Abstract:
A plate haptic is used with an intraocular lens optic displaceable in response to vitreous pressure changes. The plate haptic comprises: a plurality of opposing lateral portions; a distal portion having a plurality of opposing projections extending substantially laterally therefrom; and a proximal portion comprising a strap across which is a hinge connecting the lens optic to the haptic. The intersection of the proximal portion with each lateral portion forms a plurality of appendages, or paddles, to partially surround the optic. The appendages, projections, and hinged straps combine to substantially aid displacement of the lens optic in response to changes in vitreous pressure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based on and claims the benefit of the filing of U.S. Provisional Patent Application No. 61/398,107, filed Jun. 21, 2010; U.S. Provisional Patent Application No. 61/398,098, filed Jun. 21, 2010; U.S. Provisional Patent Application No. 61/398,115, filed Jun. 21, 2010; and U.S. Provisional Patent Application No. 61/398,099, filed Jun. 21, 2010, the contents and disclosure of which are fully incorporated herein by reference. 
         [0002]    This application is related to U.S. Non-Provisional Patent Application No. 13/017,189, filed Feb. 14, 2011, the contents and disclosure of which is fully incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0003]    Accommodating Intraocular Lenses were developed in the early 1900&#39;s and have been sold in Europe for the last ten years and later in the U.S. They function by means of forward movement of the optic upon constriction of the ciliary muscle which increases the pressure in the posterior part of the eye with a simultaneous decrease in pressure in the front part of the eye pressure. The reverse pressure changes take place upon relaxation of the ciliary muscle, which results in the backwards movement of the lens for distance vision. The forward movement of the lens optic enables the patient implanted with the lens to automatically change their vision from distance to see at intermediate and near. 
         [0004]    The first intraocular lenses developed by Harold Ridley were implanted in patients at St. Thomas&#39; Hospital in London in 1949. The lenses were made of “perspex” (polymethylmethacrylate) and were large, heavy, rigid and biconvex. The complication rate was high since the specific gravity of PMMA was heavier than that of the aqueous that they were surrounded by, and they tended to de-center, or dislocate. This was just one of the complications of this first design. These lenses were placed in the eye behind the iris and in front of the posterior capsule of the human lens after the cataract had been removed, leaving behind the posterior capsule. 
         [0005]    Subsequent lens designs by Epstein, Binkhorst and Worst attached the lens to the iris. This, along with anterior chamber lenses reduced the complication rate but it was not until Shearing developed a lens to be implanted into the empty capsular bag, putting the lens optic, once again back where it belonged, behind the iris, that there was a significant reduction in complications. This posterior chamber lens design was the first to have open loops attached to the optic, which helped to center and fixate the lens within the capsular bag by capturing the loops within the bag by means of fibrosis of the anterior capsule remnants to the posterior capsule over the flexible loops. These loops were called haptics. 
         [0006]    Many iterations of this design followed. All the optics of these lenses were made of rigid PMMA. In the 1970&#39;s Mazzocco developed a single piece posterior chamber lens made from silicone that could be folded. This lens was molded as one piece, had no loops, and had what are now called “plate haptics”, which replaced the loops. At the time phacoemulsification had been developed and the cataract could be extracted through a 3-4 mm incision. However, since the earlier lenses had been made of rigid PMMA and had an optic diameter of 5-6 mm, the wound had to be enlarged to allow the lens to be inserted into the eye and had to be sutured. The advent of Mazzocco&#39;s foldable lens changed all this. It enabled foldable lenses to be inserted into the eye, folded, through a 3-4 mm tunnel incision, that now needs no suturing. 
         [0007]    The word “haptic” has been used to describe an attachment to intraocular lenses. The original intraocular lens consisted of a single optic. These lenses frequently de-centered. It was discovered that there was a need to center and fixate the lens optic in the vertical meridian of the eye. The first attachments to the optic were called “haptics”. They consisted of multiple flexible loops of various designs, J loops, C loops, closed loops and flexible radial arms. 
