Combined Burst Mode versus Torsional Mode Phacoemulsification for Patients with Hard Nuclear Cataracts: A Prospective Comparative Cohort Study.

Purpose: To evaluate the hard nuclear cataract surgery outcomes by comparing the combined burst mode and continuous torsional mode conducted of Centurion Vision System. Methods: Prospective comparative cohort study. Based on the Emery-Little classification, this study assigned cataract patients with nuclear density grade III to V into two groups: the combined mode group (Group A) and the torsional mode group (Group B). Endothelial cell density (ECD), central corneal thickness (CCT), and best-corrected distance visual acuity (BCVA) were evaluated at different time intervals, including 1 day, 1 week, 1 month, and 3 months. Results: 207 patients: 100 in the group A and 107 in the group B. Patients in group A with severe nuclei experienced lower cumulative dissipated energy (p = 0.007) and shorter ultrasound time (p < 0.001). Both groups exhibited a decrease in ECD after surgery, but the decrease was comparatively lower among group A patients with severe nuclei (p < 0.05). There was a notable increase in the CCT in both groups at the 1-day and 1-week time points compared to the baseline values (p < 0.001). Changes in CCT were significantly greater in group B at 1-day (p < 0.001), 1-week (p = 0.002), and 1-month (p = 0.004) intervals among patients with severe nuclei. Conclusion: Burst torsional combined with longitudinal ultrasound can be more effective for harder nuclei phacoemulsification than the continuous torsional ultrasound. Trial Registration: This study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Review Board of Fudan University's Eye & ENT Hospital. This study was registered as a clinical trial (number: NCT06991374).