Global Prevalence of Diabetic Retinopathy and Projection of Burden through 2045: Systematic Review and Meta-analysis

Immunotherapy with low-dose IL-2 attenuates vascular injury in mice with diabetic and neovascular retinopathy by restoring the balance between Foxp3+ Tregs and CD8+ T cells

AIMS/HYPOTHESIS

Diabetic retinopathy features damage to the retinal microvasculature that causes vessels to leak and proliferate and can lead to vision loss and blindness. Inflammation contributes to the development of diabetic retinopathy, but little is known about the role of the adaptive immune system, including the benefits of augmenting the Forkhead box protein P3 (Foxp3) regulatory T cell (Treg) compartment. We aimed to determine whether treatment with low-dose IL-2 expands and activates Tregs and reduces CD8+ T cells in the retina, and attenuates retinal inflammation and vasculopathy in murine models of diabetic retinopathy and neovascular retinopathy.

METHODS

Mouse models of streptozocin-induced diabetes and oxygen-induced retinopathy (OIR) were administered low-dose IL-2 (25,000 U) or vehicle (sterile water) by i.p. injection. Reporter mice expressing Foxp3 as a red fluorescent protein (RFP) conjugate or CD8 as a green fluorescent protein (GFP) conjugate were used to evaluate Foxp3+ Tregs and CD8+ T cells, respectively, in blood, lymphoid organs and retina using flow cytometry or confocal microscopy. Vasculopathy and the expression of angiogenic and inflammatory factors were assessed in the retina.

RESULTS

Low-dose IL-2 significantly expanded CD4+CD25+Foxp3+ Tregs in the blood and spleen of mouse models of OIR and diabetes (1.4- to 1.9-fold increase, p<0.01). This expansion enhanced Treg functionality, increasing the expression of cytotoxic T-lymphocyte-associated protein4 (CTLA4), programmed cell death protein1 (PD1) and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), and increased the ratio of Tregs to CD8+ T cells. This was accompanied in the retina by a twofold increase in Foxp3+ Tregs (diabetes: 3.01 ± 0.41 vs 5.90 ± 1.25 cells per field, p<0.001; OIR: 4.41 ± 1.48 vs 10.05 ± 2.91 cells per field, p<0.001) and a reduction in CD8+ T cells (diabetes: 4.65 ± 0.58 vs 3.00 ± 0.81 cells per field, p<0.01; OIR: 5.51 ± 1.33 vs 3.17 ± 1.14 cells per field, p<0.01). Low-dose IL-2 reduced the levels of the potent inflammatory factors intercellular adhesion protein1 and TNF and the chemokine IFNγ-inducible protein10 (IP-10) in the retina. Importantly, low-dose IL-2 treatment effectively attenuated retinal vasculopathy, with marked reductions in acellular capillaries (diabetes: 0.48-fold decrease, p<0.001), neovascularisation (OIR: 0.68-fold decrease, p<0.01) and vascular leakage, and expression of vascular endothelial growth factor.

CONCLUSIONS/INTERPRETATION

This study highlights the therapeutic potential of low-dose IL-2 to reduce retinal inflammation and severe vascular injury by boosting Tregs and reducing CD8+ T cells and inflammatory factors.

Correlation of point-wise retinal sensitivity with localized features of diabetic macular edema using deep learning

OBJECTIVE

To evaluate the association between localized features of diabetic macular edema (DME) and point-wise retinal sensitivity (RS) assessed with microperimetry (MP) using deep learning (DL)-based automated quantification on optical coherence tomography (OCT) scans.

DESIGN

Cross-sectional study.

PARTICIPANTS

Twenty eyes of 20 subjects with clinically significant DME were included in this study.

METHODS

Patients with DME visible on OCT scans (Spectralis Heidelberg Retina Angiograph [HRA]+OCT) completed 2 MP examinations using a custom 45 stimuli grid on MAIA (CenterVue). MP stimuli were coregistered with the corresponding OCT location using image registration algorithms. DL-based algorithms were used to quantify intraretinal fluid (IRF) and ellipsoid zone (EZ) thickness. Hard exudates (HEs) were quantified semiautomatically. Multivariable mixed-effect models were calculated to investigate the association between DME-specific OCT features and point-wise RS. As EZ thickness values below HEs were excluded, the models included either EZ thickness or HEs.

RESULTS

A total of 1800 MP stimuli from 20 eyes of 20 patients were analyzed. Stimuli with IRF (n = 568) showed significantly decreased RS compared to areas without (estimate [95% CI]: -1.11 dB [-1.69, -0.52]; p = 0.0002). IRF volume was significantly negatively (-0.45 dB/nL [-0.71; -0.18]; p = 0.001) and EZ thickness positively (0.14 dB/µm [0.1; 0.19]; p < 0.0001) associated with localized point-wise RS. In the multivariable mixed model, including HE volume instead of EZ thickness, a negative impact on RS was observed (-0.43/0.1 nL [-0.81; -0.05]; p = 0.027).

CONCLUSIONS

DME-specific features, as analyzed on OCT, have a significant impact on point-wise RS. IRF and HE volume showed a negative and EZ thickness, a positive association with localized RS.

Plasma metabolomic profiling of diabetic macular edema

Diabetic macular edema (DME), a sight-threatening retinopathy, is a leading cause of vision loss in persons with diabetes mellitus. Despite strict control of systemic risk factors, a fraction of patients with diabetes developed DME, suggesting the existence of other potential pathogenic factors underlying DME. This study aimed to investigate the plasma metabotype of patients with DME and to identify novel metabolite markers for DME. Biomarkers identified from this study will provide scientific insight and new strategies for the early diagnosis and intervention of DME. To match clinical parameters between case and control subjects, patients with DME (DME, n = 30) or those with diabetes but without DME (Control, n = 30) were assigned to the present case-control study. Distinct metabolite profiles of serum were examined using liquid chromatography-mass spectrometry (LC-MS). A total of 190 distinct metabolites between DME and Control groups were identified (VIP > 1, Fold Change > 1.5 or < 0.667, and P < 0.05). The distinct metabolites between DME and Control groups were enriched in 4 KEGG pathways, namely, Glutamate Metabolism, Carnitine Synthesis, Oxidation of Branched Chain Fatty Acids, and Phytanic Acid Peroxisomal Oxidation. Finally, 4 metabolites were selected as candidate biomarkers for DME, namely, 5-Phospho-beta-D-ribosylamine, Succinic acid, Ascorbyl glucoside, and Glutathione disulfide. The area under the curve for these biomarkers were 0.693, 0.772, 0.762, and 0.771, respectively. This study suggested that impairment in the metabolism and 4 potential metabolites were identified as metabolic dysregulation associated with DME, which might provide insights into potential new pathogenic pathways for DME. 5-Phospho-beta-D-ribosylamine was first identified as a novel metabolite marker, with no previous reports linking it to diabetes or DME. This discovery may offer valuable insights into potential new pathogenic pathways associated with DME.

A case-control prospective study to unravel zinc alpha 2 glycoprotein role in the pathophysiology of diabetic retinopathy

BACKGROUND AND OBJECTIVES

Diabetic retinopathy (DR) is a leading neurovascular complication affecting the working age group worldwide. Zinc alpha-2-glycoprotein (ZAG) is indeed an important adipokine, and it has been found to play a role in various metabolic conditions, including diabetes, metabolic syndrome and responses to lifestyle changes. In this study, we have assessed the levels of ZAG in the aqueous and vitreous humour of DR cases as a marker for the disease. It's a case-control prospective study wherein 65 Proliferative Diabetic Retinopathy (PDR) patients in the age group of 50-60 years with type 2 diabetes mellitus and with no other ocular complications were included. The PDR cases were classified with Tractional Retinal Detachment (TRD) and Fibrovascular Proliferation (FVP). 15 Macular hole (MH) patients in the age group of 60-70 years with no history of diabetes were included as disease control subjects. The groups were evaluated for demographic variables, biochemical parameters, vitreous ZAG levels and biomarkers. Data between the groups were compared statistically.

RESULTS

A significant increase in ZAG protein levels was observed in both vitreous humour and aqueous humour of PDR cases compared to MH control. A positive correlation was observed between ZAG and various biomarkers like adiponectin, leptin, galectin-3, Vascular endothelial growth factor (VEGF), pentraxin-3 (PTX3) and tumour necrosis factor-alpha (TNF- alpha). Unconditional logistic regression analysis was conducted, and ZAG had 20.167 odds ratio (95% CI 3.927-103.576, P = 0.001).

CONCLUSION

The present study shows that ZAG is increased in the vitreous and aqueous humour of the PDR cases compared to the macular hole. It was also correlated with the already reported biomarkers. It could be a risk factor for the disease based on the odds ratio.

Associations of genetic factors with vascular diabetes complications: an umbrella review

Background

To comprehensively assess evidence from published systematic review and meta-analyses (SRMAs) on the genetics of vascular diabetes complications.

Methods

A systematic literature search conducted in Medline and Embase identified 63 non-overlapping SRMAs. We re-conducted meta-analyses to compare diabetes with and without complications using multiple genetic models; evaluated associations using Venice criteria and Bayesian false-discovery probability (BFDP); and graded as highly credible, credible, and not credible. We also contrasted highly credible and credible associations to recent genome-wide association studies (GWASs).

Results

Highly credible evidence was discovered for single nucleotide polymorphisms (SNPs) rs1024611 at MCP-1 gene and SNP rs3025039 at VEGF gene with diabetic retinopathy (DR) in type 2 diabetes; SNP rs2268388 at ACACB gene, insertion/deletion (Ins/Del) variant at ACE gene, SNP rs1801133 at MTHFR gene, and SNP rs7903146 at TCF7L2 gene with diabetic kidney disease (DKD) in type 2 diabetes; and SNP rs4880 at SOD2 gene with diabetic peripheral neuropathy (DPN) in type 1 diabetes. Combining type 1 and 2 diabetes, highly credible evidence was discovered for insertion/deletion variant at ACE gene, SNP rs759853 at AKR1B1 gene, SNP rs1044498 at ENPP1 gene and DKD, and SNP rs1617640 at EPO gene for the combined endpoint of DR and DKD. None of these associations was directly replicated in the latest GWASs for DR and DKD, however, another SNP, rs55853916 at TCF7L2 gene had been detected as a GWAS hit for DKD.

