Abstract:
A foldable lens having a plurality of generally “T”-shaped haptics that vault the lens posteriorly when implanted in the eye while still providing stable fixation of the lens within the eye. Such a construction ensures firm contact between the optic and the posterior capsule while still allowing the anterior capsule and the posterior capsule to contact and cause fibrosis about the haptics.

Description:
[0001]    This invention relates to intraocular lenses (IOLs) and more particularly to soft, foldable intraocular lenses.  
         BACKGROUND OF THE INVENTION  
         [0002]    The human eye in its simplest terms functions to provide vision by transmitting and refracting light through a clear outer portion called the cornea, and further focusing the image by way of lens onto the retina at the back of the eye. The quality of the focused image depends on many factors including the size, shape and length of the eye, and the shape and transparency of the cornea and lens.  
           [0003]    When trauma, age or disease cause the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. The treatment for this condition is surgical removal of the lens and implantation of an artificial lens or IOL.  
           [0004]    While early IOLs were made from hard plastic, such as polymethylmethacrylate (PMMA), soft foldable IOLs made from silicone, soft acrylics and hydrogels have become increasingly popular because of the ability to fold or roll these soft lenses and insert them through a smaller incision. While early foldable lenses either had a plate-style haptic (e.g., U.S. Pat. No. 4,664,666 (Barrett), the entire contents of which being incorporated herein by reference) or were of a multi-piece design with independently formed, relatively rigid haptic attached to the soft optic (e.g., U.S. Pat. No. 5,118,452 (Lindsey, et al.), the entire contents of which being incorporated herein by reference), newer lens designs are of an open-loop variety and manufactured from a single piece (e.g., U.S. Pat. No. 5,716,403, (Tran, et al.), the entire contents of which being incorporated herein by reference). The problem with current soft, planar haptic, single-piece, open loop IOLs is that the haptics lack axial force to vault the optic posteriorly away from the iris and ensure firm contact with the posterior capsule. With respect to single piece, closed loop, vaulted soft IOLs, one reference, U.S. Pat. No. 6,409,762 B1 (Pynson, et al.), the entire contents of which being incorporated herein by reference, suggests that such a construction is undesirable due to tilt and unpredictable axial displacement of the lens in the eye.  
           [0005]    Accordingly, a need continues to exist for a vaulted, single-piece, open loop, soft intraocular lens.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    The present invention improves upon prior art single-piece, open loop, soft intraocular lenses by providing a foldable lens having a plurality of generally “T”-shaped haptics that vault the lens posteriorly when implanted in the eye while still providing stable fixation of the lens within the eye. Such a construction ensures firm contact between the optic and the posterior capsule while still allowing the anterior capsule and the posterior capsule to contact and cause fibrosis about the haptics.  
           [0007]    It is accordingly an object of the present invention to provide a stable intraocular lens.  
           [0008]    It is a further object of the present invention to provide a vaulted, single-piece, open loop, soft intraocular lens.  
           [0009]    It is a further object of the present invention to provide a single-piece, open loop, soft intraocular lens having a plurality of generally “T”-shaped haptics that vault the lens posteriorly when implanted in the eye.  
           [0010]    Other objectives, features and advantages of the present invention will become apparent with reference to the drawings, and the following description of the drawings and claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a top plan view of a first embodiment of the intraocular lens of the present invention.  
         [0012]    [0012]FIG. 2 is a side elevational view of a first embodiment of the intraocular lens of the present invention.  
         [0013]    [0013]FIG. 3 is a perspective view a first embodiment of the intraocular lens of the present invention.  
         [0014]    [0014]FIG. 4 is a perspective view a second embodiment of the intraocular lens of the present invention.  
