Актуальность. Авторами данной статьи представлен новый способ препарирования мембран, отличительной особенностью которого является формирование ультратонких срезов исследуемого препарата, что позволяет более детально изучить строение эпиретинальных и внутренних пограничных мембран, удаляемых с поверхности сетчатки при хирургическом вмешательстве по поводу эпиретинального фиброза. Цель. Представить ультраструктурные особенности удаленных в ходе хирургического вмешательства эпиретинальных и внутренних пограничных мембран с использованием новой методики препарирования, а также сравнить точность интраоперационной оценки характера удаляемой мембраны по сравнению с иммуногистохимическим исследованием. Материал и методы. В исследовании участвовало 6 пациентов (6 глаз) с диагнозом «идиопатический эпиретинальный фиброз». Пациентам было выполнено хирургическое вмешательство, в ходе которого удаленные образцы эпиретинальных и внутренних пограничных мембран были подвергнуты фиксации по авторской методике и иммуногистохимическому окрашиванию. Результаты. Полученные данные подтверждают, что ламинин β2 является характерным маркером внутренней пограничной мембраны. При сравнении интраоперационного определения характера удаленных мембран и данных иммуногистохимического исследования было установлено, что последний способ является, в ряде случаев, недостаточно точным. Заключение. Полученные в рамках данного исследования результаты ставят под сомнение возможность сохранения внутренней пограничной мембраны в ряде случаев хирургии по поводу эпиретинального фиброза, а также указывают на неточность оценки типа удаляемой мембраны в ходе оперативного вмешательства.

Human posterior corneal epithelium (corneal endothelium) has limited proliferative activity both in vivo and in vitro. Disease or dysfunction in these cells leads to impaired corneal transparency of varying degrees of severity, up to blindness. Currently, the only effective standard treatment for corneal endothelial dysfunction is transplantation of donor cornea that contains a pool of healthy and functionally active cells. However, there is a global shortage of donor corneas, which has led to an unmet clinical need and the fact that only 1 patient out of 10 in need receives surgical treatment. Therefore, creation of cellular constructs and artificial human corneas containing healthy endothelium is a very urgent challenge facing modern ophthalmic transplantology. This review presents the current state of affairs, challenges and prospects for obtaining cultured corneal endothelial cells (CECs) in vitro for transplantation purposes.

Dry eye syndrome (DES) is a multifactorial disease of the ocular surface, which is based on the development of hyperosmolarity, inflammation and sensorineural disorders due to an imbalance of the structural components of the tear film. The main complaints of refractive patients after keratorefractive surgery are a feeling of dryness in the eyes, a foreign body, redness, blurring of the image, which is due to the clinical manifestations of post-refractive DES. Today, along with the general standard and modern methods of examining the ocular surface, laboratory screening also occupies an important place. Modern laboratory diagnostics of DES includes examination of tears and goblet cells of the conjunctiva to identify potential root causes of this condition. Enzyme immunoassay is a sensitive and specific method for the quantitative determination of inflammatory mediators in lacrimal fluid. To assess the condition of the aqueous mucin layer of the tear film, it is possible to conduct a cytological examination of the conjunctiva in order to verify the diagnosis of DES. Keywords:tear film, dry eye syndrome, cytokines, goblet cells, keratorefractive surgery

