Comparative Analysis of the Efficiency, Safety, Predictability of Wavefront-Guided and Conventional FemtoLASIK Procedures in Low to Moderate Myopia

Purpose : to evaluate the effectiveness, safety, and predictability of the wavefront-guided FemtoLASIK using the Platoscan computer program and data from the KR-1W aberrometer, in comparison with the conventional algorithm FemtoLASIK in patients with low to moderate myopia. Patients and methods . There were 62 eyes of 62 patients with low to moderate myopia who had undergone FemtoLASIK procedure using an excimer laser ‘Microscan Visum” (Russia) and a femtosecond laser Femto LDV Z6 (Switzerland) in the study. In the “Wavefront” group which included 31 eyes with a mean spherical equivalent (SE) -=3,32 ± 1,23 D (M ± SD) was performed a wavefront-guided Femtosecond LASIK using aberrometer KR-1W (Japan) and a program for calculating the operation’s parameters “Platoscan” (Russia). “Standard” group included 31 eyes with an average SE –3.51 ± 1.21 D (M ± SD), who received the conventional FemtoLASIK. The “Wavefront” and “Standard” groups were comparable in terms of pre-operative data (age, sex, corneal curvature, central thickness of the cornea, sphere, cylinder, SE) (p > 0.05). All patients underwent complete ophthalmological examination before refractive laser surgery, and also patients were examined on the 1st day and 1 month after FemtoLASIK. Results . One month postoperatively, in the “Wavefront” group the UDVA 1.0 or better (20/20 or better by Snellen) was achieved in 93.5%, in the “Standard” group — in 96,8% (p > 0.05). There wasn’t observed a loss of the CDVA lines in both groups. In the “Wavefront” group, gain of one or more lines of the CDVA was in 38.7%, in the “Standard” group — in 12.9% (p = 0.04, Fisher’s exact test). In the “Wavefront” group the predictability of targeted refraction within ±0.5 D was in 93.5%, within ±1.0 D — in 100%, in the “Standard” group — in 90,3 and 100%, respectively (p > 0.05). The efficiency index in the “Wavefront” group was 1.00 (1.00; 1.20) (Me (Q25; Q75)), in the “Standard” group — 1.00 (1.00; 1,00) (Me (Q25; Q75)) (p > 0.05). The safety index in the “Wavefront” group was 1.00 (1.00; 1.20) (Me (Q25; Q75)), in the “Standard” group — 1.00 (1.00; 1,00) (Me (Q25; Q75)) (p > 0.05). Conclusions . The FemtoLASIK procedure, performed according to the conventional and wavefront-guided algorithms using the “Platoscan” computer program and data from the KR-1W aberrometer, is an effective, safe and predictable method for correcting low to moderate myopia, there is no statistically significant difference between two algorithms (p > 0.05).