Progressive myopia remains one of the urgent problems in modern ophthalmology. Optical methods for controlling progressive myopia suggest the formation of peripheral myopic defocus, which has a stabilizing effect on the axial length of the eye and, as a result, the degree of myopia. One option for optical control of myopia is defocus soft contact lenses.

Purpose: to evaluate the growth of axial length and changes in the spherical equivalent of clinical refraction in users of defocus (bifocal) contact lenses and monofocal glasses expressed in diopters, against the background of the correction of progressive myopia with defocus (bifocal) contact lenses and monofocal glasses.

Materials and methods. The study involved 256 patients with bilateral mild to moderate and high myopia in the range from (–)0.5 to (–)  7.75  D in spherical equivalent and an annual progression gradient from 0.65 to 1.5 D in the age categories 7–10, 11–14, 15–18 years old. Depending on the degree of myopia and the method of correction, the patients were divided into main and control groups. For correction in the main groups, defocused (with an addition of +4.0 D) soft contact lenses (SCLs) were used. In the control groups monofocal glasses were used. All patients underwent a standard ophthalmological examination. Clinical refraction data and axial length of the eye were used as criteria for evaluating the results. The follow-up period was 3, 6, 12 months.

Results. After 12 months of wearing bifocal soft contact lenses, there was a statistically significant slowdown in the growth of the axial length and the spherical equivalent of refraction Higher rates of progression of myopia were in young children (7–10 years). Myopia at the age of 15–18 years is characterized by a decrease in the rate of progression with any type of optical correction and in most cases does not require the appointment of correction with the formation of peripheral myopic defocus.

Conclusion. The results obtained indicate the effectiveness of the use of bifocal SCLs in the control of progressive mild, moderate and high myopia. The main stabilization factor is the formation of peripheral myopic defocus on the retina, followed by a slowdown in the growth of the axial length of the eye and the degree of myopia (spherical equivalent of clinical refraction).

Relevance.  The new Increased Depth of Focus (EDOF) Intraocular Lens (IOL) technology is designed to improve the correction of visual acuity at a medium distance without compromising distance vision correction and provides a restoration of visual acuity in the distance and at an average distance, but at the same time a lower frequency of side optical phenomena and better contrast sensitivity compared to other multifocal IOLs (MIOL). Regardless of the technology used and the type of lens, the result of surgery and patient satisfaction depend on the optimization of the calculation of the optical strength of the IOL. To date, there is no consensus in the available literature on the choice of a formula for calculating the optical power of known EDOF IOLs.

Aim. Retrospective analysis of the accuracy of 7 formulas for optical power calculation of a new extended depth of focus intraocular lens.

Methods. The retrospective study included 34 patients (62 eyes) with implantation of a new EDOF Tecnis Symfony IOL ZXR00. The mean age of the patients was 61.9 ± 9.4 (39–87) years. IOL optical power range was +5.0 to +30.0 D, target refraction was –0.25 to 0.25 D. The average follow-up period for the patients was 12.3 ± 1.8 months. The SRK/T, Barrett Universal II, Haigis, Hoffer Q, Holladay 2, Olsen, and Kane formulas were retrospectively analyzed for effectiveness using appropriate constants. Each formula was optimized for the study group of patients to achieve an average refractive error as close to zero as possible. For each formula, the mean error (ME), mean absolute error (MAE), standard deviation (SD), median absolute error (MedAE), maximum absolute error (MaxAE), and percentage of eyes within the error range of 0.25, 0.5, 1.0, and 2.0 D were calculated.

Results. The optimized constants were LF = 2.21, a0 = 1.43, a1 = 0.39, a2 = 0.12, personalized ACD=5.68, ACD (Hoffer Q / Holladay 2) = 5.68/5.66, A-constant (SRK/T / Kane) = 119.5/119.4. For the SRK/T, Barrett Universal II, Kane and Haigis formulas the lowest MAE is shown. Application of the Hoffer Q and Holladay 2 formulas are associated with the highest MAE. The Barrett Universal II, SRK/T, Kane, and Haigis formulas were characterized by the highest percentage of reaching refraction of ±0.25 D (64, 62, 59, and 53, respectively). For all of the formulas examined, the frequency of reaching refraction of ±1.00 D was greater than 90% and within ±2.00 D greater than 97%.

