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Abstract Spontaneous luxation frequency dependence of the «capsule bag-IOL» complex on the material and weight of the lens A.A. Ivanov , O.P. Mishchenko , T.N. Iureva S. Fyodorov Eye Microsurgery Federal State Institution, Irkutsk Branch, Irkutsk, Russian Federation Irkutsk State Medical Academy of Postgraduate Education – branch of the FSBEI APE RMACPE, Irkutsk, Russian Federation Irkutsk State Medical University, Irkutsk, Russian Federation Relevance.Spontaneous luxation of the «capsule bag – IOL» complex in the long-term postoperative period is a serious complication. The search for regulated risk factors, the limitation of which will reduce the frequency of this complication, is relevant. Purpose. To evaluate association between frequency of spontaneous luxation of the «capsule bag – IOL» complex and the number of surgeries, taking into account the characteristics of the lens. Material and methods. 69 IOLs from 14 medical companies and 2 capsule rings were examined. The weight was determined using trusted torsion scales (accuracy ± 1 mg) under hydration conditions. IOLs were divided into 3 groups: ≤18 D; 18.5–24.0 D; ≥24.5 D. A retrospective analysis of 159 cases of spontaneous IOL luxation into the vitreous body over 13 years (2007–2020) was carried out. Comparison of IOL implantation results/luxation was carried out from 2006 to 2010, taking into account luxations from 2007 to 2020. Additionally, the number of years from IOL implantation to spontaneous luxation, the axial length of the eye, and the presence of pseudoexfoliation syndrome were evaluated. Results. A multiple excess of the weight of hydrophilic compared with hydrophobic IOLs was found in three comparison groups with a comparable refractive power (p=0.0001). Hydrophilic lenses in various groups were 1.5–1.82 times heavier than hydrophobic lenses. Spontaneous luxation of hydrophobic IOLs occurred less frequently by 11.86–49.22% compared to lenses made of hydrophilic materials. Conclusion.The weight of the IOL may play an important role in the pathogenesis of dislocation of the artificial lens. In the future, it is possible to develop recommendations to reduce the risk of luxation of the «capsule bag – IOL» complex in the long term for patients with an initial combination of non-correctable risk factors complicating the condition of the ligamentous apparatus of the lens. Key words: IOL luxation, IOL weight, lens material, hydrophilic or hydrophobic IOLs

Purpose. To summarize the accumulated experience in the field of studying hereditary retinal pigmented dystrophy, including the genetic heterogeneity and phenotypic diversity of RP. Material and methods. To carry out this review, a search was performed for literature sources on the PubMed and Scopus reference databases for the period up to and including 2023. A total of 55 sources related to the review topic were selected and analyzed. Results. Currently, there is an increasing relevance in medical and genetic diagnostics, which in turn leads to an expansion of the spectrum of causal mutations and the active introduction into medical practice of pathogenetic treatment of HRD, including RP. Conclusion. Expanding the known range of causal gene mutations associated with RP, including Asher syndrome, may help in the development of diagnostic, therapeutic, and genetic strategies for patient counseling. The provision of timely medical and social assistance to patients with RP is an important part of the prevention of this disease. Key words: hereditary retinal dystrophy, retinitis pigmentosa, Asher’s syndrome, ophthalmology, genetics

Purpose. To conduct a comparative analysis of cytokine and chemokine concentrations in vitreous and subretinal fluid in patients with rhegmatogenous retinal detachment of various disease duration. Material and methods. 24 patients with rhegmatogenous retinal detachment aged 39 to 60 years (mean age 49.2±5.7 years) were examined and operated. The duration of the disease ranged from 2.5 weeks to 6 months. Intraoperatively, vitreous body and subretinal fluid were taken. The quantitative content of IL-6, IL-8, IL-4, IL-1ß, TNF-α, MCP-1, VEGF in vitreous and subretinal fluid was determined by enzyme immunoassay. Results. The maximum concentration of VEGF was recorded in the vitreous body with a detachment duration of >3 months (3542 pg/ml), the levels in the subretinal fluid were minimal. A significant increase in MCP-1 in the vitreous body in all groups tended to increase with increasing duration of the disease. High levels of IL-6 and IL-8 in the vitreous body, especially in groups with detachment <1 month and >3 months. Peak concentration of IL-1b in the subretinal fluid at detachment <1 month, decrease in late stages. Low levels of TNF-α and IL-4 without significant dynamics. Conclusion. Assessment of cytokine concentrations in the vitreous and subretinal fluid during retinal detachment suggests a different immune response, which may be due to the presence of hematophthalmic barriers, differences in cytokine production and the nature of the pathological process. These differences are important to consider in the treatment of patients with retinal detachment, as they reflect different aspects of the inflammatory and reparative response, and they may be useful for choosing a treatment strategy. Key words: rhegmatogenous retinal detachment, cytokines, vitrectomy.

