Abstract:
An intraocular lens implant includes a lens having an anterior portion, a posterior portion, and a circumferential edge located therebetween. An annular notch is formed in the anterior portion and oriented in an anteriorly-directed orientation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a divisional of co-pending U.S. patent application Ser. No. 13/083,853, filed on Apr. 11, 2011, which claims the filing benefit of U.S. Provisional Patent Application Ser. No. 61/323,060, filed on Apr. 12, 2010, the disclosures of which are hereby incorporated herein by reference in their entireties. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This present invention relates generally to intraocular lens implants and, more particularly, to intraocular lens implants and surgical methods for reducing negative dysphotopsia. 
       BACKGROUND OF THE INVENTION 
       [0003]    The human eye is the sensory organ for reacting to light. As shown in  FIG. 1 , the anatomical structure of an anterior segment of the eye  10  is shown and includes a transparent outer layer, the cornea  12 , that is continuous with an opaque sclera  14  forming the lateral white portion of the eye  10 . The cornea  12  encloses an anterior chamber  16  and posterior chamber  18 , both filled with aqueous humor. The anterior and posterior chambers  16 ,  18  are separated by the iris  20 , which is a circular, muscular structure that controls the diameter of the centrally-disposed pupil  22  and provides the color portion of the eye  10 . 
         [0004]    Light enters the eye  10  through the cornea  12 , passes through the aqueous humor of the anterior chamber  16  and the pupil  22  to the lens  24 . The lens  24  is a transparent, biconvex structure that focuses incoming light onto the retina (not shown). Suspensory ligaments, or zonules  26 , suspend the lens  24  from ciliary bodies  28 , which are muscular structures that contract to affect the convexity, i.e., shape, of the lens  24  and thereby adjust the focal distance of the eye  10 . The lens  24  itself is comprised of an outer membrane, the capsular bag  30 , surrounding a group of compressed cells, the nucleus  32 , and a less dense compression of cells, the cortex  34 . 
         [0005]    Cataracts are a medical condition that is manifested as decreased transparency, or clouding, of the lens  24  within the eye  10 . The clouding may occur to any portion of the lens  24 , including the nucleus  32 , the cortex  34  and/or the capsulor bag  30 . Cataracts generally develop bilaterally, i.e., affecting both eyes, and to varying degrees ranging from a slight clouding to complete opacity and greatly reduce the transmission of light through the lens  24  to the retina (not shown). If left untreated, cataracts may result in blindness. 
         [0006]    One surgical procedure for the treatment of cataracts, illustrated in  FIGS. 2-4 , is an Extra-Capsular (“ECCE”) surgery that includes capsulorrhexis, or a partial removal of an anterior portion of the capsular bag  30 . While not limiting, the capsulorrhexis may be created by cutting and may have a diameter of approximately 5 mm. The cortex  34  ( FIG. 1 ) and the nucleus  32  ( FIG. 1 ) portions of the lens  24  are removed through the opening, defined by a capsulorrhexis edge  38 , while the remaining portion of the capsular bag  30  is retained. An intraocular lens (“IOL”)  40  then replaces the cortex  34  ( FIG. 1 ) and the nucleus  32  ( FIG. 1 ). 
         [0007]    The IOL  40 , illustrated in greater detail in  FIGS. 4A and 4B  according to one embodiment, includes a transparent, biconvex structure  42  (though other lens structures may be used) constructed from a plastic, silicone, or acrylic material selected to replicate the refractive index and accommodation, or adjustable optical power, of the native lens  24  ( FIG. 1 ). The biconvex structure  42  includes an anterior portion  44  and a posterior portion  46  that converge at a circumferential, lateral edge  48 . While the circumferential edge  48  is specifically illustrated as a lateral wall, it would be understood that the length of the lateral wall may vary and may in fact be an edge of minimal thickness. 
         [0008]    Two diametrically opposed haptic members  50  extend radially outwardly from the biconvex structure  42  and are generally oriented to be planar; however, angulated haptic members are also known and may be used if desired. The haptic members  50  are configured to engage the capsular bag  30  ( FIG. 2 ) and to suspend the IOL  40  at a desired position. While the haptic members  50  are illustrated as radially extending projections, or arms, other embodiments and structures are known to those of ordinary skill in the art. 
