Abstract:
An intraocular lens injector for injecting a foldable intraocular lens in an aye, comprises: a substantially cylindrical main unit including a substantially cylindrical insertion part which is insertable through an incision made in the eye, the main unit being adapted to internally hold the intraocular lens and release the intraocular lens to the outside of the injector through the insertion part; a push unit inserted in the main unit to push the intraocular lens to the outside through the insertion part, the push unit being disposed to be unrotatable relative to the main unit but movable in an axial direction of the main unit; and a rotatable member disposed to be rotatable relative to the main unit.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an intraocular lens injector for injecting an intraocular lens into an eye of a patient.  
         [0003]     2. Description of Related Art  
         [0004]     As one of operative treatments for cataract, generally used is a method of removing a crystalline lens from an eye of a patient and then injecting an intraocular lens in place of the crystalline lens. To inject the intraocular lens, the following steps are performed: first making an incision in the eye; fragmenting and aspirating a clouded crystalline lens through the incision by for example an ultrasonic cataract-surgery device (a phaco-emulsification device); and then injecting the intraocular lens into the eye through the incision to implant it in place of the crystalline lens.  
         [0005]     If a large incision is made, it may become a burden on the eye and also cause astigmatism of the eye after the operation. To prevent such disadvantages, an intraocular lens injector is used to inject a foldable intraocular lens into an eye through a smaller incision. In this injector, the foldable intraocular lens held in a housing of the injector is pushed toward the tip of the injector while being folded into a smaller shape. Thereafter, the folded intraocular lens is pushed out of the tip of the injector inserted in the eye through the incision and is spread (unfolded) and placed in the eye.  
         [0006]     When the intraocular lens is to be injected and placed in the eye with the above injector, it is necessary to adjust the direction of spreading (unfolding) the intraocular lens within the eye in order to prevent the intraocular lens from coming into contact with a crystalline lens capsule and others.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     The present invention has been made in view of the above circumstances and has an object to provide an intraocular lens injector capable of adjusting the direction of spreading (unfolding) a folded intraocular lens within an eye while the intraocular lens is being injected to be placed in the eye.  
         [0008]     Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.  
         [0009]     To achieve the purpose of the invention, there is provided an intraocular lens injector for injecting a foldable intraocular lens in an aye, comprising: a substantially cylindrical main unit including a substantially cylindrical insertion part which is insertable through an incision made in the eye, the main unit being adapted to internally hold the intraocular lens and release the intraocular lens to the outside of the injector through the insertion part; a push unit inserted in the main unit to push the intraocular lens to the outside through the insertion part, the push unit being disposed to be unrotatable relative to the main unit but movable in an axial direction of the main unit; and a rotatable member disposed to be rotatable relative to the main unit. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages and principles of the invention.  
         [0011]     In the drawings,  
         [0012]      FIG. 1A  is a schematic plan view of an intraocular lens injector in a preferred embodiment of the present invention;  
         [0013]      FIG. 1B  is a schematic side view of the intraocular lens injector;  
         [0014]      FIG. 2  is a schematic structural view of an intraocular lens;  
         [0015]      FIG. 3A  is a perspective view of a lens holding unit viewed from behind;  
         [0016]      FIG. 3B  is a plan view of the lens holding unit;  
         [0017]      FIG. 4  is a schematic structural view of a main unit and a push unit;  
         [0018]      FIG. 5  is a schematic sectional view of the main unit and the push unit; and  
         [0019]      FIG. 6  is a schematic sectional view of a modification of the main unit. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     A detailed description of a preferred embodiment of the present invention will now be given referring to the accompanying drawings.  FIGS. 1A and 1B  are schematic structural views of an intraocular lens injector  1  in the present embodiment;  FIG. 1A  is a plan view and  FIG. 1B  is a side view.  
