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

Targeting Phospholipase D Pharmacologically Prevents Phagocytic Function Loss of Retinal Pigment Epithelium Cells Exposed to High Glucose Levels

We previously described the participation of canonical phospholipase D isoforms (PLD1 and PLD2) in the inflammatory response of retinal pigment epithelium (RPE) cells exposed to high glucose concentrations (HG). Here, we studied the role of the PLD pathway in RPE phagocytic function. For this purpose, ARPE-19 cells were exposed to HG (33 mM) or to normal glucose concentration (NG, 5.5 mM) and phagocytosis was measured using pHrodo™ green bioparticles^® or photoreceptor outer segments (POS). HG exposure for 48 and 72 h reduced phagocytic function of ARPE-19 cells, and this loss of function was prevented when cells were treated with 5 μM of PLD1 (VU0359595 or PLD1i) or PLD2 (VU0285655-1 or PLD2i) selective inhibitors. Furthermore, PLD1i and PLD2i did not affect RPE phagocytosis under physiological conditions and prevented oxidative stress induced by HG. In addition, we demonstrated PLD1 and PLD2 expression in ABC cells, a novel human RPE cell line. Under physiological conditions, PLD1i and PLD2i did not affect ABC cell viability, and partial silencing of both PLDs did not affect ABC cell POS phagocytosis. In conclusion, PLD1i and PLD2i prevent the loss of phagocytic function of RPE cells exposed to HG without affecting RPE function or viability under non-inflammatory conditions.

Two Singapore public healthcare AI applications for national screening programs and other examples

This article explains how two AI systems have been incorporated into the everyday operations of two Singapore public healthcare nation-wide screening programs. The first example is embedded within the setting of a national level population health screening program for diabetes related eye diseases, targeting the rapidly increasing number of adults in the country with diabetes. In the second example, the AI assisted screening is done shortly after a person is admitted to one of the public hospitals to identify which inpatients-especially which elderly patients with complex conditions-have a high risk of being readmitted as an inpatient multiple times in the months following discharge. Ways in which healthcare needs and the clinical operations context influenced the approach to designing or deploying the AI systems are highlighted, illustrating the multiplicity of factors that shape the requirements for successful large-scale deployments of AI systems that are deeply embedded within clinical workflows. In the first example, the choice was made to use the system in a semi-automated (vs. fully automated) mode as this was assessed to be more cost-effective, though still offering substantial productivity improvement. In the second example, machine learning algorithm design and model execution trade-offs were made that prioritized key aspects of patient engagement and inclusion over higher levels of predictive accuracy. The article concludes with several lessons learned related to deploying AI systems within healthcare settings, and also lists several other AI efforts already in deployment and in the pipeline for Singapore's public healthcare system.

American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update

OBJECTIVE

The objective of this clinical practice guideline is to provide updated and new evidence-based recommendations for the comprehensive care of persons with diabetes mellitus to clinicians, diabetes-care teams, other health care professionals and stakeholders, and individuals with diabetes and their caregivers.

METHODS

The American Association of Clinical Endocrinology selected a task force of medical experts and staff who updated and assessed clinical questions and recommendations from the prior 2015 version of this guideline and conducted literature searches for relevant scientific papers published from January 1, 2015, through May 15, 2022. Selected studies from results of literature searches composed the evidence base to update 2015 recommendations as well as to develop new recommendations based on review of clinical evidence, current practice, expertise, and consensus, according to established American Association of Clinical Endocrinology protocol for guideline development.

RESULTS

This guideline includes 170 updated and new evidence-based clinical practice recommendations for the comprehensive care of persons with diabetes. Recommendations are divided into four sections: (1) screening, diagnosis, glycemic targets, and glycemic monitoring; (2) comorbidities and complications, including obesity and management with lifestyle, nutrition, and bariatric surgery, hypertension, dyslipidemia, retinopathy, neuropathy, diabetic kidney disease, and cardiovascular disease; (3) management of prediabetes, type 2 diabetes with antihyperglycemic pharmacotherapy and glycemic targets, type 1 diabetes with insulin therapy, hypoglycemia, hospitalized persons, and women with diabetes in pregnancy; (4) education and new topics regarding diabetes and infertility, nutritional supplements, secondary diabetes, social determinants of health, and virtual care, as well as updated recommendations on cancer risk, nonpharmacologic components of pediatric care plans, depression, education and team approach, occupational risk, role of sleep medicine, and vaccinations in persons with diabetes.

CONCLUSIONS

This updated clinical practice guideline provides evidence-based recommendations to assist with person-centered, team-based clinical decision-making to improve the care of persons with diabetes mellitus.

Potential impact of fluorescein angiography as a primary imaging modality in the management of diabetic retinopathy

Purpose

To evaluate current practice patterns for Egyptian ophthalmologists in the diagnosis of diabetic retinopathy (DR) and explore potential implications of these approaches on management.

Methods

Cross-sectional survey conducted in Egypt amongst practicing ophthalmologists.

Results

The study had 203 responses (~6% of all Egyptian ophthalmologists). A majority of respondents were general ophthalmologists (78.2%), practicing for five to ten years (41.9%). In patients with DR and no diabetic macular edema (DME), 33.0% of respondents would use FA in patients with mild DR, 44.3% in patients with moderate DR and 51.2% in patients with severe non-proliferative diabetic retinopathy (NPDR). Color imaging (CI) was used by less than 1% as the sole imaging modality for any level of DR. Approximately 70% of respondents used fluorescein angiography (FA) to grade and base treatment decisions for DR, either alone or in conjunction with dilated eye exams and/or CI. Given the known more severe appearance of DR on FA than on standard color imaging upon which treatment guidelines are based, use of FA as the primary modality over a one-year period could result in PRP that would otherwise not be suggested in approximately 78,820 eyes at an additional cost of $10.1 million US dollars. These numbers are projected to double by 2045.

Conclusion

Given that FA detects significantly greater pathology than CI, and that treatment and follow-up recommendations are based on CI, its use as the primary imaging modality in DR grading may result in apparently significantly higher DR severity, with subsequently increased procedures and associated costs.

Effect of urinary albumin creatinine ratio on type 2 diabetic retinopathy and is cut-off value for early diabetic retinopathy diagnosis

OBJECTIVE

To evaluate the effect of Urinary albumin creatinine ratio (UACR) on diabetic retinopathy (DR) in People with Type 2 diabetes (T2D) and the cut-off value of UACR for predicting DR using receiver operating characteristic curve (ROC).

METHODS

A prospective cohort study of 2490 people with T2D was conducted with follow-up ranging from 3 to 10 years, with a mean follow-up of 7 years. Dilated fundus examination and urine examination were performed annually. Medical history and clinical data were collected and analyzed. Linear mixed effect models with unstructured variance-covariance were carried out to longitudinally assess the influence of UACR and other factors on DR, and ROC curve was drawn to evaluate the value of UACR in early diagnosis of DR.

RESULTS

Linear Mixed-effect models revealed that UACR was positively correlated with the development of DR (β = 0.001, 95 %CI: 1.023-1.241, P < 0.001). The area under the ROC curve for UACR was 0.634 (95 %CI: 0.605-0.664, P < 0.001), cut-off value for early diagnosis of DR was 27.81 mg/g, the sensitivity was 0.586, and the specificity was 0.632.

CONCLUSION

UACR can predict the occurrence of DR in people with T2D, so it can be considered as a preliminary indicator of DR.

