This review systematizes data on the anatomy of the optic nerve from an applied perspective. It describes in detail the embryogenesis, structure, and topography of each of its four segments (intraocular, intraorbital, intracanalicular, and intracranial). Considerable attention is paid to variations in the relationship between the optic nerve and the sphenoid sinus, taking into account the structural features of the latter. The review presents variations in the frequency of optic nerve types according to M.C. DeLano et al. (depending on their relationship with the sphenoid sinus), including in the presence of optic canal dehiscence, Onodi cells, and pneumatization of the anterior clinoid process; it also describes variants of the topography of the sphenoid sinus and the presence of additional septa within it.
The adverse consequences of friction in biological structures include wear and discomfort. The tribological model of the eye comprises two rubbing surfaces and lubrication provided by the complex composition of the tear film. Eyelid movement corresponds to the hydrodynamic regime of the Stribeck curve. This review considers various components of the tribological system of the visual organ, including the "lid wiper", the structure of the "brushes", the role of the glycocalyx, and tear film components relevant to friction. The study separately analyzes the patterns and mechanisms of friction under dry eye conditions, and presents in detail the effects of contact lenses on the tribological components of the ocular surface. The review identifies a number of conditions and diseases that affect ocular surface wear and microtrauma, and outlines possible directions for the development of tribological analysis in clinical practice and approaches to reducing friction between ocular surfaces.
In modern cataract surgery, the ophthalmologist aims not only to remove the lens but also to optimize the patient's refractive status. Refractive lens exchange allows correction of presbyopia and reduces spectacle dependence, particularly in patients with high myopia who are not suitable candidates for corneal procedures. OBJECTIVE:The study evaluated the postoperative outcomes of trifocal intraocular lenses (IOLs) implantation for correction of high myopia and myopic astigmatism. MATERIAL AND METHODS:This retrospective study, conducted at the Eye Microsurgery Ophthalmological Center in Chișinău (January-December 2023), analyzed data from 40 patients (75 eyes) who underwent refractive lens exchange with trifocal IOL implantation (Alcon PanOptix/PanOptix Toric). The patients were selected according to specific criteria, and all underwent comprehensive preoperative assessment. Surgery was performed by phacoemulsification under local anesthesia, followed by postoperative care. The 1-month follow-up included measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), and corrected intermediate visual acuity (CIVA). RESULTS:The patients included in our study received two types of trifocal IOLs. Alcon IQ PanOptix IOLs were implanted in 81% of cases, and Alcon IQ PanOptix Toric IOLs - in 19%. After surgery, patients showed a substantial improvement in visual acuity: UDVA increased by 81%, UIVA - by 39%, uncorrected near visual acuity (UNVA) - by 12%, and CDVA and corrected near visual acuity (CNVA) - by 2%. Peripheral retinal degeneration was the most common ocular pathology - 47% (35 eyes). CONCLUSION:Trifocal IOL implantation in high myopia with myopic astigmatism provides high visual acuity, spectacle independence, and requires careful preoperative assessment.
Preeclampsia is a leading cause of maternal and perinatal mortality, which makes the search for methods of early preclinical diagnosis highly relevant. Ocular microcirculation, owing to its similarity to cerebral and placental vessels, represents a unique "window" for assessing systemic endothelial dysfunction. The study provides a comprehensive analysis of current data on the association between impaired autoregulation of retinal and choroidal blood flow in preeclampsia and the risk of systemic hemodynamic and cerebrovascular complications. Unlike physiological vasodilation, preeclampsia is characterized by autoregulatory failure, which leads to hyperperfusion and a risk of vasogenic cerebral edema in cerebral vessels, while in the retina it manifests as vasospasm detectable as early as the first trimester. Choroidal changes remain contradictory and reflect complex systemic hemodynamic shifts. Impaired ocular vascular hemodynamics serves as an early marker of systemic endotheliopathy, and its monitoring represents a promising tool for risk stratification of cerebrovascular and long-term cardiovascular complications.
The prevalence of high myopia and primary open-angle glaucoma is rapidly increasing, complicating differential diagnosis because of overlapping morphological changes in the optic nerve head and lamina cribrosa. Both pathologies are accompanied by changes in the optic nerve head and lamina cribrosa, which makes interpretation of optical coherence tomography findings challenging. Analysis of literature sources shows that the most significant criteria include lamina cribrosa parameters (thickness, curvature, deformation index), features of peripapillary atrophy, the pattern of retinal nerve fiber layer thinning, and biomechanical parameters, including corneal hysteresis. Comparison of these signs helps differentiate myopic and glaucomatous changes and improves the accuracy of differential diagnosis between high myopia and primary open-angle glaucoma.
