Mechanism of worsening diabetic retinopathy with rapid lowering of blood glucose: the synergistic hypothesis

Targeting pericyte retention in Diabetic Retinopathy: a review

Diabetic retinopathy is a common yet severe complication of diabetes mellitus and is the leading cause of blindness in middle-aged adults. After years of poorly managed hyperglycemia, complications begin as non-proliferative diabetic retinopathy but can then progress into the proliferative stage marked by neovascularization of the retina. Multiple pathologic mechanisms caused by chronic hyperglycemia damage the retinal vasculature leading to pericyte drop out and the progression of the disease. This review outlines the major pathways of pathogenesis in diabetic retinopathy, highlighting the protective role pericytes play in preserving the blood-retinal barrier. Given the loss of this cell line is a defining feature of the disease, ways in which to prevent pericyte dropout within retinal vasculature is discussed, targeting various pathogenesis pathways of diabetic retinopathy.

Comparison of Machine Learning Algorithms and Nomogram Construction for Diabetic Retinopathy Prediction in Type 2 Diabetes Mellitus Patients

INTRODUCTION

The aim of this study was to compare various machine learning algorithms for constructing a diabetic retinopathy (DR) prediction model among type 2 diabetes mellitus (DM) patients and to develop a nomogram based on the best model.

METHODS

This cross-sectional study included DM patients receiving routine DR screening. Patients were randomly divided into training (244) and validation (105) sets. Least absolute shrinkage and selection operator regression was used for the selection of clinical characteristics. Six machine learning algorithms were compared: decision tree (DT), k-nearest neighbours (KNN), logistic regression model (LM), random forest (RF), support vector machine (SVM), and XGBoost (XGB). Model performance was assessed via receiver-operating characteristic (ROC), calibration, and decision curve analyses (DCAs). A nomogram was then developed on the basis of the best model.

RESULTS

Compared with the five other machine learning algorithms (DT, KNN, RF, SVM, and XGB), the LM demonstrated the highest area under the ROC curve (AUC, 0.894) and recall (0.92) in the validation set. Additionally, the calibration curves and DCA results were relatively favourable. Disease duration, DPN, insulin dosage, urinary protein, and ALB were included in the LM. The nomogram exhibited robust discrimination (AUC: 0.856 in the training set and 0.868 in the validation set), calibration, and clinical applicability across the two datasets after 1,000 bootstraps.

CONCLUSION

Among the six different machine learning algorithms, the LM algorithm demonstrated the best performance. A logistic regression-based nomogram for predicting DR in type 2 DM patients was established. This nomogram may serve as a valuable tool for DR detection, facilitating timely treatment.

Prevalence of diabetic retinopathy and its risk factors in rural patients with type 2 diabetes referring to Beijing Huairou Hospital, China

BACKGROUND

China has the largest population of diabetic patients worldwide. A diverse population and regional discrepancy in access to health care and diabetes management may lead to unique risk factors for diabetic retinopathy (DR) in different regions of China. This study aimed to evaluate the prevalence and risk factors of DR in rural patients with type 2 diabetes.

METHODS

This hospital-based cross-sectional study recruited a sample of 704 type 2 diabetic patients from rural areas referred to Beijing Huairou Hospital, China, from June 1, 2022, to June 1, 2023. The medical history, demographic information, and results of laboratory examinations of patients were collected and analyzed. The diagnosis of DR were performed by experienced ophthalmologists using mydriatic fundus photography.

RESULTS

Out of all patients, 53.8% were male and 46.2% were female. The mean age of patients and duration of diabetes were 54.9 ± 13.0 and 6.2 ± 4.5 years, respectively. The DR prevalence was 16.8%. The independent risk factors for DR in multivariate analysis were diabetes duration > 10 years (OR = 9.16, 95%CI = 5.49-15.30), fasting plasma glucose ≥ 7.2 mmol/L (OR = 3.25, 95%CI = 1.42-7.42), glycosylated hemoglobin ≥ 7% (OR = 6.49, 95%CI = 2.59-16.23), hypertension (OR = 1.59, 95%CI = 1.05-2.40), hyperlipidemia (OR = 2.16, 95%CI = 1.30-3.59), diabetic nephropathy (OR = 1.95, 95%CI = 1.17-3.23), high uric acid level (OR = 3.57, 95%CI = 1.56-8.15), high albumin to creatinine ratio (OR = 2.48, 95%CI = 1.06-5.82), and insulin treatment (OR = 1.79, 95%CI = 1.12-2.88).

CONCLUSIONS

This study evaluated the DR prevalence and its associated risk factors among type 2 diabetic patients from rural areas in Beijing's Huairou District, China. Paying attention to these risk factors may be useful in screening high-risk diabetic patients for DR and adopting early preventive and therapeutic interventions.

