High-speed photorefractive keratectomy with femtosecond ultraviolet pulses.
Femtosecond near-infrared lasers are widely used for a number of ophthalmic procedures, with flap cutting in the laser-assisted in situ keratomileusis (LASIK) surgery being the most frequent one. At the same time, lasers of this type, equipped with harmonic generators, have been shown to deliver enough ultraviolet (UV) power for the second stage of the LASIK procedure, the stromal ablation. However, the speed of the ablation reported so far was well below the currently accepted standards. Our purpose was to perform high-speed photorefractive keratectomy (PRK) with femtosecond UV pulses in rabbits and to evaluate its predictability, reproducibility and healing response. The laser source delivered femtosecond 206 nm pulses with a repetition rate of 50 kHz and an average power of 400 mW. Transepithelial PRK was performed using two different ablation protocols, to a total depth of 110 and 150 μm. The surface temperature was monitored during ablation; haze dynamics and histological samples were evaluated to assess outcomes of the PRK procedure. For comparison, analogous excimer ablation was performed. Increase of the ablation speed up to 1.6 s/diopter for a 6 mm optical zone using femtosecond UV pulses did not significantly impact the healing process.
Akiu Gydytoju Praktika (private ophthalmological practice), V. Grybo 17-127, Vilnius 10318, Lithuania.
Egle
E
Danieliene
Light Conversion Ltd., Keramiku 2, Vilnius 10233, LithuaniacVilnius University, Department of Quantum Electronics, Faculty of Physics, Sauletekio Street 10, Vilnius 10223, Lithuania.
Egle
E
Gabryte
Light Conversion Ltd., Keramiku 2, Vilnius 10233, LithuaniacVilnius University, Department of Quantum Electronics, Faculty of Physics, Sauletekio Street 10, Vilnius 10223, Lithuania.
Mikas
M
Vengris
Vilnius University, Department of Biochemistry and Biophysics, Faculty of Natural Sciences, M. K. Ciurlionio Street 21/27, Vilnius 03101, Lithuania.
Osvaldas
O
Ruksenas
Akiu Lazerines Chirurgijos Centras Ltd., Krokuvos 11, Vilnius 09314, Lithuania.
Algimantas
A
Gutauskas
Vilnius University, Department of Botany and Genetics, Faculty of Natural Sciences, M. K. Ciurlionio Street 21/27, Vilnius 03101, Lithuania.
Vaidotas
V
Morkunas
Light Conversion Ltd., Keramiku 2, Vilnius 10233, Lithuania.
Romualdas
R
Danielius
D000818:Animals; D002138:Calibration; D003315:Cornea / Q000528:radiation effects; D005123:Eye / Q000528:radiation effects; D020731:Keratomileusis, Laser In Situ; D007834:Lasers; D055095:Optics and Photonics; D018903:Photorefractive Keratectomy / Q000295:instrumentation* / Q000379:methods*; D011183:Postoperative Complications; D011817:Rabbits; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays; D014945:Wound Healing