Abstract:
A device transfers donor endothelial cells to the cornea of a recipient without injuring the cells or the cornea during the transfer process. The device transfers living endothelial cells from a donor to a recipient with minimal or no trauma. The device includes a handle, an irrigation tube lengthwise within the handle, a button upon the handle concentric with the irrigation tube, a tapered nose opposite the button, a forward tube extending outwardly from the nose, and a platform joined to the irrigation tube. The forward tube has an elliptical cross section and two beveled features. The platform has two wings that curl gently around donor tissue upon retracting the platform into the forward tube. The handle has a groove for a stem of a knob that surgeon presses and pulls to move the platform.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This non-provisional application is a continuation in part of the non-provisional application for patent having the U.S. Ser. No. 12/027,822 filed on Feb. 7, 2008 now abandoned which claims priority to the expired provisional application having the U.S. Ser. No. 60/889,236 filed on Feb. 9, 2007 and both are owned by the same assignee, and both disclosures are incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The corneal endothelial tissue inserter relates to medical devices that work with eye tissue and more specifically to a device that retracts an extremely thin layer of donor endothelial eye tissue and then places this tissue within the eye of a recipient. 
     People have eyes to see. An eye has various parts that receive and focus light upon a retina that converts the light into electrical signals transmitted to a is person&#39;s brain for interpretation. In the vicinity of a person, light encounters a cornea as the first part of the eye. The cornea, generally transparent, admits light further into the eye. The cornea has its own constituent parts where the endothelium is the extremely thin, innermost layer of the cornea. Endothelial cells serve an essential purpose to keep the cornea clear, that is, transparent. Normally, fluid, vitreous humor, leaks slowly from inside the eye into the middle corneal layer, or stroma. The endothelium&#39;s primary task involves pumping this excess fluid, now aqueous humor, out of the stroma. Without this pumping action, the stroma swells with water, becomes hazy and ultimately opaque leading progressively to blindness. A healthy eye has a perfect balance between the fluid moving into the cornea and fluid being pumped out of the cornea. Upon destruction of endothelium cells by disease or trauma, those cells become lost forever. With too many endothelial cells destroyed, corneal edema and blindness ensue requiring the only therapy, corneal transplantation. 
     Over the years, various physicians and instrument manufacturers have attempted to collect, to maintain, to remove, and to transplant endothelial cells from a donor eye to a recipient. Physicians have developed the technique of Descemet&#39;s stripping with endothelial keratoplasty (DSEK) to repair afflicted corneas. Few, if any instruments and techniques allow for ready transplant of endothelial cells. A precursor technique incises a donor cornea upwardly of five mm and retrieves endothelial cells using an ophthalmic forceps. Upon removing the cells from the donor and then inserting the cells through a five mm opening in a recipient&#39;s eye, the forceps far too often crush and damage the endothelial cells and select adjacent tissue in the recipient&#39;s eye. 
     DESCRIPTION OF THE PRIOR ART 
     However, instrument makers and physicians continue to seek better ways is of transplanting endothelial cells. Various instrument patents have appeared over the years. The U.S. Pat. No. 5,098,439 to Hill et al. describes an apparatus that inserts lenses intraocular. The apparatus has a foldable paddle upon a mechanism within a tube. The paddle carries a foldable lens through an incision in an eye. However, the tube 214 has a generally constant outer diameter, a round shape, and a square end as in FIG. 6 of Hill. 
     The U.S. Pat. No. 5,876,440 to Feingold illustrates a method to use a device implanting an intraocular lens in an eye. The device utilizes a knob 18 upon a threaded cylinder within a threaded handle. Turning of the knob advance the threaded cylinder into the handle thus moving a cartridge forwardly so a tip 20 may insert a lens. However, the tip does not enwrap tissue and the tip surfaces taper inwardly, opposite of the present invention. 
     And Van Gent has U.S. Pat. No. 4,955,889 for an eye lens insertion apparatus. This apparatus utilizes a heating system that extends into a cradle. The cradle has a shape memory material that unfolds upon reaching a select temperature. This apparatus though lacks an irrigation system and folding of the cradle without an overlap. 
     The present invention overcomes the disadvantages of the prior art and provides a paddle that rolls endothelial tissue upon it without folding, produces 30% less tissue damage than existing techniques, provides proper orientation of the tissue in the recipient&#39;s eye, prevents physicians from inserting the tip too far into the eye, and treats adult, pediatric, and Asiatic eye types. The instrument of the present invention allows for the transfer of living endothelial cells with minimal or no trauma. 
