Patent Application
20160346076
The invention is generally directed to the field of treatment of visual deficiency, such as myopia, hyperopia, and astigmatism, either alone, or in combination with myopia or hyperopia. More specifically, the invention is directed to an improved haptic and/or footplate for an posterior chamber phakic intraocular lens (PCPIL).
As shown in
A current PCPIL typically has an optic zone or portion 7 surrounded by a haptic area 12. The PCPIL also has a spherical back radius 10 for both the haptics and optic designed to allow the PCPIL to be applied over the anterior surface of a patient's crystalline lens 30. (
The spherical back radius 10 of the PCPIL also contributes to the optical power of the lens. Implantation of the PCPIL into the eye typically results in a compressive, horizontal force being applied to the footplates and haptics of the lens by the eye. Due to the design of the haptics and footplates, this compressive force has been found to cause the lens to displace axially in an anterior direction. This may be disadvantageous because such an axial displacement may cause, as an example, but not limited to, the anterior surface of the PCPIL pushing the iris of the eye anteriorly to the extent that draining of the aqueous through the angle of the eye could become restricted and the pressure in the anterior chamber of the eye could increase.
As seen in
Moreover, if the PCPIL displaces axially in an uncontrolled manner when implanted, the positioning of the PCPIL within the eye may affect the precision of focus provided by the PCPIL as the effect of the lens is influenced by its proximity to other optical elements within the eye, including the cornea, the crystalline lens and the retina. This may result in a less than optimal visual outcome after implantation.
While an axial displacement that is too great may cause other problems within the eye as well, a PCPIL with too little clearance above the crystalline lens may also be problematic, as such a PCPIL may then contact the crystalline lens.
As is well known, the diameter of the eye available in which to implant a PCPIL can vary from eye to eye. Accordingly, an implanting physician attempts to control the amount of axial displacement of an implanted PCPIL by estimating the size of the eye, and then selects a PCPIL having an appropriate length. In many cases, however, the size of the eye and PCPIL cannot be identically matched, resulting in some residual compressive force on the haptics of the PCPIL, which causes the PCPIL to displace axially.
What has been needed, and heretofore unavailable, is a haptic and footplate design for use with a PCPIL that minimizes or eliminates PCPIL axial displacement as a function of horizontal compression. Further, such a design should improve the ability to properly size and implant the PCPIL such that any axial displacement of the PCPIL after implantation is controlled so as to prevent contact of the PCPIL with either the iris or crystalline lens of the eye. Such an improved PCPIL will also provide for easier and more accurate selection of the appropriate optical power of the PCPIL prior implantation so as to provide more predictable post-operative visual acuity. The present invention satisfies these, and other needs.
In a general aspect, the present invention includes an improved design of the haptics and/or footplates of a PCPIL to minimize or eliminate axial displacement of the PCPIL when the PCPIL is placed under horizontal compression, such as occurs when the PCPIL is implanted in an eye. The improved PCPIL allows the initial axial displacement of the PCPIL to be independent of the overall length of the PCPIL, resulting in the axial displacement of the lens being minimized as the lens is horizontally compressed during implantation. Additionally, the improved PCPIL haptic and footplate design potentially reduces the number of PCPIL lengths that must be kept in inventory to treat a reasonable range of patients. Furthermore, the improvements allow the development of low axial displacement and high axial displacement PCPILs to meet individual patient needs.
In another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; at least two supporting elements, each supporting element mounted to the optic on a diametrically opposed side of the optic; and a footplate disposed at a distal end of each supporting element, the footplate having an angulation that causes the footplate to bend anteriorly when the footplate and support elements are placed under horizontal compression.
In still another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; and at least two supporting elements, each supporting elements having a length and a proximal end mounted to the optic on a diametrically opposed side of the optic, each of the supporting elements also having a footplate disposed at a distal end of the haptic, and each of the supporting elements also having a bending zone disposed along the length of the supporting element and disposed between the proximal and distal ends of the supporting element. In an alternative aspect, the bending zone includes a hinge-like portion. In another alternative aspect, the bending zone includes a compression element. In still another alternative aspect, the bending zone includes a section of the length of the supporting element having a thinner cross-section than the cross-section of the remainder of the length of the supporting element.
