[Comparative evaluation of the results of one- and two-piece mushroom keratoplasty]. / Sravnitel'naya otsenka rezul'tatov mono- i dvukhkomponentnoi modifikatsii gribovidnoi keratoplastiki.

PURPOSE: To compare and evaluate the outcomes of one- and two-piece mushroom keratoplasty configurations for various corneal pathologies. MATERIAL AND METHODS: A total of 32 patients (32 eyes) with corneal perforations, descemetocele and deep corneal opacities underwent surgery. Depending on the surgery technique, the patients were divided into 2 groups: group I (17 eyes) underwent manual one-piece mushroom keratoplasty according to our own technique; group II (15 eyes) underwent modified two-piece microkeratome-assisted mushroom keratoplasty according to the technique by M. Busin. All patients underwent clinical and functional studies before surgery and in the course of a 1-year follow-up. RESULTS: Transparent engraftment of the cornea was achieved in 82 and 80% of cases; best corrected visual acuity (BCVA) averaged 0.57±0.19 and 0.53±0.17; spherical component of refraction varied from 1.25 to +5.5 and from 1.25 to 6.0 diopters; mean corneal astigmatism was 3.15±1.73 and 3.21±1.89 diopters in groups I and II, respectively. At 6 months after surgery, the mean endothelial cell density (ECD) was 2336±198 and 2291±175 cells/mm2, at 1 year - 2041±189 and 1955±161 cells/mm2 in groups I and II, respectively. CONCLUSION: One- and two-piece mushroom keratoplasty is effective in surgical treatment of various corneal pathologies ensuring a high rate of transparent corneal engraftment. The revealed risk of false chambers formation between separate parts of the graft after the two-piece method could in most cases be eliminated by re-injecting air into the anterior eye chamber.

[Optical properties of the cornea after different modifications of penetrating keratoplasty]. / Opticheskie svoistva rogovitsy posle razlichnykh modifikatsii skvoznoi keratoplastiki.

PURPOSE: Comparative analysis of optical properties of the cornea after different modifications of penetrating keratoplasty. MATERIAL AND METHODS: The study included 56 patients (56 eyes) divided into three study groups according to the surgery technique. Group I included 17 patients (17 eyes) after one-piece mushroom keratoplasty, group II - 21 patients (21 eyes) after two-piece mushroom keratoplasty and group III - 18 patients (18 eyes) after penetrating keratoplasty. In addition to standard examination methods, before surgery and in the course of the follow-up all patients underwent software-powered corneal densitometry on the anterior segment analyzer (Pentacam HR, "Oculus", Germany), as well as an assessment of the degree and regularity of postoperative astigmatism. RESULTS: Comparison of the obtained results revealed with a high degree of confidence higher values of the total specific light scattering after two-piece mushroom keratoplasty throughout the entire observation period (p<0.05). At the same time, there was no statistically significant difference in visual acuity between the three study groups (p>0.05). A statistically significant increase in the level of induced astigmatism was revealed after penetrating keratoplasty. CONCLUSION: The observed increase in light scattering after two-piece mushroom keratoplasty does not lead to a decrease in visual acuity. The interface in the optical zone of the cornea formed by a microkeratome does not affect the degree and regularity of induced astigmatism.

[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.

[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.

[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.

[Comparative assessment of functional outcomes of different endothelial keratoplasty techniques]. / Sravnitel'naya otsenka funktsional'nykh rezul'tatov razlichnykh tekhnologii endotelial'noi keratoplastiki.

