VARIANCE OF KERATOREFRACTIVE LENTICULE EXTRACTION IS DETERMINED BY VARIANCE OF PRE-OPERATIVE MANIFEST REFRACTION MEASUREMENT
Published 2025 - 29th ESCRS Winter Meeting
Reference: PO002 | Type: Presented Poster & Poster | DOI: 10.82333/xe9z-9t71
Authors: Suphi Taneri* 1 , Samuel Arba-Mosquera 2 , Anika Förster 3 , H. Burkhard Dick 4
1Center for Refractive Surgery,Eye center of St. Francis Hospital,Muenster,Germany;Ruhr-University,Bochum,Germany, 2SCHWIND eye-tech solutions,Kleinostheim,Germany, 3Center for Refractive Surgery,Eye center of St. Francis Hospital,Muenster,Germany, 4Ruhr-University,Bochum,Germany
Purpose
To compare variance of manifest refraction (MR) measurement and variance of refractive outcomes after keratorefractive lenticule extraction (KLEx) in the same cohort.
Setting
Center for Refractive Surgery, Eye Department at St. Francis Hospital
Methods
Retrospective study of consecutive patients attending at least 3 preoperative refractions before undergoing KLEx. Soft contact lenses were paused for more than 2 weeks and rigid ones for more than 4 weeks before the initial evaluation. All manifest refractions were performed according to a standard protocol by 4 experienced optometrists. Additionally, automated refraction, spectacles prescription, wavefront refraction and tomography/topography were also considered when determining the treatment refraction. Variance of postoperative outcomes was compared to variance of the manifest refraction measurement.
Results
The difference in manifest refractions of 153 eyes between the first and last preoperative visit showed a mean pairwise absolute difference of 0.22±0.22 diopter (D) (range 0 to 1.25 D) in spherical equivalent (SE). The 95% limit of agreement (LoA) was within 0.73 D for sphere, 0.59 D for cylinder, and 0.61 D for SE, respectively. The SD for corrected distance visual acuity (CDVA) was 0.06 logMAR and the 95% LoA was within 1.3 Snellen lines. In contrast, differences between reproducibility of the 2 last preoperative manifest refractions and the variance of postoperative outcomes after KLEx (i. e. the isolated repeatability of corneal lenticule extraction) was SD of 0.13 D for sphere, cylinder, and SE, and 11 degrees in axis, respectively.
Conclusion
Predictability of KLEx was equal to variance of refraction measurement. Isolated repeatability of the laser treatment was better than the reproducibility of MR. Thus, we have shown for the first time, that precision of KLEx has reached such a level today that further improvement is limited by MR measurements.