[Surgical management of infectious keratitis]. / Khirurgicheskie metody lecheniya infektsionnykh keratitov.

Infectious keratitis is one of the most common causes of blindness worldwide. Despite the existence of a wide arsenal of quite effective antimicrobial drugs, some forms of bacterial and viral keratitis are resistant. Advanced acanthamoeba and mycotic lesions of the cornea, as well as mixed forms of infection usually do not respond well to conservative treatment. In the absence of positive dynamics from the applied etiotropic therapy with observed further progression of the microbial process, there is a risk of corneal perforation and spread of infection to the sclera or deep ocular structures with a high probability of irreversible functional disorders or anatomical death of the eye. In such cases, a timely transition to surgical treatment is necessary in order to maintain structural integrity of the eyeball. For this purpose, corneal crosslinking, microdiathermocoagulation, tissue adhesive, autoconjunctival plasty, amniotic membrane, corneoscleral flap coating, various combinations of these methods, as well as therapeutic keratoplasty are used most often in clinical practice. The choice depends on the etiology, size and depth of the lesion, its localization, prognosis of visual outcomes, somatic status of the patient. Therapeutic keratoplasty is the most radical and effective method of surgical intervention that allows eradication of the infectious focus and best possible restoration of the structural integrity of the eyeball. However, in some cases due to inaccessibility of donor material or high risks of the surgery and non-transparent graft engraftment, it is advised to use alternative surgical approaches, and keratoplasty, if necessary, should be carried out for optical purposes at a further, "quiet" period.

[One-piece mushroom keratoplasty outcomes]. / Rezul'taty monokomponentnoi gribovidnoi keratoplastiki.

PURPOSE: To clinically evaluate the results of one-piece mushroom-shaped keratoplasty. MATERIAL AND METHODS: A total of 10 patients (10 eyes) were enrolled, all having corneal perforations and deep stromal opacities with involvement of Descemet's membrane. For transplantation, hypothermic preserved donor corneas with mean endothelial cell density of 2896±327 cells per 1 mm2 were used. Surgical technique. Recipient tissues as well as the graft were cut with the Moria trephine. For that, the 8.5-mm blade was replaced by a 6.5-mm one and vice versa, respectively, with attention paid not to violate the vacuum while making the cuts. RESULTS: Transparent cornea engraftment was achieved in all patients. Best corrected visual acuity averaged 0.55±0.22. Spherical component of refraction varied from -4.25 to +2.75 diopters. Mean corneal astigmatism was 3.35±1.73 diopters. At 6 months after surgery, the mean endothelial cell density was 2355±336 cells/mm2, at 1 year - 2141±304 cells/mm2. CONCLUSION: One-piece mushroom keratoplasty is an effective surgical treatment of corneal perforations and deep stromal opacities with involvement of Descemet's membrane that ensures a high rate of transparent corneal engraftment. The use of the Moria vacuum trephine in combination with blades of different diameters and secure fixation of the vacuum part of the trephine eliminate the risk of the 'mushroom stem' decentration relative to its 'head'.

[A method of treating purulent corneal ulcer in the eyes with neuroparalytical keratitis and lagophthalmos]. / Sposob lecheniia gnoinoi iazvy rogovitsy, razvivsheisia na glazakh s neirotroficheskim keratitom i lagoftal'mom.

PURPOSE: To develop a method for treatment of advanced purulent corneal ulcers in eyes with neurotrophic keratitis that developed as a complication of intracranial pathological processes or brain surgeries. MATERIAL AND METHODS: The study involved 13 patients (14 eyes) that underwent combined surgery - keratoplasty, autoconjunctival flap covering, partial tarsorrhaphy performed simultaneously. Before and after the surgery, patients received frequent instillations of antimicrobial agents and autologous serum. RESULTS: The organ of vision was preserved in all patients, visual function - in 50% of cases, it improved in 35.7% of cases from 0.07±0.05 to 0.26±0.11. Lagophthalmos has decreased from 6.11±0.99 to 2.78±0.62 mm. CONCLUSION: Patients with intracranial lesions and complicated by neurotrophic keratitis and lagophthalmos often develop advanced severe and progressive corneal purulent ulcers, which seldom respond to the most active conservative therapy. Simultaneous surgery that includes keratoplasty, auto conjunctival flap covering and partial superficial tarsorrhaphy is an effective treatment option that helps preserve visual function in such eyes.