Study on the Development of a Conceptual Framework to Identify the Risk Factors of Diabetic Retinopathy among Diabetic Patients: A Concept Paper

The most common complication of diabetes mellitus (DM) is diabetic retinopathy (DR). The control of DR risk factors is essential for the effective prevention of DR. There is currently a lack of research to guide DR-related research in Malaysia. This concept paper aimed to review published studies and propose a conceptual framework (CF) as a guide for future research to determine the prevalence of DR and its risk factors across DM patients. After a review of prior research, this study has presented a CF that takes into account these four key elements: the patient's sociodemographic characteristics, comorbidities, complications, and diabetes conditions, namely, the length of the disease and glycaemic control. In the suggested CF, ethnicity was highlighted as a crucial risk factor for DR across lower- to middle-income countries (LMIC) and multiracial countries. In order to guide future studies, scientific guidance is essential. The proposed CF would help future research to conduct scientific research related to DR. Also, the proposed CF was tailored to suit research across LMIC and multiracial countries.

Metabolomics in Diabetic Retinopathy: From Potential Biomarkers to Molecular Basis of Oxidative Stress

Diabetic retinopathy (DR), the leading cause of blindness in working-age adults, is one of the most common complications of diabetes mellitus (DM) featured by metabolic disorders. With the global prevalence of diabetes, the incidence of DR is expected to increase. Prompt detection and the targeting of anti-oxidative stress intervention could effectively reduce visual impairment caused by DR. However, the diagnosis and treatment of DR is often delayed due to the absence of obvious signs of retina imaging. Research progress supports that metabolomics is a powerful tool to discover potential diagnostic biomarkers and therapeutic targets for the causes of oxidative stress through profiling metabolites in diseases, which provides great opportunities for DR with metabolic heterogeneity. Thus, this review summarizes the latest advances in metabolomics in DR, as well as potential diagnostic biomarkers, and predicts molecular targets through the integration of genome-wide association studies (GWAS) with metabolomics. Metabolomics provides potential biomarkers, molecular targets and therapeutic strategies for controlling the progress of DR, especially the interventions at early stages and precise treatments based on individual patient variations.

Risk factors for the development or progression of diabetic retinopathy in pregnancy: Meta‐analysis and systematic review

BACKGROUND

Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population, and it increases in severity during pregnancy.

METHODS

Systematic review of literature from PubMed, Cochrane Library and Web of Science using keywords 'diabetic retinopathy' and 'pregnancy' and 'progression' from inception to 2021 was completed. Included studies were (1) peer-reviewed observational studies addressing progression/development of DR in pregnancy, (2) provided the number of diabetic patients that developed/progressed in DR during pregnancy, and (3) included differential data on variables between progression and non-progression groups. This was applied by two independent researchers and referred to a third researcher as necessary. Twenty-seven of the original 138 studies met this criterion. Data were pooled and analysed using fixed-effects in meta-analysis.

RESULTS

From 27 studies, 2537 patients were included. Pre-eclampsia [Risk Ratio (RR) 2.62 (95% CI = 1.72, 4.00)] and hypertension treatment during pregnancy [RR 2.74 (95% CI = 1.72, 4.00)] were significantly associated with the development/progression of DR. HbA1c at baseline [MD 0.82 (95% CI = 0.59, 1.06)], duration of diabetes [mean difference (MD) 5.97 (95% CI = 5.38, 6.57)], and diastolic blood pressure at baseline [MD 3.29 (95% CI = 0.46, 6.12)] were all significantly higher in the progression group while only mean birth weight [MD -0.17 (95% CI = -0.31, -0.03)] was significantly higher in the non-progression group.

CONCLUSIONS

This study fills a gap in the literature and provide physicians with more information on the risk factors associated with the progression of DR in pregnancy and how to counsel this vulnerable patient population appropriately.

SARS-CoV-2 infection and diabetes: Pathophysiological mechanism of multi-system organ failure

Since the discovery of the coronavirus disease 2019 outbreak, a vast majority of studies have been carried out that confirmed the worst outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in people with preexisting health conditions, including diabetes, obesity, hypertension, cancer, and cardiovascular diseases. Likewise, diabetes itself is one of the leading causes of global public health concerns that impose a heavy global burden on public health as well as socio-economic development. Both diabetes and SARS-CoV-2 infection have their independent ability to induce the pathogenesis and severity of multi-system organ failure, while the co-existence of these two culprits can accelerate the rate of disease progression and magnify the severity of the disease. However, the exact pathophysiology of multi-system organ failure in diabetic patients after SARS-CoV-2 infection is still obscure. This review summarized the organ-specific possible molecular mechanisms of SARS-CoV-2 and diabetes-induced pathophysiology of several diseases of multiple organs, including the lungs, heart, kidneys, brain, eyes, gastrointestinal system, and bones, and sub-sequent manifestation of multi-system organ failure.

Expert Panel Consensus for Addressing Anti-VEGF Treatment Challenges of Diabetic Macular Edema in Spain

Purpose

The treatment of diabetic macular edema (DME) has evolved rapidly in the past decade, highlighting the need to address the challenges of routine clinical practice decision-making through expert consensus agreements.

Methods

After a literature review and discussion of real-world experience on DME management, a group of ten retina specialists agreed on a consensus of recommendations for the most appropriate management of DME patients using vascular endothelial growth factor inhibitors (anti-VEGF) in Spain.

Results

The panel recommended early treatment initiation in DME patients with worse baseline visual acuity (VA) to maintain or improve outcome. For patients with good VA, an observation strategy was recommended, considering the presence of diabetic retinopathy, optical coherence tomography biomarkers, and impact on patient's quality of life. Based on the available evidence and clinical experience, the panel recommended the use of anti-VEGF intensive loading doses with the objective of achieving anatomic and visual responses as soon as possible, followed by a Treat & Extend (T&E) strategy to maintain VA improvement. Aflibercept was recommended for patients with a baseline decimal VA <0.5, followed by a T&E strategy, including the possibility to extend frequency of injections up to 16 weeks.

Conclusion

An expert panel proposes a consensus for the management of DME in Spain. Early treatment initiation with anti-VEGF in DME patients is recommended to maintain or improve VA; aflibercept is recommended for patients with a poor baseline VA.

Associations between psycho-behavioral risk factors and diabetic retinopathy: NHANES (2005-2018)

Introduction

Diabetes mellitus (DM) and diabetic retinopathy (DR) increase the global burden. Since their pathogenesis is complex, it is necessary to use the biopsychosocial model to discover the most effective strategies. The study is aimed to investigate the psycho-behavioral factors of DR and confirm the discrepancies from previous studies.

Research design and methods

The study comprised seven cycles of cross-sectional data of the National Health and Nutrition Examination Survey (NHANES) from 2005-2006 to 2017-2018. Samples of DM were selected from this complex multi-stage probability sample and divided into the non-DR and DR groups, where 4,426 samples represented 18,990,825 individuals after weighting. This study comprehensively explored the biological, social, and psychological risk factors of DR, among which the biological factors included blood pressure, blood routine, HbA1c%, blood glucose, the duration of DM, family history, comorbidities, and treatment methods. Social aspects include gender, education, income, insurance, smoking, drinking, sleep habits, and recreational activities. The Patient Health Questionnaire-9 (PHQ-9) was used to assess the psychological state. Taylor series regression was used to examine the connection between factors and DR.

Results

Men accounted for 55.5% of the DR group (P = 0.0174). Lymphocyte count, insulin treatment, heart failure, stroke, liver condition, and renal failure showed significant differences in DR (P < 0.05). The incidence of depression in DR was 40.5%. Mild to moderate depression [odds ratio was associated with DR [(OR) = 1.37, 95% confidence interval (CI): 1.06-1.79], but there was no statistical difference in severe depression (OR = 1.34, 95% CI: 0.83-2.17). Although ≤ 6 h of sleep was associated with DR (OR = 1.38, 95% CI: 1.01-1.88), we found no statistical differences in alcohol consumption, recreational activities, or sedentary time between the two groups in our current study (P > 0.05).

