[Subthreshold micropulse laser treatment of the foveal region in chronic central serous chorioretinopathy (case study)]. / Subporogovoe mikroimpul'snoe vozdeistvie v foveal'noi oblasti pri khronicheskoi tsentral'noi seroznoi khorioretinopatii (klinicheskoe nablyudenie).

The article presents a clinical case of subthreshold micropulse laser (SML) treatment of chronic central serous chorioretinopathy (CSC) in the left eye of a 44-year-old female patient K. with dye allergy. The patient first noticed a gray spot, distortion of objects in February, 2018. During 2018-2020 she suffered 5 relapses, repeated unsuccessful conservative treatment, and completed a course of antiangiogenic therapy in the form of three monthly intravitreal injections of ranibizumab. After experiencing stress on 11.08.20 she noted acute deterioration. Laser treatment was carried out on 20.09.20 with the Navilas 577s navigation system (wavelength 577 nm). After the power titration and calculation, the contact-free subthreshold micropulse laser treatment was carried out without anesthesia in three zones: 200 mW for fovea, 240 mW for parafovea and 340 mW for periphovea. Other settings: pulse duration - 200 ms, spot diameter - 100 µm, duty cycle - 5%. Total number of laser pulses - 1000. The retina reattached completely despite the patient having previously recovered from the coronavirus infection and the use of corticosteroids.

[Widefield optical coherence tomography as an effective method for detecting imperceptible flap retinal tears (clinical observation)]. / Shirokopol'naya opticheskaya kogerentnaya tomografiya ­ effektivnyi metod vyyavleniya klapannogo razryva setchatki (klinicheskoe nablyudenie).

Certain late peripheral ruptures after acute posterior vitreous detachment (PVD) may remain undetected during the initial examination of the fundus due to the presence of vitreous hemorrhages and other factors, but they can lead to rhegmatogenic retinal detachment in the future. Hence, it is necessary to conduct an additional thorough examination using optical coherence tomography (OCT) of the vitreoretinal interface periphery in the presence of tear predictors: retinal and vitreal hemorrhages, vitreous pigment cells ("tobacco dust") in the anterior segment of the vitreous body, as well as hyper-reflective dots ("starry sky") in the vitreous body according to OCT scans of patients with acute symptomatic detachment of the hyaloid membrane. The article presents the case of a patient with a clinically imperceptible flap tear detected during acute posterior vitreous detachment. Widefield OCT of the vitreoretinal interface was performed by "sliding" from the center to the periphery of the retina, and revealed a flap tear located next to a dot retinal hemorrhage. OCT scanning of the retinal periphery is an effective modern diagnostic method in the ophthalmological clinical practice.

[Evaluation of choriocapillaris with high-speed spectral-domain optical coherence tomography angiography and image averaging]. / Otsenka statusa khoriokapillyarisa s pomoshch'yu vysokoskorostnoi spektral'noi opticheskoi kogerentnoi tomografii s funktsiei angiografii i tekhnologii usredneniya izobrazhenii.

PURPOSE: To study the capabilities of high-speed spectral-domain optical coherence tomography angiography (SD-OCTA) with image averaging in the evaluation of choriocapillaries in healthy individuals and patients with central serous chorioretinopathy (CSC). MATERIAL AND METHODS: All participants underwent OCTA examination on the SOLIX tomograph (Optovue, USA) using quadruplicate 3×3 mm scan with image averaging. Image analysis was performed in 9-µm custom slab with Phansalkar auto local threshold algorithm and calculation of flow voids larger than 5000 µm2 and 10 000 µm2. The optimal slab depth was determined in healthy eyes by consecutive analysis of the slabs with a 3-µm shift from zero position to 33 µm below Bruch's membrane. RESULTS: The study included 18 eyes of 18 healthy volunteers (40.4±6.0 years old) and 18 fellow eyes of 18 unilateral CSC patients (37.4±10.7 years old). The slab 12 µm below the Bruch's membrane showed the minimal number of flow voids (23.1±7.0 of >5000 µm2 voids per scan) and was chosen for further analysis. The number of flow voids of >5000 µm2 in healthy paired eyes of CSC patients was statistically significantly higher than in the eyes of healthy individuals (32.7±10.7 and 25.3±8.1 voids/scan, respectively; p=0.022). The number of flow voids of >10000 µm2 was also statistically significantly higher in CSC eyes compared to healthy eyes (5.6±3.3 and 3.5±1.9 voids/scan, respectively; p=0.045). There was no statistically significant difference in total area of the voids between the eyes of healthy individuals and CSC patients (96406.1±3924.5 µm2 and 95395.7 ± 3615.1 µm2, respectively; p=0.42). CONCLUSION: The optimal settings for choriocapillaris imaging on the SOLIX tomograph include 9-µm slab 9 to 18 µm below the Bruch's membrane. Using a 9-µm slab 12 µm below the Bruch's membrane, a substantial difference was found in choriocapillaris perfusion between eyes of healthy individuals and CSC patients.

