Abstract:
An accommodating intraocular lens (AIOL) ( 10 ) characterised by a first member ( 1 ) and a second member ( 3 ) arranged to correspond to anterior and posterior portions of a capsular bag, having an anterior-posterior axis passing centrally through the first and second members ( 1, 3 ), the first and second members ( 1, 3 ) being connected by one or more link members ( 2 ), a lens structure ( 4 ) including an inflatable lens ( 21 ), and a reservoir ( 23 ) of filling fluid ( 12 ) in fluid communication with the inflatable lens ( 21 ) through one or more channels ( 22 ), wherein axial movement of one of the first and second members ( 1, 3 ) along the anterior-posterior axis applies a pumping force to cause the filling fluid ( 12 ) to flow between the reservoir ( 23 ) and the inflatable lens ( 21 ).

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to accommodating intraocular lenses. 
       BACKGROUND OF THE INVENTION 
       [0002]    Intraocular lenses (IOLs) have been in use for more than 60 years as an implanted replacement for the natural lens in the human eye after cataract surgery. Until about the age of 40, the natural lens can change its curvature shape, and as a result its optical power, for sharp vision of far and near objects in a process called accommodation. 
         [0003]    Many ideas for accommodating intraocular lenses (AIOLs) have been proposed in recent years but none of them attain the required level of accommodation to enable vision without glasses after cataract surgery. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention seeks to provide an improved accommodating intraocular lens, as is described more in detail hereinbelow. 
         [0005]    There is provided in accordance with an embodiment of the present invention an accommodating intraocular lens (AIOL) including an anterior haptic member and a posterior haptic member arranged to correspond to anterior and posterior portions of a capsular bag, having an anterior-posterior axis passing centrally through the anterior and posterior haptic members, an optic including an inflatable member, and a reservoir of fluid in fluid communication with at least one of the anterior and posterior haptic members and with the inflatable member, wherein axial movement of one of the anterior and posterior haptic members along the anterior-posterior axis applies a pumping force to cause fluid to flow between the reservoir and the inflatable member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: 
           [0007]      FIGS. 1A and 1B  are simplified perspective illustrations of an accommodating intraocular lens (AIOL), constructed and operative in accordance with an embodiment of the present invention, respectively in an accommodated state (near vision) with a membrane inflated, and an un-accommodated state (far vision) with the membrane deflated; 
           [0008]      FIGS. 2A and 2B  are simplified side illustrations of the AIOL, in respective accommodated and un-accommodated states in the capsular bag; 
           [0009]      FIGS. 3A-3G  are simplified perspective, top, perspective, side, side sectional, side and top illustrations, respectively, of the lens structure of the AIOL, in accordance with an embodiment of the present invention; 
           [0010]      FIG. 4  is a simplified sectional illustration of the frame and lens structure of the AIOL, in accordance with an embodiment of the present invention; 
           [0011]      FIGS. 5A-5D  are simplified front, side sectional, top and perspective illustrations, respectively, of the AIOL, in the accommodated state; 
           [0012]      FIGS. 5E-5H  are simplified front, side, top and perspective illustrations, respectively, of the AIOL, in the un-accommodated state; 
           [0013]      FIGS. 6A-6D  are simplified front, side sectional, top and perspective illustrations, respectively, of the AIOL, in the accommodated state, in accordance with another embodiment of the present invention; 
           [0014]      FIGS. 6E-6H  are simplified front, side sectional, top and perspective illustrations, respectively, of the AIOL, in the un-accommodated state, in accordance with another embodiment of the present invention; 
           [0015]      FIGS. 7A-7D  and  8 A- 8 D are simplified front, side sectional, top and perspective illustrations, respectively, of other accommodating intraocular lenses, constructed and operative in accordance with other embodiments of the present invention; 
           [0016]      FIGS. 9A-9B  are simplified top illustrations of an accommodating intraocular lens, constructed and operative in accordance with an embodiment of the present invention, with two different alternative ring (haptic) structures; 
           [0017]      FIGS. 10A-10F  are simplified front, side sectional, top, perspective, front and side sectional illustrations, respectively, of accommodating intraocular lenses, constructed and operative in accordance with other embodiments of the present invention, wherein the AIOL is placeable on top of another non-accommodating IOL; 