         [0009]    During cataract surgery, the placement of the IOL  40  may vary. For example, one conventional surgical method, shown in  FIG. 2 , positions the IOL  40  within the capsular bag  30  such that the haptic members  50  engage an inner surface of the wall of the capsular bag  30  and the IOL  40  is located generally centrally within the capsular bag  30 .  FIG. 3  illustrates an alternative position for the IOL  40 , wherein the IOL  40  positioned within the posterior chamber  18  with the haptic members  50  extending into the ciliary sulcus  52 . 
         [0010]    Positioning the IOL  40  anterior to the capsular bag  30  within the posterior chamber  18  has several potential disadvantages, including possible decentralization of the IOL and/or posterior iris chafing. Thus, placement of the IOL  40  within the capsular bag  30  may be preferred. However, capsular bag fixation may result in negative dysphotopsia (“ND”), which is a visual phenomenon that occurs after an uncomplicated cataract surgery. Symptoms include a shadowing in the temporal field of vision. 
         [0011]    The etiology of ND is unknown, but symptoms may be relieved with a second surgery, known as the piggyback method, which is illustrated in  FIG. 4 . As shown, the conventional piggyback method includes the first IOL, which was previously positioned within the capsular bag  30 , and a second, later positioned IOL, which is placed anterior to the capsular bag  30  as shown in  FIG. 4 . This approach, while improving the symptoms of ND, may again lead to posterior iris chafing. Also, the alternative approach of placing both IOLs within the capsular bag may lead to interlenticular opacification (“ILO”). 
         [0012]    Thus, there exist a need for an IOL and surgical method that provides the benefits of a capsular bag fixation but does not result in ND. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention overcomes the foregoing problems and other shortcomings, drawbacks, and challenges of conventional IOL designs and surgical methods associated with reducing the occurrence of ND. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. To the contrary, this invention includes all alternatives, modifications, and equivalents as may be included within the spirit and scope of the present invention. 
         [0014]    In one embodiment of the present invention, an intraocular lens implant is provided including a lens having an anterior portion, a posterior portion, and a circumferential edge located between the anterior and posterior portions. An annular notch is formed in the anterior portion of the IOL and is oriented in an anteriorly-directed orientation. 
         [0015]    According to another embodiment of the present invention, the IOL includes a lens having an anterior portion, a posterior portion, and a circumferential edge located between the anterior and posterior portions. At least two haptic members extend radially away from the lens and lie within a common plane. An annular notch is formed in the anterior portion of the IOL and is oriented in an anteriorly-directed orientation. 
         [0016]    In yet another embodiment of the present invention, the IOL includes a posterior portion that is configured to reside within the capsular bag within an eye of a patient. An anterior portion of the IOL includes a first portion that is configured to be anterior to the capsular bag and within the ciliary sulcus. A second portion of the anterior portion is configured to reside within the capuslor bag. An annular notch is formed in the IOL, between the first and second portions of the anterior portion, and is configured to receive a capsulorrhexis edge of the capsular bag within the annular notch. 
         [0017]    According to yet another embodiment of the present invention, an IOL is provided having a lens with an anterior portion, a posterior portion, and a circumferential edge between the anterior and posterior portions. An annular notch is formed in the anterior portion of the lens and is configured to capture a capsulorrhexis edge of the capsular bag within the annular notch. 
         [0018]    According to another aspect of the present invention, a method of implanting an intraocular lens within an eye of a patient is provided. The method includes creating a capsulorrhexis within the capsular bag within an eye of a patient. The cortex and the nucleus of the lens are removed from the capsular bag. The intraocular lens is inserted into the capsular bag such that a posterior portion of the lens resides within the capsular bag, a first portion of an anterior portion is located anterior to the capsular bag and resides within the ciliary sulcus, a second portion of the anterior portion is located within the capsular bag, and an annular notch that is formed in the between the first and second portions of the anterior portion captures an edge of the capsulorrhexis within the annular notch. 
         [0019]    The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0020]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
           [0021]      FIG. 1  is a cross-sectional view, in the sagittal plane, through an anterior segment of a healthy human eye. 
           [0022]      FIG. 2  is a cross-sectional view, in the sagittal plane, through an anterior segment of a human eye having an IOL implanted within the capsular bag. 
           [0023]      FIG. 3  is a cross-sectional view, in the sagittal plane, through an anterior segment of a human eye having an IOL implanted within the posterior chamber. 
           [0024]      FIG. 4  is a cross-sectional view, in the sagittal plane, through an anterior segment of a human eye having a piggybacked IOL implant. 
