Abstract:
An improved nozzle for injecting an IOL through a corneal incision and into a human eye has a nozzle with upper, or upper and lower tapers formed at the end thereof to facilitate passage of the nozzle into the incision. A textured surface formed on the upper taper helps to keep the nozzle from slipping when it is inserted.

Description:
[0001]     This invention relates to foldable intraocular lenses and, more particularly, to improved nozzles for injectors and cartridges used for injecting intraocular lenses into the eye. Applicant claims priority from U.S. Provisional Patent Application entitled “Improved Intraocular Lens Injection Nozzle”, Ser. No. 60/682,179, filed May 18, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     A common ophthalmological surgical technique for treating cataracts and other diseases of the lens is to fractionate, emulsify and remove the diseased lens and replace it with a synthetic, plastic lens. To do so, an incision is made in the eye through which the diseased lens is removed and through which the new lens is inserted.  
         [0003]     It is desirable to make the incision for removing the diseased lens and inserting the new lens as small as possible. This aids in shortening recovery time and limits the leakage of fluid through the incision after surgery without requiring sutures.  
         [0004]     When originally introduced, replacement intraocular lenses (IOLs) were made from rigid plastics such as polymethylmthacrylate and required a relatively large corneal incision through which the lens would be inserted. Such incisions had to be sutured to limit the loss of fluid from the eye. The development of the soft lens, made from materials such as hydrogels, silicones and soft acrylics made it possible to fold or roll the lens prior to insertion. It is now a common surgical technique to fold such an IOL, insert it through the incision and allow the lens to unfold and position itself within the eye. When folded, the lens needs a much smaller incision for insertion than if the lens were inserted in its fully unfolded state.  
         [0005]     Examples of foldable IOLs and systems for injecting them are well represented in the prior art.  
         [0006]     U.S. Pat. No. 5,947,976 (Van Noy et al) teaches and describes an asymmetric IOL injection cartridge having an asymmetric bore. The IOL is inserted into the cartridge in its unfolded state, and when pushed through the cartridge, is partially folded when it exits the cartridge tip.  
         [0007]     U.S. Pat. No. 5,976,150 (Copeland) teaches and describes an IOL injection system using a foldable substrate to compress and fold an IOL around an outer edge of the substrate. The folded assembly is then placed in an injector and expressed through the injector nozzle into the eye.  
         [0008]     U.S. Pat. No. 6,083,231 (Van Noy et al) teaches and describes an asymmetric IOL injection cartridge. This patent is a continuation in part of the previously described U.S. Pat. No. 5,947,976 and adds to the disclosure in the &#39;976 patent a peg used to engage the haptic on an IOL to keep the haptic in position as the lens is injected through the injector nozzle.  
         [0009]     U.S. Pat. No. 6,143,001 (Brown et al) teaches and describes an asymmetric intraocular lens injection cartridge. This patent is a continuation in part of the previously described U.S. Pat. No. 6,083,231 as well as the &#39;976 patent. Brown et al adds to the teachings of the prior mentioned patents a modified asymmetric bore which acts to fold the IOL as it is forced through the bore and the cartridge nozzle.  
         [0010]     U.S. Pat. No. 6,398,789 (Capetan) teaches and describes an IOL injector cartridge similar in construction to the cartridge shown in the &#39;976, &#39;231 and &#39;001 patents and which adds to the elements of those patents a heat-retention agent to keep the IOL warmed during the injection process.  
         [0011]     U.S. Pat. No. 6,537,283 (Van Noy) teaches and describes an IOL shipping case and injection cartridge comprising an injection cartridge to which a case for an unfolded IOL is hingedly attached. The case can be rotated to align the lens with the central bore of the cartridge to let the lens thereafter be pushed through the cartridge and expressed through the cartridge tip.  
         [0012]     U.S. Pat. No. 4,681,102 (Bartell) teaches and describes apparatus and method for insertion of an IOL where the system consists of an injector and a foldable load chamber within which the unfolded lens is placed. The chamber is then folded shut thereby folding the lens in half and a plunger is used to force the lens from the load chamber through a tip and into the eye.  
