[Wavefront characteristics in amblyopia of different etiologies in children]. / Osobennosti volnovogo fronta pri ambliopii razlichnogo geneza u detei.

Purpose. The study investigates corneal and higher-order internal aberrations in patients with amblyopia of different etiologies and their relationship with visual acuity, refraction, axial length, and fixation parameters. MATERIAL AND METHODS: Forty-five patients (90 eyes) were examined. All patients were divided into five groups: 1 - with dysbinocular amblyopia; 2 - with refractive amblyopia; 3 - with anisometropic amblyopia; 4 - with relative amblyopia due to congenital myopia; 5 (control) - fellow eyes without amblyopia. Aberrometry was performed using the OPD-Scan III device (Nidek, Japan). Fixation parameters were studied on the MP-3 microperimeter (Nidek, Japan). Correlation analysis was performed using Pearson's linear correlation coefficient (r). RESULTS: In amblyopia associated with congenital myopia, a significant increase in corneal and internal aberrations RMS, Total HOA, astigmatism (V) (0.65±0.26; 1.01±0.31; 4.22±1.17; -2.17±0.72; 0.86±0.3, respectively; control group - 0.44±0.19; 0.58±0.27; 1.0±0.75; -0.94±0.89; 0.47±0.65) and internal spherical aberration (0.06±0.02; control group - 0.04±0.03) was found. In dysbinocular amblyopia, a significant increase in internal aberrations Trefoil (V) and Coma (H) (0.75±0.52 and 0.17±0.35, respectively; control group - 0.05±0.28 and -0.07±0.21) was found, which correlated with a decrease in fixation density in the 2° ring (r= -0.40, r= -0.41). CONCLUSIONS: The increased level of higher-order aberrations in amblyopia associated with congenital myopia is due to the anatomical and optical features of the eyes. The increase in internal aberrations Trefoil (V) and Coma (H) in dysbinocular amblyopia is associated with a mismatch of the optical elements of the eye due to impaired fixation, i.e., it is not the cause, but the consequence of amblyopia.

[Pathogenetic role of multifunctional protein alpha-2-macroglobulin and its activity in tears and serum in age-related macular degeneration and proliferative diabetic retinopathy]. / Patogeneticheskaya rol' polifunktsional'nogo belka α2-makroglobulina i ego aktivnost' v sleze i krovi pri vozrastnoi makulyarnoi degeneratsii i proliferativnoi diabeticheskoi retinopatii.

Alpha-2-macroglobulin (α2-MG) is a multifunctional protein involved in neurodegeneration, inflammation and neovascularization, which are key processes in the pathogenesis of age-related macular degeneration (AMD) and proliferative diabetic retinopathy (PDR). AMD and PDR are two of the main causes of vision loss and blindness, are difficult to treat, and are generally diagnosed at the stage of irreversible changes. PURPOSE: This study estimates the activity of α2-MG in the blood serum and tears of patients with AMD and PDR in order to reveal the relation of its levels with the intensity of the pathological process in the retina. MATERIAL AND METHODS: The study included 17 patients (34 eyes) with AMD, 15 patients (30 eyes) with PDR, and 15 healthy adults (30 eyes) of the similar age. The activity of α2-MG in serum and tears was measured enzymatically using the specific substrate N-benzoyl-DL-arginine-p-nitroanilide (BAPNA). RESULTS: The activity of α2-MG in tears of patients with AMD was on the average 3.5 times higher than in healthy controls, and in patients with PDR - 1.5 times higher. Patients with AMD at the submacular fibrosis stage showed decreased α2-MG activity in tears. The activity of α2-MG in serum of patients with AMD and PDR was on the average 25% higher than in healthy persons. No correlation was revealed between serum and tear levels of α2-MG activity. CONCLUSION: This study revealed for the first time that in AMD and PDR the activity of α2-MG in tears is increased, and that in AMD the increase is higher than in PDR. An increase of α2-MG activity in serum confirms the presence of systemic inflammation. Absence of correlation between the serum and tear activity of α2-MG confirms its local origin. The high level of α2-MG activity in tears reflects the presence of an active destructive process in the retina, justifying its further investigation as a predictor of AMD and PDR course, as well as an indicator of therapy effectiveness.

[Changes of a2-macroglobulin activity and endothelin-1 concentration in tears of rabbits after transplantation of retinal pigment epithelium cells derived from the induced pluripotent stem cells]. / Izmenenie urovnia a2-makroglobulina i éndotelina-1 v sleznoi zhidkosti krolikov posle transplantatsii kletok retinal'nogo pigmentnogo épiteliia, differentsirovannykh iz indutsirovannykh pliuripotentnykh stvolovykh kletok.

