[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.

[Current approach and the role of laser photocoagulation in the treatment of retinal vein occlusions]. / . Sovremennye podkhody i mesto lazernoi koaguliatsii v lechenii okkliuzii ven setchatki.

Despite the emergence of new approaches in the treatment of retinal vein thrombosis and post-thrombotic complications, namely, intravitreal pharmacotherapy and surgical treatment, laser photocoagulation continues to play a significant role in the management of patients with this pathology. Although the method of laser photocoagulation has been used for quite a long time, different views exist on its indications and execution in specific clinical situations. At that, not all opinions regarding the use of laser photocoagulation in thrombosis are based on convincing clinical studies. The aim of this work was to summarize current literature data on the use of laser photocoagulation in the integrated treatment of retinal vein occlusions and, also, to show which aspects of the treatment of thromboses can be considered well-established and reasonable and which remain a subject of debate.

[Dynamics of electrophysiological parameters of the retina after surgical treatment of idiopathic macular hole]. / Dinamika élektrofiziologicheskikh parametrov setchatki posle khirurgicheskogo lecheniia idiopaticheskogo makuliarnogo otverstiia.

AIM: to study the dynamics of recovery of electrophysiological parameters of the retina after surgical treatment of idiopathic macular hole (IMH) and to assess their relevance to functional prognosis of the operation. MATERIAL AND METHODS: The study included 118 patients (120 eyes) examined before and after successful IMH surgery. The patients underwent electroretinography (Ganzfeld and multifocal), static computed perimetry, and optical coherence tomography. They were also tested for the electrical sensitivity of the retina, lability of the visual analyzer, and critical fusion frequency. Postoperative functional parameters of the retina (electrophysiological included) were followed up at 1-2, 5-6, and 12-plus months and then compared to those obtained before surgery. Parameter dynamics, relationships, and the prognostic value of particular indicators were of interest. RESULTS: It was found that after successful restoration of retinal anatomy, functional parameters of the retina gradually improve and reach their maximum at 3 to 12 months, however, remain below the normal range in all cases. In 58 cases, postoperative visual acuity was 0.5 or higher (regarded as 'high postoperative visual acuity' - the HPVA group) and was accompanied by high density of foveal biopotential and foveal light sensitivity. In the HPVA group, the majority (62%) were patients with preoperative 'shift phenomenon' (a shift of the maximum of bioelectric potential from the fovea to parafovea and perifovea, its amplitude and density being supernormal for these retinal regions). CONCLUSION: Changes in electrophysiological and other functional parameters of the retina can be detected within 3-12 months after successful IMH surgery. Their recovery is not full and goes with a delay relative to restoration of retinal structure. The probability of high functional result of the operation, which includes an increase in visual acuity, foveal light sensitivity, and amplitude and density of foveal biopotential, is higher in patients with biopotential shift at baseline.

[Electrophysiological parameters of the retina in idiopathic macular hole]. / Elektrofiziologicheskie pokazateli setchatki pri idiopaticheskom makulyarnom otverstii.

AIM: To investigate the nature and range of electrophysiological disturbances in idiopathic macular hole (IMH) and establish their relationship with structural parameters of the retina. MATERIAL AND METHODS: The study included 249 patients (280 eyes) with IMH. All of them underwent ganzfeld and multifocal electroretinography (ERG), optical coherence tomography, and evaluation of retinal electrical sensitivity and analyzer lability. The results were then compared to those of non-IMH patients (196 paired eyes) and controls (25 people, 49 eyes). RESULTS: Multifocal ERG findings prove that IMH is always associated with significant changes in bioelectrical potential of the central retina. In 62% of cases its decreased density and extended latency were registered in not only the fovea, but also the para- and perifovea. In 8% of cases the changes involved everything within a 30-degree area of the central retina. In 30% of cases the maximum bioelectric potential was found to have shifted from the centre to para- and perifovea, its amplitude and density being supernormal for these regions (shift phenomenon). A weak correlation between electrophysiological parameters and retinal thickness around the hole has been also established. CONCLUSION: Of all methods used to assess retinal function in IMH, multifocal ERG is the most informative. In 100% of cases foveal biopotential is sharply reduced in density and disfigured. In 70% of cases these changes spread outside the fovea.

