Efficacy and safety of the eight-chop technique in phacoemulsification for patients with cataract

Abstract

Purpose: The aim of this study was to estimate the efficacy of the 8-chop technique in phacoemulsification surgeries of patients with cataract.

Setting: Sato Eye Clinic, Chiba-ken, Japan.

Design: Prospective study.

Methods: Patients were classified into 3 groups (Grade II, Grade III, and Grade IV; n = 50 each) according to the firmness of their lens nuclei. The Eight-chopper I was used for Grade II, Eight-chopper II for Grade III, and Lance-chopper for Grade IV. The best-corrected visual acuity, intraocular pressure (IOP), and endothelial cell density were evaluated at 7 and 19 weeks postoperatively. The primary outcome measures were the mean operative time, mean phaco time, cumulative dissipated energy (CDE), and volume of fluid used.

Results: 150 cataract surgeries were performed. The operative time (minutes), phaco time (seconds), CDE, and volume of fluid used (milliliters) differed significantly among the 3 groups, increasing in the following order: Grade II, Grade III, and Grade IV ( P < .01). The corneal endothelial cell density did not decrease significantly in the 3 groups at 19 weeks postoperatively ( P = .09). The rate of endothelial cell loss was 0.9% ± 5.9%, 1.0% ± 10.3%, and 5.3% ± 11.1% in the Grade II, III, and IV groups at 19 weeks postoperatively, respectively. There were significant reductions in the IOP at 7 and 19 weeks postoperatively compared with the preoperative IOP in the 3 groups ( P < .01).

Conclusions: The 8-chop technique was effective and safe in phacoemulsification for patients with cataracts with lens nuclei of varying hardness.

Figure 1.

Eight-choppers and Universal II prechopper. a: the Eight-chopper I (SP-8193); b: the Eight-chopper II (SP-8402); c: the Lance-chopper (SP-9989); and d: The Universal II Prechopper (AE-4192).

Figure 2.

a: First, the lens nucleus is divided into hemispheres using the Eight-chopper. b: Then, the lens nucleus is rotated 90 degrees and divided into quadrants. c: The lens nucleus divided into quadrants is rotated 45 degrees and divided into 6 segments. d: Finally, the remaining quadrants of the lens nucleus are also divided to complete the eight segmentation.

Figure 3.

a: First, the lens nucleus is divided into hemispheres using the Lance-chopper, while the nucleus sustainer (AE-2530) is inserted through the side port to support the equator of the lens nucleus. b: Then, the lens nucleus is rotated 90 degrees and divided into quadrants. c: The lens nucleus divided into quadrants is rotated 45 degrees and divided into 6 segments. d: Finally, the remaining quarter of the lens nucleus is also divided to complete the eight segmentation.