Comparison of pre-chop technique using a reverse chopper and classic stop-and-chop technique in the treatment of high myopia associated with nuclear cataract

Abstract

Background: To evaluate the safety and efficacy of the pre-chop technique using a novel reverse chopper vs. the classic stop-and-chop technique in phacoemulsification for patients with high myopia and associated grade III-IV nuclear cataracts.

Methods: In this prospective cohort study, a total of 44 consecutive patients (44 eyes) with grade III-IV nuclear cataracts who were admitted to our hospital for cataract surgery between March 2018 and September 2018 were enrolled. All patients had ocular axial length > 27 mm and myopic refraction more than -10 diopters. Patients were randomly divided into a pre-chop group and stop-and-chop group using a randomization table. Nucleus splitting was performed surgically in both groups using either the pre-chop technique with reverse chopper or the classic stop-and-chop technique.

Results: Postoperative visual acuity was significantly improved in both groups compared with preoperative values. Significantly better visual acuity, lower degree of corneal edema and lower rates of corneal endothelial cell loss were observed in the pre-chop group compared to those in the classic stop-and-chop group. No complications were reported in either group.

Conclusions: In treating patients with high myopia associated with grade III-IV cataracts, the pre-chop technique using a reverse chopper reduces damage to corneal endothelial cells and improves visual acuity better than the classic stop-and-chop technique.

Keywords: Cataract extraction; High myopia; Phacoemulsification; Pre-chop technique; Reverse chopper; Stop-and-chop technique.

Fig. 1

Devices for pre-chop technique using a reverse chopper. A A reverse chopper. B The meridional section of the lens shows the locations of the two choppers. C The trajectory of the lower hook holding the nuclear splitting hook