Various spacers are used to achieve a higher position for the lower eyelid and reduce the degree of lagophthalmos in chronic facial palsy (CFP). Most authors consider a hard palate mucoperiosteal graft (HPG) to have major advantages over other spacers, particularly minimal shrinkage in the postoperative period. However, only a few publications report possible HPG shrinkage, and their findings are based on subjective assessments. OBJECTIVE:The study aimed to perform clinical and echographic assessment of the lower eyelid tissues after the use of HPG for the correction of paralytic lagophthalmos (PL). MATERIAL AND METHODS:The study included 30 patients (30 eyelids) with CFP and PL. The work involved measurement of biometric parameters of the palpebral fissure and ultrasound examination of the lower eyelid (high-resolution grayscale B-scan ultrasonography, color Doppler mapping with 3D mode, echodensitometry, and ultrasound biomicroscopy) at 6 and 12 months after HPG placement. RESULTS:We observed significant changes in palpebral fissure parameters and improvement in the state of the cornea. The distance from the corneal light reflex to the lower eyelid margin (MRD2) decreased from 7.0±1.2 to 5.7±0.8 mm (p<0.001) after surgery, and the degree of lagophthalmos decreased from 2.75 [0.5; 6.0] to 1.0 [0.0; 3.0] mm (p<0.001). At 6 and 12 months, HPG thickness changed from 2.89±0.65 to 2.82±0.69 mm (p=0.68), height from 6.01±0.47 to 5.84±0.54 mm (p=0.449), and volume from 0.56±0.05 to 0.52±0.74 cm³ (p=0.398); these changes were not statistically significant. We identified features of HPG vascularization up to 12 months after HPG placement. The study also describes the complications of HPG placement. CONCLUSION:The use of HPG for the correction of PL showed high effectiveness and safety. There was no graft shrinkage during the 12-month follow-up period. The study demonstrates the capabilities of ultrasound methods for assessing the dimensions and biointegration features of HPG.
This review presents epidemiological data on the prevalence, incidence, and main risk factors of microbial keratitis (MK). The study considers the main methods of ophthalmological and laboratory diagnosis, as well as their capabilities, sensitivity, and specificity. The review analyzes the challenges in the etiological diagnosis of MK to determine the optimal approach.
Current trends in the development of vitrectomy systems, particularly vitreous cutters, focus on reducing instrument gauge while maintaining high cutting efficiency and vitreous fragmentation capacity. Pneumatic guillotine vitreous cutters have several design limitations that constrain further improvement of their functional capabilities. The use of ultrasonic energy for vitreous fragmentation represents an alternative direction in the development of vitrectomy. The emergence of microinvasive ultrasonic 25-gauge (25G) vitreous cutters creates the need for a comprehensive assessment of their effect on ultrastructure of the retina. OBJECTIVE:The study investigated ultrastructural changes in the retina of rabbits after experimental microinvasive ultrasonic and pneumatic guillotine 25G vitrectomy. MATERIAL AND METHODS:Rabbits in the main study group underwent microinvasive ultrasonic and pneumatic guillotine 25G vitrectomy. The retina was examined using electron microscopy. The data obtained in the experimental group, in which microinvasive ultrasonic vitrectomy was used, were then compared with the results of the control group, in which 25G pneumatic guillotine vitrectomy was performed. RESULTS:On days 1 and 7, signs of retinal changes were detected in the inner nuclear layer and nerve fiber layer: vacuolization and fragmentation of neuronal cytoplasm, vacuolization of mitochondria, and elements of the rough endoplasmic reticulum. On days 14 and 30, some structural changes persisted - although the severity of the changes decreased. The nature of the changes in the experimental group was comparable with that in the control group and could be attributed not only to the identical effect of fragmentation, but also to nonspecific surgical trauma, hydrodynamic effects of fluid flow, changes associated with preparation of the material for electron microscopic examination, and individual tissue responses. CONCLUSION:The ultrastructural changes in the experimental group were similar in nature and severity to those observed in the control group. Therefore, microinvasive ultrasonic 25G vitrectomy can be considered a safe technology for vitreous fragmentation, with an effect on the retinal ultrastructure comparable to that of the traditional guillotine fragmentation method.
