[Methods of surgical reconstruction of the conjunctiva]. / Metody khirurgicheskoi rekonstruktsii kon"yunktivy.

Reconstruction of the conjunctiva is required for restoration of damaged ocular surface and is an essential part of that process. Traumas, chemical and thermal burns, multiple surgical intervention can seriously damage the integrity of conjunctival tissue and promote the growth of fibrous tissue, scarring of contractures and their shortening, as well as other complications such as trichiasis, erosion and ulcers on the cornea. When a larger area is affected, there may not be enough donor tissue to replace the defect, in which case the tissue grafts are required to be large enough. Modern modifications of surgical techniques and the continued development of tissue engineering, as well as advancements in stem cell research offer promising novel alternatives for solution of those problems. This article reviews the existing surgical methods of conjunctival reconstruction.

[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.

[Diagnosis and treatment of adenoviral keratoconjunctivitis]. / Diagnostika i lechenie adenovirusnogo keratokon"yunktivita.

PURPOSE: To improve the treatment of adenoviral lesions of the eye based on express diagnostics by the fluorescent antibody technique (FAT) and the use of modern drugs. MATERIAL AND METHODS: The study included 184 patients (333 eyes) with various manifestations of adenoviral lesions of the ocular surface, who were divided into two groups: group 1 (149 patients, 196 eyes) - acute form, and group 2 (76 patients, 137 eyes) - long lasting form. Effectiveness of the proposed treatment was evaluated against separate group 3 (controls) consisting of 28 people (46 eyes) with completed acute adenovirus infection, who had previously received antibiotic and corticosteroid therapy in other clinics. Conjunctival scrapings of study patients were examined with FAT in our proposed modification. Study patients received local therapy with modern drugs (Okomistin, Aktipol). RESULTS: FAT detected the adenovirus antigen in 169 cases in group 1 (86%) and in 99 cases in group 2 (72%). Treatment duration amounted to 12±6 days in group 1, 18±8 days in group 2, and 29±7 days in controls. In both study groups, the duration of treatment was significantly reduced in comparison with the controls (p<0.01). Stable clinical effect and complete restoration of visual acuity have been achieved in most cases. There were no allergic and side effects from the therapy. CONCLUSION: Fluorescent antibody technique is a fast and effective way to diagnose adenovirus infection in ophthalmology. In terms of therapy, the use of an antiseptic, an antiviral drug and diluted corticosteroids is the most rational approach.

[Anterior eye segment damage in coronavirus infection (COVID-19)]. / Porazhenie perednego segmenta glaza pri koronavirusnoi infektsii (COVID-19).

Conjunctivitis may appear as the first symptom of the coronavirus infection (COVID-19). In isolated cases, the lesion of the conjunctiva evokes a systemic infectious process. Currently, the conjunctiva is not considered as an area of long-term reproduction of coronavirus, and its damage is caused by hyperproduction of pro-inflammatory cytokines (especially IL-6); development of iridocyclitis and keratoconjunctivitis is also possible. Most often, local corticosteroids are used to treat these processes, although their use requires caution due to the risk of activating secondary infection (herpetic bacterial, fungal), which often develops as a result of immunodeficiency caused both by COVID-19 and the massive corticosteroid and antibiotic therapy employed when the course of the disease is severe. The severe condition of patients, the lung ventilation, and the prone position all contribute to corneal erosions, exposure keratopathy, pseudomonas aeruginosa keratitis and angle-closure glaucoma attacks. The risk of transmission of coronavirus infection during keratoplasty is estimated as minimal.

[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'.

[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.

[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.