to compare the anatomical and clinical outcomes of cataract surgery on lenses with moderate and severe nuclear hardness by pulse mode phacoemulsification with different frequencies

127 consecutive patients with moderate or severe lens hardness were recruited; (69 with moderate and 58 with severe nuclear hardness). Patients were randomly assigned into one of these two groups: Group 1 which operated with frequency of 10 pulses/second and group 2 which operated with frequency of 60 pulses per second (pps) (63 and 60 patients, respectively). Best corrected visual acuity (BCVA), endothelial cell count, corneal edema, central corneal thickness (CCT) and effective phaco time (EPT) were evaluated one day, one week, one month and three months after the operation

The results of this study showed a statistically significant correlation between lens hardness and the final anatomical and visual outcomes; patients with moderate lens hardness had better BCVA (p<0.001), less endothelial cell loss (p=0.034) and shorter Effective phaco time (EPT) (p<0.001). EPT was shorter in group whom operated with 10 PPS phacoemulsification (p=0.18).Applied frequency also had a statistically significant effect on clinical outcomes ; patients operated with frequency of 10 pps had better BCVA (p<0.001), less corneal edema (p<0.001) CCT was only correlated with time and increased during the study course from each follow up visit to the other.

The surgical anatomical and visual outcomes with respect to endothelial cell loss and improvement in visual acuity was better in cases with moderate nuclear hardness and also effective phaco time was shorter in this group. The use of phaco with pulse mode of 10 pps frequency was accompanied with better outcomes considering visual acuity improvement, less corneal edema and effective phaco time