The Pathomechanism, Antioxidant Biomarkers, and Treatment of Oxidative Stress-Related Eye Diseases

Protective effects of different exercise modalities on oxidative stress in animal models of high intraocular pressure and diabetes

High intraocular pressure (HIOP) and high glucose levels are associated with oxidative stress. Although physical exercise protects against oxidative damage, its specific impact on eye health remains unclear. Thus, this study aimed to assess the impact of physical exercise on the oxidative status of whole eyes in male Swiss mice subjected to HIOP model and cafeteria diet (CD). In experiment one, mice were divided into sedentary, aerobic, and strength (four-week physical exercise) groups and subjected to an HIOP/ischemia model. In experiment two, mice were submitted to CD and voluntary physical exercise for 18 weeks, according to the following groups: sedentary control, sedentary CD, exercise control, and exercise CD. Experiment one revealed elevated 2',7'-dichlorodihydrofluorescein (DCFH) levels in aerobic group, which decreased in all groups after ischemia. Nitrite levels were decreased on strength than in sedentary group. The superoxide dismutase (SOD) activity did not change in all treatments. Although catalase (CAT) activity increased in aerobic and strength groups, and after ischemia in all groups. In experiment two, the sedentary CD group presented higher body weight than the other groups. DCFH levels were increased in the exercise control and reduced in the exercise CD compared with the other groups. CAT activity and sulfhydryl groups were decreased, while protein carbonylation was increased in the sedentary CD group compared with the other groups. Thus, these results suggested that physical exercise promoted antioxidant effects on eyes exposed to an HIOP model and CD.

Emerging treatment strategies in dry eye disease: Potential of blood-derived approaches and natural plant-based products

Dry eye disease (DED) is a common ocular condition characterized by chronic inflammation and tear film disruption. It affects millions of people worldwide, causing significant eye discomfort and vision disturbances. Despite its prevalence, DED remains a complex condition that is not yet fully understood. It can arise from various ocular pathologies, including endocrinological disorders such as diabetes and Graves' orbitopathy. Natural products, including plant- and blood-based therapies, have shown promise in alleviating DED symptoms and may represent effective therapeutic approaches. In this study, we review recent research on natural product treatments for DED, focusing on blood-derived therapies (e.g., autologous serum, albumin serum, and allogeneic serum) and plant-based compounds such as omega-3 fatty acids (O3FA), omega-6 fatty acids (O6FA), antioxidants, polyphenols, and flavonoids. Additionally, we examine the efficacy, mechanisms of action, and delivery systems of these treatments, highlighting the potential of blood-derived therapies, polyphenols, and flavonoids to improve or treat DED through multiple mechanisms. However, the use of these natural products as instilled drugs is limited by challenges such as solubility, stability, and biological barriers. Finally, we discuss drug delivery systems and structural modifications designed to enhance the therapeutic effects of these treatments, emphasizing their potential in managing DED.

SMP30 Alleviates Oxidative Stress and Regulates Ca2+-ATPase Activity in UVR-B-Induced Cataracts in Rats

PURPOSE

Oxidative stress, ultraviolet radiation, and calcium imbalance are key components in the onset and advancement of cataract, which continue to be the leading cause of blindness globally. An important newly discovered aging maker, Senescence marker protein 30 (SMP30) regulates calcium and participates in mitigating oxidative stress damage. Here, we examined the beneficial role of SMP30 in protecting against ultraviolet radiation type B (UVR-B)-induced cataract in rats.

METHODS

Wistar rats (2 months) were arbitrarily assigned into 4 groups of 10 rats. These groups included the Control group, UVR-B group, adeno-associated virus 2 vectors negative control (AAV2-NC) group, and adeno-associated virus 2-mediated overexpression of SMP30 (AAV2-SMP30) group. The control group received Phosphate-buffered saline (PBS) via injection, while the AAV2-NC group and AAV-SMP30 group were separately injected with AAV2-NC and AAV2-SMP30 vectors. In addition to the control group, the remaining three experimental groups were subjected to ultraviolet light exposure 4 weeks post-injection. The lens opacity was examined by stereoscopic microscope, and the lenses were separated to measure oxidative damage parameters particularly superoxide dismutase (SOD), glutathione peroxidase (GPX), and Ca2+-ATPase activity. The localization and expression of SMP30 and Ca2+-ATPase in the lenses were determined using immunohistochemistry and RT-qPCR.

RESULTS

After UVR-B irradiation, the AAV2-SMP30 group exhibited a substantial decrease in lens opacity compared to the UVR-B group. The results revealed a notable downregulation of SMP30 expression and the activities of SOD, GPX, and Ca2+-ATPase of rat lens following exposure to UVR-B radiation. However, SMP30 overexpression partially reversed these effects. In vivo experiments demonstrated SMP30 overexpression attenuated the UVR-B-induced decline in SOD, GPX, and Ca2+-ATPase activities.

CONCLUSION

This study demonstrates that SMP30 has the potential to reduce lens opacity caused by UVR-B by increasing antioxidant stress and regulating Ca2+-ATPase activity. SMP30 might be a cutting-edge target for the treatment of cataracts.

Cysteinyl Leukotriene Receptor Antagonism by Montelukast to Treat Visual Deficits

Montelukast, a Food and Drug Administration-approved drug for asthma and allergic rhinitis modulates leukotriene (LT) receptors and serves as a critical anti-inflammatory agent. Recent research suggests that the LT signaling pathway targeted by montelukast has broader implications for diseases such as fibrosis, cardiovascular diseases, cancer, cerebrovascular disease, and immune defense. This expanded understanding highlights montelukast's potential for repurposing in conditions involving aberrant stress mechanisms, including ocular diseases marked by inflammation, oxidative stress, ER stress, and apoptosis, among several others. This review delves into montelukast's therapeutic mechanisms across various diseases, draws parallels to ocular conditions, and examines clinical trials and associated adverse effects to underscore the unmet need for cysteinyl LT receptor antagonism by montelukast as an effective therapy for visual deficits.

Ferroptosis is involved in the damage of ocular lens under long-term PM2.5 exposure in rat models and humans

Epidemiological studies show a positive association between air pollution and age-related cataracts, but the pathogenic mechanism remains unclear. This study first demonstrates that fine particulate matter (PM2.5) induces ferroptosis in the lens, leading to morphological and functional disorders, through human, animal, and cellular samples. In 3-week PM2.5-exposed rat models (10 µl 1 mg/ml PM2.5 suspension per eye, 4 times a day), we find that many vacuoles form in the lens equatorial region by analysis of haematoxylin and eosin staining after PM2.5 exposure. Using iron and glutathione (GSH) assay kits, we found increased Fe2+ contents and decreased GSH levels in PM2.5-exposed rats' lenses. Additionally, the lipid peroxide 4-hydroxynonenal (4-HNE) was also found to be elevated with immunoblot, suggesting ferroptosis is involved. Ferroptosis was also observed in human lens epithelial cells treated with 25, 50, and 100 µg/ml PM2.5 suspension for 24 h, accompanied by decreased cell viability and migration. Furthermore, we collect about 60 human lens anterior capsule (HLAC) samples for RNA-seq. The results show that compared to HLACs from areas with PM2.5 concentration ≤30 μg/m³, ferroptosis-related genes expression of those from areas with PM2.5 concentration ≥35 μg/m³ are significantly altered, such as glutathione peroxidase 4 and STEAP family member 3. Also, human lens in areas with high PM2.5 concentrations showed elevated levels of transferrin receptor and 4-HNE with immunoblot, and down-regulated expression of connexin 43 (Cx43) through immunofluorescent. These results demonstrate that ferroptosis plays a key role in PM2.5-induced cataractogenesis.

Associations Between Life's Essential 8 and Major Ocular Diseases in the American Middle-Aged and Elderly Population

PURPOSE

To explore the correlation between cardiovascular health (CVH) and ocular diseases, given their shared risk factors and biological mechanisms, this study utilizes the newly updated Life's Essential 8 (LE8) algorithm.

DESIGN

A cross-sectional study.

METHODS

This analysis, conducted from February 15 to April 1, 2024, in Changchun, includes data from 4146 participants aged 40 and above, drawn from the National Health and Nutrition Examination Survey database (2005-2008). It covers information on visual health status, dietary habits through interviews, and professional ophthalmological examinations. Participants' CVH status was assessed using the LE8 algorithm, and relationships with major ocular diseases such as retinopathy, cataracts, diabetic retinopathy, glaucoma, and age-related macular degeneration were explored through weighted logistic regression analysis, restricted cubic splines, stratified analysis, and sensitivity analysis.

RESULTS

After multivariable adjustment, lower LE8 scores showed a significant positive relationship with any ocular disease (odds ratio [OR]: 2.03, 95% confidence interval [CI]: 1.39-2.96, P = .001), any objectively determined ocular disease (OR: 2.24, 95% CI: 1.48-3.38, P < .001), retinopathy (OR: 2.88, 95% CI: 1.89-4.41, P < .001), diabetic retinopathy (OR: 10.23, 95% CI: 3.11-33.61, P < .001), and glaucoma (OR: 2.76, 95% CI: 1.47-5.21, P = .003), with all trends significant (all P < .01). Additionally, lower scores in the behavioral subdomain were significantly correlated with an elevated risk of cataracts (OR: 1.45, 95% CI: 1.03-2.04). Subgroup analyses revealed more pronounced negative correlations between LE8 and retinopathy among females and those suffering from chronic kidney disease.

