Impact of preoperative mean keratometry on corneal higher-order aberrations and optical quality following cataract surgery

Abstract

Purpose To evaluate how different corneal meridian characteristics influence visual outcomes, surgically induced astigmatism (SIA), and higher-order aberrations (HOAs) following phacoemulsification with intraocular lens implantation in cataract patients. Methods Patients were divided into three groups according to preoperative mean keratometry (Kmean): flat (≤ 43.0 D), regular (43.0–46.0 D), and steep (≥ 46.0 D). Outcomes included corrected distance visual acuity (CDVA), anterior and posterior corneal astigmatism, SIA measured with the Pentacam, and HOAs assessed using both Pentacam and iTrace at 1 and 3 months postoperatively. Results CDVA, corneal astigmatism, and SIA parameters showed no significant between-group differences (all p > 0.05), with the primary clinically relevant differences lying in intrinsic HOAs and aberration changes. Preoperatively, Pentacam measurements revealed that the steep group had significantly higher anterior and posterior corneal HOAs than the flat group (p = 0.006 and <0.001, respectively). At 3 months postoperatively, the steep group maintained higher HOAs (p = 0.006 and 0.013), while changes from baseline were comparable among groups. iTrace analysis showed that the flat group had the lowest preoperative spherical aberration (SA) (p = 0.003), but exhibited a significant postoperative increase in trefoil aberration compared with the regular group (mean difference, 0.10 μm; 95% CI, 0.02 to 0.18; Padj=0.042), alongside a non-significant trend toward higher SA. Conclusion Cataract surgery provides effective and consistent refractive and visual outcomes in eyes across different Kmean profiles. Steeper corneas consistently show higher intrinsic HOAs, whereas flatter corneas demonstrate a statistically significant increase in trefoil and a non-significant trend toward higher SA compared with regular corneas.