Conclusions

This umbrella review rigorously assessed evidence on the genetics of vascular diabetes complications, complemented findings in recent GWASs and yielded insight into the optimal selection of genetic models for the design of GWASs on vascular diabetes complications. Mechanistic or bioinformatic studies are warranted to further assess the role of these genes in the pathology of vascular diabetes complications and their potential as drug targets.

Registration

PROSPERO: CRD42022384423.

Impact of Selective Peroxisome Proliferator-Activated Receptor (PPAR)-α Modulators and Fibrates on Microvascular Disease: Is There Still Room?

PURPOSE OF REVIEW

This review examines the role of fibrates and the selective PPAR-alpha modulators (SPPARM-α), pemafibrate, in diabetic microvascular disease. It reviews their potential to mitigate residual risk in retinopathy, nephropathy, neuropathy and peripheral vascular disease.

RECENT FINDINGS

These pharmacotherapies, beyond their lipid-lowering effects, may exert anti-inflammatory, antioxidant, and endothelial-protective actions. Secondary analyses of large clinical trials supports their efficacy in slowing retinopathy progression, reducing albuminuria, and preventing minor amputations. Recent analyses suggest that pemafibrate offers an enhanced efficacy and safety profile compared to conventional fibrate and may lower the incidence of diabetic foot ulcers and gangrene. Fibrates and SPPARM-α agonists represent promising therapies to prevent diabetic microvascular complications. Their benefits in reducing microvascular damage support their broader adoption in clinical practice. However, additional dedicated randomized trials are essential to validate the efficacy of those agents in contemporary diabetes care era and to address the growing burden of diabetes-related microvascular complications.

Predicting diabetic retinopathy based on routine laboratory tests by machine learning algorithms

OBJECTIVES

This study aimed to identify risk factors for diabetic retinopathy (DR) and develop machine learning (ML)-based predictive models using routine laboratory data in patients with type 2 diabetes mellitus (T2DM).

METHODS

Clinical data from 4259 T2DM inpatients at Beijing Tongren Hospital were analyzed, divided into a model construction data set (N = 3936) and an external validation data set (N = 323). Using 39 optimal variables, a prediction model was constructed using the eXtreme Gradient Boosting (XGBoost) algorithm and compared with four other algorithms: support vector machine (SVM), gradient boosting decision tree (GBDT), neural network (NN), and logistic regression (LR). The Shapley Additive exPlanation (SHAP) method was employed to interpret the XGBoost model. External validation was performed to assess model performance.

RESULTS

DR was present in 47.69% (N = 1877) of T2DM patients in the model construction data set. Among the models tested, the XGBoost model performed best with an AUC of 0.831, accuracy of 0.757, sensitivity of 0.754, specificity of 0.759, and F1-score of 0.752. SHAP explained feature importance for XGBoost model and identified key risk factors for DR. External validation yielded an accuracy of 0.650 for the XGBoost model.

CONCLUSIONS

The XGBoost-based prediction model effectively assesses DR risk in T2DM patients using routine laboratory data, aiding clinicians in identifying high-risk individuals and guiding personalized management strategies, especially in medically underserved areas.

Sodium butyrate inhibits activation of ROS/NF-κB/NLRP3 signaling pathway and angiogenesis in human retinal microvascular endothelial cells

BACKGROUND

To determine the impact of sodium butyrate on the activation of the reactive oxygen species (ROS)/nuclear factor kappa B (NF-κB)/NLR family pyrin domain containing 3 (NLRP3) signaling pathway and angiogenesis in human retinal microvascular endothelial cells (HRMECs) caused by high glucose (HG).

METHODS

HRMECs were grown for 24 h or 72 h in HG solution (30 mmol/L D-glucose) with 5 mM NaB. Using Cell Counting Kit-8, the effects of HG and NaB levels on the viability of HRMECs were examined. Using various kits, intracellular ROS levels, lactate dehydrogenase (LDH), and Malondialdehyde (MDA) in cell supernatants were measured. Western blot, Immunofluorescence, and Real-time quantitative polymerase chain reaction were employed to quantify protein and messenger RNA expression. Using wound-healing and tube formation tests, the migratory proficiency and angiogenesis of HRMECs were evaluated.

RESULTS

NaB demonstrated a reduction in ROS production, as well as the release of LDH and MDA in HG-induced HRMECs. Additionally, NaB led to a decrease in protein expression of phosphorylation of NF-κB, NLRP3, Caspase 1, interleukin, vascular cell adhesion molecule-1 and intercellular adhesion molecule-1. The impact of HG on zonula occluden-1, a tight junction protein, was attenuated by NaB. Furthermore, NaB inhibited the migration and tube formation of HRMECs partly by ROS/NF-κB/NLRP3 pathway.

CONCLUSION

NaB suppresses the activation of ROS/NF-κB/NLRP3 signaling pathway and angiogenesis in HRMECs induced by HG.

Evolution of ophthalmological care in adult with diabetes in France between 2010 and 2022: a nationwide study

PURPOSE

The aim of this study is to describe ophthalmological care of adults with diabetes in France and its evolution between 2010 and 2022.

METHODS

In this study, we used the ESND, a representative permanent random sample of 2/100th of the entire French population. Ophthalmological care was defined by the combination of ophthalmological procedures (fundus examination, color fundus photography, Optical Coherence Tomography..) and/or ophthalmological treatment (intravitreal injection or laser treatment) during the year. Changes in annual rates during the study period were assessed using linear regression models excluding 2020.

RESULTS

From 2010 to 2022, the number of adults treated for diabetes in the ENSD increased from 48 329 patients (mean age 65.3 ± 13.0, 46.3% women) to 68 397 patients (mean age 67.0 ± 13.2, 44.8% women). Among them, the annual rate of ophthalmological care was stable (46.5% in 2010 and 48.5% in 2022) and the difference was not significant (β = 0.10% per year, p = 0.11). The yearly ophthalmological treatment rate increased significantly (3.3% in 2010 and 5.3% in 2022, β = 0.2% per year, p < 0.0001). Rates were lower during the COVID-19 outbreak in 2020.Women, individuals aged between 66-80 years, those living in the least deprived areas and those treated with combined insulin and non-insulin treatment had higher yearly ophthalmological care rate.

CONCLUSION

In this large nationwide representative study with recent and updated data, although ophthalmological treatment rate has increased over the decade mainly due to intravitreal injections, less than half of the diabetic patients receive yearly ophthalmological care.

Nighttime Systolic Blood Pressure a Major Factor of Retinal Vascular Caliber Changes in Patients With Newly Diagnosed Type 2 Diabetes Mellitus

BACKGROUND

Changes in retinal vessel caliber are crucial for detecting early retinopathy, a significant cause of blindness in individuals with Diabetes Mellitus type 2 (T2DM). This study aims to evaluate the changes in retinal vessel caliber and identify factors associated with these changes in recently diagnosed T2DM patients.

METHODS

The study included newly diagnosed T2DM patients (within 6 months of diagnosis) who were free of antidiabetic treatment (except metformin) and matched individuals based on age and blood pressure (BP). Data collected included somatometric measurements, BP (office and 24-h), hematological data, albuminuria (via 24-h urine collections), ten-year atherosclerotic cardiovascular disease risk (ASCVD score), endothelial dysfunction (measured by Asymmetric Dimethylarginine, ADMA), retinal microvascular changes, assessed as central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and arteriovenous ratio (AVR) using specialized software on nonmydriatic fundus photographs.

RESULTS

The study involved 87 T2DM patients and 90 controls, aged 57±11 years. Key findings include no significant differences in CRAE, CRVE, and AVR between T2DM patients and controls. Age (P=0.019) and nighttime systolic BP (SBP) (P=0.002) were independent predictors of AVR. CRAE was independently associated with nighttime SBP (P=0.048). CRVE was independently associated with age (P=0.016), dipping (P=0.002), and smoking (P=0.018). In normotensive subjects, AVR was significantly lower in T2DM patients (P=0.035).

CONCLUSIONS

The study concludes that increased nighttime SBP is a more critical factor than hyperglycemia in affecting retinal vascular caliber changes in newly diagnosed T2DM patients. This highlights the importance of managing nocturnal hypertension to prevent retinal damage in this patient population.

Incidence of diabetic retinopathy and its predictors among adult patients with diabetes in Ethiopia: a frailty model

Background

Diabetic retinopathy (DR) is becoming a more widespread public concern worldwide, leading to visual impairments. It has become the leading cause of blindness among working-age adults globally, despite established treatments that can reduce the risk by 60%.

Objective

This study aimed to determine the incidence of diabetic retinopathy and its predictors among adult patients with diabetes in public hospitals in Central and Southern Ethiopia.

Methods

A hospital-based follow-up study was conducted in selected public hospitals in Central and Southern Ethiopia. A total of 376 participants of newly diagnosed adult diabetes were enrolled from 2015-2023 and the follow-up the date was from date of enrolment to the development of events. The data were collected by reviewing their records and entered in Epi-data version 4.6.0.2 and exported to STATA version 14 for analysis. Descriptive statistics of the variables were obtained. The Weibull model with gamma frailty distribution was fitted. Bivariable and multivariable analyses were done, and variables with a p-value less than 0.05 and a corresponding 95% confidence interval in the final model were used. The model of adequacy was checked.

Results

376 adult diabetic patient records were reviewed with the mean baseline age (± standard deviation) of 34.8±10 years. The univariate frailty was statistically significant (Theta=0.236 (0.131, 0.496)). A total of 376 adult patients with diabetes were followed for 682.894 person-years. Overall, an incidence rate of 14.06/100 person-years. Proteinuria (AHR = 2.21: 95% CI: 1.45, 3.57), cardiovascular disease (AHR = 2.23: 95% CI: 1.34, 4.03), and type II DM (AHR = 2.87: 95% CI: 1.30, 6.13) were identified as significant predictors of diabetic retinopathy.

Conclusion

Overall incidence rate of diabetic retinopathy was high. The most effective way to protect our vision from diabetic retinopathy is to manage diabetes effectively and offer support to high-risk individuals with diabetes. Therefore, healthcare professionals and relevant health authorities should target on addressing these factors in their initiatives to prevent diabetic retinopathy in diabetic patients.

