E.G. POGODINA¹, I.A. MUSHKOVA², A.N. KARIMOVA², A.D. SEMENOV², V.G. MOVSHEV³

¹Orenburg branch of the S. Fyodorov Eye Microsurgery Federal State Institution, 17 Salmyshskaya Str., Orenburg, Russian Federation, 460047

²The S. Fyodorov Eye Microsurgery Federal State Institution, 59a Beskudnikovsky blvrd, Moscow, Russian Federation, 127486

³«Optosistemy» LLC, 1-A Promyshlennaya Str., the Moscow Region, Troitsk, Russian Federation, 142191

Pogodina E.G. ― Doctor of the Laser Surgery Department, tel. +7-903-367-17-78, e-mail: elenapogodina56@yandex.ru
Mushkova I.A― eye surgeon, D. Med. Sc., Head of the Laser Refractive Surgery Department, tel. +7-903-150-21-33, e-mail: i.a.mushkova@yandex.ru

Karimova A. N. ― eye surgeon, Cand. Med. Sc., Researcher of the Laser Refractive Surgery Department, tel. +7-903-106-51-41, e-mail: adelya.k.n@mail.ru

Semenov A. D. ― D. Med. Sc., Professor, Corresponding Member of the Russian Academy of Sciences, Chief Scientific Consultant of the Laser Refractive Surgery Department, tel. +7-985-767-23-82, e-mail: nauka@mntk.ru

Movshev V.G. ― Cand. Phys. and Tech. Sc., Head of Medical Lasers in the Thematic Design Department №7, tel. (495) 851-08-95/0211, e-mail: vmovshev@yahoo.com

The results of the analysis of visual acuity, functional optical zone (FOZ), changes in pre- and postoperative conic constants in patients with myopia, who have undergone excimer laser surgery at Microscan-PIC and WaveLight EX500 using aspherical algorithm of exposure, are presented in the article. For the analysis, data from 23 eyes of 12 patients with myopia with a mean spherical equivalent of -4.34 Dpt +/- 1.54, operated at «Microscan PIC», and data from 19 eyes of 10 patients with a mean spherical equivalent of -3.83 Dpt +/- 1.96, operated at WaveLight EX500, were used. The technique described by Camellin M. and Arba Mosquera S. [10] was used for calculation of FOZ in the study. By using «Microscan-PIC» device was determined the tendency to decrease in FOZ at transfer from a weak to a high degree of myopia using aspherical ablation algorithm with a given conic constant, growth of multifocality with an increase of degree of corrected myopia, which is a drawback of the existing aspherical algorithm of this device and needs its optimization. At WaveLight EX500 device we determined the dependence of the increase of FOZ on the increase in the spherical equivalent when performing aspheric operations using the wavefront optimization (WFO) algorithm and an algorithm that is personalized in Q-factor. The revealed cases of excessive multifocality, the expressed dependence of Q-shift from preoperative keratometry in the correction of weak degree of myopia at WaveLight EX500 require an optimization of the approach to the choice of the surgery algorithm.

Key words: asphericity, conic constant, functional optical zone.

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