Abstract:
A microsurgical forceps has a pair of opposed jaws which are configured to create a window through which a user can view tissue underlying the jaws. The window and the tapered lateral profiles of the jaws increase the field of view available to a user.

Description:
[0001]    This application claims priority from U.S. Patent Application Ser. No. 60/986,491, filed Nov. 8, 2007, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to surgical instruments designed for use in eye surgery and, more particularly, to a forceps used to remove fibrous material from the eye and to lift the tissue to be removed in the manner of a pick or spatula. 
       BACKGROUND OF THE INVENTION 
       [0003]    Certain ophthalmological surgical procedures require the peeling or delamination of the retinal ILM. A description of the various surgical techniques requiring delamination may be found in the second edition of  Vitreous Microsurgery  by Steve Charles, Williams and Wilkins, 1987, particularly at pages 120-121, 222, 163 and 164. Charles describes the use of a scissors to effect cuts in the ILM, reducing it to small enough pieces to be removed from the eye. 
         [0004]    Surgeons now use blunt dissection techniques, employing instruments such as the VRTIS™ ILM spatula sold by ASICO, LLC, of Westmont Ill. as its Model Nos. AE-2917 and AE-2921. Such a spatula includes a handle to which a shaft is mounted with the shaft terminating in a shaped tip having no sharp edges. The tip is typically contoured and slightly curved to enable manipulation of the spatula along the rear portion of the eye to perform a delamination of the ILM. The blade is shaped for delamination of the ILM and can be manipulated to bring it into a preferred position for delaminating other portions of the ILM. 
         [0005]    After removal of the ILM fibrous tissue remaining behind must also be removed. Use of a forceps such as the VRTIS 23 gauge fine and gripping forceps marketed by ASICO, LLC of Westmont, Ill. as its Model AE-4912 can carry out the fiber removal procedure. 
         [0006]    The use of picks and forceps to remove portions of the ILM are described in U.S. Pat. No. 6,024,719 (Morris); U.S. Pat. No. 6,210,357 (Morris); and U.S. Patent Application Publication 2006/0116703 (Glaser). 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0007]    An improved gripping forceps particularly useful in ILM delamination has a jaw geometry which increases the surgeon&#39;s field of vision. The jaws are shaped to be used in much the same manner as a pick is used, that is, to engage the periphery of the ILM and to lift it, beginning the delamination and removal process. 
         [0008]    While the following describes a preferred embodiment or embodiments of the present invention, it is to be understood that this description is made by way of example only and is not intended to limit the scope of the present invention. It is expected that alterations and further modifications, as well as other and further applications of the principles of the present invention will occur to others skilled in the art to which the invention relates and, while differing from the foregoing, remain within the spirit and scope of the invention as herein described and claimed. Where means-plus-function clauses are used in the claims such language is intended to cover the structures described herein as performing the recited functions and not only structural equivalents but equivalent structures as well. For the purposes of the present disclosure, two structures that perform the same function within an environment described above may be equivalent structures. 
     
    
     
