This issue of the Acta biomedica scientifica journal presents reviews and original researches on modern problems of ophthalmology, carried out by specialists from various clinics, institutes and branches of the S. Fyodorov Eye Microsurgery Federal State Institution from St. Petersburg to Vladivostok. The editorial board of the journal is confident that these materials will be of interest to a wide range of doctors of various specialties. 

Background. In economically developed countries, age-related macular degeneration (AMD) is the leading cause of visual disability among the population of the older age group. The main criterion for the anti-VEGF treatment of neovascular AMD is the activity of choroidal neovascularization (CNV), which is determined by its confi guration. The search for optimal criteria for quantifying the state of the macular region in order to decide on the appointment of anti-VEGF therapy continues.
Aim: improving the effi ciency of diagnosis and treatment of AMD based on the assessment of the configuration of vascular system on the “Key to Diagnosis II” platform.
Material and methods. The study included 341 patients: 64 % (218 patients, 267 eyes) with non-neovascular AMD, 36 % (123 patients, 174 eyes) – with neovascular AMD. 56 patients (58 eyes) had active type I CNV. Group 1A – active CNV before treatment (9 patients, 9 eyes), group 1B – non-active CNV after treatment with antiVEGF (9 patients, 9 eyes); control group – 10 patients (10 eyes) without AMD. Analysis of OCT-angio images of choriocapillaries included the isolation of CNV, its area, fractal dimension (Df) and the complexity of the vascular system (CVS) counting.
Results. Group 1A: Df – 1.5871 ± 0.05, CVS – 2.29 ± 0.29, area – 11734 ± 4866; group 1B: Df – 1.6462 ± 0.08, CVS – 1.65 ± 0.18, area – 6797 ± 3818; control: Df – 1.9167 ± 0.06, CVS – 1, area – 0. Significant differences were found for CVS (p = 0.0003). Df correlates with the CNV area (p = 0.7) and is probably an unreliable parameter due to incomplete visualization of active CNV.
Conclusions. CVS is a quantitative biomarker for determining the activity of type 1 CNV in patients with AMD and can serve as a parameter for convolutional neural networks training for automated analysis of OCT angiography images based on the “Key to Diagnosis II” platform

Autoimmune polyendocrine syndrome type 1 (APS type 1) is a disease characterized by a variety of clinical manifestations resulting from the involvement of multiple endocrine and non-endocrine organs in the pathological process. APS type 1 is a rare genetically determined disease with autosomal recessive inheritance. Mutations in the autoimmune regulator gene (AIRE) lead to a disruption of the mechanism of normal antigen expression and the formation of abnormal clones of immune cells, and can cause autoimmune damage to organs. Within APS type 1, the most common disorders are primary adrenal insufficiency, hypoparathyroidism, and chronic candidiasis. Some understudied clinical manifestations of APS type 1 are autoimmune pathological processes in the eye: keratoconjunctivitis, dry eye syndrome, iridocyclitis, retinopathy, retinal detachment, and optic atrophy. This review presents the accumulated experimental and clinical data on the development of eye damage of autoimmune nature in APS type 1, as well as the laboratory and instrumental methods used for diagnosing the disease. Changes in the visual organs in combination with clinical manifestations of hypoparathyroidism, adrenal insufficiency and candidiasis should lead the clinical doctor to suspect the presence of APS type 1 and to examine the patient comprehensively. Timely genetic counselling will allow early identifi cation of the disease, timely prescription of appropriate treatment and prevention of severe complications.

This review analyzed the domestic and foreign literature on brachytherapy of choroidal melanoma using ruthenium ophthalmic applicators. The review highlights the historical aspects of radiation treatment, from the first experience of using ionizing radiation in the treatment of malignant neoplasms to modern methods of brachytherapy; presents the radiobiological foundations of radiation therapy; considers the issues of radiation pathomorphosis, reflecting the nature of pathological changes in the choroidal melanoma tissue during brachytherapy; shows the dependence of the effect of exposure ionizing radiation from the phase of the cycle of cell division; and also describes the presence of changes characteristic of the response to ionizing radiation in unirradiated tissues. The analysis of various post-radiation complications, both early and late, was carried out in some detail, with emphasis on the possibility of predicting and preventing them in real clinical practice. A comparison is made in terms of the frequency of development of various post-radiation complications in the works of domestic and foreign authors, as well as a comparison with the effect of ionizing radiation from other radioactive isotopes. Recommendations of experts are given regarding the correct calculation of the dose to the sclera and medication support, based on many years of experience in the use of ruthenium ophthalmic applicators for brachytherapy of choroidal melanoma. The risks of developing such late complications as radiation maculopathy and radiation neuropathy have been demonstrated, especially in pre-equatorial tumor localization. The possibilities of modern methods of instrumental diagnostics for studying the processes occurring in the area of the tumor, as well as changes in the surrounding tissues, are shown, which determines the feasibility and importance of further study of this issue.