Retinal diseases accompanied with the dysfunction or death of the retinal pigment epithelial (RPE) cells are widespread, hard to treat, and appear to be a leading case of visual loss and blindness among the persons older than 55 years. Transplantation of RPE cells derived from the induced pluripotent stem cells (IPSC-RPE) is a promising method of therapy for these diseases. To ensure the transplant survival instant follow-up is required. It can be based on biochemical analyses of tear fluid that can be easily non-invasively collected. For the post-transplantation process monitoring we have choosen such polyfunctional bioregulators as α2-macroglobulin (α2-MG) and endothelin-1 (ET-1). RPE atrophy in New Zealand Albino rabbits was modeled via the subretinal injection of bevacizumab. IPSC-RPE in suspension or as a monolayer on the scaffold were transplanted subretinally 1 month after the injection. α2-MG activity and ET-1 concentration in tears were estimated during the first month and after 2, 3 and 7 months after transplantation. On the 7-14 days after transplantation α2-MG activity increased in tears of the both operated and controlateral eye probably as a reaction on the corticosteroid therapy. In 50% rabbits there was one more increase after 2-3 months that could be due to the immune inflammation. Concentration of ET-1 in tears decreased dramatically on the 7-14 days and 7 months after transplantation, and it could have an influence upon the retinal vassal tone. The data obtained show that estimation of bioregulators in tears can help monitoring local metabolic processes after RPE transplantation that is necessary for the opportune, reasonable and focused medicamental correction of post-transplantation process.

[Experimental stem cell replacement transplantation in retinal pigment epithelium atrophy]. / Zamestitel'naya transplantatsiya stvolovymi kletkami pri atrofii retinal'nogo pigmentnogo epiteliya v eksperimente.

PURPOSE: To develop and evaluate the results of the modified surgical technique for transplantation of retinal pigment epithelium (RPE) differentiated from human induced pluripotent stem cells (iPSC-RPE) in the form of a cell suspension into the subretinal space of rabbits with previously induced RPE atrophy. MATERIAL AND METHODS: The study was conducted on 10 New Zealand albino rabbits (20 eyes). One month after modeling RPE atrophy and retinal degeneration, rabbits were subjected to subretinal transplantation of iPSC-RPE cells in the form of a cell suspension. To prevent reflux of iPSC-RPE into the vitreal cavity, the injection site was sealed with 2-3 drops of autologous platelet-rich plasma (PRP). All rabbits underwent spectral optical coherence tomography (SOCT) and autofluorescence studies on the Heidelberg Spectralis system («Heidelberg Engineering¼, Germany). Enucleated animal eyes were studied with morphological and immunohistochemical methods. RESULTS: In this study we developed and evaluated a modified surgical technique of transplantation of iPSC-RPE in the form of a cell suspension into the subretinal space of rabbits with induced RPE atrophy. It was found that the use of PRP helps seal the defect and prevents cell suspension reflux into the vitreous cavity, effectively minimizing intra- and postoperative complications. Morphological in vivo study and examination of histological sections showed that implantable iPSC-RPEs were correctly integrated and adhered to the choroid in the surgery site. Immunohistochemical analysis involving fluorescence-marked antibodies confirmed the survival of iPSC-RPE integrated into the retina of model animals. CONCLUSION: This method improves the technology of iPSC-RPE transplantation on preclinical stages of the study, revealing new prospects in the treatment of degenerative diseases of the retina and the possibility of a personalized approach.

Features of Local Expression of Genes of Immune Response Cytokines and Trophic and Vasoregulatory Factors in Modeling of Retinal Pigment Epithelium Atrophy.

Local expression of genes encoding IL-1ß, IL-18, MCP-1/CCL2, PEDF, VEGF-A, and ZO-1 in the retina-retinal pigment epithelium-chorioidea tissue complex was studied in healthy rabbits and animals with simulated retinal pigment epithelium atrophy. Retinal pigment epithelium atrophy was modeled by single subretinal injection of 0.01 ml 0.9% NaCl (group 1; n=17) or 0.01 ml solution containing angiogenesis inhibitor bevacizumab in a dose of 0.025 mg (group 2; n=18). The gene expression was evaluated by reverse transcription PCR. In 27.7% cases, atrophic changes in the fundus were accompanied by a significant increase of IL-1ß gene expression and in more than 50% cases by an increase in VEGF-A and MCP-1/CCL2 mRNA levels. These factors contribute to an increase in the permeability of the blood-retina barrier and abolition of the immune privilege of the posterior eye segment, which should be taken into account when testing invasive approaches, in particular, for approbation of various options of replacement therapy with retinal pigment epithelium stem cells and development and use of neuroprotectors and drugs of targeted action.