         [0021]     The injector  1  includes, in order of insertion into an eye, a substantially cylindrical lens holding unit (a lens cartridge)  10  provided with a substantially cylindrical (tubular) insertion part  11  which is insertable in an incision made in the eye and a setting part  12  in which an intraocular lens (hereinafter, IOL)  40  (see  FIG. 2 ) is to be placed (set), a substantially cylindrical (tubular) main unit  20  in which the lens holding unit  10  is mounted, and a push unit  30  inserted in the main unit  20  and the lens holding unit  10 . This push unit  30  is used to push out the IOL  40  placed in the setting part  12  of the lens holding unit  10  through a front end (a tip end) of the insertion part  11  to the outside. A rotatable member  50  is fitted on a rearward part of the main unit  20  (opposite to the front end) so that the rotatable member  50  is rotatable with respect to the main unit  20  (the details thereof will be mentioned later).  
         [0022]      FIG. 2  is a schematic structural view of the IOL  40 . This IOL  40  includes an optical portion  41  having a predetermined refractive power and a pair of support portions  42  which support the optical portion  41  in an eye. The IOL  40  in the present embodiment is made of a material commonly used for an optical portion of a foldable soft intraocular lens, for example, a monomeric material such as hydroxyethyl methacrylate (HEMA) or a composite material such as acrylic ester and methacrylate ester. The support parts  42  are made of a material commonly used for a support portion of an intraocular lens such as polymethyl methacrylate (PMMA).  
         [0023]      FIGS. 3A and 3B  are schematic structural views of the lens holding unit  10 . Specifically,  FIG. 3A  is a perspective view of the unit  10  viewed from behind (opposite to the tip end),  FIG. 3B  is a plan view. The lens holding unit  10  is entirely made of resin and is a disposable type which is to be thrown away after one use.  
         [0024]     The insertion part  11  of the lens holding unit  10  is formed with a diametrical taper so that its diameter becomes smaller (narrower) toward a tip end  11   a  to be inserted in an incision made in an eye. With this sucture, the folded IOL  40  is further folded into a smaller shape while passing through the hollow of the insertion part  11 , and then the IOL  40  is pushed out (released) through the tip end  11   a  to the outside.  
         [0025]     In the lens holding unit  10 , the setting part  12  is arranged on a side opposite to the tip end  11   a  of the insertion part  11  and adapted to be opened and closed about a hinge  13 . The setting part  12  includes a fixed part  12   a  fixed to the insertion part  11  and a movable part (an openable and closable part)  12   b  connected with the fixed part  12   a  with the hinge  13 . The fixed part  12   a  has a setting surface  14   a  and the movable part  12   b  has a setting surface  14   b . The IOL  40  is placed (set) on the setting surfaces  14   a  and  14   b  while the setting part  12  (i.e., the fixed part  12   a  and the movable part  12   b ) is opened. In this state, the IOL  40  is unfolded.  
         [0026]     Thereafter, when the setting part  12  (i.e., the fixed part  12   a  and the movable part  12   b ) is closed, the shape (in section) of the setting surfaces  14   a  and  14   b  becomes substantially equal to the shape of a semicircular opening  11   b  of the insertion part  11  opening into the setting part  12 . Thus, the IOL  40  placed on the setting surfaces  14   a  and  14   b  is correspondingly folded along the shape of the setting surfaces  14   a  and  14   b . To be more specific, the setting surfaces  14   a  and  14   b  have a curve that allows the IOL  40  to be held in an unfolded state while the setting part  12  is opened and in a folded state when the setting part  12  is closed.  
         [0027]     The fixed part  12   a  and the movable part  12   b  are provided with covers  15   a  and  15   b  respectively. These covers  15   a  and  15   b  are formed to cover the setting surfaces  14   a  and  14   b  above them when the setting part  12  (the fixed part  12   a  and the movable part  12   b ) is closed. The cover  15   b  is provided at an end facing the cover  15   a  with a protrusion  16  extending downward toward the setting surfaces  14   a  and  14   b . This protrusion  16  serves to restrict improper folding of the IOL  40  in a direction other than an opening and closing direction of the setting part  12  corresponding to a folding direction of the IOL  40 .  
         [0028]     A lug  18  formed of a flat plate is provided on the side of the fixed part  12   a . This lug  18  is used as a grip portion to be held by a user with his hand (fingers) to mount the lens holding unit  10  in the main unit  20 .  
