Comparing high and low energy outcomes on day one for SmartSight myopic-astigmatism treatments with the SCHWIND ATOS: a retrospective case series

Abstract

Background: Impact of low energy asymmetric spacings vs. high energy symmetric spacings on the immediate/early (postoperative day 1 (POD1)) outcomes of SmartSight lenticule extraction for myopic astigmatism with a new femtosecond laser system.

Methods: The first 112 eyes of 56 patients consecutively treated using low energy asymmetric spacings (Group A; Study group) were compared at POD1 to the last 112 eyes of 56 patients consecutively treated using high energy symmetric spacings (Group S; Controls). Mean age of the patients was 28 ± 5 years with a mean spherical equivalent of -4.41 ± 1.76 diopters (D) and a mean magnitude of refractive astigmatism of 0.89 ± 0.82 D.

Results: Laser Energy was -25 ± 1nJ lower for asymmetric treatments (p < .0001); Spot and Track distances were + 0.7 ± 0.1 µm larger and -0.8 ± 0.1 µm tighter for asymmetric treatments, respectively (p < .0001 for both). At POD1, astigmatism was -0.08 ± 0.02D lower for asymmetric treatments (p < .0003); uncorrected and corrected visual acuities (UDVA and CDVA, respectively) were -0.03 ± 0.01logMAR better for asymmetric treatments (p < .0007); differences between postop UDVA and preop CDVA along with change in CDVA were + 0.3 ± 0.1lines better for asymmetric treatments (p < .0003).

Conclusions: Lenticule extraction treatment using SmartSight is safe and efficacious already at POD1. Findings suggest that low energy asymmetric spacings may further improve the immediate and short-term outcomes of SmartSight lenticule extraction in the treatment of myopic astigmatism compared to conventional settings (high energy symmetric spacings).

Keywords: Corneal laser refractive surgery; Early outcomes; Femtosecond laser; Immediate and short-term visual recovery; Immediate outcomes; Lenticule; Lenticule extraction; Myopic astigmatism; Small incision; Smoothness.

Fig. 1

Standard graphs for reporting astigmatism outcomes of refractive surgery at POD1 comparing the first 112 eyes of 56 patients consecutively treated using low energy asymmetric spacings (Group A; Study group) vs. the last 112 eyes of 56 patients consecutively treated using high energy symmetric spacings (Group S; Controls). A Cumulative Snellen Visual Acuity. B Difference between achieved UDVA at POD1 and preoperative CDVA baseline. C Change in Snellen lines of CDVA. D Scattergram of the SEq. E Predictability of the SEq respect to the target. F Predictability of the refractive astigmatism respect to the target. G Scattergram of the astigmatic correction. H Predictability of the refractive astigmatic axis respect to the target