       DETAILED DESCRIPTION OF THE INVENTION 
         [0009]    These and other aspects of the present invention will best be understood by reference to the accompanying drawings wherein: 
           [0010]      FIG. 1  is a perspective view of a prior art gripping forceps; 
           [0011]      FIG. 2  is a partial perspective view of a gripping forceps in the closed position with jaws embodying principles of the present invention; 
           [0012]      FIG. 3  is an enlarged detail of a portion of the jaws of  FIG. 2 ; 
           [0013]      FIG. 4  is a partial perspective view of the forceps of  FIG. 2  with the jaws in a partially opened position; 
           [0014]      FIG. 5  is an enlarged detail of the jaws of the forceps shown in  FIG. 4 ; 
           [0015]      FIG. 6  is a partial perspective view showing the jaws completely open; 
           [0016]      FIG. 7  is a partial lateral perspective view of the forceps of  FIG. 2  showing the jaws in a closed position; and 
           [0017]      FIG. 8  is an enlarged detail of a portion of the jaws shown in  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       [0018]    Referring now to  FIG. 1 , the numeral  10  identifies a prior art gripping forceps having a body  12  to which a pair of operating handles  14 ,  16  are hingedly mounted. Body  12  terminates in a mount  18  within which a hollow tube  20  is slidably held. A pair of spring steel forceps elements, each terminating in a jaw is disposed within tube  20  and are secured within body  12  so that the elements do not move. The jaws extend from tube  20  and, when tube  20  is withdrawn, are biased to be urged apart from one another. In the example shown, which represents a commonly available and known prior art body and handle assembly, when handles  14 ,  16  are compressed toward body  12 , tube  20  is advanced, engaging ramps formed on the exterior surfaces of the jaws and forcing the forceps elements towards each other to bring the jaws into contact with one another. For purposes of identification in  FIG. 1 , the numeral  22  indicates generally the jaws as they protrude from tube  20 . For purposes of further description, it will be assumed that gripping forceps  10  has had its original forceps elements replaced by forceps elements which terminate in jaws that embody the present invention 
         [0019]    Referring now to  FIG. 2 , a detail of a forceps is shown with each forceps element having a jaw that embodies certain principles of the present invention. As can be seen in  FIG. 2 , a jaw assembly  24  is shown in a first or closed position. Jaw assembly  24  comprises jaw  26  and jaw  28 . For purposes of description, jaw  26  will be described as the left jaw while jaw  28  will be described as the right jaw. It should be understood that the left and right jaws  26 ,  28  are formed at the distal end of forceps elements such as those described hereinabove with the remainder of the forceps elements disposed within tube  20 . 
         [0020]    Referring now to  FIG. 3 , left jaw  26  is shown having an outer surface  30  and an inner surface  32 . Outer surface  30  has a ramp  34  formed thereon which extends outwardly from surface  30 . A first segment  36  of left jaw  26  extends in a generally longitudinal direction and then terminates in a jaw tip  38  which is formed generally perpendicular to segment  36 . Jaw tip  38  terminates at jaw end  40 . 
         [0021]    In the example shown, right jaw  28  is a mirror image of left jaw  26 , having an outer surface  42 , an inner surface  44 , a ramp  46 , a first longitudinally extending segment  48  and a jaw tip  50  terminating at a jaw end  52 . 
         [0022]    Inner surface  32  has a first segment  32   a  which extends in a generally longitudinally direction, and a second segment  32   b  which is arcuate in shape and which curves toward outer surface  30  and which terminates at the point at which jaw tip  38  and  48  are in contact with each other. A similar configuration is seen with segments  42   a  and  42   b  of right inner jaw surface  42 . The effect of this shaping is to create a “window” or “bight” 54  when jaws  26 ,  28  are fully closed and jaw ends  40 ,  52  are in contact with one another, through which the surgeon may observe the operating field, an advantage which aids in the location of tissue to be removed and the manipulation of the forceps to grasp this tissue. 
         [0023]    In the present example, each jaw tip  38 ,  50  is approximately 0.40 mm in length and jaw assembly  24 , when closed, is approximately 0.60 mm wide when measured from ramp  34  to ramp  46 , and is 0.35 mm wide when measured adjacent to said ramps, tapering down to a minimum width of about 0.30 mm across jaw tips  38 ,  50 . Each jaw tip  38 ,  50  is about 0.15 mm in length, about 0.16 mm in width and about 0.18 mm in thickness. 
         [0024]    Referring now to  FIG. 4 , left and right jaws  26 ,  28  are shown in a partially opened position. This results when handle  14 ,  16  are allowed to move apart from one another which, in turn, allows tube  20  to move longitudinally toward body  12 , thereby disengaging ramps  26 ,  28  and allowing the natural tendency of the forceps elements to separate. 
         [0025]    An enlarged view of this is shown schematically in  FIG. 5  with the withdrawal of tube  20  shown in a somewhat exaggerated illustration to show left forceps element  56  and right forceps element  58 . Surfaces  32   a,    32   b,    42   a  and  42   b  allow an even greater field of vision when jaws  26 ,  28  are partially opened as well. 
         [0026]    Referring now to  FIG. 6 , handles  14 ,  16  are fully extended and tube  20  is retracted sufficiently to allow left and right jaws  26 ,  28  to reach their maximum opening. In this position, it should be appreciated that jaw tips  38  and  50  are sufficiently separated to allow them to be manipulated to “hook” one said jaw tip under the outer margin of the ILM, thus providing the forceps with not only a gripping capability but the ability to function as a pick or spatula. When the jaw tips  38 ,  50  are so used, it is not necessary to introduce a second instrument, namely a pick or spatula, to begin the separation of the ILM and, thereafter, to reinsert the forceps to grip that portion of the ILM and remove it. 
         [0027]      FIG. 7  shows a lateral view of forceps  10  with left and right jaws  26 ,  28  in the fully closed position. It can be seen that the lower surface  56  of right jaw  28  has a first segment  56   a  which extends generally longitudinally, a second segment  56   b  which curves upward and away from segment  56   a,  and a third segment  56   c  at which the curvature  56   b  is carried slightly downward. Left jaw  26  is a mirror image of right jaw  28  and has a similarly contoured lower surface. The effect of this configuration is to provide a narrowed profile which provides a larger field of vision for the surgeon. 
         [0028]    As seen in  FIG. 8 , in a preferred embodiment, jaw  28  is about 0.23 mm across at portion  62  and is about 0.18 mm across jaw tip  48  at segment  64 .