Implantable collamer lens and femtosecond laser for myopia: comparison using an adaptive optics visual simulator Lente implantável de collamer e laser de femtosegundo para miopia: comparação usando um simulador visual de óptica adaptativa

The femtosecond laser (FS) is the most interesting technical de velopment in laser refractive surgery during the last few years. This technique was developed to create flaps for laser in situ keratomileusis (LASIK). The FS is a focusable infrared (1053 nm) laser that uses ultrafast pulses in the 100-femtosecond (100 x 10 second) range. The laser delivers closely spaced spots that can be focused at a preset depth to photodisrupt tissue within the corneal stroma, while causing minimal inflammation and collateral tissue damage. In the recent meta-analysis by Zhang et al. that compared femtosecond LASIK (F-LASIK) with mechanical microkeratome LASIK for myopia, no ABSTRACT Purpose: To compare optical and visual quality of implantable collamer lens (ICL) implantation and femtosecond laser in situ keratomileusis (F-LASIK) for myopia. Methods: The CRX1 adaptive optics visual simulator (Imagine Eyes, Orsay, France) was used to simulate the wavefront aberration pattern after the two surgical procedures for -3-diopter (D) and -6-D myopia. Visual acuity at different contrasts and contrast sensitivities at 10, 20, and 25 cycles/degree (cpd) were measured for 3-mm and 5-mm pupils. The modulation transfer function (MTF) and point spread function (PSF) were calculated for 5-mm pupils. Results: F-LASIK MTF was worse than ICL MTF, which was close to diffraction-limited MTF. ICL cases showed less spread out of PSF than F-LASIK cases. ICL cases showed better visual acuity values than F-LASIK cases for all pupils, contrasts, and myopic treatments (p<0.05). No statistically significant differences were found in contrast sensitivities between ICL and F-LASIK cases with -3-D myopia for both pupils for all evaluated spatial frequencies (p>0.05). For -6-D myopia, however, statistically significant differences in contrast sensitivities were found for both pupils for all evaluated spatial frequencies (p<0.05). Contrast sensitivities were better after ICL implantation than after F-LASIK. Conclusions: ICL implantation and F-LASIK provide good optical and visual quality, although the former provides better outcomes of MTF, PSF, visual acuity, and contrast sensitivity, especially for cases with large refractive errors and pupil sizes. These outcomes are related to the F-LASIK producing larger high-order aberrations.