Search Results (1,657)

Background: The retina plays a vital role in vision, and its impairment can cause significant visual deficits. Current retinal disease treatments range from conventional anti-inflammatory drugs to advanced anti-VEGF therapies and monoclonal antibodies. TnP, a novel synthetic peptide in preclinical development, has demonstrated therapeutic potential in chronic inflammatory conditions such as multiple sclerosis and asthma due to its immunomodulatory properties. Using zebrafish—which share significant genetic homology with humans—we investigated TnP’s effects on retinopathy models mimicking diabetic retinopathy (DR) through either cobalt chloride (CoCl₂)-induced hypoxia or light-induced retinal damage (LIRD). Methods: We employed two retinal injury models (CoCl₂-induced hypoxia and LIRD) and subjected them to TnP treatment, assessing the outcomes through visual–motor response testing and histological examination. Results: CoCl₂ exposure impaired swimming activity, while light damage reduced the movement distance. Both models induced distinct retinal morphological changes. Although TnP failed to reverse most injury effects, it specifically restored the inner plexiform layer (IPL)’s thickness. Conclusions: Our findings suggest that TnP may enhance neuronal plasticity by promoting cell proliferation and synaptic connectivity. While showing promise as a therapeutic candidate for retinal and neurodegenerative disorders, TnP might achieve optimal efficacy when combined with complementary treatments. Full article

Hyperglycemia is a key factor in diabetic retinopathy which leads to blindness. O-linked-N-acetylglucosamine (O-GlcNAc) modification changes are linked to various diseases, including diabetic retinopathy. This research aims to study the roles of Txnip and Trx in influencing O-GlcNAc in photoreceptor cells during diabetic retinopathy. A diabetic mouse model and 661w cells, after exposure to high glucose, were employed as models. H&E staining and ERG were used to evaluate the morphology and function of the retina, respectively. Western blotting was used to analyze protein expression, a TUNEL assay was used to measure apoptosis, and a co-immunoprecipitation (CO-IP) assay was used to detect the interactions of protein. In diabetic mice, electroretinogram (ERG) amplitude wave, retinal thickness, and body weight decreased. Glial fibrillary acidic protein (GFAP), Iba1 expression, and blood glucose level increased. In vitro, the percentage of apoptotic cell, Bax, and caspase3 levels increased, and Bcl2 decreased in 661w cells under high-glucose conditions. Moreover, Txnip expression was upregulated, while Trx was downregulated. Additionally, a Western blot analysis revealed that high-glucose exposure led to increased O-GlcNAc modification both in vivo and in vitro. The CO-IP results show that Txnip interacted with O-GlcNAc modifications. S-opsin expression was significantly downregulated in vitro under high-glucose conditions. Knockdown Txnip or upregulation Trx could reverse or delay apoptosis in 661w cells under hyperglycemic conditions. Txnip/Trx is a potential element in regulating photoreceptor apoptosis in diabetic retinopathy. The underlying mechanism is linked to regulation of O-GlcNAc modification in photoreceptor cells in DR. Full article

Background and Objectives: Type 2 diabetes mellitus (T2DM) is a health problem all over the world due to its serious complications such as diabetic nephropathy, diabetic neuropathy, diabetic retinopathy, cardiovascular diseases, and limb amputation. The risk factors for T2DM are environmental, lifestyle, and genetic. The genome-wide association studies (GWASs) have revealed the linkage of certain loci with diabetes mellitus (DM) and its complications. The objective of this study was to examine the association of genetic loci with diabetic nephropathy (DN) in the Saudi population. Materials and Methods: Whole exome sequencing (WES) and bioinformatics analysis, such as Genome Analysis Toolkit, Samtools, SnpEff, Polymorphism Phenotyping v2, and Sorting Intolerant from Tolerant (SIFT), were used to examine the association of gene variations with DN in 26 Saudi patients (18 males and 8 females). Results: The present study showed that there are loci that are probably linked to DM and DN. The genes showed variations that include COCH, PRPF31, PIEZO2, RABL5, CCT5, PLIN3, PDE4A, SH3BP2, GPR108, GPR108, MUC6, CACNA1D, and MAFA. The physiological processes that are potentially affected by these gene variations include insulin signaling and secretion, the inflammatory pathway, and mitochondrial function. Conclusion: The variations in these genes and the dysregulation of these processes may be linked to the development of DM and DN. These findings require further verification in future studies with larger sample sizes and protein functional studies. The results of this study will assist in identifying the genes involved in DM and DN (for example, through genetic counseling) and help in prevention and treatment of individuals or populations at risk of this disease and its complications. Full article

