The Impact of Learning Curve on Flap Thickness Outcome in Femtosecond Laser-assisted Laser In Situ Keratomileusis Performed with New LenSx Dual Platform

Abstract

Background: To evaluate the effect of learning curve on flap thickness outcome in femtosecond (FS) laser assisted LASIK operation for myopia performed with recently introduced LenSx dual platform using curved applanation cone. Methods: Seventy eyes of 36 patients with myopia or myopic astigmatism operated with FS laser-assisted LASIK with recently introduced LenSx dual platform were evaluated in this retrospective study. Operations were divided into two groups including first-20 operations (20 eyes of 10 patients) and next-50 operations (50 eyes of 26 patients). Data on patient demographics, preoperative and postoperative keratometric and aberrometric parameters and flap thickness related outcome including mean central flap thickness (MCFT), mean total flap thickness (MTFT), intra-FT range and flap thickness homogeneity (FTH) were compared in study groups. Results: Except for significantly lower preoperative steepest keratometry (K2) values in the next-50 operations vs. first-20 operations (p=0.033), no significant difference was noted between study groups in terms of preoperative and postoperative parameters. When compared to first-20 operations, next-50 operations were associated with significantly higher values for MCFT (median 123 vs. 114 µm, p=0.007) and MTFT (median 123 vs. 113 µm, p=0.015), whereas significantly lower intra-FT range (median 4.0 vs. 4.5 µm, p=0.003). Conclusions:In conclusion, our findings related to FS laser assisted LASIK surgery for myopia with new LenSx dual platform using curved applanation cone revealed significant impact of learning curve on the corneal flap thickness outcome in terms of closer flap thickness to the intended value and lower intra-flap range.

Corneal Lenticule Creation Using a New Solid-State Femtosecond Laser Measured by Spectral Domain OCT in a Porcine Eye Model

“…Additionally, it remains to discuss if the initially higher deviation of measurements in group 1 is due to a learning curve in the first treated and measured eyes, which is reported as well by Asena and Donmez, 25 who report a learning curve in terms of flap thickness in fs-LASIK for their first 20 eyes of the trial. Still, one has to discuss if a deviation from intended measures is clinically relevant as long as there is no downside to the precision in terms of treated SE.…”