Ten-Year Outcomes Of Hyperopic Flex: Refractive And Keratometric Results

To evaluate 10-year refractive stability after hyperopic Keratorefractiv Lenticule Extraction (KLEx) using Femtosecond Lenticule Extraction (FLEx) technique and to identify factors associated with long-term refractive change.

This retrospective single-center observational cohort study included 25 eyes of 13 patients who underwent hyperopic FLEx and were examined at 9 months and 10 years postoperatively. Changes in spherical equivalent (SEQ), sphere, cylinder, keratometry (K1, K2), and axis were analysed. Associations between refractive changes, age, baseline refraction, corneal, and epithelial parameters were assessed using Spearman rank correlation.

Median spherical equivalent changed from -0.50 D (IQR −1.00 to −0.13 D) at 9 months to 0.38 D (IQR −0.13 to 1.06 D) at 10 years, corresponding to a median hyperopic shift of 0.88 D. The spherical component accounted for most of the regression 0.75 D (IQR 0.50 to 1.63 D), whereas cylinder remained largely stable 0.00 D (IQR -0.25 to 0.25 D). Keratometric changes were modest, with median flattening of both K1 and K2 of −0.30 D (IQR_K1 −0.65 to −0.10 D; IQR_K2 −0.60 to −0.10 D) and correlated with refractive shift but did not sufficiently explain its magnitude. Epithelial thickness parameters were significantly associated with spherical and SEQ regression. No significant association was found with age or baseline refraction.

Hyperopic KLEx FLEx demonstrates a clinically relevant long-term hyperopic shift at 10 years that is predominantly spherical and only partially attributable to anterior corneal curvature changes. Persistent epithelial remodelling appears to contribute to long-term refractive instability independent of patients’ age. These findings indicate limited long-term refractive stability and highlight the importance of treatment planning, careful patient counselling, and enhancement strategies in hyperopic laser vision correction.