Purpose: To estimate the possibility of optical correction of an irregular surface of a cornea at primary ectasia (keratoconus) and secondary ectasia (a consequence of radial keratotomy (RKT) and Keratoplasty) for improvement of the maximum of visual acuity. Material and methods: In the study the scleral gas-permeable lenses (SGCL) were fitting by the 60 patients, it was 45 men and 15 women from them. The 46 patients had various stage of keratoconus and 14 patients had the keratectasia after RKT. On the 5 eyes of the patients was carried out keratoplasty earlier. Criteria of successful selection of SGCL considered achievement of steadily high visual acuity, comfort of carrying and the optimal clearance in apical zone, in the limbal and landing zone on the conjunctiva also. The results: In the course of the study, the maximum visual acuity in all patients was achieved with mini-SGKL correction irrespective of type of keratoektasia. All patients observed visual comfort compared with spectacle correction or correction with other types of contact lenses. Conclusion: Scleral gas-permeable contact lenses are the main method of correction at patients with irregular corneas and provide the best visual acuity.

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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.

Purpose: The purpose of the study is to determine the correlation between the incidence of giant papillary conjunctivitis induced by the use of contact lenses (CLPC) and contact lens material, replacement schedule or wearing time. The emergence of new materials and designs of contact lenses along with modifications in the replacement and wearing schedule have changed the structure of complications in users of soft contact lenses (SCLs). At present, infectious and hypoxic complications are extremely rare; on the other hand, toxic-allergic reactions that arise in users of contact lenses (CLs) have come to the fore. Material and methods. A retrospective cohort clinical study involved 1 668 users of SCL of various materials and with different replacement and wearing schedules. Patients were monitored from 2008 to 2018. Results. As a result of the study, it was found that the CLPC incidence correlate with the wearing time and replacement schedule of the SCLs.

Purpose. To analyze domestic and foreign scientific publications over the past 5 years, reflecting the issues of accommodation and accommodation disorders. To assess the presence or absence of changes in the classification of accommodation disorders. To evaluate the role of various accommodation disorders in the development and progression of myopia. Relevance. Given the significant increase in the number of people with myopia in recent decades, interest in the study of accommodation and accommodation disorders has increased again. This is due not only to the fact that accommodative insufficiency (AI, weak accommodation), is considered one of the leading factors in the development of myopia, but also because the use of one or another method of myopia control affects the process of accommodation, increasing or reducing accommodation reserves, affecting the functioning of the binocular system. New developments in the field of visualization of intraocular structures (anterior segment imaging by OCT, Sheimpflug imaging, UBM) allows carry out previously impossible studies of changes in the crystalline lens, ciliary body, at different levels of accommodation response, in different age groups in vivo, which itself affects the development and testing of new concepts related to the mechanism of the accommodation. Thus, the dynamics of the changes that are taking place motivates ophthalmologists to take a fresh look at the already established concepts of the accommodation mechanism, to assess the consistency of previously adopted approaches to the classification of accommodation disorders, which in turn can affect changes in the tactics of myopia control, which is especially crucial as myopization of the population, especially in children, is accelerating every day. Our task was to evaluate domestic and foreign scientific publications over the past 5 years, reflecting the results of studies of the accommodation mechanism, assessing the influence of accommodation disorders on the progression of myopia. The task was also to assess the prospect of creating a unified classification of accommodative disturbances, the ability to create a unified algorithm for controlling progression, based on accommodation parameters. Search strategy. A review of English and Russian sources related to the study of the mechanism of accommodation was conducted; the effect of accommodation disorders on the progression of myopia and their classification was studied using the following databases: PubMed, Cyberleninka, Google scholar, Elibrary. The search depth was 5 years (2014-2019), excluding the historical sources. The sources included: - original research; - historical issue, scanned publications; - studies / descriptions of accommodation disorders and their relationship with myopia; - abstracts and full-text publications; - literary reviews; - monographies. The exclusion criteria were: - themed issues with closed or restricted access. During the process of searching and processing information, the data obtained were not systematized according to the level of reliability due to the fact that the purpose of the review is to obtain a general idea of the views on this issue, assess the presence or absence of unity in the formation of diagnostic criteria, without the task of suggesting practical recommendations. The following search queries were made to search the databases: a) English-language sources - mechanism of accommodation, accommodation AND history issue, accommodation AND Helmholtz AND Tsherning, accommodation AND myopia, accommodation AND myopia control AND myopia progression, accommodation disorders OR accommodation anomalies, accommodative excess AND accommodative infacility AND accommodative insufficiency, epidemiology myopia AND etiology myopia, near work AND myopia AND children; b) Russian-language sources - the history of the study of accommodation, the mechanism of accommodation, classification of accommodation disorders, accommodation, accommodation disorders with myopia, accommodation and the progression of myopia, weakness of accommodation, habitual excess tension of accommodation; progressive myopia, myopia control.