Conclusions

The biological risk factors of DR are significant. It showed that stroke is associated with DR, and retinal exams have the potential value as a screening tool for the brain. Besides, psycho-behavioral risk factors of DR should also be paid attention. Our study highlights that mild and moderate depression and ≤6 h of sleep are distinguishably associated with DM complicated with DR. It indicates that psycho-behavioral risk factors confer a vital influence on diabetic health care and DR.

Focused Attention in Transformers for interpretable classification of retinal images

Vision Transformers have recently emerged as a competitive architecture in image classification. The tremendous popularity of this model and its variants comes from its high performance and its ability to produce interpretable predictions. However, both of these characteristics remain to be assessed in depth on retinal images. This study proposes a thorough performance evaluation of several Transformers compared to traditional Convolutional Neural Network (CNN) models for retinal disease classification. Special attention is given to multi-modality imaging (fundus and OCT) and generalization to external data. In addition, we propose a novel mechanism to generate interpretable predictions via attribution maps. Existing attribution methods from Transformer models have the disadvantage of producing low-resolution heatmaps. Our contribution, called Focused Attention, uses iterative conditional patch resampling to tackle this issue. By means of a survey involving four retinal specialists, we validated both the superior interpretability of Vision Transformers compared to the attribution maps produced from CNNs and the relevance of Focused Attention as a lesion detector.

A Paradigm Shift in the Management Approaches of Proliferative Diabetic Retinopathy: Role of Anti-VEGF Therapy

Diabetic retinopathy (DR) is considered one of the leading causes of vision loss globally. It principally causes upregulation of pro-angiogenic, proinflammatory, and vascular permeability factors such as vascular endothelial growth factor (VEGF), leading to neovascularisation. The advanced stage of DR or proliferative diabetic retinopathy (PDR) is of more concern, as it leads to vitreous haemorrhage and traction retinal detachment. Various risk factors associated with PDR include hyperglycemia, hypertension, neuropathy, dyslipidemia, anaemia, nephropathy, and retinal complications of drugs used for diabetes. Current management approaches for PDR have been stratified and involve pan-retinal photocoagulation, vitrectomy, and anti-VEGF agents. Given the emerging role of anti-VEGF agents as a favourable adjunct or alternative therapy, they have a critical role in the management of PDR. The review emphasises current management approaches for PDR focusing on anti-VEGF therapy. The review also highlights the risk/benefit evaluation of the various approaches employed for PDR management in various clinical scenarios.

Diabetic retinopathy screening in the emerging era of artificial intelligence

Diabetic retinopathy is a frequent complication in diabetes and a leading cause of visual impairment. Regular eye screening is imperative to detect sight-threatening stages of diabetic retinopathy such as proliferative diabetic retinopathy and diabetic macular oedema in order to treat these before irreversible visual loss occurs. Screening is cost-effective and has been implemented in various countries in Europe and elsewhere. Along with optimised diabetes care, this has substantially reduced the risk of visual loss. Nevertheless, the growing number of patients with diabetes poses an increasing burden on healthcare systems and automated solutions are needed to alleviate the task of screening and improve diagnostic accuracy. Deep learning by convolutional neural networks is an optimised branch of artificial intelligence that is particularly well suited to automated image analysis. Pivotal studies have demonstrated high sensitivity and specificity for classifying advanced stages of diabetic retinopathy and identifying diabetic macular oedema in optical coherence tomography scans. Based on this, different algorithms have obtained regulatory approval for clinical use and have recently been implemented to some extent in a few countries. Handheld mobile devices are another promising option for self-monitoring, but so far they have not demonstrated comparable image quality to that of fundus photography using non-portable retinal cameras, which is the gold standard for diabetic retinopathy screening. Such technology has the potential to be integrated in telemedicine-based screening programmes, enabling self-captured retinal images to be transferred virtually to reading centres for analysis and planning of further steps. While emerging technologies have shown a lot of promise, clinical implementation has been sparse. Legal obstacles and difficulties in software integration may partly explain this, but it may also indicate that existing algorithms may not necessarily integrate well with national screening initiatives, which often differ substantially between countries.

The pathophysiological mechanisms underlying diabetic retinopathy

Diabetic retinopathy (DR) is the most common complication of diabetes mellitus (DM), which can lead to visual impairment and even blindness in severe cases. DR is generally considered to be a microvascular disease but its pathogenesis is still unclear. A large body of evidence shows that the development of DR is not determined by a single factor but rather by multiple related mechanisms that lead to different degrees of retinal damage in DR patients. Therefore, this article briefly reviews the pathophysiological changes in DR, and discusses the occurrence and development of DR resulting from different factors such as oxidative stress, inflammation, neovascularization, neurodegeneration, the neurovascular unit, and gut microbiota, to provide a theoretical reference for the development of new DR treatment strategies.

Downregulation of glycoprotein non-metastatic melanoma protein B prevents high glucose-induced angiogenesis in diabetic retinopathy

Diabetic retinopathy (DR), a microvascular complication characterized by abnormal angiogenesis, is the most common reason for irreversible blindness. Glycoprotein non-metastatic melanoma protein B (GPNMB), as a transmembrane protein, was found to be associated with angiogenesis. This study aims to investigate the role of GPNMB in DR. The levels of GPNMB and Integrin β1 were detected by real-time PCR and western blot and were found to be increased in human retinal microvascular endothelial cells (HRMECs) with high glucose (HG, 25 mmol/L) treatment. Knockdown of GPNMB was mediated by lentivirus carrying shRNA targeting GPNMB in vivo and in vitro. Functional experiments, including cell counting kit-8 (CCK-8), scratch, and tube formation assays, showed the anti-proliferative, anti-migrative, and anti-angiogenic roles of GPNMB knockdown in HRMECs using the lentivirus system following HG challenge. Additionally, increased GPNMB levels were detected in the retina of DR rats induced by a single intraperitoneal injection of streptozotocin (60 mg/kg) using real-time PCR, western blot, and immunofluorescence assays. Downregulation of GPNMB inhibited the angiogenesis and vascular endothelial growth factor production in the retina of rats with DR. Furthermore, overexpression of Integrin β1 led to increased angiogenesis in DR. Integrin β1 was indicated as a target protein of GPNMB. Upregulated-Integrin β1 restored GPNMB knockdown-induced inhibition of cell viability, migration, and tube formation in HRMECs. In conclusion, we provide evidence for the angiogenic role of GPNMB and demonstrate that silencing GPNMB may represent a therapeutic potential in the treatment of DR.

Senolytics in the treatment of diabetic retinopathy

Diabetic retinopathy (DR) is the most common complication of diabetes. DR is characterized by damage to retinal vasculature resulting in vision impairment and, if untreated, could eventually lead to blindness. The pathogenic mechanism of DR is complex; emerging studies suggest that premature senescence of retinal cells and subsequent secretion of inflammatory cytokines exacerbate DR disease state by stimulating paracrine senescence, pathological angiogenesis, and reparative vascular regeneration. Senolytics are a new class of drugs that can selectively clear out senescent cells from the retina, thus holding a significant promise in DR treatment and prevention. In this review, we discuss the critical role of cellular senescence in DR’s pathogenesis; A literature review was conducted in September of 2021 to explore the therapeutic potential of senolytics in the treatment of DR. Studies that were relevant to the research topic were selected through multiple keyword searches in the search engine, PubMed and thoroughly reviewed using abstracts and full-text articles. We present evidence from animal models for studying cellular senescence in DR and discuss multiple pathogenic mechanisms in cellular senescence and its involvement in DR. We also discuss the current state of pharmaceutical development at preclinical and clinical stages focusing on the senolytic drugs navitoclax, 17-DMAG, piperlongumine, UBX-1325, dasatinib quercetin, and fisetin. In particular, UBX-1325 holds a promising prospect for DR treatment based on the positive outcome of early clinical studies in individuals with diabetic macular edema (DME) and wet age-related macular degeneration.