[Intraocular lens power calculation in silicone-filled eyes].

AIM: to evaluate the accuracy of different modified methods for axial length (AL) measurement in silicone-filled eyes. MATERIAL AND METHODS: The study was conducted in a group of 60 patients (60 eyes) with silicone oil tamponade (Oxane 1300 cst). Axial length measurements were taken using IOL Master optical coherence biometry ('silicone-filled eye' mode) and modified A-scan ultrasound biometry (velocity of ultrasound passing through the vitreous body set at 980 m/s and 1000 m/s). After phacoemulsification and silicone oil removal, AL measurements were repeated on same devices switched to standard pseudophakia modes. The results were then compared to those obtained in modified modes before the surgery. RESULTS: Preoperative axial lengths measured by A-scan at 980 m/s tended to be 0-1.5 mm (the median of 0.52 mm) shorter than those obtained after silicone oil removal. With 1000 m/s ultrasound velocity the error was much less--from 0 to 0.5 mm (the median of 0.15 mm). As for preoperative ALs by IOL Master in the 'silicone-filled eye' mode, they were 0-1.2 mm (the median of 0.3 mm) longer than postoperative ones. CONCLUSIONS: In cases of impossibility or inaccessibility of optical biometry, measurements taken with an A-scan device set at 1000 m/s are sufficient. The true AL of an eye with silicone oil tamponade falls somewhere between the values obtained with 1000 m/s ultrasound and IOL Master in the 'silicone-filled eye' mode.

[Combined transscleral and transpupillary thermotherapy in large vasoproliferative retinal tumors].

Three cases (two patients) of large vasoproliferative retinal tumor treatment by an original method, which includes intraoperative non-contact transscleral thermotherapy and subsequent transpupillary thermotherapy, are described. Positive anatomical results were achieved in all three cases.

[Intraocular pressure and ocular blood flow features intravitreal infection of anti-vascular endothelial growth factor agents].

OBJECTIVE: to investigate intraocular pressure (IOP) and ocular blood flow (OBF) changes as well as the individual normal range of IOP in patients with age-related macular degeneration (AMD) with or without concomitant glaucoma after intravitreal anti-vascular endothelial growth factor (VEGF) therapy. MATERIAL AND METHODS: Group 1 included 34 patients (34 eyes) with AMD and no glaucoma, group 2-34 patients (34 eyes) with both AMD and glaucoma. In all patients the IOP and OBF were measured (with Ocular Blood Flow Analyzer) and the individual normal range of lOP calculated before the treatment, on the third day after the injection and at the 1-month follow-up visit. Statistical analysis was performed by STATISTICA 10. RESULTS: In group 1 there were no significant changes in ocular blood flow at different times after ranibizumab injection. In group 2 a considerable decrease in OBF was detected 1 month after the injection (p<0.001). In group 1 the intraocular pressure was at the same level before and after the treatment. In group 2 the IOP significantly decreased on the third day after the anti-VEGF injection (p=0.03) but was back to the initial level in 1 month. The individual normal range of lOP, when calculated on the third day after the injection, appeared to be much lower than before due to a moderate decrease in both IOP and OBF. At the 1-month follow-up the individual normal range of IOP was back to initial values in non-glaucoma patients but remained low in the glaucoma group due to reduced OBF. CONCLUSION: The established decrease in the individual normal range of IOP in the late period after an anti-VEGF injection should be taken into account when managing patients with both AMD and glaucoma.

[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.

[Potentialities of immunofluorescence in examination of retinal vascular system and epiretinal proliferation (experimental study)].

An immunofluorescent method of examination of retinal vascular system and epiretinal proliferative tissue removed during a transciliary surgery has been developed. The proposed method possesses certain advantages, i.e. high-quality visualization of the vascular system in total mounts, particularly, of the capillary loops and fine vascular terminals, the possibility to use specific immunohistochemical markers to identify all kinds of present cells (glia, endothelium, neurons) and evaluate their proliferative activity.

[Pathogenic features and treatment options of different diabetic retinopathy stages].