In domestic and foreign medical periodical literature, highlighting the problem of ophthalmopathology against the background of coronavirus infection, the lesion of the anterior segment of the eye is most often described. It is extremely hard to find reports about pathology of the retina, optic nerve or central parts of the visual analyzer. However, it is widely acknowledged that there is a high risk of developing coagulopathy against the background of COVID-19 infection, which leads to occlusion and thrombosis of retinal vessels, ischemic neuropathies. The problem of irreversible loss of vision due to circulatory disorders of the retinal vessels was urgent even before the wide spread of coronavirus infection due to the high prevalence of atherosclerosis, hypertension and type 1 and 2 diabetes in the population. Also, it is widely known that occlusions and thrombosis of retinal vessels can be formidable harbingers of the developing life-threatening conditions. Knowledge about the high risk of vascular ophthalmopatology against the background of a previous COVID-19 infection by the primary echelon ophthalmologists, early diagnostics and treatment of ischemic conditions of the posterior segment of the eye will reduce the frequency of irreversible vision loss due to these diseases, secondary neovascular glaucoma cases, and will also help to send patients to the multidisciplinary hospitals in a timely manner for the prevention of fatal complications of coagulopathy. The article provides a brief overview of foreign literary sources regarding the history of outbreaks of coronavirus infection in the world, as well as possible ways of damage to the organ of vision by the coronavirus. A clinical case of damage to the vascular bed of the retina in both eyes due to coagulopathy against the background of pneumonia caused by COVID-19 is presented, which is actual due to the low illumination of similarly cases.

Background. After penetrating keratoplasty, mild to high induced corneal astigmatism was observed in each case. The existing choice of correction of postkeratoplastic astigmatism is aimed at fi nding an individual approach in order to compensate for it and not weaken the biomechanical properties of the corneal graft.
The aim: to analyze the clinical, functional, and morphological results of postkeratoplastic astigmatism correction by implantation of intrastromal corneal segments using a femtosecond laser.
Methods. 22 patients were examined before and 1 year after surgery. The operation was performed under local anesthesia: stage I – an intrastromal tunnel was formed using a femtosecond laser “Femto Visum” 1 MHz (Optosystems, Russia); stage II – the intrastromal corneal segments were implanted. The results were assessed using standard and special research methods using optical coherence tomography Visante OCT (Zeiss, Germany), keratotopography (Tomey-5, Japan), optical corneal analyzer ORA (Reichert, USA), laser tindalemetry FC-2000 (Kowa, Japan) and confocal microscope Confoscan-4 (Nidek, Japan).
Results. Before the operation, uncorrected visual acuity averaged 0.09 ± 0.05, after a year – 0.50 ± 0.16; best corrected visual acuity – 0.30 ± 0.12 and 0.60 ± 0.05 respectively; cylindrical component of refraction – –10.29 ± 3.12 and –2.20 ± 0.64 D respectively; mean keratometry value – 43.59 ± 2.14 and 38.56 ± 1.75 D respectively; corneal hysteresis – 7.92 ± 1.22 and 8.95 ± 1.05 mm Hg respectively; corneal resistance factor – 7.01 ± 1.81 and 8.44 ± 1.44 mm Hg respectively; protein fl ux in the moisture of the anterior chamber – 2.97 ± 0.28 and 3.04 ± 0.24 f/ms respectively; endothelial cell density – 1521 ± 327 and 1475 ± 419 cells/mm2 respectively.
Conclusion. Intrastromal corneal segments implantation into a corneal graft using a femtosecond laser has efficiency and safety method in correcting postkeratoplastic astigmatism.

The aim: to develop a mathematical model for predicting macular edema based on the informativeness of clinical and instrumental predictors of its occurrence.
Materials and methods. To determine the risk factors for macular edema 64 patients (64 eyes) with macula-off rhegmatogenous retinal detachment complicated by proliferative vitreoretinopathy (grade Cp 1–2) were selected. A retrospective analysis of the surgical treatment results was carried out. The age of the patients ranged from 30 to 81 years (28 women and 36 men).
Results. Using regression analysis, two signifi cant factors were identifi ed: the sum of 8 meridians of the visual fi eld before surgery (p = 0.015) and the number of detached quadrants (p = 0.021). Based on the identifi ed factors, a model was obtained for predicting the occurrence of macular edema in the postoperative period for the patients with rhegmatogenous retinal detachment. 
Conclusion. Based on the analysis of clinical and instrumental indicators in patients with rhegmatogenous retinal detachment, a mathematical model has been developed that allows predicting the occurrence of macular edema in the postoperative period.
The application of the proposed prediction model makes it possible to determine the tactics of treatment (peeling of internal limiting membrane) and predict the appearance of macular edema at the preoperative stage.

