[Effects of urokinase plasminogen activator on cultured human retinal epithelial cells]. / Vliyanie rekombinantnogo aktivatora plazminogena urokinaznogo tipa na kletochnuyu kul'turu pigmentnogo epiteliya setchatki.

AIM: to study the effects of urokinase plasminogen activator (UPA) on the human retinal pigment epithelium (hRPE) cell culture. MATERIAL AND METHODS: The toxicity of 50 U/ml UPA was studied with the trypan blue exclusion test. Cell migration was assessed by the wound healing and modified Boyden chamber assays. Additionally, cell morphology, trypsin resistance, and Ki67 expression were investigated. RESULTS: Trypan exclusion test did not reveal any cytotoxicity of 50 U/ml UPA against hRPE cells. The agent appeared able to induce cellular cluster formation and increase the number of spindle-shaped cells (6.4±2.4 cells/field and 67.3±3.2 cells/field in the controls and in the presence of 50 U/ml UPA, respectively, p<0.001). Cell migration in the Boyden chamber also showed a statistically significant increase (1.75-fold, p=0.012). Monolayer wounds were found to heal at an accelerated rate (p<0.05). This effect was dose-dependent, just like the increase in Ki67-positive cells (from 2.5 to 50 U/ml). Moreover, there was a reduction in trypsin resistance of the hRPE cells (the number of resistant cells in the control and 50 U/ml UPA cultures was 5.2±1.7 cells/field and 0.46±0.32 cells/field, respectively, p<0.001). CONCLUSION: UPA, at concentrations of 50 U/ml or less, demonstrates no cytotoxicity against the hRPE cells. The effects of UPA on hRPE include stimulation of epithelial-mesenchymal transition, migration, proliferation, and intercellular interaction. At that, changes in migratory and proliferative activity are dose-dependent.

[En face' optical coherence tomography guided focal navigated laser photocoagulation]. / Fokal'naia navigatsionnaia lazernaia koaguliatsiia setchatki s pomoshch'iu OKT-kartirovaniia.

Aim - to prove the feasibility of focal navigated laser photocoagulation (LP) for central serous chorioretinopathy (CSC) that relies only on the data provided by optical coherence tomography (OCT) without considering fluorescein angiography (FA). MATERIAL AND METHODS: Two patients with CSC were treated with focal navigated LP (NAVILAS laser system) basing on macular OCT findings (RTVue 100). Before the procedure, FA was not performed. RESULTS: In both cases the leaking point was recognized by a solitary focal detachment of the pigment epithelium in 'en face' OCT scans. OCT images were then imported into the laser photocoagulator unit and superimposed on the basic image of the fundus, thus, enabling accurate focal LP. In both cases the serous retinal detachment resolved completely within 9-14 days. CONCLUSION: In some CSC patients, 'en face' OCT data allow focal navigated laser photocoagulation without prior fluorescein angiography.

[Dry eye syndrome in patients with primary open-angle glaucoma].

AIM: to determine the frequency and severity of dry eye syndrome (DES) in primary open-angle glaucoma (POAG) patients that are newly diagnosed or already receiving beta blocker instillation therapy. MATERIAL AND METHODS: A total of 127 patients (190 eyes) with POAG were divided into two groups. Group 1 included 55 newly diagnosed patients (88 eyes), group 2-72 POAG patients (102 eyes) instilling timolol 0.5% twice daily into the affected eye. The control group included 20 patients (40 eyes) aged 60-88 years (73.6 ± 9.2 years on average) with early age-related cataract. RESULTS: DES was found in 69 POAG patients (79%) who was just starting their topical hypotensive therapy and 85 of those (84%) under treatment (p = 0.39). CONCLUSIONS: One should take into account when prescribing ocular hypotensive therapy that newly diagnosed POAG patients usually already suffer from a dry eye. The use of topical beta blockers that contain preservatives exacerbates dry eye signs and symptoms in these patients.

[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.

[Tanning lamp radiation-induced photochemical retinal damage].

On the basis of original clinical research a rare case of bilateral retinal damage due to tanning lamp radiation exposure is presented. Along with significant decrease of visual acuity and light sensitivity of central visual field as well as color vision impairment, bilateral macular dystrophy was found during an ophthalmoscopy and confirmed by optical coherent tomography and fluorescent angiography. Intensive retinoprotective, vascular, and antioxidant therapy was effective and led to functional improvement and stabilization of the pathologic process associated with photochemical retinal damage. A brief review of literature compares mechanisms of retinal damage by either short or long-wave near visible radiation.

[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.