Three-Month Comprehensive Outcomes of Topography-Guided LASIK Versus Keratorefractive Lenticule Extraction (KLEx): A Prospective Contralateral Study

Abstract

Introduction: The aim of this study was to compare outcomes of topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE®) for correcting myopia and myopic astigmatism.

Methods: In this prospective, randomized contralateral study, 34 patients (68 eyes) received TG-LASIK in one eye, and SMILE in their fellow eye. Efficacy, safety, predictability, higher-order aberrations, corneal tomography, biomechanics, and patient-reported outcomes (PROs) were assessed preoperatively and up to 3 months postoperatively.

Results: Both platforms showed comparable efficacy at 3 months (TG-LASIK 1.08 ± 0.19; SMILE 0.98 ± 0.17, p = 0.055). However, TG-LASIK demonstrated quicker visual recovery, with 63% and 89% achieving uncorrected distance visual acuity (UDVA) of 20/16 or better at 1 day and 1 week, respectively, compared to SMILE (34% and 63%; p < 0.05). Safety index at 3 months did not significantly differ between TG-LASIK and SMILE (p = 0.223). TG-LASIK and SMILE had 44% and 56% of eyes within 0.13 D of spherical equivalent (SEQ) target, respectively. SMILE induced more total higher-order aberrations (HOAs), vertical coma, and oblique trefoil than TG-LASIK at 3 months (p < 0.05). Both platforms showed similar increases in epithelial remodeling, but SMILE induced thicker epithelium than TG-LASIK at the 7.0-mm nasal zonal area. No significant differences were found in corneal hysteresis (CH) or corneal resistance factor (CRF) at 3 months (p > 0.05). Reported symptoms of glare, halos, rings, starbursts, or dry eye did not significantly differ between groups at 3 months (p > 0.05). Overall, 59% of patients preferred their TG-LASIK treated eye at 1 month, but 65% of patients had no specific eye preference at 3 months.

Conclusion: TG-LASIK and SMILE demonstrate excellent and comparable efficacy, safety, and predictability at 3 months, but TG-LASIK offers faster postoperative visual recovery at 1 day and 1 week. TG-LASIK induces fewer HOAs than SMILE, but both procedures affect corneal biomechanics similarly.

Trial registration: ClincialTrials.gov identifier, NCT05611294.

Keywords: Contoura; EX500; Higher-order aberrations; KLEx; LASIK; ReLEX; SMILE; Topography-guided; VisuMax; WaveLight.

Fig. 1

a–j Nine standard refractive surgery graphs comparing visual and refractive outcomes of topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE)

Fig. 2

Comparison of cumulative uncorrected distance visual acuity (UDVA) between topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE) at a 1 day (1D), b 1 week (1 W), c 1 month (1 M), and d 3 months (3 M). *Indicates significant difference (p < 0.05) between platforms

Fig. 3

Comparison of vector analysis between a topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and b small incision lenticule extraction (SMILE)

Fig. 4

Comparison of preoperative and 3-month higher-order aberrations (HOAs) for both topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE)

Fig. 5

Zonal epithelial map analysis of preoperative and 3 months (3 M) for both topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE). – Indicates no data available; only superior, inferior, nasal, and temporal quadrants were analyzed. *Indicates significant difference (p < 0.05) between platforms

Fig. 6

Comparison of corneal hysteresis (CH) and corneal resistance factor (CRF) between topography-guided laser-assisted in situ keratomileusis (TG-LASIK) and small incision lenticule extraction (SMILE)

Fig. 7

Patient-reported eye preference at preoperative, 1 month (1 M), and 3 months (3 M)