Age and outcomes of keratorefractive lenticule extraction: visual recovery, refractive accuracy, enhancement and the contribution of an age-banded nomogram

Background/Objectives : To test whether eyes of patients aged 40 years or older reach uncorrected distance visual acuity (UDVA) of 20/20 or better 3 months after keratorefractive lenticule extraction (KLEx) less often than younger eyes, and to separate age from nomogram. Subjects/Methods : Single-surgeon registry (SmartSight, SCHWIND ATOS, 2022 to 2026) of 2817 eyes of 1455 patients (226 aged 40 or older); patient-clustered models adjusted for attempted correction, cylinder, profile, zone, era. From July 2024 the added myopic correction decreased with age; those refractions were recomputed under a common offset. Results : UDVA of 20/20 or better at 3 months was reached by 1615/1727 eyes (93.5%) under 40 and 134/157 (85.4%) at 40 or older (adjusted odds ratio (OR) 0.43, 95% confidence interval (CI) 0.25 to 0.74, P = 0.002; per decade 0.59), equally in both eras. Manifest spherical equivalent at 12 months was − 0.11 ± 0.39 and − 0.54 ± 0.57 D (adjusted difference − 0.42 D): −0.32 D in the first era and − 0.52 D in the second, where a common offset would leave − 0.19 D (− 0.45 to + 0.07). Enhancement was needed in 1.6% and 3.4% (OR 3.28); 2 or more lines of corrected acuity were lost in 0/1243 and 1/119. Conclusions : Attainment of 20/20 declined with age independently of the nomogram. In refracted eyes the residual after 40 combined an offset-related gradient with a step of about 0.3 to 0.4 D beyond it; a smaller reduction of the offset after 35 needs prospective study. Patients over 40 should be counselled accordingly.