           [0018]      FIGS. 11A-11D  are simplified front, side, top and perspective illustrations, respectively, of an AIOL, in the accommodated state, in accordance with another embodiment of the present invention; 
           [0019]      FIGS. 12A-12D  are simplified front, side, top and perspective illustrations, respectively, of the AIOL of  FIGS. 11A-11D , in the un-accommodated state; 
           [0020]      FIGS. 13A-13D  are simplified top, perspective, front and side illustrations, respectively, of the AIOL of  FIGS. 11A-11D , installed in an eye in the accommodated state; 
           [0021]      FIGS. 14A-14D  are simplified top, perspective, front and side illustrations, respectively, of the AIOL of  FIGS. 11A-11D , installed in an eye in the un-accommodated state; 
           [0022]      FIGS. 15A-15B  are simplified side and sectional illustrations, respectively, of the AIOL of  FIGS. 11A-11D , in the un-accommodated state; 
           [0023]      FIGS. 16A-16D  are simplified front, side, top and perspective illustrations, respectively, of the lens structure, includes a solid lens and an inflatable lens (membrane), of the AIOL of  FIGS. 11A-11D , in the un-accommodated state; 
           [0024]      FIGS. 17A-17D  are simplified front, side, top and perspective illustrations, respectively, of an AIOL, in the accommodated state, in accordance with yet another embodiment of the present invention; 
           [0025]      FIGS. 18A-18D  are simplified front, side, top and perspective illustrations, respectively, of the AIOL of  FIGS. 17A-17D , in the un-accommodated state; 
           [0026]      FIGS. 19A-19D  are simplified front, side, top and perspective illustrations, respectively, of an AIOL, in the accommodated state, in accordance with still another embodiment of the present invention; and 
           [0027]      FIGS. 20A-20D  are simplified front, side, top and perspective illustrations, respectively, of the AIOL of  FIGS. 19A-19D , in the un-accommodated state. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0028]    Reference is now made to  FIGS. 1A and 1B , which illustrate an accommodating intraocular lens (AIOL)  10 , constructed and operative in accordance with an embodiment of the present invention. 
         [0029]    The AIOL  10  includes a frame structure constructed of a first portion  1  and a second portion  3  connected to one another by one or more link members  2 . First and second portions  1  and  3  are adapted to sit in the anterior and posterior portions, respectively, of the capsular bag (not shown) after removal of the natural lens. (Alternatively the first portion can be the posterior portion and the second portion can be the anterior portion of the AIOL as installed in the eye.) First and second portions  1  and  3  serve as the haptics the hold the AIOL  10  in the bag; alternatively other haptic structures, such as curved wires or plate haptics, for example, may be added to protrude from first and second portions  1  and  3 . 
         [0030]    The second portion  3  includes a lens structure  4  that includes a solid lens  11  with the required optical power to reach clear vision and an inflatable lens (membrane)  21  (e.g., about 2-3 mm in diameter), preferably, but not necessarily, at the central part of the lens  11 . Alternatively, lens structure  4  can include just the inflatable lens  21 . 
         [0031]    Inflatable lens  21  is constructed of a material with sufficient resilience that enables it to expand and increase its convexity upon filling with a filling fluid and contract and decrease its convexity upon evacuation therefrom of the filling fluid. Solid lens  11  is preferably stiffer than inflatable lens  21 , but alternatively, can be of the same stiffness as inflatable lens  21 . The term “stiffness” refers to the amount of elastic deformation a material undergoes when subjected to a given amount of force: the less elastic deformation the material undergoes due to a given force, the stiffer the material. Lens  21  may be spheric, aspheric, toric or other types of optics. 
         [0032]    In one embodiment of the invention, solid lens  11  and inflatable lens  21  are both made of materials that belong to the same class of polymeric materials and are derived from monomers which are mutually compatible, allowing the materials to be co-cured and/or bonded, for example chemically bonded or otherwise joined, to one another. For example, these materials include, without limitation, acrylic polymeric materials, cross-linked acrylic materials, copolymers of methacrylate and acrylate esters cross-linked with one or more functional acrylate/methacrylate cross-linking components, hydrogels, (e.g., hydroxyethyl methacrylate (HEMA) polymer or methyl methacrylate/N-vinyl pyrrolidone (MMA/NVP) copolymer or the like), silicon-containing polymeric materials, such as hydrophobic and hydrophilic silicone, and others. 
