The first clinical and functional results of mixed astigmatism correction with femtosecond lenticular technology

Background. Mixed astigmatism is one of the most difficult refractive errors to correct. Traditional excimer laser techniques are associated with the risk of biomechanical complications due to the formation of a corneal flap. Lenticular technology offers a minimally invasive alternative, but its application in the case of mixed astigmatism is not well-studied and requires the development of specialized surgical approaches.

The aim. To evaluate the effectiveness of early clinical and functional results in the correction of mixed astigmatism using femtosecond lenticular technology.

Methods and materials. The study included 10 patients (15 eyes) aged 32.4 ± 6.13 years with mixed astigmatism. Following a comprehensive preoperative examination, all patients underwent refractive lenticule extraction using the SMILE method using a VisuMax™ 500 kHz femtosecond laser (Carl Zeiss Meditec AG) with preliminary calculation of lenticule parameters using the developed technology. Postoperative monitoring was performed on the 1st day, 1 week, and 1 month.

Results. After one month, the uncorrected visual acuity was 0.90 ± 0.11, corresponding to the preoperative best-corrected visual acuity (0.90 ± 0.18). The spherical equivalent stabilized at 0.06 ± 0.45 D. The cylindrical component decreased from -2.77 ± 0.79 D to -0.22 ±0.47 D. Keratometry readings decreased from 42.59 ±1.56 D to 40.80 ±1.08 D. Central corneal thickness decreased to 499.53 ± 34.27 µm (baseline: 555.87 ± 33.02 µm) while maintaining residual stroma at 376.27 ± 32.50 µm. No additional correction or complications were required.

Conclusion. The developed technology for correcting mixed astigmatism based on refractive parameter transposition in lenticular surgery is effective and safe – high visual function was achieved in the early postoperative period with minimal risk of complications and preserved biomechanical stability of the cornea, confirming the potential for further research.

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