[Modern concepts of pathogenesis of diabetic retinopathy]. / Sovremennye kontseptsii patogeneza diabeticheskoi retinopatii.

This literature review presents modern view on the pathogenesis of diabetic retinopathy (DR) paying particular attention to the molecular mechanisms leading to its development, as well as the manifestations of retinal neurodegeneration in such patients. Assessment of this condition and its clinical manifestations makes it possible to diagnose DR at the stage of absent initial vascular changes. Investigating the neurodegeneration mechanisms could supplement the existing understanding of the disease pathogenesis and could possibly help find new ways of treatment and prevention of DR.

[Viscodissection with staining of epiretinal membranes in surgery of proliferative diabetic retinopathy]. / Viskodissektsiya s kontrastirovaniem epiretinal'nykh membran v khirurgii proliferativnoi diabeticheskoi retinopatii.

PURPOSE: To develop a method of viscodissection involving staining of epiretinal membranes, and to evaluate its efficacy and safety in surgical treatment of proliferative diabetic retinopathy (PDR). MATERIAL AND METHODS: The study included 30 patients with type 1 diabetes mellitus and PDR with tractional retinal detachment (TRD). All patients were divided into two groups. In the first (main) group, at the initial stages of the operation, viscodissection with staining of epiretinal structures was performed, followed by segmentation and removal of membranes; in the second (control) group, segmentation and removal of membranes was performed using a vitreotome and endovitreal forceps. RESULTS: During the follow-up, all patients showed positive trends of morphological and functional indicators. While the number of intraoperative stages was the same in both groups, the total operation time in patients of the main group was significantly lower (p≤0.001) than in patients of the control group (main - 41.3±2.8 min; control - 53.8±6.2 min). With equal number of posterior hyaloid membrane to inner limiting membrane (PHM to ILM) fixation points in both groups, iatrogenic retinal rupture occurred significantly less frequently in patients of the main group (main - 0.6±0.7, control - 3.1±2.9) (p≤0.001). In this regard, among the patients of the control group, in the overwhelming majority of cases, it was necessary to use a silicone oil tamponade (60%) or gas-air mixture (33%), while in the first group the main postoperative media were sterile BSS solution (73%) and gas-air mixture (27%).

[Current trends in the screening for diabetic retinopathy]. / Sovremennye tendentsii skrininga diabeticheskoi retinopatii.

The incidence of diabetes in the world is steadily increasing, and so is growing the number of cases of vision loss and blindness resulting from diabetic retinopathy (DR). This pathology is asymptomatic in the initial stages, but only the early treatment can be effective. In this regard, DR screening is an important and actual problem. This article reviews the principles, criteria, and problems of the currently run DR screening programs that are based on digital photography of the fundus. Special attention is paid to the displayed biomarkers and their role in DR screening. Various research methods are described, such as fluorescence angiography, optical coherence tomography, optical coherence tomography agniography, laser scanning ophthalmoscopy, which can be used to visualize pathological changes in the retina associated with DR. These changes were considered as potential screening biomarkers for DR. The review also describes new areas of screening based on telemedicine, artificial intelligence, and mobile photo-registering devices.

[Results of laser confocal microscopy of the cornea in viral uveitis (a preliminary report)]. / Rezul'taty lazernoi konfokal'noi mikroskopii rogovitsy pri virusnykh uveitakh (predvaritel'noe soobshchenie).

Herpesviruses involve neurotropic activity (they affect nerve cells) and have the ability to induce an immune response (a special tropism for immune tissue), which provides a valid reason for studying the possibilities of visualizing nerve fibers of the cornea and Langerhans cells (LC) in viral uveitis (with prospective applications in early diagnosis). PURPOSE: To evaluate the results of laser corneal confocal microscopy (CCM) in viral uveitis of varying localization. MATERIAL AND METHODS: The main study group included 23 patients (23 eyes) diagnosed with unilateral herpesviral uveitis (chorioretinitis), the patients' age varied from 18 to 79 years. The control group comprised 19 healthy volunteers (38 eyes) aged 20 to 75 years. In addition, the paired eyes of the main group patients were examined. In all patients, standard ophthalmologic examination was complemented with CCM performed on the HRT III device with a corneal module, followed by analysis of the course and structure of corneal nerve fibers (CNF) using copyrighted software Liner 1.2. CONCLUSION: The preliminary results achieved in this study outline the prospects for further research on the state of cornea (in particular, changes in the course and structure of CNF, and the presence of dendritiform cells of Langerhans) with laser CCM in patients with uveitis of various etiologies. These morphological changes also has potential use as diagnostic markers of inflammation of the uveal tract. The main criteria for assessing the state of cornea in viral uveitis include the following: increased tortuosity of CNF, increase in the number and size of Langerhans cells. Further research - in particular, studying the integrated use of diagnostic methods necessary for the verification of viral uveitis, as well as detailed analysis of the history and clinical picture of the disease - is required to substantiate the inclusion of laser confocal microscopy method in the algorithm for the diagnosis of viral uveitis.