[Modern modifications of penetrating keratoplasty with complex operative incision]. / Sovremennye modifikatsii skvoznoi keratoplastiki so slozhnym profilem razreza.

The basic principle of modern keratoplasty is selectivity, i.e. the choice of whether to replace only the affected corneal layer. However, when layer-by-layer and interlayer transplantation is not indicated, the method of choice is conventional penetrating keratoplasty. An alternative can be its modifications with complex profiles of the transplant edges and the bed, which are better justified in terms of pathogenesis. The most popular among them are mushroom, zig-zag and top-hat. These surgeries combine optical benefits of penetrating keratoplasty as they do not involve dissection of the corneal optical zone and can negate - to a certain degree - its main downsides such as low trauma tolerance of the postoperative scar, significant level of postoperative astigmatism, and increased visual rehabilitation time. Mushroom-shaped incisions can be performed manually with a femtosecond laser or a microkeratome, zig-zag incision - only with a femtosecond laser. Considering the diversity of keratoplasty modifications with complex operative incisions, further research is required for evaluation of their clinical effectiveness and analysis of postoperative complications.

[Methods of preserving donor corneas]. / Metody konservatsii donorskikh rogovits.

Corneal transplantation is the most successful and frequently performed allotransplantation procedure. Benign outcome of penetrating and posterior keratoplasty depends on viability of the corneal tissue and presence of the proper endothelial layer, which retaining is one of the main objectives of preservation of donor material. Methods designed to reach this goal may be classified according to storage duration as short-term (storage in a moist chamber), medium-term (hypothermia), long-term (organ cultivation) and unlimited (cryopreservation). While there are reports of successful application of cryo-conserved corneas for penetrating keratoplasty, its use for this type of transplantation is limited due to complexity of the method and very high requirements for the quality of donor material. However, being a method of unlimited storage, it still attracts the attention of researchers. Taking into account the ongoing development of innovative keratoplasty technologies and the tendency for predominant use of layered grafts that in some cases do not need viable endothelium, methods of preservation of such material for anterior lamellar and intralamellar keratoplasties become relevant. In this context, cryopreservation without the use of cryoprotective agents is promising because it allows simple and fast accumulation of large amount of material with long storage time. Further research on the development of preservation methods of the corneal endothelial layer at sub-zero temperatures may allow storing the material by cryopreservation that will be suitable for penetrating and posterior keratoplasty.

[Objective assessment of donor material for penetrating corneal transplantation]. / Ob''ektivizatsiia otsenki donorskogo materiala dlia skvoznoi peresadki rogovitsy.

Reliable suitability evaluation of donor material is the crucial issue of penetrating corneal transplantation. The main parameter to be considered is endothelial cell density (ECD). However, when it comes to practice, one has to admit significant variation in ECD readings of cadaver corneas obtained by different methods. AIM: to investigate discrepancies in ECD measurements and to define objective criteria for the evaluation of a donor cornea before full-thickness grafting. MATERIAL AND METHODS: In a hundred cadaver eyes, discrepancies in ECD measurements by different methods (specular microscopy, confocal microscopy, and keratoanalyzer) were studied and objective evaluation criteria developed along with an optimal algorithm of pretransplantation assessment. Digital fluorescence microscopy was chosen as the reference method. RESULTS: It has been established that a triple measurement average obtained with any of the tested methods is informative enough as to the state of the donor cornea. CONCLUSION: The highest ECD values were obtained with specular microscopy, the lowest - with confocal microscopy. For reliable evaluation of donor corneas, we recommend that the average of a triple ECD measurement be taken using one of the mentioned methods.

[Morphological assessment of lens capsule after different techniques of cataract extraction]. / Morfologicheskaya otsenka izmenenii kapsuly khrustalika posle razlichnykh sposobov ekstraktsii katarakty.

