[Modern techniques and features of selective keratoplasty]. / Sovremennye tekhnologii i vozmozhnosti selektivnoi keratoplastiki.

Selective keratoplasty involves replacing the affected layers of the cornea with similar donor tissue. In case of pathological changes in the middle and posterior stroma, deep anterior lamellar keratoplasty (DALK) is performed. Chronic corneal edema caused by endothelial dysfunction is an indication for endothelial keratoplasty - Descemet membrane endothelial keratoplasty (DMEK) or Descemet Stripping Endothelial Keratoplasty (DSAEK). Compared to penetrating keratoplasty (PK), these operations are characterized by a low risk of damage to intraocular structures and a relatively short rehabilitation period. Complications of selective keratoplasty include the formation of a false chamber between the lamellar graft and the recipient's cornea, ocular hypertension during anterior chamber air tamponade. Persistent epithelial defect can be a sign of primary graft failure in DALK, DSAEK and DMEK. Selective keratoplasty is characterized by a lower incidence of immune rejection than PK. In some cases, DALK can be complicated by corneal changes related to suture fixation of the graft. Long-term postoperative use of topical glucocorticoids can cause ocular hypertension and cataracts.

[Corneal changes in Fuchs endothelial corneal dystrophy and bullous keratopathy]. / Izmeneniya rogovitsy pri endotelial'noi distrofii Fuksa i vtorichnoi bulleznoi keratopatii.

OBJECTIVE: Evaluation of structural and immunohistochemical features of cornea in Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK). MATERIAL AND METHODS: Group 1 - 44 patients (46 eyes) with FECD, group 2 - 42 patients (42 eyes) with BK. All patients underwent keratoplasty. Preoperative anterior segment optical coherence tomography (AS-OCT, RTVue-100, Optovue, USA) was performed. Endothelium-Descemet membrane (EDM) complexes, corneal buttons were obtained intraoperatively. Morphological (H&E staining) and immunohistochemical (primary antibodies to pancytokeratin, vimentin, fibronectin) studies were performed at the light microscope level (Leica DM-2500, Leica Application Suite V4.8, Leica Microsystems, Switzerland). RESULTS: A direct correlation is found between the results of DM analysis in vivo with OCT and ex vivo with light microscopy. DM thickness (AS-OCT) was significantly greater in FECD (23.0 [19.0; 27.0] µm), than in BK (13.0 [12.0; 14.0] µm). Morphological study of EDM and corneal buttons showed similar difference in DM thickness: 17.9 [16.1; 20.0] µm in FECD and 11.9 [11.3; 13.0] µm in BK. Irregular optical density of stroma is a feature of edema and local fibrosis. In FECD and BK pancytokeratin is expressed in epithelial and endothelial cells, vimentin - in keratocytes, macrophages and vascular endothelium, fibronectin - in DM. In FECD, vimentin is expressed in endothelial cells. CONCLUSION: FECD and BK are associated with different DM' and endothelium' abnormalities, which lead to similar changes of stroma and epithelium. AS-OCT is a useful method of FECD and BK in vivo diagnostics and the selection of treatment option.

[Cell cultures - model object for experimental studies in ophthalmology]. / Kletochnye kul'tury ­ model'nyi ob"ekt dlya eksperimental'nykh issledovanii v oftal'mologii.

The article presents results obtained on several types of model cultures. Primary cultures of corneal epithelial cells and fibroblast-like cells from the limbus were obtained from the tissues of the anterior eye segment. Tests were performed on these cultures to determine the cytotoxicity of antiglaucoma drugs and to trial a protection method. In addition, a comparative analysis of the regenerative potential of various blood derivatives was carried out. An in vitro culture of endotheliocytes showed a correlation between the degree of damaging effects of antiglaucoma drugs of various groups and the content of the preservative benzalkonium chloride in their composition. Corneal keratocytes were used to create a cell sheet reflecting the main structural features of the stroma and suitable for biomechanical tests. The antifibrotic activity of the drugs was tested on the culture of fibroblasts from the nasolacrimal duct. The conducted studies demonstrate that cell cultures can be used as an informative model object for researching the pathogenesis of ophthalmic diseases and for testing drugs.

[Morphological characteristics of Descemet's membrane removed during endothelial keratoplasty (case study)]. / Morfologicheskie osobennosti udalennoi pri endotelial'noi keratoplastike destsemetovoi membrany (klinicheskie nablyudeniya).

The two most used modifications of endothelial keratoplasty (EK) are Descemet's membrane endothelial keratoplasty (DMEK) and Descemet's stripping automated endothelial keratoplasty (DSAEK). The leading complication of EK surgeries is graft detachment in the early postoperative period. This article reports on two cases of endothelial graft adhesion depending on morphological characteristics of the Descemet's membrane (DM) removed during EK. In the first case, complete graft attachment to the recipient's posterior stroma was observed after DMEK. Morphological analysis of the DM showed clean stromal surface. In the second case there was a false chamber between the endothelial transplant and the posterior stroma of the patient. OCT scans revealed separate stromal fibers protruding into the false chamber; morphological analysis of the removed DM showed stromal fragments fixed to the anterior surface of the DM. The revealed changes indicate damage to the posterior stroma the suffered received during descemetorhexis, which may be the cause for incomplete graft attachment. Complete attachment after repeated EK (DSAEK) in this case was due to a thin stromal layer on the graft that provided high degree of adhesion to the posterior corneal surface. DSAEK can be indicated as a repeated EK surgery in cases of persistent endothelial graft non-attachment after DMEK.

