Lacrimation Research Articles

Erratum to: Soluble B-cell maturation antigen in lacrimal fluid as a potential biomarker and mediator of keratopathy in multiple myeloma.

Erratum to: Soluble B-cell maturation antigen in lacrimal fluid as a potential biomarker and mediator of keratopathy in multiple myeloma.

Chronic dacryocystitis due to Mycobacterium abscessus.

Dacryocystitis, inflammation and infection of the lacrimal sac, is most commonly caused by infection from Staphylococcus and Streptococcus species. This report highlights a rare case of chronic dacryocystitis due to the atypical pathogen Mycobacterium abscessus. A 62-year-old woman presented with several months of left medial canthal pain, tenderness, and discharge. Exam demonstrated a left tender medial nodule, and imaging showed left lacrimal sac dilation and fluid collection consistent with dacryocystitis. She underwent external dacryocystorhinostomy with drainage and culture of the abscess, which was positive for M. abscessus. Her post-surgical treatment required an extended course of antibiotics, including omadacycline and azithromycin, with slow but progressive symptomatic improvement. This case is only the second reported case of dacryocystitis due to M. abscessus and suggests a role for culturing lacrimal sac abscesses intraoperatively due to the need for extended antibiotic therapy for atypical infections that may have high antibiotic resistance.

Tear levels of apoptotic, matrix-degrading and antioxidant biomarkers in patients with and without keratoconus: A cross sectional study

PurposeTo assess the tear levels of a set of apoptotic, matrix-degrading and antioxidant biomarkers, including Metalloproteinase 9 (MMP9), High Mobility Group Box 1 (HMGB1) and Superoxide Dismutase 3-Extracellular (SOD3). MethodsSandwich-ELISA commercial kits were used to test the expression of the three tear biomarkers in the lacrimal fluid of eligible participants. Linear logistic regression analysis was performed todetermine whether the set of tear biomarkers could be associated with clinically manifest keratoconus. ROC curve analysis using 10-fold cross-validation was performedto evaluate the prediction accuracy of the model. ResultsEighty-one participants aged 30–48 years old were enrolled in this study; 48 were patients with keratoconus and 33 were age-matched healthy subjects. The linear combination of the three tear biomarkers levels (AUC = 0.811; CI 95 %: 0.712–0.911) accurately indicated the existence of keratoconus; higher levels of MMP9 (Odd Ratio: 1.069; CI 95 %: 1.029–1.130) and HMGB1 (OR: 1.011; CI 95 %: 1.003–1.022) and lower levels of SOD3 (OR: 0.994; CI 95 %: 0.989–0.997) were significantly associated with a higher probability of keratoconus. ConclusionMultivariable analysis of the set of tear levels of MMP9, HMGB1 and SOD3 biomarkers confirmed a chronic state of inflammation in the ocular surface of patients with keratoconus.

The impact of cellulose nanocrystals on the properties of poly(2‐hydroxyethyl methacrylate)‐based contact lenses

AbstractContact lenses are widely used corrective devices for addressing vision impairments. In addition to their traditional role, these lenses are increasingly applied in personalized care, biosensing, and drug release, thus broadening their application as multifunctional devices. Nanoparticles are often used to introduce new functionalities to these materials. In this context, the role played by different nanoparticles requires attention to ensure that lens manufacture and patient comfort meet the desired criteria. This study investigates the properties of contact lenses prepared by incorporating cellulose nanocrystals into the poly(2‐hydroxyethyl methacrylate) matrix. Using photopolymerization reactions, polyHEMA‐based lenses and nanocomposites containing freeze‐dried and never‐dried nanoparticles were obtained. Fundamental properties of these lenses were evaluated to verify whether the nanoparticles could have a negative effect on the materials. Subsequently, the potential impact of these nanoparticles on the adsorption of model amino acids was investigated. Our findings reveal that the presence of cellulose nanocrystals modifies on lens thickness, light transmittance, mechanical properties, refractive index (RI), and the uptake of amino acids by the contact lenses. This could potentially affect patient comfort and modify the uptake and release of pharmaceutical ingredients by the material. Additionally, it could impact how these materials interact with biomolecules present in the lacrimal fluid.

Immune Responses in the Harderian Gland After Newcastle Disease Vaccination in Chickens with Maternal Antibodies.

Immune responses in the Harderian gland (HG) were characterized after Newcastle disease virus (NDV) LaSota ocular vaccination in antibody-naïve specific-pathogen-free (SPF) chickens and in chickens of commercial origin with NDV maternally derived antibodies (MDA). Ocular LaSota vaccination of 13-day-old white leghorn SPF chickens elicited serum antibody levels that consistently increased 15 days postvaccination, while the specific IgA response in lacrimal fluids was already detectable 10 days after vaccination. Eleven days postvaccination, the relative abundance of B cells, as well as T-helper cells (CD4+) and cytotoxic T cells (CD8+), in HGs was significantly increased, achieving maximum frequencies 16 days postvaccination. In a second experiment, chickens with MDA originating from NDV-vaccinated commercial white leghorn layer breeders, as well as white leghorn SPF chickens, were vaccinated with NDV LaSota. The LaSota virus successfully replicated in periocular tissues and in the trachea both in commercial and control SPF chickens after vaccination at 2 or 15 days of age (DOA). Vaccination at 2 DOA did not induce a serum NDV antibody response in chickens of commercial origin. In contrast, seroconversion was elicited in commercial chickens upon vaccination at 15 DOA, likely associated with waning of MDA. Unlike systemic IgG responses, vaccination at 2 or 15 DOA elicited strong specific IgA responses in lacrimal fluids in commercial chickens. The IgA response was highest 9 days after vaccination and showed a tendency to decline 15 days postvaccination. Commercial chickens vaccinated at 2 DOA showed increased B cells in HG 10 and 16 days postvaccination. The expansion of B cells in the HG in these chickens is consistent with increased IgA levels detected in lacrimal fluids. In contrast, control SPF chickens showed a more limited B-cell expansion in HG and lower IgA levels. Vaccination at 15 DOA also triggered a greater increase of B cells in HGs in commercial chickens than in control SPF chickens. The B-cell response was accompanied by T-helper (CD4+) cell expansion, occurring both in commercial and control SPF chickens. These cells expanded to a lesser extent when vaccination was performed at 2 DOA compared with vaccination at 15 DOA. CD8+ showed significant expansion irrespective of vaccination day and without differences detected between control SPF chickens and chickens with MDA. We conclude that NDV LaSota elicits vigorous humoral and cell immune responses in the HG. Furthermore, unlike the interference shown by MDA on vaccine-induced serum antibody responses, MDA do not interfere with the mucosal immune response of the HG.

Agreement between lacrimal fluid and serum for detecting urea nitrogen and creatinine in dogs.

To determine whether urea nitrogen and creatinine levels differ in lacrimal fluid (LF) and serum (SER) in nonazotemic (control) and azotemic dogs and whether there is an agreement between LF and SER. A prospective observational study was performed at the Auburn University Small Animal Teaching Hospital between May 2023 and March 2024. Forty control and 38 azotemic dogs were enrolled. Twenty microliters of LF per eye was collected with microcapillary tubes, and 3 mL of blood was drawn. Bland-Altman plot and intraclass correlation coefficient (ICC) were used to evaluate the agreement between LF and SER. There was good agreement between LF and SER levels of urea nitrogen in the control group (Bland-Altman plot mean bias of -0.8108 ± 2.407 mg/dL; ICC of 0.874 [95% CI, 0.773 to 0.934]) and the azotemic group (Bland-Altman plot mean bias of -9.681 ± 23.89 mg/dL; ICC of 0.82 [95% CI, 0.658 to 0.906]). There was poor agreement between LF and SER concentrations for creatinine in the control and azotemic groups, with only 26 dogs with creatinine detectable in LF. Lacrimal fluid and SER concentrations of urea nitrogen showed good agreement in both the control and azotemic groups, whereas poor agreement was found for creatinine in both groups. Measurement of urea nitrogen in LF may provide an alternative to blood for diagnosing uremia. However, additional research is necessary before substituting LF for SER.

The Role of Aquaporin 4 in Lacrimal Gland Ductal Fluid Secretion in Mice.

Earlier reports highlighted the predominant presence of aquaporin 4 (AQP4) in the duct cells of rabbit lacrimal glands (LGs). Whereas significant alterations in AQP4 mRNA levels have been observed in experimental dry eye and during pregnancy, the impact of AQP4 in LG ductal fluid production remains unclear. In our recent work, the role of AQP4 in LG ductal fluid secretion was investigated utilizing wild type (WT) and AQP4 knock out (KO) mice. Tear production was assessed in both WT and KO animals. Immunostaining was used to identify AQP4 protein. Duct segments were harvested from LGs of WT and KO mice. Fluid secretion and filtration permeability (Pf) were quantified using video-microscopy. Ductal tear production, elicited by a cell-permeable cAMP analogue (8-bromo cAMP), carbachol, vasoactive intestinal peptide (VIP), and phenylephrine (PHE), were assessed in both WT and KO ducts. A higher expression of AQP4 protein was noted in the duct cells from WT mice when compared to acinar cells. Pf did not show notable alterations between WT and AQP4 KO ducts. Carbachol elicited comparable secretory responses in ducts from both WT and KO animals. However, 8-bromo cAMP, VIP, and PHE stimulation resulted in decreased secretion in ducts from AQP4 KO LGs. Our findings underscore the functional relevance of AQP4 in the fluid production of mouse LG ducts. AQP4 seems to play different roles in fluid secretions elicited by different secretagogues. Specifically, cAMP-mediated, and adrenergic agonist-related secretions were reduced in AQP4 KO ducts.

Developing a quantitative method of mangiferin in rabbit lacrimal fluid as a tool for investigating pre-cornea drug residence

Mangiferin (MGF) has been evidenced to effectively treat infectious diseases caused by Herpes simplex virus, especially on the acyclovir-resistant strains. For ophthalmic disease treatment, prolonging drug retention in the eyes plays an essential role in effectively delivering drugs, which are prone to elimination by eye blinking and tear fluid secretion. The objective of this study was to develop a method for analysis of MGF in tear fluid that can be further utilised to evaluate the kinetics of precornea drug concentration. For sample collection, lacrimal tear fluid was absorbed into pre-weighed absorbing paper strips, which were then immediately weighed again right after sampling to calculate the sample mass. Subsequently, MGF was extracted from the paper strips using a mixture of methanol : acetic acid 0.6% (35:65, v/v). The extracted solution was finally injected into an HPLC system for MGF analysis (RP-column C18 - 4.6 x 250 mm, 5 μm was stabilised at 40oC; moblie phase methanol : acetic acid 0.6%; 35 : 65 (v/v) at a flow rate of 1.0 mL/min; autosampler, injection volume 10 µL; detection wavelength: 258 nm). The developed methodology was validated following the U.S. FDA and ICH M10 guidances for bioanalytical method validation, with respect to system suitability, linearity, recovery, accuracy and precision, dilution integrity and stability. The method was also successfully employed to determine MGF concentration in the tear fluid collected from rabbit eyes at one hour after instilling with MGF suspension. The methodology herein provides a practical tool to investigate kinetics of MGF in tear fluid that can be applied in ophthalmic drug development as well as drug quality evaluation activities.

Mucoadhesive, antioxidant, and lubricant catechol-functionalized poly(phosphobetaine) as biomaterial nanotherapeutics for treating ocular dryness.

Dry eye disease (DED) is associated with ocular hyperosmolarity and inflammation. The marketed topical eye drops for DED treatment often lack bioavailability and precorneal residence time. In this study, we investigated catechol-functionalized polyzwitterion p(MPC-co-DMA), composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and dopamine methacrylamide (DMA) monomers, as potential topical nanotherapeutics for DED. The copolymers were synthesized via random free-radical copolymerization, producing different proportions of catecholic functionalization. All as-prepared polymer compositions displayed good ocular biocompatibility. At a feeding ratio of 1:1, p(MPC1-co-DMA1) can facilitate a robust mucoadhesion via Michael addition and/or Schiff base reaction, thus prolonging ocular residence time after 4 days of topical instillation. The hydration lubrication of MPC and radical-scavenging DMA endow the nano-agent to ease tear-film hyperosmolarity and corneal inflammation. A single dose of p(MPC1-co-DMA1) (1mg/mL) after 4 days post-instillation can protect the cornea against reactive oxygen species, inhibiting cell apoptosis and the over-expression of pro-inflammatory factors (IL-6 and TNF-α). In clinical assessment, DED-induced rabbit eyes receiving p(MPC1-co-DMA1) could increase lacrimal fluid secretion by 5-fold higher than cyclosporine A. The catechol-functionalized polyzwitterion with enhanced lubricity, mucoadhesion, and anti-oxidation/anti-inflammation properties has shown high promise as a bioactive eye drop formulation for treating DED.

Current treatment options for dry eye syndrome in children

AIM: To analyze personalized therapy for dry eye syndrome (DES) in children, depending on the etiopathogenesis and severity of the disease.
 MATERIAL AND METHODS: In total, 187 children aged 3–17 years with DES were treated. Ophthalmic medicines registered in Russia from the group of local rehydrants replacing tear fluid and stabilizing tear film were used, and a comparative analysis of their effectiveness was carried out.
 RESULTS: An individual approach was implemented, and personalized therapy focused on the individual tolerability and effectiveness of medicines was developed. The principle of DES therapy is to replenish the lacrimal fluid deficiency and stabilize all layers of the tear film, considering the etiopathogenesis and severity of clinical symptoms. At this stage, the lipid layer of the tear film was normalized with the help of hypotonic oil-based preparations that can stabilize the lipid layer. All rehydrants of low, medium, and high viscosities contributed to the restoration of the water layer of the joint venture. The deficiency of the mucin layer of the tear film was compensated by hyaluronic acid and carboxymethylcellulose, which are part of the preparations that replace the tear film. The severity of DES associated with the intensity of the clinical changes in the conjunctiva and cornea was considered when designing the DES treatment regimen in children. In cases of mild and extremely severe severity, tear-replacement medicines of low viscosity showed the greatest therapeutic effectiveness. High-viscosity preparations and gels have been proven to be effective in moderate to severe DES. During the desquamation of the conjunctival and corneal epithelium, medicines with regenerating pharmacological action related to tissue repair simulators were included in the treatment regimen. Reparants included in the combined composition of tear-replacement medicines or monopreparations were used.
 CONCLUSION: The effectiveness of the DES treatment algorithm in children with various nosologies and features of etiopathogenesis was analyzed considering disease severity. The proposed schemes of personalized tear-replacement and reparative therapy make it possible to prevent a chronic disease course and occurrence of complications and preserve or restore visual acuity.

Detection of infectious SARS-CoV-2 in ocular samples is linked to viral load in the nasopharynx.

SARS-CoV-2 is known to infect respiratory tissue cells. However, less is known about infection of ocular tissue and potential infectivity of lacrimal fluid. With this study, we want to compare viral loads in eye and nasopharyngeal swabs and analyze these for infectious virus. Between May 2020 and April 2021 ocular and nasopharyngeal swabs were collected from 28 SARS-CoV-2 infected patients treated on the corona virus disease 2019 (COVID-19)-ward of the University Hospital of Innsbruck, Austria. Samples with PCR detectable SARS-CoV-2 were analyzed via whole genome sequencing and an attempt was made to isolate infectious virus. At the time point of sample collection, 22 individuals were still PCR positive in nasopharyngeal samples and in 6 of these patients one or both ocular samples were additionally positive. CT-values in eyes were generally higher compared to corresponding nasopharyngeal samples and we observed a tendency for lower CT-values, i.e. increased viral load, in nasopharyngeal swabs of individuals with at least one infected eye, compared to those where ocular samples were PCR negative. Ocular and nasopharyngeal sequences from the same patient were assigned to the same variant, either the D614G or the Alpha variant. Infectious virus was successfully isolated from 9 nasopharyngeal swabs, however only from one of the seven PCR positive ocular samples. We could detect SARS-CoV-2 in eyes of some of the infected patients albeit at lower levels compared to nasopharyngeal swabs. However, our results also indicate that lacrimal fluid might be infectious in patients with high viral load.

Dogs can detect an odor profile associated with Staphylococcus aureus biofilms in cultures and biological samples.

The study investigated the utilization of odor detection dogs to identify the odor profile of Staphylococcus aureus (S. aureus) biofilms in pure in vitro samples and in in vivo biosamples from animals and humans with S. aureus periprosthetic joint infection (PJI). Biofilms form when bacterial communities aggregate on orthopedic implants leading to recalcitrant infections that are difficult to treat. Identifying PJI biofilm infections is challenging, and traditional microbiological cultures may yield negative results even in the presence of clinical signs. Dogs were trained on pure in vitro S. aureus biofilms and tested on lacrimal fluid samples from an in vivo animal model (rabbits) and human patients with confirmed S. aureus PJI. The results demonstrated that dogs achieved a high degree of sensitivity and specificity in detecting the odor profile associated with S. aureus biofilms in rabbit samples. Preliminary results suggest that dogs can recognize S. aureus volatile organic compounds (VOCs) in human lacrimal fluid samples. Training odor detection dogs on in vitro S. aureus, may provide an alternative to obtaining clinical samples for training and mitigates biosecurity hazards. The findings hold promise for culture-independent diagnostics, enabling early disease detection, and improved antimicrobial stewardship. In conclusion, this research demonstrates that dogs trained on in vitro S. aureus samples can identify the consistent VOC profile of PJI S. aureus biofilm infections. The study opens avenues for further investigations into a retained VOC profile of S. aureus biofilm infection. These advancements could revolutionize infectious disease diagnosis and treatment, leading to better patient outcomes and addressing the global challenge of antimicrobial resistance.

Ocular bioanalysis of moxifloxacin and ketorolac tromethamine in rabbit lacrimal matrix using liquid chromatography-tandem mass spectrometry.

Aim: The fixed-dose combination of moxifloxacin (MOXI) and ketorolac tromethamine (KTR) is widely used for the treatment of bacterial keratitis. Thus, a new LC-MS/MS method was developed to determine MOXI and KTR in lacrimal fluid. Methods: Bioanalysis was performed using aShimadzu 8050 LC-MS/MS in electrospray ionization-positive mode and the method was validated per US FDA guidelines. Isocratic separation wasperformed with aWaters Symmetry C18 column using methanol and 0.1% formic acid containing deionized water (85:15, v/v). Results & conclusion: An easy, quickand selective method was established and applied to assess the ocular pharmacokinetic profile of a commercially available formulation containing MOXI and KTR. Based on thepharmacokinetic data, this work describes pharmacokinetics-based dosage regimen calculations and their clinical significance.

Peculiarities of local immunity in dry eye disease on the background of hormonal dysfunction.

Aim: to determine the state of local immunity in DED on the background of hormonal dysfunction. Materials and Methods: Of 32 women, 17 patients with diagnosed SM and 15 women of the control group were examined. The Ocular Surface Disease Index and the state of local immunity were defined by determining Ig As in lacrimal fluid (LF) by radial immunodiffusion in Mancini agar. Results: During the OSDI questionnaire, a mild degree of DED was detected in 21 (65.6%) women, and an average degree was observed in 11 (34.4%) patients with SM. On average, OSDI was 34.54 ±2.01. As a result of studies of the state of local immunity in patients with SM, a tendency to increase Ig As was noted, compared with the control group. An increase in Ig As in the lacrimal fluid in patients with SM to 0.34 ±0.09 g/l was found, compared with the control group (0.24 ±0.03 g/l). Conclusions: Using the OSDI questionnaire, the presence of DED was detected in women with SM, mainly mild and moderate degree. The obtained results of the state of local immunity indicate in favor of a nonspecific inflammatory process, accompanied by a decrease in local immune protection and leading to further changes in the ocular surface.

Tear biomarkers.

An extensive exploration of lacrimal fluid molecular biomarkers in understanding and diagnosing a spectrum of ocular and systemic diseases is presented. The chapter provides an overview of lacrimal fluid composition, elucidating the roles of proteins, lipids, metabolites, and nucleic acids within the tear film. Pooled versus single-tear analysis is discussed to underline the benefits and challenges associated with both approaches, offering insights into optimal strategies for tear sample analysis. Subsequently, an in-depth analysis of tear collection methods is presented, with a focus on Schirmer's test strips and microcapillary tubes methods. Alternative tear collection techniques are also explored, shedding light on their applicability and advantages. Variability factors, including age, sex, and diurnal fluctuations, are examined in the context of their impact on tear biomarker analysis. The main body of the chapter is dedicated to discussing specific biomarkers associated with ocular discomfort and a wide array of ocular diseases. From dry eye disease and thyroid-associated ophthalmopathy to keratoconus, age-related macular degeneration, diabetic retinopathy, and glaucoma, the intricate relationship between molecular biomarkers and these conditions is thoroughly dissected. Expanding beyond ocular pathologies, the chapter explores the applicability of tear biomarkers in diagnosing systemic diseases such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, Parkinson's disease, and cancer. This broader perspective underscores the potential of lacrimal fluid analysis in offering non-invasive diagnostic tools for conditions with far-reaching implications.

Copolymerized Polymers Based on Cyclodextrins and Cationic Groups Enhance Therapeutic Effect of Rebamipide in the N-Acetylcysteine-Treated Dry Eye Model.

We aimed to prepare a β-cyclodextrin (β-CD) polymer using radical polymerization with co-monomers, 6-deoxy-6-(2-methacryloyloxyethylsuccinamide)-β-cyclodextrin (CD-MSAm) and N,N,N-trimethyl-N-(2-hydroxy-3-metacryloyloxopropyl)-ammonium chloride (QA) to design cyclodextrins suitable for use in ophthalmology. In addition, we evaluated their solubility and inclusion properties with rebamipide (REB), a poorly soluble drug, and investigated the usefulness of the β-CD polymer and REB (REB@CDQA) combination in treating dry eye. The β-CD polymer (CD-MSAm-co-QA, CDQA) based on CD-MSAm/QA was prepared via radical polymerization, and the usefulness of REB@CDQA in treating dry eye was evaluated using a rabbit treated with N-acetylcysteine (dry eye model). The solubility of the CDQA powder was higher than that of the β-CD powder, and 80 nm colloids were observed in the CDQA solution. No corneal toxicity was observed in human corneal epithelial cells or rat corneas treated with 0.2% CDQA solution. The levels of REB dissolved in the CDQA solution were higher than those of the β-CD solution. Moreover, the application of the CDQA solution enhanced REB retention in the cornea and attenuated the transcorneal penetration of REB. In addition, instillation of REB@CDQA enhanced the volume of the lacrimal fluid and normalized the reduced mucin levels in the dry eye model. The extent of tear film breakup was attenuated by REB@CDQA instillation. The CDQA solution enhanced the solubility of REB, and the combination of CDQA and REB enhanced the drug content in the corneal tissue. Moreover, the therapeutic effect on dry eye was higher than that of REB suspensions without CDQA.

Dry Eye Syndrome in Refractive Patients. Literature Review

Dry eye syndrome is a multifactorial disease of the ocular surface, which is based on the development of hyperosmolarity, inflammation and sensorineural disorders in the imbalance of the structural components of the tear film. The main complaints of refractive patients after keratorefractive surgery are a feeling of dryness in the eyes, a foreign body, redness, blurring of the image, which is due to the clinical manifestations of post-refractive dry eye syndrome. There are factors that contribute to the development of postrefractive dry eye syndrome, such as: neurotrophic epitheliopathy, postoperative inflammation, damage to goblet cells, toxic corneal epitheliopathy caused by preservatives contained in eye drops, leading to inadequate restoration of the tear film. In clinical practice, to assess the stability of the tear film, a method is used to determine the tear film rupture time using invasive and non-invasive methods. Invasive methods include: staining of the ocular surface with a solution of fluorescein during the Norn test. To date, laboratory diagnostics expands the understanding of the pathogenesis, etiology and mechanisms underlying the xerosis of the ocular surface at the molecular level, and also facilitates the diagnosis and prognosis of dry eye syndrome. Laboratory methods of the ocular surface include the study of biomarkers of lacrimal fluid, conducting impression cytology with an assessment of the condition of goblet cells. In this regard, it is necessary to have a deep understanding of the main etiopathogenetic links of dry eye syndrome, a wide range of diagnostics of the condition of the ocular surface before and after the surgical stage of patient management, which will determine the success of keratorefractive surgery and a stable course of the postoperative period.

Reduced Levels of Lacrimal Glial Cell Line-Derived Neurotrophic Factor (GDNF) in Patients with Focal Epilepsy and Focal Epilepsy with Comorbid Depression: A Biomarker Candidate.

Our previous studies showed that in patients with brain diseases, neurotrophic factors in lacrimal fluid (LF) may change more prominently than in blood serum (BS). Since glial cell line-derived neurotrophic factor (GDNF) is involved in the control of neuronal networks in an epileptic brain, we aimed to assess the GDNF levels in LF and BS as well as the BDNF and the hypothalamic-pituitary-adrenocortical and inflammation indices in BS of patients with focal epilepsy (FE) and epilepsy and comorbid depression (FE + MDD) and to compare them with those of patients with major depressive disorder (MDD) and healthy controls (HC). GDNF levels in BS were similar in patients and HC and higher in FE taking valproates. GDNF levels in LF were significantly lower in all patient groups compared to controls, and independent of drugs used. GDNF concentrations in LF and BS positively correlated in HC, but not in patient groups. BDNF level was lower in BS of patients compared with HC and higher in FE + MDD taking valproates. A reduction in the GDNF level in LF might be an important biomarker of FE. Logistic regression models demonstrated that the probability of FE can be evaluated using GDNF in LF and BDNF in BS; that of MDD using GDNF in LF and cortisol and TNF-α in BS; and that of epilepsy with MDD using GDNF in LF and TNF-α and BDNF in BS.

Polymorphism of proinflammatory inerleukin genes in primary open-angle glaucoma

Glaucoma is a degenerative disease of the optic nerve, accompanied by the death of retinal ganglion cells (RGCs) and loss of vision. An important role in the pathogenesis of glaucoma is ascribed to activated microglia, which produce pro-inflammatory interleukins and initiate GCS apoptosis. It has been established that single nucleotide polymorphisms of interleukin genes modify the development of neuroinflammation, but their effect on the risk of developing glaucoma is not yet fully established. Our aim was to determine the pathogenetic role of gene polymorphisms in TNFα and IL1β in the development of primary open-angle glaucoma.We have observed 56 patients of Russian nationality from the South of Russia with primary open-angle glaucoma (POAG), 28 patients with stage I, 16 with stage II, 12 with stage III POAG. The single nucleotide polymorphisms TNFα 308G>A (rs1800629) and IL1β -31 Т>С (rs1143627) were studied by restriction fragment analysis of PCR products. The level of pro-inflammatory cytokines (TNFα and IL1β) in the lacrimal fluid of patients with POAG was evaluated by enzyme-linked immunosorbent assay (Vector-Best test system). To perform optical coherence tomography by analysing the thickness of retinal nerve fiber layer (RNFL) with volume and area of the neuroretinal rim using Torson 3D OST 1000 apparatus.Results: in patients with POAG, we have found more common incidence of TNFα 308A (OR = 5.21, p = 0.001), and IL1β-31 T alleles (OR = 1.99, p = 0.04). An increased risk of developing POAG was found in carriers of genotypes 308A/A (OR = 6.30, p = 0.049), 308G/A (OR = 3.60, p = 0.049) and -31T/T (OR = 2.67, p = 0.04). The highest levels of TNFα were determined in the 308A/A group (190 (153.0-220.0) pg/mL), IL1β were in the group (-31) T/T – 6.50 (4.10-7.00) pg/mL. A decreased thickness of the retinal nerve fibers was observed in the patients with TNFα G308A genotype (59.5; 40.0 to 78.0 µm, p = 0.03), and in TNFα A308A carriers (79.0; 65.0 to 80.0 µm, p = 0.001).The TNFα 308 G/A (rs1800629), along with IL1β, -31Т/C (rs1143627) cytokine gene polymorphisms are associated with development of primary open-angle glaucoma. TNFα 308A, IL1β -31T alleles, as well as the 308G/A, 308A/A and -31T/T genotypes seem to be the risk factors for POAG in Russian population. High content of TNFα in the lacrimal fluid was found in the carriers of 308A/A genotype and -31T/T IL1β genotype. The lowest thickness of the retinal nerve fiber layer was observed in the carriers of tTNFα A308A and TNFα G308A genotypes.

Methods for monitoring the effectiveness of direct-acting anticoagulants in diabetic retinopathy

Anticoagulants are the basis for the treatment of various diseases that induces the development of arterial and venous thrombosis. One such disease is diabetic retinopathy. However, no consensus has been reached regarding the best way to control the effectiveness of these drugs. Thus, active search is ongoing for specific biomarkers that reflect treatment quality. To this end, this study analyzed scientific papers that presented the results of various laboratory diagnostics aimed at examining the use of anticoagulants in the treatment of diabetic retinopathy.
 PubMed and eLIBRARY.RU were searched for legible studies. The review analyzed studies that describe the main groups of anticoagulants and methods of laboratory control of their use and published in the past 30 years. Review articles, results of experimental studies, monographs, study guides, and dissertations were analyzed.
 Anticoagulants are divided into direct and indirect. In modern clinical practice, direct ones are mainly used. To control their effectiveness, traditional methods for determining the coagulogram are mainly used; however, increasingly more often, the authors resort to a more detailed study of the rheological properties of the blood, such as determination of anti-X activity, platelet aggregation using inductors, and activity of clotting factors. In addition, determining their effect on the concentration of pro-inflammatory cytokines and growth factors in the blood serum and lacrimal fluid in diabetic retinopathy remains promising.
 However, no consensus has been established on which research methods most accurately reflect the effect of anticoagulants on the hemostatic system and indicators of inflammatory activity in various diseases, particularly in diabetic retinopathy. Therefore, a detailed analysis of what laboratory parameters can change under the influence of these drugs is necessary.