Performance and limitation of machine learning algorithms for diabetic retinopathy screening and its application in health management: a meta-analysis

BACKGROUND

In recent years, artificial intelligence and machine learning algorithms have been used more extensively to diagnose diabetic retinopathy and other diseases. Still, the effectiveness of these methods has not been thoroughly investigated. This study aimed to evaluate the performance and limitations of machine learning and deep learning algorithms in detecting diabetic retinopathy.

METHODS

This study was conducted based on the PRISMA checklist. We searched online databases, including PubMed, Scopus, and Google Scholar, for relevant articles up to September 30, 2023. After the title, abstract, and full-text screening, data extraction and quality assessment were done for the included studies. Finally, a meta-analysis was performed.

RESULTS

We included 76 studies with a total of 1,371,517 retinal images, of which 51 were used for meta-analysis. Our meta-analysis showed a significant sensitivity and specificity with a percentage of 90.54 (95%CI [90.42, 90.66], P < 0.001) and 78.33% (95%CI [78.21, 78.45], P < 0.001). However, the AUC (area under curvature) did not statistically differ across studies, but had a significant figure of 0.94 (95% CI [- 46.71, 48.60], P = 1).

CONCLUSIONS

Although machine learning and deep learning algorithms can properly diagnose diabetic retinopathy, their discriminating capacity is limited. However, they could simplify the diagnosing process. Further studies are required to improve algorithms.

Barriers to annual diabetic retinopathy screening and subsequent recommended follow-up adherence among Chinese diabetics: a cross-sectional and longitudinal study

OBJECTIVES

Adherence to routine annual eye evaluations for diabetes is frequently insufficient on a global scale. We evaluated the adherence to annual diabetic retinopathy screening (DRS) and recommended follow-up among Chinese patients with diabetes, and we also identified the associated risk variables.

DESIGN

This was a cross-sectional and longitudinal study.

SETTING

Patients with diabetes were inquired about their completion of DRS within the preceding year. All participants were required to complete the Compliance with Annual Diabetic Eye Exams Survey.

PARTICIPANTS

Participants with diabetes who initially sought eye examination from November 2021 to October 2023 at He Eye Specialist Hospital, Shenyang, China.

OUTCOME MEASURES

Logistic regression analyses defined the risk factors associated with poor compliance with the annual DRS and recommended follow-up.

RESULTS

There were 468 patients registered, with a mean age of 67.42±10.66 years. A total of 308 (65.8%) participants had DRS in the previous year. Rural residents (OR 1.704, 95% CI 1.019 to 2.850, p=0.042), vision-threatening diabetic retinopathy (VTDR) (OR 1.948, 95% CI 1.145 to 3.313, p=0.014), item 7 (over the past 4 weeks, I have felt blue, downhearted or depressed) (OR 0.624, 95% CI 0.401 to 0.971, p=0.037) and item 42 (I receive a reminder from my eye doctor's office when it is time to schedule an exam) (OR 0.618, 95% CI 0.387 to 0.989, p=0.045) were associated with non-adherence to annual DRS. The compliance with DRS improved to 80.9% in the second year after health education and reminders of follow-up. VTDR (OR 3.063, 95% CI 1.852 to 5.066, p<0.01) was found to be the risk factor for poor compliance with scheduled follow-up.

CONCLUSIONS

About one-third of diabetics did not complete annual DRS; that rate decreased to one-fifth after health education and follow-up reminders.

Advances in molecular epidemiology of diabetic retinopathy: from genomics to gut microbiomics

Diabetic retinopathy (DR) remains a prevalent complication of diabetes mellitus and a leading cause of blindness worldwide. The growing global diabetic population underscores the urgency to deepen our understanding of DR pathogenesis and develop effective prevention strategies. This review synthesizes recent advancements in molecular epidemiology, spanning genomics, epigenomics, transcriptomics, proteomics, metabolomics, and gut microbiomics, elucidating genetic underpinnings, epigenetic modifications, transcriptional alterations, protein biomarkers, metabolic disruptions, and gut microbiota dysbiosis associated with DR. Highlighted are key findings from genome-wide association studies (GWAS), Mendelian randomization (MR) studies, candidate gene association studies, and advancements in epigenetic mechanisms, revealing intricate disease pathways and potential therapeutic targets. Additionally, insights into altered metabolic profiles and gut microbiota compositions in DR underscore their emerging roles in disease progression and complications. Challenges and future directions in molecular epidemiological research are discussed to accelerate the translation of these findings into clinical applications for personalized DR management. The integration of multi-omics research findings may provide novel perspectives for facilitating rapid and accurate disease diagnosis, enabling dynamic disease monitoring, and advancing targeted therapeutic strategies.

Non-ocular biomarkers for early diagnosis of diabetic retinopathy by non-invasive methods

Diabetic retinopathy (DR) is the predominant vision-threatening complication in individuals with diabetes mellitus. Timely diagnosis and intervention facilitate the prevention of diabetes-associated visual impairment. Classical imaging methods may prevent the timely detection of DR due to shortages of specialized facilities and retinal specialists, particularly in remote areas. In recent years, research on biomarkers related to DR has rapidly developed, playing an important role in risk assessment and early detection of the disease. Some ocular biomarkers from the vitreous body or aqueous humor were invasive, which hampered their application in clinical practice. Meanwhile, biomarkers based on omics were limited by their uneasily accessible use and complicated variables with a relatively low degree of reproducibility. As modern technology progresses, advanced non-ocular biomarkers of DR have established a comprehensive platform for the prompt identification of DR, independent of ophthalmic professionals or devices and accessible to non-ophthalmologists during community screenings. This review focuses on biomarkers derived from non-ocular sample sources, such as nailfold and skin, accessible through non-invasive methods, to reveal if they can be considered as an effective option for the early identification of DR by non-ophthalmologists in community screening initiatives.

Blueberry Anthocyanin Extracts (BAEs) Protect Retinal and Retinal Pigment Epithelium Function from High-Glucose-Induced Apoptosis by Activating GLP-1R/Akt Signaling

Diabetic retinopathy is a severe diabetes complication leading to vision impairment and blindness primarily due to the disruption of insulin signaling in the retina. This study investigated the protective effects of blueberry anthocyanin extracts (BAEs) and its main component, anthocyanin-3-glucoside (C3G), in the retinas of diabetic mice and ARPE-19 cells under high-glucose (HG) conditions. The results showed that diabetic mice suffered significant weight loss, elevated glycemic levels, and increased retinal cell apoptosis after 10 weeks. Treatment with various doses of BAEs resulted in a significant reduction in glycemic levels, weight stabilization, decreased levels of inflammatory cytokines, and inhibition of retinal cell apoptosis. These findings suggested that BAEs possess hypoglycemic properties, potentially mitigating diabetes-induced retinal damage by modulating associated signaling pathways. Immunoblotting analysis revealed that persistent hyperglycemia impaired the Akt/GSK3β signaling pathway in diabetic mice, while high doses of BAEs significantly restored the function of these pathways and promoted GLP-1 release, enhancing GLP-1R expression in the retina and potentially mitigating retinal injury. Finally, studies on the effects of C3G on ARPE-19 cell models deficient in REDD1 under HG conditions showed that C3G protected cells from HG damage through the GLP-1R/Akt signaling pathway. In conclusion, this research provides valuable insights into the therapeutic potential of BAEs and C3G for managing diabetes-related ocular complications.

Role of Tau Protein Hyperphosphorylation in Diabetic Retinal Neurodegeneration

Diabetic retinal neurodegeneration (DRN) is an early manifestation of diabetic retinopathy (DR) characterized by neurodegeneration that precedes microvascular abnormalities in the retina. DRN is characterized by apoptosis of retinal ganglion cells (involves alterations in retinal ganglion cells [RGCs], photoreceptors, amacrine cells and bipolar cells and so on), reactive gliosis, and reduced retinal neuronal function. Tau, a microtubule-associated protein, is a key mediator of neurotoxicity in neurodegenerative diseases, with functions in phosphorylation-dependent microtubule assembly and stabilization, axonal transport, and neurite outgrowth. The hyperphosphorylated tau (p-tau) loses its ability to bind to microtubules and aggregates to form paired helical filaments (PHFs), which further form neurofibrillary tangles (NFTs), leading to abnormal cell scaffolding and cell death. Studies have shown that p-tau can cause degeneration of RGCs in DR, making tau pathology a new pathophysiological model for DR. Here, we review the mechanisms by which p-tau contribute to DRN, including insulin resistance or lack of insulin, mitochondrial damage such as mitophagy impairment, mitochondrial axonal transport defects, mitochondrial bioenergetics dysfunction, and impaired mitochondrial dynamics, Abeta toxicity, and inflammation. Therefore, this article proposes that tau protein hyperphosphorylation plays a crucial role in the pathogenesis of DRN and may serve as a novel therapeutic target for combating DRN.

Single-cell analysis identifies MKI67+ microglia as drivers of neovascularization in proliferative diabetic retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is among the primary causes of blindness in individuals with diabetes. Elevated lactate levels have been identified as a critical biomarker associated with the prognosis of PDR. While significant lactate accumulation has been observed in the vitreous fluid of PDR patients, the detailed pathways through which lactate impacts pathological neovascularization remain insufficiently elucidated.

METHODS

The study employed single-cell RNA sequencing (scRNA-seq) to identify and characterize lactate-associated cell type in PDR patients. Key gene expression profiles and molecular pathways associated with lactate metabolism were analyzed. In vitro experiments were conducted using microglial cell cultures treated with high-glucose conditions (50 mM) to assess the induction of lactate metabolism-related genes. Additionally, an oxygen-induced retinopathy (OIR) mouse model was used to evaluate the impact of abemaciclib, an FDA-approved proliferation inhibitor, on retinal neovascularization.

RESULTS

To the best of our knowledge, this investigation is the first to delineate a novel microglial subset, designated as MKI67+ microglia, distinguished by robust upregulation of genes implicated in lactate metabolic processes and proliferation, such as MKI67, PARK7 and LDHA, as well as a pronounced enrichment of glycolysis-associated molecular pathways. This unique cell type promotes angiogenesis by interacting with endothelial cells via secreted phosphoprotein 1 (SPP1)-Integrin alpha 4 (ITGA4) signaling. In vitro experiments have shown the use of 50 mM high glucose to simulate microglia in PDR environment and observe its promotion of vascular proliferation. In the in vivo OIR model, treatment with abemaciclib, a FDA-approved proliferation inhibitor, significantly reduced neovascularization.