Terrestrial health applications of visual assessment technology and machine learning in spaceflight associated neuro-ocular syndrome

The neuro-ocular effects of long-duration spaceflight have been termed Spaceflight Associated Neuro-Ocular Syndrome (SANS) and are a potential challenge for future, human space exploration. The underlying pathogenesis of SANS remains ill-defined, but several emerging translational applications of terrestrial head-mounted, visual assessment technology and machine learning frameworks are being studied for potential use in SANS. To develop such technology requires close consideration of the spaceflight environment which is limited in medical resources and imaging modalities. This austere environment necessitates the utilization of low mass, low footprint technology to build a visual assessment system that is comprehensive, accessible, and efficient. In this paper, we discuss the unique considerations for developing this technology for SANS and translational applications on Earth. Several key limitations observed in the austere spaceflight environment share similarities to barriers to care for underserved areas on Earth. We discuss common terrestrial ophthalmic diseases and how machine learning and visual assessment technology for SANS can help increase screening for early intervention. The foundational developments with this novel system may help protect the visual health of both astronauts and individuals on Earth.

Diabetic retinopathy screening and treatment through the Brazilian National Health Insurance

The current study aimed to investigate diabetic retinopathy (DR) screening and treatment coverages among diabetic patients evaluated through the Brazilian National Health Insurance from 2014 to 2019. The Brazilian Public Health System Information Database was used as the primary data source. DR screening coverage was calculated as the rate of procedures of clinical dilated fundus exam and color fundus photograph over the number of diabetic patients. DR treatment coverage was calculated as the rate of procedures of intravitreal injection, photocoagulation, and panretinal photocoagulation over the number of diabetic patients presumably in need of DR treatment. The overall screening coverage increased from 12.1% in 2014 to 21.2% in 2019 (p < 0.001) with substantial regional discrepancies so that North region was the only one with no changes along the period. The overall treatment coverage increased from 27.7% in 2014 to 44.1% in 2019, with Southeast and Midwest absorbing the demand for service from the North, Northeast and South. Despite an improvement along the past years, both screening and treatment coverages for DR in diabetes patients are ineffective in Brazil. Public health policies should address resources disparities throughout the country aiming to offer same healthcare conditions to patients regardless their geographic location.

Role of Autotaxin in High Glucose-Induced Human ARPE-19 Cells

Autotaxin (ATX) is an enzymatic with lysophospholipase D (lysoPLD) activity. We investigated the role of ATX in high glucose (HG)-induced human retinal pigment epithelial (ARPE-19) cells to explore the pathogenesis of diabetic retinopathy (DR). We performed a quantitative real-time polymerase chain reaction, Western blotting, immunocytochemistry, enzyme-linked immunosorbent assay, cell permeability assay, and transepithelial electrical resistance measurement in HG-induced ARPE-19 cells and compared their results with those of normal glucose and osmotic pressure controls. ATX expression and its lysoPLD activity, barrier function, and expression of vascular endothelial growth factor receptors VEGFR-1 and VEGFR-2 were downregulated, while fibrotic responses, cytoskeletal reorganization, and transforming growth factor-β expression were upregulated, in the HG group. Our results suggest that HG induces intracellular ATX downregulation, barrier dysfunction, and fibrosis, which are involved in early DR and can be targeted for DR treatment.

Oxidative Stress, Neuroinflammation and Neurodegeneration: The Chicken, the Egg and the Dinosaur

Neurodegenerative diseases are characterized by the progressive degeneration of the neuronal cells and their networks, hampering the function of the central or peripheral nervous system [...].

Correlation of Diabetic Disease Severity to Degree of Quadrant Asymmetry in En Face OCTA Metrics

Purpose

To determine if diabetic retinopathy (DR) severity affects quadrant asymmetry (QA) of optical coherence tomography angiography (OCTA) metrics differentially.

Methods

Ninety eyes (60 patients) with no diabetes mellitus (DM) (n = 39) or varying levels of DR (n = 51) had OCTA images (3 × 3 mm, Cirrus5000) acquired five times and averaged. The vessel length density (VLD) and perfusion density (PD) of the superficial retinal layer (SRL) and deep retinal layer (DRL) were measured. QA was defined as the maximum minus minimum value among four parafoveal Early Treatment Diabetic Retinopathy quadrants, and compared with DR severity by linear regression including fixed effects for each individual and eye.

Results

The mean patient age was 55.5 years (range, 24–88 years) and 60% were male. Comparing severe nonproliferative DR or proliferative DR versus no DM/DR eyes, QA was significantly higher for SRL VLD, and PD (+0.67 ± 0.16 and +0.014 ± 0.003; P < 0.001) and DRL VLD, and PD (+1.25 ± 0.16 and +0.032 ± 0.003; P < 0.001). When comparing mild or moderate nonproliferative DR versus no DM/DR, the DRL VLD, and PD were significantly higher (+0.51 ± 0.13 and +0.015 ± 0.003; P < 0.001). For every step increase in DR severity, there was a +0.20 QA for SRL VLD, +0.004 SRL PD, +0.33 DRL VLD and +0.009 DRL PD (P < 0.001). Regression analysis comparing intraquadrant effect on DR severity demonstrated that the superior quadrant was most affected for all OCTA metrics.

Conclusions

DR severity affects VLD and PD more asymmetrically across Early Treatment Diabetic Retinopathy quadrants with a linear increase in QA for each worsening level of DR. Individual intraeye metrics such as QA can accurately quantify DR severity without concerns for intereye variabilities that could affect the reproducibility and reliability of OCTA quantification.

Prevalence, characteristics and risk factors of diabetic retinopathy in type 2 diabetes mellitus patients in Jordan: a cross-sectional study

Objectives

To measure the prevalence of diabetic retinopathy in patients with type 2 diabetes, to define their characteristics, and identify the associated risk factors.

Methods

We performed a cross sectional study of 1316 adult patients with type 2 diabetes mellitus who attended an ophthalmology clinic. Demographic, clinical, and laboratory data were analyzed. Diabetic retinopathy (DR) was diagnosed using a complete ophthalmic evaluation, including a fundic examination. Two regression models were constructed to identify the risk factors associated with DR and the parameters associated with the stage of retinopathy.

Results

Men accounted for 774 (58.8%) of the participants. The prevalence of DR was 28.2% (371 participants). DR was significantly more common in participants who were ≥60 years old, were women, had had diabetes for >10 years, were taking insulin, were not taking metformin, had a body mass index >30 kg/m², were current smokers, or had a history of hypertension. Advanced stages of DR were more common in participants in the later stages of nephropathy and with albuminuria.

Conclusions

Poor glycemic control, smoking, and advanced diabetic kidney disease are most closely associated with retinopathy. Further longitudinal studies are necessary to identify the mechanisms underlying these relationships and to guide community-based interventions.

The Narrative Medicine Approach in the Treatment of Diabetic Macular Edema: An Italian Experience

The study retraces the healthcare pathway of patients affected by diabetic macular edema (DME) through the direct voice of patients and caregivers by using a “patient journey” and narrative method approach. The mapping of the patient’s journey was developed by a multidisciplinary board of health professionals and involved four Italian retina centers. DME patients on intravitreal injection therapy and caregivers were interviewed according to the narrative medicine approach. Narratives were analyzed through a quali-quantitative tool, as set by the narrative medicine method. The study involved four specialized retina centers in Italy and collected a total of 106 narratives, 82 from DME patients and 24 from caregivers. The narratives reported their difficulty in identifying the correct pathway of care because of a limited awareness of diabetes and its complications. Patients experienced reduced autonomy due to ocular complications. In the treatment of diabetes and its complications, a multidisciplinary approach currently appears to be missing. DME reduces the quality of life of affected patients. The narrative medicine approach offers qualitative and emotional patient-guided information. The patient journey provides all of those involved in the management of DME with flowcharts to refer to, identifying the critical points in the healthcare journey of DME patients to improve the management of the disease.

