Comparison of phaco-chop, divide-and-conquer, and stop-and-chop phaco techniques in microincision coaxial cataract surgery

PURPOSE: To compare the outcomes of coaxial microincision cataract surgery (MICS) performed with 3 phacoemulsification techniques (phaco-chop, divide-and-conquer, and stop-and-chop) according to cataract density. SETTING: Bucheon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, South Korea. DESIGN: Prospective randomized clinical trial. METHODS: Eyes with nuclear density from grade 2 to 4 were randomly subdivided into 3 groups (phaco-chop, divide-and-conquer, and stop-and-chop). Intraoperative measurements included ultrasound time (UST), mean cumulative dissipated energy (CDE), and balanced salt solution use. Clinical measurements included preoperative and 1 day, 1 month, and 2 month postoperative corrected distance visual acuity, central corneal thickness, and endothelial cell count. RESULTS: Intraoperative measurements showed significantly less UST, CDE, and balanced salt solution use with the phaco-chop technique than with the divide-and-conquer and stop-and-chop techniques in the grade 4 cataract density group (P<.05). The percentage of endothelial cell loss was significantly lower in the phaco-chop group than in the divide-and-conquer and stop-and-chop groups in the grade 4 cataract density group 2 months after cataract surgery (P<.05). CONCLUSIONS: All 3 techniques may be effective for coaxial MICS in mild and moderate cataracts. However, in eyes with hard cataract having coaxial MICS, the phaco-chop technique can be more effective for lens removal, with less corneal endothelial damage, than the divide-and-conquer and stop-and-chop techniques.