Existing and emerging GLP-1 receptor agonist therapy: Ramifications for diabetic retinopathy screening

GLP-1 receptor agonist treatment revolutionised the management of type 2 diabetes mellitus with significant enhancement of cardiovascular risk reduction. They have been instrumental in effectively managing the glycaemic control of this at-risk patient group. This class of drugs are associated with rapid improvement in glucose levels and consequently, transient early worsening of pre-existing diabetic retinopathy (DR) which is well-recognised, but this paradox is less commonly perceived in routine clinical practice. The recent shortage of supply has resulted in an enforced hiatus to prescribing all existing GLP-1 receptor agonists, which is expected to last all through 2024. This becomes even more pertinent as their DR could have progressed due to worsening HbA1c as a result of the unforeseen interruption to GLP-1 receptor agonist treatment. Therefore, when these medications are recommenced in a few months' time, all prescribers need to be aware of these patients' most up-to-date DR status and liaise with their affiliated screening service.

Eye Diseases: When the Solution Comes from Plant Alkaloids

Plants are an incredible source of metabolites showing a wide range of biological activities. Among these, there are the alkaloids, which have been exploited for medical purposes since ancient times. Nowadays, many plant-derived alkaloids are the main components of drugs used as therapy for different human diseases. This review deals with providing an overview of the alkaloids used to treat eye diseases, describing the historical outline, the plants from which they are extracted, and the clinical and molecular data supporting their therapeutic activity. Among the different alkaloids that have found application in medicine so far, atropine and pilocarpine are the most characterized ones. Conversely, caffeine and berberine have been proposed for the treatment of different eye disorders, but further studies are still necessary to fully understand their clinical value. Lastly, the alkaloid used for managing hypertension, reserpine, has been recently identified as a potential drug for ameliorating retinal disorders. Other important aspects discussed in this review are different solutions for alkaloid production. Given that the industrial production of many of the plant-derived alkaloids still relies on extraction from plants, and the chemical synthesis can be highly expensive and poorly efficient, alternative methods need to be found. Biotechnologies offer a multitude of possibilities to overcome these issues, spanning from genetic engineering to synthetic biology for microorganisms and bioreactors for plant cell cultures. However, further efforts are needed to completely satisfy the pharmaceutical demand.

Transition probabilities of diabetic retinopathy and death in an Asian population with diabetes

PURPOSE

To evaluate the dynamic transitions in diabetic retinopathy (DR) severity over time and associated risk factors in an Asian population with diabetes.

DESIGN

Longitudinal cohort study METHODS: We analyzed data from 9481 adults in the Singapore Integrated Diabetic Retinopathy Screening Program (2010-2015) with linkage to death registry. A multistate Markov model adjusted for age, sex, systolic blood pressure (SBP), diabetes duration, HbA1c, and body mass index (BMI) was applied to estimate annual transition probabilities between four DR states (no, mild, moderate, and severe/proliferative) and death, and the mean sojourn time in each state.

RESULTS

The median assessment interval was 12 months, with most patients having 3 assessments. Annual probabilities for DR progression (no-to-mild, mild-to-moderate and moderate-to-severe/proliferative) were 6.1 %, 7.0 % and 19.3 %, respectively; and for regression (mild-to-no, moderate-to-mild and severe-to-moderate) were 55.4 %, 17.3 % and 4.4 %, respectively. Annual mortality rates from each DR state were 1.2 %, 2.0 %, 18.7 %, and 30.0 %. The sojourn time in each state were 8.2, 0.8, 0.8 and 2.2 years. Higher HbA1c and SBP levels were associated with progression of no-mild and mild-moderate DR, and diabetes duration with no-to-mild and moderate-to-severe/proliferative DR. Lower HbA1c levels were associated with regression from mild-to-no and moderate-to-mild, and higher BMI with mild-to-no DR.

CONCLUSIONS

Our results suggest a prolonged duration (∼8 years) in developing mild DR, with faster transitions (within a year) from mild or moderate states. Moderate/above DR greatly increases the probability of progression and death as compared to mild DR/below. HbA1c was associated with both progression as well as regression.

An analysis of the relationship between ABCC8 and KCNJ11 gene polymorphisms and diabetic retinopathy in Turkish population

BACKGROUND

Diabetic retinopathy (DR) occurs due to high blood glucose damage to the retina and leads to blindness if left untreated. KATP and related genes (KCNJ11 and ABCC8) play an important role in insulin secretion by glucose-stimulated pancreatic beta cells and the regulation of insulin secretion. KCNJ11 E23K (rs5219), ABCC8-3 C/T (rs1799854), Thr759Thr (rs1801261) and Arg1273Arg (rs1799859) are among the possible related single nucleotide polymorphisms (SNPs). The aim of this study is to find out how DR and these SNPs are associated with one another in the Turkish population.

MATERIALS AND METHODS

This study included 176 patients with type 2 diabetes mellitus without retinopathy (T2DM-rp), 177 DR patients, and 204 controls. Genomic DNA was extracted from whole blood, and genotypes were determined by the PCR-RFLP method.

RESULTS

In the present study, a significant difference was not found between all the groups in terms of Arg1273Arg polymorphism located in the ABCC8 gene. The T allele and the TT genotype in the -3 C/T polymorphism in this gene may have a protective effect in the development of DR (p = 0.036 for the TT genotype; p = 0.034 for T allele) and PDR (p = 0.042 and 0.025 for the TT genotype). The AA genotype showed a significant increase in the DR group compared to T2DM-rp in the KCNJ11 E23K polymorphism (p = 0.046).