         [0013]     These IOL delivery systems share a common characteristic: however the IOL is manipulated through the injector or cartridge, it inevitably is expressed or discharged through a nozzle into the eye. This is accomplished by positioning the tip of the nozzle at the incision, passing the nozzle into or through the incision into the anterior chamber and then expressing the IOL from the cartridge and through the nozzle allowing the IOL to unfold and position itself properly.  
         [0014]     Although such fold-and-deliver systems have made it possible to use a smaller incision, the incision must still be of a size to allow the nozzle tip to pass therethrough. The present invention improves this process by shaping the nozzle tip to more easily be accommodated by the incision and to make possible the use of even smaller incisions.  
       SUMMARY OF THE INVENTION  
       [0015]     The present invention comprises a nozzle having a tip which may be used as the exit nozzle from an IOL-holding cartridge or from an injector through which an already folded IOL is forced. The tip features an exterior taper which minimizes the size of the nozzle at the incision allowing the tip to be more easily inserted through the incision. Thus, the incision need not be large enough to accommodate the major dimension of the nozzle that can be stretched as the tip is inserted through the incision and thereafter returned to its original size when the nozzle tip is withdrawn from the incision. A textured surface is formed on the upper taper to inhibit the nozzle from slipping when it is inserted into the incision.  
         [0016]     These and other advantages of the present invention will become apparent upon consideration of the accompanying descriptions and the accompanying drawings in which: 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a side elevational view of a prior art IOL injection cartridge;  
         [0018]      FIG. 2  is a top plan view of the prior art cartridge shown in  FIG. 1 ;  
         [0019]      FIG. 3  is a sectional view taken along line  3 - 3  of  FIG. 2 ;  
         [0020]      FIG. 4  is a partial sectional schematic view illustrating the placement of the nozzle tip at the incision;  
         [0021]      FIG. 5  is a partial sectional schematic view demonstrating a first preferred embodiment of the present invention having a partial upper exterior taper;  
         [0022]      FIG. 5A  is an end view of the nozzle of  FIG. 5 ;  
         [0023]      FIG. 6  is a partial sectional schematic of a second preferred embodiment of the present invention, having a partial lower exterior taper;  
         [0024]      FIG. 6A  is an end view of the nozzle of  FIG. 6   
         [0025]      FIG. 7  is a partial sectional schematic view of a third preferred embodiment of the present invention showing both upper and lower exterior tapers;  
         [0026]      FIG. 7A  is an end view of the nozzle of  FIG. 7 ;  
         [0027]      FIG. 8  is a partial sectional schematic of a fourth preferred embodiment of the present invention, having a roughened, textured surface formed on the upper exterior taper;  
         [0028]      FIG. 9  is an end view of a nozzle such as shown in  FIG. 8  with a textured surface formed by upstanding bumps; and  
         [0029]      FIG. 10  is a partial sectional schematic showing the insertion of the nozzle of  FIG. 8  into an eye. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     Referring now to  FIG. 1 , the numeral  10  identifies generally a prior art intraocular lens injection cartridge as shown and described in U.S. Pat. No. 6,537,283. Cartridge  10  has a hollow body  12  to which is attached a lens holder  14  and within which an IOL  16  is held. As seen in  FIGS. 2 and 3 , this particular injection system allows the cartridge  10  to accept IOL  16  in its unfolded state and fold it as it travels through the cartridge.  
         [0031]     As seen in  FIGS. 1, 2  and  3 , prior art cartridge  10  includes a nozzle  18  terminating at a tip  20 . It is the nozzle  18  that is inserted into the corneal incision and through which IOL  16  is ultimately expressed. As seen in  FIG. 3 , cartridge  10  has an interior bore  22  communicating with a nozzle passage  24  along which IOL  16  is passed. The &#39;283 patent includes a full description of the shaping of bore  22  which accomplishes the folding of IOL  16  as it passes along bore  22  and ultimately, through nozzle  18  and tip  20  via nozzle passage  24 .  
         [0032]     As seen in  FIG. 1 , tip  20  is formed by cutting or otherwise shaping nozzle  18  at an angle, resulting in a lead edge  26  and a trailing edge  28 . For the purposes of the examples presented herein, the lead edge is that part of the rim forming the nozzle opening that is the farthest in an axial direction from body  12 , while the trailing edge is that portion of the rim that is the closest in an axial direction to body  12 . As seen schematically in  FIG. 4 , when nozzle  18  is positioned at incision  30 , formed through cornea  32 , lead tip edge  26  is typically inserted into incision  30  and thereafter, trailing tip edge  28  contacts incision  30 .  
