Comparison of transversal versus torsional mode phacoemulsification for removal of hard cataracts

Aim: To compare the efficacy and safety profiles of phacoemulsification machines using transversal and torsional ultrasonic power in hard cataract surgery. Methods: The medical records of patients having NO4-6 grade hard cataract based on the Lens Opacification Classification System III, and thereby, operated by using Whitestar Signature (with transversal ultrasonic power) or Infiniti Ozil IP (with torsional ultrasonic power) phacoemulsification machines were retrospectively reviewed. At baseline, best-corrected visual acuity (BCVA), cataract grade, intraocular pressure (IOP), central corneal thickness (CCT), and biometric parameters such as lens thickness or anterior chamber depth were noted. Intraoperatively, total phaco needle time and total surgery time were recorded. Postoperatively, corneal edema severity, BCVA, IOP, and CCT was examined at first, 7th and 30th days. Results: Ninety-eight eyes of 98 patients with an average age of 69.5±10.9 (47-88) years and an average follow-up time of 3.0±1.4 (1-6) months were included into the study. Total phaco needle time and surgery time were significantly shorter in the torsional US group compared to the transversal US group (112±46 vs 171±42 seconds and 9.2±3.5 vs 13.4±3.3 minutes, respectively, both p<0.001). Severe postoperative corneal edema was more common in patients in the transversal US group compared to the torsional US group. Conclusion: Transversal ultrasonic power is more likely to cause corneal edema in patients with hard cataract possibly due to increased phaco needle time and surgery time, compared to torsional ultrasonic power. Therefore, torsional ultrasonic power-based phacoemulsification machines should be the first option, in patients whose corneas at risk of decompensation