CONCLUSIONS

Consequently, the T allele and TT genotype in the -3 C/T polymorphism of the ABCC8 gene may have a protective marker on the development of DR and PDR, while the AA genotype in the E23K polymorphism of the KCNJ11 gene may be effective in the development of DR in the Turkish population.

Acute worsening of microvascular complications of diabetes mellitus during rapid glycemic control: The pathobiology and therapeutic implications

While chronic hyperglycaemia resulting from poorly controlled diabetes mellitus (DM) is a well-known precursor to complications such as diabetic retinopathy, neuropathy (including autonomic neuropathy), and nephropathy, a paradoxical intensification of these complications can rarely occur with aggressive glycemic management resulting in a rapid reduction of glycated haemoglobin. Although, acute onset or worsening of retinopathy and treatment induced neuropathy of diabetes are more common among these complications, rarely other problems such as albuminuria, diabetic kidney disease, Charcot's neuroarthropathy, gastroparesis, and urinary bladder dysfunction are also encountered. The World Journal of Diabetes recently published a rare case of all these complications, occurring in a young type 1 diabetic female intensely managed during pregnancy, as a case report by Huret et al. It is essential to have a comprehensive understanding of the pathobiology, prevalence, predisposing factors, and management strategies for acute onset, or worsening of microvascular complications when rapid glycemic control is achieved, which serves to alleviate patient morbidity, enhance disease management compliance, and possibly to avoid medico-legal issues around this rare clinical problem. This editorial delves into the dynamics surrounding the acute exacerbation of microvascular complications in poorly controlled DM during rapid glycaemic control.

Identification of phytocompounds as potent inhibitors of sodium/glucose cotransporter-2 leading to diabetes treatment

Type-II diabetes, a major metabolic disorder has threatened the very existence of a healthy life since long ago. Commercially available antidiabetic drugs are known for several adverse effects. The present study attempted to identify potential phytocompounds as inhibitors of sodium/glucose cotransporter-2 (SGLT2), a major protein that helps in glucose re-absorption from renal tubules. A total of 28 phytocompounds were collected based on the literature survey. 3D co-ordinates of phytocompounds were collected from PubChem database. Molecular docking was carried out with SGLT2 protein and the best 3 docking complexes were subjected to molecular dynamics simulation for 100 ns. Free energy changes were also analyzed using MM/PBSA analysis. Phytocompounds were also analyzed for their drug-likeness and ADMET properties. Docking study observed a strong binding affinity of phytocompounds (> -7.0 kcal/mol). More than 10 phytocompounds showed better binding affinity compared to reference drugs. Further analysis of three best docking complexes when analyzed by MD simulation showed better stability and compactness of the complexes compared to reference drug, empagliflozin. MM/PBSA analysis also revealed that van der Waals force and electrostatic energy are the major binding energy involved in the complex formation. Like docking energy, free energy analysis also observed stronger binding energies (ΔGGAS) in SGLT2-phytocompound complexes compared to empagliflozin complex. All the phytocompounds showed drug-likeness and considerable ADMET properties. The study, therefore, suggests that Trifolirhizin-6'-monoacetate, Aspalathin, and Quercetin-3-glucoside could be a possible inhibitor of SGLT2 protein. However, further studies need to be carried out to reveal the exact mode of activity.Communicated by Ramaswamy H. Sarma.

Relaxation of mitochondrial hyperfusion in the diabetic retina via N6-furfuryladenosine confers neuroprotection regardless of glycaemic status

The recovery of mitochondrial quality control (MQC) may bring innovative solutions for neuroprotection, while imposing a significant challenge given the need of holistic approaches to restore mitochondrial dynamics (fusion/fission) and turnover (mitophagy and biogenesis). In diabetic retinopathy, this is compounded by our lack of understanding of human retinal neurodegeneration, but also how MQC processes interact during disease progression. Here, we show that mitochondria hyperfusion is characteristic of retinal neurodegeneration in human and murine diabetes, blunting the homeostatic turnover of mitochondria and causing metabolic and neuro-inflammatory stress. By mimicking this mitochondrial remodelling in vitro, we ascertain that N6-furfuryladenosine enhances mitochondrial turnover and bioenergetics by relaxing hyperfusion in a controlled fashion. Oral administration of N6-furfuryladenosine enhances mitochondrial turnover in the diabetic mouse retina (Ins2Akita males), improving clinical correlates and conferring neuroprotection regardless of glycaemic status. Our findings provide translational insights for neuroprotection in the diabetic retina through the holistic recovery of MQC.

Associations of antidiabetic drugs with diabetic retinopathy in people with type 2 diabetes: an umbrella review and meta-analysis

Background

Diabetic retinopathy (DR) is the most frequent complication of type 2 diabetes and remains the leading cause of preventable blindness. Current clinical decisions regarding the administration of antidiabetic drugs do not sufficiently incorporate the risk of DR due to the inconclusive evidence from preceding meta-analyses. This umbrella review aimed to systematically evaluate the effects of antidiabetic drugs on DR in people with type 2 diabetes.

Methods

A systematic literature search was undertaken in Medline, Embase, and the Cochrane Library (from inception till 17th May 2022) without language restrictions to identify systematic reviews and meta-analyses of randomized controlled trials or longitudinal studies that examined the association between antidiabetic drugs and DR in people with type 2 diabetes. Two authors independently extracted data and assessed the quality of included studies using the AMSTAR-2 (A MeaSurement Tool to Assess Systematic Reviews) checklist, and evidence assessment was performed using the GRADE (Grading of recommendations, Assessment, Development and Evaluation). Random-effects models were applied to calculate relative risk (RR) or odds ratios (OR) with 95% confidence intervals (CI). This study was registered with PROSPERO (CRD42022332052).

Results

With trial evidence from 11 systematic reviews and meta-analyses, we found that the use of glucagon-like peptide-1 receptor agonists (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), or dipeptidyl peptidase-4 inhibitors (DPP-4i) was not statistically associated with the risk of DR, compared to either placebo (RR: GLP-1 RA, 0.98, 0.89-1.08; SGLT-2i, 1.00, 95% CI 0.79-1.27; DPP-4i, 1.17, 0.99-1.39) or other antidiabetic drugs. Compared to other antidiabetic drugs, meglitinides (0.34, 0.01-8.25), SGLT-2i (0.73, 0.10-5.16), thiazolidinediones (0.92, 0.67-1.26), metformin (1.15, 0.81-1.63), sulphonylureas (1.24, 0.93-1.65), and acarbose (4.21, 0.44-40.43) were not statistically associated with the risk of DR. With evidence from longitudinal studies only, insulin was found to have a higher risk of DR than other antidiabetic drugs (OR: 2.47, 95% CI: 2.04-2.99).

Conclusion

Our results indicate that antidiabetic drugs are generally safe to prescribe regarding the risk of DR among people with type 2 diabetes. Further robust and large-scale trials investigating the effects of insulin, meglitinides, and acarbose on DR are warranted.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=332052, identifier CRD42022332052.

The ideal treatment timing for diabetic retinopathy: the molecular pathological mechanisms underlying early-stage diabetic retinopathy are a matter of concern

Diabetic retinopathy (DR) is a prevalent complication of diabetes, significantly impacting patients' quality of life due to vision loss. No pharmacological therapies are currently approved for DR, excepted the drugs to treat diabetic macular edema such as the anti-VEGF agents or steroids administered by intraocular route. Advancements in research have highlighted the crucial role of early intervention in DR for halting or delaying disease progression. This holds immense significance in enhancing patients' quality of life and alleviating the societal burden associated with medical care costs. The non-proliferative stage represents the early phase of DR. In comparison to the proliferative stage, pathological changes primarily manifest as microangiomas and hemorrhages, while at the cellular level, there is a loss of pericytes, neuronal cell death, and disruption of components and functionality within the retinal neuronal vascular unit encompassing pericytes and neurons. Both neurodegenerative and microvascular abnormalities manifest in the early stages of DR. Therefore, our focus lies on the non-proliferative stage of DR and we have initially summarized the mechanisms involved in its development, including pathways such as polyols, that revolve around the pathological changes occurring during this early stage. We also integrate cutting-edge mechanisms, including leukocyte adhesion, neutrophil extracellular traps, multiple RNA regulation, microorganisms, cell death (ferroptosis and pyroptosis), and other related mechanisms. The current status of drug therapy for early-stage DR is also discussed to provide insights for the development of pharmaceutical interventions targeting the early treatment of DR.

Sodium-glucose co-transporter 2 inhibitor add-on therapy for metformin delays diabetic retinopathy progression in diabetes patients: a population-based cohort study

To investigate how sodium-glucose co-transporter 2 inhibitors (SGLT2is) add-on therapy for metformin affects diabetic retinopathy (DR) progression in patients with type 2 diabetes mellitus (T2DM). This nationwide population-based study conducted from January 1, 2016, to December 31, 2018 involved 3,432,911 adults with T2DM in Taiwan. To adjust for potential confounders, data on sex, age, income, comorbidities, diabetes complication severity index score, staging of kidney disease, anti-diabetic medications, and index year were included. The outcome was DR progression, determined by procedure codes or the addition of ICD-9-CM or ICD-10-CM codes to the medical records of the patients during the study. Sensitivity analyses were performed to validate the findings. The adjusted hazard ratio (aHR) of DR progression was 0.89 for the SGLT2is add-on group, relative to the control group [95% confidence interval (CI) 0.81-0.99, P = 0.026]. The Kaplan-Meier curve of the cumulative incidence rate showed that the cumulative incidence of DR progression was considerably decreased in the SGLT2is cohort (log-rank P = 0.0261). The use of SGLT2is for less than 1 year and 1-2 years were associated with a significant increase in the risk of DR progression (aHR 1.56 and 1.88, respectively); however, the risk markedly reduced if the SGLT2is regimen was used for more than 2 years (aHR 0.41, 95% Cl 0.35-0.48; P < 0.001). The serial sensitivity analysis showed consistent findings. The aHR of DR progression was 0.82 for the SGLT2is cohort relative to the non-SGLT2is cohort based on the fundoscopy or indirect ophthalmoscopy findings within 1 year before the outcome date (95% Cl 0.71-0.95; P = 0.009). Co-administration of metformin and SGLT2is may reduce the risk of DR progression. Short-term use of SGLT2is may markedly increase the risk of DR, whereas prolonged use SGLT2is may significantly decrease it.

Advances in the management of type 2 diabetes in adults

Type 2 diabetes is a chronic and progressive cardiometabolic disorder that affects more than 10% of adults worldwide and is a major cause of morbidity, mortality, disability, and high costs. Over the past decade, the pattern of management of diabetes has shifted from a predominantly glucose centric approach, focused on lowering levels of haemoglobin A1c (HbA1c), to a directed complications centric approach, aimed at preventing short term and long term complications of diabetes, and a pathogenesis centric approach, which looks at the underlying metabolic dysfunction of excess adiposity that both causes and complicates the management of diabetes. In this review, we discuss the latest advances in patient centred care for type 2 diabetes, focusing on drug and non-drug approaches to reducing the risks of complications of diabetes in adults. We also discuss the effects of social determinants of health on the management of diabetes, particularly as they affect the treatment of hyperglycaemia in type 2 diabetes.

The protective role of GLP-1 in neuro-ophthalmology

Despite recent advancements in the field of neuro-ophthalmology, the rising rates of neurological and ophthalmological conditions, mismatches between supply and demand of clinicians, and an aging population underscore the urgent need to explore new therapeutic approaches within the field. Glucagon-like peptide 1 receptor agonists (GLP-1RAs), traditionally used in the treatment of type 2 diabetes, are becoming increasingly appreciated for their diverse applications. Recently, GLP-1RAs have been approved for the treatment of obesity and recognized for their cardioprotective effects. Emerging evidence indicates some GLP-1RAs can cross the blood-brain barrier and may have neuroprotective effects. Therefore, this article aims to review the literature on the neurologic and neuro-ophthalmic role of glucagon-like peptide 1 (GLP-1). This article describes GLP-1 peptide characteristics and the mechanisms mediating its known role in increasing insulin, decreasing glucagon, delaying gastric emptying, and promoting satiety. This article identifies the sources and targets of GLP-1 in the brain and review the mechanisms which mediate its neuroprotective effects, as well as implications for Alzheimer's disease (AD) and Parkinson's disease (PD). Furthermore, the preclinical works which unravel the effects of GLP-1 in ocular dynamics and the preclinical literature regarding GLP-1RA use in the management of several neuro-ophthalmic conditions, including diabetic retinopathy (DR), glaucoma, and idiopathic intracranial hypertension (IIH) are discussed.

Dynamic nomogram prediction model for diabetic retinopathy in patients with type 2 diabetes mellitus

BACKGROUND

To develop a dynamic prediction model for diabetic retinopathy (DR) using systemic risk factors.

METHODS

This retrospective study included type 2 diabetes mellitus (T2DM) patients discharged from the Second Affiliated Hospital of Kunming Medical University between May 2020 and February 2022. The early patients (80%) were used for the training set and the late ones (20%) for the validation set.

RESULTS

Finally, 1257 patients (1049 [80%] in the training set and 208 [20%] in the validation set) were included; 360 (28.6%) of them had DR. The areas under the curves (AUCs) for the multivariate regression (MR), least absolute shrinkage and selection operator regression (LASSO), and backward elimination stepwise regression (BESR) models were 0.719, 0.727, and 0.728, respectively. The Delong test showed that the BESR model had a better predictive value than the MR (p = 0.04899) and LASSO (P = 0.04999) models. The DR nomogram risk model was established according to the BESR model, and it included disease duration, age at onset, treatment method, total cholesterol, urinary albumin to creatinine ratio (UACR), and urine sugar. The AUC, kappa coefficient, sensitivity, specificity, and compliance of the nomogram risk model in the validation set were 0.79, 0.48, 71.2%, 78.9%, and 76.4%, respectively.

CONCLUSIONS

A relatively reliable DR nomogram risk model was established based on the BESR model.

Network pharmacology mechanism of Scutellarin to inhibit RGC pyroptosis in diabetic retinopathy

To investigate the effect of scutellarin (SCU) in diabetic retinopathy (DR) and explore the associated molecular network mechanism. The animal model of DR was established from diabetic mellitus (DM) rats by intraperitoneally injected streptozotocin (STZ) at dosage 55 mg/kg. Meanwhile, SCU was intraperitoneally administrated to protect retina from cell pyroptosis induced by DM, and cell pyroptosis was detected by using HE, Nissl staining, and immunofluorescence recognition. Moreover, the hub gene involving in pyroptosis in DR was screened by bioinformatics and network pharmacology, designated as Venny intersection screen, GO and KEGG analysis, PPI protein interaction, and molecular docking. Lastly, the expressional change of hub genes were validated with experimental detection. Cell pyroptosis of the DR, specifically in retina ganglion cells (RGC), was induced in DM rats; SCU administration results in significant inhibition in the cell pyroptosis in DR. Mechanically, 4084 genes related to DR were screened from GeneCards and OMIM databases, and 120 SCU therapeutic targets were obtained, by using GeneCards, TCMSP with Swiss Target Prediction databases. Moreover, 357 targets related to pyroptosis were found using GenenCards database, and Drug, disease and phenotypic targets were analyzed online using the Draw Venn Diagram website, and 12 cross targets were obtained. Through GO function and KEGG pathway enrichment analysis, 659 BP related items, 7 CC related items, 30 MF related items, and 70 signal pathways were screened out; Of these, eleven proteins screened from cross-target PPI network were subsequently docked with the SCU, and their expressions including caspase-1, IL-1β, IL-18, GSDMD and NLRP3 in RGC indicated by immunofluorescence, and the mRNA expression for caspase-1 in DR indicated by quantitative PCR, were successfully validated. SCU can effectively protect RGC pyroptosis in DR, and underlying mechanisms are involved in the inhibition of caspase-1, GSDMD, NLRP3, IL-1β and IL-18. Our findings therefore provide crucial evidence to support the clinic practice of SCU for the treatment of DR, and explained the underlying molecular network mechanism.