CONCLUSIONS

A low CVH score was linked to an increased likelihood of ocular diseases in a US-populated-based study. This correlation supports the potential benefits of enhancing cardiovascular wellness to mitigate the development of ocular conditions.

Identification and validation of oxidative stress-related genes in primary open-angle glaucoma by weighted gene co-expression network analysis and machine learning

Primary open-angle glaucoma (POAG) is a common ocular disease, and there is currently no effective treatment for POAG therapy. Thus, identifying some effective diagnostic markers is beneficial to the treatment of patients. The expression profile was obtained from Gene Expression Omnibus (GEO) database. The functional enrichment was analyzed using Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and gene set enrichment analysis. Co-expressed genes were identified using weighted gene co-expression network analysis (WGCNA). Hub genes were screened through Lasso regression, support vector machine-recursive feature elimination (SVM-RFE) and Random Forest, and receiver operating characteristic curve was used to assess diagnostic value. Immune cell infiltration was calculated using IOBR package. The regulatory network was constructed through STRING, miRactDB and Cytoscape. The oncoPredict package was employed to predict the candidate chemotherapy agents. According to GSE27276 database, 541 differentially expressed genes were identified. Five oxidative stress-related genes with high area under the curve value, namely HBB, MAOA, ACOX2, ALDH7A1 and TYMP, were determined using WGCNA and machine learning. Infiltration level of NK cells, CD4 T cells and dendritic cells were significantly increased in POAG group compared with normal group, while CD8 T cells and Tregs cells were significantly decreased. HBB was closely related to most immune cells. Hub genes were all targeted by 16 miRNAs. Drug sensitivity analysis exhibited that some drugs were more sensitivity for POAG, such as Acetalax_1804, Ibrutinib_1799 and OSI_027_1594. We identified 5 oxidative stress-related genes with high diagnostic value for POAG.

Ambient air pollution exposure and incidence of cataract surgery: The prospective 3City-Alienor study

PURPOSE

Cataract, the leading cause of blindness worldwide, is a multifactorial disease involving oxidative stress mechanisms. The aim of our study was to investigate the relationship between air pollution exposure and the incidence of cataract surgery.

METHODS

The 3C-Alienor study is a population-based cohort of residents of Bordeaux, France, aged 65 years or more, recruited in 1999-2000 and followed every 2-3 years until 2017. Cataract surgery was self-reported and checked at slit-lamp by trained professionals. Average air pollution exposure (particulate matter ≤2.5 μm (PM2.5), black carbon (BC), nitrogen dioxide (NO2)) in the 10 years preceding baseline was estimated at the participants' geocoded residential address, using temporally adjusted land use regression. Associations of 10-year average air pollution exposure with incidence of cataract were estimated using Cox proportional hazard models adjusted for confounders.

RESULTS

The study included 829 subjects without cataract surgery prior to inclusion; the mean age at inclusion was 72.6 years (standard deviation (SD): 4.2) and 61% were women. The median (Interquartile-range (IQR)) follow-up duration was 14.1 (6.4) years during which 507 participants underwent cataract surgery. Exposure to a concentration ≥40 μg/m3 of NO2 (the current regulatory limit value in Europe) was associated with incident cataract surgery (HR = 1.46, CI (1.16, 1.84), p = 0.001). No statistically significant association was found with PM2.5 and BC.

CONCLUSION

Long-term exposure to a NO2 concentration ≥ 40 μg/m3 was associated with an increased incidence of cataract surgery. Complying with current European air pollution standards could reduce cataract surgery costs and improve population quality of life.

Study of the Pharmacodynamic Material Basis and Mechanisms of the Action of Fubai Chrysanthemum in Relieving Visual Fatigue

Fubai chrysanthemum is a kind of traditional Chinese medicine, which can be used as a common food, and is commonly used to improve and relieve visual fatigue. However, its pharmacodynamic material basis and action mechanisms in relieving visual fatigue have not been systematically studied. In this article, 11 absorbed ingredients from Fubai chrysanthemum were detected in rat plasma. Then, the target network pharmacology and KEGG pathway analysis were performed. It was found that Fubai chrysanthemum could inhibit various apoptotic cells and reduce oxidative damage of eyes by regulating the apoptosis pathway, thus alleviating visual fatigue. Further in vitro experiments showed that Fubai chrysanthemum could effectively protect against oxidation damage of adult retinal pigment epithelial cells (ARPE-19), retinal ganglion cells (RGC-5), and lens. The results of cell experiments showed that Fubai chrysanthemum could increase the cell activity, GSH content, and SOD content of ARPE-19 and RGC-5 after oxidative injury, while decreasing the IL-18 content. Similarly, in the study of lens transparency, we found that Fubai chrysanthemum could effectively alleviate the oxidative damage degree of the lens, and significantly increase the content of CAT, GSH, and SOD. The above results suggested that Fubai chrysanthemum could play an important role in alleviating visual fatigue through regulating cell apoptosis and antioxidative damage.

Molecular docking analysis and in vivo assessment of zinc oxide nanoparticle toxicity in zebrafish larvae

The zinc oxide nanoparticles (ZnO-NPs) being widely employed in several industries and consumer products, are raising concerns about their safety on aquatic biota and human health. This study aims to investigate the possible toxicological effects of ZnO-NPs through a combined in vivo and in silico approach. Zebrafish embryos were exposed to several ZnO-NPs concentrations and morphological alterations and lipid peroxidation (MDA) were investigated. Furthermore, molecular docking simulations were applied to study the intermolecular interactions of ZnO-NPs against critical embryonic proteins namely zebrafish hatching enzyme1 (ZHE1) as well as the superoxide dismutase (SOD1). Treatment with ZnO-NPs resulted in an increase in MDA concentration and a decrease in antioxidant enzyme levels. Besides a significant decrease in mRNA expression of key enzymes of ROS detoxification genes, a modulation of inflammatory genes with a low downregulation of tnf-α, and an upregulation of il-1β were observed. Docking study suggests that the delayed hatching and increased cellular oxidative stress in zebrafish embryos may occur through a synergistic mechanism based on the ZnO-NP-dependent inhibition of ZHE1 and SOD1 enzymes. The integration of in vivo assessments with in silico computational modeling provided a more comprehensive evaluation of potential physiological risks in zebrafish embryos associated with nanomaterial exposure.

Moringa oleifera hydroalcoholic leaf extracts mitigate valproate-induced oxidative status in the extraorbital lacrimal gland in a rat model

Dysfunction of the extraorbital lacrimal gland (ELG) can lead to loss of vision due to damage to the epithelium of cornea. The broad-spectrum anti-epileptic drug sodium valproate (SV) has numerous side effects. Moringa oleifera (M.oleifera) is widely used as a food and in folk medicine. The effects of orally administered SV and M. oleifera hydroalcoholic leaf extract on rat ELG were investigated in this study by analysing both antioxidant and oxidant parameters. Additionally, boron level and tissue factor (TF) activity were determined. Protein changes were detected by sodium dodecyl sulfate gel electrophoresis (SDS-PAGE). Significantly lower values of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and total antioxidant status (TAS) were observed in the SV group compared to the control group. Treatment with Moringa extract significantly increased SOD, CAT and TAS values in the Moringa given SV group (SVM). While no significant differences were observed between the sialic acid values of the groups, lipid peroxidation (LPO), nitric oxide (NO) and total oxidant status (TOS) values were significantly elevated in the SV group compared to the control group. Due to the effect of Moringa extract, LPO, NO and TOS levels were significantly decreased in the SVM group compared to the SV group. TF activity was not meaningfully altered between groups. Compared to control rats, oxidative stress index (OSI) level significantly increased, whereas the boron level decreased in the SV group. Moringa extract treatment noticeably reduced OSI in the SVM group. According to SDS-PAGE, decreases in the density of protein bands with molecular weights of 51, 83, and 90 kDa were observed in SV given rats compared to the other groups. These decreases were reversed by the administration of Moringa extract. Moringa extract has shown protective properties arising from antioxidant potential, especially with its very low OSI value. Individuals undergoing SV treatment and having ELG complications might consider using Moringa extract to mitigate valproate induced damage.

