Effect of steep-axis incisions on anterior and posterior corneal astigmatism and higher-order aberrations after cataract surgery

Abstract

To compare the effects of steep-axis versus superior corneal incisions on visual acuity, astigmatism correction, and higher-order aberrations (HOAs) in patients undergoing phacoemulsification with intraocular lens implantation. Prospective, case-control, single-center study. This study enrolled patients with preoperative corneal astigmatism <2.5 diopters. Outcomes included corrected distance visual acuity (CDVA), anterior and posterior corneal astigmatism, surgically induced astigmatism measured with Pentacam, and higher-order aberrations (HOAs) assessed using Pentacam and iTrace at 1 and 3 months postoperatively. A total of 148 right eyes from 148 patients were analyzed, including 56 in the steep-axis incision group and 92 in the superior-incision group. CDVA did not differ significantly between groups at 3 months ( p  = 0.617). Steep-axis incisions produced significantly lower anterior corneal astigmatism ( p  = 0.006) and a greater flattening effect ( p  < 0.001) at 3 months. No significant intergroup differences were observed in total HOAs of the total cornea, anterior cornea, or posterior cornea within the 6-mm zone by either Pentacam or iTrace. Subgroup analysis of steep-axis orientations (with-the-rule, against-the-rule, oblique) revealed no significant differences in outcomes. Steep-axis incisions effectively reduce anterior corneal astigmatism without increasing HOAs, representing a practical option for correcting mild-to-moderate astigmatism in cataract surgery.