     SUMMARY OF THE INVENTION 
     Generally, the corneal endothelial tissue inserter has a reusable, hollow rigid tube, or barrel, that has a disposable tissue holder, or transfer chamber, at its distal end. This holder is generally a soft, plastic platform-paddle connected to the barrel by a thin rod, or tube, advanced from or retracted into the barrel by turning a knob at the proximal end. The tube allows for irrigation of the paddle and tissue thereon during usage of the invention. The knob operates upon a threaded system and advances or retracts the paddle at multiple positions while a surgeon holds the instrument. The platform also advances or retracts by sliding a flow regulator ring forward or backward. The flow regulator ring connects to the rod with a lumen. The lumen connects to the disposable platform that houses and protects the donated endothelial tissue during the transfer process. 
     Turning the knob retracts the paddle into the barrel and causes the soft plastic paddle to conform to the walls of the barrel, thus folding the paddle into a cylinder slightly smaller in diameter than the internal diameter of the distal end of the tapered barrel opening. This operation gently rolls the corneal endothelial tissue seated on the inside of the paddle with no acute folds. Depending on the diameter of the paddle, a surgeon may roll the tissue using the bi-fold, that is 60/40, or tri-fold, or taco, techniques. Because the tissue transfers from the donor eye without forceps and no forcing of the tissue through a small incision occurs, these rolling techniques have relatively safe use. The paddle rolls the tissue within the elliptical tube and protects the vital cells during the transfer process through a small incision. The paddle, made of a flexible soft plastic, can have different diameters that ease transplantation through different size incisions. Rolling the tissue allows for a transfer device that use a smaller paddle and thus smaller incisions in the donor and recipient eyes. The soft material of the paddle surrounds the tissue and protects it during the transfer process, that is, no crushing and no squeezing through an incision as in the prior art forceps transfer. After retracting the paddle that houses and protects the tissue, the surgeon inserts the distal, tapered end of the barrel into the incision in the recipient&#39;s eye. The physician receives a tactile indication to halt the insertion from a tapered stop that abuts the surface of the eye. Rotating the knob to extend the rod causes the paddle to unroll thereby allowing the tissue to release and naturally resume its shape. Irrigation, controlled with a flow regulator, upon demand supplies lubrication if the tissue sticks to the paddle or resists unrolling or if the anterior chamber requires support during transfer. 
     Further, different size platforms may see use to house the tissue during the tissue transfer process. Other devices for retracting the platform within the protective barrel remain available such as threads or push rod. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and that the present contribution to the art may be better appreciated. Additional features of the invention will be described hereinafter and which will form the subject matter of the claims attached. 
     Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of the presently preferred, but nonetheless illustrative, embodiment of the present invention when taken in conjunction with the accompanying drawings. Before explaining the current embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and is carried out in various ways. Also, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     One object of the corneal endothelial tissue inserter is to provide an inserter that can readily collect, transport, and deliver endothelial tissue without folding. 
     Another object of the corneal endothelial tissue inserter is to provide such an inserter that produces less cell damage than existing devices. 
     Another object of the corneal endothelial tissue inserter is to provide such an inserter that readily provides complete control of the device by the surgeon before, during, and after usage. 
     Another object of the corneal endothelial tissue inserter is to provide such an inserter that has a tip arrangement that limits further insertion of the tip by the surgeon. 
     Another object of the corneal endothelial tissue inserter is to provide such an inserter that has a tip arrangement that avoids inadvertent adherence to eye tissue during usage. 
     Another object of the corneal endothelial tissue inserter is to provide such an inserter that has a low cost of manufacturing so the surgeons and hospitals can readily purchase the inserter through existing medical supply outlets. 