Tissue engineering strategies for ocular regeneration; from bench to the bedside

Millions globally suffer from visual impairment, complicating the management of eye diseases due to various ocular barriers. The eye's complex structure and the limitations of existing treatments have spurred interest in tissue engineering (TE) as a solution. This approach offers new functionalities and improves therapeutic outcomes over traditional drug delivery methods, creating opportunities for treating various eye disorders, from corneal injuries to retinal degeneration. In our review of recent articles concerning the use of scaffolds for eye repair, we categorized scaffolds employed in eye TE from recent studies into four types based on tissue characteristics: natural, synthetic, biohybrid, and decellularized tissue. Additionally, we gathered data on the cell types and animal models associated with each scaffold. This allowed us to gather valuable insights into the benefits and drawbacks of each material. Our research elucidates that, in comparison to conventional treatment modalities, scaffolds in TE emulate the extracellular matrix (ECM) of the eye and facilitate cell proliferation and tissue regeneration. These scaffolds can be precisely tailored to incorporate growth factors that augment the healing process while also providing considerable advantages such as bacterial inhibition, biocompatibility, and enhanced durability. However, they also have drawbacks, such as potential immune responses, poor tissue integration, complex and costly manufacturing, and inconsistent degradation rates that can affect their effectiveness. In this review, we provide an overview of the present condition of eye regenerative treatments, assess notable preclinical and clinical research endeavors, contemplate the obstacles encountered, and speculate on potential advancements in the upcoming decade.

Selected Trace Elements and Their Impact on Redox Homeostasis in Eye Health

Oxidative stress plays a crucial role in the pathogenesis of various ocular degenerative diseases, leading to structural and functional changes in eye tissues. This imbalance between reactive oxygen species (ROS) and antioxidants significantly contributes to conditions such as age-related macular degeneration, diabetic retinopathy, cataracts, and glaucoma. Both enzymatic and nonenzymatic antioxidants are vital for maintaining ocular health by neutralizing ROS and restoring cellular redox balance. Essential trace elements, including iron, zinc, copper, and selenium, are fundamental for the proper functioning of these antioxidant systems. Iron is indispensable for enzymatic activity and cellular energy production, zinc supports numerous proteins involved in visual functions and antioxidant defense, copper is essential for various enzymatic reactions preventing oxidative stress, and selenium is critical for the activity of antioxidant enzymes such as glutathione peroxidase (GPX) and thioredoxin reductase (TrxR). This review summarizes current research on the complex interactions between oxidative stress and trace elements in ocular diseases, highlighting the therapeutic potential of antioxidant supplementation to mitigate oxidative damage and improve eye health. By integrating insights from studies on oxidative stress, trace elements, and eye physiology, this article underscores new diagnostic and therapeutic strategies that could lead to more effective prevention and treatment of ocular diseases, aiming to enhance clinical outcomes and guide future research in optimizing therapeutic strategies for eye health.

Oxidative Stress in Cataract Formation: Is There a Treatment Approach on the Horizon?

Cataracts, a leading cause of blindness worldwide, are closely linked to oxidative stress-induced damage to lens epithelial cells (LECs). Key factors contributing to cataract formation include aging, arterial hypertension, and diabetes mellitus. Given the high global prevalence of cataracts, the burden of cataract-related visual impairment is substantial, highlighting the need for pharmacological strategies to supplement surgical interventions. Understanding the molecular pathways involved in oxidative stress during cataract development may offer valuable insights for designing novel therapeutic approaches. This review explores the role of oxidative stress in cataract formation, focusing on critical mechanisms, such as mitochondrial dysfunction, endoplasmic reticulum stress, loss of gap junctions, and various cell death pathways in LECs. Additionally, we discuss emerging therapeutic strategies and potential targeting options, including antioxidant-based treatments.

Molecular Insights on Coffee Components as Chemical Antioxidants

Coffee is not only a delicious beverage but also an important dietary source of natural antioxidants. We live in a world where it is impossible to avoid pollution, stress, food additives, radiation, and other sources of oxidants that eventually lead to severe health disorders. Fortunately, there are chemicals in our diet that counteract the hazards posed by the reactive species that trigger oxidative stress. They are usually referred to as antioxidants; some of them can be versatile compounds that exert such a role in many ways. This review summarizes, from a chemical point of view, the antioxidant effects of relevant molecules found in coffee. Their mechanisms of action, trends in activity, and the influence of media and pH in aqueous solutions, are analyzed. Structure-activity relationships are discussed, and the protective roles of these compounds are examined. A particular section is devoted to derivatives of some coffee components, and another one to their bioactivity. The data used in the analysis come from theoretical and computational protocols, which have been proven to be very useful in this context. Hopefully, the information provided here will pro-mote further investigations into the amazing chemistry contained in our morning coffee cup.   Resumen. El café no solo es una bebida deliciosa, sino también una importante fuente dietética de antioxidantes naturales. Vivimos en un mundo donde es imposible evitar la contaminación, el estrés, los aditivos alimentarios, la radiación y otras fuentes de oxidantes que eventualmente conducen a trastornos de salud graves. Afortunadamente, existen sustancias químicas en nuestra dieta que contrarrestan los peligros planteados por las especies reactivas que desencadenan el estrés oxidativo. Por lo general, se les denomina antioxidantes; algunos de ellos pueden ser compuestos versátiles que ejercen dicho papel de muchas maneras. Este artículo de revisión resume, desde un punto de vista químico, los efectos antioxidantes de moléculas relevantes encontradas en el café. Se analizan sus mecanismos de acción, tendencias en la actividad y la influencia del medio y el pH en soluciones acuosas. Se discuten las relaciones estructura-actividad, y se examinan los roles protectores de estos compuestos. Se dedica una sección particular a los derivados de algunos componentes del café, y otra a su bioactividad. Los datos utilizados en el análisis provienen de protocolos teóricos y computacionales, que han demostrado ser muy útiles en este contexto. Se espera que la información proporcionada aquí promueva investigaciones futuras sobre la química contenida en nuestra taza de café matutina.

Unveiling the Neuroprotective Potential of Date Palm (Phoenix dactylifera): A Systematic Review

Background: Neurodegenerative diseases primarily afflict the elderly and are characterized by a progressive loss of neurons. Oxidative stress is intricately linked to the advancement of these conditions. This study focuses on Phoenix dactylifera (P. dactylifera; Family: Arecaceae), commonly known as "Ajwa," a globally cultivated herbal plant renowned for its potent antioxidant properties and reported neuroprotective effects in pharmacological studies. Method: This comprehensive systematic review delves into the antioxidant properties of plant extracts and their phytochemical components, with a particular emphasis on P. dactylifera and its potential neuroprotective benefits. Preferred reporting items for systemic reviews and meta-analysis (PRISMA) were employed to review the articles. Results: The study includes 269 articles published in the literature and 17 were selected after qualitative analysis. The growing body of research underscores the critical role of polyphenolic compounds found in P. dactylifera, which significantly contribute to its neuroprotective effects through antioxidant mechanisms. Despite emerging insights into the antioxidant actions of P. dactylifera, further investigation is essential to fully elucidate the specific pathways through which it confers neuroprotection. Conclusions: Like many other plant-based supplements, P. dactylifera's antioxidant effects are likely mediated by synergistic interactions among its diverse bioactive compounds, rather than by any single constituent alone. Therefore, additional preclinical and clinical studies are necessary to explore P. dactylifera's therapeutic potential comprehensively, especially in terms of its targeted antioxidant activities aimed at mitigating neurodegenerative processes. Such research holds promise for advancing our understanding and potentially harnessing the therapeutic benefits of P. dactylifera in neuroprotection.

A lipidomic study on the lens epithelial cells of patients with age related cataracts

Age related cataracts (ARC) represent the main reason for blindness globally. The lens epithelial cells (LECs) participate not only in the metabolism of many substances in the lens but also in maintaining lens transparency. This study used lipidomics to investigate the metabolic differences in LECs of ARC patients with different severity, aiming at identifying potential metabolic biomarkers of ARC. Patients diagnosed with ARC and underwent cataract surgery at Shanghai Tongren Hospital were selected to participate in this study, which were classified as mild ARC group and severe ARC group. During their cataract surgery, anterior lens capsules(LCs) containing LECs were obtained. The lipidomics of LECs were analyzed using the liquid chromatography‑mass spectrometry (LC-MS). Potential pathways of lipids were searched for using databases such as the Kyoto Encyclopedia of Genes and Genomes (KEGG) and MetaboAnalyst platform. In LEC lipids, 26 lipids have been identified as potential biomarkers between mild ARC and severe ARC, with AUC values of 0.67-0.94. The pathway analysis results revealed that the Glycerophospholipid (GPL) metabolism was significantly influenced, indicating that these metabolic markers contribute significantly to regulating this pathway. The LEC metabolic spectrum demonstrates a proficient ability to differentiate between patients with varying levels of cataracts. Herein, we have successfully identified potential metabolic biomarkers and pathways that have proven to be valuable in enhancing our understanding of ARC pathogenesis. The finding has translational value for developing new cataract treatment methods in the future.