Purpose. To develop a method for surgical treatment of corneal tissue defects using a complex of corneal lenticules and evaluate its effectiveness in an experiment using laboratory animals by conducting clinical and instrumental studies in dynamics. Material and methods. 20 experimental animals, mature rabbits of the Soviet Chinchilla breed were included in this study. A corneal tissue defect with a diameter of 4.5 mm and a depth of 150–200 microns was formed. The animals were divided into 2 groups: group 1 — keratoplasty of a complex of human lenticules obtained as a result of refractive surgery and previously subjected to removal of cellular material was performed; group 2, the therapeutic keratoplasty was performed with the Alloplant material. Observation period was up to 2 months, the eye condition of the experimental animals was assessed on days 7, 30 and 60. Results. After implantation of the lenticular complex, clinically and according to OCT data, in all cases, there was a complete adaptation of the lenticules in the bed of the tissue defect, including in the case of complete perforation of the cornea with a diameter of 3 mm. By one month, graft epithelialization was achieved, superficial vascularization was observed, and the lenticular complex partially retained its transparency. In 4 out of 20 cases, antibioticresistant microflora developed on the ocular surface, which corresponded to the clinic of infectious keratitis in 1 case, stopped by medication. In experimental animals from group II, the defect was epithelized for up to 1 month, corneal opacity with superficial vascularization was observed in 3 cases, thinning of the stroma in the area of tissue defect modeling persisted despite compensatory epithelial hyperplasia, the Alloplant material was rejected in 8 out of 10 cases within 7 days after surgery. Conclusion. Our proposed method of surgical treatment of corneal tissue defects using a complex of corneal lenticules demonstrated its effectiveness and safety in an experimental study on laboratory animals. Key words: keratoplasty, corneal lenticule, rabbit, experiment

Relevance. The study of the mechanisms of insufficiently rapid achievement of high visual acuity in the early postoperative period in the correction of myopia by the SMILE method is relevant. Purpose. To evaluate changes in corneal densitometry parameters after SMILE and FS-LASIK surgery in patients with moderate myopia. Material and methods. A study of 152 patients with moderate myopia was conducted, 68 were operated by SMILE and 84 – FS-LASIK. All procedures were performed using a VisuMax femtosecond laser and a MEL 80 excimer laser (Carl Zeiss Meditec, Germany). Assessment of visual acuity, corneal structure (OCT, Optovue, USA), corneal densitometry (Pentacam Scheimpflug, Germany) were performed before the operation, on the 1st, 5th day, 3, 6, 12 months after the operation. OCT scans were analyzed using the ImageJ program. Results. Оn the 1st day after SMILE, visual acuity (p=0.01) and transparency of the anterior and middle layers of the cornea were reduced than after FS-LASIK in the zone from 0 to 2 mm (p=0.045, p=0.001), from 2 to 6 mm (both p=0.001). These differences became statistically insignificant 5 days after surgery. By three and six months in the FS-ERASER group, the corneal transparency in the middle layers were reduced in the 0–2 mm and 2–6 mm zones (p=0.0001, p=0.001). In both groups, by 12 months, the corneal backscattering reached the values of the preoperative period (p>0,05). Conclusion. Refractive operations SMILE and FS-LASIK are accompanied by a decrease in corneal transparency, which is restored to preoperative values by 12 months. In the early postoperative period, an increase in densitometry indicators and a slower recovery of visual acuity after SMILE surgery may be due to active remodeling of the interface, which includes fragments of collagen fibrils and cellular components inside the intrastromal space. Key words: SMILE, FS-LASIK, densitometry, myopia

