S.B. IZMAYLOVA ¹, A.S. ZAVYALOV², K.V. BURDEL¹, B.S. SHAVKUTA³, M.M. KONOVALOVA¹, A.V. SHATSKIH¹, Kh.D. TONAEVA¹, I.N. SHORMAZ¹

¹S. Fyodorov Eye Microsurgery Federal State Institution, 59а Beskudnikovsky Blvd, Moscow, Russian Federation, 127486

²Optosystems Ltd., 2 Promyshlennaya Str., Moscow, Troitsk, Russian Federation, 142191

³Institute of Photon Technologies, Federal Scientific and Research Center «Crystallography and Photonics» of the Russian Academy of Sciences, 9 Leninskiy Ave., Moscow, Russian Federation, 119333

Izmaylova S.B. ― PhD (medicine), Head of the Division of Transplantation and Opto-Restorative Surgery of anterior segment of an eyeball, tel. (499) 488-84-69, е-mail: lana-dok@mail.ru

Zavyalov A.S. ― Chief of the Femtosecond Medical Laser Group, tel. (499) 488-84-69, e-mail: zavyalov@optosystems.ru

Burdel K.V. ― resident, e-mail: konstatinburdel@gmail.com

Shavkuta B.S. ― junior researcher, tel. (499) 135-63-11, e-mail: b.shavkuta@gmail.com

Konovalova M.M. ― resident, e-mail: mariakonovalova11@rumbler.ru

Shatskih A.V. ― PhD (medicine), Head of the Laboratory of Eye Pathology and Histology, Pathologoanatomist, e-mail: avsatik@yandex.ru

Tonaeva Kh.D. ― PhD (medicine), Head of the Eye Tissue Bank, tel. (499) 906-50-01, e-mail: onxd15@gmail.com

Shormaz I.N. ― Ophthalmologist, tel. (499) 906-50-01, e-mail: irishor@yandex.ru

The aim of the study is to evaluate the results of femtosecond radial keratotomy with the help of the domestic laser «Femto Visum» in the ex vivo experiment. The technical feasibility of carrying out this procedure and the quality of its implementation were estimated. The specialists of Optosistemy LLC together with Federal State Autonomous Institution «Interbranch scientific and technical complex «Eye Microsurgery» named after Acad. S.N. Fedorov» developed software that has no analogues in the world for carrying out femtosecond keratotomy on the domestic laser «Femto Visum». In the cadaver eyes, eight radial incisions are made in the annular zone of the cornea with an external diameter of 9.0 to 9.5 mm, an internal diameter of 4.5 to 5.0 mm. The depth of the cuts was 85% of the minimum value of the pachymetry, the indentation from the anterior surface of the cornea changed depending on the cutting or not crossing the Bowman’s membrane. In the following, a histological examination of the cornea of the experimental eyes was carried out. Based on the research findings, successful implementation of 8 radial symmetrical equidistant and identical along the length of the cuts was revealed. The central zone of the cornea remained intact. Visually the sections were symmetrical, their thickness did not differ between themselves and within each individual cut.

According to the results of histology, the changes characteristic for the influence of a femtosecond laser on the cornea were revealed. The stroma is completely cut through in a given interval with the formation of an intrastromal cavity, Descemet’s and Bowman’s membranes are not cut through in the experiment.

The developed technique of femtosecond laser keratotomy on the domestic femtosecond laser «Femto Visum» was successfully modeled in the ex vivo experiment. With the help of specially developed software, the precision cutting in the anterior corneal layers is possible, which allows preserving the integrity of the epithelial layer with the crossing of the Bowman’s membrane. This will allow obtaining results without the associated complications that are typical for manual techniques.

Key words: radial keratotomy, femtosecond laser, keratoconus.

(For citation: Izmaylova S.B., Zavyalov A.S., Burdel K.V., Shavkuta B.S., Konovalova M.M., Shatskih A.V., Tonaeva Kh.D., Shormaz I.N. Radial keratotomy with femtosecond laser tracking using the domestic laser «Femto Visum» as a method of treatment of progressive keratoconus. Experimental study ex vivo. Practical Medicine. 2018)

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