Impact of COVID-19 pandemic on ocular disease: KNHANES 2015-2021

The aim of this study was to evaluate the impact of COVID-19 on ocular diseases and changes in risk factors before and after the COVID-19 pandemic. This study was conducted using data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2015-2021, a national cross-sectional health examination and survey. Associations between ocular diseases and risk factors were determined using the chi-squared test and logistic regression analysis. Bivariable adjusted logistic regression analysis was performed to examine the odds ratio (OR) and 95% confidence interval (CI) to evaluate of the impact of COVID-19 on ocular diseases. Individuals were divided into two age groups (< 60 and ≥ 60 years). A total of 50,158 people were diagnosed, of whom 7270 were diagnosed with cataract, 921 with glaucoma, and 439 with age-related macular degeneration (AMD). Risk factors for cataract were COVID-19 pandemic (OR 1.161), hypertension (OR 1.608), diabetes (OR 1.573), dyslipidemia (OR 1.167), stroke (OR 1.272), and depression (OR 1.567). Risk factors for AMD were COVID-19 pandemic (OR 1.600), dyslipidemia (OR 1.610), and depression (OR 1.466). Risk factors for glaucoma were hypertension (OR 1.234), dyslipidemia (OR 1.529), diabetes (OR 1.323), and depression (OR 1.830). The COVID-19 pandemic was a risk factor for cataracts and AMD, but not for glaucoma. Cataracts and AMD may be more influenced by the acquired health conditions or the environment.

Preservation of Mitochondrial Function by SkQ1 in Skin Fibroblasts Derived from Patients with Leber's Hereditary Optic Neuropathy Is Associated with the PINK1/PRKN-Mediated Mitophagy

Increased or altered mitochondrial ROS production in the retinal ganglion cells is regarded as the chief culprit of the disease-causing Leber's hereditary optic neuropathy (LHON). SkQ1 is a rechargeable mitochondria-targeted antioxidant with high specificity and efficiency. SkQ1 has already been used to treat LHON patients, and a phase 2a randomized clinical trial of SkQ1 has demonstrated improvements in eyesight. However, the underlying mechanism of SkQ1 in LHON remains unclear. This study aimed to assess the effects and molecular mechanism of SkQ1 in the preservation of mitochondrial function using skin fibroblasts derived from LHON patients. Our study found that SkQ1 could reduce ROS production and stabilize the mitochondrial membrane. Mechanistically, through network pharmacology and molecular docking, we identified the key targets of SkQ1 as SOD2 and PINK1, which play crucial roles in redox and mitophagy. SkQ1 interacted with PINK1 and downregulated its expression to balance mitochondrial homeostasis. Collectively, the findings of our study reveal that by regulating PINK1/PRKN-mediated mitophagy, SkQ1 preserves mitochondrial function in LHON fibroblasts. The data indicate that SkQ1 may be a novel therapeutic intervention to prevent the progression of LHON.

Anti-Cataract Effect of the Traditional Aqueous Extract of Yerba Mate (Ilex paraguariensis A. St.-Hil.): An In Ovo Perspective

INTRODUCTION

The therapeutic effect of different doses of the traditional aqueous extract of dried leaves of yerba mate (Ilex paraguariensis A. St.-Hil.) was investigated in an experimental cataract model in chicken embryos.

METHODS AND RESULTS

LC-MS/MS analysis allowed the identification and quantification of 53 metabolites. In the hydrocortisone-induced cataract model, lenses were examined morphologically after treatment and parameters related to oxidative stress (total antioxidant/oxidant status (TAS/TOS), glutathione (GSH), and malondialdehyde (MDA)) were evaluated. Antiproliferative cell nuclear antigen (PCNA) and caspase-3 H-scores were determined and crystallin alpha A (CRYAA) gene expression in the lenses was measured by RT-PCR. The degree of cataract decreased in all treatment groups. While there was no significant difference in TAS levels compared to the negative control, TOS, GSH, and MDA levels were dose-dependently regulated. Treatment groups other than the high-dose group regulated the decrease in PCNA and the increase in caspase-3. CRYAA gene expression increased significantly only at the lowest dose.

CONCLUSION

YM, which is becoming increasingly popular as a traditional tea, showed a therapeutic effect on hydrocortisone-induced cataracts in chicken embryos at relatively low doses.

Nanomedicines for Dry Eye Syndrome: Targeting Oxidative Stress with Modern Nanomaterial Strategies

Dry eye syndrome (DES) is a dynamic, chronic disease of the ocular surface and ocular appendages caused by inflammation. The most common symptoms include redness, itching, and blurred vision, resulting from dysfunction of the meibomian glands and impaired tear-film production. Factors contributing to the development of DES include environmental elements, such as UV radiation, and internal elements, such as hormonal imbalances. These factors increase oxidative stress, which exacerbates inflammation on the surface of the eye and accelerates the development of DES. In recent years, the incidence of DES has risen, leading to a greater need to develop effective treatments. Current treatments for dry eye are limited and primarily focus on alleviating individual symptoms, such as reducing inflammation of the ocular surface. However, it is crucial to understand the pathomechanism of the disease and tailor treatment to address the underlying causes to achieve the best possible therapeutic outcomes. Therefore, in this review, we analyzed the impact of oxidative stress on the development of DES to gain a better understanding of its pathomechanism and examined recently developed nanosystems that allow drugs to be delivered directly to the disease site.

Epigenetics research in eye diseases: a bibliometric analysis from 2000 to 2023

CLINICAL RELEVANCE

A bibliometric analysis is a quantitative study that utilises methods such as citation analysis to evaluate research performance. A bibliometric analysis could provide a valuable reference for ophthalmic researchers to understand the trends in epigenetics research.

BACKGROUND

The number of studies on epigenetics in eye diseases has exceeded 5,000, but the progress and scope of epigenetic research on eye diseases remain unclear. The study aimed to bibliometrically analyse epigenetic research conducted in eye diseases.

METHODS

Studies concerning epigenetic research on eye diseases from 2000-2023 were searched using the Web of Science Core Collection. Following this, the included studies were analysed for citations, journals, keywords, authors, and countries, using the Bibliometrix package in R Studio.

RESULTS

In total, 3758 studies were included in the analysis, including 3099 original articles, 599 reviews, 11 editorials, and 49 early access articles. Investigative Ophthalmology & Visual Science was the most published journal with 185 articles, and Proceedings of the National Academy of Sciences of the United States of America was the most cited journal, with 8727 citations. The journal with the highest h-index was Oncogene (h-index = 38).Renu A Kowluru from the Kresge Eye Institute, Wayne State University, Detroit, USA, had the most citations with 1,690 and the highest h-index (h-index = 23). China and the USA were the countries with the highest number of publications (1739) and total citations (40533), respectively. Furthermore, from 2000-2023, the top five frequent research topics were diabetic retinopathy, 522; microribonucleic acid, 469; retinoblastoma, 370; apoptosis, 268; and epigenetics, 206.

CONCLUSIONS

The results of this bibliometric study provide the current status and trends of epigenetic research in eye diseases and will help researchers identify areas of current interest in the field, which should help highlight new research directions.

Longevity factor FOXO3a: A potential therapeutic target for age-related ocular diseases

The forkhead box protein O3 (FOXO3a) belongs to the subgroup O of the forkhead transcription factor family and plays an important role in regulating the aging process by participating in the regulation of various life processes, including cell cycle arrest, apoptosis, autophagy, oxidative stress, and DNA repair. The eye is an organ that is affected by aging earlier. However, the functional role and potential clinical applications of FOXO3a in age-related eye diseases have not received widespread attention and lacked comprehensive and clear clarification. In this review, we demonstrated the relationship between FOXO3a and visual system health, summarized the functional roles of FOXO3a in various eye diseases, and potential ocular-related therapies and drugs targeting FOXO3a in visual system diseases through a review and summary of relevant literature. This review indicates that FOXO3a is an important factor in maintaining the normal function of various tissues in the eye, and is closely related to the occurrence and development of ophthalmic-related diseases. Based on its vital role in the normal function of the visual system, FOXO3a has potential clinical application value in related ophthalmic diseases. At present, multiple molecules and drugs targeting FOXO3a have been reported to have the potential for the treatment of related ophthalmic diseases, but further clinical trials are needed. In conclusion, this review can facilitate us to grasp the role of FOXO3a in the visual system and provide new views and bases for the treatment strategy research of age-related eye diseases.

LSD1 inhibition by tranylcypromine hydrochloride reduces alkali burn-induced corneal neovascularization and ferroptosis by suppressing HIF-1α pathway

Background

Corneal neovascularization (CNV) is a sight-threatening condition that necessitates epigenetic control. The role of lysine-specific demethylase 1 (LSD1) in CNV remains unclear, despite its established significance in tumor angiogenesis regulation.

Methods

An alkali burn-induced CNV mouse model was used in vivo. The effects of LSD1 inhibitor tranylcypromine hydrochloride (TCP) were examined through slit lamp, histological staining, and immunofluorescence. The expression of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were assessed in corneal tissues. Oxidative stress and ferrous ion expression during CNV were determined using 4-HNE, GPX4, and FerroOrange staining. In vitro, a hypoxia-reoxygenation (H/R) model was established using human umbilical vein endothelial cells (HUVECs) to study LSD1 or hypoxia-inducible factor (HIF-1α) knockdown and lentiviral overexpression of HIF-1α. The effects on HUVECs migration, invasion, and angiogenesis were evaluated through cell scratching assay, transwell migration assay and tube formation assay. The role of ferroptosis was investigated using ROS staining, FerroOrange staining, and key ferroptosis proteins. Further, The JAK2/STAT3 pathway's involvement in CNV regulation was explored through in vivo experiments with subconjunctival injection of AG490.

