Comparison of the Phaco Chop and the Mini Chop Methods in Cataract Surgery

ABSTRACT

PURPOSE: To compare effective phacoemulsification time (EPT), the severity of corneal swelling and corneal endothelial cell density after cataract surgery between the phaco chop method and the mini chop method. METHODS: Cataract surgery was performed by phaco chop (15 eyes) or by mini chop (13 eyes) method in 28 eyes of 27 patients. The nuclear opacity of cataract grade was more than 5 on LOCS (Lens opacities classification system) III. EPT and the amount of irrigated BSS solution were measured during the operation. Corneal thickness (preoperative, immediate postoperative, postoperative 1 day, 1 week, 1 month, and 3 months) and corneal endothelial cell density (preoperative, postoperative 1month and 3 months) were measured. RESULTS: The EPT of phaco chop group was 5.2 sec and that of mini chop was 1.0 sec (p=0.000). The amount of irrigated BSS was 193.7 ml and 170.4 ml in the phaco chop group and the mini chop group, respectively. The increase in corneal thickness was 3.2% and 0.9% at immediately after surgery (p=0.128), 19.0% and 10.5% at postoperative 1 day (p=0.088), 5.7% and 1.5% at postoperative 1 week (p=0.080), 0% and -1.3% at postoperative 1 month (p=0.717), and -0.4% and -0.6% at postoperative 3 months (p=0.890) in the phaco chop group and the mini chop group, respectively. Corneal endothelial cell density decreased 23.0% in the phaco chop group and 9.4% in the mini chop group at postoperative 1 month (p=0.005) and 22.9%, 12.6%, at 3 months respectively (p=0.036). CONCLUSIONS: The mini chop technique reduced permanent endothelial cell damage in comparison with the phaco chop method and might be more effective in decreasing corneal swelling during the early postoperative period than the phaco chop method.