           [0025]      FIG. 5A  is a side-elevational view of one embodiment of a conventional IOL. 
           [0026]      FIG. 5B  is a top view of the IOL of  FIG. 5A . 
           [0027]      FIG. 6A  is a side-elevational view of one embodiment of an IOL in accordance with the present invention. 
           [0028]      FIG. 6B  is a top view of the IOL of  FIG. 6A . 
           [0029]      FIG. 6C  is an enlarged, side-elevational view of the encircled area  6 A of the IOL in  FIG. 6A . 
           [0030]      FIG. 6D  is a cross-sectional view that is similar to  FIG. 6C  and showing an IOL according to an alternative embodiment of the present invention. 
           [0031]      FIG. 7A  is a side-elevational view of another embodiment of an IOL in accordance with the present invention. 
           [0032]      FIG. 7B  is a side-elevational view of yet another embodiment of an IOL in accordance with the present invention. 
           [0033]      FIG. 8  is a cross-sectional view, in the sagittal plane, through an anterior segment of a human eye having the IOL of  FIG. 6  implanted within the capsular bag. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    Turning now to the figures, and to  FIGS. 6A and 6B  in particular, one embodiment of an IOL  60  in accordance with the present invention is shown. While the IOL  60  of  FIGS. 6A and 6B  is shown as a biconvex lens  62  having at least two diametrically opposed haptic members  64 , other lens designs may also be used, including, for example, a convex-concave IOL  60   a  ( FIG. 7A ), a convex-planar IOL  60   b  ( FIG. 7B ), or other designs as desired. The biconvex lens  62  comprises a transparent structure constructed from a polymeric, silicone, acrylic, or other suitable moldable material having a refractive index similar to the native lens  24  ( FIG. 1 ). Anterior and posterior portions  66 ,  68  of the biconvex lens  62  converge at a lateral, circumferential edge  70  of the IOL  60 . As shown, the circumferential edge  70  may be a wall having a length of about 1 mm with an anterior edge  69  and a posterior edge  71 . However, in some embodiments, the anterior and posterior portions  66 ,  68  may converge at a common edge (not shown). When the IOL  60  is biconvex and the anterior portion  66  and the posterior portion  68  converge at this common edge and are substantially similar in size and shape (a symmetric biconvex lens), the circumferential edge  70  may coincide with an equatorial plane; however, the biconvex lens may also be asymmetric, for example, where the anterior portion  66  has a convexity that is greater than a convexity of the posterior portion  68 . 
         [0035]    In some embodiments, the surface of either portion  66 ,  68  of the biconvex lens  62  may be constructed to have uniform optical properties across its diametric surface or it may be constructed as a multi-focal or accommodating lens having two or more zones of differing optical properties. 
         [0036]    The two or more haptic members  64  may extend radially outwardly from the biconvex lens  62  and are generally positioned to lie within a common plane  72  (i.e., are planar) extending through the biconvex lens  62  as shown in  FIG. 6A . Although not shown, the haptic members  64  may also be angulated relative to the common plane  72 . In some embodiments, the common plane  72  is coincident with the circumferential edge  70  of the biconvex lens  62 . That is, the common plane  72  may be substantially co-planar with a diameter of the IOL  60  and positioned between the anterior and posterior edges  69 ,  71 . When the IOL  60  is a symmetric biconvex lens and the anterior and posterior portions  66 ,  68  are similar in size and shape, the biconvex lens  62  is symmetric about the equatorial plane and the common plane  72  may be positioned equidistant from the anterior and posterior edges  69 ,  71  (or at the converged edges of the anterior and posterior portions  66 ,  68 ) at the equatorial plane. 
         [0037]    The haptic members  64  may be constructed from a pliable material, such as a polymer, extruded poly(methyl methacrylate) (“PMMA”), polypropylene, silicone, or acrylic. The pliable material allows the haptic members  64  to be folded for insertion through the capsulorrhexis edge  38  ( FIG. 2 ) and deployment within the capsular bag  30  ( FIG. 1 ). In some embodiments, the haptic members  64  may be constructed from the same material as the biconvex lens  62 , and indeed the IOL  60  may be a unitary structure; however, this is not necessary. In still other embodiments, the haptic members  64  may alternatively be constructed from sturdy treads or filaments that are attached to, or embedded within, the biconvex lens  62  and extend outwardly along the common plane  72 . 
