Patent Publication Number: US-2011054384-A1

Title: Sonic Device for Use in Capsule of Eye

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     This invention relates to eye surgery procedures and particularly to a technique for removing unwanted material from the lens capsule of the eye after the natural lens has been removed. Cortex material and epithelial cells remaining after the lens has been removed need to be removed to the maximum extent possible. This invention relates to an improved technique for removing these materials from the lens capsule and to a specially designed sonic tip for attachment to a conventional phacoemulsification instrument. 
     2. Description of Related Art 
     Currently during cataract surgery, a conventional phacoemulsification instrument as illustrated in  FIG. 1  is used to apply ultrasonic energy to the lens, which breaks up or emulsifies the cataract. An aspiration passageway  15  carries away the fragmented portions of the cataract and irrigation passageway  12  provides an irrigating fluid to the interior of the lens capsule to clear out the fragments and to prevent the lens capsule from collapsing. In addition to removing the lens it is desirable to remove cortex material and epithelial cells from the lens capsule prior to insertion of the replacement lens. This procedure is commonly called “irrigation and aspiration.” The lens capsule also harbors germinal and lens epithelial cells, which may be removed by “polishing” the capsule. 
     While conventional needles of the phacoemulsification instruments are typically formed with a sharp edge as shown in  FIG. 1 , some prior art needles have curved or ball shaped end portions as shown in U.S. Pat. No. 7,204,820. It is also known that by lowering the ultrasonic energy level transmitted to the surface of the tip portion of a phacoemulsification hand piece, the surface can be used to selectively clean tissue without the capsule being broken up. Such is disclosed in the U.S. Patent to Struchel et al, U.S. Pat. No. 6,159,175. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an apparatus and a method of improving the amount of unwanted matter, cortex and epithelial and other intracapsular cells, removed from the lens capsule after the natural lens has been removed, without undue delay. This is accomplished by providing a novel sonic cleaning tip that can be attached to the distal portion of a conventional phacoemulsification instrument after the instrument has been used to remove the natural cataract. The amount of energy applied to the tip by the instrument is reduced so as not to cause emulsification of eye tissue, and the tip of the instrument is then relocated into the lens capsule. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a sectional view of a conventional phacoemulsification instrument. 
         FIG. 2  is a sectional view of one embodiment of the present invention. 
         FIG. 3  is a sectional view of a second embodiment of the invention. 
         FIG. 4  is a sectional view of a third embodiment of the invention. 
         FIG. 5  is a sectional view of a fourth embodiment of the invention. 
         FIG. 6  is a sectional view of yet another embodiment of the invention. 
         FIG. 7  is a sectional view of a further embodiment of the invention. 
         FIG. 8  is a sectional view of a variation of the embodiment of  FIG. 5 . 
         FIG. 9  is a sectional view of a variation of the embodiment of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a conventional phacoemulsification instrument is shown, including an outer sleeve  11 , an inner hollow needle  14  and a threaded shoulder  17  for attachment to a source of ultrasonic energy. Passageway  15  serves as an aspiration conduit and the annular space  12  between outer sleeve  11  and needle  14  serves as an irrigation conduit for a suitable liquid. This instrument is sufficient for removing the natural lens and a major portion of the cortex material, however tiny particles of the cortex and epithelial cells are left behind. The present invention envisions the use of a specially designed sonic tip to be placed either over or within the terminal portion of a conventional needle  14  of the instrument. 
     Once the natural lens and the majority of the cortex material is removed, the surgeon withdraws the tip portion of the hand piece from the eye and in accordance with the invention places one of the sonic tips over or within the hollow needle. The distal portion of the hand piece with the sonic tip attached thereto is reinserted into the lens capsule. The power level and vacuum of the ultrasonic generator is reduced such that emulsification or capsule tear does not occur. The curved or rounded portion of the sonic tip can engage or be placed in close proximity to the inner surface of the lens capsule to remove any remaining cortex particles and cells. 
       FIG. 2  illustrates one embodiment of a sonic tip. The tip includes a tubular portion  20  that has an outer diameter that would tightly engage the inner surface of the hollow needle  13 . Alternatively the diameter of the inner section of the tubular portion  20  could be selected to slide over the outer surface of the hollow needle. The distal end of the sonic tip is formed as a semi-spherical hollow body  21 . An orifice  22  is provided through the wall of the hollow body to provide a passageway for aspirating fluid. 
     A second embodiment of the sonic tip is shown in  FIG. 3 . In this case, a hollow circular tubular member  40  terminates in a rounded surface at  41 . An orifice  42  is provided for the aspirating fluid. The inner and outer diameters of the hollow tube can be selected to either fit over the end of needle  14  or fit within the hollow portion of the needle. In the latter case, an annular shoulder  43  complimentary to the shape of the end of the needle may be provided as a stop. Alternatively, the shoulder could be formed on the interior surface when the tip is positioned over needle portion  13 . 
     In  FIG. 4  a third embodiment is shown. The shape of the sonic tip in this case has a bulbous section  31  extending outwardly from the longitudinal axis of tubular member  33 . An orifice  32  is provided in the bulbous section  31 . A stop shoulder  34  may also be provided on the exterior surface in the situation where the outer diameter of tubular member  33  is chosen so that the tip can be slidally received within the hollow needle. 
       FIG. 5  represents a fourth embodiment of the invention. The sonic tip is provided with a seal  52  that spaces the inner surface of the tubular member  50  from the outer surface  13  of the needle. Tubular member  50  has a distal semi-circular end portion  51  with an orifice  53  to accommodate the aspiration fluid. A suitable aperture  54  is provided through tubular member  50  upstream of the seal  52 . In this embodiment irrigation fluid flows through passageway  12  and out aperture  54  while orifice  53  and passageway  15  form a return path for the aspiration fluid. Alternatively the entire outer sleeve  11  could be removed and replaced with a sleeve that has sonic tip  50  formed as an integral portion of the sleeve. 
     In the embodiment of  FIG. 6 , the sonic tip  60  is formed as a U-shaped tip. As in previous embodiments, the diameter of the tubular portion may be chosen to fit within or slide over needle  14 . Also an inclined annular stop can be provided on the interior or exterior surface of the tube as discussed earlier. The sonic tip of the present invention can be made of any solid material that serves as a transmission medium for the ultrasonic energy. Suitable materials include nylon, silicone, acrylic, PMMA, metal, or other rigid material, for example. 
     In the embodiment of  FIG. 7 , the tip has the shape of a spatula having a flat surface  71  leading from tubular section  70 . The orifice  22  is located in the end portion of tubular member  70 . Tubular portion  70  may be sized to fit within or over needle  13 . 
       FIG. 8  illustrates a variation of the embodiment of  FIG. 5 . In the embodiment, the sonic tip consists of a solid tip  80  of soft material. An aspiration passageway  81  extends between the exterior of the tip and aspiration conduct  15  of the instrument. The ultrasonic needle  14  abuts the solid tip and transfers energy to the tip. 
     The embodiment of  FIG. 9  is similar to that of  FIG. 6  except for the shape of the tip portion. The tubular portion  90  is U-shaped while the end portion  91  has the shape of a spatula similar to  FIG. 7 . The tip is provided with an aspiration orifice  22  as in the other embodiments. 
     Although the present invention has been described with respect to specific details, it is not intended that such details should be regarded as limitations on the scope of the invention, except to the extent that they are included in the accompanying claims.