Original article Experimental study of manual and femtosecond laser-assisted methods for cutting limbal mini-transplants B.E. Malyugin, S.A. Borzenok, O.N. Nefedova, D.S. Ostrovskii, M.Yu. Gerasymov, A.V. Shatskikh S. Fyodorov Eye Microsurger y Federal State Institution, Moscow, Russian Federation A. Yevdokimov Moscow State University of Medicine and Dentistr y, Moscow, Russian Federation Purpose. To define optimal parameters of femtosecond laser (FSL) (Femto LDV Z8, Ziemer, Switzerland) for cutting limbal mini-transplants to be further used for limbal stem cells (LSC) transplantation and compare the results with manual cutting technique using microsurgical blade. Material and methods. At first step, performed on 3 porcine and 3 cadaveric eyes, the optimal energy parameters of FSL were selected, which ensured the excision of limbal mini-transplants. At the second step, 8 eyes from 4 postmortem donors were used. In the lower and upper parts of the limbus, limbal fragments were cut out into 8 mini-transplants with a FSL (experimental group). Mini-grafts were also formed manually in symmetrical areas of each eye using dosed diamond blade (control group). The structure of the limbal bed after removing mini-transplants was studied by light and scanning electron microscopy. The effect of FSL energy on the viability of LSC was determined by intravital staining using Live & Dead dye. Finally, on the third step, the assessment of reversible and irreversible apoptosis was performed by culturing corneoscleral discs containing mini-transplants not separated from the limbal bed. The obtained samples were cultivated in a medium DMEM/F12 for 7 days followed by immunohistochemical examination. Results. The optimal parameters of FSL operation are determined by energy levels- 100, 110 and 120%. Histological analysis of the limbal residual bed zone showed that the smoothest surface was obtained at energies 110 and 120%. This fact was also confirmed by scanning electron microscopy. When stained with the Live & Dead dye, damage on the lateral and inner sides of limbal mini-transplants was revealed, mainly in the experimental group. After 7 days of cultivation in the cut area in both groups, no expression of apoptosis markers was observed. Conclusion. Cutting out the limbal zone containing LSCs using FSL is safe and allows obtaining limbal mini-grafts. The most optimal parameters of laser operation in the limbal zone were selected – a planar cut at depth of 250 µm using 110% laser energy. Key words: femtosecond laser, limbal stem cells, apoptosis, limbal stem cell deficiency syndrome, scanning electron microscopy, light microscopy, cultivation, histology

The effect of recombinant spidroin (RS) hydrogel (HG) on anterior epithelial cells and keratocytes of the human cornea was studied in vitro. Corneal injuries are highly prevalent in developing countries according to the World Health Organization. Various technologies have recently been proposed to restore the damaged surface of the cornea. Use of biodegradable silk-based materials, including recombinant analogs of the spider silk protein spidroin, is an important avenue of research in the field of wound healing and corneal regeneration. Spidroins are well known for their optimal balance of strength and elasticity. Given their biological compatibility, lack of immunogenicity, and biodegradability, spidroins provide a biomaterial for tissue engineering and regenerative medicine. HGs based on RS rS2/12-RGDS were therefore tested for cytotoxicity toward isolated corneal epithelial cells and keratocytes with regard to possible changes in cell phenotype and migratory activity. A promising outlook and therapeutic potential were demonstrated for RS-based HGs.

Background. According to the World Health Organization, corneal diseases are one of the major causes of blindness globally. Endothelial dystrophy is one of the etiological factors leading to corneal diseases. The corneal endothelium is a monolayer of cells with virtually no mitotic activity. When the density of corneal endothelial cells falls below a critical threshold, the endothelium loses its ability to regulate corneal stromal hydration. This leads to corneal clouding and, consequently, to reduced visual acuity and quality of life of the patient. In this regard, various keratoplasty methods are widely used in clinical practice. Today, it is technically possible to transplant all corneal layers via penetrating keratoplasty, and to transplant the posterior epithelium via layer-bylayer keratoplasty. These surgical approaches are now widely used in everyday practice, but they require the use of scarce material – cadaveric donor corneas, from which grafts for the above-mentioned operations are formed in the conditions of an eye bank. In this regard, protocols for obtaining human corneal endothelial cell (HCEC) culture for subsequent transplantation have been proposed in recent years. However, the use of such approaches in Russia is limited by the law. The aim of this study was to experimentally justify the possibility of transplanting uncultured endothelial cells, isolated from cadaveric human corneas. Materials and methods. The first stage of the work consisted of obtaining a suspension of endothelial cells from cadaveric donor corneas and studying it; at the second stage, the transplantation effectiveness of the resulting cell suspension was assessed in an ex vivo experiment. Results. The cell phenotype after transplantation by the proposed method had high viability and preservation. Conclusions. The presented results suggest that phenotype and adhesion ability are preserved, and that the cell suspension has a high level of viability under adequate loss of endothelial cells during transplantation in the ex vivo experiment.

