New Phacoemulsification Tip with a Grooved, Threaded-tip Construction

Purpose: To visually compare ultrasonic tip vibrations between a phaco tip with internal grooves (threaded tip) and a standard phaco tip during continuous-mode ultrasound (US) using ultra-high-speed digital video imaging.

Setting: Watanabe Eye Clinic, Hyogo, Japan.

Design: Experimental study.

Methods: The threaded tip was constructed by creating grooves inside a standard phaco tip using a screw. An ultra-high-speed digital video camera was used to record the image during continuous-mode US. Samples used in the test chamber during phacoemulsification included a piece of chestnut as a representative human lens sample and actual human lens fragments.

Results: Ultra-high-speed digital images showed that the threaded tip created a larger amount of cavitation than the standard phaco tip during US oscillation. Phacoemulsification of the sample using the standard phaco tip produced a chattering motion, making it difficult to maintain a steady tip position. The threaded tip produced little chattering motion, making it relatively easy to maintain a steady tip position. Once a piece of sample was gripped by the threaded tip, it was shaved and aspirated into the threaded tip without chattering motion. The mean effective phacoemulsification time (EPT) of the threaded tip was significantly shorter than that of the normal phaco tip (6.0 seconds ± 1.9 [SD] versus 15.4 ± 1.3 seconds; P=.002).

Conclusions: The threaded tip created larger amounts of cavitation and had strong destructive and holding power. This threaded construction is simple to produce and appears to be very effective for phacoemulsification.