This review analyzes current concepts of the role of the microbiota and microbiome in the physiology and pathology of the human lacrimal drainage system (LDS). The terms are clearly differentiated: microbiota is the collection of living microorganisms, whereas microbiome also includes their genetic material and habitat. The article describes anatomical features of the LDS and involutional changes in adults (atrophy of the lacrimal puncta, canalicular fibrosis, and nasolacrimal duct stenosis), which predispose to tear stagnation and inflammation. The review includes a comparative analysis of the microbiological spectrum in healthy individuals and patients with dacryocystitis and canaliculitis. The composition of the flora was found to differ substantially depending on age (predominance of S. pneumoniae in children versus Staphylococcus spp. in adults) and geographical region. Metagenomic sequencing data (16S rRNA) demonstrate significantly greater microbial diversity compared with conventional culture methods, revealing a broad spectrum of aerobes, anaerobes, and fungi. The work pays particular attention to regional resistance patterns, including the high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in several Asian countries. Based on the literature data this study proposes and algorithm for empirical antibacterial therapy, taking into account the likely pathogens, as well as the indications for surgical correction, and emphasizes the prospects for creating a national map of the LDS microbiome in the Russian Federation to optimize treatment strategies for dacryocystitis and dacryostenosis.
OBJECTIVE:The study aimed to perform acoustic analysis of changes in the lens layers after intravitreal dexamethasone implant injection. MATERIAL AND METHODS:The study included 40 patients (40 eyes). The follow-up period was 6 months. The patients were divided into two groups: group 1 (control) included 20 patients (20 eyes) with a natural crystalline lens who did not receive intravitreal dexamethasone implant injection; group 2 (study group) included 20 patients (20 eyes) with a natural crystalline lens who received one intravitreal dexamethasone implant injection. All patients underwent ultrasound digital scanning in B-mode and 3D color Doppler mapping modes using VOLUSON E8 Expert and VOLUSON E10 ultrasound diagnostic systems. The examination used SP 10-16 MHz and L8-18i-D linear probes, as well as RSP 5-12 MHz and RSP 6-16-D volume probes. RESULTS:This study showed that a single dexamethasone implant injection does not lead to statistically significant changes in acoustic density of the lens layers compared to the control group. However, longitudinal assessment of patients in the study group after a single dexamethasone implant injection revealed a statistically significant increase in acoustic density in the anterior cortical layers (p0-6=0.013), nucleus (p0-6=0.02), and posterior cortical layers (p0-6=0.00) at 6 months. CONCLUSION:The use of acoustic analysis as an objective diagnostic method enhances the informational value of the examination, enabling the detection of lens changes at the preclinical stage and providing a more objective assessment of the dynamic alterations occurring in the context of topical high-concentration steroid application.
High myopia is one of the main causes of reversible vision loss worldwide among the working-age population. Despite the widespread use of phakic intraocular lenses (PIOLs) for correction, immunological changes in the aqueous humor before and after implantation remain insufficiently studied. OBJECTIVE:The study aimed to assess and compare cytokine levels in the aqueous humor before and after implantation of collamer-based and acrylic-based PIOLs in patients with high myopia. MATERIAL AND METHODS:The study included 58 patients (103 eyes) with high myopia scheduled for PIOL implantation. The main group (A) consisted of 36 patients (68 eyes) who received collamer-based PIOLs. The comparison group (B) comprised 22 patients (35 eyes) who received acrylic-based PIOLs. The control group included 20 patients (20 eyes) with emmetropia. Cytokine levels of IL-6, TNF-α, and TGF-β2 were studied only in 18 patients (30 eyes) using solid-phase enzyme-linked immunosorbent assay with special reagents. RESULTS:After implantation of different types of PIOLs, all patients included in the study achieved the desired outcome: residual refractive error (0.75±0.5 D) and visual acuity (0.85±0.17) remained stable during the 24-month postoperative period. Before PIOL implantation, patients with high myopia showed a statistically significant increase in IL-6 concentration - more than 2.5-fold (9.51±0.52 pg/ml vs 3.82±0.26 pg/ml in the control group) (p<0.001). The TNF-α level increased almost 1.8-fold (9.98±0.53 pg/ml vs 5.63±0.42 pg/ml in the control group) (p<0.001). In the main group, the TGF-β2 level was 15.99±1.09 pg/ml, which was 4.1- times higher than the control values (3.88±0.26 pg/ml) (p<0.001). CONCLUSION:PIOL implantation in high myopia is an effective, safe, and reliable correction method associated with marked changes in the local cytokine profile. Collamer lenses induce a less intense inflammatory response and a more active remodeling reaction compared with acrylic lenses.
