Early Clinical and Functional Results of Mixed Astigmatism Correction Depending on the Degree with the High-frequency Excimer Laser Schwind Amaris 1050RS

Purpose. To conduct a prospective comparative study of the early results of mixed astigmatism’s correction by the Femto-LASIK method using the excimer laser Schwind Amaris 1050RS depending on the degree of astigmatism Patients and methods. This singlecenter, prospective study included 281 patients with mixed astigmatism, mean age 28.96 ± 7.92 years. Group I consisted of patients with astigmatism ≤3.0D; Group II — > 3.0D on the principle of one patient — one eye. All patients underwent laser correction with the Femto-LASIK method. 
Results. Three months after Femto-LASIK, the average uncorrected visual acuity (UCVA) in patients of the first study group was comparable with the preoperative value of best corrected visual acuity (BCVA) — 0.93 ± 0.11 and 0.91 ± 0.13, respectively (p = 0.5). In group II, it was equal to 0.73 ± 0.20 and statistically significantly (p = 0.01) exceeded the preoperative level of 0.68 ± 0.18. The efficiency ratio was 88.1% and 84.3% in groups I and II respectively. A decrease in BCVA by 0.2 was noted in 0.8% (1 eye) in group I and in 3.3% of cases (5 eyes) in group II, the safety ratio in group I was 99.2%, in group II — 96.7%. The spherical equivalent within ±0.50D was achieved in 89 eyes (70.1%) in group I and 79 eyes (51.3%) in group II, ±1.0D in 98.4% of cases (125 eyes) and 96.7% (149 eyes) in groups I and II respectively. The integral index of the CI value in the vector analysis according to Alpins N. in group I was 0.89 ± 0.10, in group II — 0.94 ± 0.05. After correction, patients of the studied groups showed an increase in HOA RMS and spherical aberration, as well as a significant decrease in the RMS value of astigmatism, all data were statistically significant (p < 0.05). In the second group, negative dynamics in the coma level were also noted (p < 0.05). 
Conclusion. The conducted prospective comparative study of early results of mixed astigmatism correction by Femto-LASIK using the Schwind Amaris 1050RS with cyclotorsion control, high pulse repetition rate and optimized aspheric ablation profile confirmed the safety, effectiveness and predictability of correction of this type of astigmatism regardless of its degree.

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