         [0029]      FIGS. 4 and 5  are schematic structural views of the main unit  20  and the push unit  30 ;  FIG. 4  is a perspective view of them viewed from behind and  FIG. 5  is a sectional side view of them. The main unit  20  is provided in the forward part with a mounting part  21  in which the lens holding unit  10  is to be mounted. This mounting part  21  is of a substantially half shape (in diametrical section) of the main unit  20  and is formed, in the front, with protrusions  22  in symmetrical relation with respect to a central axis A of the main unit  20 . The protrusions  22  are positioned slightly above the central axis A and have a distance therebetween slightly narrower (shorter) than the inner diameter of the main unit  20 . With this structure, the protrusions  22  serve to guide the setting part  12  in a closing motion when the lens holding unit  10  is mounted in the mounting part  21 . Further, the protrusions  22  engage the lens holding unit  10  to prevent the unit  10  from easily becoming detached from the mounting part  21 . As with the protrusions  22 , right and left edges of the mounting part  21  also serve to guide the setting part  12  in the closing motion.  
         [0030]     The mounting part  21  is formed with a recess  23  in the left back (a right end in  FIG. 1B ). This recess  23  serves to guide the setting part  12  in the closing motion when the lens holding unit  10  is mounted in the mounting part  21 . Further, the recess  23  receives part of a rear edge of the lug  18  in engagement relation to prevent the lens holding unit  10  from easily becoming detached. In the present embodiment, the mounting part  21  is also formed with a recess  23  in the right back. Accordingly, another lens holding unit  10  provided with the fixed part  12   a  and the movable part  12   b  arranged in counterchanged positions (the lug  18  is correspondingly formed on an opposite side) can be used.  
         [0031]     The substantially cylindrical rotatable member  50  having a flared finger rest  50   a  is attached to the rearward part of the main unit  20  which is inserted in the rotatable member  50 . This rotatable member  50  is rotatable about the central axis A with respect to the main unit  20 . The main unit  20  is further provided with a recess  20   a  formed along the outer periphery of the rearward part of the main unit  20 . Correspondingly, the rotatable member  50  is provided, along the inner periphery thereof, with a projection  51  engageable with the recess  20   a  of the main unit  20 . Since the projection  51  of the rotatable member  50  is engaged in the recess  20   a  of the main unit  20 , the rotatable member  50  is prevented (inhibited) from moving in a direction of the central axis A with respect to the main unit  20 . In other words, the recess  20   a  (and the projection  51 ) functions as a stopper to hold the rotatable member  50  so as to be rotatable with respect to the main unit  20  but immovable in the direction of the central axis A.  
         [0032]     The push unit  30  is inserted in the main unit  20  so as to be unrotatable relative to the main unit  20  but movable in the direction of the central axis A. This push unit  30  includes a push portion (rod)  31 , a shaft portion  32 , and a push member (thumb rest)  33 . The push portion  31  is fixedly joined with a front end of the shaft portion  32  which is unrotatable relative to the main unit  20  but movable in the direction of the central axis A. The push member  33  is rotatably attached to a rear end of the shaft portion  32 . Specifically, the rear end of the shaft portion  32  is formed with a screw hole  32   a  in which a screw  34  is tightened through an opening  33   a  centrally formed in the push member  33 . This opening  33   a  has an inner diameter slightly larger than an outer diameter of the screw  34 , thus allowing the push member  33  to rotate about the screw  34 . A stopper  25  is fitted in a rear opening of the main unit  20  so that the push unit  30  (the shaft portion  32 ) is inserted in the stopper  25 , thus preventing the push unit  30  from coming off the main unit  20 .  
         [0033]     An operation of the injector  1  constructed as above will be explained below.  
         [0034]     A user puts (sets) the IOL  40  in the setting part  12  (i.e., on the setting surfaces  14   a  and  14   b ) of the lens holding unit  10  and then holds the lens holding unit  10  by grasping the lug  18  with one hand (normally, his/her thumb and index finger). Thereafter, the user engages the rear end of the lug  18  of the lens holding unit  10  in the recess  23  of the mounting part  21 , and pushes down the setting part  12  into the mounting part  21  so as to press the bottom of the mounting part  12  against the protrusions  22 . Accordingly, the lens holding unit  10  with the fixed part  12   a  and the movable part  12   b  being closed is properly mounted in the mounting part  21 .  