[OCT visualization of hyporeflective lacuna in the retrolental space]. / OKT-assotsiirovannaya vizualizatsiya giporeflektivnoi lakuny v retrolental'nom prostranstve.

PURPOSE: To investigate the vitreo-lenticular interface and anterior vitreous using high-resolution optical coherence tomography (OCT). MATERIAL AND METHODS: This prospective single-center pilot study included 34 patients (68 eyes) - 6 males and 28 females with a mean age of 58.4±12.0 years (age range 24-81 years). OCT scanning was performed on the spectral domain optical coherence tomography (SD-OCT) device SOLIX (OPTOVUE, USA) in the Full Range AC mode with the following scan parameters: from 14 to 18 mm in horizontal length and 6.25 mm in the axial dimension. To improve the signal-to-noise ratio and increase image clarity of the final scan, averaging of eight simultaneous scans was performed. RESULTS: In all healthy volunteers, hyporeflective retrolental cavities-lacunae were observed in both eyes during visualization of the retrolental space in the horizontal and vertical planes. The median distance from the posterior pole of the lens to the lacuna was 697 µm. The median width of the lacuna was 157 µm. CONCLUSION: To the best of our knowledge, we consider this to be one of the first in vivo visualizations of a previously undescribed structure - hyporeflective retrolental lacuna - using SOLIX high-resolution OCT device. The retrolental lacuna may play the role of a buffer system, or belong to the lymphatic system of the vitreous body and the eye.

[Structural and functional changes in the retina and optic nerve in patients with toxic optic neuropathy caused by acute methanol poisoning]. / Osobennosti strukturnykh i funktsional'nykh izmenenii setchatki i zritel'nogo nerva u patsientov s toksicheskoi opticheskoi neiropatiei na fone otravleniya metanolom.

PURPOSE: To identify the specifics of structural and functional changes in patients with toxic optical neuropathy caused by acute methanol poisoning. MATERIAL AND METHODS: One female patient with toxic optic neuropathy (TON), 2 male patients with partial optic atrophy caused by methanol poisoning, and 1 male patient with methanol intoxication after ethanol containing alcohol use were examined with kinetic perimetry and optical coherence tomography. RESULTS: Patients with TON caused by acute methanol poisoning were observed to have decreasing visual acuity to the extent of complete blindness. OCT follow-up studies revealed thinning of the retinal nerve fiber layer (RNFL) as well as formation of microcysts in the inner retinal layers, destruction of ellipsoid zone and outer segments of photoreceptors. The patient with methanol intoxication after use of ethanol containing alcohol had retained his visual functions; he was found to have microcysts and RNFL thinning during the first few months after the intoxication, but they were within normal range of OCT parameters. CONCLUSION: Patients with TON caused by acute methanol poisoning are common to have optic atrophy with either residual visual functions or complete blindness as well as microcysts formation, structural changes and destruction of the ellipsoid zone and outer segments of photoreceptors. In patient with methanol intoxication after use of ethanol, which is known to be an antidote, complete visual recovery was observed, although some microcystic changes and ganglion cells layer thinning were noted.

[Characteristics of changes in retinal and optic nerve microvascularisature in Leber hereditary optic neuropathy patients seen with optical coherence tomography angiography]. / Osobennosti mikrososudistykh izmenenii setchatki i zritel'nogo nerva u patsientov s nasledstvennoi opticheskoi neiropatiei po dannym opticheskoi kogerentnoi tomografii-angiografii.