Pregnancy orchestrates profound neurological, hormonal, and anatomical transformations in the maternal brain, preparing it for caregiving and infant bonding. Neuroimaging reveals structural changes such as gray matter reductions and white matter reorganization during pregnancy, followed by partial recovery postpartum. These adaptations are modulated by fluctuating levels of estradiol, progesterone, prolactin, and oxytocin, which coordinate neuroplasticity and behavioral readiness. At the molecular and cellular levels, pregnancy hormones drive synaptic remodeling, neurogenesis, and glial activity. Together, these changes support maternal motivation, attachment, and responsiveness, highlighting the maternal brain’s dynamic plasticity across gestation and the postpartum period. Also, pregnancy induces profound physiological changes, particularly in vascular, hormonal, and neurologic systems, to support maternal and fetal health. While these adaptations are essential, they can predispose pregnant individuals to various neurologic and ophthalmic pathologies. This review explores how pregnancy-related changes—including hypercoagulability, pituitary enlargement, hormonal fluctuations, and immunological modulation—contribute to conditions such as stroke, idiopathic intracranial hypertension, preeclampsia-associated visual disturbances, and demyelinating disorders like neuromyelitis optica spectrum disorder and multiple sclerosis. Additionally, ocular manifestations of systemic diseases like diabetic retinopathy and thyroid orbitopathy are discussed. Understanding these complex interactions is critical for prompt recognition, accurate diagnosis, and appropriate management of vision-threatening and neurologically significant complications during pregnancy. Nevertheless, many aspects of physiological and pathological changes during and after pregnancy remain unknown and warrant further investigation. Full article

Diabetic retinopathy is a complication of diabetes characterized by an extremely low rate of progression. It takes several years to move from the onset of diabetes, both type 1 and type 2, to the development of retinal microaneurysms, then leading to proliferative diabetic retinopathy and vision loss. The recent demonstration that retinal microaneurysms are preceded and, possibly, caused by a subclinical neurodegeneration mainly affecting the neurovascular unit has suggested, on one hand, the possible existence of a previously unknown early neurodegenerative stage of diabetic retinopathy and, on the other, that an early “neuroprotective” treatment could end up preventing the development of the microvascular stages. This review summarizes the present situation in the field and focuses on the prevention of diabetic retinopathy, which seems, for the first time, to be within reach. Full article

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus (DM). Key drivers of DR include mitochondrial dysfunction, oxidative stress, and chronic inflammation, which lead to premature senescence of cells within the retinal vasculature. Senolytics improve outcomes in both animal models and in patients with severe forms of DR. In this review, we discuss (i) the role of endothelial senescence in each stage of DR pathogenesis, (ii) methods for detecting senescence in cultured endothelial cells and retinal vessels, and (iii) potential mechanistic explanations for how cells within retinal vessels resist DM-driven senescence. Full article

Dark adaptometry is a non-invasive functional test that assesses the retina’s ability to recover sensitivity in low-light conditions following photobleaching. This review explores the physiological mechanisms underlying dark adaptation (DA), including photopigment regeneration and the critical role of the retinal pigment epithelium in the visual cycle. We detail clinical protocols for dark adaptometry using modern instruments such as the AdaptDx, highlighting methodological advances that improve testing efficiency and reproducibility. The clinical utility of dark adaptometry is examined across a range of inherited and acquired retinal disorders, including age-related macular degeneration (AMD), retinitis pigmentosa (RP), Stargardt disease, diabetic retinopathy (DR), cone–rod dystrophy (CRD), vitamin A deficiency, and congenital stationary night blindness (CSNB). Dark adaptometry has emerged as a sensitive biomarker capable of detecting functional deficits before structural changes are evident, making it a valuable tool for early diagnosis and monitoring disease progression. However, limitations such as age-related variability, patient compliance, and lack of standardization remain challenges to broader clinical adoption. Continued refinement of dark adaptometry protocols and instrumentation is essential to maximize its diagnostic potential in ophthalmic practice. Full article

