Evolution of ultrasound in phacoemulsification: introduction of a novel ultrasound modality

To compare ultrasound time, energy, and microfollowability with torsional and 4D Phaco in porcine cadaver (simulating grade 1 to 3 cataracts) and artificial lenses (simulating grade 4+ cataracts).

Alcon Research, Ltd., Lake Forest, California.

Experimental study.

A test tube study compared torsional and 4D Phaco for a specified Kitaro artificial lens weight using UNITY Vitreoretinal Cataract System (UNITY VCS) (study 1). Time and energy needed to emulsify lens samples were recorded. Wetlab studies using artificial (study 2) and porcine lenses (study 3) compared the modalities under simulated surgical settings. A bead video was used to visualize microfollowability in both modalities. Across all studies, balanced tip was used, and fluidic parameters were consistent. Total energy into the eye (joules), energy dissipated at the incision (cumulative dissipated energy [CDE]), and ultrasound time were recorded from the machine and analyzed.

Study 1 showed 48% improvement in efficiency (2.86 ± 0.79 vs 5.48 ± 1.27 s/mg), 48% improvement in CDE (0.69 ± 0.19 vs 1.32 ± 0.30 CDE/mg), and 41% reduction in total energy (3.99 ± 1.21 vs 6.78 ± 1.71 J/mg) with 4D Phaco vs torsional. Artificial (32 torsional, 32 4D Phaco; study 2) and porcine lenses (33 torsional, 33 4D Phaco; study 3) demonstrated significantly less energy (CDE and J) and ultrasound time with 4D Phaco compared with torsional ( P < .05). The bead study demonstrated enhanced microfollowability with 4D Phaco.

UNITY VCS's 4D Phaco improves efficiency, energy dissipated at the incision site, total energy into the eye, and microfollowability compared with torsional phacoemulsification, which may translate to better postoperative outcomes.