Epigenetic studies of the level of microRNAs in human oncogenesis indicate their signifi cant role in the development and growth of malignant tumors of various origins. The fi rst works on the role of microRNAs in patients with uveal melanoma appeared in 2008.
The aim: to analyze the expression level of miRNA-126 and miRNA-223 in the plasma blood of patients and to determine their signifi cance in the refi ned diagnosis of choroidal melanoma.
Materials and methods. We examined 84 patients with choroidal melanoma (CM), mean age – 63.4 ± 1.2 (35–86 y.o.). Localization – a single CM node with a thickness of 0.77–17.19 mm. The control group consisted of 28 volunteers, age – 62.9 ± 1.42 (45–78 y.o.). Plasma miRNA expression levels were determined by real-time PCR.
Results. An increase in the level of expression of miRNA-223 and miRNA-126 in blood plasma was confi rmed in all 84 patients with choroidal melanoma N0M0 compared with the control group. An increase in the expression of miRNA-223 and miRNA-126 was proved with an increase in tumor prominence.
Conclusion. The obtained results of an increase in the expression of miRNA-223 indicate an increase in cell proliferation, and an increase in the expression of miRNA-126 on the activation of angiogenesis in a growing tumor, which makes it possible to recommend a study of the level of miRNA-223 and miRNA-126 for a more accurate diagnosis of small CM in cases of difficulty of differential diagnosis with other tumor-like diseases of the choroid.

In the modern world, myopia continues to be one of the most common refractive errors and is considered a socially signifi cant problem, since it is a common cause of decreased vision. In connection with the growth of myopia, the risk of developing complications in the fundus increases, leading to the development of degenerative changes in the retina and an irreversible decrease in visual functions in young and middle-aged people. One of these complications is myopic choroidal neovascularization, which leads to a progressive, irreversible decrease in visual acuity and poor prognosis, and the process is often bilateral in nature. The tactics of managing patients with such complications has been determined: antiangiogenic therapy is used – intravitreal therapy with anti-VEGF drugs, which is currently the fi rst choice therapy for this pathology. But in some cases, antiangiogenic therapy is contraindicated, and the question arises about the tactics of managing such patients.
The aim: to study treatment options for myopic choroidal neovascularization in patients with myopia in different situations.
Material and methods. The paper presents two clinical observations of patients with mChNV, considers the tactics of their management. The patients underwent standard ophthalmological examination, optical coherence tomography (OCT) and OCT-Angio (OPTOPOL Technology, Poland).
Conclusions. Women with myopia planning pregnancy need a thorough examination not only by a clinician, but also by an ophthalmologist, since it is necessary to take into account not only the degree of myopia and choose the optimal delivery method, but also to study the state of the retina for the timely diagnosis of degenerative changes in the fundus.

The review assesses physical exercises as an additional non-pharmacological mean of combating the progression of primary open-angle glaucoma. The ophthalmic hypotensive effect is determined by the type of exercise, its duration and intensity. Moderate aerobic activity is preferred. Among dynamic exercises, jogging has the greatest hypotensive effect. Upper body isometric resistance training provides a more lasting decrease in ophthalmotonus. The decrease in intraocular pressure (IOP) in patients with glaucoma is several times more pronounced in comparison with healthy people and occurs regardless of the nature of the local drug antihypertensive therapy. After the termination of classes IOP returns to the previous level on average within a month. An increase in ocular perfusion pressure associated with physical activity dictates the appropriateness of physical exercise for patients with pseudo-normal pressure glaucoma. The combination of hypotensive, vascular, neuroprotective effects of physical activity with a high level of physical fi tness does not exclude a decrease in the risk of development and progression of primary open-angle glaucoma. The development of indications for the use of physical activity by patients with advanced glaucoma, including those who have undergone hypotensive surgery, remains relevant. The type, intensity, dosage and mode of performing the recommended physical exercises require an individual choice.

Background. The anatomical and functional results of surgery for retinopathy of prematurity (ROP) are determined not only by the stage of the pathological process, but also depend on the timing of its implementation.
The aim: to estimate the effectiveness of vitrectomy for severe active retinopathy of prematurity, depending on the timing of surgical treatment.
Methods. Vitreoretinal surgery was performed in 138 children (198 eyes) with severe stages of ROP. All patients were divided into three groups depending on the timing of surgical treatment: group 1 – 42–48 weeks of postconceptual age (PCA), with the progression of ROP after laser coagulation of the retina (LCS), group 2 – 39–41 weeks of PCA, with the progression of ROP after LCS, group 3 – 36–39 weeks of PCA, without previous LCS. A 3-port transscleral 27-G vitrectomy was performed by all patients. At the postoperative period, the results of vitrectomy were estimated by the anatomical attachment of the retina. The follow-up period was 12 months.
Results. In group 1, in 31 cases (73.8 %), the surgical intervention was completed with silicone tamponade. By the end of the follow-up period, anatomical retinal attachment was achieved in 17 eyes (40.5 %).
In group 2, surgical intervention was completed with silicone tamponade in 29 eyes (42 %). By the end of the follow-up period, anatomical retinal attachment was achieved in 52 eyes (75 %).
In group 3, surgical intervention was completed with silicone tamponade in 11 of 87 eyes (12.6 %). Anatomical retinal attachment was achieved in 80 eyes (92 %).
Conclusion. Untimely vitrectomy (42–48 weeks of PCA) in cases of ROP progression after LCR led to a worse result. If progress of ROP after laser treatment happens, early vitrectomy (39–41 weeks of PCA) should be performed. Primary vitrectomy should be performed in case of the optimal timing of laser treatment has been missed (after 36 weeks of PCV).