Background/Objectives: Uncontrolled or long-standing diabetes can lead to proliferative diabetic retinopathy (PDR), a condition that significantly impairs vision. A subset of patients does not respond adequately to conventional therapies, such as intravitreal injections of anti-vascular endothelial growth factor (VEGF) or laser treatment. This study aims to identify potential biomarkers for alternative treatment pathways in the vitreous and blood of patients with severe PDR. Methods: Vitreous samples were collected from PDR patients (n = 3) undergoing vitrectomy for vitreous hemorrhage and from control patients (n = 9) undergoing ocular surgery for epiretinal membrane or macular holes. Blood samples were collected from a separate group of PDR patients (n = 13) and non-diabetic control patients without retinopathy (n = 13). Medical histories were obtained. Two-stage real-time quantitative polymerase chain reaction (qPCR) was used to evaluate mRNA expression levels of genes potentially implicated in PDR, including HIF2A, PAI-1, TIE1, TIE2, ANGPT2, and VEGFA. Molecular and statistical analyses were performed to compare PDR and control vitreous and blood samples. Results: The PDR vitrectomy group included two females and one male, aged 71–77 years (mean 74 years). All participants had undergone pan-retinal photocoagulation and two had received anti-VEGF injections before vitrectomy. These participants had elevated HbA1c levels. Targeted vitreous gene analysis revealed varying levels of increased expression of all genes examined as compared to the control group. A trend for increased median expression was demonstrated for all examined genes: HIF2A by 1.44-fold (PDR = 2.50, control = 1.74, p = 0.21), PAI-1 by 1.56-fold (PDR = 3.00, control = 1.93, p = 0.37), TIE1 by 1.36-fold (PDR = 2.33, control = 1.72, p = 0.66), TIE2 by 2.06-fold (PDR = 2.81, control = 1.36, p = 0.51), ANGPT2 by 2.93-fold (PDR = 6.32, control = 2.16, p = 0.1), and VEGFA by 3.53-fold (PDR = 3.51, control = 0.99, p = 0.08). PDR blood sample analysis as compared to controls showed a trend for increased expression of VEGFA by 1.2-fold (PDR = 0.88, control = 0.74, p = 0.57), whereas the other examined genes showed a trend of reduced expression; HIF2A decreased by 0.50-fold (PDR = 0.38, control = 0.75, p = 0.07), PAI by 0.51-fold (PDR = 0.35, control = 0.69, p = 0.09), TIE-1 by 0.79-fold (PDR = 0.79, control = 1.00, p = 0.54), TIE-2 by 0.70-fold (PDR = 0.58, control = 0.82, p = 0.34), and ANGPT2 by 0.45-fold (PDR = 0.51, control = 1.15, p = 0.11). Conclusions: Vitreous sample analysis revealed a trend of increased mRNA expression of ANGPT2 and VEGFA in patients with PDR. Blood sample analysis did not show a significant increase of VEGFA mRNA expression but a decreased trend of HIF2A, PAI-1, and ANGPT2 mRNA expression. These trends warrant validation in a larger cohort to explore alternative pathways for targeted treatment. Full article

Diabetic retinopathy (DR) is a leading cause of vision impairment worldwide, necessitating early detection and personalized treatment strategies. Liquid biopsy, a minimally invasive diagnostic tool, offers significant advantages over traditional methods by enabling analysis of biofluids such as blood, tears, aqueous humor, and vitreous humor. This review highlights the advances in liquid biopsy techniques, sample collection methods and their applications in protein detection and metabolomics analysis for DR. It also explores the key protein biomarkers, including vascular endothelial growth factor (VEGF), inflammatory cytokines, and matrix metalloproteinases (MMPs), and investigates the associations between different biofluids. Metabolomics of liquid biopsy is emphasized for its role in identifying metabolic biomarkers linked to DR pathogenesis, providing new insights into disease mechanisms and personalized interventions. The challenges of liquid biopsy, such as technical limitations and the need for standardization, are also discussed. Advances in computational tools, bioinformatics, and artificial intelligence are supposed to further enhance multi-omics integration, thereby improving precision medicine in DR care. This comprehensive review brings attention to the transformative potential of liquid biopsy in DR diagnosis and management, with implications for broader ophthalmic and systemic diseases. Full article