CONCLUSION

The identification of MKI67+ microglia as a cell type strongly associated with lactate metabolism provides a novel perspective on the mechanisms underlying PDR onset. These findings expand our understanding of the cellular and metabolic dynamics in PDR, emphasizing potential implications for targeted therapeutic interventions.

Elevated Triglyceride-Glucose Index as a Risk Stratification Marker for Diabetic Retinopathy in Type 2 Diabetes Mellitus: The Influence of Glycemic Control

Background

Diabetic retinopathy (DR) is a common microvascular complication observed in people with type 2 diabetes mellitus (T2DM). The triglyceride-glucose (TyG) index, an indicator of insulin resistance, has an uncertain role in glycemic management in T2DM patients at risk for DR. This study aimed to evaluate the association between the TyG index and DR risk across different glycemic control status.

Methods

A total of 4,372 T2DM in-patients from Beijing Tongren Hospital (2013-2024) were included in this study. The patients were categorized into four groups based on TyG index quartiles (Q1-Q4). Participants were stratified by TyG index quartiles (Q1-Q4) and glycemic control status (HbA1c <7%, 7-9%, and >9%). Restricted cubic spline (RCS) analysis, logistic regression, and subgroup analyses were employed to explore the associations among the TyG index, glycemic control and DR risk.

Results

Overall, there were positive association of the TyG index and DR risk. The highest TyG Q4 was significantly associated with an increased risk of DR (odds ratio [OR]: 1.289; 95% confidence interval [CI]: 1.008-1.648, P<0.05), compared with the lowest TyG Q1. Significant interaction was observed between the TyG index and glycemic control (P for interaction <0.05). Notably, the association was strongest in patients with HbA1c >9%.

Conclusion

The relationship between high TyG index and DR risk was more pronounced in patients with HbA1c >9% group, indicating that TyG index may serve as a useful tool for making risk stratification on glycemic control in T2DM patients.

Short-Chain Fatty Acids and the Gut-Retina Connection: A Systematic Review

The interplay between gut microbiota and retinal health, known as the gut--retina axis, has gained increasing attention in recent years. Short-chain fatty acids (SCFAs), metabolites produced by gut microbiota, have been identified as key mediators of gut-retina communication. This systematic review explores the role of SCFAs in retinal health and their potential impact on the development and progression of retinal diseases, such as diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma. A literature search was conducted across multiple databases, including PubMed, Google Scholar, and Science Direct, to identify studies published between 2014 and December 2024. Studies were included if they investigated the effects of SCFAs on retinal structure, function, or disease pathogenesis in animal models or human subjects. The review included 10 original articles spanning both preclinical and clinical studies. Evidence suggests that SCFAs play a crucial role in maintaining retinal homeostasis through anti-inflammatory and neuroprotective mechanisms. Dysbiosis of the gut microbiota, leading to altered SCFA production, was associated with increased retinal inflammation, oxidative stress, and vascular dysfunction. Furthermore, reduced SCFA levels were linked to the progression of retinal diseases, such as diabetic retinopathy and age-related macular degeneration. Modulation of gut microbiota and SCFA levels through dietary interventions or probiotics may represent a novel therapeutic strategy for preventing or managing retinal diseases. Further research is needed to elucidate the precise molecular mechanisms underlying SCFA-mediated retinal protection and to evaluate the efficacy of targeted therapies in clinical settings.

Discovery and identification of semaphorin 4D as a bioindicator of high fracture incidence in type 2 diabetic mice with glucose control

INTRODUCTION

Bone fracture is increasing in patients with type 2 diabetes mellitus (T2DM) due to skeletal fragility. Most antidiabetics are expected to reduce the incidence of fracture in patients with T2DM, however the results are disappointing. Metformin and GLP-1 receptor agonists have a neutral or minor positive effect in reducing fractures.

OBJECTIVES

We aim to reveal the mechanism of fracture in patients with T2DM treated with metformin or exendin-4, explore the key regulators responsible for bone fragility in T2DM.

METHODS

Trabecular and cortical masses in mice with T2DM were analyzed using micro-computed tomography. Biomechanical strength of bone was determined according to three-point bending, and the expression of bone-associated factors was examined with enzyme-linked immunosorbent assays. Important proteins and miRNAs were identified using proteomics analysis and deep screening analysis. Lastly, immunoprecipitation-mass spectrometry and dual-luciferase reporter analysis were used to identify key molecular signals.

RESULTS

We found that sermaphorin 4D (Sema4D) is the key regulator of bone fragility in T2DM. Exendin-4 increased the biomechanical properties of bone by decreasing serum Sema4D levels, and metformin has little effect on Sema4D. Anti-sema4D treatment could improve bone strength in T2DM mice compared with metformin or exendin-4. The biomechanical properties of bone were comparable between anti-Sema 4D and the combination of metformin and exendin-4. Exendin-4 promoted osteogenesis of BMSCs by activating CRMP2 to reverse the effect of sema4D. Metformin increased miR-140-3p levels, which decreased plexin B1 expression in bone mesenchymal stem cells. Metformin increased the effect of exendin-4 with more GLP-1 receptor expression to increase the biomechanical strength of bone via miR-140-3p-STAT3-miR-3657 signaling.

CONCLUSION

Blood glucose level is not the major factor contributing to impairment in bone remodeling. Sema4D is responsible for the increase in the incidence of bone fractures in T2DM. Accordingly, we proposed an effective therapeutic strategy to eliminate the effect of sema4D.

FTO-mediated Nrf2 demethylation alleviates high glucose-induced oxidative stress and apoptosis in retinal pigment epithelial cells

BACKGROUND

N6-methyladenosine (m6A) modification contributes to the development of diabetic retinopathy (DR). This study aimed to reveal the role and downstream regulatory signaling of an m6A demethylase fat mass and obesity-associated gene (FTO) in high glucose-induced damage of retinal pigment epithelial cells.

METHODS AND RESULTS

By stimulating ARPE-19 cells with different concentrations of glucose (0 mM-50 mM), we observed that FTO expression was significantly downregulated, while m6A modification level was upregulated in a glucose concentration-dependent manner in ARPE-19 cells. Then, ARPE-19 cells were transfected with FTO knockdown or overexpression vector, and administrated with high glucose (25mM) to perform functional verification experiments. FTO overexpression recovered cell viability, inhibited cell apoptosis, elevated GSH/GSSG ratio, but reduced MDA and ROS levels in high glucose-induced cells, while FTO knockdown further exacerbated high glucose-triggered oxidative stress and apoptotic cell death. Additionally, FTO overexpression upregulated the expression of NF-E2-related factor 2 (Nrf2) and activated the antioxidant heme oxygenase 1 (HO-1) signal through m6A demethylation on Nrf2 in high glucose-treated ARPE-19 cells. Finally, we proved that knockdown of Nrf2 or HO-1 reversed the protective effects of FTO overexpression on high glucose-treated ARPE-19 cells.

CONCLUSION

Altogether, the study demonstrated that FTO ameliorates high glucose-triggered oxidative stress and cell apoptosis through activating the Nrf2/HO-1 signaling pathway in an m6A-dependent manner.

Diabetic Retinopathy (DR): Mechanisms, Current Therapies, and Emerging Strategies

Diabetic retinopathy (DR) is one of the most prevalent complications of diabetes, affecting nearly one-third of patients with diabetes mellitus and remaining a leading cause of blindness worldwide. Among the various diabetes-induced complications, DR is of particular importance due to its direct impact on vision and the irreversible damage to the retina. DR is characterized by multiple pathological processes, primarily a hyperglycemia-induced inflammatory response and oxidative stress. Current gold standard therapies, such as anti-VEGF injections and photocoagulation, have shown efficacy in slowing disease progression. However, challenges such as drug resistance, partial therapeutic responses, and the reliance on direct eye injections-which often result in low patient compliance-remain unresolved. This review provides a comprehensive overview of the underlying molecular mechanisms in DR, the current therapies, and their unmet needs for DR treatment. Additionally, emerging therapeutic strategies for improving DR treatment outcomes are discussed.

Cost-Effectiveness and Budget Impact Analysis of the Use of Faricimab in Diabetic Macular Edema and Neovascular Age-Related Macular Degeneration in Colombia

Background: Retinal diseases are major contributors to disability, significantly affecting patients' quality of life. Diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD) represent a significant disease and economic burden in Colombia. Assessing the economic evaluation of available treatments is essential for the efficient allocation of healthcare resources. Objective: To estimate the cost-effectiveness and budget impact of using faricimab for the treatment of patients with DME and nAMD within the Colombian health system. Methods: This study used a 25-year Markov cohort model to estimate the cost-effectiveness of faricimab vs aflibercept, ranibizumab, and brolucizumab. We used the methodological guidelines of the local health technology assessment agency for conducting the cost-effectiveness and budget impact analysis. Transition probabilities and injection frequencies were derived from the literature. Drug prices were retrieved from public local databases. Quality-adjusted life years (QALYs) were assessed. The potential patient population for the budget impact analysis was estimated based on disease prevalence and expert consultations. Results: Faricimab treat-and-extend (T&E) was dominant vs aflibercept T&E (+0.22 QALYs), ranibizumab T&E (+0.55 QALYs), and brolucizumab for 8 to 12 weeks (+0.06 QALYs) in DME, generating cost savings (in US dollars) of 3849 , 1375, and 2824 , r e s p e c t i v e l y . I n n A M D , f a r i c i m a b a l s o s h o w e d d o m i n a n c e v s a f l i b e r c e p t a s n e e d e d ( + 0.12 Q A L Y s ) , r a n i b i z u m a b a s n e e d e d ( + 0.05 Q A L Y s ) , a n d b r o l u c i z u m a b 8 t o 12 w e e k s ( + 0.12 Q A L Y s ) w i t h s a v i n g s i n ( U S ) 7223, 5792 , a n d 6798, respectively. Assuming an annual market share increase for faricimab of 15% for DME and 13% for nAMD, the Colombian Health System could save 144 m i l l i o n o v e r 3 y e a r s . O f t h e s e s a v i n g s , 122.7 million are attributed to drug costs and 21.3 m i l l i o n t o a d m i n i s t r a t i o n c o s t s ( U S 1 = Col$4325). Conclusion: Considering a willingness to pay threshold of $5988 per additional QALY, faricimab is a cost-effective alternative for both DME and nAMD for the Colombian healthcare system, showing dominance over other anti-vascular endothelial growth factor agents. Faricimab provides better health outcomes at lower costs vs other treatments.