         [0033]     As illustrated in  FIG. 4 , where incision  30  is slightly smaller than the outside diameter of nozzle  18 , the surgeon may encounter some difficulty in passing nozzle  18  through incision  30 , due to the contact between tip  20  and cornea  32 .  FIG. 4  illustrates the situation that can occur when trailing edge  28  contacts the exterior surface of cornea  32 .  
         [0034]     Referring to  FIG. 5 , a first embodiment of the present invention provides a taper  34  to an exterior portion of nozzle  18 . Although the prior art cartridge shown in  FIGS. 1, 2 ,  3  and  4  is illustrated as a specific device in the &#39;283 patent, it is to be understood that the configurations shown as preferred embodiments in the present description applies to this tip and others as well.  
         [0035]     In the preferred embodiment shown in  FIG. 5 , tapered nozzle section  34  extends about a portion of the circumference of nozzle  18 , preferably including that portion of nozzle  18  which forms leading edge  26 . As seen in  FIG. 5  when leading edge  26  is inserted into incision  30 , tapered nozzle section  34  allows nozzle  18  to be inserted into incision  30  even though incision  30  may close to slightly smaller in size than nozzle  18 . As tapered nozzle section  34  enters incision  30  it exerts less force than if the taper were not present.  
         [0036]     As seen in  FIG. 5A , tapered section  34  covers a selected portion of the upper exterior surface of nozzle  18  with the remaining surface being without a taper. As seen in  FIG. 5A  tapered section  34  preferably includes lead edge  26 .  
         [0037]     In another embodiment of the present invention, the length of tapered nozzle section  34  may be selected to enable that portion of nozzle  18  to pass through incision  30  without reaching the full diameter of nozzle  18 . As an example, a typical corneal incision tunnel is about 1 mm in length. Making tapered nozzle section  34  about 2 mm in length will allow section  34  to pass through incision  30  without being stretched to the full diameter of nozzle  18 .  
         [0038]     Referring now to  FIG. 6 , a second preferred embodiment of the invention is shown wherein a tapered section  36  is formed on the lowermost portion of nozzle  18 , preferably including trailing edge  28 . With this type of configuration an incision  30  large enough to accommodate lead edge  26  yet closed to a size less than the full diameter of nozzle  18  can be entered and opened gradually by tapered section  36 .  
         [0039]     As seen in  FIG. 6A  tapered section  36  covers a selected portion of the lower external surface of nozzle  18  and preferably includes trailing edge  28 . The remaining portion of nozzle  18  remains untapered.  
         [0040]     Referring now to  FIG. 7 a  third preferred embodiment of the present invention is shown wherein nozzle  18  has formed thereon an upper tapered section  38  and a lower tapered section  40 , thought to facilitate entry into particularly tight incisions  30 . When combining such an upper and lower taper consideration must be given to maintaining the rigidity of nozzle  18  by not removing too much material to form tapers  38 ,  40 . It is contemplated that with a sufficiently rigid material a taper can be formed about the entire periphery of nozzle  18 .  
         [0041]     Referring to  FIG. 7A  upper tapered section  38  is seen to include lead edge  26 , while lower tapered section  40  is seen to include trailing edge  40 .  
         [0042]     Referring now to  FIG. 8 , the numeral  42  identifies a textured surface formed on taper  38  of nozzle  18 . Textured surface  42  is preferably formed by roughening the surface, such as by sandblasting but, as seen in  FIG. 9 , textured surface  42  can also be molded as a series of “bumps”  44  extending above the surface of taper  38 . Other shapes, such as raised ridges can also be used to create the desired texturing.  
         [0043]     Referring now to  FIG. 10  nozzle  38  is shown extended into incision  30  with textured surface  42  in contact with the upper edge  46  of incision  30 . Textured surface  42  provides a sufficiently non-slip surface to decrease the possibility that nozzle  18  will slip when inserted into incision  30 .  
         [0044]     While the foregoing 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.