In yet another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic, the haptic body having a first side and a second side, the first and second sides located on opposite sides of the optic along a longitudinal axis; a slit or opening disposed within each of the first and second sides of the haptic body; and at least two supporting elements, each supporting elements having a length and a proximal end mounted to the haptic body on a diametrically opposed side of the optic, each of the supporting elements having a distal end having an anterior angulation ranging from greater than 0 degree to 45 degree relative to a planar surface.
In still another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic, the haptic body having a first side and a second side, the first and second sides located on opposite sides of the optic along a longitudinal axis; and at least two supporting elements, each supporting element having a length and a proximal end mounted to the haptic on a diametrically opposed side of the optic, each of the supporting elements configured to deform when compressed so that axial displacement of the optic is minimized due to the compression of lens. In one alternative aspect, the supporting element has an anterior angulation ranging from greater than 0 degrees to 45 degrees. In another alternative aspect, the supporting element tapers from a first thickness at a proximal end to a distal end having a second thickness less than the first thickness. In yet another alternative aspect, the support element tapers from a first thickness at a distal end to a proximal end having a second thickness less than the first thickness. In still another alternative aspect, the supporting element has a distal portion that curves anteriorly. In yet another alternative aspect, the supporting element includes a plurality of grooves disposed on an anterior surface of the supporting element. In still another alternative, the lens includes a slit or opening disposed within each of the first and second sides of the haptic body.
In another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic, the haptic body having a posterior and an anterior side, the posterior side having a non-spherical curvature similar to the curvature of the crystalline lens of an eye; and a first side and a second side, the first and second sides located on opposite sides of the optic along a longitudinal axis; and at least two supporting elements, each supporting elements having a length and a proximal end mounted to the haptic body on a diametrically opposed side of the optic, each of the supporting elements also having at least one tab disposed at a distal end of the supporting element.
In still another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic; at least two supporting elements, each supporting elements having a length and a proximal end mounted to the haptic body on a diametrically opposed side of the optic; and a notch disposed on an anterior side of a junction formed between at least one of the supporting elements and the haptic body.
In yet another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic area; at least two supporting elements, each supporting element mounted to the haptic area on a diametrically opposed side of the haptic area; and a pair of footplates, each footplate having a proximal end joined to one of the two supporting elements, the each footplate having an anterior angulation relative to a planar surface such that the footplate deforms anteriorly when the footplates are placed under horizontal compression. In one alternative aspect, the anterior angulation is selected from the range of greater than 0 degrees and less than 90 degrees. In yet another alternative aspect, the anterior angulation is selected from the range of greater than 0 degrees and less than 45 degrees. In another alternative aspect, the anterior angulation is between 3 and 15 degrees. In still another alternative aspect, the anterior angulation is between 4 and 6 degrees.
In another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic area; and at least two supporting elements, each supporting elements having a length and a proximal end mounted to the haptic area on a diametrically opposed side of the optic, each of the supporting elements also having a distal end, and each of the supporting elements also having a bending zone disposed along the length of the supporting element and disposed between the proximal and distal ends of the supporting element. In another aspect, the bending zone includes a hinge-like portion. In yet another aspect, the bending zone includes a compression element. In still another aspect, the bending zone includes a section of the length of at least one of the supporting elements having a thinner cross-section than the cross-section of the remainder of the length of the supporting element. In still another aspect, the bending zone is disposed along a length of the haptic area. In still another aspect, the at least two supporting elements are anteriorly angled with respect to the haptic area.