AIM: to evaluate morphological changes in the posterior lens capsule (LC) after different techniques of cataract extraction. MATERIAL AND METHODS: Eight pseudophakic human autopsy eyes were divided into two groups by the technique used for cataract extraction. Group 1 included 4 eyes following extracapsular cataract extraction (ECCE) and rigid IOL implantation. Group 2 included 4 eyes after minimally invasive cataract surgery (MICS) that involves the use of ultrasound energy. Semithin LC sections were polychromatically stained, visually examined, and imaged for further analysis. RESULTS: There were certain common features in clinical and morphological appearances of lens capsules from either group, including fibrous metaplasia of epithelial cells and/or pseudoregenerative Elschnig-Adamuk pearls on their inner surfaces, more significant in the ECCE group. MICS group, however, demonstrated many distinct and previously undescribed changes. In particular, post-MICS LCs looked swollen, flabby, and even amorphous, their architectonics were disturbed and fibers separated forming micro slit-like spaces, which could be a result of acoustic cavitation caused by ultrasound exposure. We have named this morphological type of secondary cataract «hyaloid-like¼. CONCLUSION: Clinical and morphological type of postoperative LC opacification as well as its severity depends, to a certain extent, on the technique used for cataract extraction. Hyaloid-like opacifications are typical of minimally invasive surgery involving the use of ultrasound and often show no 'classic' changes (fibroproliferative and pseudoregenerative). The latter is explained by the fact that the posterior LC, which has lost its biomechanical properties, can no longer be a substrate for proliferating cells.

[Conduit drainage and preserved amnion in pathologies of the cornea concomitant with glaucoma]. / Trubchatye mikrodrenazhi i konservirovannyi amnion pri patologiiakh rogovitsy, sochetaiushchikhsia s glaukomoi.

The authors improved the anterior-chamber bypass technique implemented simultaneously with reconstructive penetrating keratoplasty or with trabeculotomy in order to enhance the efficiency of antiglaucomatous drainage surgeries in organic lesions of the anterior segment of the eye combined with active inflammatory processes in it and concomitant with secondary glaucoma. The use of conduit drainage was supplemented with wrapping the distal end with conserved amnion, which prevented the postoperative obstruction of drainage or its heading in the outward direction. Amnion, exceeding the size of the scleral flap, was placed in trabeculotomy with active inflammatory signs between scleral strata, thus, preventing an excessive postoperative scarring. A total of 45 patients were operated on with the follow-up reaching 3 years. The efficiency of antiglaucomatous interventions made up 88-93% of cases. The suggested new drainage techniques with conserved amnion can be successfully used surgeries combined with keratoplasty as well as in independently in secondary glaucomas of various etiologies and in primary refractive glaucoma.

[The effect of cholesterol oxidation products on the disruption of lipid metabolism and atherosclerotic damage of the aorta in rabbits]. / Vliianie produktov okisleniia kholesterina na narushenie lipidnogo obmena i ateroskleroticheskoe porazhenie aorty u krolikov.

Feeding of rabbits with a cholesterol preparation containing 3-5% of cholesterol autooxidation products promotes elevation of plasma cholesterol and atherogenic low- and very-low-density lipoproteins as well as accumulation of neutral lipids (largely, of cholesterol ether) in hepatocytes and intramural arteries of the myocardium. The development of massive aortic lipoidosis can be also attributed to the intake of relevant products. The similar dose of non-oxidized cholesterol did not induce marked or any changes at all in rabbits lipid metabolism and aortic status. The evidence obtained indicates an essential role of food exogenic products of cholesterol oxidation in mechanisms of hypercholesterolemia development and atherosclerotic involvement of vascular walls.

[Decrease in the degree of lipoid infiltration of rabbit tissues during feeding with cholesterol freed from autoxidation products]. / Snizhenie stepeni lipoidnoi infil'tratsi tkanei krolikov pri skarmlivanii kholesterina, osvobozhdennogo ot produktov ego okisleniia.

Lipid accumulation in the rabbit liver and myocardium has been investigated by histochemical and biochemical methods. The rabbits received cholesterol that contained 5% of autooxidation products or purified cholesterol. Lipid accumulation took place in the liver and intramural myocardial vessels during feeding of rabbits with autooxidated cholesterol. Feeding with pure cholesterol free from autooxidation products caused but slight changes or no changes at all.

[Morphologic features of the endothelial lining of the blood vessels and endocardium]. / Morfologicheskie osobennosti éndotelial'noi vystilki krovenosnykh sosudov i éndokarda.

The endothelial lining (EL) of ventricular endocardium and coronary arteries of a dog, minipig and humans, as well as that of the abdominal aorta of a rat and superior vena cava (minipig) was studied using luminescent microscope in the reflected light after staining of the non-fixed tissue with thioflavine-T and argentation. Marked heterogeneity of the endotheliocytes was shown to be both specific and depending on the localization of the cells in the cardiovascular system. Comparative analysis of EL in different animal species and in man, as well as in different parts of the CVS, indicated the relationship between the cellular morphologic features and local hemodynamics.