Актуальность. На сегодняшний день вирусы группы герпеса остаются ведущим фактором инфекционной природы, поражающим роговицу человека. Так, по оценкам отечественных ученых, герпетические кератиты являются ведущей причиной роговичной слепоты среди населения России: более 66 % всей роговичной патологии связаны с контаминацией роговичной ткани вирусами группы герпеса. Вирус простого герпеса способен передаваться через донорский трансплантат, в связи с чем предложена технология вирусной деконтаминации трансплантата роговицы на этапе консервации. Цель. Изучение влияния композиции раствора для деконтаминации на экспрессию характерных маркеров эндотелиальных клеток роговицы в эксперименте in vitro. Материал и методы. В экспериментальном исследовании использовались трупные донорские роговицы человека, полученные из Глазного тканевого банка ФГАУ «НМИЦ «МНТК «Микрохирургия глаза» им. акад. С.Н. Фёдорова» Минздрава России в количестве 12 штук от 6 доноров-трупов, с присутствием вируса простого герпеса 1-го типа, верифицированного по данным ПЦР. Роговицы разделялись на две группы. B опытную группу вошли роговицы, которые консервировали по предложенной технологии в растворе для вирусной деконтаминации (n= 6) при температуре +37 °С в течение 24 часов (для выработки эндогенных интерферонов), после чего переносили в раствор для хранения роговицы. В контрольную группу (n= 6) вошли роговицы, которые консервировали по стандартной методике в растворе для хранения роговицы, используемом в Глазном тканевом банке, при температуре 4 °С. Спустя 6 суток консервации роговицы выводили из эксперимента и проводили иммуногистохимическое исследование (ИГХ). В опытной и контрольной группе сравнивалась экспрессия фермента Na + /K + -АТФазы как маркера насосной функции, и маркера плотных межклеточных контактов ZO-1, характеризующего сохранность эпителиальной природы исследуемых клеток. Результаты. Среднее значение экспрессии Na+/K+-АТФазы в опытной и контрольной группах составляло 0,0060 ± 0,0014 и 0,0058 ± 0,0015 относительных единиц соответственно. Среднее значение экспрессии маркера плотных межклеточных контактов ZO-1 в опытной и контрольной группах составляло 0,0048 ± 0,0017 и 0,0049 ± 0,0019 относительных единиц соответственно Достоверных отличий в уровнях экспрессии Na+/K+ -АТФазы и ZO-1 между группами выявлено не было (р> 0,05). Заключение. Консервация роговиц в растворе для вирусной деконтаминации до 6 суток не оказывает влияния на изменение уровней экспрессии характерных маркеров эндотелиальных клеток роговицы при сравнении с консервацией по стандартной методике на тех же сроках наблюдения.

Purpose. To evaluate experimentally endothelial cell loss of animal's cornea during inverted posterior lamellar corneal graft preparation technique by low-energy femtosecond laser with and without ophthalmic viscosurgical device (OVD) – 1% hydroxypropyl methylcellulose (HPMC) solution application. Material and methods. Posterior lamellar corneal grafts were created using a femtosecond laser (FSL). In the control group (n=16), a few drops of corneal storage solution were applied to the endothelium just before applanation, in the experimental group (n=16) – 1% HPMС. The quality of the applanation were monitored using an integrated in laser OCT system. The endothelial viability was determined using live/dead cells assay and the grafts were examined on a confocal laser scanning microscope. The obtained images were analyzed to count live and dead endothelial cells (EC). To assess the state of collagen fibers of the stromal side of the graft, samples from the control and experimental groups were examined using a scanning electron microscope (SEM). Results. According to the OCT, in all samples of both groups, a flat profile of the contact zone between the laser head and the endothelial monolayer was observed during applanation. The difference between the number of live and dead ECs was statistically significant between both groups. There were 2854 [2819; 2879] live cells/mm² in the control group, and 3477 [3426; 3719] live cells/mm² in the experimental group (p<0.001). Thus, the number of dead ECs in the control group was 710 [649; 728] cells/mm² . The number of dead ECs in the experimental group was 402 [366; 427] cells/mm² (p<0.001). When analyzing the images obtained on a SEM, the preservation of the architectonics of the graft collagen fibers with their single defibrations in both groups was observed. Conclusion. Application of 1% HPMC provides protection for endothelial cells from damage during posterior laser dissection using an FSL. In the study group, the number of endothelial cells was 9.92% higher than in the control group. The presence of the OVD layer in the interface between the head of the FSL and the EC did not affect the formation of an effective laser cut and did not reduce the quality of the stromal surface of the graft. The inverted technique FSL cut using a 1% solution of HPMC on the surface of the endothelium may be recommended for use in clinical practice. Key words: endothelium, keratocytes, corneal transplantation, keratoplasty, posterior lamellar keratoplasty, femtosecond laser, ophthalmic viscosurgical device, hydroxypropyl methylcellulose, confocal microscopy, scanning electron microscopy