         [0008]    Later, these loops which became commonly referred to as “haptics” were replaced in some lens designs with flat homogeneous plates, called “plate haptics”. The plate haptic design has two main advantages over loop lenses. First, if they have a plate length of 10.5 to 11.5 mm they vault backwards when confined within the approximate 10.5 mm diameter and 5.0 mm deep space that remains within the human capsular bag after extracting the cataract. Second, their location along the axis of the eye is more consistent than that of loop lenses. These two properties of plate lenses reduce the incidence of the major post-operative complications of cataract surgery, which are retinal detachments and cystoid macular edema, and because of the more consistent location of the lens optic along the axis of the eye, the uncorrected post-operative visual acuities are superior to those of loop lenses. 
         [0009]    During constriction of the circular ciliary muscle its diameter decreases and it compresses distal ends of opposing plate haptics which then move centrally. Since the uni-planar plate haptics tend to naturally vault posteriorly when placed within the capsular bag the proximal end of the plates attached to the lens optic move posteriorly. This posterior movement helps to increase the vitreous cavity pressure behind the lens and the lens optic, and pushes the lens optic anteriorly. This increase in vitreous cavity pressure, with a simultaneous decrease in pressure in the anterior chamber of the eye is a natural occurrence in the human eye with accommodation to see at near. However, due to its construction, the lens optic of a traditional plate haptic lens is limited in its response to the change in vitreous pressure. 
         [0010]    Furthermore, when a plate haptic lens is placed within the capsular bag of the eye the peripheral circumferential remains of the anterior capsule and the posterior capsule of the human capsular bag, fibrose over the distal ends of the plates. The area of fibrosis can vary and sometimes covers only the distal 1.0 mm of the tip of the plate. With inadequate coverage of the distal ends of the plates the plate haptics can sometimes dislocate, one of the plates vaulting forwards to configure the lens in a “Z” shape configuration. 
       SUMMARY OF THE INVENTION 
       [0011]    An accommodating intraocular lens design according to an embodiment of the present invention is described that overcomes the deficiencies of present designs noted above. 
         [0012]    A flat, longitudinal accommodating intraocular lens is provided, having distinct separate plate haptics partially surrounding a lens optic. 
         [0013]    By extending the lateral surface area of the plates adjacent the optic to partially surround the optic, the haptic presses posteriorly on the vitreous immediately adjacent to and almost surrounding the lens optic. The extended part of the plate increases the area of contact of the plate haptic with the vitreous face, on either side of the optic and enhances the effect of the pressure changes within the eye that occur naturally with constriction and relaxation of the ciliary muscle that occurs with accommodation. 
         [0014]    A second feature of this plate design is a small triangular extension of distal-lateral ends of the plate haptics, thereby widening the distal end of the plate haptic by 0.75-1.5 mm on either side of each plate haptic. This allows for a greater area of contact between the fibrosed capsule and the tip of the plates to reduce the incidence and complication of “Z” formations. 
         [0015]    Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described apparatus and method of its use. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0016]    Illustrated in the accompanying drawing(s) is at least one of the best mode embodiments of the present invention In such drawing(s): 
           [0017]      FIG. 1  illustrates a top view of a vitreous compressing plate haptic according to an embodiment of the present invention; 
           [0018]      FIG. 2  illustrates a top view of a vitreous compressing plate haptic according to an embodiment of the present invention; 
           [0019]      FIG. 3  illustrates a top view of a vitreous compressing plate haptic according to an embodiment of the present invention; and 
           [0020]      FIG. 4  illustrates a top view of a vitreous compressing plate haptic according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    The above described drawing figures illustrate the described invention and method of use in at least one of its preferred, best mode embodiment, which is further defined in detail in the following description. Those having ordinary skill in the art may be able to make alterations and modifications to what is described herein without departing from its spirit and scope. Therefore, it should be understood that what is illustrated is set forth only for the purposes of example and should not be taken as a limitation on the scope of the present apparatus and its method of use. 
         [0022]    As illustrated in  FIG. 1 , an intraocular accommodating lens may comprise at least one plate haptic  10  and a lens optic  20 . 
         [0023]    The plate haptic  10  may comprise a distal portion  12 , opposing lateral portions  14 , and a proximal portion  16 . In at least one preferred embodiment, the plate haptic  10  may be substantially or partially constructed of flexible material, such as silicone, acrylic, hydrogel, and/or similar materials known in the art. 
