Experimental Modeling of Proliferative Vitreoretinopathy. An Experimental Morphological Study.

A model of proliferative vitreoretinopathy induced by simultaneous intravitreal injection of recombinant IL-1ß and platelet concentrate is created and its main morphological manifestations are studied on Chinchilla rabbits. The model reflects pathogenesis of proliferative vitreoretinopathy: epiretinal membrane with the formation of retinal plication, traction detachment of the retina; moderate inflammatory reaction in the uveal tract, in the optic nerve infundibulum, in the vitreous body; intact structural elements of the retina, dissociation of the retinal pigmented epithelium cells with their subsequent migration. The model is adequate to the clinical picture of proliferative vitreoretinopathy in humans, which recommends it for experimental studies of the efficiency of drug therapy and prevention of this disease.

[Intraocular schwannoma case report: clinical and pathomorphological analysis].

The paper presents a complete clinical, instrumental, histopathological, immunohistochemical, cytological, and molecular-genetic testing of intraocular schwannoma in a 13-year-old girl.

[Immunomorphology in the diagnosis of orbital rhabdomyosarcoma].

Immunohistochemistry (IHC) using monoclonal antibodies is presently the most reliable method to verify tumor tissue belonging. The histological diagnosis of rhabdomyosarcoma (RMS) was immunohistochemically confirmed in 7 of 10 orbital neoplasms in children. In 3 cases the diagnosis of RMS was established after IHC study that revealed the atypical tumor cell expression of the muscular antigens--myoglobin, protein Myo D1, actin HHF-35, which is indicative of the rhabdomyogenic genesis of a tumor. IHC data indicated that, no matter what the histological pattern, orbital RMS is characterized by the expression of cytospecific proteins--myoglobin, Myo D1, actin HHF-35, and tissue-specific (intermediate filaments)--vimentin and desmin. The use of appropriate antibodies offers a means of making a histogenetic diagnosis even in cases of the atypical morphological pattern.

[Plasma-modified silicone graft for scleroplasty in progressive myopia]. / Plazmenno-modifitsirovannyi silikonovyi transplant dlia skleroplastiki pri progressiruiushchei miopii.

Plasma-chemical modification of synthetic transplant material (proliferous silicone) intended for scleroplasty in progressive myopia was theoretically substantiated, developed in the experiment and tested in practice. This treatment was shown to enhance the biocompatibility of a graft which tightly joins the sclera through the connective tissue intergrown from the surrounding capsule into the graft. The efficacy of the proposed plasma-modified grafts in stabilizing progressive myopia in 18 patients operated on (33 eyes) aged 6 to 49 years (spherical equivalent myopia degree 3.0-28.0 D) during 3- year followup was 97%. There was an elevation of uncorrected and corrected visual acuity, are active course of the postoperative period.

[Induction of posterior detachment of the vitreous body by intraoperative vitreo-syneresis with injection of water-soluble polymers (an experimental-morphological study)]. / Induktsiia zadnei otsloiki steklovidnogo tela putem intraoperatsionnogo vitreosinerezisa pri vvedenii vodorastvorimykh polimerov (éksperimental'no-morfologicheskoe issledovanie).

The capacity of water-soluble polymers (polyethylenimine, polyvinylpyrrolidone with copolymers) to induce posterior detachment of the vitreous by its rapid condensation (vitreosynerysis) was studied in experiments on 14 rabbits. Histological studies showed that water-soluble polymers specifically react forming complexes with components of the vitreous. The vitreous shrinks under the effect of polyelectrolytes (vitreosynerysis), which leads to its posterior detachment 1.5 h after injection of the polymer into the vitreous cavity: complete detachment was attained in 2 animals and partial in 8. The degree of vitreosynerysis depends on the complex-forming activity of polyelectrolytes towards the vitreous components. Polymers used in our study exerted no toxic or traction effects on the adjacent structures of the eye.

[Experimental study of cytokines complex inhibitory effect on wound healing after glaucoma filtering operations: histopathological and immunochemical findings]. / Ingibiruiushchee vliianie kompleksa tsitokinov na zazhivlenie ran posle glaukomofil'truiushchei operatsii v éksperimente.

Experiments on a model of glaucoma filtering operation in 25 rabbits showed that the natural cytokine complex inhibited the operation wound healing in comparison with the control. The complex was prepared by an original method (culturing peripheral blood leukocytes) at Immunology Department of the Russian State Medical University. Histopathological study revealed delayed formation of cicatricial tissue under the effect of cytokines. Decreased proliferation of fibroblasts and their decreased functional activity (decreased synthetic activity of glycosaminoglycanes and collagen) was detected in cicatricial tissue. Immunohistochemical studies showed that in remote periods (after 3-8 months) type IV membrane collagen formed in new cicatricial tissue, while in the control, types III and I collagens predominated in cicatricial tissue. Immunohistochemical structure of the cicatrix in experiment correlated with fine fibrous structure of cicatricial tissue, characterized by high permeability. Possible mechanisms of the inhibitory effect of the natural cytokine complex on the course of operation wound healing after glaucoma-filtering surgery are discussed.

[Scleroplasty with plasma-modified homoslceral grafts: experimental morphological study]. / Skleroplastika s ispol'zovaniem plazmenno-modifitsirovannykh gomoskleral'nykh transplantantov v eksperimente (morfologicheskoe issledovanie).

Healing of homoscleral grafts treated by gas discharge low-temperature plasma has been studied. Such treatment leads to formation of a modified surface layer in scleral tissue; the presence of such a layer improves the hydrophilic properties and biocompatibility of the sclera, thus promoting better adaptation of the graft to further restructuring and healing during the postoperative period. Experiments on 32 eyes of chinchilla rabbits showed that after scleroplasty with thus treated transplants, complete replacement of fibroblasts and collagen carcass of the graft was observed as early as after 7.5 months (vs. 12 months in the control); the graft was stabilized and tightly grown into the sclera to form a solid sclera-graft complex which fortifies the scleral membrane of the eye. Use of plasma-modified transplants may improve the efficiency of scleroplastic operations in progressive myopia and ocular injuries.