     These together with other objects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In referring to the drawings, 
         FIG. 1  illustrates a side view of an instrument, in accordance with an embodiment of the present invention; 
         FIG. 2  describes a top view of an embodiment of the instrument; 
         FIG. 3  shows a partial cross section of the opposite of distal end of the instrument; 
         FIG. 4  shows the partial cross section of  FIG. 3  where the paddle is extended outwardly from the instrument; 
         FIG. 5   a  illustrates a detailed view of a paddle having short outward wings; 
         FIG. 5   b  illustrates a detailed view of a paddle having long outward wings; 
         FIG. 6   a  describes an end view of a paddle retracted with a left wing overlapping a right wing; 
         FIG. 6   b  describes an end view of a paddle retracted but with a right wing overlapping a left wing; 
         FIG. 6   c  describes an end view of a paddle retracted with a right wing flexing above a left wing; 
         FIG. 7  shows a top view of a second alternate embodiment of the instrument; 
         FIG. 8  shows a top view of the preferred embodiment of the instrument when presenting tissue; 
         FIG. 8   a  describes a rear view of the preferred embodiment of the instrument; 
         FIG. 9  illustrates a side view of the instrument; 
         FIG. 9   a  shows a front view of the instrument; 
         FIG. 9   b  shows a front view of the instrument; 
         FIG. 10  provides a bottom view of the instrument; 
         FIG. 11  shows a top view of the preferred embodiment of the instrument but with the platform retracted; 
         FIG. 12  provides an end view of the instrument with a retracted platform; 
         FIG. 13  describes an exploded view of the instrument; and, 
         FIG. 14  shows a detailed view of the tube of the instrument. 
     
    
    
     The same reference numerals refer to the same parts throughout the various figures. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention overcomes the prior art limitations by providing an instrument that retrieves and delivers endothelial tissue without damage to the tissue and recipient eye. Referring now to  FIG. 1 , it shows an alternate embodiment in a side view of an instrument  10 . This instrument has a hollow rigid tube, like a barrel or handle  12  with a disposable tissue holder or transfer chamber  14  at a distal end of the instrument. The holder  14 , or platform, advances forward or retracts rearward into the barrel  12  by pushing or pulling a tab  16  at a proximal end of the barrel  12 . Referring to  FIG. 2 , it shows an alternate embodiment in a top view of the instrument  10 . The instrument also includes a flow regulator ring  20  that also moves forward or rearward to advance or retract the tissue holder or platform  14 . Next,  FIG. 3  shows a side sectional view of the alternate embodiment of instrument  10  with the holder  14  retracted completely into barrel  12 . 
     Turning to  FIG. 4 , the alternate embodiment of the instrument appears in a side view with the holder  14  advanced fully forward of the barrel  12 . Referring to  FIGS. 5   a  and  5   b , alternate embodiments shown have a tissue holder  14  that is retracts and advances and has tissue holder flaps  22  that attain a platform open position  24  and platform closed position  26 . The tissue holder flaps  22  conform to the walls of the barrel  12  and form a cylindrical shape to insert easily into the barrel  12 . Then referring to  FIGS. 6   a ,  6   b ,  6   c , the instrument appears in an end view with the platform forward. More particularly,  FIG. 6   a  shows the initial folding of the flaps  22  around corneal endothelial tissue  30  into a trifold arrangement as at  32 .  FIG. 6   b  provides an illustration of folding the flaps  22  around the corneal endothelial tissue  30  into a reverse trifold arrangement as at  34 . Then  FIG. 6   c  describes folding of the flaps  22  around the corneal endothelial tissue  30  in a bifold arrangement as at  36 . 
     Referring to  FIG. 7 , an alternate embodiment of the present invention appears in a top view of the instrument  10 . This alternate embodiment has two irrigation channels  40  that provide fluids to the platform  14 , if the tissue  30  sticks to the platform  14  or the tissue  30  resists unfolding once the platform  14  is open. The fluid from the irrigation channels also maintains the anterior chamber of the eye during the transfer of tissue  30  into the eye. 
     Then  FIG. 8  shows the preferred embodiment of the instrument  10  from the top as seen by a surgeon during usage. The instrument has a length, a width perpendicular to the length, and a longitudinal axis generally centered upon the length. The instrument has its platform  14  show fully extended outwardly. The platform has a blunted spade like shape with a leading edge  50  substantially perpendicular to the longitudinal axis. The leading edge has a generally convex shape with a radius of curvature greater than the width of the platform. The leading edge has two ends that each begin a wing  51 . Each wing extends outwardly from the longitudinal axis and rearwardly from the leading edge  50 . Each wing widens rearwardly from the leading edge until each wing reaches an inflection point  52  which denotes the maximum width of the platform. Rearwardly is of the inflection points, the platform sharply narrows in width along its trailing edges  52   a . The platform joins to an irrigation tube  53  at the forward end  53   a  of the irrigation tube. 
