Comparison of torsional and longitudinal modes using phacoemulsification parameters

TLDR: Torsional phacoemulsification was more effective than longitudinal phacoEmulsification in the amount of applied fluid and the quantity of US energy expended and with the torsional method, it was possible to maintain a constant ratio of amount of fluid flow to quantity ofUS energy used, regardless of nucleus density.

Abstract: Purpose To compare phacoemulsification parameters of torsional and longitudinal ultrasound modes. Setting Ophthalmology Department, Military Health Service Institute, Warsaw, Poland. Methods This prospective study evaluated eyes 1, 7, and 30 days after phacoemulsification with an Infiniti Vision System using the torsional or longitudinal ultrasound (US) mode. Cataract classification was according to the Lens Opacities Classification System II. Nucleus fragmentation was by the phaco-chop and quick-chop methods. Primary outcome measures were phaco time, mean phaco power, mean torsional amplitude, and aspiration time. Total energy, defined as cumulative dissipated energy (CDE) × aspiration time, and the effective coefficient, defined as aspiration time/phaco time, were also calculated. Results Four hundred eyes were evaluated. The CDE was statistically significantly lower in the torsional mode for nucleus grades I, II, and III (P .05). Aspiration time was statistically significantly shorter in the torsional mode than in the longitudinal mode for nucleus grades III and IV (P Conclusions Torsional phacoemulsification was more effective than longitudinal phacoemulsification in the amount of applied fluid and the quantity of US energy expended. With the torsional method, it was possible to maintain a constant ratio of amount of fluid flow to quantity of US energy used, regardless of nucleus density.