[Optical aberrations of the eyes with various degrees of myopia]. / Aberratsii opticheskoi sistemy glaza pri miopii razlichnoi stepeni.

Purpose - to comparatively analyze the wavefront aberrations and biometric parameters of the eyes with various degrees of myopia. MATERIAL AND METHODS: The study included 134 eyes of 67 patients with mild, moderate and high myopia aged 7-28 (mean age 19.3±1.5 years). The following biometric parameters were examined: anterior chamber depth (ACD), lens thickness (LT), axial length (AL), as well as corneal and total aberrations. The parameters were studied on the Galilei G6 system (Ziemer Ophthalmic Systems AG, Switzerland) and the OPD-Scan III aberrometer (Nidek, Japan). Spherical aberration (SA) was estimated as the sum of Z4+Z8+Z12. RESULTS: As the refraction increased, the root mean square higher-order aberrations (RMS HOA) also increased significantly: from 0.24±0.02 µm in mild myopia to 0.45±0.03 µm in high myopia, and in eyes with AL of ≥27.0 mm - to 0.57±0.02 µm (p=0.01). An increase in vertical tilt, vertical coma and vertical trefoil were also observed. Total SA was positive and increased in eyes with moderate myopia compared to those with low myopia (from 0.02±0.01 µm to 0.06±0.02 µm, p=0.02), which coincided with changes in the internal optics of the eye: an increase in ACD and a decrease in LT. At the same time, no differences in corneal aberrations were observed among patients with low and moderate myopia. A significant decrease of SA occurred in high myopia (from 0.06 µm in low myopia to 0.015±0.02 µm in high myopia). The average value of SA was 0.005±0.01 µm in eyes with AL of ≥27.0 mm and appeared to be negative in 40% of cases. The average value of corneal SA was negative (-0.002±0.01µm) in eyes with AL of ≥27.0 mm. This group had predominantly patients with congenital myopia. CONCLUSION: An increase of total positive SA in patients with moderate myopia compared to those with low myopia is associated with changes in the internal optics of the eye (ACD, LT). Significant increase of higher-order aberrations and decrease of SA with the transition to negative values was observed in patients with high axial myopia.

[Bradykinin and angiotensin-converting enzyme in serum of patients with diabetic retinopathy and the prognosis of diabetic macular edema development (pilot study)].

BACKGROUND: Diabetic macular edema (DME) is a microvascular complication of diabetic retinopathy. One of the key roles in the pathogenesis of DME may belong to the components of rennin-angiotensin and kallikrein-kinin systems: bradykinin (Bk) and angiotensin-converting enzyme (ACE). PURPOSE: To determine the Bk and ACE concentration and ACE activity in serum of patients with proliferative diabetic retinopathy (PDR) and to estimate the significance of these parameters for the early diagnostic and prognosis of DMO. MATERIALS AND METHODS: Serum was collected from the 2 groups of patients with II type diabetes. Group I (n=9) had DME, group II (n=27) had PDR without DME. Control group (n=14) consisted of adult volonteers without diabetes and ophthalmic diseases. Concentration of Bk and ACE was measured using ELISA kits, ACE activity was determined enzymatically with specific fluorogenic substrate. RESULTS: Concentration of Bk in serum of patients without DME did not differ from one in controls (12,00 (9,70; 12,40) pg/ml) while all patients with DME had Bk level of 14,69 (13,68; 16,78) pg/ml that was significantly higher (p<0,01). In patients without DME ACE concentration (88,60 (77,30; 97,45) ng/ml) and ACE activity (6,8 (5,1;7,1) nmol/min·ml) were higher than normal (p<0,01) while in the case of DME concentration of ACE increased (77,36 (70,24; 86,29 ng/ml, p<0,01) and activity remained normal. The Bk/ACE concentrations ratio decreased in patients without DME and increased in those having DME. CONCLUSION: Patients with DME have increased Bk concentration along with nearly normal ACE concentration that indicate predominance of Bk synthesis over its degradation that may lead to the DME development. The Bk/ACE ratio decrease in patients with uncomplicated PDR and increase significantly in ones with DME. It means that determination of Bk in serum of patients with PDR may be used for the prediction of DME development. The Bk/ACE concentrations ratio may be even more informative.

