Grooved phaco-emulsification needle

DETAILED DESCRIPTION In view of the foregoing, it is an object of the present invention to provide a phaco-emulsification needle that overcomes the drawbacks of previously known needle and sleeve arrangements by permitting the use of a small wound size, and that reduces the risk of restriction of fluid flow around the needle.
It is a further object of the invention to provide a phaco-emulsification needle that provides reduced contact area between the needle and the sleeve, thus reducing the transmission of heat to adjacent tissue, with concomitant reduction in the risk of tissue damage.
It is still a further object of the present invention to provide a phaco-emulsification needle that ensures adequate irrigant flow even in those cases where the sleeve is compressed against the exterior of the needle.
It is yet another object of this invention to provide a device for use with a phaco-emulsification needle that improves fluid flow and reduces heat transmission in those cases where the sleeve is subjected to high compressive loading by the entry wound.
These and other objects of the invention are accomplished in accordance with the principles of the present invention by providing a phaco-emulsification needle comprising a shaft having an axially extending lumen for removal of material from an eye, and at least in a middle region of the needle, one or more axially extending channels or grooves disposed externally of the lumen for supplying fluid to the eye during aspiration.
With the phaco-emulsification needle of the present invention, even if a soft plastic or elastomeric sleeve is compressed against the needle, the channels or grooves permit continued fluid flow while reducing the contact area between the sleeve and needle, thereby reducing the risk of thermal damage to the entry wound.
In a second embodiment of the present invention, a sleeve having a plurality of outwardly extending projections is provided that may be disposed on the exterior surface of a phaco-emulsification needle.
The sleeve of the second embodiment may be disposed in a reduced circumference mid-region of the needle to provide benefits similar to those of the first embodiment described hereinabove