Purpose. To determine the concentration of proinflammatory and proangiogenic cytokines of aqueous humor in patients with primary openangle glaucoma (POAG) before and after trabeculectomy.Material and methods. A prospective clinical study of levels of interleukin 8 (IL-8), interleukin 6 (IL-6), and isoforms of vascular endothelial growth factor (VEGF-A) in the basal tear of patients with POAG before, 3 days and two months after trabeculectomy by enzyme-linked immunosorbent assay (ELISA) was conducted. Kaplan-Meyer analysis was used to assess the hypotensive efficacy of trabeculectomy in groups; ANOVA-test was used to compare cytokine levels (pg/ml). P<0.05 was considered significant. The follow-up period was 5 years.Results. Group 1 (n=29) consisted of patients with complete success of trabeculectomy, group 2 (n=54) consisted of patients with qualified hypotensive success, and group 3 (n=18) consisted of healthy volunteers. Before the surgery, IL-8 level was 501.7±165.4 in group 1, 933.7±272.7 in group 2, 338.28±140.4 pg/ml in group 3. Three days after the surgery, IL-8 level was 325.1±105.7 in group 1 and 389,4±176,7 in group 2. Two months after the surgery, IL-8 level was 243,8±126,7 in group 1 and 231.8±65.7 in group 2. IL-6 level before the surgery was 21.8±8.7 in the group 1, 48.3±13.9 in group 2, and 8.04±4.42 in group 3. Three days after the surgery, IL 6 level was 34.3±19.2 in group 1 and 66.1±18.7 in the group 2. Two months after the surgery, IL-6 level was 13.9±6.05 in group 1 and 23.45±6.14 in group 2. VEGF-A isoforms level before the surgery was 851.4±369.4 in group 1, 895.8±205.7 in group 2, and 164.65±120.7 in group 3. Three days after the surgery, VEGF-A isoforms level was 597.7±224.7 in group 1 and 712.5±305.7 in group 2. Two months after the surgery, it was 698.5±212.7 in group 1 and 795.8±270.9 in group 2. Higher concentrations of cytokines are associated with clinical manifestations of inadequate regeneration syndrome.Conclusion. Aqueous humor outflow formation is accompanied by a cascade of immuno-inflammatory reactions due to the profile of both proinflammatory and proangiogenic cytokines, whose activity is determined by the initially altered body reactivity.

Relevance. One of the conditions for the functional outflow pathways' formation after filtering glaucoma surgeries is the uniform moisture absorption from the filtering blebs, which is provided by the blood and, possibly, lymphatic vessels of the conjunctiva. Purpose. To conduct a structural and molecular assessment of filtering blebs in patients with open-angle glaucoma (OAG) after non-penetrating deep sclerectomy (NPDS) according to OCT data, as well as ultrastructural and immunohistochemical studies. Material and methods. A clinical study of 12 patients with primary open-angle glaucoma (POAG) after NPDS was conducted. In the long-term postoperative period (12–18 months), the level of intraocular pressure (IOP) was determined, the structure of the filtering blebs using biomicroscopy and OCT of the anterior segment of the eye was evaluated, the immunohistochemical study of the filtering blebs' tissue for the expression of podoplanin and ultrastructural analysis of the samples obtained using a laser confocal microscope LSM 710 (Zeiss) was performed. In 8 cases (group 1), these were non-functional scarred filtering blebs, IOP 24.12± 2.24 mm Hg, in 4 cases (group 2) – functional filtering blebs, IOP 15.31± 4.08 mm Hg. Results. During the immunohistochemical examination of the first group patients' conjunctival samples, no vessels with characteristics of the lymphatic system were detected in any case. In each sample of the second group patients' filtering blebs, from 5 to 7 vessels with different variants of podoplanin expression were determined. Conclusion. The aqueous outflow entering the subconjunctival space through the newly created outflow pathway during glaucoma surgery is carried out at the expense of conjunctival lymphatic structures, the condition of which to a certain extent determines the success or failure of the surgery. Key words: non-penetrating deep sclerectomy; open-angle glaucoma; lymphatic outflow; filtering blebs