     The irrigation tube is hollow, slender, and elongated with a length slightly less than the entire length of the instrument. Opposite the forward end  53   a , the irrigation tube has its rear end  53   b . As shown in this figure, the forward end  53   a  extends slightly outwardly from the remainder of the instrument while the rear end  53   b  remains interiorly from the remainder of the instrument. 
     Rearward of the platform  14  and the forward end  53   a , the instrument has its forward tube  54  of lesser width than the leading edge  50  of the platform. The forward tube begins at a narrow width, as at  54   a , that widens away from the platform to its maximum width, as at  54   b . The forward tube is generally hollow and has an elliptical cross section as later shown in  FIG. 9   a . The elliptical cross section extends from the narrow width, as at  54   a , of the tube rearward to the maximum width, as at  54   b . Rearward of the maximum width, as at  54   b , the forward tube has an increase in thickness around its perimeter for the remainder of its length away from the platform. The increase in thickness begins along a bevel from the side of the instrument. In this figure, the bevel appears as a partial arc, as at  54   d , having a radius of curvature exceeding the widest width of the forward tube. 
     Opposite the narrow width, as at  54   a , of the forward tube, the instrument continues with a nose  55  joined to a far end  54   c  of the forward tube. The nose begins with a greater diameter than the far end  54   c  that expands to a maximum diameter for short length as at  55   b . The nose serves as the truncated apex of a round cone while the nose has a hollow frusto-conical shape beginning just behind the far end and expanding in diameter to its maximum at  55   b . The nose has a length from smaller to larger diameter, as at  55   a . Rearward, that is, away is from the platform, the nose has a short length, as at  55   c , at its maximum diameter. Then rearward from the nose, the instrument has its handle  12  at a diameter slightly larger than the maximum diameter of the nose. 
     Like the forward tube and the nose, the handle remains hollow and coaxial with the nose and the forward tube. Somewhat near the platform, the handle has its proximal grip  12   a  with a generally slight concave shape suitable for griping by the thumb and forefinger of a surgeon. The proximal grip extends around the entire perimeter of the handle to allow a surgeon to rotate the instrument while maintaining a grasp of it. The proximate grip has a radius of curvature generally greater than the length of the instrument. Rearwardly from the proximal grip, the handle has a section of ribbing  56  formed of a plurality of ribs,  56   a . Each rib has a maximum diameter that of the maximal diameter of the proximal grip, that is, the diameter of the handle. Between adjacent ribs, a gap has a slightly lesser diameter than the ribs that provides a grasping surface of the palm of the surgeon&#39;s hand. The ribbing extends for at least one quarter of the overall length of the instrument. Rearwardly from the ribbing, the handle has its distal grip  12   b . The distal grip also has a generally slight concave shape suitable for griping by the palm and little finger of a surgeon. The distal grip also extends around the entire perimeter of the handle to allow a surgeon to rotate the instrument while maintaining a grasp of it. The distal grip has a length along the instrument generally greater than the proximate grip. The distal grip has a radius of curvature generally greater than the length of the instrument. The distal grip begins and ends at the diameter of the instrument. And rearwardly from the distal grip, that is, distally upon the instrument, the handle has its button  57  generally a short cylinder, round in shape, with a rounded edge. The button rotates about an axis coaxial with the longitudinal axis of the instrument. The button has a socket  57   a  for receiving an irrigation supply line, not shown, that is connects to the irrigation tube  53 . 
     The irrigation tube, shown in phantom, extends for the length of the instrument  1 . The irrigation tube has its forward end  53   a  that connects with the platform  14  proximate the trailing edges  52   a . The tube then passes through the forward tube  54 , the nose  55 , the handle  12 , and has its rear end  53   b  entering the button socket  57   a . Proximate the button socket, the handle has a reinforcing cone  12   c  centered upon the rear end  53   b . The tube extends outwardly from the apex of the cone  12   c  for a sufficient distance suitable for the tube to connect with a supply line. The reinforcing cone has a maximum diameter inwardly from the button and an opening through the height of the cone for the irrigation tube. The opening has a diameter similar to that of the irrigation tube for its tight fit into the opening. 