Advances in cell therapies using stem cells/progenitors as a novel approach for neurovascular repair of the diabetic retina

BACKGROUND

Diabetic retinopathy, a major complication of diabetes mellitus, is a leading cause of sigh-loss in working age adults. Progressive loss of integrity of the retinal neurovascular unit is a central element in the disease pathogenesis. Retinal ischemia and inflammatory processes drive interrelated pathologies such as blood retinal barrier disruption, fluid accumulation, gliosis, neuronal loss and/or aberrant neovascularisation. Current treatment options are somewhat limited to late-stages of the disease where there is already significant damage to the retinal architecture arising from degenerative, edematous and proliferative pathology. New preventive and interventional treatments to target early vasodegenerative and neurodegenerative stages of the disease are needed to ensure avoidance of sight-loss.

MAIN BODY

Historically, diabetic retinopathy has been considered a primarily microvascular disease of the retina and clinically it is classified based on the presence and severity of vascular lesions. It is now known that neurodegeneration plays a significant role during the pathogenesis. Loss of neurons has been documented at early stages in pre-clinical models as well as in individuals with diabetes and, in some, even prior to the onset of clinically overt diabetic retinopathy. Recent studies suggest that some patients have a primarily neurodegenerative phenotype. Retinal pigment epithelial cells and the choroid are also affected during the disease pathogenesis and these tissues may also need to be addressed by new regenerative treatments. Most stem cell research for diabetic retinopathy to date has focused on addressing vasculopathy. Pre-clinical and clinical studies aiming to restore damaged vasculature using vasoactive progenitors including mesenchymal stromal/stem cells, adipose stem cells, CD34+ cells, endothelial colony forming cells and induced pluripotent stem cell derived endothelial cells are discussed in this review. Stem cells that could replace dying neurons such as retinal progenitor cells, pluripotent stem cell derived photoreceptors and ganglion cells as well as Müller stem cells are also discussed. Finally, challenges of stem cell therapies relevant to diabetic retinopathy are considered.

CONCLUSION

Stem cell therapies hold great potential to replace dying cells during early and even late stages of diabetic retinopathy. However, due to the presence of different phenotypes, selecting the most suitable stem cell product for individual patients will be crucial for successful treatment.

Automated multidimensional deep learning platform for referable diabetic retinopathy detection: a multicentre, retrospective study

OBJECTIVE

To develop and validate a real-world screening, guideline-based deep learning (DL) system for referable diabetic retinopathy (DR) detection.

DESIGN

This is a multicentre platform development study based on retrospective, cross-sectional data sets. Images were labelled by two-level certificated graders as the ground truth. According to the UK DR screening guideline, a DL model based on colour retinal images with five-dimensional classifiers, namely image quality, retinopathy, maculopathy gradability, maculopathy and photocoagulation, was developed. Referable decisions were generated by integrating the output of all classifiers and reported at the image, eye and patient level. The performance of the DL was compared with DR experts.

SETTING

DR screening programmes from three hospitals and the Lifeline Express Diabetic Retinopathy Screening Program in China.

PARTICIPANTS

83 465 images of 39 836 eyes from 21 716 patients were annotated, of which 53 211 images were used as the development set and 30 254 images were used as the external validation set, split based on centre and period.

MAIN OUTCOMES

Accuracy, F1 score, sensitivity, specificity, area under the receiver operating characteristic curve (AUROC), area under the precision-recall curve (AUPRC), Cohen's unweighted κ and Gwet's AC1 were calculated to evaluate the performance of the DL algorithm.

RESULTS

In the external validation set, the five classifiers achieved an accuracy of 0.915-0.980, F1 score of 0.682-0.966, sensitivity of 0.917-0.978, specificity of 0.907-0.981, AUROC of 0.9639-0.9944 and AUPRC of 0.7504-0.9949. Referable DR at three levels was detected with an accuracy of 0.918-0.967, F1 score of 0.822-0.918, sensitivity of 0.970-0.971, specificity of 0.905-0.967, AUROC of 0.9848-0.9931 and AUPRC of 0.9527-0.9760. With reference to the ground truth, the DL system showed comparable performance (Cohen's κ: 0.86-0.93; Gwet's AC1: 0.89-0.94) with three DR experts (Cohen's κ: 0.89-0.96; Gwet's AC1: 0.91-0.97) in detecting referable lesions.

CONCLUSIONS

The automatic DL system for detection of referable DR based on the UK guideline could achieve high accuracy in multidimensional classifications. It is suitable for large-scale, real-world DR screening.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Development of Fenofibrate/Randomly Methylated β-Cyclodextrin-Loaded Eudragit® RL 100 Nanoparticles for Ocular Delivery

Fenofibrate (FE) has been shown to markedly reduce the progression of diabetic retinopathy and age-related macular degeneration in clinical trials and animal models. Owing to the limited aqueous solubility of FE, it may hamper ocular bioavailability and result in low efficiency to treat such diseases. To enhance the solubility of FE, water-soluble FE/cyclodextrin (CD) complex formation was determined by a phase-solubility technique. Randomly methylated-β-CD (RMβCD) exhibited the best solubility and the highest complexation efficiency (CE) for FE. Additionally, water-soluble polymers (i.e., hydroxypropyl methyl cellulose and polyvinyl alcohol [PVA]) enhanced the solubility of FE/RMβCD complexes. Solid- and solution-state characterizations were performed to elucidate and confirm the formation of inclusion FE/RMβCD complex. FE-loaded Eudragit^® nanoparticle (EuNP) dispersions and suspensions were developed. The physicochemical properties (i.e., pH, osmolality, viscosity, particle size, size distribution, and zeta potential) were within acceptable ranges. Moreover, in vitro mucoadhesion, in vitro release, and in vitro permeation studies revealed that the FE-loaded EuNP eye drop suspensions had excellent mucoadhesive properties and sustained FE release. The hemolytic activity, hen’s egg test on chorioallantoic membrane assay, and in vitro cytotoxicity test showed that the FE formulations had low hemolytic activity, were cytocompatible, and were moderately irritable to the eyes. In conclusion, PVA-stabilized FE/RMβCD-loaded EuNP eye drop suspensions were successfully developed, warranting further in vivo testing.

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

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

The association between the use of sodium glucose cotransporter 2 inhibitor and the risk of diabetic retinopathy and other eye disorders: a systematic review and meta-analysis

OBJECTIVE

To assess the association between the use of sodium-glucose cotransporter 2 inhibitor (SGLT2i) and the incidence of diabetic retinopathy (DR).

RESEARCH DESIGN AND METHODS

Pubmed, Medline, Embase, the Cochrane Central Register of Controlled Trials and Clinicaltrial.gov were searched from inception to October 2021. Randomized controlled trials (RCTs) with reports of incidence of DR and other eye disorders between SGLT2i users and non-SGLT2i users with type 2 diabetes mellitus were included.

RESULTS

In general, the incidences of DR were comparable between SGLT2i users and non-SGLT2i users (OR=0.80, 95%CI 0.61 to 1.06, P=0.12). However, compared with non-SGLT2i users, the incidence of DR was significantly reduced in SGLT2i users with diabetes duration less than 10 years (OR=0.32, 95%CI 0.13 to 0.76, P=0.01). Weight reduction in SGLT2i users was associated with the decreased risk of retinal detachment. Moreover, longer study duration was associated with lower incidence of cataract and retinal vasculopathy in SGLT2i users.