PURPOSE: To investigate the features of various parameters of the density of retinal blood vessels, optic nerve head (ONH) and peripapillary region in hereditary optic neuropathy (HON) patients revealed with optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: The study included 29 HON patients divided into three groups based on symptoms duration (less than 1 year; 1-5 years, more than 5 years) and visual acuity (0.5-1.0; 0.04-0.4; 0.03 and lower). Relative macular, optic disc and peripapillary vessel density (VD, %) was assessed by OCTA (xR Avanti, Optovue Inc., USA). RESULTS: Significant progressive VD reduction in superficial capillary plexus (SCP) was detected in all parafovea sectors and in the temporal sector of perifovea over the course of disease progression. No significant differences of these parameters were found in correlation with visual acuity. Patients with VA of 0.5-1.0 turned out to have greater VD in deep capillary plexus (DCP), whereas no differences were found in relation to the duration of HON. A strong significant correlation between the SCP and DCP VD only in central foveal area was revealed in all groups depending on the VA and symptoms duration. Over the course of HON progression, VD in the temporal sector and in temporal segments of superior and inferior sectors has gradually reduced. In patients with VA of 0.5-1.0, the retinal nerve fibers layer (RNFL) thickness in the temporal sector and optic nerve VD was notably greater compared to patients with lower VA. The most significant correlation was established between VA and structural changes (K=0.75, p<0.001) and VD in the temporal sector (K=0.57-0.61, p<0.001). CONCLUSION: The obtained data suggest that derivative microvascular changes play an active role in the clinical progression of the disease.

[Preventive laser treatment of tractional symptomatic retinal flap tears: long-term outcomes]. / Otdalennye rezul'taty profilakticheskogo lazernogo lecheniya traktsionnykh simptomaticheskikh klapannykh razryvov setchatki.

Tractional flap tears are the main cause of the development of regmatogenic retinal detachment (RRD). The main immediate treatment method for it is laser retinal coagulation. PURPOSE: Case monitoring of tractional symptomatic flap tears after laser treatment. MATERIAL AND METHODS: From 2014 to 2019 we observed 119 patients (130 eyes) with peripheral flap (horseshoe) retinal tears in acute posterior vitreous detachment. Laser coagulation of the retina was performed using Navilas 577s (577 nm), OcuLight GL (532 nm). Laser retinotomy of horseshoe tear flap and dissection of overhanging vessels were performed using Nd:YAG-ultra Q Reflex laser (1064 nm) and controlled with RTVue XR Avanti. RESULTS: At the initial examination before the preventive laser coagulation, the following conditions were found: regmatogenous retinal detachment (RRD) - 8 eyes (6.2%), partial hemophthalmus - 29 (22.3%), preretinal hemorrhage - 15 (11.5%), epiretinal membrane - 9 (6.9%), non-full-thickness macular retinal breaks - 6 (4.6%), peripheral changes: retinal holes - 16 (12.3%), tears with operculum - 5 (3.8%), retinal degenerations - 40 eyes (30.8%). Observation for 5 years after laser retinopexy revealed new pathological changes: flap tears - 13 (10.6%); holes - 9 (7.4%); tears with operculum - 5 (4.1%); vitreoretinal tuft - 6 (4.9%); RRD - 3 cases (2.5%). In 16 patients (16 eyes) with horseshoe tear and pronounced vitreoretinal traction, the flap retinotomy was performed, which eliminated the traction component and prevented the development of RRD. CONCLUSION: Follow-up of tractional symptomatic flap tears for 5 years after preventive laser retinopexy revealed the appearance of retinal detachment in 2.5% of cases. Laser retinotomy of horseshoe tear after barrier retinopexy eliminated the traction component and helped prevent the development of RRD.

[Pattern visual evoked potentials and their relation to the peripapillary and retrobulbar blood flow in glaucoma]. / Patternzritel'nye vyzvannye potentsialy i ikh sviaz' s peripapilliarnym i retrobul'barnym krovotokom pri glaukome.