[Electroretinographic signs of retinal remodeling after experimental induction of retinal pigment epithelium atrophy]. / Elektroretinograficheskie priznaki remodelirovaniya setchatki posle induktsii atrofii retinal'nogo pigmentnogo epiteliya v eksperimente.

Various animal models of atrophy of retinal pigment epithelium (RPE) are created in order to study certain aspects of geographical atrophy in humans. To study the effects of new methods of therapy, it is necessary to determine the objective functional markers of structural changes in the retina. PURPOSE: To determine the alterations in activity of the retina that characterize its remodeling in induction of RPE atrophy. MATERIAL AND METHODS: Full-field electroretinograms (ERG), pattern ERG, and multifocal ERG were recorded according to the ISCEV standards from the right eyes of twenty rabbits of the New Zealand albino breed 6-7 weeks after induction of RPE atrophy by subretinal administration of 0.9% sodium chloride or bevacizumab solution. RESULTS: Characteristic electroretinographic signs of RPE atrophy and retinal remodeling are described. Changes in ERG indicate a predominant inhibition of the functional activity of photoreceptors compared with bipolar cells, which objectively reflects an impairment of their metabolism associated with RPE pathology. With the injection of bevacizumab, a sharp weakening of the functional symbiosis of Mueller cells with bipolar cells was observed. According to pattern ERG, the function of the retinal ganglion cells was reduced. The reaction of the paired eyes after induction of RPE atrophy included a moderate decrease in the amplitude of b-wave of photopic ERG and activation of glia-neuronal relationships. CONCLUSION: Subretinal injections of 0.9% sodium chloride and bevacizumab trigger changes in the retina that reflect specific remodeling of retinal neurons of the second and third orders, which characterizes the used models of RPE atrophy.

[Experimental study of the effect of corneal hydration and its biomechanical properties on the results of photorefractive keratectomy]. / Vliyanie gidratatsii i biomekhanicheskikh svoistv rogovitsy na rezul'taty fotorefraktsionnoi keratektomii v eksperimente.

Water content in the cornea may affect the outcome of its excimer laser ablation, especially in presbyopic patients with myopic refraction. This hypothesis can be tested by scanning the cornea in the terahertz (THz) range to determine its hydration level. PURPOSE: To study the effect of hydration of the cornea determined by non-contact THz scanning and its biomechanical parameters on the results of photorefractive keratectomy (PRK) in an experiment. MATERIAL AND METHODS: PRK was performed using the Nidek EC-5000 QUEST excimer laser on 8 rabbit eyes. Corneal hydration was evaluated by determining the reflection coefficient (RC) in the THz electromagnetic radiation range before PRK, after 3-5 days, and after 1, 2, 3, and 4 months. Clinical examination included autorefractometry, assessment of corneal thickness and other anatomical and optical parameters of the anterior eye segment (Galilei G6, Ziemer Ophthalmic Systems AG 6.0.2, Switzerland), measurement of corneal hysteresis (CH) and corneal resistance factor (CRF) using the Ocular Response Analyzer (ORA; Reichert, USA), as well as tear production (Schirmer test). RESULTS: The initial water content in the cornea has a significant effect on the thickness of the removed layer, i.e. on the PRK effect, with correlation coefficient of Rs= -0.976 (p<0.01). The correlation between CH and the ablation depth is less pronounced (Rs=0.643), and CRF had no correlation with it (Rs= -0.089). Biomechanical indicators of the cornea depend on its hydration: changes in CH and CRF after excimer laser ablation qualitatively coincide with changes in RC, the correlation coefficient between RC and the initial value of CH is R= -0.619 (moderate negative correlation). CONCLUSION: THz scanning is an effective non-contact technology for monitoring corneal hydration level. The mismatch of the hypoeffect of keratorefractive excimer laser intervention planned for patients with presbyopia with the actual outcome can be caused by individual decrease in the initial water content in the cornea.

[Protocol of intravitreal drug delivery. Consensus of the Expert Counsil of Retina and Optic Nerve Diseases of the All-Russian Public Organasation «Association of Ophthalmologists¼]. / Protokol vypolneniya intravitreal'nogo vvedeniya lekarstvennykh preparatov. Konsensus Ekspertnogo soveta po zabolevaniyam setchatki i zritel'nogo nerva Obshcherossiiskoi obshchestvennoi organizatsii «Assotsiatsiya vrachei-oftal'mologov¼.