Adequate analgesia determines the success of the performed surgical intervention. In modern surgery, most of postoperative complications are directly related to ineffective therapy of pain syndrome in the perioperative period. The main principle of modern analgesia is its multicomponence, when analgesia, neurovegetative blockade and relaxation are achieved and potentiated by different drugs and methods. The blockade of nociceptive impulses with a local anesthetic at the transmission stage provides effective, targeted analgesia, hyporefl exia and muscle relaxation, prevents the sensitization of neuroaxial structures, hyperalgesia and the development of postoperative chronic pain syndrome. At the same time, providing analgesia with drugs of central action leads to the ineffectiveness of therapy in 80 % of cases, which has serious consequences.
The aim. According to the literature review, to evaluate the effectiveness and safety of peripheral blockades on the example of performing a blockade of the pterygopalatine ganglion.
Conclusion. The pterygopalatine blockade has broad indications for use in ophthalmology, which is explained by the complex structure of the pterygopalatine ganglion and the possibility of simultaneous infl uence on sympathetic, parasympathetic and nociceptive innervation. All the presented methods of pterygopalatine blockade performance have their advantages and disadvantages. Ultrasound navigation eliminates technical difficulties and the possibility of damage of the pterygopalatine fossa anatomical structures, ensuring the effectiveness and safety of the pterygopalatine blockade.

Background. The characteristic optical coherence tomography (OCT) changes in the optic nerve head in patients with multiple sclerosis are known and have been described many times, however, the state of the macular area is described in a small number of publications.
The aim: to analyze the changes in the macular area of the retina in patients with multiple sclerosis, to identify the OCT signs pathognomonic for this disease and to trace their changes over time as the disease progresses.
Material and methods. In addition to the standard ophthalmological examination, 28 patients (55 eyes) diagnosed with multiple sclerosis underwent OCT of the macular zone to determine the thickness of the fovea and the volume of the macula in the 6 mm zone. The follow-up period was 6–12 years. The endpoints were the primary treatment and the most recent inspection.
Results. At the initial examination, the visual acuity was 0.96 ± 0.24 (95% CI: 0.9–1.03), fovea thickness – 253.0 μm (Q1–Q3: 233.0–264.0), macular volume – 5.471 mm³ (Q1–Q3: 5.281–5.625). In 37 cases (67.3 %), the macular volume was below normal. The initial fovea thickness was below normal in 9 cases (16.4 %). At the end of the study, visual acuity did not change statistically (p = 0.824) and amounted to 0.96 ± 0.25 (95% CI: 0.90–1.04). The fi nal thickness of the fovea was 247.5 μm (Q1–Q3: 233.0–260.0), changes are statistically significant (p = 0.02). Number of cases with a thickness below normal in the fi nal study was 11 (20 %), change of frequency of cases was not statistically signifi cant (p = 0.5). The fi nal macular volume was 5.393 mm³ (Q1–Q3: 5.197–5.565), the changes are statistically significant (p = 0.023). The final number of cases with a volume below the norm was 42 (76.4 %), the change in the frequency of cases is close to statistically signifi cant (p = 0.063). At all stages of the study, there was no case of an isolated decrease in the thickness of the fovea without a decrease in the volume of the macula.
Conclusion. The decrease in the volume of the macula with time while maintaining the thickness of the fovea within the normal range can be attributed to the pathognomonic OCT signs of multiple sclerosis. This criterion can be used for a comprehensive assessment of the course and therapy of this disease.

Background. Optical coherence tomography angiography (OCT-A) is a promising tool for the detection of microvascular impairment at the preclinical stage of diabetic retinopathy (DR). Evaluation of dynamic OCT-A changes and their association with systemic factors can help to reveal early biomarkers of DR progression.
Aim: to evaluate time-related OCT-A changes and their association with systemic factors in type 1 diabetes mellitus (DM1) patients with no apparent DR
Materials and methods. 38 DM1 patients with no apparent DR and 39 healthy volunteers were included in the study. All participants underwent 7-fi eld fundus photography, OCT and OCT-A. We analyzed OCT-A parameters (foveal avascular zone (FAZ) area (mm2), acircularity index (AI), vessel density (VD), skeletonized density (SD)) as well as the results of blood and urea tests.
Results. After one year of observation, AI was significantly higher (р = 0.005) and VD0–300 was signifi cantly lower in superfi cial vascular plexus (SVP, p < 0.0001) and deep capillary plexus (DCP, р = 0.032) in DM1 patients. We have also registered a positive correlation between AI and triglycerides (TG) level (r = 0.627, p = 0.007) as well as a negative correlation between ketones and VD (SVP VD0–300: r = –0.695, p = 0.030; intermediate capillary plexus (ICP, VD0–300: r = –0.551, p = 0.041; DCP, VD0–300: r = –0.704, p = 0.003; SVP, VD300–600: r = –0.853, p = 0.001).
Conclusions. After one year of observation, we have registered an increase in AI level and a decline in VD in SVP and DCP which can be the earliest signs of DR progression. A signifi cant correlation between these parameters and systemic factors indicates their role as potential DR biomarkers.