[Reinforcement of the sclera with new types of synthetic materials in progressive myopia]. / Ukreplenie sklery novymi vidami sinteticheskikh materialov pri progressiruiushchei blizorukosti.

The possibility of using a new synthetic material mersilene for scleroplastic operations has been evaluated in experiments and clinical trials were carried out in patients with progressive myopia subjected to sclera fortification. Morphological studies showed the formation of a connective tissue capsule round mersilene; new collagen fibers grow through its cellular structures, thus fortifying the strength of the sclera-graft complex. Clinical results indicate that sclera fortification by a mersilene graft arrested the progress of myopia in almost all (98%) patients by the end of the first year postoperation; by the end of the second year, myopic refraction stabilized in 92% patients. Hence, mersilene transplants are recommended for scleroplasty in progressive myopia.

[The morphological characteristics of the take of synthetic transplants following experimental scleroplasty]. / Morfologicheskie osobennosti prizhivleniia sinteticheskikh transplantatov posle skleroplastiki v éksperimente.

The morphology of taking in of synthetic transplants after scleroplasty is studied in 24 eyes of chinchilla rabbits. Polytetrafluorethylene-based materials (composite filtration fluoroplast membrane--Teflon) and polyester jersey with reticular structure (scleracod) were used for transplantation. Study of two materials showed common processes and differences in the grafts taking in. Implants made of both materials are characterized by good biocompatibility, which prompts further investigation of their probable use in sclera-fortifying treatment of progressive myopia.

[Clinical and histopathological examination of enucleated eyes with contusion ruptures of cornea after radial keratotomy]. / Kliniko-gistopatologicheskoe issledovanie énukleirovannykh glaz s kontuzionnym razryvom rogovitsy posle radial'noi keratotomii.

Histopathological (histological, histochemical, and morphometric) examinations of 8 enucleated eyes with contusion ruptures of the cornea 2-13 years after radial keratotomy showed two patterns of changes caused by contusion and peculiar reparative processes in the keratotomic incisions. A characteristic feature of contusion injury after radial keratotomy is combination of changes typical of contusion and an extensive perforating corneal wound after its rupture along the incisions. Reparative processes in the keratotomic incisions were regarded as incomplete cicatrization resultant from inhibition of keratoblastic activity after a low-traumatic operation. The structure of cicatrice after keratotomic incisions differed from that of corneal cicatrices after cut wounds. The cicatrice consisted of an epithelial plug and stromal par with picrinophilic amorphous filamentous material and individual keratocytes but no proteoglycanes or filamentous matrix. The length of cicatrice was 80-95% of intact cornea thickness. The structure of keratotomic cicatrice implies its insecurity and sensitivity to blunt injury, and therefore patients should be informed of the necessity to avoid injuries.

[Hemocomponent therapy of central involution chorioretinal dystrophy]. / Gemokomponentnaia terapiia tsentral'noi involiutsionnoi khorioretinal'noi distrofii.

Hemocomponent therapy was used in 181 patients (347 eyes) with central chorioretinal dystrophy. Activated autoplasma possessing a marked resorptive effect, consisting in resorption of hemorrhages and exudations on the fundus oculi, was used. Vision acuity improved in 75% of examined eyes by an average of 0.2 diopters.

[Functional and morphological features of vitreoretinal proliferation after penetrating wounds of eye complicated by hemophthalmos (immunohistochemical and electron microscopy study)]. / Funktsional'no-morfologicheskie osobennosti vitreoretinal'noi proliferatsii posle pronikaiushchikh ranenii glaza, oslozhnennykh gemoftal'mom (immunogistologicheskoe i élektronno-mikroskopicheskoe issledovanie).

Comprehensive (optic, electron, and fluorescent microscopy) morphological analysis of vitreous fragments removed in vitrectomy after penetrating wounds of the eye complicated by hemophthalmia showed that blood and damaged cells of pigment-free ciliary epithelium and the glia play an important role in the development of proliferative processes in the ophthalmic cavity. Immunohistochemical studies revealed active expression of immunoglobulins A and G and of HLA-DR antigen on immunocompetent cells and abnormal expression of HLA-DR in pigment-free ciliary epithelium and the glia, confirming the autoimmune origin of inflammatory disorders.

[Scleral fortification in children at high risk of progressive myopia]. / Ukreplenie sklery u detei s povyshennym riskom progressirovaniia blizorukosti.

To improve scleroplasty efficacy in children at a high risk of postoperative progress of myopia the authors have developed a new surgical method involving increase of the transplant size and its preoperative treatment with a foamy composition intended for filling the body cavities. Experimental biomechanical and morphologic studies have demonstrated that such treatment improves the transplant elasticity and strength, provides its better adhesion and fixation to the sclera at the expense of excellent adhesive properties of the foamy composition, and intensifies revascularization and stabilization processes in the connective tissue. Such surgery was effectively performed in 46 patients.

[Morphological features of scleral graft taking after experimental scleroplasty]. / Morfologicheskie osobennosti prizhivleniia skleral'nogo transplantata posle skleroplastiki v éksperimente.

Morphologic examination of a scleral graft taking in after pretreatment with a polymeric composition to fill in the tissues and of an intact one has revealed that pretreatment of the transplant with a recomposition was conducive to a more rapid and tight adhesion of the graft and its joining the host sclera. A scleroplastic effect of this operation is more manifest, this helping reduce the possibility of surgery failures in progressive myopia.