Intravitreal drug administration is a procedure that has become widespread in modern ophthalmology. However, there is no global consensus on certain aspects of this manipulation, and practitioners feel the need for guidelines. In the Russian Federation, until now, such a document was not available. The expert council on diseases of the retina and optic nerve of All-Russian public organization «Association of Ophthalmologists¼, with participation of invited specialists, has studied and analyzed the existing foreign guidelines for performing intravitreal injections, as well as the regulatory framework in Russia. As a result, this Protocol was developed and approved for use in the healthcare system of the Russian Federation. The document regulates the requirements for specialists and organizations, the conditions for performing the procedure and the necessary material resources and presents an algorithm for performing intravitreal drug administration, a patient examination check-list for various conditions of the procedure, as well as parameters for evaluating and monitoring the quality of the procedure.

[Bilateral occlusion of retinal vessels in Waldenstrom's disease (a case study)]. / Dvustoronniaia okkliuziia retinal'nykh sosudov pri bolezni Val'denstrema (klinicheskoe nabliudenie).

The article describes a clinical case of bilateral occlusion of retinal vessels in a patient with Waldenstrom's disease - a rare lymphoplasmocytic tumor of the bone marrow characterized by a complex of syndromes, among which the syndrome of blood hyperviscosity dominates. Comprehensive clinical, instrumental and laboratory examinations revealed that besides the syndrome of blood hyperviscosity the patient also had loci of cerebral ischemia (according to magnetic resonance imaging), ocular hypoperfusion with severe deficiency of retinal and choroidal blood flow (according to Doppler methods) indicating the presence of ocular ischemic syndrome. Since bilateral occlusion of retinal vessels without concomitant vascular and/or systemic pathology is rare, patients with such diagnosis should be referred to a hematologist.

[The effect of intravitreally administered angiogenesis inhibitor on the concentration of angiotensin-converting enzyme in the blood serum and lacrimal fluid in patients with diabetic macular edema].

BACKGROUND: Diabetic retinopathy (DR) is one of the more serious complications of diabetes and the main cause of blindness among working-age individuals. In recent years, information has emerged on the possible role of the renin-angiotensin system (RAS) in the pathogenesis of DR, and DR's possible connection with the system of pro-angiogenic factors. AIM: To study the impact of anti-angiogenic therapy on systemic and local concentrations of angiotensin-converting enzyme (ACE), a key component of RAS, for patients with diabetic macular edema (DME). MATERIAL AND METHODS: The concentration of ACE in the lacrimal fluid and blood serum in 10 patients (20 eyes) with DME was determined before and after intravitreal injection (IVI) of ranibizumab. The comparison group consisted of 7 patients (14 eyes) with age-related macular degeneration (AMD). The control group consisted of 10 healthy individuals (20 eyes). All groups were comparable in age and sex. The concentration of ACE was determined by enzyme immunoassay. The main group was examined four times: before IVI of ranibizumab, and then one week, two weeks and one month after IVI of ranibizumab. The comparison group was examined before, and then one week after, IVI of ranibizumab. RESULTS: In patients with DME, there was an initial 1.8-fold increase in the concentration of ACE in the lacrimal fluid of both eyes. A week after IVI of ranibizumab, the concentration of ACE in the lacrimal fluid began to decrease, reaching the control level after two weeks, and remaining there one month after IVI of ranibizumab. Initially, the concentration of ACE in the blood serum in patients with DME was 2.2 times lower than the control level. After IVI of ranibizumab there was an increase in the concentration of ACE in the blood serum, but by the end of the observation, the indicators continued to remain well below the control level. In patients with AMD, the initial concentration of ACE in the lacrimal fluids was not elevated; the concentration of ACE in the lacrimal fluids decreased 1.4 times one week after IVI of ranibizumab. The concentration of ACE in the blood serum of the patients with AMD was initially 25% lower than the control level, and essentially did not change after IVI of ranibizumab. СONCLUSIONS: Changes in the concentration of ACE in patients with DME may be a new prognostic criterion for the development of DME for patients with diabetes. These changes in the concentration of ACE, in the context of antiangiogenic therapy, indicate an interaction between the renin-angiotensin and angiogenic systems. Similar changes that were observed after IVI of ranibizumab in patients with AMD confirm the mutual influence of these two systems. The data presented in this study open up prospects for finding new pathways of pathogenic therapy for diabetic macular edema and diabetes.

[Possibilities of multicolor confocal scanning laser ophthalmoscopy in complex diagnostics of severe proliferative diabetic retinopathy]. / Lazernaia mul'tikolor-oftal'moskopiia v kompleksnoi diagnostike tiazheloi proliferativnoi diabeticheskoi retinopatii.

