AIM: To compare the clinical efficacy of the Balanced energy system versus the conventional torsional ultrasound system in phacoemulsification surgeries for cataracts with varying nuclear hardness.

METHODS: In this study, 120 patients(122 eyes)with age-related cataracts scheduled for surgery between November 2021 and November 2022 at our hospital were randomly divided into two groups: 58 patients(59 eyes)in the experimental group underwent surgery using the Balanced energy system, while 62 patients(63 eyes)in the control group were treated with the conventional torsional ultrasound system. Intraoperative cumulative dissipated energy(CDE), case time(CT), aspiration time(AST), and estimated fluid used(EFU)were recorded. Patients were followed-up for 3mo to examine and record the best-corrected visual acuity(BCVA)and corneal endothelial cell density(ECD), and to calculate the rate of endothelial cell loss.

RESULTS: Comparing the intraoperative parameters between the two groups, there was no significant difference in CT(P>0.05), but the CDE, AST and EFU of the patients in the experimental group were lower than those of the control group(P<0.05), and the CDE of patients with grade III nuclear hardness in the experimental group was lower than the control group(P<0.05), CDE, AST and EFU in patients with grade IV nuclear hardness were lower than those in the control group(P<0.05). After 3mo of follow-up, BCVA in both groups improved significantly, and the experimental group recovered faster than the control group. At 3mo after surgery, the ECD of the two groups of patients was reduced compared with that before surgery(P<0.01), but there were no significant differences in ECD and endothelial cell loss rates between the experimental and control groups before and at 3mo after surgery(P>0.05). In grade IV nuclear hardness cataracts, the rate of endothelial cell loss in the experimental group was significantly lower than that in the control group(4.63%±4.10% vs. 6.63%±4.49%, P<0.01).

CONCLUSION: The Balanced energy system and the conventional torsional ultrasound system both show high safety and efficiency in phacoemulsification of cataracts with different nuclear hardness. However, the former demonstrates substantial advantages in cases with dense nuclei, offering lower ultrasound energy, shorter aspiration and infusion times, and reduced volume of infusion fluid.