Background. Optical coherence tomography angiography (OCTA) is currently an important method of visualization and assessment of fundus pathology in various diseases. The study of combined pathologies is not well covered.
The aim: to compare OCTA features during choroidal neovascularization (CNV) in pathological myopia (PM) and in neovascular age-related macular degeneration in combination with axial myopia (nAMD + M) against the background of anti-VEGF therapy.
Materials and methods. A prospective study included 70 eyes with active CNV. Comparative analysis of parameters was carried out between two groups: with PM – 47 eyes; with nAMD + M – 23 eyes.
Results. 4 OCTA patterns were established in both groups: dense, loose, mixed and unidentifi able. With PM, dense pattern was found in 28 (59.57 %) eyes, loose pattern – in 16 (34.04 %), mixed pattern– in 2 (4.26 %), unidentifi able pattern – in 1 (2.13 %). In the nAMD + M group, dense pattern was rare – in 1 (4.35 %) eye, loose pattern – in 7 (30.44 %), mixed pattern – in 9 (39.13 %), unidentifi able pattern – in 6 (26.08 %). The fi rst group was characterized by a dense pattern that was found at a younger age, the second group was characterized by dense and mixed patterns. The greatest area and density of CNV were found with a loose pattern in both groups (p < 0.05). The observation period until the stabilization of CNV was achieved was longer in the loose and mixed patterns in the PM group, and in the loose and unidentifi able – in the nAMD + M group (p < 0.05). Loose and unidentifi able patterns require more injections. The halo was determined by the presence of intraretinal fluid in the retina.
Conclusion. OCTA showed common features and distinctive features in the course of CNV in patients with PM and nAMD + M during anti-VEGF therapy. OCTA can be useful in assessing CNV activity and predicting the eff ect of treatment.

Background. Diabetic macular edema (DME) is one of the main causes of decreased central vision. Determining the reasons for the refractoriness of DME to treatment is an urgent problem.
Aims. Based on the analysis of optical coherence tomography, to study the features of pathological changes in the retina and vitreoretinal interface (VRI) in the macular zone in patients with DME.
Materials and methods. We studied 587 patients (587 eyes) with diffuse DME in the setting of nonproliferative diabetic retinopathy. In addition to the standard ophthalmological examination, everyone underwent optical coherence tomography of the macular zone with an assessment of structural changes in the retina, morphometric parameters, and the state of the VRI.
Results. In 351 patients (59.80 %) with DME, pathological variants of the VRI were revealed, in which the best corrected visual acuity was significantly lower, and the morphometric parameters (retinal thickness and macular volume) were signifi cantly higher. Analysis of morphostructural changes in the macular zone revealed that in pathological VRI, neuroepithelial detachment and high edema are more common, and cystic edema is larger in area compared to the group with a normal VRI. With detachment of neuroepithelium against the background of a pathological VRI, the worst morphometric data are determined, with solid exudates in the macula, the worst indices of visual loss are determined.
Conclusions. The pathological VRI in patients with diabetic macular edema occurs in more than half of the cases and is characterized by a high incidence of neuroepithelial detachment, high edema, higher morphometric parameters with worse visual acuity. At the same time, the presence of neuroepithelial detachment corresponds to the worst morphometric indicators of the macular zone, and the presence of solid exudates corresponds to a lower maximum corrected visual acuity. Further research is needed to assess the effect of the listed morphostructural and morphometric changes in combination with various pathological variants of VRI on the effectiveness of DME treatment.

The endothelial NO synthase (eNOS) and vascular endothelial growth factor (VEGF) imbalance and the polymorphism of these genes may be the predisposition for diabetic retinopathy (DR) development and progression.
The aim: to analyze VEGF (rs699947 and rs3025039) and eNOS (rs2070744) genes polymorphism and their combinations in patients with type 2 diabetes mellitus (DM2) with and without initial non-proliferative DR.
Materials and methods. The study included 200 patients with type 2 diabetes (155 women and 45 men, age – 43–70 years): 111 people without and 89 people with DR. The polymorphism of the regulatory regions of VEGF (rs699947 and rs3025039) and eNOS (rs2070744) genes was studied using restriction fragment length polymorphism analysis and TaqMan Real-Time PCR by. Statistical processing was carried out using the software packages Statistica 10.0, SPSS Statistics 23 and the package of original programs for volumetric processing of bioinformation.
Results. The VEGF-2578 heterozygosity and two complex genotypes – VEGF-2578CA:VEGF+936CC and NOS3-786CT:VEGF-2578CA:VEGF+936CC – signifi cantly decreased in patients with DR. The predisposition to early DR development to minor genotype of eNOS gene in the NOS3-786CC:VEGF+936CT complex and signifi cantly decreased the homozygous wild-type eNOS genotype in DM2 patients with ophthalmopathology were shown. NOS3-86TT:VEGF2578AA genotype signifi cantly decreased in group with retinopathy developing and the glycated hemoglobin high level.
Conclusion. Along with the clinical risk factors for the development of DR in DM2, the genetic polymorphism of the regulatory regions of the genes analyzed by us has a signifi cant weight. When analyzing potential genetic markers, it is important to consider possible joint epistatic/hypostatic effects. The complex analysis of polymorphic gene can help early prognosis of the DR development.

