Comparison of Biaxial and Coaxial Irrigation and Aspiration for Lens Cortex Removal in Phacoemulsification

Abstract

Objective: To evaluate the clinical results of cortex removal with biaxial irrigation and aspiration (IA) compared with coaxial IA in phacoemulsification. Methods: This prospective study enrolled cataract patients who underwent phacoemulsification and intraocular lens implantation at the Second People's Hospital of Hefei Affiliated to Anhui Medical University. The patients were divided into two groups (each with 30 patients, 30 eyes) based on the cortex removal mode: biaxial IA and coaxial IA. For the biaxial IA group, we made three corneal incisions: one main incision at 1200 (phaco tip) and two side port incisions at 300 and 900 (irrigation and aspiration). For the coaxial IA group, we made one main incision and one side port incision at mutually perpendicular lines. In both groups, normal hydrodissection was set and the nucleus was aspirated with ultrasound phacoemulsification energy. The residual cortex was removed, and posterior capsule polishing was performed using either biaxial IA or coaxial IA. The time (in seconds) required for the removal of the cortex measured from instrument insertion in the eye until aspiration tip removal. Residual cortex, posterior capsule ruptures, visual acuity, and corneal astigmatism were recorded. Data were analyzed by the Mann-Whitney test, chi-square test, and Fisher's exact test. Results: The cortex removal time was 118 ± 10 seconds for the biaxial IA group and 150 ± 16 seconds for the coaxial IA group (Z=-6.174, P 0.05). One posterior capsular tear occurred in the coaxial IA group. Conclusions: Biaxial IA significantly reduced cortex removal time compared to coaxial IA. Biaxial IA appears to be safer and more efficient than coaxial IA in cortex removal. Key words: irrigation/aspiration; cortex; biaxial; phacoemulsification