ABSTRACT
Purpose: Comparison of three ultrasound (US) frequencies for phacoemulsification of hard cataracts to determine a frequency that makes phacoemulsification more efficacious and safer. Methods: A randomized controlled trial was undertaken at a medical college and hospital. In total, 207 patients with grade 5.6� 6.9 (LOCS III) senile cataract were randomized into three groups. Group I underwent phacoemulsification with 28?kHz frequency, group II with 42?kHz frequency, and group III with 53?kHz frequency. The effective phacoemulsification time (EPT) and estimated fluid usage (EFU) were compared intraoperatively. The endothelial cell parameters were analyzed for 6 months. Results: The groups were matched for age (P = 0.467), gender (P = 0.497), nuclear grade (P = 0.321), and anterior chamber depth (P = 0.635). The EPT and EFU were significantly lower in group III, compared to group II and group I, with P < 0.0001 and P < 0.0001, respectively. Postoperatively, the endothelial cell density (ECD) was significantly higher in group III at 1 month (P < 0.0001), 3 months (P < 0.0001), and 6 months (P < 0.0001). The percentages of ECD loss were also significantly lower in group III; the difference was statistically significant (P < 0.0001) up to 6 months postoperatively. Conclusion: Higher frequency ultrasound was associated with a lower EPT and EFU as well as better endothelial preservation than lower frequencies in hard cataracts