Background. Recently, more and more attention has been paid to the development of vascular retinal disorders after suffering preeclampsia. It is noted that the key role in this process is assigned to the systemic endothelial dysfunction that persists for a long time after delivery.
Aim: to elucidate the features of vascular-platelet and coagulation hemostasis in relation to the indicators of blood flow in the macular region in women with preeclampsia.
Materials and methods. The main group included 45 women with preeclampsia in the third trimester of pregnancy (35–36 weeks). Their age ranged from 19 to 40 years (27 ± 5.2 years). The comparison group was represented by 20 women with physiological pregnancy in the third trimester (35–36 weeks). Their age averaged 26 ± 5.1 years (18–38 years). Somatically healthy non-pregnant women (20 people) were included in the control group. Their age ranged from 19 to 38 years (26 ± 5.4 years). A comparative analysis of the studied parameters of macular blood fl ow, vascular-platelet and coagulation hemostasis between the groups was carried out.
Results. When studying the number of platelets in pregnant women, it turned out that in patients with preeclampsia, this indicator was statistically signifi cantly lower compared to the comparison and control groups (p < 0.05). The level of fi brinogen in women with complicated pregnancies was statistically significantly higher than in women with physiological pregnancy and in somatically healthy nonpregnant women (p < 0.05). In addition, retinal microcirculation disorders were observed in women of the main group.
Conclusions. The revealed disorders of vascular-platelet and coagulation hemostasis in women during the period of complicated pregnancy were accompanied by disorders of macular blood fl ow in the form of a decrease in the total average density of vessels in the superfi cial vascular plexus, subfoveolar thickness of the choroid and an increase in the area of the avascular zone relative to the group of women with physiological pregnancy and somatically healthy nonpregnant women.

The aim: to evaluate the restoration features of the structural relationships of the retina and chorioretinal blood fl ow after surgical treatment of large-diameter macular hole (MH) using a modifi ed technology.
Material and methods. A prospective study of 14 patients (14 eyes), 13 women and 1 man, with medium-and large-diameter MH was conducted. The mean age of the patients was 67.7 ± 5.38 (55–80) years. The study included patients with endto-end MH of the 3^rd–4^th stage according to the classifi cation of J. Gass. All patients underwent surgical treatment of macular rupture according to the proposed method of inverted fl ap of the internal limiting membrane (ILM) and fi lling it into a “pocket” formed between the retina and the ILM.
Optical coherence tomography (OCT) was performed along with traditional research methods. The obtained images were used to measure manually the parameters of retinal MH, the thickness of the choroid in the projection of the rupture and the fovea zone before the operation and 1, 3 and 6 months after the operation. In the angio-mode, the foveal avascular zone (FAZ) was evaluated, as well as the density of capillaries of the superfi cial and deep retinal plexus in four quadrants, with the exception of the central zone.
Results. In all patients, it was possible to achieve MH blocking. Visual acuity in the eyes with MH varied from 0.02 to 0.3, while in the comparison group, the best corrected visual acuity was from 0.3 to 1.0 (p = 0.002). An increase in the diameter of large choroidal vessels, as well as a pronounced decrease in the diameter of the posterior short ciliary artery, attracted attention. However, despite the improvement in visual acuity, patients retained a signifi cant expansion of the FAZ, which by 6 months exceeded the FAZ area of the paired eye by 25.8 % (p = 0.01).
Conclusion. The results obtained indicate that the achievement of an anatomicalreconstructive effect and even a moderate improvement in visual acuity during surgical treatment of macular holes by the modifi ed inverted flap technology of the internal limiting membrane does not determine the restoration of retinal perfusion in full.

Terahertz (THz) radiation is one of the new, intensively studied interdisciplinary fi elds of scientifi c knowledge, including medicine, in the fi rst decades of the 21^st century. At the beginning of this article (review), in a brief form, the basic statements on THz radiation, the main parameters and properties are presented; the modern THz biophtonics technologies used in biology and medicine are considered – THz refl ectometry, THz spectroscopy methods. Then a number of directions and examples of possible use of THz technologies in biology and medicine, including pharmaceuticals, are given. The main part of the review presents the progress of experimental research and the prospects for the clinical application of medical technologies of THz spectroscopy, THz imaging, in ophthalmology in the study of the morphological and functional state of the ocular surface structures, diagnosis, medical testing, and treatment of ophthalmopathology of the ocular surface. The article concludes with a review of experimental studies on the safety of using THz waves for medical diagnostics and treatment of ophthalmopathology. In the fi nal part, the main problems and prospects of introducing medical THz technologies into the clinical practice of an ophthalmologist are considered.

