Репозиторий Университета

© 2018 Media Sfera. All rights reserved. The article reviews development mechanisms of different refractive errors accompanied by marked defocus of light rays reaching the retina. Terminology used for such ametropias includes terms extreme, ultra-high and complicated. Justification of their usage for primary ametropias, whose symptom complex is based on changes in axial eye length, is an ongoing discussion. To comply with thesaurus definitions of «diagnosis» and «pathogenesis», to characterize refractive and anatomical-functional disorders in patients with primary ametropias it is proposed to use the terms «hyperaxial and hypoaxial syndromes» with elaboration of specific symptoms instead of such expressions as extreme (ultra-high) myopia and hypermetropia.

© 2017 Astro Ltd. A two-photon laser femtosecond crosslinking process at the wavelength of 525 nm was studied in a human donor cornea in the presence of riboflavin using two-photon optical microscopy and nanoindentation. It was shown that such an approach results in efficient crosslinking of the corneal collagen and a significant (three-fold) increase in the Young's modulus of the corneal structure. Application of a femtosecond laser with the wavelength of 525 nm allows a drastic enhancement of efficiency in the presence of riboflavin on human corneas and a 50-fold reduction of the laser treatment duration in comparison with the use of a femtosecond laser with the wavelength of 760 nm. We relate this effect to a significant growth in the coefficient of two-photon absorption due to the laser wavelength falling within the edge of the photoinitiator (riboflavin) absorption band. Our studies on a donor human cornea demonstrate the good potential for the clinical application of a femtosecond laser with the wavelength of 525 nm for increasing the cornea rigidity using the two-photon laser femtosecond crosslinking technique.