Purpose: To compare ultrasound time, energy, and micro-followability with torsional and 4D Phaco in porcine cadaver (simulating grade 1-3 cataracts) and artificial lenses (simulating grade 4+ cataracts). Setting: Alcon Research, Ltd., Lake Forest, California, USA. Design: Experimental study. Methods: 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 micro-followability in both modalities. Across all studies, balanced tip was utilized, 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. Results: 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 versus 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 to torsional (p<0.05). The bead study demonstrated enhanced micro-followability with 4D Phaco. Conclusions: UNITY VCS’s 4D Phaco improves efficiency, energy dissipated at the incision site, total energy into the eye and micro-followability compared to torsional phaco, which may translate to better postoperative outcomes.
Braga-Mele et al. (Wed,) studied this question.