CONCLUSIONS

In general, the use of SGLT2i was not associated with the incidence of DR. However, a reduced risk of DR was observed in SGLT2i users with diabetes duration less than 10 years. An early initiation of SGLT2i might be more likely to provide with ocular benefits.

Age-Related Eye Diseases in Individuals With Mild Cognitive Impairment and Alzheimer's Disease

Introduction

Alzheimer's disease (AD) and age-related eye diseases pose an increasing burden as the world's population ages. However, there is limited understanding on the association of AD/cognitive impairment, no dementia (CIND) with age-related eye diseases.

Methods

In this cross-sectional, memory clinic-based study of multiethnic Asians aged 50 and above, participants were diagnosed as AD (n = 216), cognitive impairment, no dementia (CIND) (n = 252), and no cognitive impairment (NCI) (n = 124) according to internationally accepted criteria. Retinal photographs were graded for the presence of age-related macular degeneration (AMD) and diabetic retinopathy (DR) using standard grading systems. Multivariable-adjusted logistic regression models were used to determine the associations between neurological diagnosis and odds of having eye diseases.

Results

Over half of the adults had at least one eye disease, with AMD being the most common (60.1%; n = 356), followed by DR (8.4%; n = 50). After controlling for age, sex, race, educational level, and marital status, persons with AD were more likely to have moderate DR or worse (OR = 2.95, 95% CI = 1.15–7.60) compared with NCI. In the fully adjusted model, the neurological diagnosis was not associated with AMD (OR = 0.75, 95% CI = 0.45–1.24).

Conclusion

Patients with AD have an increased odds of having moderate DR or worse, which suggests that these vulnerable individuals may benefit from specific social support and screening for eye diseases.

Implications of Diabetes-Induced Altered Metabolites on Retinal Neurodegeneration

Diabetic retinopathy (DR) is one of the major complications of diabetic eye diseases, causing vision loss and blindness worldwide. The concept of diabetic retinopathy has evolved from microvascular disease into more complex neurovascular disorders. Early in the disease progression of diabetes, the neuronal and glial cells are compromised before any microvascular abnormalities clinically detected by the ophthalmoscopic examination. This implies understanding the pathophysiological mechanisms at the early stage of disease progression especially due to diabetes-induced metabolic alterations to damage the neural retina so that early intervention and treatments options can be identified to prevent and inhibit the progression of DR. Hyperglycemia has been widely considered the major contributor to the progression of the retinal damage, even though tight control of glucose does not seem to have a bigger effect on the incidence or progression of retinal damage that leads to DR. Emerging evidence suggests that besides diabetes-induced hyperglycemia, dyslipidemia and amino acid defects might be a major contributor to the progression of early neurovascular retinal damage. In this review, we have discussed recent advances in the alterations of key metabolites of carbohydrate, lipid, and amino acids and their implications for neurovascular damage in DR.

A Multicenter Clinical Study of the Automated Fundus Screening Algorithm

Purpose

To evaluate the effectiveness of automated fundus screening software in detecting eye diseases by comparing the reported results against those given by human experts.

Results

There were 1585 subjects who completed the procedure and yielded qualified images. The prevalence of referable diabetic retinopathy (RDR), glaucoma suspect (GCS), and referable macular diseases (RMD) were 20.4%, 23.2%, and 49.0%, respectively. The overall sensitivity values for RDR, GCS, and RMD diagnosis are 0.948 (95% confidence interval [CI], 0.918-0.967), 0.891 (95% CI, 0.855-0.919), and 0.901 (95% CI-0.878, 0.920), respectively. The overall specificity values for RDR, GCS, and RMD diagnosis are 0.954 (95% CI, 0.915-0.965), 0.993 (95% CI-0.986, 0.996), and 0.955 (95% CI-0.939, 0.968), respectively.

Methods

We prospectively enrolled 1743 subjects at seven hospitals throughout China. At each hospital, an operator records the subjects' information, takes fundus images, and submits the images to the Image Reading Center of Zhongshan Ophthalmic Center, Sun Yat-Sen University (IRC). The IRC grades the images according to the study protocol. Meanwhile, these images will also be automatically screened by the artificial intelligence algorithm. Then, the analysis results of automated screening algorithm are compared against the grading results of IRC. The end point goals are lower bounds of 95% CI of sensitivity values that are greater than 0.85 for all three target diseases, and lower bounds of 95% CI of specificity values that are greater than 0.90 for RDR and 0.85 for GCS and RMD.

Conclusions

Automated fundus screening software demonstrated a high sensitivity and specificity in detecting RDR, GCS, and RMD from color fundus imaged captured using various cameras.

Translational Relevance

These findings suggest that automated software can improve the screening effectiveness for eye diseases, especially in a primary care context, where experienced ophthalmologists are scarce.

Clinical and Molecular Characteristics of Diabetic Retinopathy and Its Severity Complications among Diabetic Patients: A Multicenter Cross-Sectional Study

Background: Diabetic retinopathy (DR) is a complication associated with uncontrolled DM. It is a leading preventable cause of visual impairment in the world and a cause of blindness in those under 75 years old in developing countries. We aimed to explore the prevalence and associated risk factors of DR among diabetic patients in the West Bank. Materials and Methods:A quantitative multicenter cross-sectional study was conducted in all West Bank cities. Nearly, 385 patients underwent a comprehensive eye examination in addition to blood and urine tests. A previously validated questionnaire for ocular examination classification was used together with a socio-demographic and past medical history information sheet. Results: The prevalence of all DR in the West Bank was 41.8%. The prevalence of non-proliferative diabetic retinopathy (NPDR) was 50.3% (38.5% for mild NPDR, 10.6% for moderate NPDR and 1.2% for severe NPDR). The prevalence of proliferative diabetic retinopathy (PDR) was 9.9% and 39.7% for diabetic macular edema (DME) (17.4% for mild, 15.5% for moderate and 6.8% for severe DME). The prevalence of vision-threatening PDR and DME was 49.7% for both. In a univariate analysis, DR was significantly associated with body mass index; BMI (p = 0.035), DM duration (p = 0.002), Low-density lipoprotein (LDL) (p = 0.034), glutamic-oxaloacetic transaminase (GOT) level (p = 0.016) andblood urea (BU) (p = 0.044). A multivariate analysis showed a strong significant association between DR andpatients who had DM for 10-19years (adjusted odds ratio; AOR (95%CI); 1.843 (1.05–3.22)), abnormal levels of LDL (AOR (95%CI); 0.50 (0.30–0.83)), abnormal levels of GOT (AOR (95%CI); 0.49 (0.27–0.89)), and overweight (AOR (95%CI); 0.39 (0.19–0.80)). Conclusions: We found that the prevalence of DR in Palestine was higher than the global prevalence. Referral coordination between ophthalmologists and internal physicians is necessary to better follow up with DR patients. An interventional educational program by clinicians and public health professionals is recommended.

The Diagnostic Value of Circulating VEGF in Diabetic Retinopathy in Asia: A Systematic Review and Meta-analysis

PURPOSE

Vascular endothelial growth factor (VEGF) has obvious clinical value in diabetes, but the conclusions on the diagnostic value of diabetic retinopathy (DR) are not consistent. This study aims to comprehensively evaluate the accuracy of circulating VEGF in the diagnosis of DR in the Asian population by a method of meta-analysis.

METHODS

PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and China Wanfang Databases were searched for relevant studies on the diagnostic value of VEGF for DR in Asia up to November 2021. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and areas under the curve (AUC) were calculated by Stata 15.0 software.

