Diabetic Retinopathy in the Aging Population: A Perspective of Pathogenesis and Treatment

Association between age at diagnosis of diabetes and ocular disease: Insights from a recent article

In this article, we discuss Ye et al's recent article on the association between age at diabetes diagnosis and subsequent risk of age-related ocular diseases. The study, which utilized United Kingdom Biobank data, highlighted a strong link between early diabetes onset and major eye conditions, such as cataracts, glaucoma, age-related macular degeneration, and vision loss, independent of glycemic control and disease duration. This finding challenges the previous belief that diabetic eye disease primarily correlates with hyperglycemia. As lifestyles evolve and the age of diabetes diagnosis decreases, understanding this relationship may reveal the complex pathogenesis underlying diabetes-related complications. This editorial summarizes potential mechanisms connecting the age of diabetes onset with four types of ocular diseases, emphasizing the significance of early diagnosis.

The relationship between ON-OFF function and OCT structural and angiographic parameters in early diabetic retinal disease

PURPOSE

This study measured associations between ON and OFF functional indicators and structural optical coherence tomography (OCT) and OCT angiography (OCTA) markers in diabetic retinal disease.

METHODS

Fifty-four participants with type 1 or type 2 diabetes (mean age = 34.1 years; range 18-60) and 48 age-matched controls (mean age = 35.4 years, range 18-59) underwent visual psychophysical testing, OCT and OCTA retinal imaging. Psychophysical tasks measuring (A) contrast increment and decrement sensitivity and (B) response times to increment and decrement targets were assessed as surrogate measures of ON and OFF retinal ganglion cell function.

RESULTS

The group with diabetes had worse foveal contrast increment and decrement thresholds (p = 0.04) and were slower to search for increment and decrement targets relative to controls (p = 0.009). Individuals with diabetes had a less circular foveal avascular zone (FAZ) (p < 0.001) but did not differ from controls in foveal vessel density and FAZ area. Functional and structural outcome measures related to the peripheral retina were also comparable between those with and without diabetes. Functional responses to increments and decrements were not significantly correlated with FAZ circularity or vessel density in individuals with diabetes.

CONCLUSIONS

Diabetic retinal disease results in impaired performance on measures of inferred ON and OFF pathway function in addition to vascular deficits measurable with OCTA. Future longitudinal studies may determine the temporal relationship between these deficits, and whether they predict future diabetic retinopathy.

PRDX4 mitigates diabetic retinopathy by inhibiting reactive gliosis, apoptosis, ER stress, oxidative stress, and mitochondrial dysfunction in Müller cells

Diabetic retinopathy (DR) is a neurovascular complication of diabetes. As a crucial player in the retinal physiology, Müller cells are affected in DR, impairments of Müller cell function lead to retinal malfunctions. Therefore, searching for approaches to mitigate diabetes-induced injury in Müller cells is imperative for delaying DR. Peroxiredoxin 4 (PRDX4), an important endoplasmic reticulum (ER)-resident antioxidant, was explored in this study for its potential protective role against DR. Streptozotocin (STZ)-induced mouse model of diabetes and high glucose (HG)-induced Müller cells were utilized to assess the impact of PRDX4. Compared to wild-type mice, PRDX4 knockout exacerbated retinal neurodegeneration, reactive gliosis, cell apoptosis, endoplasmic reticulum (ER) stress, oxidative stress, and mitochondrial dysfunction in diabetic retinas. Knockdown of PRDX4 aggravated high glucose (HG)-induced reactive gliosis, apoptosis, ER stress, oxidative stress, and mitochondrial dysfunction in Müller cells. Conversely, PRDX4 overexpression in Müller cells protected against HG-induced cell damage. Mechanistically, PRDX4 promoted the degradation of DPP4, which is associated with DR in type 1 diabetics, thereby alleviating HG-stimulated Müller cell abnormalities. Our study indicated that PRDX4 is a crucial protective regulator in DR progression via destabilization of DPP4 protein and suggested enhancement of PRDX4 level may represent a promising approach for treating DR.

MiR-185-5p is Involved in Regulating the Abnormal Proliferation of Retinal Microvascular Endothelial Cells via Targeting CXCR4

PURPOSE

This study aimed to explore the expression profile of miR-185-5p in proliferative DR (PDR), and further evaluate its diagnostic value and possible mechanism of miR-185-5p in PDR.

METHODS

The level of miR-185-5p was detected by qRT-PCR. The ROC curve was established to estimate the diagnostic ability of miR-185-5p. Transwell experiment and cell counting kit-8 (CCK-8) assays were conducted to assess the effect of miR-185-5p on the migration and proliferation of human retinal endothelial cells (HRECs) induced by high glucose. Enzyme linked immunosorbent assay (ELISA) was used to detect the concentrations of inflammatory factors. The luciferase reporter gene experiment was used to prove the interaction between miR-185-5p and CXCR4.

RESULTS

Compared to the control group, the expression of miR-185-5p was significantly up-regulated in both the type 2 diabetes mellitus (T2DM) group and the PDR groups, with higher levels in the PDR group than in the T2DM group. The ROC curve reveals that serum miR-185-5p can distinguish PDR patients from T2DM patients. MiR-185-5p levels in HRECs increased significantly after high glucose induction. High glucose induction also promoted the migration, proliferation and inflammation response of HRECs. However, when the intracellular miR-185-5p level was down-regulated by miR-185-5p inhibitor transfection, these effects were inhibited. The luciferase reporter gene assay showed that miR-185-5p directly targets CXCR4.

CONCLUSION

The expression of miR-185-5p is out of balance in PDR and it may be involved in regulating the migration and proliferation of HRECs by regulating CXCR4.

Tropisetron attenuates high glucose-induced oxidative stress and inflammation in ARPE-19 cells in vitro via regulating SIRT1/ROCK1 signaling

Diabetic retinopathy (DR) is the leading cause of acquired blindness in diabetic patients. Tropisetron (TRO) exerts potent therapeutic effects against diabetic tissues. The present study aimed to investigate the effects of TRO on retinal injury under diabetic condition. Human retinal pigment epithelial cell line ARPE-19 was treated with high glucose (HG) for 48 h to mimic hyperglycemia-induced retinal damage and subsequently treated with multiple concentrations of TRO for therapeutic intervention. Cell viability and lactate dehydrogenase (LDH) release were detected to assess cell damage. The production of inflammatory cytokines and oxidative stress-related factors was evaluated by corresponding commercial kits. Cell apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The expression of inflammation-, apoptosis-, and SIRT1/ROCK1-related proteins was examined using western blot analysis. Additionally, ARPE-19 cells were transfected with over-express ROCK1 (Ov-ROCK1) or pretreatment with SIRT1 inhibitor EX527 to perform the rescue experiments. TRO alleviated cell damage in HG-induced ARPE-19 cells through elevating cell viability and reducing LDH release. HG-caused excessive production of TNF-α, IL-1β and IL-6, ROS, malondialdehyde and decreased superoxide dismutase activity were partly inhibited by TRO treatment. HG-induced cell apoptosis, accompanied with the upregulation of proapoptotic proteins and the downregulation of antiapoptotic proteins, was hindered by TRO treatment. HG led to the loss of SIRT1 and an elevation of ROCK1 in ARPE-19 cells, which was reversed following TRO treatment. Furthermore, pretreatment with EX527 or transfected with Ov-ROCK1 partially abolished the protective role of TRO against inflammation, oxidative stress and cell apoptosis in HG-challenged ARPE-19 cells. TRO exerted a protective role against HG-caused ARPE-19 cells inflammation, oxidative stress and cell apoptosis by regulating SIRT1/ROCK1 axis, suggesting that TRO might be therapeutic agent for alleviating retinal pigment epithelial cell damage in DR.

Frailty and Visual Impairment in Elderly Individuals: Improving Outcomes and Modulating Cognitive Decline Through Collaborative Care Between Geriatricians and Ophthalmologists

Introduction: As life expectancy increases, the prevalence of frailty and eye diseases (cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy) in the elderly global population is rising. Eye diseases and visual impairment not only contribute to a high incidence of falls, fractures, depression, and social isolation but they also herald cognitive decline and frailty (vision-cognitive impairment). Methods: This narrative review explores the relationship between eye diseases, visual impairment, and frailty, their association with cognitive decline, the current approaches in identifying and managing these conditions and the potential role of interdisciplinary care models. Relevant articles were identified by searching the major databases. Result: Eye diseases are common in elderly individuals and can lead to visual impairment and subsequently contribute to falls, fractures, depression, and social isolation. Visual impairment is strongly linked to cognitive decline, which is a key component of frailty. Reduced sensory input from vision loss leads to decreased cognitive stimulation, reduced engagement in activities such as reading, problem-solving, executive function, attention, and social interactions, which are crucial for maintaining cognitive health. This can lead to a form of "sensory deprivation", which accelerates neurodegenerative processes. As cognitive decline progresses, it creates a feedback loop where individuals may struggle to manage their health, adhere to treatment regimens, or seek timely medical care, exacerbating both cognitive impairment and frailty. Additionally, subjective cognitive decline (SCD) is common in older adults with vision loss and may precede clinical dementia. This sense of declining cognitive ability can worsen anxiety and depression, further contributing to frailty. Early intervention has the potential to mitigate the cognitive effects of vision loss (vision-cognitive impairment). Conclusions: Ophthalmologists should play an important role in detecting frailty associated with vision loss. Incorporating frailty assessments into ophthalmic practice can facilitate referrals to geriatric care and early interventions, improving patient outcomes. Geriatricians should be vigilant in identifying visual impairment and referring patients for appropriate ophthalmic investigation and management. Regular vision assessments should be part of comprehensive geriatric evaluations. Future research will assess the beneficial role of community geriatricians in detecting frailty and vision-cognitive impairment. An interdisciplinary and collaborative approach between ophthalmologists and geriatricians can lead to earlier detection, comprehensive management, and improved outcomes in frailty, eye diseases, and cognitive function.

Effects of voluntary and forced physical exercise on the retinal health of aging Wistar rats

Aging is accompanied by an increased prevalence of degenerative conditions, including those affecting ocular health, which significantly impact quality of life and increase the burden on healthcare systems. Among these, retinal aging is of particular concern due to its direct link to vision impairment, a leading cause of disability in the elderly. Vision loss in the aging population is associated with heightened risks of cognitive decline, social isolation, and morbidity. This study addresses the critical gap in our understanding of modifiable lifestyle factors, such as physical exercise, that may mitigate retinal aging and its related pathologies. We investigated the effects of different exercise regimens-voluntary (recreational-type) and forced (high-intensity)-on the retinal health of aging Wistar rats (18-month-old), serving as a model for studying the translational potential of exercise interventions in humans. Male Wistar rats were divided into four groups: a young control (3-month-old) for baseline comparison, an aged sedentary control, an aged group engaging in voluntary exercise via a running wheel in their cage, and an aged group subjected to forced exercise on a treadmill for six sessions of 20 min each per week. After a 6-month experimental period, we assessed retinal function via electroretinography (ERG), measured retinal thickness histologically, and analyzed protein expression changes relevant to oxidative stress, inflammation, and anti-aging mechanisms. Our findings reveal that voluntary exercise positively impacts retinal function and morphology, reducing oxidative stress and inflammation markers while enhancing anti-aging protein expression. In contrast, forced exercise showed diminished benefits. These insights underscore the importance of exercise intensity and preference in preserving retinal health during aging. The study highlights the potential of recreational physical activity as a non-invasive strategy to counteract retinal aging, advocating for further research into exercise regimens as preventative therapies for age-related ocular degenerations.

Adjusting for Glycemic Control in Assessing the Relationship Between Age-Related Macular Degeneration and Diabetic Retinopathy

Purpose Studies regarding the relationship between age-related macular degeneration (AMD) and diabetic retinopathy (DR) conflict: while some support that AMD is protective against DR, others find the opposite. The mechanism by which AMD may protect against DR is unclear. We sought to assess the association between AMD and DR when controlling for glycemic control in patients with diabetes mellitus (DM) type II. Methods We identified 461 unique patients over 55 years old with a diagnosis of DM type II seen in our academic retina clinic in Stony Brook, New York between 12/31/2019 and 12/31/2020. Data were manually extracted and the population was split based on the presence of AMD diagnosis. Multivariate regression analyses were then performed comparing the prevalence of DR between groups while controlling for A1c. Secondary endpoints included demographic differences and smoking status.  Results Among the 461 patients, 118 (25.6%) had a diagnosis of AMD. Compared to patients without AMD, patients with AMD were older (69 vs. 66; OR 1.05; p=0.005) and less likely to have DR (37.3% vs. 59.2%; OR 0.35; p<0.001). There was no difference in average A1c between groups. Conclusion This is the first reported study assessing the relationship between AMD and DR while controlling for A1c. In our population, diagnosis of AMD was associated with significantly reduced odds of having DR. As AMD and DR appear to be related even after holding A1c constant, researchers should use caution when using DR as a surrogate for diabetic control in the context of AMD.

Improved diabetic retinopathy severity classification using squeeze-and-excitation and sparse light weight multi-level attention u-net with transfer learning from xception

AIMS

Diabetic Retinopathy (DR) is a significant cause of vision loss in diabetic patients, making early detection and accurate severity classification essential for effective management and prevention. This study aims to develop an enhanced DR severity classification approach using advanced model architectures and transfer learning to improve diagnostic accuracy and support better patient care.

METHODS

We propose a novel model, Xception Squeeze-and-Excitation Sparse Lightweight Multi-Level Attention U-Net (XceSE_SparseLwMLA-UNet), designed to classify DR severity using fundus images from the Messidor 1 and Messidor 2 datasets. The XceSE_SparseLwMLA-UNet integrates several advanced mechanisms: the Squeeze-and-Excitation (SE) mechanism for adaptive feature recalibration, the Sparse Lightweight Multi-Level Attention (SparseLwMLA) mechanism for effective contextual information integration, and transfer learning from the Xception architecture to enhance feature extraction capabilities. The SE mechanism refines channel-wise feature responses, while SparseLwMLA enhances the model's ability to identify complex DR patterns. Transfer learning utilizes pre-trained weights from Xception to improve generalization across DR severity levels.

RESULTS

The proposed XceSE_SparseLwMLA-UNet model demonstrates superior performance in DR severity classification, achieving higher accuracy and improved multi-class F1 scores compared to existing models. The model's color-coded segmentation outputs offer interpretable visual representations, aiding medical professionals in assessing DR severity levels.

CONCLUSIONS

The XceSE_SparseLwMLA-UNet model shows promise for advancing early DR diagnosis and management by enhancing classification accuracy and providing valuable visual insights. Its integration of advanced architectural features and transfer learning contributes to better patient care and improved visual health outcomes.

Optimization of an Ischemic Retinopathy Mouse Model and the Consequences of Hypoxia in a Time-Dependent Manner

The retina is one of the highest metabolically active tissues with a high oxygen consumption, so insufficient blood supply leads to visual impairment. The incidence of related conditions is increasing; however, no effective treatment without side effects is available. Furthermore, the pathomechanism of these diseases is not fully understood. Our aim was to develop an optimal ischemic retinopathy mouse model to investigate the retinal damage in a time-dependent manner. Retinal ischemia was induced by bilateral common carotid artery occlusion (BCCAO) for 10, 13, 15 or 20 min, or by right permanent unilateral common carotid artery occlusion (UCCAO). Optical coherence tomography was used to follow the changes in retinal thickness 3, 7, 14, 21 and 28 days after surgery. The number of ganglion cells was evaluated in the central and peripheral regions on whole-mount retina preparations. Expression of glial fibrillary acidic protein (GFAP) was analyzed with immunohistochemistry and Western blot. Retinal degeneration and ganglion cell loss was observed in multiple groups. Our results suggest that the 20 min BCCAO is a good model to investigate the consequences of ischemia and reperfusion in the retina in a time-dependent manner, while the UCCAO causes more severe damage in a short time, so it can be used for testing new drugs.

