NUM>) having an anterior surface and a posterior surface, and comprising:
a haptic (<NUM>); a lens (<NUM>) secured to the haptic (<NUM>); and
a passageway (<NUM>) extending between the anterior surface and the posterior surface; wherein aqueous flow is permitted through the passageway (<NUM>)
wherein the haptic (<NUM>) comprises :
- proximal wings (<NUM>);
- distal struts (27a-d) that are partially separated from the proximal wings (<NUM>) and that are radially elastic; and
characterised in that the haptic (<NUM>) further comprises:
- an elevated collar (<NUM>) extending around at least a portion of the lens (<NUM>) and extending anteriorly with respect to the lens (<NUM>), the elevated collar
having a steep inclination with smooth edges towards the lens (<NUM>);
and in that the passageway (<NUM>) is positioned beside the elevated collar (<NUM>).