Results

The results showed a substantial correlation between corneal damage and LSD1 levels. In addition, HIF-1α expression was also elevated after alkali burns, and subconjunctival injection of TCP reduced corneal inflammation and neovascularization. Corneal alkali burns increased ROS levels and reduced antioxidative stress indicators, accompanied by elevated ferrous ion levels, which were reversed by TCP injection. In vitro, TCP or siRNAs inhibited H/R-induced ferroptosis and angiogenesis in HUVECs by affecting specific protein expressions and MDA, SOD, and GSH levels. HIF-1α levels, associated with ROS production, ferroptosis, and angiogenesis, increased during H/R, but were reversed by TCP or siRNA administration. HIF-1α overexpression counteracted the effects of LSD1 inhibition. Additionally, AG490 injection effectively reduced HIF-1α and VEGFA expression in the CNV model.

Discussion

These findings suggest that LSD1 inhibition via the HIF-1α-driven pathway prevents angiogenesis, oxidative stress, and ferroptosis in corneal alkali burn-induced CNV, highlighting LSD1 as a potential therapeutic target.

Achyranthis radix Extract Enhances Antioxidant Effect of Placenta-Derived Mesenchymal Stem Cell on Injured Human Ocular Cells

Age-related ocular diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy are major causes of irreversible vision impairment in the elderly. Conventional treatments focus on symptom relief and disease slowdown, often involving surgery, but fall short of providing a cure, leading to substantial vision loss. Regenerative medicine, particularly mesenchymal stem cells (MSCs), holds promise for ocular disease treatment. This study investigates the synergistic potential of combining placenta-derived MSCs (PD-MSCs) with Achyranthis radix extract (ARE) from Achyranthes japonica to enhance therapeutic outcomes. In a 24-h treatment, ARE significantly increased the proliferative capacity of PD-MSCs and delayed their senescence (* p < 0.05). ARE also enhanced antioxidant capabilities and increased the expression of regeneration-associated genes in an in vitro injured model using chemical damages on human retinal pigment epithelial cell line (ARPE-19) (* p < 0.05). These results suggest that ARE-primed PD-MSC have the capability to enhance the activation of genes associated with regeneration in the injured eye via increasing antioxidant properties. Taken together, these findings support the conclusion that ARE-primed PD-MSC may serve as an enhanced source for stem cell-based therapy in ocular diseases.

The Prodrug DHED Delivers 17β-Estradiol into the Retina for Protection of Retinal Ganglion Cells and Preservation of Visual Function in an Animal Model of Glaucoma

We report a three-pronged phenotypic evaluation of the bioprecursor prodrug 10β,17β-dihydroxyestra-1,4-dien-3-one (DHED) that selectively produces 17β-estradiol (E2) in the retina after topical administration and halts glaucomatous neurodegeneration in a male rat model of the disease. Ocular hypertension (OHT) was induced by hyperosmotic saline injection into an episcleral vein of the eye. Animals received daily DHED eye drops for 12 weeks. Deterioration of visual acuity and contrast sensitivity by OHT in these animals were markedly prevented by the DHED-derived E2 with concomitant preservation of retinal ganglion cells and their axons. In addition, we utilized targeted retina proteomics and a previously established panel of proteins as preclinical biomarkers in the context of OHT-induced neurodegeneration as a characteristic process of the disease. The prodrug treatment provided retina-targeted remediation against the glaucomatous dysregulations of these surrogate endpoints without increasing circulating E2 levels. Collectively, the demonstrated significant neuroprotective effect by the DHED-derived E2 in the selected animal model of glaucoma supports the translational potential of our presented ocular neuroprotective approach owing to its inherent therapeutic safety and efficacy.

Antioxidant effect of gallic acid on retinal ganglion cells in glaucoma model

To evaluate the protective effect of gallic acid on the optic nerve by studying the inhibitory effect of gallic acid on oxidative stress in retinal ganglion cells. 100 male SD rats were randomly divided into four groups: normal control group, simple high IOP group, 0.5% gallic acid experimental group, and 1% gallic acid experimental group. HE staining, immunofluorescence, DHE staining, Western blot, and q-PCR were used to observe the antioxidant effect of gallic acid on the retina of acute ocular hypertension rats. HE staining of the retina of SD rats confirmed that the nucleus of RGCs was clear, the thickness of the RNFL was regular in the normal control group, and the nucleus of RGCs was ruptured and lysed in the simple high intraocular pressure (IOP) group and the gallic acid group, and the thickness of the RNFL was significantly thickened, but the thickness of the RNFL in the gallic acid group was significantly reduced compared with that in the simple high IOP group (p < 0.05). DHE staining showed that ROS content in the simple high IOP group was significantly increased compared with the normal control group, and ROS content was significantly decreased after the application of gallic acid (p < 0.05). Immunofluorescence staining with Brn-3a antibody confirmed that the number of RGCs was significantly reduced in the simple high IOP group compared with the normal control group, whereas after application of gallic acid, the number of RGCs was significantly more in the gallic acid group than in the simple high IOP group (p < 0.05). Western Blot and q-PCR confirmed that hypoxia-inducing factor 1α (HIF-1α) protein content and transcription level were significantly increased in the retinal tissue of the simple high IOP group, and gallic acid could inhibit HIF-1α protein content (p < 0.05) and reduce transcription factor level (p < 0.05). Gallic acid exerts a protective effect on RGC by inhibiting oxidative stress in rats with acute IOP elevation.

Famine exposure in early life increases risk of cataracts in elderly stage

Background

Epidemiological studies have shown that early-life nutritional deficiencies are associated with an increased risk of diseases later in life. This study aimed to explore the correlation between famine exposure during the early stages of life and cataracts.

Methods

We included 5,931 participants from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) 2018 cross-sectional data in our study. Subjects were categorized into three groups by their age during the famine: adulthood group, school age famine exposure group, and teenage famine exposure group. Utilizing binary logistic regression models, we investigated the relationship between early-life famine exposure and cataracts.

Results

Compared to the adulthood group, both the school age exposure group (OR = 2.49, 95%CI = 1.89-3.27) and teenage exposure group (OR = 1.45, 95%CI = 1.20-1.76) had a heightened risk of developing cataracts in elderly stage. And the sex differences in the impact of famine during early years on elderly cataract risk were observed, particularly indicating a higher risk among women who experienced childhood famine compared to men with similar exposure.

Conclusion

Famine exposure during the early stages of life is associated with a heightened risk of developing cataracts in old age. To prevent cataracts in elderly individuals, particularly in females, measures should be taken to address nutritional deficiencies in these specific periods.

MicroRNA-204-5p Attenuates Oxidative Stress, Apoptosis and Inflammation by Targeting TXNIP in Diabetic Cataract

Diabetic cataract (DC) is a major cause of blindness in diabetic patients and it is characterized by early onset and rapid progression. MiR-204-5p was previously identified as one of the top five down-regulated miRNAs in human DC lens tissues. We aimed to determine the expression of miR-204-5p in human lens epithelial cells (HLECs) and explore its effects and mechanisms in regulating the progression of DC. The expression of miR-204-5p in the anterior capsules of DC patients and HLECs was examined by RT-qPCR. Bioinformatics tools were then used to identify the potential target of miR-204-5p. The relationship between miR-204-5p and the target gene was confirmed through a dual luciferase reporter assay. Additionally, the regulatory mechanism of oxidative stress, apoptosis, and inflammation in DC was investigated by overexpressing miR-204-5p using miR-204-5p agomir. The expression of miR-204-5p was downregulated in the anterior capsules of DC patients and HLECs. Overexpression of miR-204-5p reduced ROS levels, pro-apoptosis genes (Bid, Bax, caspase-3), and IL-1β production in HG-treated HLECs. TXNIP was the direct target of miR-204-5p by dual luciferase reporter assay. Therefore, this study demonstrated that miR-204-5p effectively reduced oxidative damage, apoptosis, and inflammation in HLECs under HG conditions by targeting TXNIP. Targeting miR-204-5p could be a promising therapeutic strategy for the potential treatment of DC.

The significance of precisely regulating heme oxygenase-1 expression: Another avenue for treating age-related ocular disease?

Aging entails the deterioration of the body's organs, including overall damages at both the genetic and cellular levels. The prevalence of age-related ocular disease such as macular degeneration, dry eye diseases, glaucoma and cataracts is increasing as the world's population ages, imposing a considerable economic burden on individuals and society. The development of age-related ocular disease is predominantly triggered by oxidative stress and chronic inflammatory reaction. Heme oxygenase-1 (HO-1) is a crucial antioxidant that mediates the degradative process of endogenous iron protoporphyrin heme. It catalyzes the rate-limiting step of the heme degradation reaction, and releases the metabolites such as carbon monoxide (CO), ferrous, and biliverdin (BV). The potent scavenging activity of these metabolites can help to defend against peroxides, peroxynitrite, hydroxyl, and superoxide radicals. Other than directly decomposing endogenous oxidizing substances (hemoglobin), HO-1 is also a critical regulator of inflammatory cells and tissue damage, exerting its anti-inflammation activity through regulating complex inflammatory networks. Therefore, promoting HO-1 expression may act as a promising therapeutic strategy for the age-related ocular disease. However, emerging evidences suggest that the overexpression of HO-1 significantly contributes to ferroptosis due to its dual nature. Surplus HO-1 leads to excessive Fe2+ and reactive oxygen species, thereby causing lipid peroxidation and ferroptosis. In this review, we elucidate the role of HO-1 in countering age-related disease, and summarize recent pharmacological trials that targeting HO-1 for disease management. Further refinements of the knowledge would position HO-1 as a novel therapeutic target for age-related ocular disease.

Aqueous humor perturbations in chronic smokers: a proteomic study

The detrimental effects of smoking are multisystemic and its effects on the eye health are significant. Smoking is a strong risk factor for age-related nuclear cataract, age-related macular degeneration, glaucoma, delayed corneal epithelial healing and increased risk of cystoid macular edema in patients with intermediate uveitis among others. We aimed to characterize the aqueous humor (AH) proteome in chronic smokers to gain insight into its perturbations and to identify potential biomarkers for smoking-associated ocular pathologies. Compared to the control group, chronic smokers displayed 67 (37 upregulated, 30 downregulated) differentially expressed proteins (DEPs). Analysis of DEPs from the biological point of view revealed that they were proteins involved in complement activation, lymphocyte mediated immunity, innate immune response, cellular oxidant detoxification, bicarbonate transport and platelet degranulation. From the molecular function point of view, DEPs were involved in oxygen binding, oxygen carrier activity, hemoglobin binding, peptidase/endopeptidase/cysteine-type endopeptidase inhibitory activity. Several of the upregulated proteins were acute phase reactant proteins such as clusterin, alpha-2-HS-glycoprotein, fibrinogen, alpha-1-antitrypsin, C4b-binding protein and serum amyloid A-2. Further research should confirm if these proteins might serve as biomarkers or therapeutic target for smoking-associated ocular diseases.

Nanozymes for Treating Ocular Diseases

Nanozymes, characterized by their nanoscale size and enzyme-like catalytic activities, exhibit diverse therapeutic potentials, including anti-oxidative, anti-inflammatory, anti-microbial, and anti-angiogenic effects. These properties make them highly valuable in nanomedicine, particularly ocular therapy, bypassing the need for systemic delivery. Nanozymes show significant promise in tackling multi-factored ocular diseases, particularly those influenced by oxidation and inflammation, like dry eye disease, and age-related macular degeneration. Their small size, coupled with their ease of modification and integration into soft materials, facilitates the effective penetration of ocular barriers, thereby enabling targeted or prolonged therapy within the eye. This review is dedicated to exploring ocular diseases that are intricately linked to oxidation and inflammation, shedding light on the role of nanozymes in managing these conditions. Additionally, recent studies elucidating advanced applications of nanozymes in ocular therapeutics, along with their integration with soft materials for disease management, are discussed. Finally, this review outlines directions for future investigations aimed at bridging the gap between nanozyme research and clinical applications.

Breaking Barriers: Nanomedicine-Based Drug Delivery for Cataract Treatment

Cataract is a leading cause of blindness globally, and its surgical treatment poses a significant burden on global healthcare. Pharmacologic therapies, including antioxidants and protein aggregation reversal agents, have attracted great attention in the treatment of cataracts in recent years. Due to the anatomical and physiological barriers of the eye, the effectiveness of traditional eye drops for delivering drugs topically to the lens is hindered. The advancements in nanomedicine present novel and promising strategies for addressing challenges in drug delivery to the lens, including the development of nanoparticle formulations that can improve drug penetration into the anterior segment and enable sustained release of medications. This review introduces various cutting-edge drug delivery systems for cataract treatment, highlighting their physicochemical properties and surface engineering for optimal design, thus providing impetus for further innovative research and potential clinical applications of anti-cataract drugs.

Risk Factors of Age-Related Macular Degeneration in a Population-Based Study: Results from SHIP-TREND-1 (Study of Health in Pomerania-TREND-1)

BACKGROUND Age-related macular degeneration (AMD) is the most common cause of visual impairment in the elderly population in industrialized countries. The Study of Health in Pomerania (SHIP) with its cohort SHIP-TREND was designed to investigate risk factors and clinical disorders in the general population of northeast Germany. This work focused on the first follow-up of SHIP-TREND and determined associated modifiable risk factors of AMD. Modifying risk factors is important to slow the progression of early AMD as there is currently no treatment for the late stage of geographic atrophy. Understanding AMD-associated risk factors also plays an important role in the development of therapeutic concepts. MATERIAL AND METHODS Between 2016 and 2019, data were collected from a total of 2507 initially randomly selected subjects from the general population aged 28 to 89 years. Non-mydriatic fundus photography of the right eye was performed in 2489 subjects. Grading of AMD was performed using the Rotterdam classification system. RESULTS We included 1418 gradable fundus photographs in the analysis. The risk of AMD changes increased with age and was positively correlated with HDL cholesterol, fT3, and low educational level. In men, BMI and cigarette smoking were also positively associated with AMD changes. CONCLUSIONS This study emphasizes the consideration of various metabolic pathways for the development of therapeutic concepts.

Effects of topical ketorolac tromethamine on tear parameters, meibography, goblet cell density, and conjunctival oxidative stress in healthy dogs

OBJECTIVES

The objective of the study was to evaluate whether a twice-daily instillation of 0.45% preservative-free ketorolac tromethamine (FKT) or 0.4% benzalkonium chloride-preserved ketorolac tromethamine (BACKT), every 12 h for 30 days may affect tear film parameters and the meibography in healthy dogs. Additionally, we assessed whether the same treatments irritated the ocular surface, affected goblet cell density (GCD), and the levels of oxidative stress biomarkers (OSB) in the conjunctiva of the same dogs.

PROCEDURES

Experimental and masked comparison study. In 11 healthy dogs baseline values of the lipid layer thickness, tear meniscus height, non-invasive tear breakup time (NI-TFBT), and the meibomian gland (MG) loss were assessed by OSAvet®. For each dog, one eye received 40 μL of BACKT, while the other received 40 μL FKT, every 12 h for 30 consecutive days. Tear parameters and meibography were repeated 15, 30, and 60 days post-treatments. Conjunctival hyperemia and blepharospasm were monitored at the same time points. At baseline and Day 30, a conjunctival biopsy was collected for GCD and OSB determination.

RESULTS

Conjunctival hyperemia and blepharospasm were not observed. At Day 15, the MG loss increased only in FKT-treated eyes (p < .001). On Day 30, both treatment groups showed increased MG loss, shortened NI-TFBT, and reduced GCD and catalase (p < .05). At Day 30, BACKT-treated eyes showed lower levels of superoxide dismutase (SOD) (p = .006) and higher levels of malondialdehyde (MDA) (p = .02). Differences between treatments were not observed for any parameter at any time point (p > .05). 60 days after treatment, OSAvet® parameters tended to return to values assessed at baseline; however, significant differences remained for MG loss (p < .05).

CONCLUSIONS

Twice-daily instillation of KT, containing or not BAC, for 30 consecutive days shortened NI-TFBT, decreased GCD, and increased the MG loss in healthy dogs. KT should be used with caution when prescribed for long periods, particularly in patients with tear film abnormalities. However, future controlled studies using KT, BAC, and other topical NSAIDs are indicated to further support this finding.

The Association between Ovarian Cancer and the Incidence of Newly Developed Dry Eye Disease: A Nationwide Population-Based Study

We aim to investigate the potential correlation between the presence of ovarian cancer and the development of dry eye disease (DED) via the usage of the Longitudinal Health Insurance Database (LHID) of Taiwan. A retrospective cohort study was executed, and patients with ovarian cancer were selected according to the diagnostic and procedure codes. One ovarian cancer patient was matched to four non-ovarian cancer participants which served as control group, and a total of 4992 and 19,968 patients constructed the ovarian cancer and control groups, respectively. The primary outcome in the current study is the development of DED according to the diagnostic and procedure codes. Cox proportional hazard regression was utilized to produce the adjusted hazard ratio (aHR) and related 95% confidence interval (CI) of DED between the two groups. There were 542 and 2502 DED events observed in the ovarian cancer group and the control group, respectively. The ovarian cancer group illustrated a significantly higher incidence of DED development than the control group after the adjustment of several confounders (aHR: 1.10, 95% CI: 1.01-1.21, p = 0.040). In the subgroup analysis stratified by age, ovarian cancer patients aged older than 60 years showed a higher incidence of DED compared to the non-ovarian cancer population (aHR: 1.19, 95% CI: 1.08-1.28, p = 0.011). In addition, ovarian cancer patients with a disease duration longer than five years also showed higher incidence of DED formation than the non-ovarian cancer population (aHR: 1.13, 95% CI: 1.04-1.22, p = 0.027). In conclusion, the presence of ovarian cancer is associated with higher incidence of subsequent DED, especially in those older than 60 years and with a disease interval of more than five years.

