Aim — to comparatively analyze corneal aberrations after intrastromal corneal segments (ICS) and MyoRing implantation using femtosecond laser in patients with stage II-III keratoconus (KC) by Pentacam examination. Material and methods. We have operated on 135 patients (145 eyes) with stage II or III KC. Depending on surgical technique, all patients were divided into two groups. Group I consisted of patients with KC, who received optimized femtosecond laser-assisted MyoRing implantation, group II — of those, who received femtosecond laser-assisted ICS implantation. Depending on the stage of the disease, each group was further divided into two subgroups, for stage II and stage III KC, respectively. Before and after surgery, all patients underwent visometry, biomicroscopy, corneal topography, and corneal aberrations measurement under photopic and mesopic conditions on Pentacam. The follow-up period averaged 30 months (from 6 to 34 months). Results. In both groups corneal aberrations significantly decreased after surgery, which was confirmed by an improvement in parameters of refraction and keratometry readings. Conclusion. Implantation of intrastromal MyoRings leads to a greater reduction in the total corneal aberration, higher-order aberrations under photopic and mesopic conditions, and spherical aberration under photopic conditions as compared to ICS in patients with stage III KC; a comparable reduction in the total corneal, higher-order, and spherical aberrations under photopic conditions as compared to ICS in patients with stage II KC; a comparable increase in spherical aberration under mesopic conditions as compared to ICS in patients with stage III KC.