     As described, the irrigation tube extends lengthwise through the handle  12 . For passage of the irrigation tube, the handle has a chamber  12   d  having a diameter greater than that of the irrigation tube and less than the diameter of the button. The chamber&#39;s diameter is also less than the narrowest diameter of either the proximal grip or the distal grip. The chamber extends from just inside of the button  57  forwardly through the distal grip, ribbing, and proximal grip. The chamber is generally coaxial with the longitudinal axis of the instrument. Where the straight portion  55   e  of the nose adjoins the handle as shown, the chamber steps inwardly in diameter, as at  12   e , forming an inner diameter through the forward tube in within the nose. Forwardly from the step, the chamber has a lesser diameter than when in the handle. The lesser diameter extends for the length of the nose. The forward tube  53  then fits into the lesser diameter of the chamber proximate the apex of the nose  55 . 
     Viewing the button  57 ,  FIG. 8   a  shows the instrument  1  from the rear, or as is in the surgeon&#39;s hand proximate the little finger during usage. The button is generally round in shape having a diameter similar to that of the handle  12 . Generally centered upon the button, the socket  57   a  is recessed inwardly but not completely through the thickness of the button. The socket has a diameter that receives an irrigation supply line. The socket diameter generally exceeds that of the irrigation tube. Proximate the interior of the socket, the rear end  53   b  of the irrigation tube occupies the center of the socket. The rear end  53   b  enters the socket partially through its depth but does not exit the socket, or extend beyond the button. Outwardly from the rear end and inwardly from the socket, the reinforcing cone  12   c  appears in an end view of its apex. 
     Turning the invention,  FIG. 9  illustrates the instrument from the side in an orientation for use by a surgeon. This view begins with the platform  14  extended from the handle  12  to the left. The platform has its leading edge  50  to the left and then its wing  51  here shown slightly curved upwardly to its inflection point  52 . Rearward of the inflection point, the platform shows its trailing edge  52   a . The trailing edges merge as the platform  14  joins to the forward end  53   a  of the irrigation tube. The platform has a generally flat orientation as it joins the forward end  53   a.    
     Rearward from the platform, the forward tube  54  has a bevel  58  angled away from the platform and towards the handle. The bevel extends across the narrow width  54   a  of the forward tube. The bevel occupies a plane at less than ninety degrees from the longitudinal axis of the instrument. The bevel  58  and curved arc of the narrow width  54   a  cooperate to guide the instrument to a proper orientation upon the eyeball of a recipient of endothelial tissue. The narrow width of the forward tube fits into a precise incision in the recipient&#39;s eyeball. Away from the bevel, the forward tube grows slightly in its height. Where the forward tube has its maximum width,  54   b , it also has its maximum height as at  54   e . At its maximum height, the forward tube steps outwardly in thickness as previously described along a second bevel  59 . The second bevel is generally parallel to the first bevel  58  though extending slightly higher and slightly lower as shown. The second bevel with slightly larger width and height than the first bevel provides a tactile warning to the surgeon that the instrument has inserted into the recipient&#39;s eye for the maximum distance. 
     In the preferred embodiment, the forward tube extends away from the second bevel at a constant height and width. The forward tube then joins the nose as previously described. In an alternate embodiment, the forward tube has a slight increase in height in this view at its neck  60  proximate the nose. 
     Within the forward tube, the irrigation tube  53  extends away from the platform  14 . Proximate the platform, the irrigation tube has a closed, rounded forward end. Away from the forward end, which is towards the grip of the handle, the irrigation tube has an angled cut to its opening. This angled cut provides for the exit of irrigation fluid and for a connection to the trailing end of the platform. The connection is somewhat hemispherical when viewed on end as in  FIG. 9   b . Rearward from the connection the irrigation tube returns to its outside diameter for the remainder of its length. Perpendicular to the irrigation tube, a stem  61  extends outwardly from the irrigation tube and also opposite from the curl of the platform  14 . The stem extends outwardly from the proximal grip  12  and slightly more than the maximum diameter of the nose as at  55   c . The stem has a bar  62  or tab upon its end opposite the irrigation tube. The stem also fits into a slider  63 . The slider is preferably a round cylinder within the chamber  12   d  that has a diameter slightly less than the diameter of the channel. The slider also has the irrigation tube passing through it lengthwise. The stem has a position upon the slider so that when the stem is advance forward towards the nose, the slider abuts the end of the chamber as at  55   e  preventing further inadvertent insertion is of the platform into a recipient&#39;s eye. The slider reinforces the connection between the stem and the tube so that the stem does not bend the tube or otherwise jam the instrument. The slider itself has a length less than the length of the proximal grip of the handle. By pushing and pulling the bar, a surgeon advances and retracts the platform within a defined distance. 
