Abstract:
A method and apparatus for directing relatively gentle pulses of heated surgical fluid against the capsular bag to assist in the removal of lens epithelial cells and cortical material adhered to the capsular bag.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of cataract surgery and more particularly to a method and apparatus for polishing the capsular bag following cataract removal. 
     The human eye in its simplest terms functions to provide vision by transmitting light through a clear outer portion called the cornea, and focusing the image by way of the lens onto the retina. The quality of the focused image depends on many factors including the size and shape of the eye, and the transparency of the cornea and lens. 
     When age or disease causes the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. An accepted treatment for this condition is surgical removal of the lens and replacement of the lens function by an artificial intraocular lens (IOL). 
     In the United States, the majority of cataractous lenses are removed by a surgical technique called phacoemulsification. During this procedure, a thin phacoemulsification cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquifies or emulsifies the lens so that the lens may be aspirated out of the eye. The diseased lens, once removed, is replaced by an artificial lens. 
     Following lens removal, residual lens epithelial cells (LECs) and cortical material may remain adhered to the lens capsule. Removing this material has been increasingly recognized as being important in helping to prevent opacification of the posterior capsule (also known as a secondary cataract of PCO). PCO is generally treated by a second medical procedure known as a YAG capsulotomy during which a Nd:YAG laser is used vaporize a hole in the opacified posterior capsule to allow light to once again reach the retina. Currently, rubbing of the capsular bag with the tip of an irrigating/aspirating (I/A) handpiece is the technique used to “polish” the capsular bag. This mechanical debridement technique works well but is time consuming and risks tearing a hole in the capsular bag. 
     Therefore, a need continues to exist for a method and device for polishing the capsular bag following cataract extraction. 
     BRIEF SUMMARY OF THE INVENTION 
     The inventor of the present invention has discovered that the removal of LECs and cortical material from the capsular bag is enhanced by the use of a heated lavage technique. Such a technique may be practiced using commercially available surgical handpieces having a tip designed to direct relatively gentle pulses of heated surgical fluid against the capsular bag. 
     Accordingly, one objective of the present invention is to provide a method for the removal of LECs and cortical material adhered to the capsular bag. 
     Another objective of the present invention is to provide a handpiece that directs gentle pulses of heated surgical fluid against the capsular bag. 
     These and other advantages and objectives of the present invention will become apparent from the detailed description and claims that follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross-sectional view of the handpiece tips that may be used with the present invention. 
         FIG. 2  is a cross-sectional view of the lavage tip of the present invention taken at line  2 — 2  in FIG.  1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As best seen in  FIG. 1 , the method of the present invention is generally practiced using I/A tip  10  and lavage tip  12  simultaneously in what is called a “Bi-Manual” surgical technique. I/A tip  10  may be any conventional I/A tip and generally includes outer silicone sleeve  14  and inner aspiration tube  16 . Space  18  between sleeve  14  and tube  16  defines a pathway for irrigating solution to flow out port  20  and into the surgical site. Lavage tip  12  is of similar construction and generally contains a silicone sleeve  22  and inner tube  24  defining a first irrigating fluid path  26  that allows irrigating fluid to flow out of port  30 . Inner tube contains a cover, shroud or hood  28  at distal end  34  that helps prevent fluid flowing out of inner tube  24  from striking directly, any object directly in front of tip  12 . 
     As best seen in  FIG. 2 , tube  24  contains a plurality of interior tubes  32 , each occupying a portion of the interior diameter of tube  24 . Interior tubes  32  separate the lavage fluid flowing down and out tube  24  into a plurality in individual jets or sprays. Such jets are directed against the inside of hood  28 , thereby attenuating the velocity and force of the sprays exiting tubes  32  prior to contact with any tissue. 
     In use, I/A tip  10  is held in one hand by the surgeon and used in a conventional manner to aspirate tissue from the eye An irrigating fluid, such as a saline solution, simultaneously flows into the eye to help maintain the integrity of the eye and prevent anterior chamber collapse. Lavage tip  12  is held in the other hand by the surgeon and is connected to a suitable handpiece (not shown). One suitable handpiece is the AQUALASE® handpiece available commercially from by Alcon Laboratories, Inc., Worth, Tex. Lavage tip  12  is used to inject pulses of heated irrigating solution down tubes  24  and  32 , against hood  28  and into the surgical site. The pressure, intensity or frequency of the fluid pulses may be any suitable amount, but generally will be less than those used to remove a cataractous lens because lavage tip  12  preferably is held near capsular bag  36  so that pulses of fluid exiting hood  28  strike capsular bag  36 . Excessive pulse pressure could rupture capsular bag  36 . Buy using hood  28  and reduced lavage pulse pressures, LECs and cortical materials may be removed more easily from capsular bag  36  without rupturing capsular bag  36 . Ambient irrigating fluid is simultaneously injected down fluid path  26  and out port  30  along with the pulses of heated fluid. Such simultaneous fluid flow assists in lifted material off of capsular bag  36 . 
     This description is given for purposes of illustration and explanation. It will be apparent to those skilled in the relevant art that changes and modifications may be made to the invention described above without departing from its scope or spirit. For example, it will be recognized by those skilled in the art that the present invention may be combined with ultrasonic and/or rotating cutting tips to enhance performance.