RESULTS

After screening, eight eligible studies were enrolled, including 547 patients with DR. The results of the meta-analysis showed that the pooled DOR, sensitivity, specificity, PLR, and NLR were 31.67 (95%CI: 13.55 ~ 74.05), 0.86 (95%CI: 0.74 ~ 0.93), 0.84 (95%CI: 0.80 ~ 0.87), 5.33 (95%CI: 4.09 ~ 6.93), 0.17 (95%CI: 0.09 ~ 0.32), respectively. The AUC was 0.86 (95%CI: 0.82 ~ 0.89).

CONCLUSION

Circulating VEGF has a good diagnostic value in DR in the Asian population, with the potential to be an early diagnostic marker for DR.

Early retinal functional alteration in relation to diabetes duration in patients with type 2 diabetes without diabetic retinopathy

To examine the retinal structure and function in relation to diabetes duration and glycemia in patients without diabetic retinopathy (DR). 85 adults with type 2 diabetes without DR or macular edema underwent dilated indirect ophthalmoscopy, optical coherence tomography (OCT), ultra-wide field fundus photography, multifocal electroretinography (mfERG) and HbA_1C assessment. Patients were stratified as those with diabetes duration < 10 years and ≥ 10 years. Right eyes of all participants were analyzed. mfERG was analysed as ring 12, 34, 56. No significant differences were noted in OCT-derived retinal thickness measures between groups. mfERG P1 latencies were delayed, and amplitudes (nV/deg²) were reduced in all three rings in those with diabetes duration ≥ 10 years vs. < 10 years, with significant correlations to diabetes duration in all rings. Logistic regression showed that duration of diabetes ≥ 10 years was associated with greater age (odds ratio (OR) 1.081, 95% CI 1.022, 1.143) and lower P1 amplitudes in the middle ring (OR 0.924, 95% CI 0.854, 0.999). No significant correlations were observed between HbA_1c and retinal measures. In the absence of DR, early retinal functional alterations are detectable on mfERG in patients with longer diabetes duration, but with no difference in OCT-derived retinal thickness.

Biscuit consumption and diabetic retinopathy incidence in adults in the United States

BACKGROUND

Foods have a considerable influence on human health and were directly related to glycemic control for diabetes patients. However, little is known about the effects of biscuits, a traditional food consumed in large amounts in several countries, on diabetic retinopathy. This study aimed to explore the association between biscuit consumption and diabetic retinopathy prevalence in adults of the United States population.

METHODS

A cross-sectional study with 1904 participants from the National Health and Nutrition Examination Survey database were included in this population-based, cross-sectional study. The association between different consumption frequencies of biscuit and diabetic retinopathy prevalence was evaluated using a binary logistic regression model. Trend test, stratified and interaction analyses were also performed.

RESULTS

After possible confounders including sex, age, ethnicity, education, marital status, family poverty income ratio, smoking and alcohol consumption habit, fasting blood glucose level, hemoglobin A1c level, diagnosis of diabetes, insulin use, blood pressure, body mass index were adjusted, the participants who consumed biscuit 1-11 times a year, 1-3 times a month, and more than once a week had a 139.8% (95% confidence interval, 1.003-5.734), 182.1% (95% confidence interval, 1.106-7.191), and 236.2% (95% confidence interval, 1.335-9.844) higher risk of diabetic retinopathy prevalence, respectively, compared with those who never ate biscuit. For male, non-Hispanic, and overweight (body mass index ≥ 25 kg/m²) subgroups, the trend test demonstrated that the diabetic retinopathy prevalence significantly elevated with increased frequency of biscuit consumption (P _trend = 0.021, 0.009, and 0.002, respectively). The interaction analysis suggested that no aforementioned confounders played an interactive role in the relationship between biscuit consumption and diabetic retinopathy prevalence.

CONCLUSIONS

The risk of diabetic retinopathy was positively associated with biscuit consumption. Moreover, for male, non-Hispanic, or overweight individuals, the risk of diabetic retinopathy significantly increased with the frequency of biscuit consumption.

An analysis of the correlation between diabetic retinopathy and preretinal oxygen tension using three-dimensional spoiled gradient-recalled echo sequence imaging

BACKGROUND

The aims of this study were to evaluate the levels of preretinal oxygen tension in patients with diabetes who did not have hypertension by using three-dimensional spoiled gradient-recalled (3D-SPGR) echo sequence imaging and to explore the correlation between diabetic retinopathy (DR) and changes in preretinal oxygen tension.

METHOD

This study involved 15 patients with type 2 diabetes without hypertension, who were divided into a diabetic retinopathy (DR) group (n = 10 eyes) and a diabetic non-retinopathy (NDR) group (n = 20 eyes), according to the results of a fundus photography test. Another healthy control group (n = 14 eyes) also participated in the study. The preretinal vitreous optic disc area, nasal side, and temporal side signal intensity of the eyes was assessed before and after oxygen inhalation with the use of 3D-SPGR echo magnetic resonance imaging (MRI). The signal acquisition time was 10, 20, 30, 40, and 50 min after oxygen inhalation.

RESULTS

The results showed that, in the DR and NDR groups, the preretinal vitreous oxygen tension increased rapidly at 10 min after oxygen inhalation and peaked at 30-40 min, and the increased slope of the DR group was higher than that of the NDR group. The oxygen tension of the preretinal vitreous gradually increased after oxygen inhalation, and the difference between the DR and NDR groups and the control group was statistically significant (P < 0.05). The preretinal vitreous oxygen tension was higher in the optic disc, temporal side, and nasal side in the NDR group than in the control group, and the difference was statistically significant (P < 0.05). The maximum slope ratios of the optic disc and the temporal side of the DR group were greater than those of the control group, and the difference was statistically significant (P < 0.05).

CONCLUSION

Three-dimensional-SPGR echo MRI sequencing technology is useful for detecting preretinal oxygen tension levels in patients with diabetes. It can be used as one of the functional and imaging observation indicators for the early diagnosis of DR.

Experiment-Based Interventions to Diabetic Retinopathy: Present and Advances

Diabetic retinopathy is the major blinding disease among working-age populations, which is becoming more significant due to the growth of diabetes. The metabolic-induced oxidative and inflammatory stress leads to the insult of neovascular unit, resulting in the core pathophysiology of diabetic retinopathy. Existing therapies focus on the inflammation, oxidation, and angiogenesis phenomena of diabetic retinopathy, without effect to radically cure the disease. This review also summarizes novel therapeutic attempts for diabetic retinopathy along with their advantages and disadvantages, mainly focusing on those using cellular and genetic techniques to achieve remission on a fundamental level of disease.

A Mechanistic Exploratory Study on the Therapeutic Efficacy of Astragaloside IV Against Diabetic Retinopathy Revealed by Network Pharmacology

Purpose: Diabetic retinopathy (DR) is a serious complication of diabetes mellitus, which nearly happens to all the diabetic sufferers. This study aims to identify the preliminary molecular regulation involved in the therapeutic efficacy of astragaloside IV (AS- IV) for DR.

Methods: Diabetic rat models were established and treated with AS-IV. Optical coherence tomography (OCT) and Hematoxylin-eosin (HE) staining was employed to demonstrate the histopathological changes. The main targets of AS-IV were identified by searching from public databases of traditional Chinese medicine (GeneCards, PharmMapper and Swiss Target Prediction). Besides, disease targets of DR were also obtained by integrated data from GEO datasets and predicted from public databases. Protein-protein interaction (PPI) network was constructed by Cytoscape with overlapping genes and 10 core targets were selected, on which Gene Ontology (GO) along with Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted. The interaction between AS-IV and these crucial genes were analyzed using molecular docking. RT-qPCR and western blot were used to verify the expression variation of core targets.