In another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic, the haptic body having a first side and a second side, the first and second sides located on opposite sides of the optic along a longitudinal axis; and at least two footplates, each footplate having a length and a proximal end mounted to the haptic body on a diametrically opposed side of the optic, each of the footplates having a portion configured to deform when compressed so that axial displacement of the optic is minimized due to the compression. In one aspect, at least one of the at least two footplates has an anterior angulation ranging from more than 0 degrees to less than 90 degrees. In another aspect, at least one of the at least two footplates has an anterior angulation of greater than 0 degrees and less than 45 degrees. In another alternative aspect, at least one of the at least two footplates has an anterior angulation of between 3 and 15 degrees. In yet another aspect, at least one of the at least two footplates has an anterior angulation of between 4 and 6 degrees. In still another aspect, at least one of the at least two footplates tapers from a first thickness at a proximal end to a distal end having a second thickness less than the first thickness. In still another aspect, at least one of the at least two footplates tapers from a first thickness at a distal end to a proximal end having a second thickness less than the first thickness. In yet another aspect, at least one of the at least two footplates has a distal portion that curves anteriorly. In still another aspect, at least one of the at least two footplates includes a plurality of grooves disposed on an anterior surface of the footplate. In a further aspect, the improved posterior chamber phakic intraocular lens of claim 11, further comprises a slit or opening disposed on an anterior surface of the haptic body. In even another aspect, the haptic body has a first thickness, and the proximal end of at least one of the at least two footplates has a second thickness such that a ratio of the first thickness to the second thickness is between is greater than 1.0 and less than 2.0. In yet another aspect, the haptic body has a first thickness, and the proximal end of at least one of the at least two footplates has a second thickness such that a ratio of the first thickness to the second thickness is greater than 1.25 and less than 1.75. In another aspect, the haptic body has a first thickness, and the proximal end of at least one of the at least two footplates has a second thickness such that a ratio of the first thickness to the second thickness is between is greater than 1.4 and less than 1.6.
In another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic, the haptic body having a posterior and an anterior surface, the posterior surface having a non-spherical curvature similar to the curvature of the crystalline lens of an eye; and at least two supporting elements, each supporting elements having a length and a proximal end mounted to the haptic body on a diametrically opposed side of the optic, each of the supporting elements also having a footplate disposed at a distal end of the haptic body. In another aspect, at least one of the at least two supporting elements has a distal end that is angled anteriorly with respect to the haptic body. In yet another aspect, the distal end of the at least one of the at least two supporting elements has an angulation configured to absorb compressive force applied to the at least two supporting elements so as to reduce anterior axial displacement of the optic resulting from application of the compressive force to the at least two supporting elements.
In still another aspect, the present invention includes an improved posterior chamber phakic intraocular lens, comprising: an optic; a haptic body surrounding the optic; at least two supporting elements, each supporting elements having a length and a proximal end mounted to the optic on a diametrically opposed side of the optic, each of the supporting elements; and a notch disposed on an anterior side of a junction between the haptic body and at least one of the two supporting elements and the haptic.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features of the invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one of ordinary skill in the art, that the present invention may be practiced without these specific details. In other instances, well known components or methods have not been described in detail but rather in a block diagram, or a schematic, in order to avoid unnecessarily obscuring the present invention. Further specific numeric references such as “first driver,” may be made. However, the specific numeric reference should not be interpreted as a literal sequential order but rather interpreted that the “first driver” is different than a “second driver.” Thus, the specific details set forth are merely exemplary. The specific details may be varied from and still be contemplated to be within the spirit and scope of the present invention.
This invention comprises multiple elements of a PCPIL haptic design that will individually and cumulatively minimize or eliminate PCPIL axial displacement as a function of horizontal lens compression.
As can be seen in
Footplates 115 have a proximal end attached to the haptic area 110 and a distal end that is designed to be implanted into the eye. In this embodiment, the footplates are not disposed on a horizontal plane. Rather, the distal ends of the footplates are angled anteriorly at an angle 140 such that the distal end of the footplate is angled towards the anterior side of the PCPIL. The addition of the angulation 140 allows the distal end of the footplates to bend anteriorly when a compression force is imparted to the footplate. This upward angulation thus allows the PCPIL to be compressed when the PCPIL is implanted while eliminating or minimizing the amount of axial displacement of the PCPIL. Those skilled in the art will understand that the amount of angulation of the footplate may be varied depending on the overall design parameters of the PCPIL to ensure that axial displacement of the PCPIL in response to a compressive force on the footplate is minimized or eliminated without departing from the intended scope of the invention. For example, the inventors have observed that the angulation of the footplate relative to a planar surface can range from, for example, greater than 0 degrees to less than 90 degrees; or the angulation may range from greater than 0 degrees to less than or equal to 45 degrees; or the angulation may range between 3 and 15 degrees; or the angulation may range from 4 degrees to 6 degrees; or the angulation may be approximately 5 degrees.