         [0024]    The plate haptic  10  may be of solid, unitary construction, and may have tapered, rounded or parallel edges. In some embodiments, the plate haptic  10  may be between 5.0 and 6.0 mm in width, and between 0.2 to 0.75 mm in thickness. Preferably, the longitudinal length or circumference diameter of the plate haptic  10  may be between 10.0 to 12.0 mm. 
         [0025]    The lens optic  20  may comprise a periphery  22  and a transverse diameter defined by points A and B, as shown in  FIGS. 2 and 3 . In at lease one preferred embodiment, the proximal portion  16  is substantially parallel to the periphery  22  and contoured thereto. In at least one preferred embodiment, the lens optic  20  comprises at least one of: solid, single, multifocal, Fresnell, toric, biconvex, plano-convex refractive, diffractive or liquid filled optics. In at least one preferred embodiment, the lens optic  20  may be substantially or partially constructed of flexible material, such as silicone, acrylic, hydrogel, and/or similar materials known in the art. 
         [0026]    As illustrated in  FIG. 2 , in at least one preferred embodiment, the plate haptic  10  may comprise a chassis  18 . The chassis  18  may be operable to permit flexion of the plate haptic  10  in the longitudinal direction and to substantially resist and prevent flexion of the plate haptic  10  in the transverse direction. This discriminatory flexion permits the lens to be inserted into an eye in a compact state while resisting bending in response to vitreous pressure from the eye once it is inserted. 
         [0027]    In at least one preferred embodiment, the chassis  18  may be a semi-rigid chassis  18  constructed of at least one of: silicone, acrylic, hydrogel, polyamide, prolene, PMMA and titanium. It should be observed that according to at least one preferred embodiment, the chassis  18  may be constructed of the same material as either or both of the plate haptic  10  and the lens optic  20 . In some embodiments, the chassis  18  may consist of portions of increased thickness of the plate haptic  10 . In shape, the chassis  18  preferably comprises an irregular web throughout the plate haptic  10 , however, regular and repeated frame elements are specifically contemplated. 
         [0028]    In at least one preferred embodiment, the proximal portion  16  of the plate haptic  10  comprises a flexible junction  40  connecting the lens optic  20  to the plate haptic  10 , as shown in  FIGS. 1-2 . The flexible junction  40  may be operable to reduce the resistance of the lens optic  20  to a change in vitreous cavity pressure, thereby allowing more movement of the lens optic  20  along the axis of the eye. 
         [0029]    The flexible junction  40  may comprise a single strap, or may comprise a plurality of spaced apart flexible straps. The strap or straps may extend substantially longitudinally from the proximal portion  16  of the plate haptic  10  and connect the plate haptic  10  to the periphery  22  of the lens optic  20 . Alternatively, the strap or straps may extend substantially radially from the periphery  22  of the lens optic  20  and connect the lens optic  20  to the proximal portion  16  of the plate haptic  10 . As illustrated in  FIG. 1 , each strap may have one or more hinges  50  laterally traversing the strap and weakening the strap  40  so as to promote stretching and flexion thereat. The hinge may consist of a single groove. Alternatively, the hinge may consist of two or more directly or indirectly opposing grooves. 
         [0030]    Returning to  FIG. 1 , in at least one preferred embodiment, each lateral portion  14  along with the proximal portion  16  forms an appendage  30 . Thus, the plate haptic  10  may comprise a plurality of appendages  30 , and preferably comprises two appendages  30  that together partially surround the lens optic  20 . The appendage may be paddle shaped but is not limited thereto and should be understood through its functionality. As the ciliary muscle contracts it exerts an inwardly radial end-to-end pressure on opposing plate haptics  10  which are then forced centrally and posteriorly. Because the appendages  30  partially surround the optic  20 , increased pressure is exerted by the vitreous cavity, thereby increasing displacement of the lens optic  20  along the axis of the eye. 
         [0031]    In some embodiments, the appendages  30  may extend from the proximal portion  16  at an angle that is substantially between complete lateral extension and complete longitudinal extension. Alternatively, as shown in  FIG. 4 , the appendages  30  may extend from the proximal portion  16  at an angle that is substantially longitudinal. In at least one preferred embodiment, the appendages  30  are positioned substantially more laterally than the straps. 