Purpose.  To  identify the main risk factors and concomitant complications of late spontaneous dislocations of the complex «posterior chamber IOL – capsular bag» into the vitreous body.Material and methods. The study performed an analysis of 223 case histories of patients with late dislocations of posterior chamber IOL within the period 2013-2015. We took into account the gender composition, age of the patients, method of cataract removal, specifications of luxated IOL.Visual acuity, intraocular pressure level and refraction at the moment of the patient’s visit with the IOL dislocation, concomitant ophthalmic pathology were evaluated.Results. In 2013-2015  surgical interventions for cataract  and its complications in case of late IOL dislocations were carried out in 1.15% of cases. Pseudoexfoliation syndrome was initially diagnosed in 85.2% of patients. The average period from the moment of IOL implantation until its spontaneous luxation into vitreous body was 8.78±4.85 years. Uncorrected visual acuity (UCVA) during the visit concerning the IOL luxation was reduced  up to 0.15±0.16. Best corrected  visual acuity (BCVA) to 0.32±0.25 was with a shift of the spherical component in the direction of hyperopia up to 2.04±4.81 diopters, cylindrical component did not exceed -0.40±0.78 diopters. In 59.2% of cases the IOL luxation was accompanied by hydrodynamic disturbances. Therewith, the IOP was compensated with medication in 81.07% cases, antiglaucomatous interventions  were  carried  out  previously in  11.36%  of  cases,  the reposition or replacement of the luxated IOL was accompanied by an antiglaucomatous component in 7.57%.Conclusions. The main risk factor for the dislocation of the complex «posterior chamber IOL – capsular bag» is pseudoexfoliation syndrome causing a weakness and a progredient destruction of the zonular system of the lens. Moreover, the risk factors of late IOL dislocation are axial myopia, vitreoretinal surgery and  glaucoma in  anamnesis. The main complication of late IOL dislocation is a development and progression of hydrodynamic disorders, revealed in 59.2% of patients. Patients with pseudoexfoliation syndrome, operated for cataract, are subjects to a risk of a late IOL dislocation in the capsular bag in the long-term postoperative period, regardless of the IOL type.

Purpose. To evaluate the ultra-bio-microscopic semiotics of internal fistula, which determines the time and indications for laser descemetopuncture after non-penetrating deep sclerectomy (NPDS), as well as a long-term hypotensive efficacy of this type of interventions. Material and methods. A full and recognized hypotensive effect was evaluated in 1000 patients with primary open-angle glaucoma after non-penetrating deep sclerectomy followed by laser descemetogoniopuncture. The group 1 included 500 patients (retrospective study), the group 2 – 500 patients (prospective study). All patients in the postoperative period underwent an ultrabiomicroscopic monitoring with an evaluation of parametric (mm) and morphometric (acoustic density) indices of internal fistula, intrascleral canal, and filtering bleb. Clinical groups were relevant to sex, age, stages of glaucoma and initial regimen of local hypotensive therapy. Follow-up period was 3 years. Results. The UBM semiotics for validity of the internal fistula are determined: a height of 0.8±0.09mm and a presence of micro-fistula after laser descemetopuncture. In the group 1: time of laser descemetopuncture was 3.4±1.9 months, a full hypotensive effect was observed in 59.6% 1 year later, in 24.8% after 3 years. In the group 2: time of laser descemetopuncture was 1.12±0.08 months, a total hypotensive success was determined in 84.8% after 12 months, up to 3 years – in 60.4% of cases. In its turn, an impact of NPDS hypotensive effect was associated with laser descemetogoniopuncture in 100% of cases 1-12 months after surgical stage of operation. Conclusion. The two-stage technology of non-penetrating deep sclerectomy with laser descemetopuncture in the absolute number of cases allows to create a penetrating internal micro-fistula and to exclude its influence on morphogenesis of newly formed aqueous humor outflow pathways. In its turn, it allows to increase a full and recognized hypotensive effect of fistulizing interventions of non-penetrating type.

Volkova and Iureva investigate the morphogenesis of the aqueous humor (AH) outflow pathways and assess the hypotensive effect of the modified implantation of Ex-PRESS mini-shunt. Results show that the indications for the Ex-PRESS implantation are an initially wide profile (430-450 and more) of the open anterior chamber angle or a previously performed laser iridectomy in case of the narrow anterior chamber angle. The creation of unclosing inner fistula is an undoubted advantage of Ex-PRESS implantation.