[Multimodal topographically oriented approach to the study of full-thickness macular holes]. / Mul'timodal'nyi topograficheski orientirovannyi podkhod k izucheniyu skvoznykh makulyarnykh razryvov.

PURPOSE: This article studies the relationship between structural changes according to the findings of optical coherence tomography (OCT) and OCT angiography (OCTA), microperimetry (MP), multifocal electroretinography (mfERG) parameters in topographically corresponding areas of the macular region in idiopathic full-thickness macular holes (FTMH). MATERIAL AND METHODS: OCT, OCTA, MP and mfERG were performed in 14 eyes with FTMH stages I-IV according to Gass. In 13 points at a distance of 0-2.5°, 2.5-5.0°, and 5.0-10.0° from the fixation point, the light sensitivity (LS), amplitude and latency of the P1 component were compared with the size of the hole, the area of cystic changes (CC) at the level of the inner nuclear layer (INL) and the outer plexiform layer and Henle fiber layer complex (OPL+HFL), vessel density in the superficial and deep capillary plexus (SCP and DCP). RESULTS: LS and P1 component amplitude were significantly reduced at a distance of up to 5.0° from the fixation point. LS correlates with the apical and basal diameter of the hole (R> -0.53), the area of CC in the INL (R> -0.62) and the OPL+HFL complex (R> -0.55), the density of vessels in the SCP at a distance of up to 2.5° from the fixation point (R>0.51) and in the DCP at a distance of up to 5° from the fixation point (R>0.49). The P1 amplitude correlates with the basal diameter of the hole (R= -0.38), the area of CC in the INL and the OPL+HFL complex (R> -0.33) and vessel density in the SCP (R=0.37) at a distance of up to 2.5° from the fixation point, as well as vessel density in the DCP at a distance of up to 5° from the fixation point (R=0.47). Vessel density in the DCP is significantly lower in the presence of CC in the retina (p<0.001). CONCLUSION: In FTMH, there is a relationship between bioelectrical activity and LS, and structural disorders, capillary perfusion in different layers of the retina. A multimodal topographically oriented approach allows studying the relationship between structural and functional parameters in individual points of the retina and can be used in monitoring of FTMH after surgical treatment.

[Factors affecting the hypotensive effect of selective laser trabeculoplasty in primary open-angle glaucoma]. / Faktory, vliyayushchie na gipotenzivnyi effekt selektivnoi lazernoi trabekuloplastiki pri pervichnoi otkrytougol'noi glaukome.

PURPOSE: This study analyzes the influence of various factors on the hypotensive effect of selective laser trabeculoplasty (SLT) in patients with primary open-angle glaucoma (POAG). MATERIAL AND METHODS: A retrospective study of the SLT effect was performed in 582 patients (756 eyes; mean age - 71.9±9.5 years) with POAG stages I-III. The level of intraocular pressure (IOP) decrease was assessed at 1 day, 1, 3, 6, and 12 months after SLT. The relationship between the hypotensive effect and age, gender, glaucoma stage, initial IOP level, number and type of instilled drugs, presence of intraocular lenses, and the surgeon performing the intervention were analyzed. RESULTS: In the entire sample, the hypotensive effect of SLT after 1 day was 4.1±3.4 mm Hg, after 1, 3, 6, and 12 months - 3.7±4.8; 3.5±3.8; 3.1±3.4 and 2.3±3.8 mm Hg, respectively. The hypotensive effect of SLT was most dependent on the preoperative IOP level (R>0.64, p<0.05). No significant correlation was found between the hypotensive effect and the stage of POAG, gender, age, number of hypotensive drugs, phakia/aphakia, and the surgeon. A weaker hypotensive effect of SLT was found in eyes receiving monotherapy with α2-adrenoceptor agonists (p<0.03) and a combination of four drugs (p<0.02). CONCLUSION: SLT is an effective method of additional IOP reduction in POAG at any stage and with any hypotensive regimen. At the same time, the results of its use in real clinical practice indicate the need for more careful IOP control after the procedure, especially in eyes with POAG stage III, as well as in eyes without hypotensive therapy and on the maximum drop regimen.

[Direct assessment of changes in biomechanical properties of the cornea after ReLEx SMILE and FemtoLASIK surgeries]. / Neposredstvennaya otsenka izmenenii biomekhanicheskikh svoistv rogovitsy posle provedeniya operatsii ReLEx SMILE i FemtoLASIK.

