CONTRIBUTION OF REFRACTION MEASUREMENT TO VARIANCE OF REFRACTIVE OUTCOMES AFTER REFRACTIVE LENTICULE EXTRACTION
Published 2024 - 28th ESCRS Winter Meeting
Reference: FP16 | Type: Submission | DOI: 10.82333/29f2-xn12
Authors: Suphi Taneri* 1 , Samuel Arba-Mosquera 2 , Anika Förster 3 , H. Burkhard Dick 4
1Center for Refractive Surgery,Eye Center at St. Francis-Hospital, Muenster,Muenster,Germany;Ruhr-University Bochum,Bochum,Germany, 2SCHWIND eye-tech solutions,Kleinostheim,Germany, 3Center for Refractive Surgery,Eye Center at St. Francis-Hospital, Muenster,Muenster,Germany, 4Ruhr-University Bochum,Bochum,Germany
Purpose
Outcomes of lenticule extraction (LE) are influenced by tolerance of laser application, wound healing, and refraction measurement. We wanted to evaluate variance of manifest refraction measurement and to evaluate its contribution to the variance of refractive outcomes after LE in the same cohort.
Setting
Center for Refractive Surgery, Eye Department at St. Francis Hospital Muenster, Germany
Methods
Retrospective study.
Consecutive patients attending at least 3 preoperative refractions before undergoing LE were included. Soft contact lenses were paused for more than 2 weeks and rigid ones for more than 4 weeks before the initial evaluation. Patients were educated about the importance of ocular surface optimization and a therapy initiated or continued, if deemed necessary. 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. After LE, the variance of postoperative outcomes was compared to the inherent 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 0.69 D for sphere, 0.60 D for cylinder, and 0.59 D for SE, respectively. The SD for corrected distance visual acuity (CDVA) was 0.07 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 LE (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
Isolated repeatability of LE was better than the reproducibility of manifest refraction. Improving the accuracy and precision of (manifest) refraction preoperatively seems to be the most important factor to increase the predictability of LE. The uncertainty of refraction measurement was by far the most important factor for variation of LE outcomes. Pausing soft contact lenses for 2 weeks and rigid ones for 4 weeks seems not sufficient in a significant portion of refractive patients. Moreover, relying on refraction measurements taken at only one day seems less than optimal in order to achieve maximum predictability.