         [0032]    Turning now to  FIG. 3 , in some embodiments, the lateral extension of the appendages  30  may be greater than the transverse diameter of the lens optic  20 . In other words, the appendage may extend out beyond an imaginary line tangent to the lateral most point(s) of the lens optic  20  periphery  22 . In some embodiments, the lateral extension of the appendages  30  may be such that the lateral portions  14  are substantially co-extensive with the transverse diameter of the lens optic  20 , as shown in  FIG. 4 . 
         [0033]    As discussed above, each appendage  30  is formed of the lateral portion  14  and proximal portion  16 . In some embodiments, the lateral portions  14  of opposing appendages  30  may be substantially non-convergent. In other words, the lateral portion  14  may be approximated by lines which, if extended roughly in the direction of the lens optic  20 , would be substantially non-convergent. In at least one preferred embodiment, the lateral portion  14  may be substantially divergent, as shown in  FIG. 3 . In at least one preferred embodiment, they may be substantially parallel, as shown in  FIG. 4 . 
         [0034]    The appendages  30  may be of any shape that substantially extends the contact area of the plate haptic  10  with the capsular bag thereby increasing vitreous pressure response. As illustrated in  FIG. 4 , in at least one preferred embodiments, the appendage  30  may be partially triangular in shape—the lateral portion  14  and proximal portion  16  comprising two sides of a triangle. As illustrated in  FIGS. 1-3 , in at least one other preferred embodiment the appendage  30  may be curved and may be partially elliptical in shape. For example, the appendage may be substantially paddle, or tear-drop shaped—the lateral portion  14  and proximal portion  16  approximating the curve. In some embodiments, the appendage  30  may be between 2.0 to 7.0 mm in width. In some embodiments, the appendage  30  may be between 0.02 to 0.75 mm in thickness. 
         [0035]    The appendages  30  may be of fully or partially rigid construction. In some embodiments, the appendages  30  are partially or wholly constructed of flexible material such as: silicone, acrylic, hydrogel, and the like. In some embodiments the appendages  30  are partially or wholly constructed of substantially rigid or semi-rigid material such as: polyamide, prolene, PMMA, titanium and the like. In some embodiments, the appendages  30  at least partially include at least a portion of the chassis  18 , as shown in  FIG. 2 . 
         [0036]    Turning now to  FIGS. 1-4 , in at least one preferred embodiment, the distal end is convex so as to increase a contact surface area. Furthermore, in at least one preferred embodiment, each lateral portion  14  along with the distal portion  12  forms a projection  60 , as shown in  FIGS. 1-2  and  4 . Thus, the plate haptic  10  may comprise a plurality of projections  60 , and preferably comprises two projections  60  that may extend substantially laterally from the distal portion  12 . The projections  60  may further increase the area of contact between the distal portion  12  of the plate haptic  10  and the capsular bag of the eye. Preferably, the projections  60 , in combination with the distal portion  12  may substantially occupy the cul de sac of the capsular bag. In at least one embodiment, the projections  60  may be partially triangular, elliptical, curved, or of any shape operable to increase the contact area. The projections  60  may also comprise a portion of the chassis  18 , as shown in  FIG. 2 . 
         [0037]    In at least one embodiment, the intraocular accommodating lens comprises a plurality, and preferably a pair, of opposing plate haptics  10 , each connected to the lens at respective flexible junctions  40 . In some embodiments, however, the intraocular accommodating lens comprises a single plate haptic  10  opposing a non-plate haptic  10  of a type known in the art. 
         [0038]    The enablements described in detail above are considered novel over the prior art of record and are considered critical to the operation of at least one aspect of the invention and to the achievement of the above described objectives. The words used in this specification to describe the instant embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification: structure, material or acts beyond the scope of the commonly defined meanings Thus if an element can be understood in the context of this specification as including more than one meaning, then its use must be understood as being generic to all possible meanings supported by the specification and by the word or words describing the element. 
         [0039]    The definitions of the words or drawing elements described herein are meant to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements described and its various embodiments or that a single element may be substituted for two or more elements in a claim. 
         [0040]    Changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalents within the scope intended and its various embodiments. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. This disclosure is thus meant to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted, and also what incorporates the essential ideas. 
         [0041]    The scope of this description is to be interpreted only in conjunction with the appended claims and it is made clear, here, that the named inventor believes that the claimed subject matter is what is intended to be patented.