The aim of this study was to evaluate corneal biomechanical properties in myopic patients after ReLEx SMILE and FemtoLASIK surgeries using the Corvis ST analyzer. MATERIAL AND METHODS: The SMILE group comprised 23 patients (46 eyes) with spherical refraction -3.8±1.8 diopters (D), the FemtoLASIK group included 18 patients (36 eyes) with spherical refraction -3.5±1.3 D. Analysis of the biomechanical properties of the cornea was carried out using the CORVIS ST device (Oculus, Germany) before and seven days after corneal refractive surgery. RESULTS: In the SMILE group, with intraoperative decrease in corneal thickness of 91.43±19.43 µm, a significant increase in the following parameters was observed: deformation coefficient (DA ratio; p=0.0001), peak distance (PD; p=0.02) and inverse concave radius (ICR; p=0.003); a decrease in the stiffness parameter at first applanation (SP-A1; p=0.0001), Corvis biomechanical index (CBI; p=0.0001), intraocular pressure (IOP; p=0.001). In the FemtoLASIK group, with intraoperative decrease in corneal thickness of 75.33±32.3 µm, we observed a significant increase in DA ratio (p=0.0002), PD (p=0.04), ICR (p=0.0002), a decrease in SP-A1 (p<0.0001), IOP values (p=0.0003). In comparison with the FemtoLASIK group, the deformation amplitude DA changed significantly less in the SMILE group (p=0.04). In the FemtoLASIK group, in comparison with the SMILE group, the DA ratio (p=0.0009) and SP-A1 (p=0.0003) significantly increased. Intraoperative corneal thickness change correlates with ICR both in SMILE (R=0.52) and in FemtoLASIK (R=0.65). CONCLUSION: Corneal biomechanical properties determined with CORVIS ST in eyes with mild to moderate myopia change to a lesser extent after ReLEx SMILE compared to FemtoLASIK.

[Vortex vein varix (clinical observations)]. / Varikoznoe rasshirenie vortikoznykh ven (klinicheskie nablyudeniya).

Varix of the vortex vein ampulla is a rare benign condition that has clinical similarities to more concerning choroidal lesions that pose a threat to vision, in particular choroidal melanoma. The article describes two clinical cases, one of which is unique due to the combination of bilateral lesion and the presence of multiple varices in one eye. A brief review of the literature on this condition is also provided.

[Retinoprotective effects of Retinalamin studied in an experimental model of photochemical damage to rabbit retinas]. / Issledovanie retinoprotektornykh effektov retinalamina v eksperimental'noi modeli fotokhimicheskogo povrezhdeniya setchatki krolika.

Purpose - to investigate functional and morphological effects of peptide bioregulator (Retinalamin) in modeling of photochemical damage to rabbit retina. MATERIAL AND METHODS: The study was conducted on 36 rabbits (72 eyes) randomized into 4 equal groups: two experimental groups received parabulbar injections of Retinalamin («Geropharm¼, Russia) in each eye in dosages of 0.25 mg/kg in a course of 10 days starting from day 1 and day 10 of the experiment, respectively, and two control groups that received injections of normal solution with the same regimen. To simulate photochemical damage to the retina, exposure to light with a wavelength of 405 nm, a power density of 5 mW/cm2 and daily exposure time of 4 h was performed for 20 days. Multifocal and flicker 30 Hz electroretinogram (mfERG and fERG) were recorded, and histological studies of retina samples with quantitative assessment of retinal cells apoptosis by the TUNEL method were conducted before, as well as 10, 20 and 30 days after the start of light exposure. RESULTS: Ophthalmoscopic signs of light-induced retinal degeneration were revealed 6-10 days after start of exposure in all groups. When registering mfERG and fERG in all groups, there was a significant decrease in the amplitude of N1 and P1 peaks, retinal density of the bioelectric response of the P1 component, as well as the amplitude of fERG on days 10 and 20 after the beginning of light exposure (p<0.001 in comparison with the background values), and a slight increase in the indicators on day 30. Histological examination revealed a significant decrease in the number of cells in the outer nuclear layer and an increase in the proportion of apoptotic cells in the outer and inner nuclear layers on days 10 and 20 of the experiment, with a decrease on day 30 (after cessation of light exposure). Comparison of the groups receiving Retinalamin injections from days 1 or 10 of light exposure between themselves and the control groups revealed no significant differences in any of the studied parameters (p>0.05). CONCLUSION: No significant functional and morphological evidence of neuroprotective effects of Retinalamin were found in the model of photochemical damage to rabbit retinas.

