Ultrasound energy in phacoemulsification: a comparative analysis of phaco-chop and stop-and-chop techniques according to the degree of nuclear density.

BACKGROUND AND

OBJECTIVE

To evaluate the amount of ultrasound energy used, corneal endothelial cell loss, and central corneal thickness using the phaco-chop and stop-and-chop techniques for cataracts with different degrees of nuclear density.

PATIENTS AND

METHODS

One hundred two eyes of 51 patients with bilateral senile cataract were included. Each eye was randomly assigned to have either phaco-chop or stop-and-chop nucleofractis during phacoemulsification. The groups were divided into two subgroups according to the nuclear density. The effective phacoemulsification time, endothelial cell density, and central corneal thickness were analyzed.

RESULTS

The mean effective phacoemulsification time was similar between the groups in moderately dense nuclei (2.17 +/- 1.33 vs 1.33 +/- 1.05 seconds; P = .41). However, the phaco-chop technique required less effective phacoemulsification time than the stop-and-chop technique in dense nuclei (3.86 +/- 4.18 vs 6.70 +/- 5.43 seconds; P = .01). The endothelial cell loss and the central corneal thickness did not vary significantly between the groups.

CONCLUSION

The phaco-chop technique requires lower ultrasound energy for nuclear management than the stop-and-chop technique in dense cataracts and the resulting endothelial loss was similar in both techniques.