     Viewing the front of the instrument  1 ,  FIG. 9   a  shows the platform fully extended outwardly from the plane of the figure. The platform  14  is primarily flat in its center between the wings  51  behind the leading edge  50 . The wings curve upwardly, that is, away from the tab  62 . Opposite the leading edge  50  the platform joins to the forward end  53  of the irrigation tube. At the forward end, the tube has a generally hemispherical closure providing a solid end that does not allow straight passage of irrigation fluid upon the platform. Away from the forward end, the irrigation tube has an angled cut to its opening and the irrigation fluid exits the irrigation tube from there for a more smooth flow of the irrigation fluid onto the platform. 
     Similar to  FIG. 9   a ,  FIG. 9   b  shows the platform fully retracted into the forward tube. The forward tube has its elliptical shape of its narrow end  54   a . When a surgeon retracts the tab upon the stem and pulls the platform rearwardly, the trailing edges  52   a  gently curl the wings  51  upwardly and inwardly but not so far that the trailing edges contact each other. The platform  14  along with the tube  53  retract into the handle  12  as the slider  63  retracts under the control of the surgeon. 
     Then  FIG. 10  provides a bottom view of the instrument, that is, the area of the invention gripped by the surgeon during usage. The instrument  1  has its platform  14  here shown fully extended. Behind the leading edge  50 , the wings  51  have a slight curl into the plane of the figure. The trailing edges  52  then contact the narrow width, as at  54   a , of the forward tube  54 . The forward tube is then expands outwardly and rearwardly to its maximum width as at  54   b . The curve,  54   c , denoting the maximum width is generally opposite that portion shown in  FIG. 8 . The narrow width and maximum width show the forward tube as having an outwardly expanding cross section. At the curve of maximum width, the forward tube has a stepped increase in height and width, as at  54   c , and extends rearwardly at a constant width and height. With the irrigation tube inside of it, the forward tube joins to the nose  55  that expands its conical shape to its maximum diameter as at  55   b . The nose then has its small portion of constant diameter  55   e  that matches with the proximal grip  12   a  of the handle  12 . Generally centered and extending parallel to the longitudinal axis of the handle, the proximal grip includes the slider  63  passing within the chamber  12   d . As before the slider has a diameter and length for a snug but moveable fit within the chamber. Outwardly from the slider, the proximal grip includes a slot  12   e . The slot has a narrower width than the diameter of the slider  63 . The slot defines the forward and rearward limits for the stem beneath the bar  62 . The forward limit in cooperation with the stem advances the platform to its fully extended position as shown. Opposite the panel, the irrigation tube  53   b  extends slightly outwardly from the vicinity of the distal grip. 
     Similar to  FIG. 10 ,  FIG. 11  shows the instrument from the bottom but with the platform  14  fully retracted. The platform curls its wings  51  slightly away from the plane of the figure and within the forward end  53   a  of the forward tube. The tab  62  retracts the stem and the slider  63  rearwardly. As the slider moves, the tube  53  also moves rearwardly. In doing so, the rear end  53   b  of the irrigation tube moves outwardly from the reinforcing cone  12 , further into the button  57  but not through the button. During movement of the rear end  53   b , any supply line remains connected. 
     Then  FIG. 12  describes a front view of the invention with the platform  14  is retracted into the forward tube  54 . The forward tube has its narrow width  54   a  surrounding the platform in this view. The forward tube has a generally elliptical shape. Being elliptical, the cross section of the forward tube has a major axis and a perpendicular minor axis. The major axis is generally perpendicular to the stem while the minor axis is generally parallel to the stem. Rearwardly from the narrow width  54   a , the forward tube expands slightly outwardly along the major and minor axes to the bevel  54   e . Rearwardly from the bevel, the forward tube has its increase in thickness from its maximum width  54   b  to its junction with the nose  55  having its length, as at  55   a , and its maximum diameter as at  55   b.    