[Morphological features of the cornea in eyes with pseudophakic bullous keratopathy and Fuchs endothelial corneal dystrophy]. / Morfologicheskie osobennosti rogovitsy pri psevdofakichnoi bulleznoi keratopatii i endotelial'noi distrofii Fuksa.

PURPOSE: To evaluate the morphological features of posterior corneal layers in pseudophakic bullous keratopathy (PBK) and Fuchs endothelial corneal dystrophy (FECD). MATERIAL AND METHOD: The study included 20 patients (20 eyes) aged 73.8±7.8 with PBK and 24 patients (25 eyes) aged 72.5±10.6 with FECD. Central corneal thickness was measured in all eyes before the surgery by anterior segment optical coherence tomography (AS-OCT, RTVue-100, Optovue, USA). All patients underwent corneal transplantation (DSAEK or DMEK). Postoperative donor graft status was assessed as attached or detached by AS-OCT (RTVue-100, Optovue, USA). Specimens of Descemet's membranes (DMs) were obtained intraoperatively and investigated histologically (hematoxylin and eosin staining). Morphometric analysis was performed using optical microscope Leica DM-2500 (Digital Color Camera Leica DFC295) and ImageScope M software. RESULTS: There was no difference in thickness of DMs' prenatal anterior banded layer (2.58±0.49 µm) and postnatal posterior non-banded layer (11.30±2.64 µm) between PBK and normal cornea. In FECD eyes, DM was significantly thickened by additional collagen layer and guttate excrescences (postnatal layer thickness - 16.62±4.34 µm). Morphological study of the DMs of patients with graft detachment in the early postoperative period revealed residual stromal collagen fibrils that were fixed to the area with dense extracellular matrix. CONCLUSION: The study shows that chronic corneal edema is associated with pathological morphological changes in the posterior corneal layers in PBK and FECD. Individual features of the dense extracellular matrix in the DMs may play a key role in the attachment of donor graft to the corneal stroma and affect the postoperative outcome.

[Evaluation of aqueous cytokine levels in eyes with Fuchs endothelial corneal dystrophy and bullous keratopathy]. / Opredelenie urovnya tsitokinov vo vnutriglaznoi zhidkosti pri endotelial'noi distrofii rogovitsy Fuksa i bulleznoi keratopatii.

PURPOSE: To evaluate cytokine levels in the aqueous humor (AH) of patients with Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK). MATERIAL AND METHODS: The study included 74 patients (74 eyes). The first group consisted of 31 patients (72.7±9.2 years) with FECD; the second group included 35 patients (72.4±9.1 years) with BK. The control group comprised 8 patients (74.3±4.1 years) with immature cataract. Before surgery, patients underwent pachymetry of the central cornea (RTvue-100 OCT, Optovue, USA). Patients of groups 1 and 2 underwent endothelial keratoplasty (DSAEK or DMEK), or penetrating corneal transplantation. Patients of the control group underwent phacoemulsification with implantation of intraocular lens. The initial stage of the surgery involved AH sample collection for evaluation of cytokine levels (IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p70), IL-13, IL-17, G-CSF, GM-CSF, IFNγ, MCP-1, MIP-1ß and TNF-α) by fluorescent flow cytometry using the Bio-Plex Pro Human Cytokine Panel, 17-plex (Bio-Rad, USA). RESULTS: Multiplex analysis of the AH content did not show any statistically significant differences in cytokine levels between decompensated FECD and BK eyes. The levels of IL-6, IL-8, GM-CSF, IFNγ, MCP-1, MIP-1ß were significantly elevated in FECD and BK eyes compared with healthy control. An insignificant deviation of IL-4 and IL-13 levels was detected in FECD and BK eyes compared with healthy controls. There were no significant differences in IL-1ß and TNF-α (indicators of acute inflammation) between the study groups. CONCLUSION: The obtained data confirm that FECD and BK are associated with disruption of ocular immune privilege that leads to chronic local inflammation, which in turn causes remodeling of the corneal tissues resulting in fibrosis.

[Molecular genetic aspects of Fuchs' endothelial corneal dystrophy pathogenesis]. / Molekulyarno-geneticheskie aspekty patogeneza endotelial'noi distrofii Fuksa.

Fuchs' corneal dystrophy (FCD) is a common bilateral non-inflammatory endothelial pathology. It is a multigenic disorder with various expressivity, penetrance and population prevalence. This review discusses corneal endothelium pump function, FCD pathogenesis and its known genetic factors.

[Glaucoma surgery: from traditional filtration techniques to modern principles of bioengineering]. / Khirurgicheskoe lechenie glaukomy: ot klassicheskoi pronikaiushchei khirurgii do primeneniia metodov tkanevoi inzhenerii.

The article reviews the history of glaucoma surgery and analyses the connection between the accumulation of knowledge on glaucoma progression and the emergence of effective surgical treatment methods based on glaucoma pathogenesis. It also describes modern principles of preventing filtering bleb scarring. Particular attention is devoted to biodegradable collagen matrix implants.

[Blepharoptosis: diagnostic tests]. / Blefaroptoz: diagnosticheskie testy.

The article discusses diagnostic algorithms for blepharoptosis in patients with Horner's syndrome, myasthenia, chronic progressive ophthalmoplegia, myotonic dystrophy, and acute neurovascular events. Basic methods for evaluating the upper eyelid position and ptosis severity as well as special pharmacologic stress tests to reveal the true etiology of the condition and make the best treatment choice are described.