PURPOSE: To examine the relationship between the development of bioelectric response of retinal cell elements to pattern stimulus and the ocular blood flow. MATERIAL AND METHODS: Electrophysiological studies, including pattern-reversal visual evoked potentials (VEP) with large 1 degree (1°) and small 0.25° checks, Color Doppler imaging (CDI) of the retrobulbar vessels, and OCT Angiography in the area of the optic disc and peripapillary retina were performed in 48 patients with initial primary open-angle glaucoma (POAG), 47 patients with advanced POAG, and 42 control subjects. Authors also studied the correlations between VEP values and the parameters used in CDI and OCT-A examination. RESULTS: The most noticeable differences between the study groups were the amplitudes of P100 pattern VEP values for small and large patterns and the OCT-A parameters: Whole-image Disc Vessel Density (widVD), Peripapillary Vessel Density (pVD), Peripapillary Vessel Density Inferior Temporalis (pVD IT). In initial glaucoma, a strong correlation was observed between the amplitude of P100 pattern VEP 1° and pVD IT (r=0.75; p<0.0001); the blood flow rates in ophthalmic artery, central retinal artery, central retinal vein and short posterior ciliary arteries were below normal, while the blood flow in these vessels had statistically reliable correlation with the amplitude of P100 pattern VEP (p<0.05). No correlation was found in patients with advanced stages of glaucoma. CONCLUSION: Pattern VEP is an informative method of glaucoma diagnostics which accuracy can be enhanced by combining it with OCT-A blood flow examination.

[Pattern electroretinogram and macular perfusion in glaucoma]. / Pattern-élektroretinogramma i makuliarnaia gemoperfuziia pri glaukome.

PURPOSE: To study microcirculatory and functional changes in macula in patients with Primary Open-Angle Glaucoma (POAG). MATERIAL AND METHODS: The study included 95 POAG patients and 42 healthy control subjects. Whole en face image vessel density (wiVDRetina) was measured both in fovea and in parafovea using OCT-angiography (OCT-A) by means of SD-OCT AngioVue on Avanti RtVue xR (Optovue Inc., U.S.A.). Macular thickness and parameters of macular ganglion cell complex (GCC) were measured on the same day. Blood flow in the retrobulbar vessels was evaluated by means of Color Doppler Imaging (CDI). Pattern electroretinogram (PERG) was also taken from the study eyes. Correlations between PERG, SD-OCT GCC, macular thickness, and the parameters of OCT-A and CDI were studied. RESULTS: The amplitude of t-PERG P50 decreased from 6.1±1.3 µV in normal eyes to 2.8±1.6 µV (p<0.0001) in early glaucoma and to 2.3±1.5 µV (p=0.93) in advanced stages. Relative vessel density of the capillary bed decreased from 51.3±3.0% in normal eyes to 45.9±5.0% (p<0.001) and to 41.8±5.0% (p=0.023) in early and advanced glaucoma respectively. The parameters of OCT-A and CDI correlated with morphological and functional parameters in normal and early glaucomatous eyes. CONCLUSION: The study revealed reduction of macular microcirculation and decrease of PERG in early glaucoma. Correlations between the circulatory parameters and functional changes were found in early stages of the disease.

[Evaluation of YAG-laser vitreolysis effectiveness based on quantitative characterization of vitreous floaters]. / Otsenka éffektivnosti YAG-lazernogo vitreolizisa na osnove ob''ektivnoi kolichestvennoi otsenki plavaiushchikh pomutnenii v steklovidnom tele.

PURPOSE: To develop methods for evaluating effectiveness of YAG-laser vitreolysis of vitreous floaters. MATERIAL AND METHODS: The study included 144 patients (173 eyes) who had underwent YAG-laser vitreolysis and were under observation from 01.09.16 to 31.01.18. The patients were 34 to 86 years old (mean age 62.7±10.2 years), 28 (19.4%) patients were male, 116 (80.6%) - female. All patients underwent standard and additional examination: ultrasonography (Accutome B-scan plus, U.S.A.), optic biometry (Lenstar 900, Haag-Streit, Switzerland), spectral optical coherence tomography using RTVue XR Avanti scanner (Optovue, U.S.A.) in modes Enhanced HD Line, 3D Retina, 3D Widefield MCT, Cross Line, Angio Retina, and scanning laser ophthalmoscopy (SLO) using Navilas 577s system. Laser vitreolysis was performed using the Ultra Q Reflex laser (Ellex, Australia). RESULTS: This paper presents methods of objective quantitative and qualitative assessment of artifactual shadows of vitreous floaters with spectral optical coherence tomographic scanner RTVue xR Avanti employing an algorithm of automatic detection of non-perfusion zones in modes Angio Retina, HD Angio Retina, as well as foveal avascular zone (FAZ) measurement with Angio Analytics® software. SLO performed with Navilas 577s was used as method of visualizing floaters and artifactual shadows in retinal surface layers prior to surgical treatment and after YAG-laser vitreolysis. CONCLUSION: Suggested methods of quantitative and qualitative assessment of artifactual shadows of the floaters in retinal layers are promising and may prove to be highly relevant for clinical monitoring of patients, optimization of treatment indications and evaluating effectiveness of YAG-laser vitreolysis. Further research of laser vitreolysis effectiveness in patients with vitreous floaters is necessary.

