Effects of the Eight-Chop Technique in Phacoemulsification on Intraocular Pressure in Patients with Primary Open-Angle Glaucoma and Controls

Purpose: To investigate the long-term effects of phacoemulsification by the eight-chop technique on intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG). Methods: This study comprised the eyes of patients with cataracts who had undergone phacoemulsification and posterior chamber intraocular lens implantation. Patients with corneal disease or opacity, uveitis, pupillary dilation problem, and previous trauma or surgery were excluded. Cataract surgeries were performed using the eight-chop technique. The operative time, phaco time, aspiration time, cumulative dissipated energy, and volume of fluid used were measured intraoperatively. Best-corrected visual acuity and corneal endothelial cell density (CECD) were measured postoperatively at 7 and 19 weeks.Results: In total, 150 eyes of 98 patients were followed up. The POAG group had a CECD loss rate of 1.5% and 1.2% at 7 and 19 weeks postoperatively, respectively. The control group had a CECD loss rate of 0.8% and 1.4% at 7 and 19 weeks postoperatively, respectively. The IOP reduction rate at 1 year postoperatively was 12.7% and 12.5% in the POAG and control groups, respectively. In the subgroups with preoperative IOP below 15 mmHg, IOP decreased significantly (p<.01, paired t-test) at 7 weeks and remained significantly lower at 1 year postoperatively.Conclusions: The eight-chop technique remained effective in lowering IOP after 1 year in the POAG and control groups. This effect did not diminish in patients preoperative IOP below 15 mm Hg. Phacoemulsification using the eight-chop technique may be effective for patients with glaucoma.