C-reactive protein to high-density lipoprotein cholesterol ratio: an independent risk factor for diabetic retinopathy in type 2 diabetes patients

Background and objective

Diabetic retinopathy (DR) is associated with abnormal lipid metabolism and inflammation. However, a single lipid or inflammatory parameter cannot accurately predict the prognosis of DR independently, because it is prone to be affected by various confounding factors. This study aimed to explore the relationship between the inflammation-lipid indicator C-reactive protein (CRP)/high-density lipoprotein cholesterol (HDL-C) and DR occurrence in subjects with type 2 diabetes mellitus (T2DM).

Methods

This hospital-based retrospective study included 784 T2DM patients. Diabetic retinopathy was diagnosed by nonmydriatic fundus photography and/or fundus examination apparatus. T2DM patients were divided into non-DR and DR groups. Demographics variables, clinical history and serum biochemical indicators of the subjects were collected. We also calculated the CRP/HDL-C ratio. The association between the CRP/HDL-C and DR was assessed using multivariate logistic regression analyses.

Results

A total of 784 participants, 612 without DR and 172 with DR, were included in the final sample analysis. Compared with non-DR participants, the DR diagnostic group had significantly higher CRP/HDL-C (4.03 ± 1.67 vs. 2.66 ± 0.97; p < 0.001). Then, the patients were grouped based on the quartiles of CRP/HDL-C, there was a gradual increase in the prevalence of DR was noted in T2DM patients along with the increased quartile of the CRP/HDL-C ratio (Q1: 7.65%; Q2: 15.31%; Q3: 19.90%; Q4: 44.90%; p = 0.028). After adjustment for the impact of various covariates, the odds ratio (OR) of the third and fourth vs. the first quartile of CRP/HDL-C were 2.905 (95% confidence interval [CI]: 1.372 ~ 6.152, p = 0.005) and 9.938 (95% CI: 4.987 ~ 19.804, p < 0.001), respectively. Further, multivariate logistic regression model showed that the CRP/HDL-C ratio (OR 3.176, 95% CI: 1.280 ~ 7.877, p = 0.013) was identified as risk factor for DR. Moreover, the area under the curve (AUC) to evaluate the predictive value of CRP/HDL-C for the risk of DR occurrence was 0.752 (95% CI: 0.711 ~ 0.794).

Conclusion

The ratio of C-reactive protein (CRP) to high-density lipoprotein cholesterol (HDL-C) is associated with DR in patients with T2DM, and CRP/HDL-C may be an effective marker to help identify the risk of DR in patients with T2DM.

N6-methyladenosine (m6A) modification regulates HSPA1A and HSPA1B expression in Müller cells under high glucose stress

Müller cells (MCs) represent the major glial cells that are responsible for maintaining retinal homeostasis. In diabetic retinopathy, Müller cell activation occurs in the initial stages, playing a role in many pathological processes, such as neovascularization, neuronal dysfunction, and inflammatory retinal environment. As the most common RNA modification in eukaryotes, N6-methyladenosine (m6A) exerts dynamic and reversible control over cellular functions in the context of high glucose (HG) stress. Here, we performed combined m6A and RNA sequencing to elucidate the landscape of m6A modification in MCs under HG environmental stimuli. The potential functions of aberrant m6A peaks and differentially expressed genes were analyzed using bioinformatics analysis. Our findings indicate that m6A modification may regulate the expression of heat shock proteins (HSPs) 70 isoforms HSPA1A and HSPA1B, which are stress-inducible chaperones critical for cell survival under adverse conditions, including hyperglycemia. Modulating m6A modification may regulate critical gene expression and cellular functions of MCs under HG stress.

How to Improve Attendance for Diabetic Retinopathy Screening: Ideas and Perspectives From People With Type 2 Diabetes and Health-care Professionals

OBJECTIVES

Our aim in this study was to identify how to improve diabetic retinopathy screening from the perspectives of people with type 2 diabetes and health-care professionals and to elicit their thoughts on initiatives to increase attendance.

METHODS

A total of 38 semistructured interviews were conducted with people with type 2 diabetes (n=20), general practitioners (n=10), and ophthalmic staff (n=8). The interviews examined ideas for improving screening and elicited feedback on 3 initiatives: getting a fixed appointment; same-day screening; and outsourcing screening to general practice, including the use of artificial intelligence (AI). Data analysis was guided by content analysis approaches.

RESULTS

Ideas for improving screening were centred around reducing the inconvenience of attendance, making appointment scheduling easier, and improving health-care professionals' communication. Participants recognized the potential benefits of the initiatives but expressed important reservations to consider. Concerns included the following: that a fixed appointment would cause less active patient involvement and negatively affect attendance; that same-day screening may result in loss of patient-provider communication; that people with type 2 diabetes may be uneasy with having the screening performed outside the eye clinic; and that health-care professionals were concerned about the finances, validity, and examination quality associated with outsourcing screening and using AI.

CONCLUSIONS

Participants' thoughts on how to improve diabetic retinopathy screening should be seen as starting points for potential future interventions. Although outsourcing screening and the use of AI have gained traction, our study indicates that the target population has reservations that are important to consider in future development and implementation of such strategies.

Activation of megakaryocytic leukemia 1 in endothelial cells contributes to diabetic retinopathy in mice

AIMS

Diabetic retinopathy (DR) represents one of the most devastating sequences in patients with diabetes. Endothelial dysfunction is a key pathological feature of and contributing factor to DR. In the present study we investigated the role of megakaryocytic leukemia 1 (MKL1) in DR pathogenesis.

METHODS AND MATERIALS

DR was induced in mice by feeding with a high-fat diet (HFD). The Mkl1-Rosa26-KI mice were crossed to the Cdh5-CreERT2 mice to generate endothelial-specific MKL1 knock-in mice (MKL1EC-KI).

KEY FINDINGS

In cultured human primary retinal endothelial cells exposure to high glucose promoted nuclear translocation of MKL1 without altering its mRNA or protein expression. MKL1 knockdown ameliorated whereas MKL1 over-expression exacerbated high glucose induced impairment of endothelial barrier function. Compared to wild type littermates, MKL1EC-KI mice fed on HFD displayed worsened insulin resistance and accelerated DR pathogenesis. Consistently, administration of an MKL1 inhibitor CCG-1423 protected the mice from HFD feeding induced metabolic disorders and DR pathogenesis.

SIGNIFICANCE

Our data demonstrate that MKL1 may contribute to diabetic retinopathy by regulating endothelial behavior. Targeting MKL1 with small-molecule inhibitors can be considered as a therapeutic solution for the treatment of diabetic retinopathy.

The Exploration of Disturbance of Capillary and Photoreceptor Communication Networks in Diabetic Retinopathy Through Single-Cell RNA-Seq

This study investigates the differences in ligand-receptor interactions between the communication network of vascular endothelial cells (ECs) and photoreceptor cells (PRCs)in diabetic retinopathy (DR) the mechanism was verified by animal experiments. The GSE209872 data set, including retinal specimens from five Sprague-Dawley rats induced by streptozotocin, was obtained from Gene Expression Omnibus. CM and EC data were extracted individually for reclustering, functional enrichment and trajectory analyses. Cell communication analysis was conducted to investigate the altered signals and significant ligand-receptor interactions. Moreover, novel ligand-receptor interactions were validated using immunofluorescence staining using 2, 4 and 8 weeks DR model; DR was treated with AAV-shANGPTL4, and retinal function was detected by Haematoxylin and eosin staining (HE), TUNEL and ELISA. The expression of ligand-receptor in DR Retina was detected by qPCR and immunohistochemistry. Nine cell types were determined in DR. Cellular communication results revealed four signalling pathways, including PTN, MK, ANGPTL and CXCL, that were significantly changed in DR. Furthermore, 3 ligand-receptor pairs (Ptn-Ncl, Mkd-Ncl and Angptl4-Sdc4) were obviously upregulated between ECs and PRCs, the expression of which was verified via immunofluorescence in the DR model. After treatment with AAV-shANGPTL4, the retinal thickness and average density of RGCs were decreased (p < 0.05). TUNEL staining showed that knocking down ANGPTL4 reduced the apoptosis of DR (p < 0.05), and VEGF and IGF-1 expression were downregulated (p < 0.01). The expression of ligand-receptors also decreased in the DR Model (p < 0.01). The vascular ECs and PRCs demonstrate significant heterogeneities in DR. ANGPTL4 was a decreased ligand-receptor expression and improved retinal function as a potential therapeutic target against DR.

Endostatin in disease modulation: From cancer to beyond

Angiogenesis plays a pivotal role in various pathological conditions, making it a key target in therapeutic development. Anti-angiogenic therapies are gaining traction for their potential in treating a range of angiogenesis-dependent diseases. Among these, endogenous angiogenesis inhibitors, particularly endostatin, have garnered significant attention for their therapeutic potential. While extensively studied for its anti-angiogenic effects in cancer, endostatin also exhibits anti-atherosclerotic and anti-fibrotic properties, broadening its therapeutic scope. Despite the successful clinical use of recombinant human endostatin in China for nearly two decades, its broader therapeutic potential remains underexplored. Thus, this review delves into the multifaceted applications of endostatin, examining its role in ocular diseases, inflammation, reproductive disorders, and tumor angiogenesis. Furthermore, it provides a comprehensive overview of its emerging roles beyond angiogenesis, particularly in the context of atherosclerosis and fibroproliferative conditions.

Diabetic Retinopathy Screening Using Smartphone-Based Fundus Photography and Deep-Learning Artificial Intelligence in the Yucatan Peninsula: A Field Study

BACKGROUND

To compare the performance of Medios (offline) and EyeArt (online) artificial intelligence (AI) algorithms for detecting diabetic retinopathy (DR) on images captured using fundus-on-smartphone photography in a remote outreach field setting.

METHODS

In June, 2019 in the Yucatan Peninsula, 248 patients, many of whom had chronic visual impairment, were screened for DR using two portable Remidio fundus-on-phone cameras, and 2130 images obtained were analyzed, retrospectively, by Medios and EyeArt. Screening performance metrics also were determined retrospectively using masked image analysis combined with clinical examination results as the reference standard.