Relevance. Corneal transplantation with entire cornea or anormal layers replacement remains the only treatment option for patients with corneal endothelium pathology. Selective endothelial replacement was introduced into practice two decades ago, namely posterior lamellar keratoplasty, which has advantages over penetrating keratoplasty. Improvements of this method led to technique creation where isolated Descemet's membrane with endothelium monolayer without stromal layer is transplanted. This technology is associated with risks of intra- and postoperative complications, and is difficult to perform. Nowadays, development is in progress of introducing corneal endothelial cells (CECs) transplantation without stromal layer and even without Descemet's membrane. CECs transplantation in suspension form has potential to change treatment approach of corneal endothelium pathologies giving possibility of rapid eyesight recovery and reducing need for graft material. Purpose. To evaluate effectiveness of corneal CECs suspension transplantation on cadaver eye in ex vivo experiment. Material and methods. CECs suspension was obtained by modified enzymatic method. CECs transplantation experiment consisted of 3 stages. Firstly, CECs loss was calculated depending on cell administration method. Secondly, corneoscleral button was used as recipient for the obtained suspension. The third stage was carried out on cadaver eyeball. Results. The viability of transplanted CECs and their effective adhesion to Descemet's membrane was confirmed in this experiment. The characteristic markers of CECs ZO-1, Na+/K+ -ATPase, Ki67 were determined in corneal samples by immunohistochemistry assay and single cells expressing Vimentin were detected after one-week cultivation. Conclusion. Based on transplantation experiment results, it can be noted this technique is quite promising in surgical rehabilitation of patients with corneal endothelial dysfunction. Thus, it seems relevant to continue research to achieve the main goal – to fully cover the defect of central zone of corneal posterior surface with isolated CECs given that their morphology and functional activity are preserved. Key words: cornea, endothelial corneal dystrophy, endothelial cell suspension, corneal endothelial cell transplantation

Objective: to study in vitro survival and preservation of the proliferative activity of limbal stem cells (LSCs) in femtosecond laser-cut limbal tissue fragments. Materials and methods. Limbal fragments were formed from donor cadaver eyes (n = 8) in the upper and lower limbus containing the highest number of limbal stem cells, using a Z8 femtosecond laser (FSL) (Ziemer, Switzerland). The limbal fragments were fragmented into 4 mini-grafts using different energy levels (100, 110, 120%). Mini-grafts from symmetrical sections of the cadaver eyes, which were manually isolated using a microsurgical blade, served as controls. The mini-grafts were cultured for two weeks in culture media intended for limbal epithelial stem cells (LESCs) (Epilife (0.06 mM Ca++) and for multipotent mesenchymal stem cells (MMSCs) (DMEM/F12), with the addition of specific growth factors to selectively stimulate LESCs or MMSCs, respectively. The phenotype of the obtained cultured cells in the «laser» and «knife» groups was determined by flow cytometry using a set of markers (CD166, CD105, CD90, CD29, CD34) for the membrane proteins of LESCs and MMSCs. The ability of cultured cells to adhesion and proliferation in the «laser» and «knife» groups was determined by seeding the third passage of the resulting cultures on Bowman’s membrane of acellular corneas.Results. Primary cell culture was obtained from mini-grafts of all donors in both groups. Cell morphology was consistent with the phenotype of corneal epithelial cells (cobblestone pattern). When cultured in the EpiLife medium (0.06 mM Ca++), we determined the presence of LSCs proliferation from 38.6% of minigrafts; in the DMEM/F12 medium (1 : 1) the presence was determined from 31.8%. Two weeks later, cell yield from mini-grafts in the «laser» and «knife» groups was 77.2% and 63.6%, respectively. Cell growth by the end of week 2 of culturing of mini-grafts obtained by FSL at 120, 110 and 100% energies was 87.5, 71.4 and 71.4%, respectively. It was found that the resulting cell cultures in the «laser» and «knife» groups and in the «120%», «110%» and «100%» subgroups were not different phenotypically. Cytofluorimetric analysis showed that cell cultures in the groups had a mixed pattern of marker expression of both LESCs (CD29+) and MMSCs (CD90+, CD105+). Seeding of the third passage of cell culture in the test groups in all cases demonstrated adhesion and formation of a cell monolayer on the Bowman’s membrane of model corneas.Conclusion. The use of FSL for cutting out limbal grafts seems to be effective and safe in comparison with the traditional mechanical (knife) technique. Cell cultures obtained from FSL-cut mini-grafts were able to grow and migrate for at least 21 days.