Angiopoietin-like proteins (ANGPTLs) represent a family of secreted glycoproteins that are extensively expressed in vivo and are integral to various pathophysiological processes, including glucose and lipid metabolism, stem cell proliferation, local inflammation, vascular permeability, and angiogenesis. Particularly interesting is ANGPTL4, which has been identified as a significant factor in the development and progression of diabetic retinopathy (DR), thus becoming a central focus of DR research. ANGPTLs modulate metabolic pathways, enhance vascular permeability, and facilitate pathological angiogenesis, in addition to causing intraocular inflammation. As promising molecular targets, ANGPTLs not only serve as biomarkers for predicting the onset and progression of DR but also present therapeutic potential through antibody-based interventions. This paper discusses the pathogenesis of DR and the potential applications of ANGPTLs in early diagnosis and targeted therapy. It provides references for advancing precision diagnosis and personalized treatment strategies through more profound ANGPTLs research in the future. Full article

Diabetic retinopathy (DR) is a leading cause of vision loss in patients with diabetes. While medical treatments like retinal laser photocoagulation, anti-VEGF therapy, and vitrectomy are primary, complementary therapies are gaining increasing attention. Based on the existing literature, a healthy lifestyle, including a balanced diet, stress management techniques, and regular physical activity targeting DR, can help regulate blood sugar levels and improve overall physical and mental health to reduce complications. This article explores physical activities and visual training methods related to DR, emphasizing complementary therapies, even though some of these practices are currently not fully integrated into evidence-based ophthalmology. Low vision exercises and aids help patients make the most of their remaining vision, improving their ability to perform everyday tasks, reducing the impact of vision loss, and promoting independence. There is some evidence that eye-related physiotherapy can improve the quality of life for patients with DR, although selection bias cannot be excluded in the presented studies. Consistent physical activity promotes holistic health, and therapies should be regularly monitored by ophthalmologists. This review further helps integrative healthcare professionals in offering appropriate therapies for rehabilitation purposes in the treatment of ophthalmic diseases, particularly DR. Full article

Background: Microvascular complications in type 2 diabetes (T2D) and cancer share biological pathways, including chronic inflammation, dysregulated angiogenesis, and endothelial dysfunction, yet their impact on cancer risk and mortality remains unclear. This study evaluated whether T2D patients with microvascular complications face increased cancer incidence or cancer-related mortality. Methods: Using the Taiwan National Health Insurance Research Database, we identified individuals newly diagnosed with T2D (2008–2021) and assessed the outcomes with multivariable Cox proportional hazards models. Results: Our findings indicate that T2D patients with diabetic neuropathy, retinopathy, or chronic kidney disease do not have a significantly increased risk of major cancers, including those of the oral cavity, thyroid, breast, respiratory tract, digestive system, or lymphoid tissues. Similarly, microvascular complications were not associated with higher cancer-related mortality. However, microvascular complications significantly increased all-cause mortality in a dose-dependent manner: adjusted hazard ratio (aHR) 1.16 [95% CI: 1.15–1.17] for one complication, aHR 1.42 [1.38–1.45] for two, and aHR 1.71 [1.60–1.83] for three. Conclusions: In this nationwide cohort study, we demonstrate that while microvascular complications are associated with increased all-cause mortality in T2D, they do not appear to elevate cancer risk or cancer-specific mortality. These findings provide crucial epidemiological insights into the relationship between diabetes complications and cancer. Full article

