| abstract |
An improved tip for a phacoemulsification needle having a lumen and a wall; wherein the improved tip comprises an oblique, generally concave face in side view and concentrates the majority of the effective cross-sectional area of the lumen toward the rear. An exemplary embodiment employs a maximum total face angle of 40 degrees with the face further comprising in side view from top to bottom: a first lead-in angle; a second horizontal section at a height of approximately 20-25 percent the needle diameter; and a third section defined as an arc of a circle extending tangential to the second horizontal section and extending to the top wall of the needle wherein the radius of the circle is approximately the distance between the second section and the upper wall. The improved tip is for use on hollow, ultrasonically vibrated needles of the type used for the surgical removal of cataract, abscess, hemorrhage, or other unwanted material. The improved tip is particularly designed to allow for the emulsification and aspiration of the lens of an eye in the lens chamber by increasing operative visability and reducing the incidence of pressure transients and surge, thereby reducing the danger of rupturing the posterior capsule and loss of vitreous. With the improved tip which permits material sculpting and manipulation, phacoemulsification can be accomplished without aid of another instrument. |