Dry eye syndrome is a multifactorial disease of the ocular surface, which is based on the development of hyperosmolarity, inflammation and sensorineural disorders in the imbalance of the structural components of the tear film. The main complaints of refractive patients after keratorefractive surgery are a feeling of dryness in the eyes, a foreign body, redness, blurring of the image, which is due to the clinical manifestations of post-refractive dry eye syndrome. There are factors that contribute to the development of postrefractive dry eye syndrome, such as: neurotrophic epitheliopathy, postoperative inflammation, damage to goblet cells, toxic corneal epitheliopathy caused by preservatives contained in eye drops, leading to inadequate restoration of the tear film. In clinical practice, to assess the stability of the tear film, a method is used to determine the tear film rupture time using invasive and non-invasive methods. Invasive methods include: staining of the ocular surface with a solution of fluorescein during the Norn test. To date, laboratory diagnostics expands the understanding of the pathogenesis, etiology and mechanisms underlying the xerosis of the ocular surface at the molecular level, and also facilitates the diagnosis and prognosis of dry eye syndrome. Laboratory methods of the ocular surface include the study of biomarkers of lacrimal fluid, conducting impression cytology with an assessment of the condition of goblet cells. In this regard, it is necessary to have a deep understanding of the main etiopathogenetic links of dry eye syndrome, a wide range of diagnostics of the condition of the ocular surface before and after the surgical stage of patient management, which will determine the success of keratorefractive surgery and a stable course of the postoperative period.

Lipofuscin granules from retinal pigment epithelium (RPE) cells contain bisretinoid fluorophores, which are photosensitizers and are phototoxic to cells. In the presence of oxygen, bisretinoids are oxidized to form various products, containing aldehydes and ketones, which are also potentially cytotoxic. In a prior study, we identified that bisretinoid oxidation and degradation products have both hydrophilic and amphiphilic properties, allowing their diffusion through the lipofuscin granule membrane into the RPE cell cytoplasm, and are thiobarbituric acid (TBA)-active. The purpose of the present study was to determine if these products exhibit a toxic effect to the RPE cell also in the absence of light. The experiments were performed using the lipofuscin-fed ARPE-19 cell culture. The RPE cell viability analysis was performed with the use of flow cytofluorimetry and laser scanning confocal microscopy. The results obtained indicated that the cell viability of the lipofuscin-fed ARPE-19 sample was clearly reduced not immediately after visible light irradiation for 18 h, but after 4 days maintaining in the dark. Consequently, we could conclude that bisretinoid oxidation products have a damaging effect on the RPE cell in the dark and can be considered as an aggravating factor in age-related macular degeneration progression.

The purpose of the study was to establish a simple ex vivo corneal re-epithelization model and study the labial mucosal epithelium grafting as a potential approach for ocular surface reconstruction. Four human donor corneal buttons were overstored in a corneal cold storage solution at 4 C for 32-52 days. Four labial oral mucosa strips were dissected from four patients during fornix reconstruction after they signed informed consent. The substantia propria was trimmed off, and the resulting graft was sutured near the corneal limbus with running sutures (thus forming the tissue construct). Constructs were cultured under the standard conditions with the anterior corneal side outwards. After 3 weeks of culture, constructs were removed, washed, and fixed. Sections were stained with hematoxylin and eosin (HE), anti-keratins 4, 13, 19, and p63. Nuclei were counterstained with Hoechst. After the cultivation, all constructs were integral with the attached graft and non-loosened sutures. The native cells were absent in all donor corneas. Histological evaluation demonstrated that the labial mucosal grafts were attached to the Bowman's membrane (BM), and its cellular outgrowths were found to be transit from the graft to the BM over the anterior surface in all constructs. Cells expressed mucosal epithelial keratins 4, 13, and 19, and several were p63-positive in nuclei. In the study, a simple ex vivo corneal re-epithelization model was successfully established. The model was potent in studying the labial mucosal epithelium grafting as an option for autologous ocular surface reconstruction in patients with bilateral limbal stem cell deficiency.

