| Abstract [eng] |
Refractive errors negatively influence the quality of human life. The most popular surgical procedure for treatment of refractive errors is the laser-assisted in situ keratomileusis. The main goal of this work is to explore the possibility to replace two different laser systems (UV nanosecond and nIR femtosecond), that are currently used for the refractive corneal surgery, with a single Yb:KGW femtosecond nIR laser equipped with the UV harmonic generator. We have demonstrated that: (1) the rate, at which the radiation of the high repetition rate femtosecond UV harmonic generator can be manipulated, is limited by the absorption of UV pulses in nonlinear optical crystals; this rate can be increased by implementing the adaptive manipulation of the tuning angle of the nonlinear crystal; (2) using the fundamental nIR radiation of the Yb:KGW solid-state laser, the corneal LASIK flap is created precisely and reproducibly; the duration of the procedure is comparable to the commercial laser systems; (3) performance of the femtosecond Yb:KGW solid-state system is comparable to the conventional excimer ArF laser systems with respect to the ablation speed and the surface quality of the corneal stroma; (4) the cytotoxic and genotoxic impact of the UV radiation on cells depends on the wavelength of the UV source rather than on the pulse duration. The genotoxic impact of the femtosecond 205 nm pulses does not exceed the one of the nanosecond UV pulses, that are used for ophthalmic procedures; (5) most of modern ophthalmic laser procedures can be performed using the single solid-state Yb:KGW femtosecond laser system equipped with the fifth-harmonic generator. |