PURPOSE: Comparative analysis of the higher-order aberrations (HOA) of the cornea after endothelial keratoplasty (EK) using DSAEK and DMEK techniques; evaluation of the correlation between higher-order corneal aberrations and functional outcomes of the treatment. MATERIAL AND METHODS: The study included 47 patients (59 eyes). The main group consisted of 35 patients (35 eyes) with bullous keratopathy and Fuchs' endothelial dystrophy; among them, 19 patients underwent endothelial keratoplasty using the DSAEK technique and 16 - DMEK technique. The control group included 12 patients (24 eyes) of corresponding age without corneal pathology. Standard and special examination tests were performed before, as well as 6 and 12 months after the operation, including computed tomography and aberrometry of the cornea using the Pentacam HR system. Same tests were performed in the control group. RESULTS: The values of the main HOA of the anterior corneal surface: RMS coma (Z3±1, Z5±1), RMS spherical aberration (SA; Z40, Z60) and RMS HOA (Z3-6) 6 months after different EK techniques were statistically significantly higher than in the control group. A statistically significantly lower induction of aberrations of the posterior corneal surface after DMEK technique was revealed. Analysis of the final aberration pattern 6 months after surgery did not reveal any statistically significant differences in the values of the main (RMS coma, RMS SA, RMS HOA) total corneal aberrations after DSAEK and DMEK. A negative correlation was revealed between the best corrected visual acuity (BCVA) and HOA; however, it was statistically significant only for individual aberration values: RMS HOA (Z3-6) of the posterior corneal aberrations after DMEK (r= -0.634, p=0.049), and RMS coma (Z3±1, Z5±1) of the cornea after DSAEK (r= -0.57, p=0.042). CONCLUSION: Comparative analysis of total corneal HOA did not reveal a statistically significant difference in the main parameters: RMS coma, RMS SA, RMS HOA in patients after DSAEK and DMEK surgeries. Correlation analysis did not reveal any statistically significant effects of most aberrations on the functional outcomes of the treatment.

[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'.

[Antiangiogenic therapy in the surgical treatment of pterygium]. / Antiangiogennaya terapiya v khirurgicheskom lechenii pterigiuma.

PURPOSE: To evaluate the effectiveness and safety of adjuvant anti-VEGF therapy in the surgical treatment of pterygium, and to determine the indications for its use. MATERIAL AND METHODS: The study included 67 patients (69 eyes) with grade II-IV pterygium. Patients age was 58.8±12.6 years on average. Best corrected visual acuity (BCVA) varied between 0.01 and 1.0 (0.77±0.24). The patients were divided into 3 groups. The first group included 19 patients (19 eyes) with grade II-III pterygium who underwent «bare sclera¼ surgery and used aflibercept as adjuvant therapy. The second group included 21 patients (21 eyes) with grade II-IV pterygium who underwent auto conjunctival grafting surgery with no adjuvant therapy. The third group included 27 patients (29 eyes) with grade II-IV pterygium who had it removed in combination with single-time peripheral lamellar keratoplasty (PLK) and underwent adjuvant aflibercept therapy. RESULTS: Among patients who underwent pterygium excision with adjuvant antiangiogenic therapy there were 5 cases (26%) of relapse during the observation period (23.38±8.96 months), among patients after pterygium excision with auto conjunctival plastic surgery - also 5 cases (24%) of relapse, and among patients who underwent LKP combined with anti-VEGF therapy there was only 1 case (3%) of relapse. Astigmatism has decreased by 0.24±0.5 (p=0.052) in the first group, by 1.21±1.0 (p<0.05) in the second group, and by 1.64±1.54 (p<0.05) in the third group compared with pre-surgical values, thus increasing average BCVA in all 3 patient groups by 0.1±0.13, 0.07±0.11 and 0.15±0.15, respectively. CONCLUSION: The use of anti-VEGF agents as adjuvant therapy in the surgical treatment of pterygium is a safe method of reducing postoperative inflammation, fibrovascular proliferation and, subsequently, the amount of relapses.

[Lamellar keratoplasty in the management of recurrent pterygium]. / Posloinaya keratoplastika v lechenii retsidiviruyushchego pterigiuma.

As it is known, the main problem of surgical treatment of pterygium is associated with high risk of recurrence. Quite a number of surgical techniques now exist, all aimed at pterygium removal and only differing in the method of conjunctival closure following the excision. Due to relatively low recurrence rates, conjunctival or conjunctival-limbal autografts are currently the 'gold standard' of pterygium surgery. The frequency of recurrence is also insignificant in peripheral anterior lamellar keratoplasty, which is rarely performed due to its complexity and the need for donor cornea. However, it is considered to be the method of choice in cases of repeated recurrence as well as in patients with high pterygium activity. This article describes a clinical case of a massive recurrent pterygium (grade IV, activity level 3). The patient has had three previous surgeries (including conjunctival autotransplantation) that yielded no success. By performing large-diameter peripheral anterior lamellar keratoplasty in combination with adjuvant therapy (intraoperative mitomycin C and subconjunctival postoperative aflibercept injections), structural integrity of the cornea was finally restored without further recurrences and visual acuity was increased.

[Recurrent corneal erosion: modern view of the problem]. / Retsidiviruyushchaya eroziya rogovitsy: sovremennyi vzglyad na problemu.