Background. At an appointment with an ophthalmologist, patients with pathological conditions of the eyelids are often dissatisfi ed with the effectiveness of the traditional surgical treatment.
The aim: assessment of the functional state of the eye adnexa after cryodestruction of the chalazion with an increased risk of complications using modern cryosurgical equipment.
Material and methods. Clinical studies were carried out in 254 patients (277 eyes) with chalazion, including a complicated course of the disease, with cryodestruction of the chalazion using an autonomous cryoapplicator made of porous-permeable titanium nickelide.
Results. Cryosystems of the new generation, in comparison with the well-known industrial cryoapparatus, diff er in new properties. They can signifi cantly improve the quality of cryotherapy in surgery due to a clearer localization of cryotherapy and a high rate of heat removal from the surface of altered tissues without damaging the surrounding tissues. Depending on the size of the pathological formation, the duration of the exposure, the frequency of repetitions of the applications during the session, the regression of the chalazion occurred within 1–1.5 months with the preservation of the integrity of the intermarginal space and the functional state of the eyelid.
Conclusion. Analysis of the data obtained indicates a high clinical and cosmetic effi ciency of cryosurgery of the eyelid chalazion using an autonomous cryoapplicator made of porous-permeable titanium nickelide.

Detachment of the pigment epithelium is the separation of the basement membrane of the retinal pigment epithelium from the inner collagen layer of Bruch’s membrane, which occurs in 80 % of cases in patients with neovascular age-related macular degeneration. The outcome of anti-VEGF therapy for pigment epithelial detachment may be adherence of the pigment epithelium, the formation of pigment epithelium tear, or preservation of the detachment. The pigment epithelium tear of 3–4th degrees can lead to a sharp decrease in visual acuity.
Most retrospective studies confi rm the absence of a proven correlation between anatomical and functional outcomes in the treatment of pigment epithelial detachment in cases of maintaining the integrity of the pigment epithelium monolayer, and therefore the main attention of researchers is focused on studying the morphological features of pigment epithelial detachment during therapy with angiogenesis inhibitors. Modern technologies of spectral optical coherence tomography make it possible to evaluate detailed quantitative parameters of pigment epithelium detachment, such as height, width, maximum linear diameter, area, volume and refl ectivity within the detachment.
Groups of Russian and foreign authors identify various biomarkers recorded on optical coherence tomography images. Dynamic registration of such biomarkers expands the ability of clinicians to predict morphological changes in pigment epithelial detachment during anti-VEGF therapy, as well as to optimize treatment regimens to prevent complications in the form of pigment epithelium tear leading to a decrease in visual acuity.
Modern methods of deep machine learning and the use of neural networks allow achieving higher accuracy in diff erentiating the types of retinal fluids and automating the quantitative determination of fl uid under the pigment epithelium. These technologies allow achieving a high level of compliance with manual expert assessment and increasing the accuracy and speed of predicting morphological results of treatment of pigment epithelium detachments.

Keratoconus (KC) is a progressive degenerative corneal disease, leads to the aberration of biomechanical and optical properties and thinning of the cornea, causes astigmatism and decreases visual acuity.
Materials and methods. 33 patients (35 eyes) with stages II–III of non-progressive keratoconus and concomitant cataracts of various stages of maturity were operated on. The average age of the patients was 46.5 ± 2.7 (41–63) years old. The operations were performed according to our proposed two-stage method of treating ametropia in patients with KC and cataracts (Patent of the Russian Federation No. 2748634 of 28.05.2021). The first stage was the implantation of FERRARA intrastromal corneal ring segments (ICRS) with thickness from 150 to 350 μm. To correct residual refractive error in 5–7 months after stage 1, patients underwent stage 2: cloudy lens was removed and replaced with toric posterior chamber intraocular lens (TIOL) – AcrySof IQ Toric (Alcon, USA), T-fl ex Toric RayOne (Rayner, UK).
Results and discussion. After stage 1 of the operation (ICRS implantation), the uncorrected visual acuity (NCVA) was 0.2 ± 0.03, the best corrected visual acuity (BCVA) was 0.4 ± 0.02. In 1 month after stage 2 (phacoemulsifi cation + TIOL) NCVA was 0.64 ± 0.11 and BCVA was 0.74 ± 0.12. During the entire follow-up period after the surgery visual functions, refraction, and rotational stability of TIOL were stable.
Conclusions. Conducting a two-stage surgical intervention in patients with keratoconus and cataracts allows to stop the progression of the disease and effectively correct the ametropia concomitant with keratoconus.

One of the most common surgical interventions in ophthalmology today is lens replacement surgery. But there is still no consensus on whether the choice of a monofocal IOL affects the postoperative functional outcome.
The aim: to conduct a comparative analysis of values of visual acuity without correction in the early postoperative period after cataract surgery using monofocal IOLs.
Material and methods. The study included data of 2643 eyes operated for cataract, into which one of the monofocal IOLs, included in the top ten most frequently implanted IOLs in the Orenburg Branch of the S. Fyodorov Eye Microsurgery Federal State Institution, was implanted for the period 2019–2021. Statistical analysis was performed using the program Statistica 13.0.
Results. The performed analysis of variance showed that the established differences between the compared groups are statistically signifi cant (p < 0.05). However, the subgroup analysis showed that there were statistically signifi cant differences between pairs such as Tecnis and Hydro-4; Tecnis and Rayner. In all other cases, statistically signifi cant uncorrected visual activity (UCVA) values after surgery were not established. It has also been reliably established that the presence of subluxation of the lens affects the value of UCVA after surgery.
Conclusion. The results of the performed analysis in general indicate that the value of UCVA in patients in the early postoperative period after the performed surgical intervention does not depend on the manufacturer of the used IOL.