[Macular blood flow in glaucoma]. / Osobennosti makuliarnogo krovotoka pri glaukome.

AIM: to assess macular blood flow in primary open-angle glaucoma (POAG) patients using optical coherence tomography angiography (OCT-A). MATERIAL AND METHODS: The study included 65 POAG patients and 22 age-matched healthy volunteers. Using OCT-A, blood flow parameters (Flow Area, Flow Index, and Vessel Density) were assessed in the para- and perifovea (0.6-2.5 mm and 2.5-5.5 mm, respectively) at the level of both superficial and deep vascular pexuses. Statistical analysis was performed with SPSS version 21 and MASS library of the R language. RESULTS: All the studied parameters were decreased in glaucoma patients as compared to healthy participants: Index superficial parafovea was 0.03±0.01 and 0.04±0.01 (p<0.001), respectively; Index superficial perifovea - 0.02±0.01 and 0.04±0.01 (p<0.001), respectively; Flow superficial parafovea area - 1.57±0.85 mm2 and 2.53±0.53 mm2 (p<0.001), respectively; Index deep parafovea - 0.02±0.02 and 0.03±0.01 (p<0.001), respectively; Index deep perifovea - 0.01 ±0.01 and 0,03±0.01 (p<0.001), respectively; and Flow deep parafovea area 1.02±0.9 mm2 and 1.97±0.82 mm2 (p<0.001), respectively. The differences were statistically significant between glaucoma patients and the controls, but not between glaucoma patients at different disease stages. CONCLUSION: Decreased OCT-A parameters in non-advanced glaucoma indicate an early reduction of blood supply to the macula and explain the involvement of the latter in the pathological process in POAG.

[Analysis of changes in central macular thickness based on optical coherence tomography angiography findings in retinal vein occlusion]. / Izmeneniya tsentral'noi zony glaznogo dna pri retinal'nykh venoznykh okklyuziyakh po dannym opticheskoi kogerentnoi tomografii-angiografii.

AIM: To investigate the relationship between OCT angiography measurements and central fundus changes in patients with retinal vein occlusion (RVO). MATERIAL AND METHODS: The study enrolled 21 RVO patients aged from 55 to 86 years (69.9±2.28 years), including 8 patients with ischemic central RVO (I-CRVO; 73.6±3.4 years on average) and 13 patients with branch RVO (BRVO; 67.6±3.0 years on average). Of the latter, 8 cases were ischemic (I-BRVO) and 5 non-ischemic (NI-BRVO). OCT angiography (OCTA) was performed using RTVue XR Avanti (Optovue, USA) tomograph in the Angio Retina mode. RESULTS: A direct correlation was found between visual acuity and the degree of macular perfusion when assessing a scanning area of 6x6 mm. Having compared the degree of perfusion in groups, we have revealed that it changed significantly regardless of the size of the area scanned and the radius of the region of interest. Patients with ischemic CRVO demonstrated the lowest perfusion (Flow Area). As to ischemic and non-ischemic BRVO patients, the difference between them was only noticed with small scanning area (3x3 mm). Another statistically significant difference was shown for the blood flow index in the I-CRVO and NI-BRVO groups with scan area of 3x3 mm. Of 8 I-CRVO patients, 4 demonstrated areas of hypoperfusion within both superficial and deep vascular plexuses, while the other 4 - within the deep plexus only. In the I-BRVO group, 7 patients had hypoperfusion within both superficial and deep vascular plexuses and just 1 - within the deep plexus. In the NI-BRVO group all 5 patients had hypoperfusion of deep layers with no involvement of the superficial plexus. CONCLUSION: The value of information on vascular perfusion in all layers of the central retina provided by OCT angiography is very high, which makes it useful for the detection of microvascular abnormalities in patients with retinal vein occlusions.