Preliminary research on LncRNA ATP2B2-IT2 in neovascularization of diabetic retinopathy

OBJECTIVE

Diabetic retinopathy (DR) is a common complication of diabetes, and recent findings have shown that long noncoding RNAs (lncRNAs) may be involved in its pathogenesis. Through bioinformatics analysis, we found that lncRNA ATP2B2-IT2 may be involved in this process. This study primarily investigated the expression of the lncRNA ATP2B2-IT2 in human retinal microvascular endothelial cells (HRMECs) under high-glucose conditions and its effects on HRMEC proliferation, migration, and neovascularization.

METHODS

We used RT‒PCR to assess the expression levels of lncRNA ATP2B2-IT2 and vascular endothelial growth factor (VEGF) in HRMECs under normal glucose (5.5 mmol/L) and high glucose (30 mmol/L) conditions. HRMECs were subsequently divided into four groups: the normal glucose (NG), high glucose (HG), high glucose with lncRNA ATP2B2-IT2 silencing (HG + si-lncRNA ATP2B2-IT2), and high glucose with silencing control (HG + si-NC) groups. The expression levels of the lncRNA ATP2B2-IT2 and VEGF in each group were determined using RT‒PCR. Thereafter, cell proliferation, migration, and neovascularization were assessed using CCK-8, Transwell, and tube formation assays, respectively.

RESULTS

RT‒PCR revealed that the expression levels of the lncRNA ATP2B2-IT2 and VEGF were greater in the HG group than in the NG group (P < 0.05). After silencing of the lncRNA ATP2B2-IT2, the expression of VEGF decreased significantly (P < 0.05). Subsequent CCK-8, Transwell, and tube formation assays demonstrated that compared to those in the NG group, the HRMECs in the HG group exhibited significantly increased proliferation, migration, and neovascularization (P < 0.05). However, after silencing of the lncRNA ATP2B2-IT2, the proliferation, migration, and neovascularization of HRMECs were significantly decreased in the HG + si-lncRNA ATP2B2-IT2 group compared to those in the HG group (P < 0.05).

CONCLUSION

LncRNA ATP2B2-IT2 may promote the proliferation, migration and neovascularization of HRMECs under high-glucose conditions.

Comparative study of widefield swept-source optical coherence tomography angiography in eyes with concomitant age-related macular degeneration and diabetic retinopathy

BACKGROUND/AIMS

We sought to evaluate widefield swept-source optical coherence tomography angiography (WF SS-OCTA) among eyes with concomitant age-related macular degeneration (AMD) and diabetes mellitus or diabetic retinopathy (DM/DR).

METHODS

This cross-sectional, comparative study consisted of three study groups: eyes with (1) AMD and DM/DR, (2) AMD alone and (3) DM/DR alone. WF SS-OCTA (3×3, 6×6 and 12×12 mm) images were captured. Vascular metrics included foveal avascular zone (FAZ), vessel density (VD) and vessel skeletonised density (VSD). Mixed-effects multivariable regression models adjusted for age were performed by cohort and subgroup based on AMD and DR stages.

RESULTS

Our cohort included 287 eyes from 186 patients with an average age of 64±14.0 years old. Results revealed significantly reduced vascular metrics in concomitant AMD and DM/DR eyes (N=68) compared with AMD-only eyes (N=71) on all angiograms but not compared with DM/DR-only eyes (N=148). For example, when compared with AMD-only eyes, AMD and DM/DR eyes had significantly reduced VD (β=-0.03, p=0.016) and VSD (β=-1.09, p=0.022) on 12×12 mm angiograms, increased FAZ perimeter (β=0.51, p=0.025) and FAZ area (β=0.11, p=0.015) on 6×6 mm angiogram, and reductions in all VD and VSD metrics on 3×3 and 6×6 mm angiograms. However, only 3×3 mm angiogram FAZ metrics were significantly different when comparing DM/DR eyes with concomitant AMD and DM/DR eyes.

CONCLUSION

WF SS-OCTA revealed significant reductions in retinal microvasculature metrics in AMD and DM/DR eyes compared with AMD-only eyes but not compared with DM/DR-only eyes.

Protective Effects of Bioactive Compound-Derived Nanoparticle Against Diabetic Retinopathy Through the Modulation of the NF-κB Signaling Pathway

Diabetic retinopathy is a prevalent and severe microvascular complication of diabetes, often causing visual impairment and blindness in adults. This condition significantly impacts the quality of life for many diabetes patients worldwide. Berberine (BBR), a bioactive compound known for its effects on blood glucose levels, has shown promise in managing diabetic complications. However, the exact mechanism of how BBR influences the development of diabetic retinopathy remains unclear. In this study, we focused on synthesizing a formulation derived from BBR and assessing its protective effects against diabetic retinopathy. The formulation was created using a green synthesis method and thoroughly characterized. In vitro studies demonstrated the antioxidant activity of the formulation against 2,2-diphenyl-1-picryl-hydrazyl-hydrate. We also examined the NF-κB signaling pathway at a molecular level using real-time polymerase chain reaction. To mimic diabetic retinopathy in a controlled setting, a diabetic rat model was established through streptozotocin injection. The rats were divided into normal, diabetic, and treatment groups. The treatment group received the formulated treatment via intragastric administration for several weeks, while the other groups received normal saline. Evaluation of histopathological characteristics and microstructural changes in the retina using hematoxylin and eosin staining revealed that the bioactive compound-derived nanoparticle exhibited favorable biological, chemical, and physical properties. Treatment with the formulation effectively reduced oxidative stress induced by diabetes and inhibited the NF-κB signaling pathway in the diabetic rat model. Under high glucose conditions, oxidative stress was heightened, leading to mitochondria-dependent cell apoptosis in Müller cells via the activation of the NF-κB signaling pathway. The bioactive compound-derived formulation counteracted these effects by decreasing IκB phosphorylation, preventing NF-κB nuclear translocation, and deactivating the NF-κB signaling pathway. Furthermore, treatment with the bioactive compound-derived formulation mitigated retinal micro- and ultrastructural changes associated with diabetic retinopathy. These results indicate that the formulation protects against diabetic retinopathy by suppressing oxidative stress, reducing cell apoptosis, and deactivating the NF-κB signaling pathway. This suggests that the bioactive compound-derived formulation could be a promising therapeutic option for diabetic retinopathy.

Risk factors affecting the utilization of eye care services evaluated by the CDC's behavior risk factor surveillance system from 2018 to 2021

When thinking about major health concerns in the U.S. and around the world, eye care ranks lower compared to cardiovascular disease, cancer, and diabetes. However, people do not think about the direct connection between diabetes and eye health. Untreated diabetes can lead to visual impairments such as blindness or difficulty seeing. Studies have found that eye health associated with nutrition, occupational exposure, diabetes, high blood pressure, and heart disease are some of the known risk factors. This study aimed to identify the potential risk factors that are associated with visual impairment (VI). The data used for this analysis were obtained from the Centers for Disease Control and Prevention (CDC) - Behavioral Risk Factor Surveillance System (BRFSS) from 2018 to 2021. We found important characteristics, such as the U.S. region, general health perception, employment status, income status, age, and health insurance source, that are associated with VI. Our study confirmed that the common demographical factors including age, race/ethnicity, the U.S. region, and gender are associated with VI. The study also highlights associations with additional risk factors such as health insurance source, general health perceptions, employment status, and income status. Using this information, we can reach out to communities with large numbers of individuals experiencing vision challenges and help educate them on prevention and treatment protocols, thereby effectively addressing VI and blindness challenges within our communities, neighborhoods, and finally, the broader society.

Aging in Ocular Blood Vessels: Molecular Insights and the Role of Oxidative Stress

Acknowledged as a significant pathogenetic driver for numerous diseases, aging has become a focal point in addressing the profound changes associated with increasing human life expectancy, posing a critical concern for global public health. Emerging evidence suggests that factors influencing vascular aging extend their impact to choroidal and retinal blood vessels. The objective of this work is to provide a comprehensive overview of the impact of vascular aging on ocular blood vessels and related diseases. Additionally, this study aims to illuminate molecular insights contributing to vascular cell aging, with a particular emphasis on the choroid and retina. Moreover, innovative molecular targets operating within the domain of ocular vascular aging are presented and discussed.

Optical coherence tomography as a potential surrogate marker of dopaminergic modulation across the life span

The retina has been considered a "window to the brain" and shares similar innervation by the dopaminergic system with the cortex in terms of an unequal distribution of D1 and D2 receptors. Here, we provide a comprehensive overview that Optical Coherence Tomography (OCT), a non-invasive imaging technique, which provides an "in vivo" representation of the retina, shows promise to be used as a surrogate marker of dopaminergic neuromodulation in cognition. Overall, most evidence supports reduced retinal thickness in individuals with dopaminergic dysregulation (e.g., patients with Parkinson's Disease, non-demented older adults) and with poor cognitive functioning. By using the theoretical framework of metacontrol, we derive hypotheses that retinal thinning associated to decreased dopamine (DA) levels affecting D1 families, might lead to a decrease in the signal-to-noise ratio (SNR) affecting cognitive persistence (depending on D1-modulated DA activity) but not cognitive flexibility (depending on D2-modulated DA activity). We argue that the use of OCT parameters might not only be an insightful for cognitive neuroscience research, but also a potentially effective tool for individualized medicine with a focus on cognition. As our society progressively ages in the forthcoming years and decades, the preservation of cognitive abilities and promoting healthy aging will hold of crucial significance. OCT has the potential to function as a swift, non-invasive, and economical method for promptly recognizing individuals with a heightened vulnerability to cognitive deterioration throughout all stages of life.

Microglia-endothelial cross-talk regulates diabetes-induced retinal vascular dysfunction through remodeling inflammatory microenvironment

Inflammation-mediated crosstalk between neuroglial cells and endothelial cells (ECs) is a fundamental feature of many vascular diseases. Nevertheless, the landscape of inflammatory processes during diabetes-induced microvascular dysfunction remains elusive. Here, we applied single-cell RNA sequencing to elucidate the transcriptional landscape of diabetic retinopathy (DR). The transcriptome characteristics of microglia and ECs revealed two microglial subpopulations and three EC populations. Exploration of intercellular crosstalk between microglia and ECs showed that diabetes-induced interactions mainly participated in the inflammatory response and vessel development, with colony-stimulating factor 1 (CSF1) and CSF1 receptor (CSF1R) playing important roles in early cell differentiation. Clinically, we found that CSF1/CSF1R crosstalk dysregulation was associated with proliferative DR. Mechanistically, ECs secrete CSF1 and activate CSF1R endocytosis and the CSF1R phosphorylation-mediated MAPK signaling pathway, which elicits the differentiation of microglia and triggers the secretion of inflammatory factors, and subsequently foster angiogenesis by remodeling the inflammatory microenvironment through a positive feedback mechanism.

Association Between VEGF-460C/T Gene Polymorphism and Risk of Diabetic Retinopathy in Type 2 Diabetes Mellitus: A Meta-Analysis

The aim of the study was to investigate the relationship between VEGF-460C/T polymorphism and susceptibility to diabetic retinopathy (DR) in type 2 diabetes mellitus (T2DM) by meta-analysis. A comprehensive search was conducted across six databases until September 2023 to identify studies examining the association between VEGF-460C/T polymorphism and susceptibility to DR. Data process was performed by Stata 15.0 software. Eight studies were included, involving 1463 patients with DR. In the overall analysis, the difference was statistically significant only in the homozygous model (CC vs. TT: OR=1.86, p=0.048). A subgroup analysis of 6 papers with genotype frequency satisfying HWE in the control group indicated significant differences among the allele (C vs. T: OR=1.34, p=0.037), recessive (CC vs. CT+TT: OR=1.96, p=0.022) and homozygous (CC vs. TT: OR=2.28, p=0.015) models. However, in the dominant and heterozygous models, the difference was not statistically significant. The sensitivity of the HWE-based subgroup analysis showed that the conclusions in other gene models except the heterozygote model were not robust. This meta-analysis indicated that VEGF-460C/T gene polymorphism is associated with susceptibility to DR in T2DM. Allele C and genotype CC at the VEGF-460C/T locus are associated with an increased risk of DR in T2DM. However, considering that the results are not robust, more trials involving more rigorous design are needed to verify the findings of this review in the future.

Interplay of endothelial-mesenchymal transition, inflammation, and autophagy in proliferative diabetic retinopathy pathogenesis

Background

Assessment and validation of endothelial-mesenchymal transition (EndoMT) in the retinal endothelium of patients with proliferative diabetic retinopathy (PDR) at the level of retinal and vitreous specimens, and preliminary discussion of its regulatory mechanisms.

Methods

Transcriptome sequencing profiles of CD31+ cells from 9 retinal fibrovascular mem-branes (FVMs) and 4 postmortem retinas were downloaded from GEO databases to analyze EndoMT-related differentially expressed genes (DEGs). Then, 42 PDR patients and 34 idiopathic macular holes (IMH) patients were enrolled as the PDR and control groups, respectively. Vitreous humor (VH) samples were collected, and the expression of EndoMT-related proteins was quantified by enzyme-linked immunosorbent assay.

Results

A total of 5845 DEGs were identified, and we subsequently focused on the analysis of 24 EndoMT-related marker genes, including the trigger of EndoMT, endothelial genes, mesenchymal genes, transcription factors, inflammatory factors, and autophagy markers. Six of these genes were selected for protein assay validation in VH, showing increased mesenchymal marker (type I collagen α 2 chain, COL1A2) and decreased endothelial marker (VE-cadherin, CDH5) accompanied by increased TGFβ, IL-1β, LC3B and P62 in PDR patients. In addition, anti-VEGF therapy could enhance EndoMT-related phenotypes.

Conclusions

EndoMT may underlie the pathogenesis of PDR, and the induction and regulation correlate with autophagy defects and the inflammatory response.

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.

Ferroptosis in the ageing retina: A malevolent fire of diabetic retinopathy

Ageing retina is prone to ferroptosis due to the iron accumulation and impaired efficiency of intracellular antioxidant defense system. Ferroptosis acts as a cell death modality that is characterized by the iron-dependent accumulation of lipid peroxidation. Ferroptosis is distinctively different from other types of regulated cell death (RCD) at the morphological, biochemical, and genetic levels. Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Its prevalence and severity increase progressively with age. Recent reports have shown that ferroptosis is implicated in the pathophysiology of DR. Under hyperglycemia condition, the endothelial cell and retinal pigment epithelium (RPE) cell will undergo ferroptosis, which contributes to the increased vascular permeability and the disrupted blood retinal barrier (BRB). The underlying etiology of DR can be attributed to the impaired BRB integrity and subsequent damages of the neurovascular units. In the absence of timely intervention, the compromised BRB can ultimately cause profound visual impairments. In particular, the ageing retina is vulnerable to ferroptosis, and hyperglycemia will accelerate the progression of this pathological process. In this article, we discuss the contributory role of ferroptosis in DR pathogenesis, and summarize recent therapeutic trials that targeting the ferroptosis. Further study on the ferroptosis mediated damage would enrich our knowledge of DR pathology, and promote the development of clinical treatment for this degenerative retinopathy.

Impact of aging on vascular ion channels: perspectives and knowledge gaps across major organ systems

Individuals aged ≥65 yr will comprise ∼20% of the global population by 2030. Cardiovascular disease remains the leading cause of death in the world with age-related endothelial "dysfunction" as a key risk factor. As an organ in and of itself, vascular endothelium courses throughout the mammalian body to coordinate blood flow to all other organs and tissues (e.g., brain, heart, lung, skeletal muscle, gut, kidney, skin) in accord with metabolic demand. In turn, emerging evidence demonstrates that vascular aging and its comorbidities (e.g., neurodegeneration, diabetes, hypertension, kidney disease, heart failure, and cancer) are "channelopathies" in large part. With an emphasis on distinct functional traits and common arrangements across major organs systems, the present literature review encompasses regulation of vascular ion channels that underlie blood flow control throughout the body. The regulation of myoendothelial coupling and local versus conducted signaling are discussed with new perspectives for aging and the development of chronic diseases. Although equipped with an awareness of knowledge gaps in the vascular aging field, a section has been included to encompass general feasibility, role of biological sex, and additional conceptual and experimental considerations (e.g., cell regression and proliferation, gene profile analyses). The ultimate goal is for the reader to see and understand major points of deterioration in vascular function while gaining the ability to think of potential mechanistic and therapeutic strategies to sustain organ perfusion and whole body health with aging.

Orbital blood vessels changes on color duplex imaging in diabetics with and without diabetic retinopathy

To compare changes in ophthalmic artery (OA) and its branches in diabetics with and without diabetic retinopathy (DR) using color duplex imaging (CDI), and to correlate these changes with the disease variables. 60 eyes of 60 diabetic patients were enrolled, divided into 3 groups: without DR (Group A), with Non-Proliferative DR (Group B) and with Proliferative DR (PDR) (Group C). Laboratory testing including HbA1c was done. Patients underwent CDI, by which OA, Central Retinal Artery (CRA) and Ciliary Arteries were identified; for each of them we measured Peak systolic velocity (PSV), End Diastolic velocity (EDV) and Resistivity Index (RI). Results were compared to clinical, laboratory and fundus examination. OA EDV was significantly lower and OA RI was found to be significantly higher in Group C (p = 0.027 and 0.025 respectively). CRA PSV and EDV were significantly lower in Group C (p = 0.017 and 0.001 respectively). PCA RI was significantly higher in Group C (p = 0.008). HbA1c was negatively correlated with CRA PSV (p = 0.041), also it was negatively correlated with CRA EDV (p = 0.0001), as well as with PCA EDV (p = 0.002). There was direct significant correlation between HbA1c and PCA RI (p = 0.012). Duration since diagnosis was negatively correlated with CRA EDV (p = 0.004). Multivariate linear regression showed that DR is an independent predictor for low OA EDV, high OA RI, low CRA EDV and high PCA RI. DR is an independent risk factor for orbital and ocular vessels flow alteration, thus can be used as a prognostic tool in diabetic patients. CDI can be reliably used in diabetics to predict early changes or progression of DR.

Factors associated with glycemic control and diabetes complications in a group of Saudi patients with type 2 diabetes

Poor glycemic control is a risk factor for micro and macrovascular complications of diabetes. The aim of this study was to assess the prevalence and factors related to suboptimal glycemic control and diabetes complications in a group of patients with type 2 diabetes mellitus (T2DM). This cross-sectional descriptive study conducted in Al Qassim region, Saudi Arabia. Two hundred patients with T2DM were enrolled. Demographic, social, and self-care behavior data were collected. A thorough clinical evaluation was done. Glycated hemoglobin, lipid, and kidney profile results were recorded. Mann-Whitney test was used to compare different groups. For comparing categorical data, Chi-square (χ2) test was performed. Multivariate logistic regression analyses used to detect predictors of poor glycemic control and macrovascular and microvascular complications. The median age of patients was 58 years, and 62% of them were males. Only 22.5% of patients had glycated hemoglobin <7%. Forty-four patients (22%) had evidence of macrovascular complications. Retinopathy, neuropathy, and nephropathy were found in 42.5%, 32.5%, and 12%, respectively. Longer diabetes duration was significantly associated with poor glycemic control (OR = 1.006, P < .005). The age of the patients was independently associated with macrovascular complications (OR = 1.050, P = .029). Hyperlipidemia was significantly associated with neuropathy (OR = 0.229, P = .043) and retinopathy (OR = 12.887, P = .003). Although physical activity was lower in patients with suboptimal glycemic levels (P = .024), cardiovascular disease (P = .030), neuropathy (P < .001), retinopathy (P < .001), and nephropathy (P = .019), multivariate analysis showed that it was only independently associated with neuropathy (OR = 0.614, P = .001). The prevalence of suboptimal glycemic control is high in the studied population. Effective health measures are urgently needed to stop diabetes complications, especially retinopathy and neuropathy. Elderly people with long durations of diabetes, and lower physical activity should be the focus of the interventions. Tailored exercise programs are particularly needed for better diabetes control and for the prevention of complications in patients with T2DM.

Effects of autophagy inhibitor 3-methyladenine on a diabetic mice model

AIM

To investigate the role of autophagy inhibitor 3-methyladenine (3-MA) on a diabetic mice model (DM) and the potential mechanism.

METHODS

Male C57BL/6J mice were randomly divided into a normal control group (NC group) and an DM group. DM were induced by multiple low-dose intraperitoneal injection of streptozotocin (STZ) 60 mg/kg·d for 5 consecutive days. DM mice were randomly subdivided into untreated group (DM group), 3-MA (10 mg/kg·d by gavage) treated group (DM+3-MA group) and chloroquine (CQ; 50 mg/kg by intraperitoneal injection) treated group (DM+CQ group). The fasting blood glucose (FBG) levels were recorded every week. At the end of experiment, retinal samples were collected. The expression levels of pro-apoptotic proteins cleaved caspase-3, cleaved poly ADP-ribose polymerase 1 (PARP1) and Bax, anti-apoptotic protein Bcl-2, fibrosis-associated proteins Fibronectin and type 1 collagen α1 chain (COL1A1), vascular endothelial growth factor (VEGF), inflammatory factors interleukin (IL)-1β and tumor necrosis factor (TNF)-α, as well as autophagy related proteins LC3, Beclin-1 and P62 were determined by Western blotting. The oxidative stress indicators 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA) were detected by commercial kits.

RESULTS

Both 3-MA and CQ had short-term hypoglycemic effect on FBG and reduced the expression of VEGF and inflammatory factors IL-1β and TNF-α in DM mice. 3-MA also significantly alleviated oxidative stress indicators 8-OHdG and MDA, decreased the expression of fibrosis-related proteins Fibronectin and COL1A1, pro-apoptotic proteins cleaved caspase-3, cleaved PARP1, as well as the ratio of Bax/Bcl-2. CQ had no significant impact on the oxidative stress indicators, fibrosis, and apoptosis related proteins. The results of Western blotting for autophagy related proteins showed that the ratio of LC3 II/LC3 I and the expression of Beclin-1 in the retina of DM mice were decreased by 3-MA treatment, and the expression of P62 was further increased by CQ treatment.

CONCLUSION

3-MA has anti-apoptotic and anti-fibrotic effects on the retina of DM mice, and can attenuate retinal oxidative stress, VEGF expression and the production of inflammatory factors in the retina of DM mice. The underlying mechanism of the above effects of 3-MA may be related to its inhibition of early autophagy and hypoglycemic effect.

Genipin relieves diabetic retinopathy by down-regulation of advanced glycation end products via the mitochondrial metabolism related signaling pathway

BACKGROUND

Glycation is an important step in aging and oxidative stress, which can lead to endothelial dysfunction and cause severe damage to the eyes or kidneys of diabetics. Inhibition of the formation of advanced glycation end products (AGEs) and their cell toxicity can be a useful therapeutic strategy in the prevention of diabetic retinopathy (DR). Gardenia jasminoides Ellis (GJE) fruit is a selective inhibitor of AGEs. Genipin is an active compound of GJE fruit, which can be employed to treat diabetes.

AIM

To confirm the effect of genipin, a vital component of GJE fruit, in preventing human retinal microvascular endothelial cells (hRMECs) from AGEs damage in DR, to investigate the effect of genipin in the down-regulation of AGEs expression, and to explore the role of the CHGA/UCP2/glucose transporter 1 (GLUT1) signal pathway in this process.

METHODS

In vitro, cell viability was tested to determine the effects of different doses of glucose and genipin in hRMECs. Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry, immunofluorescence, wound healing assay, transwell assay, and tube-forming assay were used to detect the effect of genipin on hRMECs cultured in high glucose conditions. In vivo, streptozotocin (STZ) induced mice were used, and genipin was administered by intraocular injection (IOI). To explore the effect and mechanism of genipin in diabetic-induced retinal dysfunction, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) assays were performed to explore energy metabolism and oxidative stress damage in high glucose-induced hRMECs and STZ mouse retinas. Immunofluorescence and Western blot were used to investigate the expression of inflammatory cytokines [vascular endothelial growth factor (VEGF), SCG3, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-18, and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing 3 (NLRP3)]. The protein expression of the receptor of AGEs (RAGE) and the mitochondria-related signal molecules CHGA, GLUT1, and UCP2 in high glucose-induced hRMECs and STZ mouse retinas were measured and compared with the genipin-treated group.

RESULTS

The results of CCK-8 and colony formation assay showed that genipin promoted cell viability in high glucose (30 mmol/L D-Glucose)-induced hRMECs, especially at a 0.4 μmol/L dose for 7 d. Flow cytometry results showed that high glucose can increase apoptosis rate by 30%, and genipin alleviated cell apoptosis in AGEs-induced hRMECs. A high glucose environment promoted ATP, ROS, MMP, and 2-NBDG levels, while genipin inhibited these phenotypic abnormalities in AGEs-induced hRMECs. Furthermore, genipin remarkably reduced the levels of the pro-inflammatory cytokines TNF-α, IL-1β, IL-18, and NLRP3 and impeded the expression of VEGF and SCG3 in AGEs-damaged hRMECs. These results showed that genipin can reverse high glucose induced damage with regard to cell proliferation and apoptosis in vitro, while reducing energy metabolism, oxidative stress, and inflammatory injury caused by high glucose. In addition, ROS levels and glucose uptake levels were higher in the retina from the untreated eye than in the genipin-treated eye of STZ mice. The expression of inflammatory cytokines and pathway protein in the untreated eye compared with the genipin-treated eye was significantly increased, as measured by Western blot. These results showed that IOI of genipin reduced the expression of CHGA, UCP2, and GLUT1, maintained the retinal structure, and decreased ROS, glucose uptake, and inflammation levels in vivo. In addition, we found that SCG3 expression might have a higher sensitivity in DR than VEGF as a diagnostic marker at the protein level.

CONCLUSION

Our study suggested that genipin ameliorates AGEs-induced hRMECs proliferation, apoptosis, energy metabolism, oxidative stress, and inflammatory injury, partially via the CHGA/UCP2/GLUT1 pathway. Control of advanced glycation by IOI of genipin may represent a strategy to prevent severe retinopathy and vision loss.

Revisiting Retinal Degeneration Hallmarks: Insights from Molecular Markers and Therapy Perspectives

Visual impairment and blindness are a growing public health problem as they reduce the life quality of millions of people. The management and treatment of these diseases represent scientific and therapeutic challenges because different cellular and molecular actors involved in the pathophysiology are still being identified. Visual system components, particularly retinal cells, are extremely sensitive to genetic or metabolic alterations, and immune responses activated by local insults contribute to biological events, culminating in vision loss and irreversible blindness. Several ocular diseases are linked to retinal cell loss, and some of them, such as retinitis pigmentosa, age-related macular degeneration, glaucoma, and diabetic retinopathy, are characterized by pathophysiological hallmarks that represent possibilities to study and develop novel treatments for retinal cell degeneration. Here, we present a compilation of revisited information on retinal degeneration, including pathophysiological and molecular features and biochemical hallmarks, and possible research directions for novel treatments to assist as a guide for innovative research. The knowledge expansion upon the mechanistic bases of the pathobiology of eye diseases, including information on complex interactions of genetic predisposition, chronic inflammation, and environmental and aging-related factors, will prompt the identification of new therapeutic strategies.

The extracellular matrix mechanics in the vasculature

Mechanical stimuli from the extracellular matrix (ECM) modulate vascular differentiation, morphogenesis and dysfunction of the vasculature. With innovation in measurements, we can better characterize vascular microenvironment mechanics in health and disease. Recent advances in material sciences and stem cell biology enable us to accurately recapitulate the complex and dynamic ECM mechanical microenvironment for in vitro studies. These biomimetic approaches help us understand the signaling pathways in disease pathologies, identify therapeutic targets, build tissue replacement and activate tissue regeneration. This Review analyzes how ECM mechanics regulate vascular homeostasis and dysfunction. We highlight approaches to examine ECM mechanics at tissue and cellular levels, focusing on how mechanical interactions between cells and the ECM regulate vascular phenotype, especially under certain pathological conditions. Finally, we explore the development of biomaterials to emulate, measure and alter the physical microenvironment of pathological ECM to understand cell-ECM mechanical interactions toward the development of therapeutics.

Screening for Patients with Visual Acuity Loss in Primary Health Care: A Cross Sectional Study in a Deprived Hungarian Population

Screening for visual acuity loss (VAL) is not applied systematically because of uncertain recommendations based on observations from affordable countries. Our study aimed to evaluate the effectiveness of primary health care-based screening. A cross-sectional investigation was carried out among adults who did not wear glasses and did not visit an ophthalmologist in a year (N = 2070). The risk factor role of sociodemographic factors and the cardiometabolic status for hidden VAL was determined by multivariable linear regression models. The prevalence of unknown VAL of at least 0.5 was 3.7% and 9.1% in adults and in the above-65 population. Female sex (b = 1.27, 95% CI: 0.35; 2.18), age (b = 0.15, 0.12; 0.19), and Roma ethnicity (b = 2.60, 95% CI: 1.22; 3.97) were significant risk factors. Higher than primary school (b_{secondaryschoolwithoutgraduation} = -2.06, 95% CI: -3.64; -0.47; and b_{secondaryschoolwithgraduation} = -2.08, 95% CI: -3.65; -0.51), employment (b = -1.33, 95% CI: -2.25; 0.40), and properly treated diabetes mellitus (b = -2.84, 95% CI: -5.08; -0.60) were protective factors. Above 65 years, female sex (b = 3.85, 95% CI: 0.50; 7.20), age (b = 0.39, 95% CI: 0.10; 0.67), Roma ethnicity (b = 24.79, 95% CI: 13.83; 35.76), and untreated diabetes (b = 7.30, 95% CI: 1.29; 13.31) were associated with VAL. Considering the huge differences between the health care and the population's social status of the recommendation-establishing countries and Hungary which represent non-high-income countries, the uncertain recommendation of VAL screening should not discourage general practitioners from organizing population-based screening for VAL in non-affordable populations.

Serum cholinesterase is associated with incident diabetic retinopathy: the Shanghai Nicheng cohort study

BACKGROUND

Serum cholinesterase (ChE) is positively associated with incident diabetes and dyslipidemia. We aimed to investigate the relationship between ChE and the incidence of diabetic retinopathy (DR).

METHODS

Based on a community-based cohort study followed for 4.6 years, 1133 participants aged 55-70 years with diabetes were analyzed. Fundus photographs were taken for each eye at both baseline and follow-up investigations. The presence and severity of DR were categorized into no DR, mild non-proliferative DR (NPDR), and referable DR (moderate NPDR or worse). Binary and multinomial logistic regression models were used to estimate the risk ratio (RR) and 95% confidence interval (CI) between ChE and DR.

RESULTS

Among the 1133 participants, 72 (6.4%) cases of DR occurred. The multivariable binary logistic regression showed that the highest tertile of ChE (≥ 422 U/L) was associated with a 2.01-fold higher risk of incident DR (RR 2.01, 95%CI 1.01-4.00; P for trend < 0.05) than the lowest tertile (< 354 U/L). The multivariable binary and multinomial logistic regression showed that the risk of DR increased by 41% (RR 1.41, 95%CI 1.05-1.90), and the risk of incident referable DR was almost 2-fold higher than no DR (RR 1.99, 95%CI 1.24-3.18) with per 1-SD increase of log_e-transformed ChE. Furthermore, multiplicative interactions were found between ChE and elderly participants (aged 60 and older; P for interaction = 0.003) and men (P for interaction = 0.044) on the risk of DR.

CONCLUSIONS

In this study, ChE was associated with the incidence of DR, especially referable DR. ChE was a potential biomarker for predicting the incident DR.