Conclusion. This study was the first to retrospectively compare seven formulas for calculating the optical power of a new intraocular lens with an enhanced depth of focus. The SRK/T, Barrett Universal II, Haigis, and Kane formulas are recommended for calculating the optical power of the indicated IOL in clinical practice.

The evolution of treatment technologies and changing requirements for them dictates the development of a strategy for their implementation in clinical practice. The fi rst stage is the assessment of the capabilities, effectiveness, advantages and disadvantages, the development of indications and contraindications on models of eye diseases in the experiment.

The purpose of the work: to conduct a comparative analysis of experimental models of neovascularization of the eyes of different localization, their reproducibility and compliance with natural analogues of human diseases.

Material and methods. In an experiment 2 models of chorioretinal neoangiogenesis and 2 models of corneal localization were studied. All models employed the eyes of one biological species of experimental animals – rabbits of the Chinchilla breed (n = 60). Further, the advantages and disadvantages of each of the used models of eye neoangiogenesis were analyzed empirically. The correspondence of the formed experimental models in animals to natural human diseases was checked by fl uorescence angiography, optical coherence tomography and histological research methods.

Results. All 4 experimental models demonstrated clinical signs of neovascularization with different clinical manifestations, verifi ed angiographically, morphometrically (OCT models 1 and 2; in vivo) and histologically (models 1–4; ex vivo). The percentage of neovascularization “yield” on different models varied from 75 to 100%. Models of chorioretinal neovascularization were closer in clinical manifestations to the natural manifestations of the neovascular form of age-related macular degeneration. However, anterior localization models were preferred because of the free access, ease of reproduction, and good visualization of the area of interest, allowing monitoring during treatment. At the same time, angiogenesis in these models has a different nature and partly other mechanisms in which infl ammatory reactions play an important role. However, these models make it possible to conduct a comprehensive assessment of the pathological process with a quantitative count of the newly formed vessels in the cornea, including their length, the diameter of their lumen, to assess the usefulness of the anatomy of the vascular wall, the composition and density of the paravasal cell microenvironment. Taken together, this is of no small importance in preclinical trials of technologies with the claimed angiostatic effect.

Conclusion. To obtain a full amount of information about the test drug with the declared angiostatic potential, it is necessary to use several models of neoangiogenesis with different mechanisms of pathogenesis, on which one can study the range of their capabilities and side effects, as well as evaluate the entire range of biological effects.

Background. The ability to read is the key to successful education of schoolchildren and students. At the same time, according to various authors, from 5–10 to 20–30% of the population experience difficulties, characterized as “reading below the level of language proficiency”, “reading difficulties” and “dyslexia”. This work is devoted to the analysis of modern Russian and foreign literature in the field of aetiopathogenesis, diagnosis, clinical manifestations and functional correction of visual disorders in dyslexia.

Aim: to study the literature data on visual impairment in patients with dyslexia.

Materials and methods. The literature analysis of publications available on PubMed, eLibrary, CyberLeninka and Crossref Metadata Search was carried out.

Results. The conducted analysis demonstrates the importance of effective detection of visual disorders in patients with dyslexia, which is necessary for a correct comprehensive assessment of this condition, as well as understanding the causes and nature of difficulties experienced by a child with dyslexia in the process of learning to read. The results of the analysis of studies reveal the possibilities of positive dynamics in the development of reading skills in patients with dyslexia in the process of functional treatment aimed at developing binocular visual functions, improving the functioning of the oculomotor system and the accommodation.

Conclusion. The authors conclude that an in-depth ophthalmic examination and treatment of the identified ophthalmic pathology is of great importance in the overall complex of diagnostic and corrective measures in patients with dyslexia.

Currently, the following technologies are used in the production of contact lenses: lathe cut, polymerization in the form (cast molding) and centrifugal molding (spin cast). The last two technologies, due to the low cost of production, have been established in the mass production of soft contact lenses with standard parameters.

Methods of production of contact lenses are constantly being improved to obtain products that better meet the requirements of patients in terms of safety, comfort and customization.

The main methods of production of contact lenses are already localized in Russia and remain available to domestic consumers in conditions of geopolitical instability.