Multicolor scanning laser ophthalmoscopy (multicolor SLO) is a new informative method of eye fundus visualization. The method is based on synchronously obtaining three separate confocal images with monochromatic laser sources - blue (488 nm), green (515 nm) and infrared (820 nm), which are then combined into one in the Multicolor mode. PURPOSE: To evaluate the informative value of multicolor SLO in a complex examination of patients with severe proliferative diabetic retinopathy (PDR). MATERIAL AND METHODS: A total of 46 patients (62 eyes) aged 19 to 75 years with severe PDR was examined. All patients had massive growth of proliferative tissue on the eye fundus, which caused traction deformation and/or retinal detachment in the posterior pole. Optical mediums of the eyes were sufficiently transparent to obtain high quality images. All patients underwent color photo-registration of the fundus, fluorescein angiography (FA), optical coherence tomography (OCT) and multicolor SLO under drug-induced mydriasis. RESULTS: Pseudo-volumetric images obtained with multicolor SLO allow visualization of of preretinal proliferative membranes and their structure, the degree of their vascularization, the anatomical features of their attachment to retina, and the occluded vessels on fundus periphery. Being an additional option on scanning laser ophthalmoscope, the technique does not require special equipment, which enables several separate examinations, including OCT and FA, to be performed on a single device. CONCLUSION: Multicolor SLO is a promising new method of visualizing structures of the eye fundus and can be successfully used in complex diagnostics, monitoring and preoperative preparation of patients with severe PDR.

[Influence of treatment adherence on the progression of primary open-angle glaucoma in clinical setting]. / Vliianie priverzhennosti k lecheniiu na progressirovanie pervichnoi otkrytougol'noi glaukomy u patsientov v usloviiakh klinicheskoi praktiki.

According to various studies, treatment adherence of patients with primary open-angle glaucoma ranges from 5% to 80% and significantly influences the effectiveness of the therapy. Some authors report higher levels of adherence in patients receiving preservative-free medications. PURPOSE: To study the influence of treatment adherence in patients receiving preservative-free and preserved medications on the progression of primary open-angle glaucoma (POAG). MATERIAL AND METHODS: This prospective multicenter non-interventional study was conducted in clinical setting and included 504 patients with primary open-angle glaucoma receiving drug therapy; 51 ophthalmologist was involved in the management of patients' diaries. RESULTS: The percentage of patients who did not reach target IOP was three times lower in the group with high adherence, in comparison to patients with medium and low adherence (7% against 22%, respectively). Development of side effects was one of the factors influencing treatment adherence, their rates and expressiveness were much lower in the preservative-free group compared with the group receiving preserved medication (13.9% against 35.4%). The rate of patients who did not reach target IOP was two times lower in the group of preservative-free medication (10% against 21%). CONCLUSION: The study confirms that preservative-free glaucoma medication promotes higher adherence to treatment in clinical setting predominantly due to the reduction of quantity and severity of side effects leading to treatment gaps, which results in increased effectiveness and better stabilization of glaucoma.

[Wavefront and accommodation parameters under different conditions of correction in myopia and hyperopia]. / V.V., Parametry volnovogo fronta i akkomodatsii v raznykh usloviiakh korrektsii pri miopii i gipermetropii.

PURPOSE: To compare the wavefront and accommodation parameters without correction and in soft contact lenses (SCL) in natural and cycloplegic conditions in eyes with myopia and hyperopia. MATERIAL AND METHODS: A total of 142 myopic (mean -5.6±1.4 D) and 48 hyperopic (mean +3.5±1.1 D) eyes were examined in 95 patients aged 5-32 years (mean age 16.9±0.9 years) to compare the wavefront aberrations without correction and with different SCL before and after cycloplegia (two drops of cyclopentolate hydrochloride 1%). The device was set up for 4 mm zone for both narrow and wide pupils. To compare the accommodation parameters under different correction conditions, 85 patients aged 8-23 years (mean age 14.9±0.6 years) with average myopia of (-)5.27±1.4D (123 eyes) and average hyperopia of +3.53±1.2 D (46 eyes) were chosen from the study group. Among the measured parameters are objective accommodative response (OAR), relative accommodation reserves (RAR), pseudoaccumulation amplitude (PA), higher-order aberrations: RMSHOAs, 6-9 Trefoil, 7-8 Coma, spherical aberration (SA). RESULTS: In myopic eyes with SCL Coma 7 decreases, Coma 8 increases with transition to positive values, and Trefoil 9 increases. In hyperopic eyes, trefoil 6 decreases, Coma 7-8 go negative. In myopic or hyperopic eyes with SCL, SA goes from positive to negative. In both myopia and hyperopia, accommodation and PA rates are higher in SCL than in glasses. CONCLUSION: SCL change certain wavefront parameters for myopia and hyperopia in different ways. The accommodation parameters in SCL are elevated in both myopia and hyperopia. The negative spherical aberration induced by contact lenses improves the accommodative response. The revealed features should be considered in the development of correction methods that target refractogenesis.