Modeling of Retinal Degeneration.

We developed a model of retinal degeneration in rabbits based on exposure to light with a wavelength of 405 nm. This model allows reproducing structural and functional disorders in the central parts of the retina, including primarily degeneration of the outer layers of the retina (retinal pigment epithelium and layer of photoreceptor cells), and is designed to study the mechanisms of formation, progression and effectiveness of new drugs and methods of treatment of degenerative diseases of the retina.

[Multifocal electroretinography in the study of focal and diffuse damage to the rabbit retina]. / Mul'tifokal'naya elektroretinografiya v issledovanii ochagovykh i diffuznykh izmenenii setchatki krolika.

PURPOSE: To evaluate the possibility of using the system "Neuro-ERG" (with a module for multifocal ERG) in the study of focal and diffuse pathology in laboratory animals (rabbits). MATERIAL AND METHODS: Focal retinal damage was modelled in 5 eyes of 5 rabbits by singular laser pulses (532 nm, 100 ms, power 30, 60, 100, 150 and 200 mW) and diffuse retinal damage was modelled in 5 eyes of 5 rabbits by exposure to polychromatic light for 14 days (9500 lm, 6400 K, 230 mW/cm2, 8 h/day). The pair of eyes and areas of intact retina in the eyes with focal retinal damage were used for control. Multifocal electroretinography (mfERG) was recorded using the «Neuro-ERG¼ system (Neurosoft, Russia) before exposure, after 1 hour (in focal damage model), and 1, 7 and 14 days after exposure. In addition, three-time recording of mfERG was made before and after the experiments. Analysis included the amplitude and time characteristics of mfERG components, as well as the level of reproducibility of mfERG at each recording. RESULTS: In the modeling of focal damage of the rabbit retina, significant changes in mfERG (pattern stimulus consisted of 61 hexagons) were detected when the retinal damage area was more than 170 µm in diameter or more than 35% of the hexagon area in the pattern-stimulus. A significant moderate inverse correlation (0.52

[Acute ocular lesions after exposure to electromagnetic radiation of ultrahigh frequency (an experimental study)]. / Ostroe porazhenie organa zreniia élektromagnitnym izlucheniem sverkhvysokochastotnogo diapazona (éksperimental'noe issledovanie).

PURPOSE: To investigate the clinical and morphological manifestations of ocular lesions resulting from acute exposure to microwave radiation (MR). MATERIAL AND METHODS: Twenty-four rabbits were included in the study and divided into four equal groups according to MR exposure time (15, 30, 45, 60 s). The right eyes of rabbits were exposed to MR of 3.97 GHz and energy density of 1.0 W/cm2. The sham control group consisted of six animals. The exposed (right) and the paired (left) eye were studied for clinical and morphological changes, content of proinflammatory cytokines IL-1ß, IL-6 and TNF-α in the anterior chamber and in the vitreous body after exposure to MR. RESULTS: Significant dose-dependent changes in the structure of the exposed eye were revealed. Formation of microwave cataract was noted at the MR exposure time of 15 seconds and more. Partial or complete de-epithelialization, stromal edema, endothelial damage and inflammatory infiltration in the cornea, effusion of protein and cellular reaction in the aqueous humor were detected after MR exposure of 30, 45 and 60 seconds. Cellular reaction in the vitreous body was observed after exposure time of 45 and 60 seconds. Exposure to MR for up to 1 minute did not lead to visible clinical or morphological (traditional methods of examination) damage of the retina and optic nerve within 24 hours. Significantly higher content of proinflammatory cytokines IL-1ß, IL-6 and TNF-α in the aqueous humor and vitreous body was revealed in animals exposed to MR for 45 and 60 seconds. CONCLUSION: Acute exposure of the organ of vision to electromagnetic microwave radiation can lead to adverse dose-dependent effects not only in the lens, but also in other structures of the eye.

The Effect of Electromagnetic Fields of Extremely Low Frequency 30 Hz on Rat Ovaries.

We studied the effects of extremely low-frequency electromagnetic field on the ovaries in rats. The female rats were exposed to a 30 Hz sinusoidal magnetic field of 4 kA/m for 2 h per day for a period of 10 weeks, including the period of embryonic development. After the exposure, the duration of the estrous cycle and serum levels of luteinizing hormone, follicle stimulating hormone, progesterone, and estradiol E2 were measured in different phases of the estrous cycle and morphological changes in the ovaries were evaluated. Lower levels of follicle stimulating hormone in the proestrus and progesterone in the estrus phase were found; in the ovaries, the content of primordial follicles was lower than in the control. The exposure to electromagnetic field in the selected mode caused no significant defects in the structure and function of rat ovaries.