         [0035]     In the closed state of the setting part  12  (the fixed part  12   a  and the movable part  12   b ), the width (distance) of the setting surfaces  14   a  and  14   b  in diametrical section is narrower. At this time, the IOL  40  placed on the setting surfaces  14   a  and  14   b  is subjected to stress and correspondingly folded along the curved setting surfaces  14   a  and  14   b.    
         [0036]     After mounting the lens holding unit  10  in the main unit  20  (the mounting part  21 ), the user performs the following operation to inject the IOL  40  into the eye by manipulation of the injector  1 . To hold the injector  1 , for example, the user may hold the thumb of one hand against the push member  33  while holding the rotatable member  50  between other fingers (normally, the index finger and middle finger) in a manner similar to hold a syringe. At this time, the user should put the fingers on the finger rest  50   a  to easily hold the rotatable member  50 . And the user puts the other hand on the main unit  20  for stabilization.  
         [0037]     When the push member  33  is pushed by the user, the shaft portion  32  and the push portion  31  are moved forward, and the push portion  31  pushes the IOL  40  placed on the setting part  12  into the insertion part  11 . As pushed into the insertion part  11 , the IOL  40  is folded (rolled) along the inner surface of the insertion part  11 . When the push member  33  is further pushed, moving the shaft portion  32  and the push portion  31  forward, the IOL  40  folded up into a smaller shape will be pushed (released) out of the insertion part  11  through the tip end  11   a.    
         [0038]     The IOL  40  will then be spread (unfolded) gradually from a portion pushed (released) out of the insertion part  11  through the tip end  11   a . At this time, the user who holds the rotatable member  50  with one hand may rotate the main unit  20  with the other hand at a desired timing. In association with the rotation of the main unit  20 , the shaft portion  32  and the push portion  31  are together rotated with respect to the push member  33  on which the thumb is pressed. Accordingly, the direction of spreading (unfolding) the IOL  40  is also rotated. This makes it possible for the user to adjust the direction of spreading (unfolding) the IOL  40  within the eye while pushing out the IOL  40 .  
         [0039]     In the present embodiment, the rotatable member  50  is made rotatable with respect to the main unit  20  and the push member  33  is rotatable with respect to the shaft portion  32  (the push portion  31 ). Alternatively, only the rotatable member  50  may be made rotatable. Although the rotatable member  50  is rotatably fitted on the outer periphery of the main unit  20 , the rotatable member  50  only has to be provided at any portion of the injector  1  to be held with user&#39;s fingers and also arranged to be rotatable with respect to the push member  31  (the shaft portion  32 ). For instance, the main unit  20  may be made of separate parts one of which is rotatable to be used as the rotatable member  50 .  
         [0040]     In the present embodiment, furthermore, the rotatable member  50  is rotatably held on the rearward part of the main unit  20 . Alternatively, the rotatable member  50  may be held at one of plural different positions of the main unit  20  along the central axis A. For instance, the rotatable member  50  may be held at either of two positions as shown in  FIG. 6 . In this case, the main unit  20  is formed with two recesses  20   a  spaced apart along the central axis A, which are engageable with the projection  51  of the rotatable member  50 . This structure makes it possible to selectively hold the rotatable member  50  at a desired position so that the user places the rotatable member  50  at a position making it easy to manipulate. In  FIG. 6 , two positions for holding the rotatable member  50  are provided, that is, two recesses  20   a  are formed. However, more than two positions (recesses) may also be provided.  
         [0041]     Furthermore, although the lens holding unit  10  provided with the insertion part  11  and the setting part  12  is removably mounted in the main unit  20 , the main unit (the main body) may be configured to integrally have the insertion part and the setting part.  
         [0042]     While the presently preferred embodiment of the present invention has been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims.