Vitreous Humor Research Articles

Effects of Cold-Storage Temperature on the Accuracy of Death Interval Estimation Using the Thanatochemical Dynamics of Vitreous Humour and Synovial Fluid

Effects of Cold-Storage Temperature on the Accuracy of Death Interval Estimation Using the Thanatochemical Dynamics of Vitreous Humour and Synovial Fluid

Isolated primary vitreoretinal lymphoma (case report)

This case report presents the diagnostic features of isolated primary intraocular lymphoma, which was initially misdiagnosed as neovascular age-related macular degeneration. A comprehensive examination using ultrasound, optical coherence tomography, and fundus autofluorescence revealed changes characteristic of vitreoretinal lymphoma. Molecular genetic analysis of the vitreous body showed the presence of a MYD88 gene mutation and B-cell clonality by immunoglobulin heavy chain (IGH) gene rearrangement tests, which confirmed the diagnosis.

Computed tomographic dimensions and densities of the normal eye in Jeju horses.

This study aimed to describe the computed tomographic (CT) dimensions and the contrast attenuation of the eye in Jeju horses and Thoroughbreds. We evaluated the CT images of 10 Jeju horses and 6 Thoroughbreds without ocular abnormalities to assess the ocular dimensions and contrast attenuation. The following measurements showed significant differences between Jeju horses and Thoroughbreds (P<0.05): the diameters of the lens, globe, posterior segment, orbital fossa, and lateromedial distance of the anterior chamber; and the Hounsfield units of the vitreous body. This study describes the CT anatomical characteristics of Jeju horses and Thoroughbreds and the differences between the two breeds and provides useful information for understanding and evaluating of the eyes of Jeju horses through a CT scan.

Study on the synergistic effect of calcium carbide residue -fly ash enhanced desulphurisation gypsum under high temperature maintenance condition

The preparation of cementitious materials from bulk industrial solid waste is an effective way to replace cement. Based on the multi-component synergistic coupling effect, the influence law of different dosage of fly ash (FA) and calcium carbide residue (CCR) on the performance of flue-gas desulfurization gypsum (FGDG) slurry was investigated, and the hydration process of composite cementitious materials was discussed through the analysis of hydration products, micro morphology and pore structure by the characterisation methods such as XRD, FTIR, MIP and SEM-EDS. The results show that FA incorporation can improve the flow properties of the slurry, and under the action of CCR and FGDG, the alkalinity of the whole system rises, and the FA vitreous body undergoes dissolution corrosion, releasing reactive SiO2 and Al2O3, and forming C-S-H gel and AFt. In addition, some of the tiny FA particles fill up the pore spaces and microcracks, and the structure becomes denser, and all these effects together contribute to the development of the mechanical properties. This research is conducive to the application of new green cementitious materials and promotes the resourceful use of industrial solid waste.

Fluocinolone Acetonide Loaded Chitosan Nanofiber Scaffolds for Treatment of Ocular Disorders: In Vitro Characterization, Ex-Vivo Corneal and Ex-Vivo Scleral Evaluation

Purpose Drugs administered in the ocular region need to overcome ocular barriers without permanently damaging the ocular tissues. Moreover, ocular disorders of the posterior segment are more difficult to treat due to invasive procedures required to reach the posterior segment. Hence, to treat posterior disorders of the eye an attempt was made to develop nanofiber (NF) scaffolds for effective management of chronic posterior uveitis. Nanofibers (NFs) were formulated using the electrospinning technique. Methods NF scaffolds were formulated using the electrospinning technique. The effect of different concentrations of chitosan on NF production was studied by considering different ratios of chitosan (CS) and polyvinyl alcohol (PVA). Physicochemical characterization of NFs was performed to evaluate developed NFs. Results The optimized NF scaffold had a diameter of 129 ± 3 nm. NF scaffolds were found to have a tensile strength of 0.2882 ± 0.078 N/m2, thickness of 0.16 ± 0.05 mm, and drug entrapment of 95 ± 2.0%. The bioadhesive strength of the NF was found to be 257.3 ± 0.04 g/cm2 indicating high bioadhesion of NFs to the ocular tissues. The in-vitro, ex-vivo corneal and ex-vivo scleral drug release after 12 h was found to be 78.4 ± 1.0%, 65.33 ± 0.2% and 78.41 ± 1.0%, respectively. Ex-vivo whole eye model experiment indicated a concentration of about 40 ± 1.75% of drug permeated from corneal layer to the vitreous humor after 12 h. The Hen’s egg test-chorioallantoic membrane study (HET-CAM) study and in-vitro cytotoxicity study on Statens Seruminstitut Rabbit Cornea (SIRC) cell lines indicated that the developed drug-loaded NF scaffolds were found to be non-toxic as compared to pure drug, thus suggesting cytocompatibility. Conclusion Results of HET-CAM, sterility and ex-vivo studies indicate that the developed formulation is non-toxic, sterile, and effective for the ocular delivery of fluocinolone acetonide to the posterior segment of eye.

Terapia biologiczna w leczeniu zapalenia tylnego odcinka błony naczyniowej oka – aktualny stan wiedzy i perspektywy

Posterior uveitis is a serious problem in ophthalmology, threatening visual acuity and eye function. Biological therapy has emerged as a promising tool in the treatment of this disease, offering new paths for intervention. The paper discusses current aspects of biological the rapy in the context of posterior uveitis and development prospects. Posterior uveitis is a group of inflammatory conditions involving the choroid, retina, and vitreous body. The disease manifests itself with various symptoms, including visual impairment and the appearance of spots in the visual field. Posterior uveitis can lead to serious complications such as retinal damage, glaucoma, and loss of vision. Steroid therapy is the mainstay of treatment, but it can cause side effects. In the case of intolerance or recurrence of the disease, immunosuppressive therapy is used. A biological therapy such as adalimumab is currently being used for cases that are resistant to other treatments. At present, in Poland, it is possible to refer patients for treatment in the drug program entitled “Treatment of Uveitis”. Biological therapy offers new possibilities in the treatment of posterior uveitis. Key areas for the development of biological therapy are: precise targeting, targeted treatments, gene therapies and increasing its availability. However, there are challenges related to the potential side effects and costs of biological therapies. This therapy represents a promising approach for the treatment of posterior uveitis, opening the way for more precise and effective interventions in the future.

Angiotensin Converting Enzyme Inhibitors: Interaction Issues in Patients with Glaucoma and Arterial Hypertension. Review

The purpose of the review is to evaluate the interaction of angiotensin-converting enzyme inhibitors in patients with glaucoma and concomitant arterial hypertension using literature data. Glaucoma is the main cause of blindness and visual impairment, as well as the main cause of irreversible blindness worldwide. Pharmacotherapy, laser or surgical treatments are used to reduce IOP levels, as well as prevent deterioration of visual field defects. However, 40 % of patients develop glaucomatous neuropathy despite ongoing therapy. This prompts the investigation of alternative causes of damage to the optic nerve, and abnormal blood pressure levels, both too low and too high, are considered as a possible risk factor. Arterial hypertension occurs in 48–65 % of patients with glaucoma and is the most common systemic disease in patients with glaucoma. Currently, angiotensin converting enzyme (ACE) inhibitors are considered the “gold standard” in the treatment of arterial hypertension, in the pathogenesis of which activation of the renin-angiotensin system (RAS) plays an important role. The renin-angiotensin system (RAS) is a hormonal system responsible for regulating blood pressure and fluid and electrolyte balance in the body. Local tissue-specific RAS were found, including in the structures of the eyeball: cornea, aqueous humor, iris, ciliary body, vitreous body, retina. These data indicate that the local RAS plays an important role in the regulation of the physiology of the eye and may become a target in the development of new antiglaucoma drugs. Animal studies, as well as studies in various patient groups, show that systemic antihypertensive drugs that inhibit the RAS, such as ACE inhibitors, reduce IOP. These studies support the concept that RAS inhibitory drugs may be potential antiglaucoma drugs in the future, as ACE inhibitors can improve the outflow of intraocular fluid, thereby reducing IOP.

Pathogenetic Aspects of the Development and Course of Rhegmatogenous Retinal Detachment against the Background of Proliferative Vitreoretinopathy. Literature Review

Retinal detachment (RD) is the most serious problem of modern ophthalmology, often leading to a decrease or irreversible loss of visual functions. The literature review is devoted to the latest trends in the study of the mechanisms of development and course of rhegmatogenous retinal detachment (RRD) against the background of proliferative vitreoretinopathy. In the pathogenesis of RD, there are five theories, as well as nine main risk factors for development. It is known that the contact between the retinal neuroepithelium and the retinal pigment epithelium is maintained by physical and metabolic forces, as well as by the friction force of the outer segments of photoreceptors and RPE cells. With synchisis and simultaneous syneresis, vitreous detachment develops, with increased traction forces and the possible development of RRD. Retinal detachment is the most serious problem of modern ophthalmology, often leading to a decrease or irreversible loss of visual functions. The review of the literature is devoted to the latest trends in the study of the mechanisms of development and course of rhegmatogenous retinal detachment against the background of proliferative vitreoretinopathy. In the pathogenesis of RD, there are five theories, as well as nine main risk factors for development. It is known that the contact between the retinal neuroepithelium and the retinal pigment epithelium is maintained by physical and metabolic forces, as well as by the friction force of the outer segments of photoreceptors and RPE cells. With synchisis and simultaneous syneresis, vitreous detachment develops, with an increase in traction forces and the possible development of RRD. The presence of a retinal tear rarely leads to RRD. It has been established that a pronounced traction effect, rather than a through rupture of the retina, is a key factor in the development and progression of RRD. Traction occurs in the course of proliferative vitreoretinopathy and the epiretinal layer of the vitreum remaining in the posterior vitreous detachment. With the development of detachment, damage to the hematoophthalmic barrier occurs, leading to the release of cells into the vitreous cavity that affect the development of PVR (epi-, sub- and intraretinally) with the formation of an epiretinal membrane. At the same time, communication with the choroid is lost, hypoxia and acidosis develop. ERMs formed during retinal detachment include glial cells and their subtypes — fibrous astrocytes, Muller cells, microglia, hyalocytes, RPE cells, fibroblasts and myofibroblasts. However, the leading role in the formation and development of ERM belongs to Muller cells and astrocytes. Also involved in the pathological process of ERM formation are: transforming growth factor β2, fibroblast growth factor, nerve growth factor, vascular endothelial growth factor, platelet growth factor, laminin, fibronectin, thrombospondin-1, osteonectin, transcription factor. Against the background of ROS, one should not forget about the change in the chemical composition of the vitreous body (increased content): serum albumin, transferrin, antithrombin III, α1-antichymotrypsin, α1-antitrypsin, α2-HS-glycoprotein, hemopexin, transthyretin, apolipoprotein A1, and fibrinogen

Studying the Interaction of Viteral Substitutes with the Surface of Acrylic Intraocular Lenses

Purpose of the study: In vitro to study the degree of adhesion of vitreous substitutes, such as silicone oil of various viscosities and perfluorodecalin (PFOS), to hydrophobic acrylic polymer IOLs and evaluate the interaction of vitreous substitutes with the model MIOL-Soft-23 in the clinic. Material and methods. IOLs of the model MIOL-Soft-23 were taken for the experiment. MIOL-Soft-23 are included in the RPR-20 set. IOL of the model MIOL-Soft-23 is made by photopolymerization from a biocompatible spatially cross-linked hydrophobic acrylic polymer based on oligomers and monomers of the methacrylic series with filters in the ultraviolet region of the spectrum from 19 to 23 D. For the experiment, silicone oils of different viscosities were taken: RS-OIL 2000 (Alchimia), SIL-5000-S (DORC), Oxane 5700 (Bausch &amp; Lomb), PFOS (perfluorodecalin) Dk-line (Bausch &amp; Lomb). Also, saline sodium chloride 0.9 % (Solofarm) was used. Results. Revealed a decrease in the degree of silicone adhesion to the surface of acrylic hydrophobic IOLs as the temperature rises, not less than 1.5 %. The absence of dependence of the degree of adhesion on the degree of viscosity of silicone oil was confirmed, which corresponds to the literature data. For the first time, the average percentage of adhesion of perfluorodecalin to the IOL surface data were obtained, in particular, the MIOL-Soft-23 model. The range of values ranged from 0.7 to 7.2 %. The average coverage percentage is 1.9 ± 1.3 % (exposure at 37 ± 1 °C for up to 14 days) and 3.4 ± 1.5 % (exposure at room temperature for up to 14 days). This confirms the need for careful intraoperative monitoring of the completeness of removal of PFOS droplets from the IOL surface. Conclusion. The presence of the risk of adhesion of residual drops of silicone oil and PFOS to the surface of the IOL necessitates careful intraoperative control of the completeness of the removal of vitreous body substitutes, as well as further search for the best ways to eliminate this complication. The conducted complex of studies makes it possible to recommend the use of IOL model MIOL-Soft-23 in complicated cases of vitreal surgery.

Age-related changes on physicochemical properties of the artificial vitreous humor: A practical tool for enhancing ex vivo studies

The vitreous humor (VH) is a hydrophilic, jelly-like ocular fluid, which is located in the posterior chamber of the eye. The rheological, structural, and chemical properties of VH change significantly during aging, which further causes eye-associated diseases and could be a potential indicator for various diseases. In this study, artificial VH (A-VH) samples were created by taking into account different age groups to observe age-related changes in the physicochemical properties of these samples. This study aimed to measure the physicochemical properties of age-dependently prepared A-VH samples to determine the changes with aging in the physicochemical properties of A-VH samples.Phosphate-buffered saline (PBS)-based A-VH samples were prepared in three types representing adult, middle-aged, and elder individuals. Age-related changes in physicochemical properties (surface tension, osmolality, pH, relative viscosity, density, and refractive index) were analyzed by related equipment.The A-VH samples, prepared using PBS, showed strong similarity to authentic VH in terms of physicochemical properties. While the age-related changes studies have revealed some discrepancies between age-dependently prepared A-VH samples in terms of surface tension, osmolality, relative viscosity, and pH with high correlation coefficients (r2 > 0,94), density and refractive index values did not show any significant differences and correlation between types of A-VH representing 3 age groups.In conclusion, age-dependent A-VH samples were created successfully to use ex vivo method development studies, and the influence of aging on the physicochemical properties of VH was demonstrated as well.

Cytokines in Immune-mediated "Non-infectious" Uveitis.

Uveitis is a significant cause of ocular morbidity and accounts for approximately 5 - 10% of visual impairments worldwide, particularly among the working-age population. Infections are the cause of ~ 50% cases of uveitis, but it has been suggested that infection might also be implicated in the pathogenesis of immune-mediated "non-infectious" uveitis. There is growing evidence that cytokines (i.e., interleukins, interferons, etc.) are key mediators of immune-mediated "non-infectious" uveitis. For example, activation of the interleukin-23/interleukin-17 signalling pathway is involved in immune-mediated "non-infectious" uveitis. Studies in animal models have been important in investigating the role of cytokines in uveitis. Recent studies of clinical samples from patients with uveitis have allowed the measurement of a considerable array of cytokines even from very small sample volumes (e.g., aqueous and vitreous humour). The identification of complex patterns of cytokines may contribute to a better understanding of their potential pathogenetic role in uveitis as well as to an improved diagnostic and therapeutic approach to treat these potentially blinding pathologies. This review provides further insights into the putative pathobiological role of cytokines in immune-mediated "non-infectious" uveitis.

DNA Content of Various Fluids and Tissues of the Human Body.

Due to the scarcity of literature data on the DNA content of different human tissues, this study aimed to isolate DNA from different tissues and fluids of the human body together with the determination of its content in the samples studied. Material was collected and tests were performed between 1990 and 2010, during autopsies performed for prosecutor's offices in the Department of Forensic Medicine. Goiter and thyroid cancer tissues were obtained from the Department of General Surgery, Gastroenterology and Endocrinology of Wroclaw Medical University. Isolated samples were measured spectrophotometrically, yielding an R 260/280 nm between 1.5 and 1.6. In some cases (when a sufficiently pure preparation could not be obtained), isolation was continued using the silica-based commercial QIAquick PCR Purification Kit (Qiagen). If the sampling tissues showed signs of decomposition such as bad odour or colour, the results were calibrated by Real-Time PCR, using the Quantifiler DNA assay (Thermo Fisher Scientific, Applied Biosystems). The results have shown that the maximum amount of genetic material was obtained from hair roots, adrenal glands, gonads and lymph nodes. The lowest DNA content per gram or milliliter of tissue or body fluid was found in adipose tissue, blood, saliva, bile, sweat, tears and the vitreous body of the eye. The presented findings indicate the best sources of high-quality DNA from the human body: gonads, kidneys, muscle (including heart), blood and bones (after decalcification).

Кровоизлияния в сетчатку у новорожденных. Клинические особенности и факторы риска

Material and methods. The study included newborns born at the Perinatal Center of St. Petersburg State Pediatric Medical University in the period from July 2021 to October 2022. Anamnestic and other risk factors for the development of retinal hemorrhages were assessed in newborns with and without retinal hemorrhages (RH). Depending on the severity of RH (according to the results of the examination on the RetCam retinal camera), the newborns were divided into groups in which the bilaterality of the RH was assessed, localization in the layers and area of the retina, with an emphasis on the macular region and the optic disk. Results. Of the 75 newborns, 16 had birth-related RH (23.1%). Normal spontaneous vaginal delivery showed the highest association with RH (odds ratio, 5.515; 95% confidence interval, 1.15–26.46, p&lt;0.001). Hemorrhages were more often bilateral (68.8%), intraretinal (87.5%) and localized in the central zone of the retina (81.3%). At the same time, severe RH were more often located in zones I and II, in each newborn they affected the optic nerve or macula, in 6.3% of cases they spread to the vitreous body, and in 25% they were accompanied by Roth’s spots. Conclusion. RH occur in 21.3% of full-term newborns and are largely associated with normal delivery. The main characteristics of hemorrhages in newborns differ notably depending on their severity. Severe retinal hemorrhages in newborns may have negative consequences for the development of visual functions at an older age, which requires further long-term studies. This study confirmed that the digital wide-angle retinal camera is an effective method for examining a large number of newborns with RH. Key words: newborn, retinal hemorrhages, vitreous hemorrhages, Roth’s spots

Tegumental topography and molecular characterisation of two trematodes (Platyhelminthes: Digenea) from Clarias gariepinus (Burchell, 1822) in Kenya

The discoveries of new taxonomic features of digenean species through the application of contemporary techniques, such as scanning electron microscopy (SEM) and molecular analysis are still growing. Two species of trematodes Glossidium pedatum and Tylodelphys mashonensis from the intestine and vitreous humour of Clarias gariepinus were recovered from Lake Ol’Bolossat, Kenya. The two endo-helminths were prepared for morphological examination using SEM and molecular characterisation. Additional morphological features were observed for G. pedatum such as domed papillae in the anterior extremity and a protruding cirrus which was unarmed, laterally folded and with a blunt tip as the first such observation for the genus and led to additional characteristics of the diagnosis of the genus. Tylodelphys mashonensis was characterised by a round oral sucker and tribocytic organ rounded with rows of papillae symmetrically arranged. The molecular analyses using ribosomal marker 28S large subunit (LSU) rDNA and mitochondrial (mtDNA) cytochrome c oxidase subunit 1 (cox1) for both G. pedatum and T. mashonensis confirmed the identity of the species and their phylogenetic relationship within the subclass Digenea. This study provides the first mitochondrial (mt)DNA sequence for G. pedatum and also extends the geographical record of two parasites to Kenya.

Congenital cataract associated with COVID-19 infection

AIM: To describe cases of COVID-19-induced congenital pathology of the lens and eye in children.&#x0D; MATERIALS AND METHODS: Nine children (9 eyes) aged 3–6 months with congenital cataract (СC), whose mothers had COVID-19 during pregnancy, were examined.&#x0D; RESULTS: All children had unilateral CC, with heterogeneous turbidity. Changes in the shape, volume, and structure of the capsule sac were often combined with microphthalmia (66.7%) and primary persistent vitreous body syndrome (PPGST) (88.9%).&#x0D; CONCLUSION: The results revealed the possibility of the unilateral development congenital pathology of the lens with the presence of concomitant pathology: microphthalmos, PPGST syndrome in children born to mothers who had SARS-CoV-2 infection during pregnancy. Given the risk of transplacental transmission of the coronavirus from a pregnant woman to a fetus with СC development, these children need a more detailed examination in the first month of life for timely detection of pathology and provision of treatment. Surgical treatment of this pathology often requires a nonstandard individual approach to each stage of the operation and management of the postoperative period.