         [0038]    In the specific illustrated embodiment, the haptic members  64  include an enlarged base  74 , adjacent the biconvex lens  62 , with radially extending projections or arms  76 . The radially outward construction of the haptic members  64  is configured to accommodate anatomical size differences of different patients. That is, the inside walls of a capsular bag  30  having a diameter that is smaller than the larger dimension of the IOL (i.e., the diameter extending along the common plane  72  and across the haptic members  64 ) will cause the arms  76  to be deflected radially inwardly. Thus, a larger diameter capsular bag  30  would cause less radially inward deflection of the arms  76  than the smaller diameter capsular bag  30 . 
         [0039]    The biconvex lens  62  in accordance with one embodiment of the present invention includes an annular groove  80  that is positioned anterior to the common plane  72  defined by the haptic members  64 . The annular groove  80  may be positioned anteriorly of the circumferential edge  70 , for example about 0.2 mm to about 1 mm, or alternatively between about 0.25 mm and about 0.75 mm, of the anterior edge  69  of the circumferential edge  70 . 
         [0040]    Furthermore, and as more specifically shown in  FIGS. 6C and 6D , the annular groove  80  includes a posterior wall  80   a  and an anterior wall  80   b . In one embodiment, the posterior wall  80   a  of the annular groove  80  may lie, in cross-section, on a plane that is disposed at a first angle, θ, relative to a horizontal plane (represented by “P”), which may range from about 10° to about 25°. The anterior wall  80   b  of the annular groove  80  may lie, in cross-section, in a plane that is disposed at an angle, φ, relative to the horizontal plane, P, which may range from about 0° (e.g., substantially horizontal) to about 10°. 
         [0041]    While the groove  80  may be specifically configured to the particular anatomical shape as appropriate in order to capture and secure the capsulorrhexis edge  38  ( FIG. 2 ), the particular groove  80  illustrated in  FIG. 6A  extends inwardly into the lens  62  about 0.5 mm. Other dimensions are possible and may depend on the dimensions of the capsulorrhexis preferred by the surgeon. The annular groove  80  may be machined, such as by laser cutting, into the previously molded biconvex lens  62  or may be included during the molding process. 
         [0042]    In use, and with reference now to  FIG. 8 , the surgeon creates the capsulorrhexis within the capsular bag  30  using a punch, a laser, or another appropriate cutting device. While the shape and the diameter of the capsulorrhexis may vary, generally the capsulorrhexis is circular or semi-circular in shape and has a diameter of approximately 5 mm. The surgeon then removes the cortex  34  ( FIG. 1 ) and the nucleus  32  ( FIG. 1 ) of the native lens  24  ( FIG. 1 ) through the capsulorrhexis. The native lens may include a cataract or may be crystalline; however, the method described herein generally refers to cataract surgeries. The IOL  60  is then inserted through the capsulorrhexis and into the capsular bag  30 . Inserting may include deployment of the IOL  60  from a folded state contained within a delivery device, such as a cannula. Otherwise, during insertion, the IOL  60  may capture the capsulorrhexis edge  38 . Alternatively, insertion of the IOL  38  may occur within the volume contained by the capsular bag  30 , and the anterior portion  66  of the IOL  60  having the annular groove  80  therein may be partially retracted through the capsulorrhexis such that the capsulorrhexis edge  38  is captured and retained by the annular groove  80 . The haptic members  64  extend radially within the capsular bag  30  and engage the inner surface of the capsular bag  30 . 
         [0043]    With the surgical process complete, the capsulorrhexis edge  38  is captured by the groove  80  such that a first portion  82  of the anterior portion  66  of the IOL  60  is external to the capsular bag  30  and within the posterior chamber  18  and a second portion  84  of the anterior portion  66  is within the capsular bag  30 . The posterior portion  68  of the IOL and the haptic members  64  are also within the capsular bag  30 . Thus, the patient having cataract surgery in accordance with an embodiment of this invention, would receive the benefits generally achievable by capsular bag placement of the IOL, i.e., reduced occurrence of iris chafing and/or decentralization associated placement of the entire IOL, or a large portion of the IOL, with a posterior chamber  18 . Furthermore, the patient would receive the benefit of reduced of ND. While not wishing to be bound by theory, it is believed that the reduction in ND may be attributed to having an optic edge of the lens cover the capsulorrhexis edge. 
         [0044]    While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in some detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features of the invention may be used alone or in any combination depending on the needs and preferences of the user. This has been a description of the present invention, along with methods of practicing the present invention as currently known. However, the invention itself should only be defined by the appended claims.