       FIG. 13  then illustrates an exploded view of the invention beginning with the platform  14 . The platform has a spade like shape with its leading edge  50 , wings  51 , and trailing edges  52 . The trailing edges merges into a tang  14   a  of narrower width than the leading edge. The tang connects with the forward end  53   a  of the irrigation tube  53 . The irrigation tube is generally hollow, elongated, and slender as previously described. A certain distance inward from the forward end, the stem  61  joins perpendicular to the irrigation tube. The stem and the tang join to the same side of the irrigation tube, that is, the wings of the platform curl opposite the stem. The stem fits into the slider  63  that itself fits into the chamber  12   d  of the handle  12 . Outwardly of the slider and the instrument  1 , a tab  62  connects to the end of the stem opposite the irrigation tube. Opposite the forward end  53   a , the irrigation tube has its rear end  53   b , generally open for connection to a supply line. The handle  12  begins with the narrow width  54   a  of the forward tube  54 . Then the forward tube expands in height and width to its maximum at  54   b . The forward tube then steps outwardly its thickness until it joins the nose  55 . The nose has its frustoconical shape that expands outwardly to the maximum diameter of the handle, as at  55   b . The handle  12  then has its proximal grip  12   a  with the groove  12   f  for the stem. Behind the proximal grip, the is handle has its ribbing  56  for a substantial portion of its length and then the distal grip  12   b . The chamber  12   d  passes through the proximal grip, the ribbing, and the distal grip. Opposite the nose, the handle has the button  57  that rotates upon the handle and has its socket to admit a supply line. 
     And,  FIG. 14  shows the forward tube in more detailed views.  FIG. 14   a  shows the tube  54  from the top as a surgeon would view it. The forward tube has its narrow width  54   a  to the left upon the beveled end as at  58 . The forward tube expands rearwardly to its maximum width as at  54   b . At the maximum width, the second bevel  54   d  denotes the step in thickness for the remainder of the tube. The beveled end and second bevel have arcs of a concave appearance denoting the direction of the bevel, here in a plane rotated towards the handle but opposite the tab. Rearward of the second bevel, the forward tube has its stepped thickness as shown. Rotating the tube ninety degrees upwardly in the figure to  FIG. 14   b , the forward tube has its beveled end  58  shown angled into the tube. The beveled end begins at the narrow width  54   a  and expands outwardly to the maximum width  54   b . The second bevel has its side shown here as in  54   e . The second bevel extends around the perimeter of the forward tube. Rearward from the second bevel, the forward tube has its stepped thickness as at  59 . Rotating the tube another ninety degrees,  180  degrees total,  FIG. 14   c  shows the bottom view of the forward tube opposite that of  FIG. 14   a . The forward tube has its narrow width  54   a  at its beveled end  58 . Inwardly from the beveled end, the forward tube has its second bevel  54   d . The beveled end and the second bevel have convex arcuate forms denoting the plane of the bevels as previously described. Away from the second bevel, the forward tube has its stepped thickness  59 . And rotating the tube a last ninety degrees,  270  degrees in total,  FIG. 14   d  shows the forward tube generally opposite that of  FIG. 14   b . The narrow width  54   a  of the tube has its beveled end  58  here shown extending downwardly. At the maximum width  54   b , the tube has its second bevel  54   e  generally parallel to the beveled end. Rearwardly from the second bevel, the forward tube has its stepped thickness as at 59. 
     While the present invention has been related in terms of the foregoing embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described. The present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. Thus, the description is to be regarded as illustrative instead of restrictive on the present invention. 
     From the aforementioned description, a corneal endothelial tissue inserter has been described. The device is uniquely capable of allowing a surgeon to retrieve endothelial tissue from a donor&#39;s eye, grasp the tissue gently without folding, place the tissue within a small incision in a recipient&#39;s eye, and leave the tissue with the least disruption to the corneal region of the recipient&#39;s eye. The inserter provides two bevels that guide the surgeon to an angle of insertion and guide the surgeon to prevent over insertion of the instrument into a recipient&#39;s eye. The instrument and its various components may be manufactured from many materials, including but not limited to, polymers, steel, ferrous and non-ferrous metals, their alloys, select polymers, and composites. 
     Various aspects of the illustrative embodiments have been described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials and configurations have been set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that the present invention may be practiced without the is specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments. 
     Various operations have been described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention, however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. Heretofore, those skilled in the art have not recognized usage of elliptical cross section tubes, a sliding irrigation channel, a beveled nose, and a rotating end button. Therefore, the claims include such equivalent constructions insofar as they do not depart from the spirit and the scope of the present invention.