PURPOSE: Experimental comparative analysis of hystomorphology associated with different ways of fibrosis prevention in the bleb zone after glaucoma surgery. METHODS: Experiments were conducted on rabbits with approximate weight up to 2.5 kg both male and female (12 animals, 12 eyes). In the first group the rabbits underwent penetrating deep sclerectomy (PDS) with subsequent application of mitomycin C (5 rabbits, 5 eyes). In the second group PDS was performed with Xenoplast (Transkontakt, Moscow, Russia) collagen drainage implantation under the scleral flap (5 rabbits, 5 eyes). The third or control group included 2 rabbits (4 eyes) that underwent PDS with no modifications. Follow-up period lasted for 2 months in all groups. RESULTS: Early postoperative period was characterized by the formation of high filtration blebs in all groups. Filtration surgery with mitomycin C application resulted in high thin-walled avascular bleb formation. In all rabbits of group 1 after 2 months the filtration area gradually decreased in size and lost bleb appearance, replaced by a cystoid formation corresponding with the area of previous mitomycin C application. According to histological examination, the blebs in the comparison group were filled with loose, porous tissue with a minimal amount of connective tissue cellular elements. A formation of separate vessels was noted, which was indicative of their low functional consistency. The sclera located under the filtration bleb consisted of well-defined collagen fibers, more structured than the sclera in the comparison groups, which can be attributed to the impact of drainage on the collagen fibers that constitute the mechanical basis of the scleral tissue. CONCLUSION: Cytostatics, while inhibiting the regeneration, apparently do not affect the remodulation processes. The implantation of collagen drainage containing collagen type I prevents scarring of the operation site and at the same time prolong the effect of glaucoma surgery by helping neutralize the process of eye tunic remodulation associated with the formation of thin-walled capsules impermeable to fluid.

PURPOSE: To assess the influence of cord blood nucleated cells intravenous infusion on visual functions state in patients with glaucomatous optic neuropathy. METHODS: 21 patients (27 eyes) with advanced primary open-angle glaucoma and normal intraocular pressure were included into the study. Group I included 11 patients (16 eyes) with high central visual acuity (over 20/40). Group II comprised 4 patients (5 eyes) with visual acuity around 20/200. Group III consisted of 6 patients (6 eyes) with residual visual functions. All patients underwent complex ophthalmological examination including viso-metry, tonometry with bidirectional applanation method, standard static perimetry (Humphrey Field Analyzer II), threshold of retinal electric sensitivity and lability of the visual analyzer and the critical frequency of flickering fusion (Lametesk). RESULTS: Cord blood nucleated cells tolerability remained good during the whole follow-up period. A decrease in IOP level by the second week of infusion therapy was revealed in all groups. By months 3 and 6 patients in groups I and II presented with a statistically significant positive dynamics in vision fields. Post treatment electrophysiological examination showed results stabilization in all patients of group II. Patients in group III lacked spatial vision, but despite initial grave changes in visual analyzer, all electrophysiological examination indices remained stable. CONCLUSION: Complex therapy with cord blood nucleated cells helps slow the progression of glaucomatous optic neuropathy.

PURPOSE: To compare IOP measurements with transpalpebral IGD-03 device, Maklakov's tonometer and bidirectional applanation of the cornea in glaucoma patients and suspects. METHODS: The study included 70 patients with primary open-angle glaucoma and glaucoma suspects aged from 41 to 89 years. 92 eyes had hypotensive treatment. IOP measurement with bidirectional applanation of the cornea (Ocular Response Analyzer), transpalpebral tonometry (IGD-03 device) and contact applanation tonometry (Maklakov's tonometer, 10 g) were performed in all patients consistently. RESULTS: Mean IOP, measured with different tonometers, was comparable considering the calibration details: IOPcc - 18.5+5.7 mm Hg, IOPg - 17.5+5.5 mm Hg, applanation tonometric IOP - 22.2+4.3 mmHg and transpalpebral IOP - 20.9+4.2 mm Hg. It is possible that patient's position during measurement had affected results. All IOP measurements were directly strongly correlated with each other (r>0.7). We discovered diagnostic value of all devices, statistically normal IOP was revealed in 12.8% cases with IGD-03, in 14.3% - with Maklakov's tonometer and in 28.6% cases of IOPcc measurements. CONCLUSION: Diagnostic value of transpalpebral tonometry was equal to Maklakov's applanation tonometry.