An Erratum to this paper has been published: https://doi.org/10.1134/S1990793122310025

A comparative study of individual groups of bisretinoids and their oxidation and degradation products in chloroform extracts from cells of the retinal pigment epithelium (RPE) of human cadaver eyes without signs of pathology (norm) and in the case of visualized age-related macular degeneration is carried out. Fluorescence analysis and high-performance liquid chromatography-mass spectrometry show that with age-related macular degeneration, an increased content of oxidation and degradation products of bisretinoids are observed in comparison with the norm. The results obtained allow us to conclude that the listed methods can be used in the preclinical diagnosis of degenerative diseases of the retina and the RPE of the human eye.

Relevance. Limbal stem cell deficiency (LSCD) is a pathology that leads to substantial vision decrease, corneal neovascularization, corneal epithelial persistent erosions and have a negative impact on patient's the quality of life. It is known that the efficiency of corneal transplantation in LSCD patients is low and requires repeated interventions. One of the important problems is the lack of a clear diagnostic algorithm and a standardized set of diagnostic techniques for this condition. Purpose. Systematically analyze domestic and foreign literature on the currently existing methods for diagnosing LSCD. Material and methods. A systematic analysis of scientific publications from 1992 to 2021 was carried out. Its included domestic and foreign authors on the resources of PubMed, Medline, eLibrary, as well as dissertations and textbooks devoted to currently existing methods for diagnosing LSCD. Results. In addition to biomicroscopy, the main in vivomethods for diagnosing LSCD are staining of the ocular surface, impression cytology with the detection of specific cytokeratins, confocal microscopy, optical coherence tomography of the anterior segment (OST) and OST-angiography. Conclusion. Physician awareness and vigilance are required for the diagnosis of LSCD, especially in patients with conjunctivalization and corneal neovascularization. It is impossible to use only biomicroscopy and the patient's complaints, since LSCD is not always obvious. That is why diagnostics should include an integrated approach, including all available research methods, which are briefly described in Table No. 1 with their disadvantages and advantages. Key words: limbal stem cell deficiency, impression cytology, laser confocal scanning microscopy, goblet cells, cytokeratin, penetrating keratoplasty, cytokines

Purpose. Development of method for obtaining a suspension of native human corneal endothelial cells. Material and methods. To obtain a suspension of native endothelial cells, 20 corneoscleral discs isolated from the enucleated eyes of experimental animals (pigs) and 28 cadaveric corneoscleral discs isolated from cadaveric donors (human) were used. In the course of the work, the following isolation methods were used to obtain a cell culture: mechanical, enzymatic, as well as modified versions of these methods proposed during the experiment. Results. It was revealed that mechanical and modified mechanical methods of isolation make it possible to obtain more than 95% of corneal endothelial cells. The use of the enzyme method gave low results, which did not exceed 15% of the isolated endothelial cells, which was explained by the absence of direct mechanical action to separate the cells from the Descemet's membrane (DM). There was no statistically significant difference in the groups of porcine and human corneas for mechanical and enzymatic isolation. The modified enzyme method on human corneas provided 100% isolation of corneal endothelial cells with DM. When analyzing the purity of the suspension, it was found that mechanical and modified mechanical extraction methods do not exclude the ingress of large particles. In the samples obtained by the enzymatic method, these particles were absent. At Comparison of the modified methods for isolating the suspension of endothelial cells revealed their statistically significant difference, in particular, lower rates of contamination with foreign particles were noted with the modified enzyme method. Conclusion. The conducted experimental study is the first stage in the development of an effective and safe method for obtaining suspensions of endothelial cells, for their subsequent cultivation or use in clinical practice to replace defects in the endothelial layer, for example, in patients with bullous keratopathy. Key words: endothelial cells, cultivation, corneal transplantation, endothelial keratoplasty, surgical technique, cell lines.