[The state of ocular neurosensory apparatus in diabetes mellitus]. / Sostoianie neirosensornogo apparata glaza pri sakharnom diabete.

Diabetes mellitus is one of the most common chronic diseases in the world. Among its late complications that can lead to disability is diabetic neuropathy (DN). Patients diagnosed with DN often also have diabetic retinopathy (DR). According to available data, DR prevalence ranges from 30 to 60%. For a long time, DR has been considered a microvascular disease. However, more data has been emerging recently that indicates the presence of other components in the pathophysiology of DR. Neurodegenerative changes in the retina can be detected in patients with diabetes mellitus before clinical signs of diabetic retinopathy appear. Accumulation of extracellular glutamate, oxidative stress, reduction of neuroprotective factors synthesized by the retina are all believed to lead to neuronal apoptosis and glial cell dysfunction. This cascade of reactions subsequently causes disruption of the hematoretinal barrier and damage to neurovascular apparatus of the retina. This results in the defeat of capillaries of the retinal vascular system, which is consistently characterized by the loss of pericytes and the formation of unperfusable capillaries. The concept of neurodegeneration being an early component of DR provides an opportunity to explore alternative therapies to prevent the onset of vision loss in diabetes mellitus.

[Field of view changes after vitreomacular surgery: a treatment quality criteria].

The study enrolled 177 patients that had been admitted to the Research Institute of Eye Diseases of the Russian Academy of Medical Sciences for diagnostics and treatment - 134 patients with idiopathic macular hole and 43 patients with epiretinal fibrosis. All vitreomacular surgeries were performed between 2005 and 2011. Visual field defects were seen in all groups and were classified as either peripheral or paracentral, or concentric. The groups differed by the rate and the localization of the visual field defects. A direct relation between the severity of iatrogenic retinal damage, the extent of postoperative retinal thinning and the presence/type of visual field defects was established. Causes and risk factors of visual field loss after vitreomacular surgery have been identified and analyzed. Preventive measures for this complication have been proposed. Treatment efficacy varied depending on the causes. Acute peripheral visual field loss--"tunnel phenomenon"--as a result of significant iatrogenic local retinal damage during vitreomacular surgery has been described.

[Vitrectomy effect on ocular hydrodynamics in proliferative diabetic retinopathy and nonvascular pathology].

The goal of the study was to determine vitrectomy effect on ocular hydrodynamics. Patients were divided into 2 groups: patients with diabetes mellitus (DM) were enrolled in the 1st group, indications for vitrectomy were vitreous hemorrhage or diabetic macula edema. The 2nd group included patients without DM, indications for vitrectomy were macula hole, epiretinal fibrosis. Electronic tonography was used to measure the main ocular hydrodynamic parameters before and 2-12 months after the surgery. Though intraocular pressure (IOP) increased after vitrectomy in all patients, the true IOP was normal in the majority of them (60%) and did not require medical correction. In the rest of cases IOP increase required medical treatment: in 23% during 1 month, in 11% during 6-12 months. In subsequent follow-up during 2 years no glaucoma signs were revealed.

[Surgical treatment policy using recombinant prourokinase for submacular hemorrhages].

An immunofluorescence technique was used to study the transretinal penetration of intravitreal fibrinolytic agent Hemase (a recombinant urokinase) in an experiment on 4 rabbit eyes. Hemase (54 kD) was proved to be able to penetrate across all retinal layers 2 hours after intravitreal administration. The efficacy of Hemase was tested in the treatment of submacular hemorrhages (SMH) of various etiology. Thirteen patients with SMH associated with age-related macular degeneration or ophthalmic injury were enrolled in the study. Hemase 500 IU was intravitreally injected 24 hours before pneumatic dislocation of SMH in 10 patients. In 3 patients with massive SMH, the proposed vitrectomy procedure was employed, by epiretinally injecting the fibrinolytic agent under a gas bubble, followed by drainage of the subretinal space. The operation was ended, by administering air and Hemase, and then by putting the patient in the supine position for 3-4 hours, thereafter his/her position was recommended to be changed to the prone position to realize the mechanism of pneumatic dislocation. The studies suggest that pneumatic SMH dislocation in combination with Hemase administration permits visual acuity to be increased in 80% of cases. The efficiency of manipulation and the functional outcome of treatment depend on the etiology of hemorrhage. The proposed vitrectomy technique using Hemase reduces neuroepithelial injury, effectively drains SMH, and dislocates its remnants from the foveal area.