PDLIM1 inhibits cell migration and invasion in diabetic retinopathy via negatively regulating Wnt3a

The injury of vascular endothelial cells is a crucial factor in the development of diabetic retinopathy (DR). PDLIM1 (a member of the PDZ and LIM protein family) has been reported to exert an essential function in vascular diseases. This study aimed to elucidate the role of PDLIM1 on retinal vascular endothelial cells in DR. Immunofluorescence staining was used to localize the expression of PDLIM1 in the mouse retina. In some tumor diseases, PDLIM1 has been reported to play a key role in regulating the Wnt pathway. However, no in-depth reports have been found in DR. Retinal capillary endothelial cells (RCECs) were treated with high-glucose and high-lipid (HG/HL) culture medium, and siRNA transfection to investigate the role of PDLIM1 in DR. PDLIM1 and Wnt3a expression was confirmed by qRT-PCR and western blotting. Flow cytometry, Transwell assay, and scratch assay were used to test the ability of cell apoptosis, migration, and invasion. PDLIM1 was mainly expressed in the retinal pigment epithelium (RPE), ganglion cell layer (GCL), inner plexus layer (IPL), and outer plexus layer (OPL). HG/HL increased Wnt3a levels and promoted cell's ability of apoptosis, migration, and invasion, which were reversed by the knockdown of PDLIM1. PDLIM1 was found to play a protective role in diabetic retinopathy by counter-regulating Wnt3a. PDLIM1 ameliorates cell apoptosis, migration, and invasion by negatively regulating Wnt3a in RCECs of DR, which suggests that PDLIM1 might be a promising therapeutic target for DR treatment.

Innate immunity dysregulation in aging eye and therapeutic interventions

The prevalence of eye diseases increases considerably with age, resulting in significant vision impairment. Although the pathobiology of age-related eye diseases has been studied extensively, the contribution of immune-related changes due to aging remains elusive. In the eye, tissue-resident cells and infiltrating immune cells regulate innate responses during injury or infection. But due to aging, these cells lose their protective functions and acquire pathological phenotypes. Thus, dysregulated ocular innate immunity in the elderly increases the susceptibility and severity of eye diseases. Herein, we emphasize the impact of aging on the ocular innate immune system in the pathogenesis of infectious and non-infectious eye diseases. We discuss the role of age-related alterations in cellular metabolism, epigenetics, and cellular senescence as mechanisms underlying altered innate immune functions. Finally, we describe approaches to restore protective innate immune functions in the aging eye. Overall, the review summarizes our current understanding of innate immune functions in eye diseases and their dysregulation during aging.

Traditional Chinese Medicine Injections for Diabetic Retinopathy: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: The aim of this study was to compare the efficacy of different injected Traditional Chinese Medicines in the treatment of diabetic retinopathy (DR) and to provide a reference for the selection of adjuvant therapy for DR. Content: Related literature in multiple biological databases and websites was searched up to April 15, 2022, without language and publication time restrictions. A Bayesian network meta-analysis was used to analyze the included studies. Summary: Compared with conventional treatment, the combined use of injected Traditional Chinese Medicines, including astragalus, danhong, Ginkgo biloba extract powder, ginkgo leaf extract and dipyridamole (GLED), ligustrazine (LIG), mailuoning, puerarin, safflower, shuxuetong, safflower yellow sodium chloride, and xueshuantong (XST), can significantly improve the clinical effectiveness in patients with DR, while LIG, XST, and GLED can improve vision. The strength of the evidence ranged from high to very low. Outlook: In patients with DR, the combination of multiple injected Traditional Chinese Medicines is more effective than conventional treatment; some of these medicines may also improve visual acuity. This study may provide a good resource and reference for the selection of adjuvant therapy for DR.

Hotspots and trends in ophthalmology in recent 5 years: Bibliometric analysis in 2017–2021

Purpose

The purpose of this study was to investigate the hotspots and research trends of ophthalmology research.

Method

Ophthalmology research literature published between 2017 and 2021 was obtained in the Web of Science Core Collection database. The bibliometric analysis and network visualization were performed with the VOSviewer and CiteSpace. Publication-related information, including publication volume, citation counts, countries, journals, keywords, subject categories, and publication time, was analyzed.

Results

A total of 10,469 included ophthalmology publications had been cited a total of 7,995 times during the past 5 years. The top countries and journals for the number of publications were the United States and the Ophthalmology. The top 25 global high-impact documents had been identified using the citation ranking. Keyword co-occurrence analysis showed that the hotspots in ophthalmology research were epidemiological characteristics and treatment modalities of ocular diseases, artificial intelligence and fundus imaging technology, COVID-19-related telemedicine, and screening and prevention of ocular diseases. Keyword burst analysis revealed that “neural network,” “pharmacokinetics,” “geographic atrophy,” “implementation,” “variability,” “adverse events,” “automated detection,” and “retinal images” were the research trends of research in the field of ophthalmology through 2021. The analysis of the subject categories demonstrated the close cooperation relationships that existed between different subject categories, and collaborations with non-ophthalmology-related subject categories were increasing over time in the field of ophthalmology research.

Conclusions

The hotspots in ophthalmology research were epidemiology, prevention, screening, and treatment of ocular diseases, as well as artificial intelligence and fundus imaging technology and telemedicine. Research trends in ophthalmology research were artificial intelligence, drug development, and fundus diseases. Knowledge from non-ophthalmology fields is likely to be more involved in ophthalmology research.

Diabetic Retinopathy May Covariate With Stroke in Diabetes Mellitus

Diabetes mellitus is a chronic metabolic disorder with increasing prevalence per hour. Cataracts are one of the most common eye complications, and they affect all structures of the eye. The incidence of cataracts is increasing in patients with diabetes by several mechanisms. With the advancement of technology, cataract surgery is now a necessary procedure for diabetic patients. High-risk complications, like diabetic macular oedema, diabetic retinopathy (DR), phakic, postoperative cyst, and postoperative macular oedema, and macular oedema and endophthalmitis following surgery for a pseudocyst, could result in blindness. The importance of preoperative, intraoperative, and postoperative factors cannot be overestimated in managing complications and improving visual outcomes. DR can be a severe problem if it worsens and causes non-proliferative or proliferative DR or if fluid accumulation in the eye is diagnosed as macular oedema. A woman progressing to sight-threatening DR during childbearing age experiences distress and often requires ocular treatment. Diabetes that has been present for a more extended period, as well as more significant hyperglycaemia, hypertension, cardiovascular diseases, and elevated blood pressure, substantially predict the development of DR. Oxidative stress can be caused by hyperglycaemia, irregular metabolic processes, and people with DR developing neurodegeneration. Therefore, controlling postprandial hyperglycaemia is crucial for preventing DR. Femtosecond laser technology, multifocal intraocular lenses, and other surgical innovations are popularly referred to as surgical management; it will be engaged in the coming era to determine whether there will be a continued reduction in the complication of cataract surgery. This article aims to review the correlation of DR with stroke and its screening and to outline the critical management strategies. 

Diabetic retinopathy: Involved cells, biomarkers, and treatments

Diabetic retinopathy (DR), a leading cause of vision loss and blindness worldwide, is caused by retinal neurovascular unit dysfunction, and its cellular pathology involves at least nine kinds of retinal cells, including photoreceptors, horizontal and bipolar cells, amacrine cells, retinal ganglion cells, glial cells (Müller cells, astrocytes, and microglia), endothelial cells, pericytes, and retinal pigment epithelial cells. Its mechanism is complicated and involves loss of cells, inflammatory factor production, neovascularization, and BRB impairment. However, the mechanism has not been completely elucidated. Drug treatment for DR has been gradually advancing recently. Research on potential drug targets relies upon clear information on pathogenesis and effective biomarkers. Therefore, we reviewed the recent literature on the cellular pathology and the diagnostic and prognostic biomarkers of DR in terms of blood, protein, and clinical and preclinical drug therapy (including synthesized molecules and natural molecules). This review may provide a theoretical basis for further DR research.