Background. In the available literature, there are isolated publications devoted to the topic of the possible effect of laser correction by the Femto LASIK method on the myopic eye choroid. In this connection, in our opinion, the relevance of continuing research in this direction remains.
The aim of this study was to examine the volume of the retina in the macular zone, the thickness of the choroid and the ciliary body using optical coherence tomography on myopic eyes after femtosecond-assisted laser in situ keratomileusis in the short term.
Material and methods. 30 patients (30 right eyes) aged 20 to 35 years, suffering from mild and moderate myopia, but without pathological changes in the retina according to OCT, made up the study group. All patients underwent myopia correction using the Femto LASIK method. Before the operation, after 4 hours and the next day, they underwent the examination of the retinal volume in the macular zone, the choroidal and the ciliary body thickness using OCT
Results. The analysis of the obtained results of the studied parameters showed that the ciliary body thickness and the retinal volume in the macular zone did not undergo statistically signifi cant changes and remained within the preoperative values (p > 0.05). We observed a tendency to an increase in the thickness of the choroid 4 hours after the operation, but the carried out statistical analysis did not confi rm the reliability of its changes (p > 0.05). On the next day, the choroidal thickness indices practically recovered to the preoperative level (p > 0.05).
Conclusion. A study of the retinal volume in the macular zone, the thickness of the choroid and ciliary body using OCT in myopic eyes in the short term after Femto LASIK showed the absence of statistically signifi cant changes in the studied parameters, which indirectly indicates the safety of this method of laser correction for the posterior segment of the eye.

For the treatment of progressive keratoconus in the early stages, corneal collagen crosslinking is currently actively used. This technique is based on the stabilization of the pathological process by increasing the biomechanical properties of the own cornea. The thickness of the cornea less than 400 microns significantly limits the possibility of a standard cross-linking procedure performing.
The article analyzes the literature data on the use of various methods of corneal crosslinking with a corneal thickness of less than 400 microns, which signifi cantly limits the possibilities of the standard procedure.
It is known, that during crosslinking, at the initial stage, de-epithelialization of the cornea is performed, which, in the postoperative period, leads to a pronounced corneal syndrome. This determined the direction of the fi rst modifi cations of the technique associated with the use of partial de-epithelialization or its complete absence. Later, during cross-linking of “thin” corneas, techniques with the use of additional covering materials were actively used in order to replenish the missing corneal tissue of the patient during the UV irradiation procedure. Among them are the use of a soft contact lens without an ultraviolet fi lter, the use of a corneal lenticule obtained after SMILE surgery, the use of a protective fl ap of the donor cornea obtained using a femtosecond laser from the residual stroma of the corneal disc after descemet membrane transplantation or posterior lamellar keratoplasty. The variety of the proposed modifications and the ongoing search for better options indicate the demand for this technology and the need for further research, taking into account the individual characteristics of the patient’s ectasia.

Background. Choroid plays an important role in the pathogenesis of retinal pathology. Choroidal cavern, a recently identifi ed fi nding of optical coherent tomography (OCT), has been described in some degenerative and atrophic forms of retinal pathology. In the literature, there are only a few studies of choroidal cavers in pachychoroid neovasculopathy, newly described form of age related macular degeneration.
The aim: to perform a detailed analysis of choroidal structure on OCT scans of patients with pachychoroid neovasculopathy and to reveal the frequency of choroidal caverns identifi cation.
Material and methods. The data of 30 patients (30 eyes) aged 64.4 ± 5.6 years with pachychoroid neovascularization were retrospectively analyzed. The patients underwent spectral OCT and OCT-angiography (OCTA) using a Spectralis device (Heidelberg Engineering, Germany). The protocol was “Posterior Pole”, consisting of 61 scans. To assess the structure of the choroid, an enhanced image depth (EDI) module was used. OCT angiography was performed with a scan area of 6 × 6 mm. These methods were compared to identify choroidal caverns.
Results. On OCT subretinal type 1 neovascularization was revealed as a fl at detachment of the pigment epithelium and visualization of blood flow on OCTA in the lesion as angled vessels (21 eyes) or a seafan (9 eyes). On OCT-EDI scans, there was diffuse or local choroidal thickening of choroid with an increase in the vessels of the Haller’s layer and thinning of the choriocapillaries. Choroidal caverns appeared on OCT and en-face OCT as areas with low optical density, round or irregular, located in different layers of the chorioid, without hyperrefl ective boundaries. A typical sign of choroidal cavern is the tail of hypertransmission after the cavern toward the sclera. Choroidal caverns were found in 4 of 30 eyes (13.3 %) and were located both near the choroidal neovascularization lesion and beyond this area.
Conclusion. The prevalence of choroidal cavities, a new choroidal biomarker, in pachychoroid neovasculopathy was 13.3 %. Identification of these changes is possible with the use of modern diagnostic techniques (OCT-EDI, OCTA and en-face OCT) that allow visualization the state of the choroid. The prognostic signifi cance of choroidal cavities requires further study.