Recurrent corneal erosion syndrome (RCES) is a common chronic disease associated with repeated episodes of epithelial disruption and is characterized by sudden onset of sharp pain in the eye, usually at night or upon waking, as well as redness, photophobia and lacrimation. The cause of the disease is considered to be impaired adhesion of the epithelial layer to the stroma, which is a consequence of abnormal regeneration of the basement membrane of corneal epithelium. A number of biological factors, including inflammatory mediators and proteinases in high concentrations, contribute to the destruction of the formed adhesion complexes. The basis of RCES diagnosis is characteristic medical history and biomicroscopy. An area of epithelium absence can be detected under direct illumination - more often in paracentral view - mainly in the lower third of the cornea, where an area of loose and irregular epithelium with microcysts or grayish inclusions can be seen. There may also be a card-like or «fingerprint¼ pattern. First of all, it is necessary to differentiate RCES from infectious lesions, which require a fundamentally different treatment regimen. It is believed that the first stage of treatment should include lubricants, drugs that promote epithelialization, inhibitors of matrix metalloproteinases and lipases. The «second line¼ of conservative treatment can include blood derivatives. If conservative therapy is ineffective, it is advised to use phototherapeutic keratectomy (PTK) or perform diamond burr polishing of Bowman's layer. The choice of a method for treating recurrent erosion should be based on the effectiveness of drug therapy, frequency of recurrence, duration of the disease, severity of clinical symptoms, availability of specific ophthalmic equipment and experience with it.

[Antiangiogenic therapy in high-risk keratoplasty]. / Antiangiogennaya terapiya pri keratoplastike vysokogo riska.

PURPOSE: To analyze the effectiveness and safety of VEGF inhibitor used to improve keratoconus transplant survival in patients with corneal neovascularization as stand-alone and in combination with laser coagulation of ingrowing vessels before keratoplasty. MATERIAL AND METHODS: The study included 56 patients (56 eyes) with corneal opacifications of various etiology complicated by corneal neovascularization (CNV). The patients were divided into three groups. The 1st group included 27 patients with diffuse CNV who were undergoing an antiangiogenic therapy using anti-VEGF drug, the 2nd group - 14 patients with stem cell CNV who underwent laser coagulation of major corneal vessels combined with subconjunctival administration of drug before keratoplasty; the control group consisted of 15 patients with mixed type CNV who were undergoing conventional treatment without antiangiogenic therapy. RESULTS: During the follow-up (24.5±4.84 months, 4 to 25 months), transplant rejection reaction was recorded in 7 (23%) patients of the 1st group, 5 (35%) patients of the 2nd group and 9 (60%) patients of the control group. CONCLUSION: Subconjunctival administration of Aflibercept as a stand-alone measure and in combination with laser coagulation of ingrowing vessels may increase the chances of transparent transplant acceptance in high-risk keratoplasty.

[Analysis of light scattering ability of the cornea before and after endothelial keratoplasty]. / Analiz svetorasseivayushchei sposobnosti rogovitsy do i posle endotelial'noi keratoplastiki.

PURPOSE: To evaluate light scattering ability of the cornea before and after Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK) endothelial keratoplasty. MATERIAL AND METHODS: The study included 70 patients (70 eyes) who had undergone DSAEK and DMEK (35 patients, 35 eyes in each group). In addition to standard ophthalmological examinations before and during the one-year follow-up after surgery, the patients had their central corneal thickness, stromal thickness, thickness of the interface area and the graft measured with optical coherence tomography (Optovue, U.S.A.). Intensity of light scattering by corneal structures was evaluated using Pentacam HR (Oculus, Germany) topographer with proprietary software and algorithms for calculation of corneal transparency. RESULTS: Comparison of the outcomes revealed that indices of general integral and stromal light-scattering were higher in patients after DSAEK. Integral light scattering in the interface and graft areas in the DMEK group was significantly lower than in the DSAEK group during the whole follow-up period. CONCLUSION: The reason for decrease of visual acuity after endothelial keratoplasty, regardless of the surgery type, may be higher light-scattering ability of patient's corneal stroma due to residual opacifications. Better visual acuity outcomes after DMEK in comparison to DSAEK are associated with higher transparency of the interface and graft areas. The suggested new method of assessing the intensity of light-scattering allows more precise evaluation of the influence of light-scattering ability of the stroma, interface and corneal graft after different modifications of endothelial keratoplasty, considering the respective layer thickness and excluding the influence of light scattering on the air-epithelium interface.