         [0015]    [0015]FIG. 5 is a perspective view a third embodiment of the intraocular lens of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    As best seen in FIGS. 1 and 2, lens  10  generally consists of optic  12  and a plurality of haptics  14 . Optic  12  has an anterior face  18  and a posterior face  16 . Lens  10  may have any suitably designed optic  12  (e.g., multifocal, toric, monofocal) and preferably made in a single piece from a soft, foldable material, such as silicone, hydrogel or soft acrylic and symmetrical about optical axis  11 . Haptics  14  intersects edge  20  of optic  12  at an angle relative to the plane of the optic, preferably between 1° and 20°, and most preferably between 3° and 10° but other suitable angles may also be used. Haptics  14  preferably are generally “T”-shaped in the plane of optic  12 , attached to optic  12  at joints  22  and contain open areas  24  that reduce the mass and increase the flexibility of haptics  14 . Open areas  24  also provide for increased contact between the anterior and posterior capsules once lens  10  is implanted in an eye. In addition, the “T” shape of haptics  14  is places joint  22  in the same radial location as contact point  25  of haptics  14  with the capsule bag, thereby allowing the anterior capsule remnant to fall posteriorly and contact the posterior capsule, possibly reducing the incidence of posterior capsule opacification. As best seen in FIG. 3, haptics  14  are thinner (in the plane parallel to the plane of optic  12 ) in the area around joints  22  than distal portion  23 , and portions  23  are thicker in the plane of optic  12  than in the plane perpendicular to the plane of optic  12 , this assures that haptics  14  will flex at joints  22 , causing lens  10  to vault. In addition, distal portions  23  of haptics  14  are generally scalloped-shaped. This assures that distal portions  23  of haptics  14  will flex inwardly and conform to the shape of the capsular bag. While any suitable dimensions can be used, haptics  14  preferably are between about 0.10 mm and 0.40 mm thick, with around 0.20 mm being most preferred. While lens  10  is illustrated having three haptics  14 , once skilled in the art will recognize that lens  10  may contain two or more haptics  14 , provided that there are sufficient haptics  14  to contact the majority of the equator of the capsular bag along at least 220°. Such a broad area of contact reduces the stress induced by the lens to the capsular bag while keeping the capsular bag in equal tension, thereby minimizing the formation of folds in the capsular bag and helping the capsular bag to keep a round shape. The soft construction of lens  10 , and in particular, joints  22 , allows lens  10  to be compressed by the capsular bag (e.g., to around 10 millimeters), thereby tightening the zonules and facilitating accommodation.  
         [0017]    As best seen in FIG. 4, in a second embodiment of the present invention, lens  110  generally consists of optic  112  and a plurality of haptics  114 . Lens  110  may have any suitably designed optic  112  (e.g., multifocal, toric, monofocal) and preferably made in a single piece from a soft, foldable material, such as silicone, hydrogel or soft acrylic and symmetrical about the optical axis. Haptics  114  intersects edge  120  of optic  112  at an angle relative to the plane of the optic, preferably between 1° and 20°, and most preferably between 3° and 10° but other suitable angles may also be used. Haptics  114  preferably are generally “T”-shaped in the plane of optic  112 , attached to optic  112  at joints  122  and contain open areas  124  that reduce the mass and increase the flexibility of haptics  114 . Open areas  124  also provide for increased contact between the anterior and posterior capsules once lens  110  is implanted in an eye. In addition, the “T” shape of haptics  114  places joint  122  in the same radial location as contact point  125  of haptics  114  with the capsule bag, thereby allowing the anterior capsule remnant to fall posteriorly and contact the posterior capsule, possibly reducing the incidence of posterior capsule opacification. Distal portions  123  of haptics  114  are generally scalloped-shaped. This assures that distal portions  123  of haptics  114  will flex inwardly and conform to the shape of the capsular bag. Lens  110  is generally of the same design and construct as lens  10  except that haptics  114  are of relatively constant thickness from joints  122  to contact points  125 .  
         [0018]    As best seen in FIG. 5, in a third embodiment of the present invention, lens  210  generally consists of optic  212  and a plurality of haptics  214 . Lens  210  may have any suitably designed optic  212  (e.g., multifocal, toric, monofocal) and preferably made in a single piece from a soft, foldable material, such as silicone, hydrogel or soft acrylic and symmetrical about the optical axis. Haptics  214  intersects edge  220  of optic  212  at an angle relative to the plane of the optic, preferably between 1° and 20°, and most preferably between 3° and 10° but other suitable angles may also be used. Haptics  214  preferably are generally “T”-shaped in the plane of optic  212 , attached to optic  212  at joints  222  and are thinner (in the plane of optic  212 ) in the area around joints  222  than distal portion  223 , and portions  223  are thicker in the plane of optic  212  than in the plane perpendicular to the plane of optic  212 . This assures that haptics  214  will flex at joints  222 , causing lens  210  to vault, and that distal portions  223  of haptics  214  will flex inwardly and conform to the shape of the capsular bag. In addition, the “T” shape of haptics  214  places joint  222  in the same radial location as contact point  225  of haptics  214  with the capsule bag, thereby allowing the anterior capsule remnant to fall posteriorly and contact the posterior capsule, possibly reducing the incidence of posterior capsule opacification. Distal portions  223  of haptics  214  are generally scalloped-shaped. This assures that distal portions  223  of haptics  214  will flex inwardly and conform to the shape of the capsular bag. Lens  210  is generally of the same design and construct as lens  10  except that haptics  214  do not contain open areas  24 .  
         [0019]    While certain embodiments of the present invention have been described above, these descriptions are given for purposes of illustration and explanation. Variations, changes, modifications, and departures from the systems and methods disclosed above may be adopted without departure from the scope or spirit of the present invention.