[Hyalocytes of the vitreous body and their role in ophthalmic pathology]. / Gialotsity steklovidnogo tela i ikh znachenie v glaznoi patologii.

Hyalocytes of the vitreous body are variety of tissue macrophages that exercise various functions - from ensuring the synthesis of extracellular matrix components and modulating the immune response in the vitreous body to participating in different stages of inflammatory processes. Some aspects of the biology of hyalocytes remain poorly understood and controversial. However, the vitreous cells are starting to be considered a potential point of application in the treatment of diseases of the vitreous body and the retina.

[Role of Chlamydia trachomatis intraocular infection in the development of proliferative vitreoretinopathy (experimental study)].

OBJECTIVE: To study the influence of C. trachomatis infection on proliferative vitreoretinopathy (PVR) stimulation and development in an experimental model. MATERIAL AND METHODS: Intravitreal C. trachomatis injection was performed in 17 rabbits (right eyes) out of which 8 developed minimal chlamydial damage (1 was further subjected to histopathological examination with pathogen detection in ocular structures and other 7 were included in the study group). The control group consisted of 7 rabbits with no laboratory evidence of chlamydial infection. PVR was induced by 4 peripheral retinal punctures with a 19 G needle. Follow-up methods included ophthalmoscopy, ultrasonography, and PVR grading according to the Fastenberg classification. Histopathological examination, supplemented with pathogen detection by direct immunofluorescence in the study group, was performed at weeks 7 and 20. RESULTS: PVR rate and severity were higher in the study group as compared with the controls (5 out of 7 rabbits, grade 2-4 vs. 2 out of 7 rabbits, grade 0-1, p<0.01). In the study group, histopathological examination performed before and after the induction of PVR revealed a pronounced lymphocyte and macrophage infiltration, characteristic of infectious inflammation. Similarly, extra- and intracellular chlamydial inclusions could be found in the retina and/or zones of proliferation throughout the whole study period. Inflammation signs (including those of proliferation) were reliably less significant in the controls. CONCLUSION: C. trachomatis infection of the posterior segment contributes to PVR development due to associated chronic inflammation.

[Lattice degeneration of the retina].

Lattice degeneration of the retina is a clinically important type of peripheral retinal dystrophies due to its participation in the pathogenesis of rhegmatogenous retinal detachment. In spite of extensive epidemiological, morphological, and clinical data, the question on causes of this particular type of retinal dystrophies currently remains debatable. Existing hypotheses on pathogenesis of retinal structural changes in lattice degeneration explain it to a certain extent. In clinical ophthalmology it is necessary to pay close attention to this kind of degenerations and distinguish between cases requiring preventive treatment and those requiring monitoring.

[Role of Chlamydia trachomatis and Chlamydophila pneumoniae in damage of eye posterior segment structures].

AIM: Study the ability of Chlamydia trachomatis and Chlamydophila pneumoniae to damage structures of eye posterior segment, features of development of such infectious process, its morphological and clinical characteristics. MATERIALS AND METHODS: 6 rabbits with confirmed absence of C. trachomatis, C. pneumoniae were used in the study. 3 animals were infected with C. trachomatis culture and 3 animals--with C. pneumoniae culture. Subconjunctival and intravitreal mode of infectious agent introduction were used, as well as instillation of its culture into conjunctival sac. Microbiological diagnostics included microscopy with direct immunofluorescence, culture method and determination of antibody titers. Infectious process was studied by using ophthalmologic methods and histological examination. Observation period was 4 months. RESULTS: In all the animals a development of infectious process at early stages after the infection was confirmed. Conjunctivitis symptoms, inflammatory exudation into vitreous humor, chorioretinal inflammation loci, disorders in transparency of optical media and detachment of retina were clinical manifestations. In 2 animals infected with C. trachomatis severe panuveitis was noted. In 4 animals infectious process assumed subclinical characteristics (infection with both C. trachomatis or C. pneumoniae). In pathomorphologic studies data on the ability of C. trachomatis and C. pneumoniae to cause damage to cells of retina, pigment epithelium and choroid were obtained. CONCLUSION: C. trachomatis and C. pneumoniae may play a significant role in pathology of vitreous humor, retina, pigment epithelium and choroid.

[Dystrophic changes of vitreous in ocular chlamydia infection].

