Apparatus and method for phacoemulsification

Abstract

Apparatus and methods for phacoemulsification combine a phacoemulsification needle having an offset feature with a handpiece capable of producing longitudinal motion to create a hybrid phacoemulsification effect that is more efficient than conventional longitudinal handpiece-needle combinations and has been demonstrated under certain conditions to be more efficient than needles used with handpieces providing torsional motion. The phacoemulsification needle is of the type having a hollow passageway that terminates in a straight needle tip formed off-axis from the passageway, allowing the needle tip to move eccentrically when the needle is subjected to longitudinal vibratory motion. The tip may be flared or may be coextensive with the needle body. The tip may also be angled with respect to the needle body. The aspiration passageway formed through the needle body may be positioned or shaped to be off-axis from the needle body axis.

What is claimed is: 
     
         1 . A phacoemulsification apparatus, said apparatus comprising:
 (a) a vibratory handpiece configured to vibrate in a longitudinal direction; and   (b) a needle configured to attach to said vibratory handpiece, said needle having a means for reduction of chatter or repulsion of an internal lens of an eye during a phacoemulsification procedure.   
     
     
         2 . The phacoemulsification apparatus of  claim 1  wherein said needle includes
 an elongate needle body having (i) a proximal end terminating at a mount by which said needle body is attached to said handpiece, and (ii) a distal end for emulsifying an internal lens of an eye, said needle body defining a body central axis, said needle body having an axial length between said proximal and distal ends, taken along said needle body central axis, said needle body having an aspiration passageway extending through said needle body, said aspiration passageway defining a central path, said central path having a first length with a straight central path axis, said first length extending over a majority of the length of the needle body, 
 wherein said means for reduction of chatter or repulsion of an internal lens of an eye during a phacoemulsification procedure includes said central path axis being substantially parallel to and offset from said needle body central axis. 
 
     
     
         3 . The phacoemulsification apparatus of  claim 2  wherein said needle body has an exterior surface with a cross-section having a first shape, taken in a plane normal to said needle body central axis, and said needle body has an interior surface with a cross-section having a second shape different from said first shape, taken in a plane normal to said needle body central axis. 
     
     
         4 . The phacoemulsification apparatus of  claim 2  wherein said aspiration passageway has a substantially uniform size and shape along said body length. 
     
     
         5 . The phacoemulsification apparatus of  claim 1  wherein said needle includes an elongate needle body having (i) a proximal end terminating at a mount by which said needle body is attached to said handpiece, (ii) a distal end terminating at a tip for emulsifying an internal lens of an eye, and (iii) a body exterior surface extending between said proximal and distal ends, said needle body defining a body central axis, said needle body having an aspiration passageway extending through said needle body and said tip, said aspiration passageway having a central axis,
 wherein said means for reduction of chatter or repulsion of an internal lens of an eye during a phacoemulsification procedure includes said tip having a portion extending radially beyond said body exterior surface, taken from said body central axis, said tip portion having an axial length along said body central axis, and said aspiration passageway central axis being substantially parallel to and offset from said needle body central axis. 
 
     
     
         6 . The phacoemulsification apparatus of  claim 5  wherein said tip has a circular cross-section, taken in a plane normal to said needle body central axis. 
     
     
         7 . The phacoemulsification apparatus of  claim 5  wherein said tip has a generally square cross-section, taken in a plane normal to said needle body central axis. 
     
     
         8 . The phacoemulsification apparatus of  claim 5  wherein said tip has a generally polygonal cross-section, taken in a plane normal to said needle body central axis. 
     
     
         9 . The phacoemulsification apparatus of  claim 5  wherein said tip has an exterior surface and an interior surface terminating in a lip, and at least one of said exterior surface, said interior surface, and said lip is roughened. 
     
     
         10 . The phacoemulsification apparatus of  claim 5  wherein said tip has a leading edge and a trailing edge, said leading edge extending axially along said body central axis beyond said trailing edge, in a direction away from said body proximal end. 
     
     
         11 . The phacoemulsification apparatus of  claim 10  wherein said tip leading and trailing edges define a plane that is angled from a plane normal to said body central axis. 
     
     
         12 . The phacoemulsification apparatus of  claim 1  wherein said needle includes an elongate needle body having (i) a proximal end terminating at a mount by which said needle body is attached to said handpiece, (ii) a distal end terminating at a tip for emulsifying an internal lens of an eye, and (iii) a body exterior surface between said proximal and distal ends, said needle body defining a body central axis, said body exterior surface spaced a first distance from said body central axis at a first angular location with respect to said body central axis, said needle body having an aspiration passageway extending through said needle body and said tip, said tip defining a tip central axis and an exterior surface,
 wherein said means for reduction of chatter or repulsion of an internal lens of an eye during a phacoemulsification procedure includes said tip exterior surface spaced a second distance at a second angular location with respect to said tip central axis, said second distance being greater than said first distance, and a bend formed on said needle body such that said tip central axis is angled with respect to said needle body central axis. 
 
     
     
         13 . The phacoemulsification apparatus of  claim 12  wherein said tip has a generally square cross-section, taken in a plane normal to said tip central axis. 
     
     
         14 . A method of using the phacoemulsification apparatus, said method comprising:
 (a) acquiring the phacoemulsification apparatus of  claim 1 ;   (b) mounting said needle body to said handpiece; and   (c) operating said handpiece to vibrate said needle in a longitudinal direction eccentrically to contact, and remain in contact with, a nucleus of an eye.