RESULTS

A total of 129 patients were determined to have some level of DR; 119 patients had no DR. Medios was capable of evaluating every patient with a sensitivity (95% confidence intervals [CIs]) of 94% (88%-97%) and specificity of 94% (88%-98%). Owing primarily to photographer error, EyeArt evaluated 156 patients with a sensitivity of 94% (86%-98%) and specificity of 86% (77%-93%). In a head-to-head comparison of 110 patients, the sensitivities of Medios and EyeArt were 99% (93%-100%) and 95% (87%-99%). The specificities for both were 88% (73%-97%).

CONCLUSIONS

Medios and EyeArt AI algorithms demonstrated high levels of sensitivity and specificity for detecting DR when applied in this real-world field setting. Both programs should be considered in remote, large-scale DR screening campaigns where immediate results are desirable, and in the case of EyeArt, online access is possible.

Long-Term Diabetic Retinopathy Treatment Using Silicon Nanoneedles

Sustained-release ocular drug delivery systems with minimal invasiveness are critical for managing eye diseases that cause blindness. An innovative platform is presented for painless and long-term sustained ocular drug delivery utilizing controllably biodegradable silicon nanoneedles (Si NNs) conjugated with bevacizumab (Bev) integrated into a tear-soluble subconjunctival patch. The biocompatible patch facilitates easy application in the subconjunctival area of the eye and rapid dissolution in less than one minute upon contact with the tear film in the sclera, eliminating the need for removal procedures. The Si NNs, fabricated with precise control over their degradation kinetics, enable sustained and controlled release of Bev into the ocular tissues. This platform offers enhanced patient comfort, reduced risk of complications, and prolonged therapeutic efficacy. In vivo studies using a rabbit model of retinal neovascularization (RNV), a clinically relevant proliferative diabetic retinopathy (PDR), demonstrate the platform's ability to reduce RNV by 85% over a year, with no observable side effects. These results highlight the potential of this drug delivery method to penetrate the sclera and releaseBev gradually, providing a promising alternative for long-term, controllable ocular therapy. This technology represents a significant advancement in painless, convenient, and effective treatment for eye diseases requiring sustained drug delivery.

Unveiling ferroptosis genes and inhibitors in diabetic retinopathy through single-cell analysis and docking simulations

Diabetic retinopathy (DR) is a common microvascular complication of diabetes and a leading cause of vision loss worldwide. Although several mechanisms have been implicated in the pathogenesis of DR, emerging evidence suggests a link between ferroptosis and DR. Unfortunately, the exact mechanism underlying this connection is not clear. Therefore, investigating the role of ferroptosis in diabetic retinopathy holds promise for advancing our understanding of this complex disease and developing innovative treatments. We have identified differentially expressed genes (DEGs) and differentially expressed marker genes (DEMGs) from open-source single-cell RNA sequencing datasets by using in depth in silico approach. Subsequently, ferroptosis-associated DEGs (FA-DEGs), ferroptosis-associated DEMGs (FA-DEMGs), and ferroptosis-associated Hub Genes (FAHGs) were identified. The FDA-approved drugs for our target proteins were also identified, and their ADMET properties were assessed. Molecular docking and simulation were utilized to explore the interaction stability of the compounds with the target proteins. Overall, we identified 63 FA-DEMGs that were significantly enriched in Peroxiredoxin activity, Ferroptosis, Mitophagy, and Autophagy. Further analysis predicted that PRDX1 and UBC are candidate target proteins. Molecular docking results showed that dexamethasone has a high binding affinity for both PRDX1 and UBC. Additionally, molecular dynamics simulations revealed that dexamethasone (which showed the best hit in the docking analysis) exhibited a 'stable effect' on both PRDX1 and UBC. To summarize, this study showed that PRDX1 and UBC could be suitable therapeutic targets for dexamethasone, which might be helpful in the advance of DR treatments in the future.

Clinical and imaging characteristics associated with foveal neovascularization in proliferative diabetic retinopathy

PURPOSE

To assess the prevalence of foveal neovascularization (FNV) and its associated clinical features in proliferative diabetic retinopathy (PDR) eyes.

METHODS

Cross-sectional observational study. Participants underwent ultra-widefield photography, optical coherence tomography (OCT), and swept-source OCT angiography (SS-OCTA). FNV was defined as a hyperreflective lesion breaching the internal limiting membrane and displaying flow signal on OCTA, within 1-mm of foveal avascular zone. Vascular metrics were obtained from the ARI Network portal. Ischemic index (ISI) and inner choroid flow deficit percentage were calculated using FIJI from 12 × 12 and 6 × 6-mm scans, respectively. Logistic regression models were used to compare eyes with and without FNV.

RESULTS

We included 249 eyes of 164 patients (age: 58 [50-65] years). FNV was identified in 20 eyes (8%). Univariate logistic regression revealed significant associations between FNV and younger age (p = 0.03), higher maximal HbA1c (p = 0.04), worse visual acuity (VA) (p = 0.01), presence of disorganization of retinal inner layers (DRIL) (p = 0.01), no macular posterior vitreous detachment (PVD) (p = 0.03), neovascularization elsewhere (NVE) and at the disc (NVD) (p = 0.01 and p = 0.001), and greater ISI (p = 0.04). In multivariable analysis, a significant association remained between FNV and worse VA (p = 0.04), NVD (p < 0.001), DRIL (p < 0.001), and absence of macular PVD (p = 0.01). No associations were found with SS-OCTA vascular metrics.

CONCLUSIONS

This study provides a comprehensive characterization of FNV in PDR. FNV was identified in 8% of our cohort, being more prevalent in younger patients with severe PDR, as evidenced by NVD and DRIL presence. The absence of macular PVD may explain its association with younger age.

KEY MESSAGES

What is known • Neovascularization at the fovea occurs rarely in proliferative diabetic retinopathy. • OCT and OCT-angiography can be used to evaluate foveal neovascularization, which may be associated with choroidal vascular abnormalities. What is new • Foveal neovascularization was seen in 8% of eyes with proliferative diabetic retinopathy in this cohort. • Risk factors for foveal neovascularization included younger age, absence of macular posterior vitreous detachment, presence of neovascularization of the disc, and presence of disorganization of retinal inner layers. • We did not identify an association between foveal neovascularization and choroidal perfusion abnormalities in this study.

Diabetic retinopathy features in lund MetS rats

The Lund MetS rat (BBDR.cg-Leprdb/db.cp/LundRj) is a novel animal model that has a congenic leptin receptor deficiency (LepR-/-) and males exhibit a variety of metabolic abnormalities mimicking the human metabolic syndrome, including hyperglycemia, dyslipidemia, severe obesity, and a type 2 diabetes-like condition from 14 weeks of age. However, whether Lund MetS rats (LM rats) develop diabetic retinopathy is still unknown. The purpose is to investigate the features of diabetic retinopathy in this model. In this study, male LM rats aged 15 and 30 weeks were analyzed for pathological retinal changes, including vasculopathy, inflammation, reactive gliosis, oxidative stress, and neurodegeneration features on the retinas by histological, immunohistochemical, and gene and protein expression analysis. Compared with the non-diabetic LM rats, diabetic LM rats, mainly at 30 weeks of age, had a decrease in retinal thickness and loss of retinal ganglion cells and photoreceptors, indicating retinal neurodegeneration. They also presented an increase in VEGF-A expression, Endra, Icam-1, Vcam-1, and Endrb vascular genes, and albumin suggesting neurovascular unit dysfunction. Furthermore, retinas presented reactive gliosis and infiltration of microglia, TNF-α-positive vessels and expressed elevated levels of inflammatory genes Tnf-α, IL-18 and IL-6, and oxidative stress markers Sod2 and 8-hydroxy-2-deoxyguanosine (8-OHdG). Our results suggest that diabetic LM rats reproduce the early neurodegenerative and altered neuro-vascular features that also occur in the human diabetic eye.

Associations Between Serum IL-17A, Renal Function and Diabetic Retinopathy in Type 2 Diabetes Mellitus: Evidence From a Chinese Han Population

BACKGROUND

Evidence suggested that IL-17A was associated with renal function in type 2 diabetes. We used ultra-sensitive measurement to detect the concentration of IL-17A in human peripheral blood and explored the association of IL-17A with diabetic kidney disease (DKD).

METHODS

We recruited 138 participants from the Shanghai Diabetes Institute Inpatient Database of Shanghai Jiao Tong University Affiliated Sixth People's Hospital. Eighty-four individuals diagnosed as DKD were cases, and 54 type 2 diabetes individuals without DKD or diabetic retinopathy (DR) were controls. The concentration of serum IL-17A was detected by the High Sensitivity Immunoassay Quantitative Kit. Data was analysed by SAS.

RESULTS

The concentration of serum IL-17A in our population ranged from 0.07 pg/mL to 2.96 pg/mL with the median of 0.502 pg/mL. Our results suggested that the level of serum IL-17A in DKD case group was higher than in the control (P unadjusted = 0.0496, P adjusted = 0.0298). And serum creatinine, eGFR, ACR were used as indicators of renal function. Serum creatinine and ACR were positive correlated with the level of serum IL-17A (P adjusted = 0.0148; P adjusted = 0.0369), while eGFR showed a negative correlation (P adjusted = 0.0167). Additionally, the level of serum IL-17A was also significantly higher in DR case group compared with the control group (p = 0.0224).

CONCLUSION

Serum IL-17A level is associated with renal function decline and diabetic retinopathy in patients with type 2 diabetes in a Chinese Han population. Our results suggested that IL-17A may be a potential biomarker of DKD and DR.

Population-based assessment of awareness of diabetes and diabetes related eye diseases in rural areas in Telangana, India - implications for eye health promotion

CLINICAL RELEVANCE

Understanding the awareness level of diabetes and diabetes-related eye diseases will help in developing better eye health education programmes and improve health-seeking behaviour in the community.

BACKGROUND

Diabetes and diabetes related eye diseases are increasing in numbers both in urban and rural areas in India. There are limited data on awareness of diabetes and diabetes-related eye disease in rural communities of India. This study reports on awareness of diabetes and diabetes-related eye diseases in people aged ≥40 years from two rural districts of Telangana, India.