Risk Factors of Microvascular Complications Among Type 2 Diabetic Patients Using Cox Proportional Hazards Models: A Cohort Study in Tabuk Saudi Arabia

Purpose

The burden of type 2 diabetes (T2D) is high in Saudi Arabia, but data related to its complications are limited. This study aimed to determine the incidence of microvascular complications caused by T2D and evaluate the impact of the associated risk factors.

Patients and Methods

This retrospective cohort study was conducted at two military hospitals in Tabuk, Saudi Arabia. Data on the socio-demographics, glycaemic profile, blood lipid indices, duration of T2D, and associated microvascular complications were collected from electronic health records and medical files. Descriptive statistics and Cox proportional hazards models were used for data analysis.

Results

This study included 1563 T2D patients. The incidence of microvascular complications was 34.3% (95% confidence interval [CI], 32.0-36.6). Retinopathy was the most common complication (incidence=20.0%; 95% CI, 18.0-22.0%), while nephropathy was the least common complication (incidence=12.2%; 95% CI, 10.6-13.8%). Advanced age (≥65 years) showed the highest risk of retinopathy (Hazard ratios [HR], 2.86; 95% CI, 2.56-3.21), neuropathy (HR, 2.70; 95% CI, 2.40-3.05), and nephropathy (HR, 2.37; 95% CI, 2.12-2.64) compared with their counterparts. After adjusting for potential confounders, the study found that the significant risk factors for microvascular complications were longer duration (≥10 years) of T2D (HR, 5.3; 95% CI, 5.1-5.6), uncontrolled hypertension (HR, 3.9; 95% CI, 3.3-4.2), poor glycaemic control (HR, 4.6; 95% CI, 4.3-5.1), obesity (HR, 2.3; 95% CI, 2.2-2.6), and dyslipidaemia (HR, 1.6; 95% CI, 1.2-2.0).

Conclusion

Given the high burden of microvascular complications in military healthcare facilities in Tabuk, Saudi Arabia, a context-specific accessible public health program focusing on the promotion of a healthy lifestyle, physical activity, and consumption of a healthy diet, as well as the early diagnosis and management of diabetes, needs to be developed and implemented.

The Association Between Diabetic Retinopathy and the Prevalence of Age-Related Macular Degeneration—The Kailuan Eye Study

This study aimed to investigate the prevalence of age-related macular degeneration (AMD) in patients with diabetes mellitus (DM) and diabetic retinopathy (DR) and analyze whether DR is a risk factor for AMD. This population-based epidemiological study included 14,440 people from the Kailuan Eye Study in 2016, of whom 1,618 were patients with type 2 DM aged over 50 years, and 409 had DM with DR. We analyzed whether there were differences in the prevalence of AMD between DM with DR and DM without DR, and conducted a hierarchical statistical analysis according to different stages of DR. Using variable regression analysis, we explored whether DR constituted a risk factor for AMD. In the DM population, the prevalence of wet AMD in patients with DM with and without DR was 0. 3 and 0.2%, respectively, with no significant difference (P = 0.607). Meanwhile, the prevalence of dry AMD in patients with DM with and without DR was 20.8 and 16.0%, respectively, with a significant difference. In the subgroup analysis of dry AMD, the prevalence of early, middle, and late dry AMD in DM with DR was 14.4, 5.9, and 0.5%, respectively. In DM without DR, the prevalence of early, middle, and late dry AMD was 10.5, 4.8, and 0.7%, respectively (P = 0.031). In the subgroup analysis of DR staging, statistical analysis could not be performed because of the limited number of patients with PDR. In the variable regression analysis of risk factors for dry AMD, after adjusting for age, sex, body mass index, hypertension, and dyslipidemia, DR constituted the risk factor for dry AMD. In conclusion, DM did not constitute a risk factor for AMD, and the prevalence of wet AMD and dry AMD in patients with DM and DR was higher than that in patients with DM without DR (among which dry AMD was statistically significant). Multivariate regression analysis confirmed that DR is an independent risk factor for dry AMD. Reasonable control of DM and slowing down the occurrence and development of DR may effectively reduce the prevalence of AMD in patients with DM.

Mechanistic Pathogenesis of Endothelial Dysfunction in Diabetic Nephropathy and Retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are microvascular complications of diabetes. Microvascular endothelial cells are thought to be the major targets of hyperglycemic injury. In diabetic microvasculature, the intracellular hyperglycemia causes damages to the vascular endothelium, via multiple pathophysiological process consist of inflammation, endothelial cell crosstalk with podocytes/pericytes and exosomes. In addition, DN and DR diseases development are involved in several critical regulators including the cell adhesion molecules (CAMs), the vascular endothelial growth factor (VEGF) family and the Notch signal. The present review attempts to gain a deeper understanding of the pathogenesis complexities underlying the endothelial dysfunction in diabetes diabetic and retinopathy, contributing to the development of new mechanistic therapeutic strategies against diabetes-induced microvascular endothelial dysfunction.

Dapagliflozin protects neural and vascular dysfunction of the retina in diabetes

INTRODUCTION

Dapagliflozin, a sodium-glucose transporter inhibitor, effectively reduces blood glucose and is indicated for individuals with kidney diseases and cardiovascular disorders. In this study, we further expand the therapeutic benefit of dapagliflozin in the neural and vascular retina, with the potential to effectively manage diabetic retinopathy (DR), the most common complication of diabetes.

RESEARCH DESIGN AND METHODS

Db/db mice, an animal model of type 2 diabetes, were treated with dapagliflozin orally, and the electroretinogram (ERG) response and acellular capillary numbers were assessed. Messenger RNA levels of inflammatory cytokines were studied using real-time quantitative (q)PCR. We assessed endothelial cell migration in a scratch wound assay and retinal glucose uptake using human retinal endothelial cells.

RESULTS

The dapagliflozin treatment improved the ERG b-wave amplitude and decreased acellular capillary numbers. The scratch wound assay demonstrated a reduction in wound closure after dapagliflozin treatment. Retinal glucose uptake reduced after dapagliflozin treatment compared with the respective controls.

CONCLUSIONS

Our studies suggest that dapagliflozin treatment effectively corrects neural and vascular dysfunction of the retina in diabetes. This effect is mediated by a decrease in inflammation and improved glycemic control. In addition, dapagliflozin exhibits decreased wound healing and glucose uptake, which could benefit the retina. Thus, dapagliflozin could be helpful in the management of DR, with multimodal therapeutic effects.

A Novel Approach for Identification of Biomakers in Diabetic Retinopathy Recognition

In the emergence of anti-Antivascular endothelial growth factor (VEGF) drugs such as ranibizumab and bevacizumab, it has become obvious that the presence of outer retinal and subretinal fluid is the primary signal of the need for anti-VEGF therapy, and used to identify disease activity and assist diabetic retinopathy treatment. Despite advancements in diabetic retinopathy (DR) treatments, early detection is critical for DR management and remains a significant barrier. Clinical DR can be distinguished from non proliferative DR without visible vision loss and vision-threatening consequences such as macular edoema and proliferative retinopathy by retinal alterations in diabetes. The proposed method aggrandize the process of accurate detection of biomakers responsible for higher risk of diabetic retinopathy development in color fundus images. Furthermore, the proposed approach could be employed to quantify these lesions and their distributions efficientively as evident in the experimentation results.

miRNA, lncRNA and circRNA: Targeted Molecules Full of Therapeutic Prospects in the Development of Diabetic Retinopathy

Diabetic retinopathy (DR) is a common diabetic complication and the main cause of blindness worldwide, which seriously affects the quality of life of patients. Studies have shown that noncoding RNA (ncRNA) has distinct differentiated expression in DR and plays an important role in the occurrence and development of DR. ncRNAs represented by microRNAs (miRNAs), lncRNAs (lncRNAs), and circRNAs (circRNAs) have been shown to be widely involved in the regulation of gene expression and affect multiple biological processes of retinopathy. This article will review three RNAs related to the occurrence and development of DR on the basis of previous studies (especially their effects on retinal microangiopathy, retinal pigment epithelial cells, and retinal nerve cells) and discuss their underlying mechanisms and connections. Overall, this review will help us better understand the role of ncRNAs in the occurrence and development of DR and provide ideas for exploring potential therapeutic directions and targets.