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.

Over the last decade, corneal collagen cross-linking (CXL) has become a conventional treatment method for progressive keratoconus. Laboratory studies have shown that CXL increases the diameter of collagen fibers and also the number of intra- and interfibrillar cross-links, thus, increasing biomechanical strength of the irradiated cornea. As confirmed by a series of clinical and randomized controlled trials, CXL is able to slow down and, perhaps, to stop the progression of keratoconus. In most post-CXL patients visual acuity improves, while keratometric readings, spherical equivalent, and higher order aberrations reduce. Although published results prove CXL effective in the treatment of progressive keratoconus, its late consequences are yet unknown. This article reviews the stages of CXL development and results of published experimental and clinical studies. Prospects for CXL modifications that do not require epithelial debridement are discussed.

Objective: to determine optimal method of progressive myopia optical correction in children and adolescents.Patients and methods. Conducted 5-year prospective clinical and instrumental examination of 494 children with myopia using orthokeratology lenses, soft contact lenses and glasses. 61 children (the average age 11.7 ± 2.36 years) with myopia –2.87 ± 1.1 D and astigmatism –0.58 ± 0.27 D used orthokeratological lens. 92 children (the average age 12.8 ± 1.51 years) with myopia –3.66 ± 1.07 D, astigmatism –0.53 ± 0.18 D wore soft contact lens. 79 children (the average age 11.52 ± 1.78 years) with myopia –1.59 ± 1.08 D, astigmatism –0.71 ± 0.54 D used glasses with monofocal lenses, with full correction. The control group consisted of 249 children (the average age 9.1 ± 1.14 years) with initial emmetropia. Determination of refraction, subjective and objective determination of accommodation, and axial length of the eye (“IOL-master”) was conducted in children.Results. The maximum progression of myopia was observed in younger children (8–9 years). Correction of myopia with orthokeratology lenses (OKLs) was accompanied by the lowest dynamics of changes in axial length (axial elongation 0,44 ± 0,32 mm) compared to the correction with soft contact lenses (SCLs) (axial elongation 0,73 ± 0,36 mm), spectacle correction (axial elongation 1,39 ± 0,47 mm) and the control group (axial elongation 0,6 ± 0,41 mm). In all children with myopia, at the beginning of the study, there were reduced values reserve of relative accommodation and an objective accommodative response. Correction of myopia with OKLs (p = 0,0002) and SCLs (p = 0,036) provides the normalization of subjective and objective reserve indication of relative accommodation in both age group in comparison of spectacles correction.Conclusion. Correction with orthokeratology lens in children with progressive myopia contributes to the minimum growth length of the eye. Correction of myopia OKLs and MKL improves of subjective and objective indicators of relative accommodation reserve.

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Purpose: To analyze changes of functional parame¬ters and aberrations before fitting and after using rigid gas-permeable scleral lenses (RGPSCL) in patients with irregular cornea. Material and methods. 21 patients (29 eyes) with irregular astigmatism of various etiology were enrolled in this study. The patients could not achieve good visual aсuity in glasses, standard soft or rigid corneal contact lenses. Complex ophthalmologic examination was per¬formed: autorefractometry, visometry, biomicroscopy, computer corneal topography, aberrometry on “OPD-Scan II” (“Nidek”, Japan) before fitting scleral lenses and during the period of their wearing. Results and discussion. The results demonstrat¬ed significant visual acuity improvement after RGP¬SCL fitting in all observed patients. UCVA amounted to 0.1±0.18, BCVA in glasses amounted to 0.4±0.26, BCVA in RGPSCL amounted to 0.7±0.1. An increase of best-corrected visual acuity in RGPSCL was statistically significant in patients after keratoplasty, after intra-stromal corneal ring segments (ICRS) implantation, af¬ter refractive laser surgery (RLS) and in cases of mixed astigmatism. We have found that the correction of ker¬atoconus with the use of RGPSCL resulted in a decrease of the root mean square value (RMS), measured in the 3 mm and 5 mm zones by 2.5 times and 4 times, re¬spectively. In patients wearing RGPSCL after kerato¬plasty, statistically significant decrease in RMS was observed in the 3 mm zone (by 3.85 times) and in the 5 mm zone (by 2.99 times). In patients wearing RGPSCL after implantation of intrastromal corneal ring segment (ICRS), RMS in the 3 mm zone decreased by 1.5 times. In patients wearing RGPSCL after refractive laser surgery (RLS) RMS was 2.5 times lower in the 3 mm zone and 2.8 times lower in the 5 mm zone. In case of mixed astigmatism correction with RGPSCL, RMS increased by 1.6 times in the 3 mm zone and practically did not change in the 5 mm zone. Conclusion. The results obtained demonstrated significant visual acuity improvement in all observed patients. The sub-lens-space filled with tear forms a unified “cornea-tear-scleral contact lens” optic system that corrects unevenness of cornea, decreases amount of high-order aberrations (HOA) and provides a clear stable vision.