Revolutionizing eye care: the game-changing applications of nano-antioxidants in ophthalmology

Since the theory of free radical-induced aging was proposed in 1956, it has been constantly proven that reactive oxygen species (ROS) produced by oxidative stress play a vital role in the occurrence and progression of eye diseases. However, the inherent limitations of traditional drug therapy hindered the development of ophthalmic disease treatment. In recent years, great achievements have been made in the research of nanomedicine, which promotes the rapid development of safe theranostics in ophthalmology. In this review, we focus on the applications of antioxidant nanomedicine in the treatment of ophthalmology. The eye diseases were mainly classified into two categories: ocular surface diseases and posterior eye diseases. In each part, we first introduced the pathology of specific diseases about oxidative stress, and then presented the representative application examples of nano-antioxidants in eye disease therapy. Meanwhile, the nanocarriers that were used, the mechanism of function, and the therapeutic effect were also presented. Finally, we summarized the latest research progress and limitations of antioxidant nanomedicine for eye disease treatment and put forward the prospects of future development.

Potential therapeutic effects of green tea (Camellia sinensis) in eye diseases, a review

This review aims to evaluate the therapeutic potential of green tea (GT), scientifically named Camellia sinensis, in treating eye diseases. We provide an overview of the ingredients and traditional use of Camellia sinensis, followed by a detailed discussion of its therapeutic uses in various eye diseases, including ocular surface diseases (allergic diseases, dry eye, pterygium, and infections), cataract, glaucoma, uveitis, retinal diseases, and optic nerve diseases. The pharmacologic activities related to ocular diseases, such as anti-vascular endothelial growth factor, aldose reductase inhibitor activity, anti-bacterial, anti-inflammatory, and antioxidant effects are also explored in this review. The dose and route of administration of GT in various studies are discussed. Safety issues related to the use of GT, such as the side effects associated with high doses and long-term use, are also addressed. The review highlights the potential of GT as a natural therapeutic agent for a variety of ocular diseases. Its various pharmacologic activities make it a promising treatment option. However, more well-designed studies are needed to determine the optimal dose and route of administration and to assess its long-term safety and efficacy. Overall, GT appears to be a promising adjunct therapy for various ocular diseases.

Untargeted and temporal analysis of retinal lipidome in bacterial endophthalmitis

Bacterial endophthalmitis is a blinding infectious disease typically acquired during ocular surgery. We previously reported significant alterations in retinal metabolism during Staphylococcus (S) aureus endophthalmitis. However, the changes in retinal lipid composition during endophthalmitis are unknown. Here, using a mouse model of S. aureus endophthalmitis and an untargeted lipidomic approach, we comprehensively analyzed temporal alterations in total lipids and oxylipin in retina. Our data showed a time-dependent increase in the levels of lipid classes, sphingolipids, glycerolipids, sterols, and non-esterified fatty acids, whereas levels of phospholipids decreased. Among lipid subclasses, phosphatidylcholine decreased over time. The oxylipin analysis revealed increased prostaglandin-E2, hydroxyeicosatetraenoic acids, docosahexaenoic acid, eicosapentaenoic acid, and α-linolenic acid. In-vitro studies using mouse bone marrow-derived macrophages showed increased lipid droplets and lipid-peroxide formation in response to S. aureus infection. Collectively, these findings suggest that S. aureus-infection alters the retinal lipid profile, which may contribute to the pathogenesis of bacterial endophthalmitis.

Extract from Aronia melanocarpa, Lonicera caerulea, and Vaccinium myrtillus Improves near Visual Acuity in People with Presbyopia

Presbyopia is a global problem with an estimated 1.3 billion patients worldwide. In the area of functional food applications, dietary supplements or herbs, there are very few reports describing the positive effects of their use. In the available literature, there is a lack of studies in humans as well as on an animal model of extracts containing, simultaneously, compounds from the polyphenol group (in particular, anthocyanins) and iridoids, so we undertook a study of the effects of a preparation composed of these compounds on a condition of the organ of vision. Our previous experience on a rabbit model proved the positive effect of taking an oral extract of Cornus mas in stabilizing the intraocular pressure of the eye. The purpose of this study was to evaluate the effect of an orally administered ternary compound preparation on the status of physiological parameters of the ocular organ. The preparation contained an extract of the chokeberry Aronia melanocarpa, the honeysuckle berry Lonicera caerulea L., and the bilberry Vaccinium myrtillus (hereafter AKB) standardized for anthocyanins and iridoids, as bioactive compounds known from the literature. A randomized, double-blind, cross-over study lasting with a "wash-out" period of 17 weeks evaluated a group of 23 people over the age of 50, who were subjects with presbyopia and burdened by prolonged work in front of screen monitors. The group of volunteers was recruited from people who perform white-collar jobs on a daily basis. The effects of the test substances contained in the preparation on visual acuity for distance and near, sense of contrast for distance and near, intraocular pressure, and conjunctival lubrication, tested by Schirmer test, LIPCOF index and TBUT test, and visual field test were evaluated. Anthocyanins (including cyanidin 3-O-galactoside, delphinidin 3-O-arabinoside, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-arabinoside) and iridoids (including loganin, sweroside, loganic acid) were identified as substances present in the extract obtained by HPLC-MS. The preliminary results showed that the composition of AKB applied orally does not change visual acuity in the first 6 weeks of administration. Only in the next cycle of the study was an improvement in near visual acuity observed in 92.3% of the patients. This may indicate potential to correct near vision in presbyopic patients. On the other hand, an improvement in conjunctival wetting was observed in the Schirmer test at the beginning of week 6 of administration in 80% of patients. This effect was weakened in subsequent weeks of conducting the experiment to 61.5%. The improvement in conjunctival hydration in the Schirmer test shows the potential beneficial effect of the AKB formulation in a group of patients with dry eye syndrome. This is the first study of a preparation based on natural, standardized extracts of chokeberry, honeysuckle berry, and bilberry. Preliminary studies show an improvement in near visual acuity and conjunctival hydration on the Schirmer test, but this needs to be confirmed in further studies.

Protocol for assessing total antioxidant capacity in minimal volumes of varying clinical human samples

Total antioxidant capacity (TAC), representative of the capacity to combat oxidative stress, is closely linked to numerous diseases. Here, we present a protocol for measuring TAC using minimal samples that are stable across varying pH levels and at room temperature. We describe steps for preparing and loading samples and working solutions and conducting and analyzing the colorimetric reaction. Sample sources include aqueous humor, vitreous, tears, and plasma, which allow the protocol to be used in various clinical diagnostic settings. For complete details on the use and execution of this protocol, please refer to publications by Tsao et al. (2022).1,2.

β-caryophyllene attenuates oxidative stress and hepatocellular mitochondrial dysfunction in type-2 diabetic rats induced with high fat and fructose diets

Objective

Hyperglycemia, hyperlipidemia, and systemic resistance to insulin are typical manifestations of type 2 diabetes mellitus. One of the main pathophysiological alterations in insulin-sensitive organs is mitochondrial malfunction associated with oxidative stress and diminished fuel utilization. β-Caryophyllene (BCP) has qualities that are anti-inflammatory, anti-tumor, antioxidant, hypolipidemic, and hypoglycemic. In this work, rats suffering from type 2 diabetes were given a diet high in fat and sugar with the aim of examining the ameliorative effects of BCP on oxidative stress-mediated hepatic mitochondrial dysfunction.

Methods

The diabetic condition was experimentally induced by feeding rats a high-calorie diet. The rats were then administered the recommended doses of BCP and metformin (MET) once every day for 30 days at 200 mg and 50 mg concentrations per kg of body weight, respectively, to prove the hypothesis of the study that BCP ameliorates mitochondrial dysfunction induced by oxidative stress in diabetic rats. Mitochondrial dysfunction can be identified by indicators such as oxidative stress, cardiolipin dienes, membrane phospholipid concentration, and mitochondrial enzymes.

Results

The mitochondria in the liver of rats with diabetes exhibit elevated redox imbalance-related parameters and malfunctioning mitochondria with peroxided cardiolipin, while their amounts of glutathione and phospholipids are lowered. Oxidative stress indices, ameliorated mitochondrial activities, and peroxided cardiolipin were drastically decreased in rats with diabetes treated with BCP or MET.

Conclusions

The present research demonstrated that BCP improved the vital role of mitochondria by reducing free radical dominance in type 2 diabetic experimental rats fed high-fat and high-sugar diets.

