Refractive lenticule extraction (ReLEx flex) and wavefront-optimized Femto-LASIK: comparison of contrast sensitivity and high-order aberrations at 1 year
To compare 1-year results of the refractive lenticule extraction (ReLEx) flex technique performed as a commercial bilateral simultaneous procedure to a matched group of wavefront-optimized Femto-Lasik for correction of myopia and astigmatism with emphasis on contrast sensitivity and high-order aberrations (HOA).
In this retrospective study 44 eyes of 22 patients with spherical equivalent (SE) of −5.13 D who underwent ReLEx were matched to 50 eyes of 25 patients with SE of −5.42 D treated by wavefront-optimized Femto-Lasik. We used Carl Zeiss Meditec (CZM) VisuMax® femtosecond laser system with a 200 kHz repetition rate. In addition, for Femto-LASIK, MEL 80 Excimer Laser (CZM) with aspheric ablation profiles was used for ablation.
At 1 year, the mean SE in the ReLEx group was −0.23 ± 0.35 D and in the Femto-LASIK group −0.15 ± 0.27 D. The mesopic contrast sensitivity of ReLEx treated eyes at 12 and 18 cpd improved from 1.49 and 0.99 to 1.54 and 1.1 respectively. In the Femto-LASIK group the numbers were pre-op 1.51 and 1.03, and after 1 year 1.54 and 1.06. The high-order aberrations (HOA) after ReLEx changed from 0.15 to 0.23 μm, and after Femto-LASIK from 0.175 to 0.320 μm (p = 0.0023).
At 1 year, wavefront-optimized Femto-LASIK produced similar refractive outcomes to ReLEx® flex with better, but non-significant accuracy. In contrast, ReLEx® flex showed significantly less induction of HOA and better mesopic mid-term contrast sensitivity then the wavefront-optimized Femto-LASIK.
KeywordsReLEx FLEx Femto-LASIK Contrast sensitivity High order aberrations Femtosecond lenticule extraction Refractive lenticule extraction Corneal refractive surgery Myopia Astigmatism