Abstract
AIM: To investigate the impact of preoperative anterior corneal topographic parameters on the morphology of the postoperative effective optical zone (EOZ) in patients undergoing keratorefractive lenticule extraction (KLEx) and wavefront-guided LASIK (WG-LASIK). METHODS: This retrospective study included 310 eyes from patients who underwent either KLEx (via small incision lenticule extraction, 171 eyes) or WG-LASIK (139 eyes). Patients were stratified into subgroups based on the median values of spherical equivalent (SE) and anterior corneal topographic parameters. Postoperative EOZ parameters were measured 1mo after surgery and compared across subgroups. Correlation analysis and multivariable linear regression analysis were performed to explore the associations between preoperative anterior corneal topographic parameters and EOZ parameters. RESULTS: A total of 310 eyes were included (KLEx: 171 eyes from 88 patients; WG-LASIK: 139 eyes from 82 patients). The mean age was 30.65±5.67y in the KLEx cohort and 29.06±5.94y in the WG-LASIK cohort. In the KLEx cohort, SE, preoperative mean keratometry (Km), steep keratometry (K2), and anterior corneal astigmatism (K2-K1) were positively correlated with the postoperative optical zone reduction ratio (RR=EOZ/planned optical zone ×100%; all P<0.01). Multivariable regression identified SE [β=0.027, 95% confidence interval (CI): 0.022-0.032, P<0.001], Km (β=0.009, 95%CI: 0.002-0.016, P=0.014), and anterior corneal astigmatism (β=0.031, 95%CI: 0.013-0.049, P<0.001) as significant predictors of RR (R²=0.456, P<0.001). In the WG-LASIK cohort, SE was positively correlated with RR (P<0.01); K2 and anterior corneal astigmatism were positively correlated with both RR (P<0.05) and EOZ eccentricity (P<0.01). Multivariable regression showed SE (β=0.015, 95%CI: 0.007-0.023, P<0.001) and anterior corneal astigmatism (β=0.029, 95%CI: 0.012-0.047, P=0.001) were significant predictors of RR (R²=0.121, P<0.001). CONCLUSION: Preoperative anterior corneal topographic parameters, particularly anterior corneal astigmatism, significantly affect postoperative EOZ morphology in both KLEx and WG-LASIK. Additionally, Km is a predictor of EOZ reduction specifically in KLEx.