A bibliometric and visualized analysis of the pathogenesis of cataracts from 1999 to 2023

Research on the pathogenesis of cataracts is ongoing and the number of publications on this topic is increasing annually. This study offers an overview of the research status, popular topics, and scholarly tendencies in the field of cataract pathogenesis over recent decades，which helps to guide future research directions, and optimize resource allocation. In the present study, we performed a bibliometric analysis of cataract pathogenesis. Publications from January 1, 1999, to December 20, 2023, were collected from the Web of Science Core Collection (WoSCC), and the extracted data were quantified and analyzed. We analyzed and presented the data using Microsoft Excel, VOSviewer, CiteSpace, and Python. In all, 4006 articles were evaluated based on various characteristics, including publication year, authors, countries, institutions, journals, citations, and keywords. This study utilized VOSviewer to conduct visualized analysis, including co-authorship, co-citation, co-occurrence, and network visualization. The CiteSpace software was used to identify keywords with significant bursts of activity. The number of annual global publications climbed from 76 to 277 between 1999 and 2023, a 264.47% rise. Experimental Eye Research published the most manuscripts (178 publications), whereas Investigative Ophthalmology & Visual Science received the most citations (6675 citations). The most influential and productive country, institution, and author were the United States (1244 publications, 54,456 citations), University of California system (136 publications, 5401 citations), and Yao Ke (49 publications, 838 citations), respectively. The top 100 ranked keywords are divided into four clusters through co-occurrence analysis: (1) secondary cataracts, (2) oxidative stress, (3) gene mutations and protein abnormalities, and (4) alteration of biological processes in lens epithelial cells. Further discussions on the four subtopics outline the research topics and trends. In conclusion, the specific mechanism of cataract formation remains a popular topic for future research and should be explored in greater depth.

Glutamate is effective in decreasing opacity formed in galactose-induced cataract model

Although cataract is the leading cause of blindness worldwide, the detailed pathogenesis of cataract remains unclear, and clinically useful drug treatments are still lacking. In this study, we examined the effects of glutamate using an ex vivo model in which rat lens is cultured in a galactose-containing medium to induce opacity formation. After inducing lens opacity formation in galactose medium, glutamate was added, and the opacity decreased when the culture was continued. Next, microarray analysis was performed using samples in which the opacity was reduced by glutamate, and genes whose expression increased with galactose culture and decreased with the addition of glutamate were extracted. Subsequently, STRING analysis was performed on a group of genes that showed variation as a result of quantitative measurement of gene expression by RT-qPCR. The results suggest that apoptosis, oxidative stress, endoplasmic reticulum (ER) stress, cell proliferation, epithelial-mesenchymal transition (EMT), cytoskeleton, and histones are involved in the formation and reduction of opacity. Therefore, glutamate may reduce opacity by inhibiting oxidative stress and its downstream functions, and by regulating the cytoskeleton and cell proliferation.

Antioxidant potential of chlorogenic acid in Age-Related eye diseases

Oxidative stress is an important mechanism of aging, and in turn, aging can also aggravate oxidative stress, which leads to a vicious cycle. In the process of the brain converting light into visual signals, the eye is stimulated by harmful blue-light radiation directly. Thus, the eye is especially vulnerable to oxidative stress and becomes one of the organs most seriously involved during the aging process. Cataracts, age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and dry eye are inextricably linked to the aging process and oxidative stress. Chlorogenic acid (CGA) has been demonstrated to have antioxidant and anti-inflammatory activities, and its validity has been established experimentally in numerous fields, including cardiovascular disease, metabolic disorders, cancers, and other chronic diseases. There has previously been evidence of CGA's therapeutic effect in the field of ophthalmopathy. Considering that many ophthalmic drugs lead to systemic side effects, CGA may act as a natural exogenous antioxidant for patients to take regularly, controlling their condition while minimizing side effects. In this paper, in vitro and in vivo studies of CGA in the treatment of age-related eye diseases are reviewed, and the prospects of CGA's antioxidant application for the eye are discussed. The aim of this review is to summarize the relevant knowledge and provide theoretical support for future research.

Cataract-causing mutations S78F and S78P of γD-crystallin decrease protein conformational stability and drive aggregation

Congenital cataract is the leading cause of childhood blindness, which primarily results from genetic factors. γD-crystallin is the most abundant γ-crystallin and is essential for maintaining lens transparency and refractivity. Numerous mutations in γD-crystallin have been reported with unclear pathogenic mechanism. Two different cataract-causing mutations Ser78Phe and Ser78Pro in γD-crystallin were previously identified at the same conserved Ser78 residue. In this work, firstly, we purified the mutants and characterized for the structural change using fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and size-exclusion chromatography (SEC). Both mutants were prone to form insoluble precipitates when expressed in Escherichia coli strain BL21 (DE3) cells. Compared with wild-type (WT), both mutations caused structural disruption, increased hydrophobic exposure, decreased solubility, and reduced thermal stability. Next, we investigated the aggregation of the mutants at the cellular level. Overexpression the mutants in HLE-B3 and HEK 293T cells could induce aggresome formations. The environmental stresses (including heat, ultraviolet irradiation and oxidative stress) promoted the formation of aggregates. Moreover, the intracellular S78F and S78P aggregates could be reversed by lanosterol. Molecular dynamic simulation indicated that both mutations disrupted the structural integrity of Greek-key motif 2. Hence, our results reveal the vital role of conserved Ser78 in maintaining the structural stability, which can offer new insights into the mechanism of cataract formation.

Oxidative stress in the eye and its role in the pathophysiology of ocular diseases

Oxidative stress occurs through an imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defense mechanisms of cells. The eye is particularly exposed to oxidative stress because of its permanent exposure to light and due to several structures having high metabolic activities. The anterior part of the eye is highly exposed to ultraviolet (UV) radiation and possesses a complex antioxidant defense system to protect the retina from UV radiation. The posterior part of the eye exhibits high metabolic rates and oxygen consumption leading subsequently to a high production rate of ROS. Furthermore, inflammation, aging, genetic factors, and environmental pollution, are all elements promoting ROS generation and impairing antioxidant defense mechanisms and thereby representing risk factors leading to oxidative stress. An abnormal redox status was shown to be involved in the pathophysiology of various ocular diseases in the anterior and posterior segment of the eye. In this review, we aim to summarize the mechanisms of oxidative stress in ocular diseases to provide an updated understanding on the pathogenesis of common diseases affecting the ocular surface, the lens, the retina, and the optic nerve. Moreover, we discuss potential therapeutic approaches aimed at reducing oxidative stress in this context.

Novel Role of Molecular Hydrogen: The End of Ophthalmic Diseases?

Molecular hydrogen (H2) is a colorless, odorless, and tasteless gas which displays non-toxic features at high concentrations. H2 can alleviate oxidative damage, reduce inflammatory reactions and inhibit apoptosis cascades, thereby inducing protective and repairing effects on cells. H2 can be transported into the body in the form of H2 gas, hydrogen-rich water (HRW), hydrogen-rich saline (HRS) or H2 produced by intestinal bacteria. Accumulating evidence suggest that H2 is protective against multiple ophthalmic diseases, including cataracts, dry eye disease, diabetic retinopathy (DR) and other fields. In particular, H2 has been tested in the treatment of dry eye disease and corneal endothelial injury in clinical practice. This medical gas has brought hope to patients suffering from blindness. Although H2 has demonstrated promising therapeutic potentials and broad application prospects, further large-scale studies involving more patients are still needed to determine its optimal application mode and dosage. In this paper, we have reviewed the basic characteristics of H2, and its therapeutic effects in ophthalmic diseases. We also focus on the latest progress in the administration approaches and mechanisms underlying these benefits.

Recent advances in lignin antioxidant: Antioxidant mechanism, evaluation methods, influence factors and various applications

Lignin, a by-product of processing lignocellulosic materials, has a polyphenolic structure and can be used as an antioxidant directly or synergistically with synthetic types of antioxidants, leading to different applications. Its antioxidant mechanism is mainly related to the production of ROS, but the details need to be further investigated. The antioxidant property of lignin is mainly related to the content of phenolic hydroxyl group, but methoxy, purity will also have an effect on it. In addition, different methods to detect the antioxidant properties of lignin have different advantages and disadvantages. In this paper, the antioxidant mechanism of lignin, the methods to determine the antioxidant activity and the progress of its application in various fields are reviewed. In addition, the current research on the antioxidant properties of lignin and the hot directions are provided, and an outlook on the research into the antioxidant properties of lignin is provided to broaden its potential application areas.

Reactive X (where X = O, N, S, C, Cl, Br, and I) species nanomedicine

Reactive oxygen, nitrogen, sulfur, carbonyl, chlorine, bromine, and iodine species (RXS, where X = O, N, S, C, Cl, Br, and I) have important roles in various normal physiological processes and act as essential regulators of cell metabolism; their inherent biological activities govern cell signaling, immune balance, and tissue homeostasis. However, an imbalance between RXS production and consumption will induce the occurrence and development of various diseases. Due to the considerable progress of nanomedicine, a variety of nanosystems that can regulate RXS has been rationally designed and engineered for restoring RXS balance to halt the pathological processes of different diseases. The invention of radical-regulating nanomaterials creates the possibility of intriguing projects for disease treatment and promotes advances in nanomedicine. In this comprehensive review, we summarize, discuss, and highlight very-recent advances in RXS-based nanomedicine for versatile disease treatments. This review particularly focuses on the types and pathological effects of these reactive species and explores the biological effects of RXS-based nanomaterials, accompanied by a discussion and the outlook of the challenges faced and future clinical translations of RXS nanomedicines.