Comparative evaluation of the FemtoLASIK visual outcomes in low to moderate myopia using different excimer lasers

Purpose. To evaluate visual and refractive results of FemtoLASIK using the WaveLight EX 500 and Microscan Visum excimer laser systems in patients with low to moderate myopia.Material and methods. This study was performed in 62 eyes of 62 patients with low to moderate myopia operated according to the FemtoLASIK technique using the different excimer lasers WaveLight EX 500 (USA) and Microscan Visum (Russia). All patients underwent a complete ophthalmological examination before the laser refractive surgery, on the 1st day and 1 month after the FemtoLASIK. The results are presented as Me (Q25; Q75).Results. Postoperatively the uncorrected distance visual acuity (UDVA) increased from 0.05 (0.04; 0.10) to 1.00 (1.00; 1.00) (p<0.000) in the ≪WaveLight EX 500≫ group and from 0.06 (0.04; 0.10) to 1.00 (1.00; 1.20) (p<0.000) in the ≪Microscan Visum 500≫ group. The spherical equivalent (SE) of refraction decreased from -3.875 (-4.50; -3.00) to 0.00 (0.00; 0.00) (p<0.000) in the ≪WaveLight EX 500≫ group and from -3.375 (-4.25; -2.75) to 0.00 (0.00; 0.00) (p<0.000) in the ≪Microscan Visum 500≫ group. The efficiency index in the ≪WaveLight EX 500≫ group was 1.00 (1.00; 1.00), in the ≪Microscan Visum 500≫ group – 1.00 (1.00; 1.00) (p>0.05), the safety index was 1.00 (1.00; 1.00) and 1.00 (1.00; 1.00), respectively (p>0.05). Visual and refractive results showed no statistically significant difference between the two groups (p>0.05). The ablation depth was higher in the ≪Microscan Visum≫ group compared with the ≪WaveLight EX 500≫ group.Conclusions. 1. The conventional FemtoLASIK procedure using the WaveLight EX 500 and Microscan Visum excimer lasers, is an effective and safe method for low to moderate myopia correction. There is no statistically significant difference between two algorithms (p>0.05). 2. It is necessary to improve the standard ablation algorithm on the Microscan Visum excimer laser platform to reduce the ablation depth