Анализ эффективности анти-VEGF терапии диабетического макулярного отека в авитреальных глазах

Aim. To analyze the clinical efficacy of anti-VEGF therapy for diabetic macular edema (DME) in avitreal eyes. Methods. 34 patients (38 eyes) with vitreous loss and DME on the background of preproliferative diabetic retinopathy (PPDR) (18 eyes) and proliferative diabetic retinopathy (PDR) (20 eyes) were examined in the main study group. The comparison group consisted of 40 patients (40 eyes) with native vitreous body and DME on the background of PPDR (20 eyes) and PDR (20 eyes). Intravitreal injections of Lucentis 0.5 mg (IVIL) were carried out according to «three monthly injections» scheme, then – to «on demand» scheme. Results. Complete regression of DME in avitreal eyes occurred in 74 % of cases; in eyes with native vitreous body – in 75 %. The duration of postoperative reaction in eyes with vitreous loss was up to 10–14 days, compared with 1–3 days in eyes with native vitreous body. The results of the study revealed that number of IVIL was significantly less in patients with DME on the background of PPDR than PDR. Conclusion. Presence of local neuroepithelial detachment on the background of diffuse DME is prognostically favorable factor for anti-VEGF therapy. The effectiveness of IVIL in DME treatment is comparable in eyes with native vitreous body and avitreal eyes. Key words: diabetes mellitus; diabetic macular edema; preproliferative diabetic retinopathy; proliferative diabetic retinopathy; avitria; Lucentis intravitreal injections.

Empagliflozin targets Mfn1 and Opa1 to attenuate microglia-mediated neuroinflammation in retinal ischemia and reperfusion injury

BackgroundNeuroinflammation and mitochondrial dysfunction play crucial roles in retinal ischemia and reperfusion (IR) injury. Recent studies have identified mitochondrial function as a promising target for immunomodulation. Empagliflozin (EMPA), an anti-diabetic drug, has exhibited great potential as both an anti-inflammatory agent and a protector of mitochondrial health. This study aimed to assess the therapeutic efficacy of EMPA in retinal IR injury.MethodsTo evaluate the protective effects of EMPA, the drug was injected into the vitreous body of mice post-retinal IR. Single-cell RNA sequencing (scRNA-seq) analysis was conducted to uncover the underlying mechanisms, and the results were further validated through in vivo and in vitro experiments.ResultsEMPA effectively protected retinal ganglion cells (RGCs) from IR injury by attenuating local retinal inflammation. The scRNA-seq analysis revealed that EMPA downregulated the nucleotide-binding domain and leucine-rich repeat containing protein 3 (NLRP3) signaling pathway and restored mitochondrial dynamics by upregulating the expression of mitochondrial fusion-related genes, Mitofusin 1 (Mfn1) and optic atrophy 1 (Opa1). These findings were further corroborated by Western blotting. In vitro experiments provided additional insights, demonstrating that EMPA suppressed lipopolysaccharide (LPS)-induced cell inflammation and NLRP3 inflammasome activation. Moreover, EMPA enhanced mitochondrial fusion, neutralized mitochondrial reactive oxygen species (mtROS), and restored mitochondrial membrane potential (MMP) in BV2 microglia. Notably, genetic ablation of Mfn1 or Opa1 abolished the anti-inflammatory effects of EMPA.ConclusionsOur findings highlight the positive contribution of Mfn1 and Opa1 to the anti-inflammatory therapeutic effect of EMPA. By restoring mitochondrial dynamics, EMPA effectively mitigates microglia-mediated neuroinflammation and prevents RGC loss in retinal IR injury.

A clinical case of metastatic ophthalmia against the background of a severe course of new coronavirus infection

The article presents a clinical case of severe bilateral metastatic ophthalmia caused by a bacterial infection against the background of a new coronavirus infection. In a female patient with a new coronavirus infection and viral pneumonia against the background of a septic condition signs of a liver abscess were revealed and a clinic of bilateral endogenous endophthalmitis developed. Despite intensive antibacterial therapy, the clinic of panophthalmitis of the left eye developed, the left eye was eviscerated. The same pathogen Klebsiellae pneumonia was isolated in vitreous body culture of the removed eye, conjunctiva smear and pus exudate from liver abscess. Bilateral metastatic ophthalmia was caused by the presence of an infectious focus in the body (liver abscess) on the background of weakened immunity due to severe septic condition of the patient. In turn, coronary viral infection led to severe respiratory tract damage and development of secondary immunodeficiency. The low effectiveness of intensive antibiotic therapy is associated with this. The rare case of bilateral metastatic ophthalmia described by us is of interest for ophthalmologists in terms of the possibility of such a serious complication caused by the bacterium Klebsiellae pneumonia, combined with liver abscess. At as-association of this pathology with severe coronavirus infection complicates the course, therapy and prognosis of this disease.