[Impact of antiangiogenic therapy on ocular blood flow and microcirculation in diabetic macular edema]. / Vliianie antiangiogennoi terapii na glaznoi krovotok i mikrotsirkuliatsiiu pri diabeticheskom makuliarnom oteke.

Today, diabetic macular edema (DME) is still one of the main causes of vision loss in patients with diabetes. PURPOSE: To identify changes in the ocular blood flow and microvascular network of the macular zone in patients with DME after antiangiogenic therapy. MATERIAL AND METHODS: In the course of the study, 25 patients (50 eyes) with monolateral clinically significant DME aged 67.5±3.85 years were examined. Control group consisted of 75 healthy subjects (150 eyes). All patients underwent ultrasound examination of the eyes and orbits (in Color Doppler Imaging (CDI) and Pulse-Doppler modes) and OCT-angiography (OCT-A) before the intravitreal injection of ranibizumab, as well as 3 days, 2 weeks, and 1 month after the treatment. RESULTS: According to OCT-A, the initial values of microvascular network parameters were significantly below the norm (p<0.05). After intravitreal ranibizumab injection (IRI), no significant changes in the density of microcapillaries or in the parameters of foveal avascular zone (FAZ) were recorded. However, a transient increase of the FAZ area was revealed 2 weeks after the injection, as well as an increase of microcapillaries density in the central quadrant together with a decrease of density in the peripheral quadrants 1 month after IRI. By the end of the follow-up period, a decrease in the initially raised maximum systolic velocity (Vsyst) and resistance index (RI) in the ophthalmic artery (OA) of the affected eye were documented. Additionally, an increase in Vsyst and 2-fold increase in end-diastolic velocity (Vdiast), as well as a decrease in RI in the central retinal artery (CRA) on the affected and paired eyes were detected. CONCLUSION: The study revealed no negative effects of the angiogenesis inhibitor ranibizumab on retinal microcirculation or ocular blood flow. The registered changes in blood flow may indicate improvement of hemodynamic parameters after resorption of macular edema.

[Role of optical coherence tomography angiography in diagnostics of early choroidal melanoma and circumscribed choroidal hemangioma]. / Opticheskaia kogerentnaia tomografiia-angiografiia v diagnostike nachal'noi melanomy i otgranichennoi gemangiomy khorioidei.

Small choroidal melanoma is a malignant tumor that is prone to early metastasis, its amelanotic form is often similar to circumscribed choroidal hemangioma. The main attribute for tumor identification is its vascularization, which is the target of various examination methods. Optical coherence tomography angiography (OCTA) has not been previously used in complex diagnostics of early choroidal melanoma and circumscribed choroidal hemangioma for detection of tumor vessels and the nature of their branching, as well as for vessel caliber comparison. Purpose to examine vascularization of early uveal melanoma and circumscribed choroidal hemangioma by optical coherence tomography angiography. MATERIAL AND METHODS: The study included 23 patients with early choroidal melanoma (13 subjects) and circumscribed choroidal hemangioma (10 subjects) that were examined by optical coherence tomography angiography. According to ultrasound investigation, mean tumor prominence was 1.1±0.3 mm, mean base diameter - 8.1±0.6 mm. RESULTS: Optical coherence tomography angiography in 13 patients with small choroidal melanoma revealed presence of a neovascular component localized under retinal pigment epithelium (RPE) that had marginal avascular zone corresponding to the tumor slope. The loop-like shape of tumor vessels with numerous twists and interweaving was noted under retinal vessels. A tree-shaped neovascular component with large-caliber vessels in the form of a tree trunk with multiple branches extending from it was seen under RPE in 4 cases with circumscribed choroidal hemangioma; diffuse vascularization in the form of numerous tiny tortuous vascular branches was seen in 6 patients. CONCLUSION: Optical coherence tomography angiography allows detection of tumor`s own vessels with characteristics of their vascularization in early choroidal melanoma and circumscribed choroidal hemangioma. Increasing the frequency of detection of tumor`s own vessels will make possible early differential diagnostics of a malignant or benign tumor and will help establish adequate conserving therapy.

[Wavefront aberrations and accommodation in myopes and hyperopes]. / Aberratsii volnovogo fronta i akkomodatsiia pri miopii i gipermetropii.

