Clinical and functional outcomes of correcting low to moderate myopia with FemtoLASIK performed with Russian and Swiss femtolaser platforms

Abstract

To compare the effectiveness, safety, predictability and stability of FemtoLASIK procedure in low to moderate myopia using Femto Visum and Femto LDV Z6 femtosecond laser platforms and to evaluate the effect of these procedures on corneal higher-order aberrations. Russian femtolaser platform (1 MHz) was used to form the corneal flap in the main group consisting of 98 patients (98 eyes) with mean spherical equivalent (SE) of -3.73±1.42 D. Swiss femtolaser platform (5 MHz) was used in the control group (94 patients, 94 eyes; mean SE -3.81±1.44 D). Excimer laser ablation was performed using the Russian platform (500 Hz) in both groups. All patients underwent complete ophthalmological examination. The follow-up period was 12 months. Twelve month postoperatively, in the '1 MHz' group uncorrected visual acuity (UCVA) of 1.0 or better was achieved in 91.8% of patients, and in the '5 MHz' group - in 90.4% (p>0.05). There were no registered losses of 2 or more lines of best-corrected visual acuity (BCVA) in either group. In the '1 MHz' group, predictability of targeted refraction within ±0.5 D was achieved in 91.8% of patients, within ±1.0 D - in 99.0%; in the '5 MHz' group - in 91.5% and 98.9% of patients, respectively (p>0.05). Root-mean-square (RMS) deviation of corneal higher-order aberrations in the 6-mm optical zone was increased by 0.072 μm (by 1.21 times) and by 0.077 μm (by 1.22 times) in the '1 MHz' and '5 MHz' groups (p>0.05), respectively. The FemtoLASIK procedures performed using Russian (1 MHz) and Swiss (5 MHz) femtosecond laser platforms are effective, safe, predictable, have stable postoperative visual and refractive outcomes, and lead to increase in RMS of corneal higher-order aberrations using both platforms in patients with low to moderate myopia. There were no statistically significant differences between the two femtolaser platforms (p>0.05) for all examined parameters.