Evaluating The Inter-Device Variability In The 1-Year Refractive And Visual Outcomes Among 4 Different Units Of Schwind Atos At 4 Laser Centres Used By A Single Surgeon

Published 2025 - 43rd Congress of the ESCRS

Reference: FP14.03 | Type: Free paper | DOI: 10.82333/r2rm-fh69

Authors: Chadsupad Tharawan* ¹ , Pakornkit Phrueksaudomchai ² , Monrada Amorntipsakul ¹ , Promporn Patarajierapun ³ , Woranart Tattiyakul ¹

¹Ophthalmology,Thammasat University,Pathumthani,Thailand, ²Ophthalmology,Thammasat University,Pathumthani,Thailand;Ophthalmology,Thammasat University Hospital,Pathumthani,Thailand, ³Ophthalmology,Thammasat University,Pathumthani,Thailand;Ophthalmology,Chulabhorn International College of Medicine,Pathumthani,Thailand

Purpose

To evaluate the interdevice variability among 4 different units of SCHWIND ATOS used by a single surgeon at four different locations by comparing the 1-year refractive and visual outcomes of SmartSight KLEx procedures.

Setting

EYE+LASER in 4 private practices: Warsaw, Vienna, Zürich, Krakow
Victor Derhartunian, MD

Methods

Retrospective observational analysis of the 1-year follow-up including 442 bilateral eyes (226 eyes from Warsaw, 114 eyes from Vienna, 72 eyes from Zurich and 30 eyes from Krakow) from 221 patients, with a mean age of 32±7 years (range: 18–50 years), who underwent lenticule extraction treatments using the SmartSight method with the SCHWIND ATOS femtosecond laser. Uncorrected and corrected distance visual acuity (UDVA, CDVA), and refractive outcomes (spherical equivalent, astigmatism) were compared among centers using ANOVA and X2 statistical analyses.

Results

Overall, mean preop SEQ was -4.25±1.73 D [range -1.25 to -9.38D] (-4.40±1.69 D in Warsaw, -4.43±1.82 D in Vienna, -3.63±1.50 D in Zurich and -3.88±1.84D in Krakow, ANOVA and X2 p-value <.01 with Zürich including lower and narrower values). ANOVA tests demonstrated a higher residual myopia in Warsaw (postop SEq -0.25±0.33 D vs -0.1±0.30 D), no relevant differences in postop UDVA vs preop CDVA (-0.3±0.8lines) or change in CDVA (+0.2±0.6lines) were found. X2 tests suggest no differences for refractive outcomes were found among the 4 systems; whereas visual outcomes were identical for all 3 centres, but Zürich.

Conclusions

While all four lasers effectively reduced preoperative refraction and improved visual acuity, Zürich showed statistically significant differences in (visual) outcomes. These differences were below any clinical relevance. The other three ATOS units did not show any statistically significant differences (although for one of them, the lower number of evaluated patients reduces the statistical power of its comparison). Data collection suggests differences in visual outcomes may be affected by the different optometrists and different circumstances across different locations.