PURPOSE: To determine the effect of Ahmed valve implantation in refractory glaucoma of various genesis within a 3-year timeframe. METHODS: The study included 116 patients (121 eyes) with refractory glaucoma. Patients' age ranged from 20 to 87 years (62.71 ±14.25). Mean intraocular pressure (IOP) before the operation was 42.7+0.9 mmHg. Ahmed valve implantation results were evaluated based on the following criteria: IOP, visual function dynamics, the need for additional medical therapy and reoperation, intraoperative and postoperative complications development. Patients were examined on days 1-8 after the surgery and in 1, 3, 6, 12, 24 and 36 months. RESULTS: According to our survey, absolute and relative hypotensive effect were, respectively, 71.9% (87/121) and 84.3% (102/121) in 1 year after the surgery; 66.9% (81/121) and 80.9% (98/121) - in 2 years after the surgery; 62% (75/121) and 77.7% (94/121) - after 3 years of follow up. There was a statistically significant postoperative IOP reduction within the group compared to the original data (X²=323.3520, pp=0.00000). Postoperative complications developed in 30.5% (37/121) of cases. Number of antiglaucoma medications used before and after surgery decreased from 2.6+0.2 to 1.1+0.4 (Z=4.46, pv=0.00008). The best result was observed in patients with previously operated primary open-angle glaucoma (88.1% - 1 year, 85.7% - 2 years, 83.3% - 3 years), the worst - in the neovascular secondary glaucoma group (79.4% - 1 year, 71.4% - 2 years, 66.7% - 3 years). Lack of postoperative effect during the 3-year follow-up was noted in 22.3% (27/121) of cases. CONCLUSION: Ahmed valve implantation in patients with refractory glaucoma provides a long-term sustainable hypotensive effect in 77.7% of cases within 3 years after the surgery. The patients with an implanted valve require regular follow-up by an ophthalmologist due to a high risk of postoperative complications both in early and long-term postoperative period.

PURPOSE: To develop an optimal device of our own design to expand and maintain Schlemm's canal volume and experimentally assess its application in practice. METHODS: To conduct the study we selected an equiatomic alloy composition of nickel and titanium - Nitinol. The implant is a hollow tube with multiple perforations of different sizes. Its outer diameter is 245 mkm, internal -150 mkm. Implant is shaped like an open ring with a diameter of 11 mm. We used Glaucolight for Schlemm's canal probing. The study of technical possibilities presented by the stent implantation was performed on two enucleated eyes with terminal glaucoma without previous surgery. NDPS was performed followed by probing and drainage implantation. RESULTS: During an attempt to implant the drainage as a whole ring we encountered difficulties that could be attributed to nitinol rigidity, residual septs inside Schlemm's canal, and the drainage insertion into collecting channel opening. In this case the ring was divided into two segments, which were implanted into the nasal and temporal side of the sinus venosus, starting from sclerectomy zone. In the experiment, there were no false passage formation, trabecular meshwork rupture and Descemet's membrane detachment. Macropreparations study revealed no damage through the trabecular meshwork and Descemet's membrane defects. In all cases, the whole implant was located in the Schlemm's canal lumen. Ultrasound biomicroscopy in both eyes revealed a correct placement of the implant throughout the channel. CONCLUSION: The experiment confirmed a possibility of NiTi drainage implantation into eyes with terminal glaucoma, with no previous surgical or conservative treatment. Stent implantation is possible after preliminary viscocanalostomy and Schlemm's canal probing. The findings may serve as a basis for further clinical trials to optimize glaucoma surgical treatment.

PURPOSE: To study the effect of local preoperative therapy with steroid and non-steroid anti-inflammatory drugs (NSAIDs) (on the level of the oxygen saturation in anterior segment tissues and prolonging the hypotensive effect of trabeculectomy. METHODS: 80 patients with primary open-angle glaucoma were randomized into 4 groups of 20 people according to the study drug: Nepafenac, Dexasone, their non-fixed combination and the control group with no preoperative therapy. All patients underwent trabeculectomy. The patients administered 1 drop of study drug b.i.d. for 2 weeks before the operation and were examined each day for the first week, on weeks 1, 2 and 4, and on months 3, 6 and 12. Oxygen saturation (SO2) was measured in supralimbal and sublimbal deep conjunctival veins before and after 2 weeks of anti-inflammatory therapy. Main outcome measure was the incidence of postoperative surgical or medical interventions (needling, needling revision, hypotensive therapy). RESULTS: In combined anti-inflammatory treatment group, SO2 increased by 5.2% (from 53.6 to 56.4%), in steroid treatment group - by 4.7% (from 52.7 to 55.2%), in nonsteroidal treatment group - by 2.6% (from 53.4 to 54.8%). In controls, no significant changes in SO2 were observed. 50% of patients in the control group needed postoperative needling, 35% in the NSAIDs, 30% - in the steroid drug group and 20% - in the combined therapy group. 10% of the control group and 5% of the NSAIDs required a needling-revision in the postoperative period. Patients from the steroid and combined therapy groups had no need of a needling procedure. 50% of patients in the control group, 35% in the NSAIDs group, 25% in the steroid drug group and 20% in the combined therapy group required further hypotensive therapy. Complete surgery success in the course of the first year amounted to 50% in patients in the control group, 65% in the NSAIDs group, 75% of the steroid drug group and 80% in the combined therapy group. Qualified success during the first year after surgery totaled 100% in all the groups. CONCLUSION: Pre-op topical anti-inflammatory treatment significantly increased venous oxygen saturation in anterior segment tissues which correlated with 1-year rate of absolute success of trabeculectomy as compared with controls. Local preoperative administration of anti-inflammatory drugs helped increase the complete surgery success throughout a year after trabeculectomy as compared to the control group. The best hypotensive effect was noted in the combined therapy group (80%), then - in the steroid and non-steroid monotherapy groups (75% and 65%).