[Morphogenesis of early pre-lipid stages of atherosclerosis]. / Morfogenez rannikh dolipidnykh stadii ateroskleroza.

Investigation of early changes in the aortal wall (focal edema of the intima, rhythmic structures, and primary fibrous plaques) in children and young subjects showed the possibility of nonlipidogenic mode of the development of atherosclerotic plaques. The data suggest that an important role in the genesis of atherosclerotic changes in man is played by local alterations of the arterial wall not associated with disorders in the general lipid metabolism. The local damage of the endothelial lining of the arteries in these sites may be very important in their genesis.

[Fibrous lipid plaque formation in young people]. / Formirovanie fibrozno-lipidnoi bliashki u lits molodogo vozrasta.

The study of the fibrous lipid plaque formation in young subjects showed that the proliferation of the smooth muscle cells in the arterial wall intima was the primary process in the genesis of the atherosclerotic lesions. The hypoxic alterations and metabolic deterioration of the vascular wall occur at the sites of the proliferation of smooth muscle cells and focal hyperplasia. This results in the obesity of the smooth muscle cells and increased permeability for plasma proteins, which intensifies even more the focal intimal sclerosis. The necrosis and degradation of the smooth muscle cells "overloaded" with fat in the centre of the plaque result in the release of lipids into the extracellular space and in the formation of atheroma. Further progressing of atheroma occurs due to the involvement of the new "foamy" and smooth muscle cells, located in its periphery, but not due to the immediate lipid deposition from the arterial lumen.

[Arterial endothelium in human atherosclerosis]. / Endotelii arterii pri ateroskleroze u cheloveka.

Endothelium above the lipid streaks, lipid-fibrous and fibrous plaques in the right coronary artery and the brachial artery of 11 cases of sudden death of males and females aged 22-65 was examined in flat film preparations. The foci of atherosclerotic injuries are covered with deendothelized areas, blood platelets, leucocytes, and other blood cells, with clots of vascular smooth muscle cells. The endothelium is considerably changed; these phenomena evidence an injury of the endothelium and its regeneration in zones of atherosclerotic lesions.

[Focal edema of the intima as a preatherosclerotic arterial lesion]. / Ochagovyi otek intimy kak predateroskleroticheskoe porazhenie arterii.

A number of histological, histochemical and immunomorphological methods were used to study focal edema of the aortal intima in children and young subjects and its association with the development of atherosclerotic alterations. The main manifestations of the focal edema of the intima include focal accumulation of insudate consisting of serous or serous-fibrinous liquid, accumulation of metachromatic substances, damage of collagen and elastic fibers, proliferation of smooth muscle cells and their fatty metamorphosis. Later, signs of organization and sclerosis of the edematous zone develop. The following stages of the development of focal intimal edema may be distinguished: simple or serous edema; serous-fibrinous edema; proliferation of smooth muscle cells followed by their fatty degeneration and extracellular release of lipids; organization or sclerosis of the edema focus. It is assumed that late stages of the development of focal edema of the intima are associated with fibrous and fibrous-lipid atherosclerotic plaques.

[Smooth muscle cells of the arteries and arteriosclerosis]. / Gladkomyshechnye kletki arterii i ateroskleroz.

The review presents information on proliferation of smooth muscle cells (SMC) of the arterial wall as the key moment in atherogenesis. Some factors influencing SMC proliferation as well as some aspects of SMC biology the knowledge of which is necessary for better understanding of some current hypotheses of atherosclerosis are considered. SMC proliferation has been recognized as the main cause of atherosclerosis relatively recently. Each of the original theories or hypotheses of the atherosclerosis pathogenesis under consideration is focused on different factors underlying SMC proliferation and deals with the problems the resolution of which helps better understanding of the causes and genesis of this disease.

[Morphological and histochemical changes in the rabbit aorta during exogenous and endogenous hyperglycemia]. / Morfologicheskie i gistokhimicheskie izmeneniia aorty krolikov pri ékzogennoi i endogennoi giperglikemii

Alimentary hyperglycemia and insulin deficiency were accompanied in rats by atherosclerotic affection of the aorta whose degree increased in feeding of cholesterol to such animals. The detected morphological and histochemical changes in the wall of the aorta correlated with the biochemical atherogenic shifts in the blood serum of the corresponding animals groups established earlier.