AIM: to comparatively investigate accommodation, pseudoaccommodation, and higher-order aberrations in children and young adults with myopia and hyperopia. MATERIAL AND METHODS: A total of 39 myopic (the mean error of (-)5.2±1.5 diopters) and 53 hyperopic (the mean error of (+)3.1±1.15 diopters) eyes of 46 patients aged 5-20 years (11.6±0.6 years on average) were enrolled. Examination included evaluation of the objective accommodative response, relative accommodation reserves, pseudoaccommodation volume (calculated as the difference between the (+)3.0-diopter lens that is necessary for cycloplegic reading at a 33-cm distance and the weakest possible plus lens that enables reading), and higher-order aberrations (HOA), particularly the root mean square (RMS) value, vertical and horizontal trefoil, vertical and horizontal coma (coma7, coma8), and spherical aberration (SA). RESULTS: Both objective and subjective parameters of accommodation were reliably lower in myopia as compared to hyperopia, while wavefront aberrations (RMS HOA, vertical trefoil, coma7) and pseudoaccommodation - reliably greater. SA was found to be reliably more pronounced in those myopes, who demonstrated larger volume of pseudoaccommodation. At the same time, there was a mismatch in wavefront parameters of myopes and hyperopes at different levels of accommodation and pseudoaccommodation. In myopic eyes, vertical trefoil decreased down to negative values as the accommodative response improved. In contrast to that, in hyperopic eyes with large volume of pseudoaccommodation, SA decreased below zero. CONCLUSION: Myopia has been shown to be associated with reduced accommodation parameters as well as stronger HOA and pseudoaccommodation. Wavefront and accommodation parameters interrelations differ in myopic and hyperopic eyes. The nuances revealed should be taken into account when developing correction methods that purposefully influence refractogenesis.

[Assessing resveratrol effect on ocular blood flow in experiment].

AIM: To study the effect of resveratrol on ocular blood flow in vivo in healthy rats and those that underwent retinal ischemia/reperfusion. MATERIAL AND METHODS: The experimental study was performed on 40 Wistar rats (40 eyes). For ocular blood flow evaluation, color Doppler imaging (CDI), power Doppler (PD), and pulsed-wave spectral Doppler ultrasonography were performed using the Voluson E8 Expert ultrasonic diagnostic system (GE Healthcare). All rats were given resveratrol per os for 2 months of the study. Retinal ischemia/reperfusion injury was induced by a subconjunctival injection of endothelin-1. The control group included 10 intact animals. RESULTS: Signs of ischemic damage of the anterior and posterior eye segments were less pronounced in rats that were given resveratrol during both pre-ischemic (30 days) and post-ischemic (30 days) periods of follow-up. There was also a statistically significant increase in the peak systolic and end diastolic velocity of blood flow as well as a decrease in the resistive index of retrobulbar arteries in those rats that underwent ischemia/reperfusion as compared to the controls. CONCLUSION: Long-term resveratrol use (2 months) has proved effective in improving ocular blood flow in a rat model of retinal ischemia/reperfusion injury.

[Effects of dexamethasone and superoxide dismutase instillations on clinical course of uveitis and local biochemical processes (experimental study)].

AIM: to evaluate and compare the effect of topical superoxide dismutase (SOD), which is an antioxidant enzyme, dexamethasone, and a combination of these on the course of experimental uveitis in rabbits as well as biochemical parameters of aqueous and vitreous humor. MATERIAL AND METHODS: Acute uveitis was induced in 16 rabbits by a double injection (subcutaneous and intravitreal) of normal horse serum. Of them 12 animals, divided into 3 groups of 4 each, received topical SOD, dexamethasone, or both daily for 7 days. The remaining 4 rabbits (8 eyes) were treated with placebo and, thus, constituted the control group. On day 8 the following parameters were measured in aqueous humor: protein concentration, antioxidant activity, SOD activity, α2-macroglobulin level, and leukocyte number. Total protein and albumin levels in vitreous humor were also determined. RESULTS: The effects of SOD and dexamethasone instillations were considered similar in many parameters. However, SOD was associated with a greater increase in antioxidant activity and a greater decrease in aqueous humor leukocytes, while dexamethasone was more effective in decreasing aqueous humor α2-macroglobulin and vitreous humor protein and albumin. The substances had a synergistic effect on iridal edema as well as aqueous humor leukocyte number and α2-macroglobulin level. CONCLUSION. Adding SOD to the complex therapy of uveitis results in lower inflammation intensity and enhanced dexamethasone effect.