Results: OCT imaging and HE staining demonstrated that AS-IV administration significantly increased retinal thickness in diabetic rats, obviously alleviating DR induced histopathological changes as well as elevated blood glucose levels. 107 common targets of AS-IV and DR were determined after intersection. PPI network analysis filtered 10 hub genes potentially targeted by AS-IV, including VEGFA, CASP3, HIF1α, STAT3, CTNNB1, SRC, AKT1, EGFR, IL1β and IL6. Enrichment analysis indicated that these genes were mainly enriched in biological processes like T cell activation, epithelial cell proliferation and protein kinase B signaling, and involved in oxidative stress, apoptosis and inflammation-related pathways. The molecular docking prediction suggested that AS-IV exhibited stable binding to these core targets. In addition, mRNA levels of core targets in diabetic rats were differentially expressed before and after AS-IV treatment. Western blot further revealed that AS-IV treatment elevated DR-depressed protein levels of PI3K and AKT.

Conclusion: Our study elucidated the effect of AS-IV in attenuating retinopathy induced by diabetes in rats and preliminarily unveiled the therapeutic efficacy of AS-IV in the treatment of DR might be attributed to activation of PI3K-AKT signaling pathway.

Association Between Increased Lipid Profiles and Risk of Diabetic Retinopathy in a Population-Based Case-Control Study

Purpose

We aimed to investigate the association between lipid profiles and diabetic retinopathy (DR).

Patients and Methods

This case-control study, which was conducted between November 2019 and August 2021, comprised 309 patients with DR, 186 patients with diabetes mellitus, and 172 healthy controls. Serum cholesterol (CHOL), triglyceride (TRIG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), small dense LDL-C (SDLDL-C), apolipoprotein A (APOA), APOB, APOE and lipoprotein (a)(LPA) levels were assessed. Patients were divided into two groups according to median age and glycated hemoglobin (HbA1c) level. Linear and logistic regression analyses were performed to assess the association between lipid levels and DR.

Results

CHOL, TRIG, HDL-C, APOB, APOE, and SDLDL-C levels were significantly higher in the DR group than in the healthy control group, and TRIG levels were lower in the DR group than in the DM group (P < 0.05), especially in the ≤57-year-old and the HbA1c ≤7.2% subgroups. Linear regression analyses showed that CHOL, TRIG, APOA, APOB, APOE, and SDLDL-C levels were associated with HbA1c levels. Multivariable logistic regression analyses indicated that CHOL (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.112–1.566), TRIG (OR = 1.269, 95% CI = 1.030–1.563), HDL-C (OR = 43.744, 95% CI = 17.12–111.769), APOB (OR = 7.037, 95% CI = 3.370–14.695), APOE (OR = 1.057, 95% CI = 1.038–1.077), and SDLDL-C (OR = 14.719, 95% CI = 8.304–26.088) levels were risk factors for DR (P < 0.05).

Conclusion

Increased lipid levels were risk factors for DR, and lipid level control should be strengthened, especially in younger adults or in patients with HbA1c ≤7.2%.

The correlation between serum albumin and diabetic retinopathy among people with type 2 diabetes mellitus: NHANES 2011–2020

Objectives

The objective of this research aimed to investigate the correlation involving serum albumin with diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM).

Methods

From 2011 to 2020, the National Health and Nutrition Examination Survey (NHANES) surveyed 45462 participants. We used the relevant data to conduct descriptive statistics, linear regression, and Logistic regression analysis.

Results

After adjusting for age, sex, and race, as well as all other variables, serum albumin was significantly negatively related to DR (P<0.001). Furthermore, after controlling for confounding factors, the third quartile (Q3) and the fourth quartile (Q4) had quite a negative significant relationship with the incidence of DR (P<0.01). The second quartile had a significant positive correlation with DR, whereas the observed negative correlations were not statistically meaningful (P>0.05).

Conclusion

Albumin levels in the serum have a quantitatively significant negative correlation with DR. Serum albumin levels in the blood can be used as a reference point for protracted follow-up of people with T2DM.

Visual outcomes of observation, macular laser and anti-VEGF in diabetic macular edema in type 1 diabetes: a real-world study

Background

The treatment for diabetic macular edema (DME) has revolutionized during the last 15 years after the introduction of intravitreal anti-VEGF agents. The aim of the current study is to evaluate the real-world visual outcomes of diabetic macular edema (DME) treatment in patients with type 1 diabetes (T1D) in long-term follow-up.

Methods

A real-world, descriptive, population-based cohort and follow-up of all patients with T1D and DME in 2006-2020 in 34 communities of the Northern Ostrobothnia Hospital District. The main outcome measures included age, gender, duration of T1D at the onset of DME, stage of retinopathy, treatment of DME (observation, laser, intravitreal treatments, combination), and visual outcomes.

Results

A total of 304 eyes of 206 T1D patients with DME were included. 75% (n=155) had non-proliferative diabetic retinopathy during the onset of DME. 15% of the cases were observed, 33% had macular laser, 41% intravitreal anti-VEGF and 12% combination of laser and intravitreal injections. Patients in anti-VEGF and in combination groups gained 4.9 and 5.5 ETDRS letters after the initial DME episode (p<0.001 and p<0.001), and the long-term visual improvements were 4.1 and 5.1 ETDRS letters (p<0.001 and p<0.001), respectively. In observation and laser groups the initial gain of 0.1 (p>0.90) and loss of 0.4 ETDRS letter (p=0.61), respectively, was noted. After the follow-up, a 3.7 ETDRS letter decrease was documented in the observation group (p>0.90) and a 1.1 (p=0.14) ETDRS letter decline in the laser group of patients. At the beginning of treatment, eyes subjected to anti-VEGF alone or in combination with laser had lower visual acuity compared to eyes subjected to observation or macular laser. The average of a 6.1±4.8 anti-VEGF injections were needed to dry DME. Visual impairment due to DME decreased from 2.4% to 1.0% during the 15-year period.

Conclusions

Anti-VEGF alone or in combination with macular laser seems to be beneficial in terms of visual outcomes and treatment stability in T1D patients with central DME.

Moreover, satisfying long-term visual outcomes were achieved with anti-VEGF treatment in a real-world setting.

Redoxisome and diabetic retinopathy: Pathophysiology and therapeutic interventions

Diabetic retinopathy (DR) is a chronic microvascular complication of diabetes mellitus (DM). It is a worldwide growing epidemic disease considered to be the leading cause of vision-loss and blindness in people with DM. Redox reactions occurring at the extra- and intracellular levels are essential for the maintenance of cellular homeostasis. Dysregulation of redox homeostasis are implicated in the onset and development of DR. Thioredoxin1 (TRX1) and Thioredoxin2 (TRX2) are cytoplasmic and mitochondrially localized antioxidant proteins ubiquitously expressed in various cells and control cellular reactive oxygen species (ROS) by reducing the disulfides into thiol groups. Thioredoxin-interacting protein (TXNIP) binds to TRX system and inhibits the active reduced form of TRX through disulfide exchange reaction. Recent studies indicate the association of TRX/TXNIP with redox signal transduction pathways including activation of Nod-like receptor pyrin domain containing protein-3 (NLRP3) inflammasome, apoptosis, autophagy/mitophagy, epigenetic modifications in a redox-dependent manner. Thus, it is important to gain a more in-depth understanding about the cellular and molecular mechanisms that links redoxisome and ER/Mitochondrial dysfunction to drive the progression of DR. The purpose of this review is to provide a mechanistic understanding of the complex molecular mechanisms and pathophysiological roles associated with redoxisome, the TRX/TXNIP redox signaling complex under oxidative stress in the development of DR. Also, the molecular targets of FDA approved drugs and clinical trials in addition to effective antioxidant strategies for the treatment of diabetic retinopathy are reviewed.