The process of aging exerts profound effects on various physiological systems, leading to the progression of chronic degenerative disorders and pathologies associated with advancing age. Cellular senescence plays a central role in the aging process and the onset of various eye conditions associated with advancing age, including age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, cataracts, and ocular surface disorders. The accumulation of senescent cells (SnCs) and their secretion of pro-inflammatory and tissue-remodeling factors, collectively known as the senescence-associated secretory phenotype (SASP), exacerbate chronic inflammation, oxidative stress, and tissue dysfunction, contributing to disease progression. This study is the first to systematically integrate the multifaceted mechanisms of cellular senescence in ocular diseases, revealing differential regulatory mechanisms of specific signaling pathways across different ocular pathologies, thereby providing novel insights into the pathogenesis of these disorders. SnC-targeted therapies such as senolytics, senomorphics, SASP modulators, mitochondrial-targeted antioxidants, and epigenetic reprogramming are emerging as regenerative therapies, demonstrating potent anti-inflammatory effects, restoration of normal tissue physiology, and successful regeneration of ocular defects in preclinical models and clinical trials, while slowing senescence-associated disease progression. This review not only summarizes the role of cellular senescence in ocular diseases but also delves into potential therapeutic strategies, particularly highlighting novel perspectives for root-cause-targeted therapies from the unique angle of senescence biology, which may pioneer new directions for the treatment of ocular pathologies. Full article

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis throughout the human body, influencing countless physiological and pathological processes, including tumor growth, preeclampsia, and retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). In DR, VEGF promotes retinal neovascularization and intraretinal fluid accumulation, leading to complications like diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). Regular intravitreal anti-VEGF injections are commonly used to manage PDR and DME, though repeated treatments are often required, and efficacy can be limited. AMD, a major cause of vision loss in older adults, is characterized by either dry or wet forms. While the dry form has not been shown to be influenced by VEGF, the choroidal neovascularization of wet AMD has strong associations with VEGF. Current treatment for wet AMD consists primarily of anti-VEGF injections, the gold standard of care, but is limited by varying patient responses, as treatments are often repeated every 4-8 weeks indefinitely. This review explores the pathogenic role of VEGF in both DR and AMD, discussing the molecular mechanisms underlying these diseases and the therapeutic approaches targeting VEGF. Despite advancements, the variability in treatment responses highlights the need for continued research to develop more effective therapies to prevent vision loss and blindness associated with these retinal diseases. Full article

Background: Diabetic macular edema (DME) is the most common cause of vision loss among diabetic patients. The first-line treatments for DME are anti-vascular endothelial growth factor (VEGF)-drugs, while intravitreal steroids are generally reserved for second-line treatment. Limited data exist on the role of optical coherence tomography (OCT) biomarkers as predictors of success in non-responders to anti-VEGF treatment undergoing simultaneous cataract surgery and dexamethasone intravitreal implant (DEX-I). Methods: This study was designed as a retrospective analysis of patients with DME who were refractory to anti-VEGF treatment but underwent cataract surgery and received a DEX-I at the time of surgery. All procedures were performed between May 2021 and February 2024. The best-corrected visual acuity (BCVA) and central subfoveal thickness (CST) were recorded at baseline and at 1 week, 1 month, and 3 months. The following OCT-based biomarkers were also collected: ellipsoid zone (EZ) integrity, disorganization of the retinal inner layers (DRIL), CST, and hyperreflective foci (HRF). Correlations between the baseline biomarkers and the anatomical outcome were analyzed using linear mixed models (LMMs). Results: Eleven patients (eighteen eyes) met the inclusion criteria. The mean CST decreased significantly from 469.4 ± 53.8 µm at baseline, to 373.1 ± 34.7 µm at 1 week (p = 0.002) and 354.4 ± 24.1 µm at 1 month (p = 0.011). The mean BCVA improved significantly from 0.47 LogMAR to 0.33 LogMAR at 1 week (p = 0.001), 0.23 LogMAR at 1 month (p < 0.001), and 0.25 LogMAR at 3 months (p < 0.001). Baseline predictors significantly influencing CST included the presence of DRIL, a disrupted/absent EZ, and a higher CST. Conclusions: The administration of DEX-I for DME refractory to anti-VEGF treatment in patients undergoing cataract surgery promoted functional improvements persisting longer than the anatomical ones. Patients presenting with DRIL, disrupted EZ, and higher CST at baseline may be better candidates for the combination of DEX-I and cataract surgery. Full article