[Refractive changes after different modifications of endothelial keratoplasty]. / Refraktsionnye izmeneniia posle razlichnykh modifikatsii éndotelial'noi keratoplastiki.

PURPOSE: To evaluate changes in clinical refraction after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) and Descemet Membrane Endothelial Keratoplasty (DMEK), and assess their correlation to the thickness of the transplant. MATERIAL AND METHODS: The main study group included 40 patients (40 eyes) after DSAEK and 20 patients (20 eyes) after DMEK, the control group consisted of 20 patients (20 eyes) without any corneal pathologies or history of surgical treatment. In addition to standard examination, patients of the main group had central corneal thickness and transplant thickness regularly measured; they were also monitored by optical coherence tomography (Optovue, U.S.A.), computed tomography and aberrometry of the cornea performed on Pentacam device. The control group had the same examination regimen. RESULTS: Best corrected visual acuity after 6 months was on average 0.2 higher in DMEK patients compared to those who underwent DSAEK; after one year - 0.1 higher. Clinical refraction data shows presence of hypermetropic changes after DSAEK surgery. Induced astigmatism after one year was 0.4 Diopters in DSAEK patients, but did not exceed 0.1 Diopters in DMEK patients. Stabilization of the corneal thickness in DMEK group occurred on the 3-4th month, in DSAEK group - 6-7th month. Certain values of higher-order aberrations (3-6) and root-mean-square deviation (RMS) of the wave-front of anterior corneal surface in DSAEK and DMEK groups were higher than in the control group. Aberrations on the posterior corneal surface in DMEK group were significantly lower than in DSAEK group. There were no statistically significant differences in 'final' RMS higher-order aberrations between DMEK and DSAEK groups.

[Mushroom keratoplasty in rosacea keratitis complicated by corneal perforation (a clinical case)]. / Gribovidnaia keratoplastika pri rozatsea-keratite, oslozhnennom perforatsiei rogovitsy (klinicheskii sluchai).

Rosacea is a polyethiologic chronic inflammatory disease with varying clinical manifestations. It is primarily a dermatologic disease, which often manifests in the eyes affecting eyelids, cornea and conjunctiva. The leading role in the pathological process belongs to disruption of regulatory mechanisms in the vascular, immune and nervous systems. It is accompanied by increased levels of metalloproteinases and vascular endothelial growth factor (VEGF). Treatment depends on the severity of the disease and may vary from hygiene of the eyelid margins and use of artificial tears for dry eye disease management, to antibiotics and anti-inflammatory agents in moderate cases, and surgical treatment in severe or neglected state. A clinical case of severe rosacea shows that keratoplasty with mushroom-shaped profile of the surgical incision helps achieve good functional results and reduce the post-operative rehabilitation time, while significantly reducing the risk of postsurgical complications. Anti-VEGF therapy significantly reduces the risk of histoincompatibility reaction typical for rosacea keratitis.

[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.

[Polishing of Bowman's membrane with diamond burr in the treatment of recurrent corneal erosion syndrome]. / Abrazivnaia shlifovka boumenovoi membrany almaznym borom v lechenii retsidiviruiushchei érozii rogovitsy.

PURPOSE: To study the effectiveness of polishing Bowman's membrane with a diamond burr (DBPBM) in the treatment of recurrent corneal erosion syndrome (RCES). MATERIAL AND METHODS: The study included 22 patients (22 eyes) with RCES aged 20-56 years who underwent our original modification of DBPBM. All patients had keratotopography examined, endothelial cell density measured, and optical coherence tomography (OCT) of the cornea taken before and after the procedure. Additionally, conjunctival scraping, blood test for types I and II herpes (fluorescent antibody method) were performed before the surgery. Post-operative treatment included 1-2 weeks of anti-inflammatory and anti-bacterial steroid therapy, and 6 months of artificial tear Cationorm usage. RESULTS: Rehabilitation of all patients after the procedure went quickly, and no relapses were noted during the follow-up. Complete epithelialization of the area of surgical intervention under soft contact lens occurred over 2-3 days. Epithelial thickness was measured with OCT including epithelial mapping; after the surgery, it was almost even over the entire corneal surface. No complications such as induced post-operative refractive error or corneal haze were registered during the course of the study. Disruption of basal epithelial layer and epithelial basal membrane in the area of erosion relapse detected with scanning electron microscopy confirmed the need for their removal in the course of the surgery. CONCLUSION: Conservative treatment of RCES rarely yields results. Removal of inadequate epithelium and following DBPBM using our original method is a highly effective and accessible procedure for RCES treatment with low risk of complications and relapse.