Semaglutide-eye-catching results

Semaglutide is a glucagon-like peptide-1 receptor agonist used either orally every day or subcutaneously once a week for the treatment of type 2 diabetes mellitus and, more recently, at higher doses, for the treatment of obesity. Both diseases are reaching epidemic proportions and often coexist, posing patients with a high risk for cardiovascular disease and death. Therefore, an agent such as semaglutide, which offers clinically significant weight loss and cardiovascular benefits, is essential and will be increasingly used in high-risk patients. However, during the SUSTAIN clinical trial program (Semaglutide Unabated Sustainability in treat-ment of type 2 diabetes), a safety issue concerning the progression and worsening of diabetic retinopathy emerged. The existing explanation so far mainly supports the role of the magnitude and speed of HbA1c reduction, a phenomenon also associated with insulin treatment and bariatric surgery. Whether and to which extent the effect is direct is still a matter of debate and an intriguing topic to investigate for suitable preventative and rehabilitative purposes. In this minireview, we will summarize the available data and suggest guidelines for a comprehensive semaglutide clinical utilization until new evidence becomes available.

Anti-inflammatory effect of glucagon-like Peptide-1 receptor agonist on the neurosensory retina in an acute optic nerve injury rat model

PURPOSE

To explore the possibility of using glucagon-like peptide-1 receptor agonist (GLP-1RA) as a new treatment for neuroinflammation, by analyzing retinal pathological changes in an optic nerve crush rat model.

METHODS

Eight-week-old male Sprague-Dawley rats were divided into lixisenatide (LIX, n = 10), traumatic control (T-CON, n = 10), and normal control (n = 5) groups. The optic nerves of left eyes in the LIX and T-CON groups were crushed in a standardized manner. The LIX group was treated with subcutaneous injections of lixisenatide (200 μg/kg/day) for 5 days. One week after initiating treatment, quantitative polymerase chain reaction, Western blot, and immunohistochemistry analyses were performed on the retinal tissues of each group to identify inflammatory markers.

RESULTS

The LIX group showed significantly lower mRNA levels of interleukin 1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), thioredoxin interacting protein (TXNIP), and glial fibrillary acidic protein (GFAP) than the T-CON group. Also, the LIX group exhibited decreased TXNIP and GFAP expression compared with the T-CON group, and similar expression to the normal control group, according to Western blot analysis. Significantly increased immunohistochemistry staining of Brn3a and decreased TUNEL staining were seen in the LIX group compared with the T-CON group, indicating that lixisenatide contributes to retinal ganglion cell survival in cases of acute optic nerve injury.

CONCLUSIONS

Neuroinflammation was significantly reduced in lixisenatide-treated retinas compared with untreated retinas in our acute optic nerve injury rat model. The neuroprotective effect of lixisenatide indicates that it can serve a new treatment option against clinically intractable traumatic optic neuropathy.

Nomogram-based prediction of clinically significant macular edema in diabetes mellitus patients

AIMS

The aim of the study was to construct and validate a risk nomogram for clinically significant macular edema (CSME) prediction in diabetes mellitus (DM) patients using systemic variables.

METHODS

In this retrospective study, DM inpatients who underwent routine diabetic retinopathy screening were recruited and divided into training and validation sets according to their admission date. Ninety-three demographic and systemic variables were collected. The least absolute shrinkage and selection operator was used to select the predictive variables from the training set. The selected variables were used to construct the CSME prediction nomogram. Internal and external validations were performed. The C-index, calibration curve and decision curve analysis (DCA) were reported.

RESULTS

A total of 349 patients were divided into the training set (240, 68.77%) and the validation set (109, 31.23%). The presence of diabetic peripheral neuropathy (DPN) symptoms, uric acid, use of insulin only or not for treatment, insulin dosage, urinary protein grade and disease duration were chosen for the nomogram. The C-index of the prediction nomogram was 0.896, 0.878 and 0.837 in the training set, internal validation and external validation, respectively. The calibration curves of the nomogram showed good agreement between the predicted and actual outcomes. DCA demonstrated that the nomogram was clinically useful.

CONCLUSIONS

A nomogram with good performance for predicting CSME using systemic variables was developed. It suggested that DPN symptoms and renal function may be crucial risk factors for CSME. Moreover, this nomogram may be a convenient tool for non-ophthalmic specialists to rapidly recognize CSME in patients and to transfer them to ophthalmologists for early diagnosis and treatment.