         [0033]    In another embodiment, solid lens  11  may be constructed of a different material than inflatable lens  21 , such as but not limited to, polymethylmethacrylate (PMMA), collagen, hydrogel, hyaluronic acid, polysulfones, thermolabile materials and other relatively hard or relatively soft and flexible biologically inert optical materials. 
         [0034]    A reservoir  23  containing filling fluid  12  (such as but not limited to, water, saline solution, oil, silicone oil and other medically approved liquids, air or other gas, gel or others) is located at the periphery of second portion  3 . A chamber  25  ( FIG. 4 ) is located between solid lens  11  and inflatable lens  21 . One or more channels  22  fluidly connect reservoir  23  to chamber  25 . A resilient pedal  14  overlies an anterior portion of reservoir  23 . Pedal  14  can be a pad located on top of reservoir  23  or a membrane covering reservoir  23 , for example, made of a resilient material or relatively stiffer material or combination thereof. A leg  16  at an end of link member  2  near the second portion  3  is positioned over pedal  14 . Leg  16  of link member  2  and pedal  14  together form a pumping device  24  to pump filling fluid  12  to inflate inflatable lens  21 , as is now described. Reservoir  23  is also considered part of the pumping device  24 . Other pumping devices may also be used, examples of which are described further below. Lens  21  may be sufficiently stiff to apply a force on the filling fluid  12  to cause the filling fluid  12  to flow back to reservoir  23 . 
         [0035]    AIOL  10  fills the capsular bag and restores it or nearly restores it, to its volumetric state before removal of the natural lens. Without wishing to be limited to any particular theory of operation, it is believed that accommodative forces are exerted on AIOL  10  by the zonules, ciliary muscles, and capsular bag. These accommodative forces cause axial translation (i.e., along the anterior-posterior directions) of the first and second portions  1  and  3  (that is, first portion  1  moves towards or away from second portion  3 , or second portion  3  moves towards or away from first portion  1 , or a combination of movement towards or away from each other). 
         [0036]    In the position shown in  FIGS. 1A ,  2 A,  4 ,  5 A- 5 D and  6 A, the first and second portions  1  and  3  are axially further from one another. The relative axial translation of the first and second portions  1  and  3  away from each other causes link members  2  to become straightened or at least less bent. As link member  2  straightens (becomes less bent), the leg  16  of link member  2  pushes on pedal  14  and pumps the filling fluid  12  out of reservoir  23  through channels  22  to chamber  25  to inflate (expand) inflatable lens  21 . This is the position for focusing on near objects (near vision). 
         [0037]    Conversely (as seen in  FIGS. 1B ,  2 B,  5 E- 5 H and  6 B), relative axial translation of the first and second portions  1  and  3  towards each other causes flexure (bending) of link members  2 , such as at hinges  18  formed in link members  2 . (Without being bound by any theory, this may occur upon contraction of the capsular bag due to ciliary muscle relaxation, which stretches the capsular bag towards the capsule equator and decrease the distance between the poles.) As link member  2  flexes (bends), the leg  16  of link member  2  comes off pedal  14  Filling fluid  12  flows out of chamber  25  through channels  22  to reservoir  23 , thereby deflating inflatable lens  21 . This is the position for focusing on far objects (far vision). 
         [0038]    Thus, the optical power of the center part of the combined structure is altered and increased by extra diopters. These extra diopters add to the lens power and enable the patient to have sharp near vision. The lens structure of the invention can have the required optical power for sharp distance vision for a patient undergoing refracting lens exchange (RLE) usually as part of cataract surgery. Lens power may be, without limitation, around +20 diopters. 
         [0039]    It is noted that since during the accommodation process the pupil diameter decreases, it may be sufficient to limit the curvature change of lens  21  over a sub-portion of the lens surface with a diameter of about 2-3 mm and no need to make the curvature change over the entire lens surface of lens  21 , which may typically be about 4-6 mm This is a huge advantage that simplifies the design, however, the invention is not limited to this sub-portion of the lens surface. 
         [0040]    In the non-accommodating state (far vision) the membrane of inflatable lens  21  may have almost the same curvature as the anterior surface of the solid lens  11 . 
         [0041]    A port  33  (shown optionally in  FIG. 3C , but applicable for all embodiments) may be provided for filling the reservoir  23  with the filling fluid  12  during production and/or in another procedure, also allowing power adjustment and/or refilling. AIOL  10  can have different devices and/or structures for altering power of both lenses prior, during and after implantation. 