Exploring the involvement of the alternative complement pathway in non-infectious uveitis pathogenesis.

Non-infectious uveitis is a complex disease characterized by intraocular inflammation of the uveal area and the leading cause of vision impairment and blindness in young people globally. However, what triggers inflammation and contributes to its recurrence remains unclear. The complement system has been linked to various immunological and inflammatory conditions. In the present study, we have systematically evaluated the role of the alternative complement pathway in the pathogenesis of non-infectious uveitis. Quantitative PCR was done in the peripheral leukocytes to study the expression of genes and regulatory miRNA in both anterior and posterior uveitis (n=28 in each category). Multiplex ELISA was performed to measure alternative pathway complement components, such as C3b, factor B, and CFH, and aqueous humor of infectious and non-infectious uveitis patients and non-inflammatory controls (n=10 each). Western blotting was done to validate the ELISA findings in a subset of patients and controls. Downregulation of C3 and CFH mRNA in the peripheral blood was shown by quantitative PCR in the group of anterior uveiits (AU), while the opposite result was found in the group of posterior uveitis (PU). ELISA levels of C3b and CFH proteins were significantly higher in aqueous humor of infectious and non-infectious uveitis (*p = 0.03 and **p = 0.0007 respectively) as compared to the control group. Western blotting further validated (VitH) the activation of the complement cascade in the aqueous (AH) and vitreous humor of patients with non-infectious uveitis, with an increased level of C3b (n=6) and CFH (n=4) in aqueous humor. C3b level was significantly increased while CFH was reduced relative to controls in the vitreous humor (VitH) of posterior uveitis patients compared to controls (n=27 in each category). A C3b to CFH ratio was computed to assess the regulation of complement activation and this index was several folds higher in both anterior and posterior uveitis (n=10 each). The expression of miRNA-hsa-miR-146a and miRNA-hsa-miR-155-5p that regulates CFH was downregulated and nicely correlated with the increased complement proteins in both anterior and posterior uveitis (n=10 each). Our results demonstrate a clear role of CFH and the activation of the alternative complement pathway in the pathogenesis of non-infectious uveitis; however, its therapeutic potential warrants further investigations.

Bridging Retinal and Cerebral Neurodegeneration: A Focus on Crosslinks between Alzheimer-Perusini's Disease and Retinal Dystrophies.

In the early stages of Alzheimer-Perusini's disease (AD), individuals often experience vision-related issues such as color vision impairment, reduced contrast sensitivity, and visual acuity problems. As the disease progresses, there is a connection with glaucoma and age-related macular degeneration (AMD) leading to retinal cell death. The retina's involvement suggests a link with the hippocampus, where most AD forms start. A thinning of the retinal nerve fiber layer (RNFL) due to the loss of retinal ganglion cells (RGCs) is seen as a potential AD diagnostic marker using electroretinography (ERG) and optical coherence tomography (OCT). Amyloid beta fragments (Aβ), found in the eye's vitreous and aqueous humor, are also present in the cerebrospinal fluid (CSF) and accumulate in the retina. Aβ is known to cause tau hyperphosphorylation, leading to its buildup in various retinal layers. However, diseases like AD are now seen as mixed proteinopathies, with deposits of the prion protein (PrP) and α-synuclein found in affected brains and retinas. Glial cells, especially microglial cells, play a crucial role in these diseases, maintaining immunoproteostasis. Studies have shown similarities between retinal and brain microglia in terms of transcription factor expression and morphotypes. All these findings constitute a good start to achieving better comprehension of neurodegeneration in both the eye and the brain. New insights will be able to bring the scientific community closer to specific disease-modifying therapies.