METHODS

A structured questionnaire was used to determine the awareness of diabetes and diabetes-related eye diseases among participants aged ≥40 years in the Khammam and Warangal districts of Telangana, India. Social investigators visited the participant's households and conducted the interviews. A positive response to a question on having heard about diabetes was considered as 'awareness'. For those aware, follow-up questions were asked about the effect of diabetes on vision, frequency of eye examination and source of information. A positive response on a question that diabetes could cause loss of vision was considered as awareness of diabetic eye disease.

RESULTS

A total of 3273 participants were interviewed. Among them, 56.2% (n = 1840) were women, 60.6% (n = 1985) had no formal education, and 50.2% (n = 1645) were from the Khammam district. The mean age of the participants was 55.3 years (standard deviation: 11.7 years). Awareness of diabetes was 52.5% (n = 1719). Among them, 1056 participants (61.4%) were aware that diabetes could affect vision.

CONCLUSION

Only half of the participants were aware of diabetes and of this substantial proportion of individuals was unaware of potential vision loss due to diabetes. Improving awareness about diabetes and its impact on vision is recommended to prevent potential vision loss in this population.

Updates on medical and surgical managements of diabetic retinopathy and maculopathy

Diabetic retinopathy (DR) and diabetic macular edema (DME) are leading causes of vision loss globally. This is a comprehensive review focused on both medical and surgical management strategies for DR and DME. This review highlights the epidemiology of DR and DME, with a particular emphasis on the Asia-Pacific region, urban-rural disparities, ethnic variations, and grading methodologies. We examine various risk factors for DR, including glycemic control, hypertension, hyperlipidemia, obesity, chronic kidney disease, sex, myopia, pregnancy, and cataract surgery. Furthermore, we explore potential biomarkers in serum, proteomics, metabolomics, vitreous, microRNA, and genetics that may aid in the detection and management of DR. In addition to medical management, we review the evidence supporting systemic and ocular treatments for DR/DME, including anti-vascular endothelial growth factor (anti-VEGF) agents, anti-inflammatory agents, biosimilars, and integrin inhibitors. Despite advancements in treatment options such as pan-retinal photocoagulation and anti-VEGF agents, a subset of cases still progresses, necessitating vitrectomy. Challenging diabetic vitrectomies pose difficulties due to complex fibrovascular proliferations, incomplete posterior vitreous detachment, and fragile, ischemic retinas, making membrane dissection risky and potentially damaging to the retina. In this review, we address the question of challenging diabetic vitrectomies, providing insights and strategies to minimize complications. Additionally, we briefly explore newer modalities such as 3-dimensional vitrectomy and intra-operative optical coherence tomography as potential tools in diabetic vitrectomy. In conclusion, this review provides a comprehensive overview of both medical and surgical management options for DR and DME. It underscores the importance of a multidisciplinary approach, tailored to the needs of each patient, to optimize visual outcomes and improve the quality of life for those affected by these sight-threatening conditions.

Functional diabetic retinopathy: A new concept to improve management of diabetic retinal diseases

Multifocal functional tests are not routinely performed in diabetic retinopathy (DR) and diabetic macular edema (DME) management. We emphasise their importance and coin the term functional diabetic retinopathy (FDR). We reviewed current guidelines on management of DR/DME, and literature on diabetic retinal neurodegeneration (DRN) and functional deficits in DR/DME. Functional visual loss due to DRN precedes vasculopathy and clinical DR; however, currently the diagnosis and management of DR/DME are based on classical signs of retinal vasculopathy and structural changes shown by funduscopy, fundus photographs, and optical coherence tomography (OCT). Furthermore, DME can mask DRN-based retinal layer thinning by OCT and is focussed on the macular region. The only functional test recommended in national and international guidelines on DR/DME is best-corrected visual acuity, a test of foveal function (<1 % of retina). Multifocal functional tests can objectively characterize both foveal and extrafoveal, localized and global, function. Current recommendations for DR/DME screening are inadequate to detect FDR affecting the greater retina. Early detection of FDR using multifocal functional tests could bring DR/DME management strategies forward enabling prevention of the later stage vision-threatening complications. After all, the end point of patient care is functional outcomes.

Prevalence of microvascular complications and associated factors among diabetes mellitus patients in Ethiopia: Systematic review and meta-analysis

BACKGROUND

Diabetes mellitus (DM) is a metabolic abnormality affecting 537 million people worldwide. Poor glycemic control, longer duration, and poor medication adherence increased the risk of DM complications. Comprehensive evidence on the pooled prevalence of microvascular complications in DM patients in Ethiopia is not available. Furthermore, individual study findings for the prevalence of microvascular complications in DM patients, and associated factors were not consistent.

OBJECTIVE

This systemic review and meta-analysis aimed to assess the pooled prevalence of microvascular complications in DM patients, and its associated risk factors in Ethiopia.

METHODS

Systematic search on Scopus, PubMed, Science Direct electronic database, Google Scholar search engine, and library registration was used to identify relevant studies following reviews and meta-analysis guidelines. Microsoft Excel spreadsheets were used to extract data, and Extracted data was analyzed using STATA software version 17.0. A Sensitivity analysis was conducted to assess the role of each study in the final result and the presence of publication bias was assessed by Egger's test. Heterogeneity across studies was checked by Cochran's Q statistic and I2 statistics and significant heterogeneity was assessed using subgroup analysis.

RESULTS

The pooled prevalence of microvascular complications in DM patients was 32.89 % (95 % CI: 28.17-37.60). In addition, the pooled prevalence of retinopathy, neuropathy, and nephropathy in DM patients was 17.16 % (95 % CI: 12-22 %), 10.49 % (95 % CI: 8-13 %) and 11.52 % (95 % CI: 9-15 %) respectively. Age >60 years old (AOR = 1.08 (95%CI = 1.02-1.15), longer duration of DM (AOR = 1.57 (95 % CI = 1.31-1.84), poor glycemic control (AOR = 2.21 (95 % CI = 1.52-2.91), poor adherence to diabetic medications (AOR = 3.61 (95 % CI = 1.83-5.38) and presence of hypertension (AOR = 2.26 (95 % CI = 1.73-2.80) ware associated risk factors for microvascular complications in DM patients.

CONCUSSION

Around one-third of DM patients had one or more microvascular complications. Patients with advanced age, longer duration of DM, poor glycemic control, poor medication adherence, and comorbidity like hypertension should be targeted to tackle the occurrence and severity of microvascular complications in DM patients.

PROTOCOL REGISTRATION

The review protocol was developed and was registered with PROSPERO registration number (CRD42023486459).

Inhibition of Cullin3 Neddylation Alleviates Diabetic Retinopathy by Activating Nrf2 Signaling to Combat ROS-Induced Oxidative Stress and Inflammation

Oxidative stress and inflammation induced by reactive oxygen species (ROS) play important roles in the development of diabetic retinopathy (DR). Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, which is negatively controlled by Cullin3-RING E3 ligase (CRL3) and controls ROS levels, is compromised in DR. CRL3 activity is regulated by Cullin3 neddylation. Nonetheless, the relationship between Cullin3 neddylation and DR remains uncertain. The goal of this study was to evaluate the effect of Cullin3 neddylation on DR and its underlying mechanisms by utilizing MLN4924, a neddylation inhibitor. Cullin3 neddylation was elevated in diabetic rats' retinas as well as in advanced glycation end products (AGEs)-induced endothelial cells. Inhibiting neddylation of Cullin3 with MLN4924 downregulated Nrf2 ubiquitination, promoted Nrf2 accumulation, suppressed ROS-induced oxidative stress and inflammation, and attenuated blood-retinal barrier (BRB) breakdown in both diabetic vivo and vitro models. However, the beneficial impact of MLN4924 was compromised when Nrf2 was suppressed with siRNA in vitro. This study showed that inhibition of Cullin3 neddylation with MLN4924 exerted protective effect on DR by activating Nrf2 signaling to inhibit ROS-induced retinal injury, which indicated that targeting Cullin3 neddylation could be a promising treatment option for DR.

The adaptive immune system in the retina of diabetics

As the prevalence of diabetes mellitus increases each year, its most common microvascular complication, diabetic retinopathy (DR), is also on the rise. DR is now regarded as an inflammatory disease in which innate immunity plays a crucial role, and a large number of innate immune cells with associated cytokines are involved in the pathologic process of DR. The role of adaptive immunity in DR is seldom mentioned, probably due to the general perception of the immune privileged environment of the retina; however, in recent years there has been a gradual increase in research on the role of adaptive immunity in DR, and with the discovery of the retinal lymphatic system, it seems that the role of adaptive immunity can no longer be ignored. Here, we discuss the immunosuppressive environment of the retina, the phenomenon and potential mechanisms of lymphocyte infiltration in DR, and the role of the adaptive immune system in the diabetic retina, which may point the way for future research.

Cost-effectiveness of AI-based diabetic retinopathy screening in nationwide health checkups and diabetes management in Japan: A modeling study

AIMS

We evaluated the cost-effectiveness of artificial intelligence (AI)-based diabetic retinopathy (DR) screening in Japan. This evaluation compared the simultaneous introduction of AI in nationwide health checkups, namely "specific health check-ups in Japan" (SHC), and diabetes complication management (AI-case) with the current situation where AI is not being introduced (conventional-case) from the healthcare payer's perspective.

METHODS

A cost-effectiveness analysis was conducted using a new individual-based state transition model. Model parameters, including the incidence and progression of DR, health utility values, and costs of screening and treatment, were based on literature data and expert opinion. The analysis estimated quality-adjusted life years (QALYs), cumulative costs, and incremental cost-effectiveness ratios (ICER).

RESULTS

The ICER comparing the AI-case with conventional-case was estimated to be JPY 1,598,244/QALY (USD 11,375/QALY), which is below the willingness-to-pay threshold of JPY 5 million/QALY (USD 35,584/QALY). Scenario analyses revealed that ICERs for the AI-based DR screening in SHC-only condition was JPY 1,895,226/QALY (USD 13,488/QALY) and JPY 3,960,839/QALY (USD 28,189/QALY) in diabetes management-only condition.

CONCLUSIONS

The introduction of AI-based DR screening for SHC and diabetes management was cost-effective compared to the current situation in Japan.

