Effect of ablation-zone diameter on whole-corneal higher-order aberrations after LASEK: a retrospective study

To evaluate whether modest differences in programmed ablation-zone diameter (AZD) during LASEK affect postoperative whole-corneal higher-order aberrations (HOAs), with emphasis on spherical aberration (SA) and coma (CA).

This retrospective single-center observational study included 120 right eyes that underwent LASEK between January 2020 and June 2025. Eyes were grouped by programmed AZD: 5.75 mm (n = 41), 6.00 mm (n = 40), and 6.25 mm (n = 39). Corneal HOAs were measured by Pentacam at baseline, 1 and 3 months. Analyses included absolute changes, per-diopter normalization, SEQ-matched comparisons, and ablation-depth-matched sensitivity analyses.

All groups showed significant postoperative increases in total HOA, SA and CA at 3 months (P < 0.001). In unadjusted analyses, larger programmed AZDs exhibited smaller absolute increases in total HOA, SA and trefoil (P < 0.001). After per-diopter normalization, most zone-dependent differences were largely attenuated (P > 0.05 for most comparisons). SEQ-matched analyses showed that AZD enlargement reduced SA but tended to increase CA, without a uniform reduction in total HOA. After ablation-depth matching, larger programmed AZD was not associated with additional HOA induction.

In LASEK, larger programmed AZDs were associated with smaller unadjusted HOA and SA induction at 3 months; however, these associations were substantially influenced by baseline refractive magnitude and ablation depth. AZD selection should be individualized, balancing refractive correction, tissue removal, corneal safety, and centration strategy.