Abstract:
A device having a pair of stretcher bars. The first bar remains fixed while the second bar can be reciprocated relative to the first bar by actuation of a movable slide. The device of the present invention is useful for stretching and implanting the ring portion of a two component intraocular lens.

Description:
[0001]     This invention relates to intraocular lenses (IOLs) and more particularly to injectors used to inject IOLs into an eye.  
       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 the 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. Several methods of rolling or folding the lenses are used. One popular method is an injector cartridge that folds the lenses and provides a relatively small diameter lumen through which the lens may be pushed into the eye, usually by a soft tip plunger. The most commonly used injector cartridge design is illustrated in U.S. Pat. No. 4,681,102 (Bartell), and includes a split, longitudinally hinged cartridge. Similar designs are illustrated in U.S. Pat. Nos. 5,494,484 and 5,499,987 (Feingold) and U.S. Pat. Nos. 5,616,148 and 5,620,450 (Eagles, et al.). In an attempt to avoid the claims of U.S. Pat. No. 4,681,102, several solid cartridges have been investigated, see for example U.S. Pat. No. 5,275,604 (Rheinish, et al.) and U.S. Pat. No. 5,653,715 (Reich, et al.).  
         [0005]     These prior art devices used plungers that were substantially symmetrical about a longitudinal axis and generally contained a cylindrical or flared soft tip that completely filled the bore of the injector cartridge. See, for example, U.S. Pat. No. 4,681,102 (Bartell) and U.S. Pat. No. 4,919,130 (Stoy, et al.), and WIPO Publication No. WO 96/29956, the entire contents of which are incorporated herein by reference. Other plungers had hooked or forked tips meant to grasp the edge of the IOL. See for example, U.S. Pat. No. 4,573,998 (Mazzocco), U.S. Pat. Nos. 5,494,484 and 5,499,484 (Feingold), U.S. Pat. Nos. 5,616,148 and 5,620,450 (Eagles, et al.) and U.S. Pat. No. 5,653,715 (Reich, et al.), the entire contents of which are incorporated herein by reference. One plunger tip recently commercially introduced is designed so that the IOL rolls around the tip as the IOL is advanced down the cartridge. See U.S. Pat. No. 5,735,858 (Makker, et al.), the entire contents of which is incorporated herein by reference.  
         [0006]     While these symmetric plunger designs work well, the large tip requires a relatively large incision, usually on the order of 3.0 mm or larger. Accordingly, a need continues to exist for an IOL injector designed to be used with incisions smaller than 3.0 mm.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     The present invention improves upon prior art lens injectors by providing a device having a pair of stretcher bars. The first bar remains fixed while the second bar can be reciprocated relative to the first bar by actuation of a movable slide. The device of the present invention is useful for stretching and implanting the ring portion of a two component intraocular lens.  
         [0008]     It is accordingly an object of the present invention to provide a lens injector having a pair of stretcher bars.  
         [0009]     It is a further object of the present invention to provide a lens injector having a pair of stretcher bars that move relative to each other.  
         [0010]     It is a further object of the present invention to provide a lens injector useful for stretching and implanting the ring portion of a two component intraocular lens.  
         [0011]     Other objects, 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  
       [0012]      FIG. 1  is an enlarged perspective view of the lens injector of the present invention.  
         [0013]      FIG. 2   a  is an enlarged perspective view of a first embodiment of the tip of the lens injector of the present invention taken at circle  2  in  FIG. 1 , showing the stretcher bars in the relaxed position.  
         [0014]      FIG. 2   b  is an enlarged perspective view of a first embodiment of the tip of the lens injector of the present invention taken at circle  2  in  FIG. 1 , showing the stretcher bars in the retracted position.  
         [0015]      FIG. 3  is a side elevational view of a second embodiment of the tip of the lens injector of the present invention.  
         [0016]      FIG. 4  is a bottom plan view of a second embodiment of the tip of the lens injector of the present invention.  
         [0017]      FIG. 5  is a side elevational view of a third embodiment of the tip of the lens injector of the present invention.  
         [0018]      FIG. 6  is a bottom plan view of a third embodiment of the tip of the lens injector of the present invention.  
         [0019]      FIG. 7  is a perspective view of a third embodiment of the tip of the lens injector of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     As best seen in  FIGS. 1, 2   a  and  2   b , intraocular lens injector  10  of the present invention generally consist of handpiece  10  and stretcher bars  14  and  16 . Handpiece  10  contains reciprocating thumb slide  12 , nosepiece  18  and extendable grip  20 . Grip  20  may be extended or retracted so as to fit the hand of the user more comfortable. Stretcher bar  14  is fixed to nosepiece  18  while stretcher bar  16  penetrates through nosepiece  18  and is fixed to thumb slide  12 , so that reciprocation of thumb slide  12  causes corresponding reciprocation of stretcher bar  16  relative to stretcher bar  14 . Thumb slide  12  may be spring biased in either direction and may be operated by means other than manual manipulation, such as electrically or pneumatically. Stretcher bar  14  contains hook  22  and stretcher bar  16  contains hook  24 . Stretcher bars  14  and  16  are preferably made from titanium, stainless steel or thermoplastic.  
         [0021]     As best seen in  FIGS. 2   a  and  2   b , intraocular lens injector  10  is best used in combination with ring component  26  of a multicomponent lens. One suitable lens is described in U.S. patent application Ser. No. 10/618,954, the entire contents of which being incorporated herein by reference and specifically, the description of the lens system on page 3, lines 25-28 and on page 4, lines 1-14 and  FIGS. 1, 2  and  3 . Ring component  26  is held in place in hooks  22  and  24  on stretcher bars  14  and  16 , respectively. Movement of thumb slide  12  causes hook  24  to move toward or away from hook  22 , depending upon the direction of movement of thumb slide  12 . Moving hook  24  away from hook  22  cause ring component  26  to stretch, as seen in  FIG. 2   b . Stretching of ring component  26  causes ring component  26  to become thinner in cross-sectional area. When stretched, ring component  26  may be inserted into an eye through a relatively incision smaller incision, preferably less than 3 mm and more preferably, 2.00 mm or less. As best seen in  FIG. 2   a , stretcher bar  16  contains projection  17 . Projection  17  helps prevent hook  24  from catching on the wound when injector  10  is removed from an eye.  
         [0022]     As best seen in  FIGS. 3 and 4 , stretcher bar  14 ′ may alternatively consist of a hollow tube surrounding stretcher bar  16 ′ so that stretcher bars  14 ′ and  16 ′ are coaxial, and stretcher bar  16 ′ reciprocates within stretcher bars  14 ′ in slot  30  so as to move hooks  22 ′ and  24 ′ closer or father apart. Stretcher bar  16 ′ also contains projection  17 ′.  
         [0023]     As best seen in  FIGS. 5, 6  and  7 , stretcher bar  14 ″ may project out the distal tip of stretcher bar  16 ″. In such a construction, stretcher bar  14 ″ may be fixed so that stretcher bar  16 ″ reciprocates coaxially over stretcher bar  14 ″. Stretcher bar  14 ″ contains hook  22 ″ and stretcher bar  16 ″ contains hook  24 ″ and projection  17 ″ and is otherwise of construction similar to that described above.  
         [0024]     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.