Impact of crystalline lens opacification on effective phacoemulsification time in femtosecond laser-Assisted cataract surgery

摘要

WE WOULD LIKE TO THANK MAYER AND ASSOCIATES1 FOR describing reduction of ultrasound energy with femtosecond laser phacofragmentation. However, the authors' methodology is ambiguous and may ignore the contribution of torsional power during phacoemulsification. Mayer and associates used the Infiniti Vision System (Alcon, Inc, Ft. Worth, Texas, USA). Ambiguity results because the Infiniti Metrics Display does not provide Effective Phaco Time (EPT). Rather, it provides Phaco Time, defined as the "total time phaco power was active," and 2 metrics of phaco power, "Average Phaco Power" and "Average Phaco Power in Position 3." Average Phaco Power is defined as "Average phaco power over time when phaco power was applied. For example, if Ultrasound Burst mode was selected and 100 mS burst pulses at 70% stroke were generated once a second, the Average Power would record 70%." Average Phaco Power in Position 3, on the other hand, represents "Average phaco power over time when phaco power was applied in foot pedal position 3. This takes into account the U/S modulation aspects, resulting in a significantly lower reading than Average phaco power. For example, if Ultrasound Burst mode was selected and 100 mS burst pulses at 70% stroke were generated once a second, the Average Power in Position 3 would record 7%."