The result of the angulation added to the footplates as discussed above is illustrated in
Note that while notches are shown at being formed at both sides of the PCPIL, the notches could be formed at only one side of the PCPIL. When “sides” is mentioned with respect to the PCPIL, reference is being made to the area of the PCPIL at which the footplates are located.
While several embodiments have been described where the thickness of the haptic area, or one or more portions of the haptic or footplates have been adjusted to control the axial displacement of the PCPIL in the presence of a compression force, those skilled will understand that other arrangements are possible to achieve the same result. The inventors have observed, for example, that reduction in the axial displacement of a PCIPL may be achieved where the ratio of haptic thickness to footplate thickness at the junction of the two is approximately 2.0 to 1.0, and preferably approximately 1.5. For example, for the embodiment of the improved PCPIL illustrated in
In still another embodiment, the posterior radius of curvature of the PCPIL haptic is modified to more closely match the anterior curvature of the human crystalline lens. The anterior surface of the human crystalline lens has more of a flat or elliptical curvature rather than a spherical curvature. Present PCPILs, on the other hand, have a spherical posterior radius. By making at least part of the central part of the PCPIL's posterior curvature to have a flattened or elliptical shape, the PCPIL will have less initial axial displacement. Additionally, this flatter posterior PCPIL design allows for the design of low initial axial displacement or high initial axial displacement PCPILs to accommodate different eye structures.
A flatter posterior PCPIL design contributes to a lower axial displacement of the lens as it is horizontally compressed during implantation. The previously described design elements can, of course, be applied to the flatter posterior curvature PCPIL to optimize the haptic performance and minimize or eliminate axial displacement.
PCPIL 750, which has a flatter aspheric posterior radius of curvature 755 has less initial axial displacement than PCPIL 700, which has a spherical posterior radius of curvature 705. Similarly, PCPIL 800, which has a steeper aspheric posterior radius of curvature 805, has a higher initial axial displacement than PCPIL 700.
Non-spherical or aspheric posterior surfaces of a PCPIL may be generated using a geometrical conic equation and varying the conic constant to achieve posterior shapes that assist in achieving predictable desirable axial displacement of a PCPIL. The equation for a conic section with an apex at the origin and tangent to the Y axis is:
Y
2−2RX+(K+1)X2=0 Equation 1:
where K is the conic constant and R is the radius of curvature at X=0.
This formula is used to specify oblate elliptical (K>0) surfaces, spherical (K=0) surfaces, prolate elliptical (0>K>−1) surfaces, parabolic (K=−1) surfaces, and hyperbolic (K<−1) surfaces. By adjusting the conic constant and aspheric coefficients, an aspheric posterior surface can be optimized to adjust the amount of distance between the anterior surface of the crystalline lens and the posterior surface of a PCPIL.
While various embodiments of the present invention have been described individually, it should be understood that one or more, or all, of the embodiments may be combined to provide a PCPIL design that results in the elimination or minimization of the undesirable axial displacement when the PCPIL is compressed during implantation. The improved PCPIL described above allows the initial axial displacement of the PCPIL to be independent of the overall length of the PCPIL. Moreover, the various embodiments set forth above provide the resulting axial displacement of the lens to be minimized as the lens is horizontally compressed during implantation, and may also reduce the number of lengths of the PCPIL needed to treat a wide range of patients. Further, some embodiments allow the design and manufacture of low axial displacement and high axial displacement PCPILs to meet individual patient needs.
While several particular forms of the invention have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention.
This application claims priority to the earlier filed U.S. Provisional Application No. 62/166,226 filed on May 26, 2015, entitled “Controlled Vault ICL” which is incorporated reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62166226 | May 2015 | US |
