Vector Analysis Of High Astigmatic Correction In Smile: A Comparative Study Of Visumax 500 And Visumax 800
Published 2025 - 43rd Congress of the ESCRS
Reference: FP26.07 | Type: Free paper | DOI: 10.82333/xa99-9681
Authors: Maher Alsusa* 1 , Poonam Sharma 2 , Shakeel Ahmad 2 , Zoe Smith 2 , Emma Tutchings 2 , Sam Evans 3 , Elizabeth Wilkinson 4 , Harry Roberts 5
1Medical School,University of Exeter,Exeter,United Kingdom, 2West of England Eye Unit,Royal Devon University Healthcare NHS Foundation Trust,Exeter,United Kingdom, 3Lutra Health Ltd.,Pencoed,United Kingdom, 4West of England Eye Unit,Royal Devon University Healthcare NHS Foundation Trust,Exeter,United Kingdom;NHS London,Getting It Right First Time (GIRFT),London,United Kingdom, 5West of England Eye Unit,Royal Devon University Healthcare NHS Foundation Trust,Exeter,United Kingdom;Faculty of Health and Life Sciences,University of Exeter,Exeter,United Kingdom
Purpose
To compare the astigmatism correction outcomes of small incision lenticule extraction (SMILE) using the VisuMax 500 and VisuMax 800 in patients with high astigmatism, utilizing vector analysis.
Setting
Onnuri Smile Eye Clinic, Seoul, South Korea
Methods
This retrospective, comparative study included patients with high astigmatism (≥3.0 D) who underwent SMILE with VisuMax 500 (SMILE group) or VisuMax 800 (SMILE Pro group). The cyclotorsion adjustment feature of the VisuMax 800 was not utilized, and preoperative corneal marking was not performed in either group.
Results
A total of 203 eyes in the SMILE group and 186 eyes in the SMILE Pro group were included. At 3 months postoperatively, residual astigmatism was -0.57 ± 0.31 D and -0.51 ± 0.28 in the SMILE and SMILE Pro groups, respectively (P = 0.029). The vector analysis showed significantly better astigmatism correction outcomes in the SMILE Pro group, with surgically induced astigmatism (P = 0.007), difference vector (P = 0.029), correction index (P = 0.006), index of success (P = 0.025), magnitude of error (P = 0.011), flattening effect (P = 0.003), and flattening index (P = 0.004).
Conclusions
SMILE using the VisuMax 800 provided significantly superior astigmatism correction compared to SMILE with the VisuMax 500 in patients with high astigmatism. These results were achieved without utilizing the cyclotorsion adjustment feature, highlighting the importance of the VisuMax 800's faster laser speed and advanced eye-tracking system.