An operative classification and up-to-date options of diabetic retinopathy management are presented in the article.

[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.

[Analysis of factors causing peripheral visual field defects after vitreomacular surgery].

As a result of the study analysis of potential causes of visual field defects (VFD) after vitreomacular surgery is performed. 110 cases are enrolled in the study: 81 patient with macular hole and 29 patients with epiretinal fibrosis. Correspondence of VFD to position of irrigation port including unusual inferior-nasal position was revealed as well as VFD absence in epiretinal fibrosis operated without air pump. VFD did not appear after lowering of air pump pressure by 15-20 mmHg. The cause of VFD after vitreomacular surgery is a mechanical damage of internal retinal surface by directed air/gas jet after total fluid exchange with too high pressure in an air pump. This complication is an easily preventable iatrogenic effect and may serve as one of quality criterion for this treatment procedure.

[Treatment of retinal detachment in optic nerve pit].

Clinical presentation, pathogenesis and treatment of optic nerve pit are reviewed. Treatment options of central retinal detachment in optic nerve pit known since 1882 and still used are discussed.

[Pupillary reactions and eye hemodynamics in patients with diabetes mellitus with different glycemic levels].

Pupillary reactions and hemodynamic parameters in the ophthalmic and central retinal arteries were studied in patients with types 1 and 2 diabetes mellitus. The pupillary dilatation test in the dark and 2.5% irifrin and 1% mydriacyl tests revealed a reduction in the papillary dilatation amplitude in hyperglycemia in patients with diabetic retinopathy. The amplitude of pupillary dilatation did not change during all pupil reactions in patients without diabetic retinopathy with a glycemic gradient. Pupillary dysfunction was detected in patients with diabetic retinopathy, which is a poor predictor for microangiopathy. Color Doppler mapping is a technique for studying blood flow, which is widely used in most of research institutions now. The procedure for studying the ocular microcirculatory bed in relation to blood glucose levels is an innovation in examining eye hemodynamics in patients with diabetes mellitus.

[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.

[Multifocal studies of visual functions in the diagnosis of diseases of the ocular neurosensory apparatus].

The paper presents the results of using the current multifocal studies of visual functions in patients with various diseases of the retina (detachment, tapetoretinal abiotrophy, macular foramen). It provides evidence for the high correlation of changes detectable in these patients by statistical computer-assisted perimetry and multifocal electroretinography. The implication of comprehensive application of these techniques to the diagnosis and differential diagnosis of ocular neurosensory apparatus diseases and to the functional monitoring and evaluation of treatment has been ascertained.

[Antiangiogenic therapy for choroidal neovascularization induced by age-related macular degeneration (preliminary communication)].

Specific antiangiogenic therapy for exudative age-related macular degeneration (AMD) aims at suppressing the growth of choroidal neovascularization. Bevacizumab, an antibody to vascular endothelial growth factor, is one of the agents that specifically inhibit angiogenesis. The results of using bevacizumab in choroidal neovascularization induced by AMD are analyzed. Bevacizumab was administered into the vitreous body of 56 patients (60 eyes) in a dose of 1.25 mg; its injections were repeated if the need arose in disease recurrence. The follow-up time was 6 to 12 months. Following 6 months, visual preservation not below the baseline level was noted in 86% of cases; in this period a significant visual improvement was stated in 46% of cases. Fluorescence angiography showed decreased dye leakage in most cases, which correlated with the lower retinal thickness revealed by optical coherence tomography. There were no serious complications. Intravitreal administration of bevacizumab is the method of choice in treating exudative AMD and requires further investigation.

Proliferative activity of retinal vascular cells in newborn rat at different oxygenation modes.

We evaluated the relationship between the percentage of oxygen in inhaled air and alternation of this parameter and proliferative activity of cells in retinal vessels of normal newborn rats. The relationships between these parameters and the mean diameter of retinal vessels were evaluated. The study was carried out on total retinal preparations and tangential sections of the retina by the immunoperoxidase and immunofluorescent methods. Hypoxia and hyperoxia significantly suppressed proliferative activity, while alternation of hyperoxia and normoxia significantly increased both proliferative activity of vascular cells and the mean diameter of retinal vessels.