[Peripheral lamellar keratoplasty in treatment of relapsing pterygium]. / Perifericheskaia posloinaia keratoplastika v lechenii retsidiviruiushchego pterigiuma.

PURPOSE: To evaluate the effectiveness and safety of peripheral lamellar keratoplasty (LKP) for treating relapsing pterygium. MATERIAL AND METHODS: The study was conducted in the period of 2007-2017 and included 84 patients (91 eyes) with stage II-IV relapsing pterygium. Best corrected visual acuity (BCVA) before the surgery was in average 0.65±0.28 (0.01 to 1.0). Astigmatism varied from 0.5 to 6.5 D (mean 3.41±2.06). All patients underwent pterygium removal surgery followed by LKP. The analyzed parameters included visual acuity, refraction error before and after the surgery, frequency of relapses and post-operative complications. RESULTS: The follow-up period was 4 months to 10 years (mean 30.9±25.4 months). BCVA after the surgery was 0.1-1.2 (mean 0.83±0.24), post-operative astigmatism - 0 to 3.5 D (1.08±0.62). BCVA has improved and remained stable in 86 (94.5%) out of 91 eyes, decrease of visual acuity was observed in 5 cases (5.5%). Frequent relapse of pterygium happened in 5 cases (5.5%), was non-progressing and required no surgical treatment. CONCLUSION: LKP is an effective and safe method of surgical treatment of relapsing pterygium that provides good optical, tectonic and anti-relapsing results thanks to barrier properties of the layered transplant.

[Comparative analysis of modern methods of preparing donor material for endothelial keratoplasty]. / Sravnitel'naia otsenka sovremennykh sposobov podgotovki donorskogo materiala dlia éndotelial'noi keratoplastiki.

PURPOSE: To evaluate various methods of stripping Descemet's membrane of a donor corneoscleral flap for Descemet's membrane endothelial keratoplasty (DMEK). MATERIAL AND METHODS: The study included 60 corneoscleral flaps (mean donor age was 62.9 years) from the eye bank of Research Institute of Eye Diseases, which were not suitable for clinical use due to positive serological results. Four alternative methods of donor material dissection in preparation for DMEK were compared: SCUBA (group A), our newly suggested method utilizing intracapsular ring (group B), 'liquid bubble' (group C), 'big bubble' (group D). Parameters under evaluation were mean transplant preparation time, density of endothelial cells before and after dissection, presence of complications during detachment of Descemet's membrane. RESULTS: Mean detachment time in group A was 8.5 min, in group B - 7 min, in group C - 8 min, and in group D - 5 min. Loss of endothelial cells as compared with baseline was in average 10.5% in group A, 9.3% in group B, 10.7% in group C, and 10.3% in group D. Group A had two cases with complications occurring during separation of Descemet's membrane, group B had one such case, group C - 2 cases, and group D - 3 cases. Histologic examination confirmed absence of stromal fibers on the detached Descemet's membrane in groups A, B and C. CONCLUSION: Among the described methods of preparing donor material for DMEK surgery, all except 'big bubble' proved equal in terms of resulting transplant quality. The 'big bubble' dissection technique requires more time to complete, while the resulting transplant has stromal fibers. Our newly suggested method of Descemet's membrane stripping that utilizes intracapsular ring proved safe and effective alternative for preparing donor material for DMEK.

[Compensating the Descemet's membrane defect (a clinical case study)]. / Kompensatsiia defekta destsemetovoi membrany (klinicheskoe nabliudenie).

The article describes a clinical case of Descemet's membrane detachment that occurred during cataract phacoemulsification with implantation of intraocular lens. Significant corneal edema developed in the early post-op period. Considering the ability of endothelium to close its own defects even with large injury area, the patient was followed-up for 2 years. Corneal edema was treated during 4 months and concluded with instillations of osmotic and anti-inflammatory drugs. At 1.5-2 months of therapy, the edema was gradually decreasing, and by the 4th month of the follow-up the cornea was practically transparent. Density of endothelial cells in central cornea, where the Descemet's membrane was absent, comprised 1000 cells/mm2. Further observation revealed cornea staying transparent for 2 years after the surgery. Complete optical recovery of patients with Descemet's membrane defect in this case study is supported by similar clinical cases briefly described in the article, and evidence that structural functional recovery of the corneal endothelial layer is possible even when it has large defects (more than 2.5 mm in diameter).