Choroidal detachment (CD) is one of the most serious complications after deep sclerectomy (DS). Main pathophysiological mechanisms of CD include: hydro- and hemodynamics disorder, irido-lenticular diaphragm shift leading to a change in the intraocular camera volume, traction on the choroid, suprachoroidal space expansion leading to negative pressure formation, plasma extravasation into the suprachoroidal space, lysosomal enzymes and immunological status effect. CD late detection and lack of treatment may lead to serious complications. Scientific literature widely reported cases of CD after deep sclerectomy in patients with glaucoma. This paper presents two clinical cases of spontaneous bilateral ciliochoroidal detachment in non-operated eyes in patients with angle-closure glaucoma and after DS. Presented clinical cases demonstrate necessity to develop a clear treatment algorithm for patients with angle-closure glaucoma in the presence of comorbid medical conditions. Surgical method of choice for angle-closure glaucoma should be pathogenetic, microinvasive and less traumatic, such as cataract phacoemulsification, microinvasive non-penetrating deep sclerectomy with peripheral laser iridotomy.

Today, the method of spectral optical coherence tomography (SD-OCT) is gaining the main role in the early diagnosis of glaucoma. The thickness of the peripapillary retinal nerve fiber layer (RNFL) is the most reliable clinical parameter in this regard. However, recent literature data suggests an important role of the study of the macular inner layers, in particular the parameters of ganglion cell complex (GCC), focal loss volume (FLV) and global loss volume (GLV) for the early glaucoma detection. In this regard, the study of the ONH and lamina cribrosa is of less diagnostic value. At the same time researchers are focused on minimum width of the neural rim (minimum rim width, MRW), - a promising new option in early glaucoma diagnostics. The application of SD-OCT for determining glaucoma progression is still under development. The review provides a comparative analysis of these methods for early diagnosis and monitoring of the disease. Limitations of OCT in glaucoma diagnostics are noted. The advantages of combining structural and functional evaluation methods in glaucoma diagnostics are also shown.

Oxygen content in body fluids and tissues is an important indicator of life support functions. A number of ocular pathologies, e.g., glaucoma, are of presumable vascular origin which means altered blood supply and oxygen circulation. Most oxygen is transported in blood bound to hemoglobin. When the blood is passing through the capillaries, oxygen releases, i.e., oxygenated hemoglobin converts into deoxygenated hemoglobin. This process is accompanied by the changes in spectral characteristics of hemoglobin which result in different colors of arterial and venous blood. Photometric technique for the measurement of oxygen saturation in blood is based on the differences in light absorption. Blood oxygen saturation is measured by oximetry. In medicine, the most common method is pulse oximetry which assesses tissue oxygenation. In ophthalmology, this technique was applied to study blood saturation in glaucoma and to analyze the efficacy of glaucoma therapy. Oxygen concentration can also be evaluated by measuring oxygen partial pressure, i.e., pressure from the dissolved oxygen in blood. In ophthalmological practice, this parameter was measured in anterior chamber fluid in glaucoma after instillations of hypotensive eye drops as well as in vitreous body near to the optic disc under various levels of intraocular pressure. Currently, retinal oximetry allows for the calculation of oxygen saturation in retinal blood vessels. This technique is based on the assessment of light absorption with blood depending on hemoglobin saturation with oxygen by analyzing spectral composition of light reflected from the retina. Oximetry of bulbar conjunctival and episcleral microvasculature can be performed as well. This technique allows for the evaluation of oxygen saturation in vessels which collect blood from the anterior segment and the characterization of anterior segment metabolism in a number of ocular pathologies and in the course of treatment.

Age-related macular degeneration (AMD) and glaucoma are both chronic eye diseases and also a major cause of blindness and visual impairment among the elderly. Current epidemiological studies predict an increase in the prevalence of these diseases in the population due to aging. A thorough study of genetic and pathophysiological aspects of each of these diseases has led to the conclusion that there is some similarity of processes that underlie these pathologies. A lot of works devoted to the study of genetic aspects of each of the diseases, specific genetic polymorphisms that determine the degree of risk, clinical course and response to treatment are highlighted. Risk factors for AMD and glaucoma, the main of which are similar in both pathologies, are characterized. One of the key roles in pathogenesis of these diseases is assigned to the immune system: cytokine status of patients with AMD and glaucoma is described. The role of VEGF in the development of both diseases is identified, which gives additional opportunities to improve the basic approaches to treatment in the presence of comorbidity. The review provides integrated modern concepts of etiology, classification and pathogenesis of AMD and glaucoma, their intercommunication is described.