This literature review analyzes the prospects for the use of depot drug formulations in dacryology. The limited bioavailability of conventional topical agents and the inability to maintain a stable drug concentration on the ocular surface stimulate the development of local controlled-release systems. Punctal plugs and intracanalicular implants, which use hydrogels and biodegradable polymers for prolonged delivery of anti-inflammatory and immunosuppressive drugs, have been studied extensively. Experimental designs include customizable drug-delivery constructs based on photopolymerizable and composite materials, expanding the possibilities of targeted therapy. Despite the obtained results, the potential of depot systems in the treatment of lacrimal drainage system diseases, including dacryostenosis, requires further investigation in clinical studies.
Objective. The study evaluated the effect of combined physiotherapeutic treatment (CPT) on changes in functional retinal parameters after endovitreal surgery of rhegmatogenous retinal detachment (RRD) with a favorable anatomical outcome. Material and methods. The study included 42 patients (42 eyes) diagnosed with primary macula-off RRD with the duration of up to 30 days. After surgical treatment, which included vitrectomy with silicone oil tamponade, the patients were divided into two groups. Group 1 included 23 patients who received a course of CPT on day 5 after surgery; the course comprised respiratory heliox therapy by inhalation of the helium-oxygen mixture Heliox 21, containing 21% O2 and 79% He. After 15 min, endonasal electrophoresis was performed with application of a 1% Semax solution for 10 min once daily; the course consisted of 8 procedures. Group 2 included 19 patients who received nasal instillations of 0.1% Semax drops starting on day 5 after surgery. The follow-up period was 12 months, with control examinations on day 7 and at 1, 3, 6, and 12 months. The functional effectiveness of the treatment was analyzed by data of best-corrected visual acuity (BCVA) and macular light sensitivity, as well as by changes in central retinal thickness and ganglion cell complex. Results. Patients in group 1 showed a higher level of recovery of functional BCVA and fundus microperimetry parameters compared with patients in group 2 by month 6 of the follow-up. Conclusion. The proposed combination of methods is effective and promising for the rehabilitation of patients after endovitreal surgical treatment of RRD, as it promotes more effective recovery of visual function and reduces the risk of complications.
Perimetry with assessment of the light sensitivity threshold and indices of its loss has wide use in ophthalmology. This review considers three diseases in which static perimetry and microperimetry are used and for which outcome data are available — age-related macular degeneration, diabetic retinopathy, and hypertensive retinopathy. Despite differing opinions on the feasibility of using perimetry in the early stages of these diseases, the obtained data differ from normal values. Microperimetry is more often performed in combination with optical coherence tomography of the retina. Since perimetry is a subjective assessment method, its findings should be verified with the data of local bioelectrical potential, or “objective perimetry”.
Non-glaucomatous optic nerve atrophy (ONA) is a polyetiological pathological condition characterized by the loss of retinal ganglion cell axons and structural changes in the optic nerve head. ONA is one of the leading causes of irreversible visual impairment and disability across different age groups. This review presents current data on the epidemiology, clinical and demographic characteristics, pathogenesis, classification, diagnosis, treatment, and prognosis of ONA.
Tolosa—Hunt syndrome (THS) is a rare neuro-ophthalmological pathology caused by nonspecific granulomatous inflammation in the area of the cavernous sinus, which leads to painful ocular motility restrictions and ophthalmoplegia. The disease is characterized by lesions of the III, IV, and VI cranial nerves, with possible extension to branches of the V nerve and oculosympathetic fibers. This review analyses current data on this disease, with emphasis on its clinical presentation, diagnostic criteria and treatment methods. Taking into account the complexity of identifying THS, emphasis is made on the need for careful differential diagnosis with other clinically similar conditions, such as brain tumors, vascular aneurysms, inflammatory processes, etc. Timely detection of the syndrome and initiation of appropriate treatment, including the use of glucocorticoid hormones, can help prevent serious complications in the form of vision loss or permanent impairment of ocular motor function.