[Optical coherence tomography angiography in the diagnosis of neovascular age-related macular degeneration].

AIM: to determine optical coherence tomography (OCT) angiography signs of classic and occult choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD) and evaluate their information value in monitoring the effect of anti-VEGF therapy. MATERIAL AND METHODS: The study enrolled 76 patients (87 eyes), including 68 patients (72 eyes) with wet AMD and 8 patients (15 eyes) with no signs of neovascularization. All patients underwent spectral-domain OCT, OCT angiography, and fluorescein angiography (FA). OCT angiography was used to evaluate neovascular networks in terms of their location, shape, size, and extent of visualization. Sensitivity and specificity of the method were assessed separately in a group of 37 CNV eyes and 15 unsuspicious eyes, specific findings at FA being the main diagnostic criteria. To determine the information value of OCT angiography in monitoring the effect of intravitreal ranibizumab therapy, 9 patients (9 eyes) were selected, in whom the exam was performed the day before the injection and then at days 3, 10, 17, 24, and 31. RESULTS: The patients were divided into two groups. Group 1 consisted of 43 eyes with occult CNV, group 2--of 29 eyes with classic CNV. Neovascular loops underneath the retinal pigment epithelium were found in 76.74% of occult CNV cases. In patients with classic CNV, the neovasculature was clearly visible in 82.76% of eyes, loop-like and tree-like networks occurring with similar frequency (51.72% and 42.28% respectively). OCT angiography results obtained prior to and following ranibizumab injection revealed a change in not only the size of neovascularization, but also the density, thickness, and branching pattern of newly formed blood vessels. Sensitivity and specificity of OCT angiography has been shown to be 89.2% and 93.3% respectively. CONCLUSION: OCT angiography enables diagnosis of both classic and occult choroidal neovascularization in patients with AMD as well as dynamic assessment of the size of the neovascular complex during anti-VEGF treatment. The method has high sensitivity and specificity.

[Rare case of vitreoretinal lymphoma].

Primary intraocular lymphoma (PIOL) is a primary central nervous system lymphoma subtype. The article presents a case of bilateral vitreoretinal lymphoma in a functionally monocular 68-year-old woman, whose ocular manifestations developed prior to multiple primary lymphoma of the brain, thus, impeding the diagnosis. Stereotactic radiotherapy enabled stabilization of the process and did not affect visual functions.

[Morphological changes in retina and optic nerve head in patients with Leber's hereditary optic neuropathy].

OBJECTIVE: To study morphological changes of the macula and the peripapillary nerve fiber layer in patients with Leber's hereditary optic neuropathy (LHON). MATERIAL AND METHODS: A total of 21 patients (40 eyes) with LHON and 17 healthy volunteers (33 eyes) of the control group were assessed. Optical coherence tomography (OCT) on RTVue-100 for retina and optic nerve head assessment was performed in all cases. RESULTS: Thinning of the inner retinal layers in nasal and inferior parafoveal sectors takes place in the early acute period of the disease and then spreads to the rest of the macular area. The retinal nerve fiber layer (RNFL) in the early acute period is of more thickness in temporal, inferior, and superior sectors in comparison to controls, but later gradually becomes thinner, especially in the temporal sector. In the late period significant peripapillary RNFL thinning is present in all sectors. CONCLUSION: OCT reveals certain structural changes in the macular area and the peripapillary RNFL that are characteristic of Leber's hereditary optic neuropathy and together with clinical presentation can substantiate the diagnosis.

[Optical coherent tomography in diagnosis of peripheral retinal breaks].

The purpose of our study was to develop an optimal method of peripheral retinal breaks visualization and determine the presence of vitreoretinal traction using optical coherence tomography (OCT). A total of 152 patients (176 eyes) with peripheral retinal breaks were assessed, among them 57 men and 95 women, aged from 18 to 76. To visualize retinal periphery we used RTVue-100 optical coherent tomograph (USA). Photoregistration was done with Nikon NF-505 fundus camera (Japan). All patients were examined with Goldmann lens. OCT application enabled us to determine structural features and configuration of peripheral retinal breaks, the presence of vitreoretinal traction, and morphometric parameters of the defects: the average length and height, retinal thickness in three standard points (prior to the break, at its edge and at the bottom), and also the extent of vitreoretinal fusion and local detachment of retinal neuroepithelium (NE). Two groups of peripheral retinal tears were formed: group I (23 eyes)--retinal flap tears and group II (153 eyes)--perforated breaks. Optical coherence tomography is a highly informative method which enables in vivo evaluation of structural and morphometric characteristics of retinal defects and vitreoretinal fusion, as well as possible vitreoretinal traction and subclinical detachment of the retina. Its use will ensure proper documentation of study results and also provide the possibility to determine indications for laser and surgical treatment and perform a late follow-up.