Progression of retinopathy with glucagon-like peptide-1 receptor agonists with cardiovascular benefits in type 2 diabetes - A systematic review and meta-analysis

AIMS

The effect of Glucagon-like peptide 1 receptor agonists (GLP1 RA) on diabetic retinopathy (DR) remains controversial. Previous reviews combined data from randomized clinical trials (RCTs) with or without cardiovascular (CV) benefits and did not address confounders, therefore may have generated misleading results. The study aimed to examine the effect of GLP1RA on DR in type 2 diabetes (T2DM) in RCTs with or without CV benefits and distinguish the effect by major confounders.

METHODS

We conducted electronic searches of multiple databases and a manual search using references lists. We included 13 RCTs examining the effect of GLP1 RA on health outcomes/adverse events including DR or DR complications in T2DM. We performed a random-effects model meta-analysis.

RESULTS

GLP1RA was associated with an elevated risk of rapidly worsening DR in four major RCTs with CV benefits in T2DM (OR 1.23, 95 % CI 1.05-1.44). The association between GLP1 RA and DR was significant in subgroups of RCTs with length over 52 weeks (1.2, 1.00-1.43), using placebo as a comparator (1.22, 1.05-1.42). In subgroups with patients who had T2DM ≥10 years (1.19, 0.99-1.42) or with subjects enrolled from multiple countries (1.2, 0.99-1.46), the association appeared to be evident but did not reach statistical significance.

CONCLUSIONS

GLP1 RA including liraglutide, semaglutide, and dulaglutide are associated with an increased risk of rapidly worsening DR in RCTs with CV benefits. Further data from clinical studies with longer follow-up purposefully designed for DR risk assessment, particularly including patients of established DR are warranted.

Using Convolutional Neural Network as a Statistical Algorithm to Explore the Therapeutic Effect of Insulin Liposomes on Corneal Inflammation

Aiming at the disadvantages of easy recurrence of keratitis, difficult eradication by surgery, and easy bacterial resistance, insulin-loaded liposomes were prepared, and convolutional neural network was used as a statistical algorithm to build SD rat corneal inflammation model and study insulin-loaded liposomes, alleviating effect on corneal inflammatory structure in SD rats. The INS/PFOB@LIP was developed by means of thin-film dispersive phacoemulsification, its structure was monitored using a transmission electron microscope, particle size and appearance potential were monitored using a Malvern particle sizer, and ultraviolet consumption spectrum was monitored using a UV spectrophotometer. The encapsulation rate, drug loading, and distribution of insulin liposomes in rat corneal inflammatory model were measured and calculated. The cytotoxicity of liposome materials was evaluated by CCK-8 assay, and the toxic effects of insulin and insulin liposomes on cells were detected. The cornea of SD rats was burned with NaOH solution (1 mol/L), and the SD rat corneal inflammation model was created. The insulin liposome was applied to the corneal inflammation model, and the therapeutic effect of insulin liposome on corneal inflammation was evaluated by slit lamp, corneal immunohistochemistry, corneal HE staining, and corneal Sirius red staining. Insulin-loaded liposomes were successfully constructed with an average particle size of (130.69 ± 3.87) nm and a surface potential of (−38.24 ± 2.57) mV. The encapsulation rate of insulin liposomes was (48.89 ± 1.24)%, and the drug loading rate was (24.45 ± 1.24)%. The SD rat corneal inflammation model was successfully established. After insulin liposome treatment, the staining area of corneal fluorescein sodium was significantly reduced, the corneal epithelium was significantly thickened, the content of corneal collagen was increased, the expression of inflammatory factors was significantly reduced, and new blood vessels (corneal neovascularization, CNV) growth was inhibited.

Maslinic Acid Protects against Streptozotocin-Induced Diabetic Retinopathy by Activating Nrf2 and Suppressing NF-κB

This study tested the protective effect of maslinic acid (MA) against diabetic retinopathy (DR) in rats with type 1 diabetes mellitus (T1DM) and investigated possible mechanisms of action. DM was introduced by streptozotocin (STZ) (65 mg/kg, i.p.). Control and STZ (T1DM) were divided into 2 subgroups, which received either the vehicle or MA (80 mg/kg). Serum, pancreases, and retinas were collected for further use. MA significantly reduced fasting glucose levels in the control and T1DM rats but enhanced fasting insulin levels and partially increased the size of the islets of Langerhans and the number of β-cells in T1DM rats. In addition, MA significantly improved the retina structure by preventing the reduction in the area between the inner and outer limiting membranes (ILM and OLM, respectively) and increasing the number of cells forming the ganglion cell layer (GCL), inner nuclear layer (INL), and outer nuclear layer (ONL). Associated with these effects, MA significantly reduced the total levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), as well as the nuclear levels of NF-κB p65, mRNA levels of Bax, and protein levels of cleaved caspase-3 in the retinas of T1DM rats. However, MA significantly lowered levels of reactive oxygen species (ROS) and malondialdehyde (MDA) but significantly increased the nuclear levels of Nrf2, protein levels of Bcl2, and total levels of superoxide dismutase (SOD) and reduced glutathione (GSH) in the retinas of the control and T1DM rats. In conclusion, MA prevents DR by antioxidant potential mediated by the activation of Nrf2.

Glucagon-Like Peptide 1 Receptor Agonists – Potential Game Changers in the Treatment of Glaucoma?