Keratorefractive surgical procedures have become widely used in recent years. However, during femtosecond LASIK, a number of intraoperative cavitation-related complications may occur, one of which is the formation of an opaque bubble layer (OBL). This necessitates careful postoperative monitoring of corneal status. One of the most effective diagnostic methods in such clinical situations is corneal confocal microscopy (CCM), which has proven to be a reliable tool for visualizing all corneal layers, including in keratorefractive surgery. However, the characteristics of OBL revealed using this technique have not yet been adequately studied. PURPOSE:This study aimed to evaluate the potential of CCM using an original algorithm for confocal image analysis in patients with and without OBL in randomized groups. MATERIAL AND METHODS:The study included 45 patients (90 eyes) with myopia (mean -5.0 D). Participants were divided into two groups: the study group consisting of individuals with OPL, and the comparison group (patients without this complication). In all cases, visual acuity assessment, refractometry, and CCM were performed with acquisition of images of various corneal layers before femto-LASIK and at 1, 4, 12, and 24 weeks postoperatively. Liner Calculate, a proprietary software program, was used to analyze the dimensions of the OPL zone. RESULTS:Destructive changes in keratocytes were more pronounced in patients with OBL compared to those in the femtosecond LASIK group without the complication. The depth of stromal damage was also increased; blurred cell boundaries and increased size and reflectivity of keratocyte nuclei were observed in all study participants. At 6 months postoperatively, complete restoration of the corneal stromal layers was not achieved in either group. Morphological and structural keratocyte abnormalities persisted by the end of this period, and were more pronounced in patients with OBL. CONCLUSION:The formation of OBL after femtosecond LASIK is associated with more extensive destructive keratocyte changes, which prolongs the corneal stromal recovery period.
Mucopolysaccharidoses (MPSs) are a group of rare disorders caused by inherited defects of lysosomal enzymes, leading to widespread intra- and extracellular accumulation of glycosaminoglycans (GAGs). The use of enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation has significantly reduced the systemic manifestations of MPS but has little effect on the severity of corneal opacity in ophthalmic involvement. Therefore, the choice of the management strategy for patients with these disorders remains a complex and relevant issue. Only a limited number of studies have addressed the treatment of corneal opacity in MPS, and publications by Russian authors on this topic are lacking. We observed 3 patients (6 eyes) with genetically confirmed MPS type VI and corneal opacity. All of them received systemic therapy; however, despite that, functional outcomes did not improve, leading to the need for keratoplasty in one of the patients. This article presents these clinical cases and discusses the therapeutic strategy for corneal opacity in patients with MPS type VI.
Functional and anatomical problems associated with lower eyelid retraction (LER) can significantly affect the patient's vision and quality of life. Numerous methods have been proposed for correcting the position and contour of the lower eyelid; however, surgical management is often challenging and insufficiently effective. One of the widely used approaches is the release of lower eyelid retractors with the use of a spacer graft. This article reviews literature on available spacers for correcting lower eyelid position.
PURPOSE:This study aimed to investigate the local mechanical properties and determine the Young's modulus (Y) of corneal lenticules (stromal layer fragments) using scanning ion-conductance microscopy (SICM) in patients with myopia and myopic astigmatism who underwent femtosecond laser surgery using the corneal lenticule extraction for advance refractive correction (CLEAR) technique. MATERIAL AND METHODS:The study included 19 patients aged 21-48 years, comprising 11 men (58%) and 8 women (42%) (38 eyes), from whom 34 lenticules were extracted. Participants were divided into two groups: group 1 - patients aged 26-36 years, and group 2 - patients aged 41-48 years. The analysis of extracted lenticules was performed 6-10 hours postoperatively. The preoperative, intraoperative, and postoperative parameters were as follows: spherical equivalent from -1.75 to -8.25 D, cylindrical component from -0.0 to -1.75 D, central corneal thickness 511-607 μm, lenticule thickness 78-159 μm, percentage of tissue altered (PTA) index 33.1-47.1, and posterior lenticule surface depth 288-402 μm. RESULTS:In group 1, the Young's modulus values of stromal fibrils (at a depth of 302-402 μm) ranged from 128.7 to 920 Pa, whereas in group 2 (depth 288-377 μm), the values ranged from 252.2 to 641.1 Pa. CONCLUSION:For the first time, the biomechanical properties of the fibrils in the middle stroma were studied in vivo and described using the Young's modulus. Elasticity was higher in the lenticules extracted from patients aged 21-36 years than in those from patients aged 41-48 years.