Photoplethysmographic Imaging of Hemodynamics and Two-Dimensional Oximetry.

The review of recent papers devoted to actively developing methods of photoplethysmographic imaging (the PPGI) of blood volume pulsations in vessels and non-contact two-dimensional oximetry on the surface of a human body has been carried out. The physical fundamentals and technical aspects of the PPGI and oximetry have been considered. The manifold of the physiological parameters available for the analysis by the PPGI method has been shown. The prospects of the PPGI technology have been discussed. The possibilities of non-contact determination of blood oxygen saturation SpO2 (pulse saturation O2) have been described. The relevance of remote determination of the level of oxygenation in connection with the spread of a new coronavirus infection SARS-CoV-2 (COVID-19) has been emphasized. Most of the works under consideration cover the period 2010-2021.

Federal medical biological agency of Russia's efforts to support Russian athletes during COVID-19 outbreak.

This paper dwells upon COVID-19-related efforts of the Center for Sports Medicine, Federal Medical and Biological Agency of Russia. The Agency has the following precautions in place: regular polymerase chain reaction (PCR) testing of athletes and staff; double PCR testing before going to training camps or medical examinations; isolating athletes and their traceable contacts when COVID is suspected; observation and isolation wards set up at training camp venues. Athlete vaccination has begun. Athletes are provided online advice on health, diet, and exercising plus special care for chronically ill athletes and remote psychological counseling. Athletes recovering from COVID-19 are offered rehabilitation programs and doctor-supervised return to training. Specialists of the Research Department at FMBA's Center for Sports Medicine carried out a research dedicated to the prevalence of COVID-19 and different variants of its course in Russian athletes. The study period lasted from March to December 2020. A total of 27,438 records were analyzed. In May, June, July and August 2020, the percentage of positive PCR tests for athletes was significantly lower than the nationwide percentage at p < 0.05, Pearson's chi-squared test. However, the differences were nullified by September-October. The disease was mild or asymptomatic in most patients. Athletes of summer sports were found to be most likely to contract COVID-19.

Thermography-based blood flow imaging in human skin of the hands and feet: a spectral filtering approach.

The determination of the relationship between skin blood flow and skin temperature dynamics is the main problem in thermography-based blood flow imaging. Oscillations in skin blood flow are the source of thermal waves propagating from micro-vessels toward the skin's surface, as assumed in this study. This hypothesis allows us to use equations for the attenuation and dispersion of thermal waves for converting the temperature signal into the blood flow signal, and vice versa. We developed a spectral filtering approach (SFA), which is a new technique for thermography-based blood flow imaging. In contrast to other processing techniques, the SFA implies calculations in the spectral domain rather than in the time domain. Therefore, it eliminates the need to solve differential equations. The developed technique was verified within 0.005-0.1 Hz, including the endothelial, neurogenic and myogenic frequency bands of blood flow oscillations. The algorithm for an inverse conversion of the blood flow signal into the skin temperature signal is addressed. The examples of blood flow imaging of hands during cuff occlusion and feet during heating of the back are illustrated. The processing of infrared (IR) thermograms using the SFA allowed us to restore the blood flow signals and achieve correlations of about 0.8 with a waveform of a photoplethysmographic signal. The prospective applications of the thermography-based blood flow imaging technique include non-contact monitoring of the blood supply during engraftment of skin flaps and burns healing, as well the use of contact temperature sensors to monitor low-frequency oscillations of peripheral blood flow.

[New technological means in medical diagnosis]. / Novye tekhnologicheskie sredstva v meditsinskoi diagnostike.

Diagnostic methods using a Pulsar radar measuring computer unit have been developed. The methods are based on the contactless recording of respiratory parameters and pulse and they evaluate human body's functions in real time from the measurements of the duration of cardiac rhythms and calculate the differential function of their distribution and the spectrum of a cardiac rhythmogram.