Incidence and character of vitreous changes in ocular chlamydia infection was studied. 312 patients were enrolled into the study (175 males and 137 females) aged from 24 to 52 years old (mean age 38.4 +/- 5.2 years). 165 patients (330 eyes) with laboratory confirmed chlamydia conjunctival infection were included in the experimental group. 147 patients (294 eyes) without chlamydia conjunctival infection were enrolled to the comparison group. Each group was subdivided with regard to the age. Dystrophic changes of vitreous and its posterior detachment are more frequently revealed in eyes with Chlamydia trachomatis infection, besides it happens in a younger age.

[About development of chlamydia multiple organ lesions after primary ocular infection in experiment].

Chlamidia spp. are obligate intracellular pathogens that cause a variety of diseases in humans and animals. Their generalization was proved as hematogenic spreading from the urogenital (C. trachomatis) and the respiratory (C. pneumoniae) systems. The goal was to investigate the possibility of C. trachomatis infection spreading from the primary ocular gate. 6 animals were infected by instillation in the conjunctival sack, subconjunctival and intravitreal injections of C. thachomatis culture. C. trachomatis was detected by direct immunofluorescence method in the retina, retinal pigment epithelium, choroid, brain, the pancreas, the prostate gland and the urethra after primary ocular infection. The results of our study have proved the opportunity of C. trachomatis to cause polyorganic contamination.

[Retinal lesion in experimental chlamydia eye infection].

Until the present time, ophthalmic chlamydiasis has been generally associated with diseases of auxiliary organs of the eye and its anterior segment: conjunctivitis and iridocyclitis. The morphological substrate of eye posterior segment lesion caused by C. trachomatis and C. pneumonia was studied in this investigation. The pathomorphological pattern characteristic of chlamydia-induced rabbit retinal and vitreous body lesions is composed of vitreoretinal lymphocyte-macrophageal infiltrations of varying intensity, posterior hyaloid membrane detachment, peripheral foci or folding of the retina, impaired nuclei of photoreceptors and bipolar neurons, pigment epithelial damage occurring in different concurrences in relation to the species of a causative agent and the clinical picture.

[The clinical and morphological features of Chlamydia pneumoniae-induced chorioretinitis in an experiment].

The clinical and pathomorphological features of vitreous retinochorioidal complex lesion with the pathogen Chlamydia pneumoniae were studied. Three rabbits (6 eyes) were infected with Ch. pneumoniae strain TWAR by instillation, subconjunctivally and 2 eyes were infected by intravitreally. Contamination was controlled by direct immunofluorescence and cultivation (conjunctival scrapes, venous blood). A postmortem study was conducted 128 days later, by employing an immunohistochemical analysis. On days 7-14, all cases showed the signs of a uveal reaction; 4 cases developed chorioretinitis. In 2 cases, the process ran as endophthalmitis with minimal clinical manifestations. The rate of the process was decreased by days 40-50. On the postmortem study, all the cases displayed lymphocytic-macrophageal infiltration in the vitreous body and retina in the presence of retinal focal dystrophic changes. An immunohistochemical study revealed the pathogen in different retinal layers (both inside and outside the chorioretinal foci) in all 6 cases and in the preretinal layers of the vitreous body in 5 cases. The pathogen Ch. pneumoniae is rather highly tropic to the structures of the visual organ and it is able to induce chronic lesion of the structures of the posterior portion of the eye portion with varying clinical manifestations. Dystrophic changes in infected tissues, the vitreous body and chorioretinal complex in particular, are a result of a chronic inflammatory process.

[The specific features of a structural lesion in the ocular posterior segment in experimental chlamydial infection].

The investigation was undertaken to study changes in the structure of the vitreoretinal complex in experimental chlamydial infection. Six rabbits were inoculated with Ch. pneumonia (6 eyes) and Ch. trachomatis (6 eyes) via instillations, subconjunctivally and intravitreally. Clinical and pathomorphological study was conducted during 128 days, by using immunohistochemical techniques. All modes of inoculation resulted in the development of an intraocular infectious process as uveitis, choriorenitis, and vitreitis (endophthalmitis) of varying degrees--from subclinical to severe. Immunohistochemical study revealed the pathogen in the structures of the ocular posterior segment and in venous blood in all cases. When locally inoculated, chlamydial infection becomes disseminated, by afflicting the ocular posterior segment, no matter what the mode of inoculation is applied. The clinical picture of the lesion widely varies from subclinical manifestations to a severe process.