Enhancing Ophthalmic Diagnosis and Treatment with Artificial Intelligence

The integration of artificial intelligence (AI) in ophthalmology is transforming the field, offering new opportunities to enhance diagnostic accuracy, personalize treatment plans, and improve service delivery. This review provides a comprehensive overview of the current applications and future potential of AI in ophthalmology. AI algorithms, particularly those utilizing machine learning (ML) and deep learning (DL), have demonstrated remarkable success in diagnosing conditions such as diabetic retinopathy (DR), age-related macular degeneration, and glaucoma with precision comparable to, or exceeding, human experts. Furthermore, AI is being utilized to develop personalized treatment plans by analyzing large datasets to predict individual responses to therapies, thus optimizing patient outcomes and reducing healthcare costs. In surgical applications, AI-driven tools are enhancing the precision of procedures like cataract surgery, contributing to better recovery times and reduced complications. Additionally, AI-powered teleophthalmology services are expanding access to eye care in underserved and remote areas, addressing global disparities in healthcare availability. Despite these advancements, challenges remain, particularly concerning data privacy, security, and algorithmic bias. Ensuring robust data governance and ethical practices is crucial for the continued success of AI integration in ophthalmology. In conclusion, future research should focus on developing sophisticated AI models capable of handling multimodal data, including genetic information and patient histories, to provide deeper insights into disease mechanisms and treatment responses. Also, collaborative efforts among governments, non-governmental organizations (NGOs), and technology companies are essential to deploy AI solutions effectively, especially in low-resource settings.

Prevalence of Retinal Vascular Diseases in a Tertiary Care Hospital in Türkiye: A Hospital-Based Epidemiologic Study

Objectives

To determine the prevalence of diabetic retinopathy (DR), retinal vein occlusion (RVO), and retinal artery occlusion (RAO) in a tertiary care hospital in Türkiye.

Materials and Methods

The electronic records of all patients over the age of 18 years admitted to a tertiary care general hospital between January 2022 and January 2024 were retrospectively analyzed. For each of the three diseases, demographic data such as age, sex, and common complications were evaluated.

Results

A total of 140,344 patients were retrospectively analyzed. Of these patients, 44.6% (n=62,575) were male and 55.4% (n=77,769) were female. The number of patients diagnosed with retinal vascular disease was 1,963 and 52.3% (n=1,028) of these patients were female. The prevalence of retinal vascular diseases in the general population was 1.4% (95% confidence interval [CI]: 1.34% to 1.46%). The prevalence of DR, RVO, and RAO was 1.12% (95% CI: 1.07% to 1.18%), 0.27% (95% CI: 0.24% to 0.3%), and 0.01% (95% CI: 0% to 0.01%), respectively. Among these three diseases, DR was statistically more common in women (p=0.048) and RAO in men (p=0.015), while RVO (p=0.079) was not associated with sex. In patients with DR, macular edema was more common in patients older than 50 years, while neovascularization was more common in patients younger than 50 years. The development of macular edema and neovascularization was not associated with sex in patients with these three diseases.

Conclusion

This is the first study to report the demographic data of patients diagnosed with retinal vascular diseases in Türkiye. However, there is a need for nationwide, multicenter, hospital and community-based studies including different geographical regions of Türkiye that examine the data of patients in detail.

Role of Diabetes Self-management Education for Our Health Systems and Economy

CONTEXT

Diabetes mellitus is a global health burden, with factors contributing to its prevalence and costs. Educating people with diabetes improves outcomes and affects the economic burden on the individual and health systems.

EVIDENCE ACQUISITION

We included recent diabetes data from the Centers for Disease Control and Prevention and articles from PubMed and Ovid MEDLINE.

EVIDENCE SYNTHESIS

Diabetes prevalence in the United States increased from 10.3% in 2001 to 14.7% in 2021. Factors contributing are an aging population, increased obesity, and social determinants of health. Total costs for diabetes in 2022 reached $412.9 billion, consisting of 74% direct medical and around 26% indirect costs. The highest medical expenses were hospital inpatient services ($96.2 billion), and indirect costs were decreased productivity while at work ($35.8 billion). The effect on the health economy in the United States and globally is only increasing. Interventions to improve disease outcomes such as diabetes education programs that teach self-management skills, healthy lifestyle behaviors, and coping strategies have improved glycated hemoglobin A1c and other outcomes. The economic effect of education is not well studied. However, the Diabetes Prevention Program demonstrated the benefits of lifestyle-based education in preventing or delaying the development of type 2 diabetes in high-risk people and in being cost-effective long term.

CONCLUSION

High direct and indirect costs and the prevalence of diabetes require urgent global awareness and interventions from many angles. We encourage clinicians and agencies to prioritize the education of people living with diabetes to prevent and treat diabetes and its complications.

Development and validation of predictive models for diabetic retinopathy using machine learning

OBJECTIVE

This study aimed to develop and compare machine learning models for predicting diabetic retinopathy (DR) using clinical and biochemical data, specifically logistic regression, random forest, XGBoost, and neural networks.

METHODS

A dataset of 3,000 diabetic patients, including 1,500 with DR, was obtained from the National Population Health Science Data Center. Significant predictors were identified, and four predictive models were developed. Model performance was assessed using accuracy, precision, recall, F1-score, and area under the curve (AUC).

RESULTS

Random forest and XGBoost demonstrated superior performance, achieving accuracies of 95.67% and 94.67%, respectively, with AUC values of 0.991 and 0.989. Logistic regression yielded an accuracy of 76.50% (AUC: 0.828), while neural networks achieved 82.67% accuracy (AUC: 0.927). Key predictors included 24-hour urinary microalbumin, HbA1c, and serum creatinine.

CONCLUSION

The study highlights random forest and XGBoost as effective tools for early DR detection, emphasizing the importance of renal and glycemic markers in risk assessment. These findings support the integration of machine learning models into clinical decision-making for improved patient outcomes in diabetes management.

The Role of Diet and Oral Supplementation for the Management of Diabetic Retinopathy and Diabetic Macular Edema: A Narrative Review

Globally, diabetic retinopathy (DR) and diabetic macular edema (DME) are the leading causes of visual loss in working people. Current treatment approaches mostly target proliferative DR and DME, such as intravitreal injections of antivascular endothelial growth factor agents and laser photocoagulation. Before DR progresses into the more severe, sight-threatening proliferative stage, patients with early stages of the disease must get early and appropriate care. It has been suggested that nutraceuticals, which are natural functional foods with minimal adverse effects, may help diabetic patients with DR and DME. Several in vitro and in vivo studies were carried out over the last years, showing the potential benefits of several nutraceuticals in DR due to their neuroprotective, vasoprotective, anti-inflammatory, and antioxidant properties. Although most of the research is restricted to animal models and many nutraceuticals have low bioavailability, these compounds may adjuvate and implement conventional DR therapies. The purpose of this review is (i) to summarize the complex pathophysiology underlying DR and DME and (ii) to examine the main natural-derived molecules and dietary habits that can assist conventional therapies for the clinical management of DR and DME.

Construction of a nomogram for predicting the risk of all-cause mortality in patients with diabetic retinopathy

Background

Diabetic retinopathy (DR) not only leads to visual impairment but also increases the risk of death in type 2 diabetes patients. This study aimed to construct a nomogram to assess the risk of all-cause mortality in patients with DR.

Methods

This cross-sectional study included 1004 patients from the National Health and Nutrition Examination Survey database (NHANES) between 1999-2018. Participants were randomized in a 7:3 ratio into a training set and a test set. We selected predictors by LASSO regression and multifactorial Cox proportional risk regression analysis and constructed nomograms, guided by established clinical guidelines and expert consensus as the gold standard. We used the concordance index (C-index), receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) to evaluate the nomogram's discriminative power, calibration quality, and clinical use.

Results

The training and test sets consisted of 703 and 301 participants with a median age of 64 and 63 years, respectively. The study identified seven predictors, including age, marital status, congestive heart failure (CHF), coronary heart disease (CHD), stroke, creatinine level, and taking insulin. The C-index of the nomogram model constructed from the training set was 0.738 (95% CI: 0.704-0.771), while the C-index of the test set was 0.716 (95% CI: 0.663-0.768). In the training set, the model's AUC values for predicting all-cause mortality risk at 3 years, 5 years, and 10 years were 0.739, 0.765, and 0.808, respectively. In the test set, these AUC values were 0.737, 0.717, and 0.732, respectively. The ROC curve, calibration curve, and DCA curve all demonstrated excellent predictive performance, confirming the model's effectiveness and reliability in clinical applications.

Conclusions

Our nomogram demonstrates high clinical predictive accuracy, enabling clinicians to effectively predict the overall mortality risk in patients with DR, thereby significantly improving their prognosis.

An evidence mapping study based on systematic reviews of traditional Chinese medicine (TCM) for diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of vision impairment and blindness among individuals with diabetes. Traditional Chinese medicine (TCM) has been explored as an alternative treatment for DR, but the quality of evidence remains uncertain. A comprehensive evidence mapping study is necessary to synthesize existing SRs, identify gaps in the literature, and highlight areas requiring further research.

OBJECTIVE

This study aims to evaluate the reporting and methodological quality of SRs on TCM for DR and to assess the effectiveness of TCM interventions using an evidence-mapping approach.

METHODS

A comprehensive search of major biomedical databases to identify relevant SRs published up to November 2023. The reporting quality of the included SRs was assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, while the methodological quality was evaluated using the Assessment of Multiple Systematic Reviews 2 (AMSTAR 2) tool.

RESULTS

A total of 51 SRs involving 131,084 participants were included in the analysis. Evidence mapping indicated that TCM is relatively effective in treating DR. However, the methodological quality and reporting standards of these SRs were generally suboptimal. According to the AMSTAR 2 assessment, only one SR (2%) was rated as high quality, 29 SRs (56.9%) were of moderate quality, 20 SRs (39.2%) were of low quality, and one SR (2%) was of critically low quality. While all studies adequately reported the PICO components, risk of bias assessment, and statistical methods, none provided information on funding sources. Furthermore, only one study (2%) included a list of excluded studies with reasons, and eight SRs (15.7%) documented pre-specified protocols. Common reporting deficiencies included incomplete protocol and registration details, unclear review rationales, and insufficient presentation of relevant outcome data.

CONCLUSION

This evidence mapping study highlights the potential benefits of TCM for treating DR while identifying significant gaps in the existing literature. Although TCM interventions show potential benefits for treating DR, the overall quality of SRs is suboptimal. Future research should focus on addressing these gaps, particularly in areas such as funding disclosure and methodological rigor, to enhance the reliability of evidence on TCM interventions for DR.