Purpose. To analyze an algorithm for infectious screening of cadaver corneal donors during corneal processing at the Eye Tissue Bank (ETB) of The Fyodorov Eye Microsurgery Federal State Institution and compare it with the European Eye Bank Association (EEBA) data from 2011 through 2015. Material and methods. Data analysis were done using the ETB in-house donor data registry and EEBA annual directory forms. The extracted data included the number of received eye globes, rates of inconclusive and serological tests for human immunodeficiency virus (type 1 and 2), Hepatitis B and C viruses, and Syphilis. Results. During the analyzed period 3479 eye globes were delivered in the ETB for the processing. Hemolysis caused exclusion for 13.9% (n=486) of corneas in the ETB. In opposite, the EEBA data demonstrated far lower rates of inconclusive tests. The positive serology tests lead to canceling 19.4% (n=676) of the incoming corneas in the ETB. Overall, the rates of positive tests were far higher in comparison with EEBA data. At the ETB, positive serological tests for HIV (type 1 and 2) and Syphilis had low variability annually, while the rates of Hepatitis B increased in 2015. Predomination of Hepatitis C was also noted. Often enough, the blood samples were multiply-infected. Conclusion. Overall, the positive serology and hemolysis were the major contraindications and led to exclusion 33.4% (n=1162) of incoming corneas in the ETB. Serological tests rates for indicated infections were higher in the ETB with predomination of Hepatitis C. An algorithm for infectious screening at the Eye Tissue Bank (ETB) of The S. Fyodorov Eye Microsurgery Federal State Institution was effective in selection of postmortem donors for cornea processing in clinical use. Key words: cornea transplantation, eye bank, serological tests, human immunodeficiency virus, hepatitis B viruses, hepatitis C virus, syphilis

На сегодня известно, что биодеградируемые конструкции на основе фиброина шелка могут использоваться в качестве безопасного носителя биологически активных веществ и лекарственных препаратов. При этом последние исследования показали, что глиальный нейротрофический фактор является одним из необходимых факторов роста, участвующих в восстановлении роговичной ткани. Однако не изучен способ восстановления роговичных повреждений при помощи биодеградируемых конструкций на основе фиброина шелка, содержащих глиальный нейротрофический фактор, что объяснило цель данного исследования. Цель: изучить особенности восстановления роговичных повреждений при помощи биодеградируемых конструкций на основе фиброина шелка, содержащих глиальный нейротрофический фактор. Материалы и методы: Исследование проводилось на половозрелых самцах мышей линии C57BL/6. У животных формировали модель повреждения роговицы. В ходе эксперимента у мышей на 1-е, 3-и и 5-е сутки после повреждения проводили анализ площади эпителиального дефекта роговицы для оценки интенсивности регенеративного процесса. Результаты: установлено, что интенсивность регенеративного процесса была выше в группах мышей с применением биодеградируемых конструкций на основе фиброина шелка, содержащих глиальный нейротрофический фактор, по сравнению с контрольной группой. Выводы: Применение биодеградируемых конструкций на основе фиброина шелка, содержащих глиальный нейротрофический фактор, стимулирует процесс восстановления роговичной ткани после моделированного повреждения. Background: Today it is well known that biodegradable materials based on silk fibroin can be used as safe carriers of biologically active substances and drugs. At the same time, recent studies have shown that glial neurotrophic factor is one of the essential growth factors involved in corneal tissue regeneration. However, the method of restoring corneal damage with biodegradable materials based on silk fibroin containing glial neurotrophic factor has not been developed. Aim: To study pathogenetic features of corneal damage repair with biodegradable structures based on silk fibroin containing glial neurotrophic factor. Materials and Methods: The study was conducted on mature male C57BL/6 mice, in which corneal damage was modeled. During the experiment, the area of the epithelial corneal defect was assessed for the intensity of the regenerative process on days 1, 3, and 5 after injury. Results: In the groups of mice where biodegradable structures based on silk fibroin containing glial neurotrophic factor were used, the intensity of the regenerative process was higher compared to the control group (p < 0.05). Conclusion: The use of biodegradable structures based on silk fibroin containing glial neurotrophic factor stimulates the process of corneal tissue regeneration after corneal damage.