         [0042]    Two or more lens can be provided in the structure for obtaining different optical effects. Any number of channels and link members may be used, with different shapes and positions. The solid lens  11  and inflatable lens  21  may have the same index of refraction, or alternatively, different indices of refraction. 
         [0043]    The invention eliminates the risk of having liquid in a chamber in the eye since a very small volume of filling fluid is needed (e.g., about 0.5 mm 3 ) for creating the accommodation. 
         [0044]    Reference is now made to  FIGS. 7A-7D  and  8 A- 8 D, which illustrate other accommodating intraocular lenses, constructed and operative in accordance with other embodiments of the present invention. The operating principles are the same as described above. In the embodiment of  FIGS. 7A-7D , there are three separate reservoirs  37  spaced equally apart. In the embodiment of  FIGS. 8A-8D , the reservoir is a single annular reservoir  38 . 
         [0045]    Reference is now made to  FIGS. 9A-9B , which illustrate an accommodating intraocular lens, constructed and operative in accordance with an embodiment of the present invention. This embodiment has three axi-symmetrical winged haptics  90  extending from either or both of first and second portions of the AIOL. These haptics may help support the anterior and posterior parts of the capsular bag to retain the desired shape of the bag. This may help exploit the forces and movements of the eye structure during the accommodation process. Of course, the invention may include any number of haptics, winged or not. 
         [0046]    Reference is now made to  FIGS. 10A-10F , which illustrate accommodating intraocular lenses, constructed and operative in accordance with other embodiments of the present invention. In this embodiment, grooves (openings)  41  are formed on a surface of one or both of the first and second portions of the AIOL. This enables placing the AIOL on top of another non-accommodating IOL. 
         [0047]    Reference is now made to  FIGS. 11A-15B , which illustrate an AIOL  50 , constructed and operative in accordance with another embodiment of the present invention. Like elements are labeled with like numerals. This embodiment has four (any other number is also possible) axi-symmetrical winged haptics  52  extending from first portion  1  of the AIOL  50 . Additionally or alternatively they could extend from the second portion  3 . Haptic  52  has a radially-outward curved contour  54  for better matching the shape of the capsular bag. Haptic  52  has a cutout portion  56  to reduce weight and so as not to block tissue in the eye. Link members  2  also have cutout portions  58  formed therein on either side of hinge  18 . 
         [0048]    Reference is now made to  FIGS. 16A-16D , which illustrate the lens structure of the embodiment of  FIGS. 11A-15B . In this embodiment, there are serpentine or S-shaped channels  60 . Other shapes may also be used. 
         [0049]    Reference is now made to  FIGS. 17A-18D , which illustrate an AIOL  70 , constructed and operative in accordance with yet another embodiment of the present invention. In this embodiment, there is a reservoir  71  in the leg (lower leg) of one or more of link members  72 , and reservoir  71  contracts and expands with movement of the link members  72 , which is the pumping action. When the first and second portions  1  and  3  are moved away from one another for near vision, the filling fluid flows from reservoir  71  to inflatable lens  21 ; reservoir  71  is squeezed (contracted) by this action, thereby pumping fluid from it to the lens  21 . Conversely, when the first and second portions  1  and  3  are moved towards one another for far vision, the filling fluid flows from inflatable lens  21  to reservoir  71 ; reservoir  71  expands as it is filled with the fluid flowing from lens  21 . 
         [0050]    Reference is now made to  FIGS. 19A-20D , which illustrate an AIOL  80 , constructed and operative in accordance with still another embodiment of the present invention. In this embodiment, there is a reservoir  81  formed in an inner space of a link member  82 , and reservoir  81  contracts and expands with movement (flexure) of the link members  82 , which is the pumping action. When the first and second portions  1  and  3  are moved away from one another for near vision, the filling fluid flows from reservoir  81  to inflatable lens  21 ; reservoir  81  is contracted by this action, thereby pumping fluid from it to the lens  21 . Conversely, when the first and second portions  1  and  3  are moved towards one another for far vision, the filling fluid flows from inflatable lens  21  to reservoir  81 ; reservoir  81  expands as it is filled with the fluid flowing from lens  21 . 
         [0051]    It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.