Glaucoma is a common ocular neurodegenerative disease characterized by the progressive loss of retinal ganglion cells and their axons. It is the most common cause of irreversible blindness. With an increasing number of glaucoma patients and disease progression despite treatment, it is paramount to develop new and effective therapeutics. Emerging new candidates are the receptor agonists of the incretin hormone glucagon-like-peptide-1 (GLP-1), originally used for the treatment of diabetes. GLP-1 receptor (GLP-1R) agonists have shown neuroprotective effects in preclinical and clinical studies on neurodegenerative diseases in both the brain (e.g., Alzheimer’s disease, Parkinson’s disease, stroke and diabetic neuropathy) and the eye (e.g., diabetic retinopathy and AMD). However, there are currently very few studies investigating the protective effects of GLP-1R agonists in the treatment of specifically glaucoma. Based on a literature search on PubMed, the Cochrane Library, and ClinicalTrials.gov, this review aims to summarize current clinical literature on GLP-1 receptor agonists in the treatment of neurodegenerative diseases to elucidate their potential in future anti-glaucomatous treatment strategies.

The Impact of Hypoglycemia on Patients with Diabetes Mellitus: A Cross-Sectional Analysis

The increasing mortality and morbidity in patients with diabetes mellitus constitute a severe public health problem. The condition is recognized as a cause of impaired quality of life, high costs, and diminished productivity. In this study, we performed a cross-sectional analysis among 300 Polish participants with type 1 and type 2 diabetes to determine and classify risk factors associated with increased incidences of hypoglycemia. Including an open-access knowledge about the correlations between diabetes rates and human’s lifestyle, we confirm that the frequency of smoking and drinking alcohol, low BMI, inappropriate diet, low physical activity, lack of vaccination against influenza and pneumococci, and co-existence of other comorbidities such as cardiovascular diseases, thyroid diseases, hyperlipidemia, retinopathy, and asthma elevate the risk of hypoglycemia. Furthermore, hypoglycemic patients were more often malnourished, depressed, irritated, and exposed to stress. In sum, the analysis of the interaction between diabetes and sociodemographic, environmental, or other disease-related risk factors provides strategies to optimize glycemic control and reduce the incidence of hypoglycemia. Furthermore, we believe our findings may constitute a basis for promoting health by adjusting available and implementing new preventive services reducing hypoglycemic episodes in diabetic patients.

Outcomes of Diabetic Retinopathy Post-Bariatric Surgery in Patients with Type 2 Diabetes Mellitus

Bariatric surgery is an emerging therapeutic approach for obese type 2 diabetes mellitus (T2DM) patients, with proven benefits for achieving target glucose control and even remission of diabetes. However, the effect of bariatric surgery upon diabetic retinopathy is still a subject of debate as some studies show a positive effect while others raise concerns about potential early worsening effects. We performed a systematic review, on PubMed, Science Direct, and Web of Science databases regarding the onset and progression of diabetic retinopathy in obese T2DM patients who underwent weight-loss surgical procedures. A total of 6375 T2DM patients were analyzed. Most cases remained stable after bariatric surgery (89.6%). New onset of diabetic retinopathy (DR) was documented in 290 out of 5972 patients (4.8%). In cases with DR at baseline, progression was documented in 50 out of 403 (12.4%) and regression in 90 (22.3%). Preoperative careful preparation of hemoglobin A1c (HbA1c), blood pressure, and lipidemia should be provided to minimize the expectation of DR worsening. Ophthalmologic follow-up should be continued regularly in the postoperative period even in the case of diabetic remission. Further randomized trials are needed to better understand the organ-specific risk factors for progression and provide personalized counseling for T2DM patients planned for bariatric surgery.

Profiles of Intraday Glucose in Type 2 Diabetes and Their Association with Complications: An Analysis of Continuous Glucose Monitoring Data

Aims: To identify profiles of type 2 diabetes from continuous glucose monitoring (CGM) data using ambulatory glucose profile (AGP) indicators and examine the association with prevalent complications. Methods: Two weeks of CGM data, collected between 2015 and 2019, from 5901 adult type 2 diabetes patients were retrieved from a clinical database in Chennai, India. Non-negative matrix factorization was used to identify profiles as per AGP indicators. The association of profiles with existing complications was examined using multinomial and logistic regressions adjusted for glycated hemoglobin (HbA1c; %), sex, age at onset, and duration of diabetes. Results: Three profiles of glycemic variability (GV) were identified based on CGM data-Profile 1 ["TIR Profile"] (n = 2271), Profile 2 ["Hypo"] (n = 1471), and Profile 3 ["Hyper"] (n = 2159). Compared with time in range (TIR) profile, those belonging to Hyper had higher mean fasting plasma glucose (202.9 vs. 167.1, mg/dL), 2-h postprandial plasma glucose (302.1 vs. 255.6, mg/dL), and HbA1c (9.7 vs. 8.6; %). Both "Hypo profile" and "Hyper profile" had higher odds of nonproliferative diabetic retinopathy ("Hypo": 1.44, 1.20-1.73; "Hyper": 1.33, 1.11-1.58), macroalbuminuria ("Hypo": 1.58, 1.25-1.98; "Hyper": 1.37, 1.10-1.71), and diabetic kidney disease (DKD; "Hypo": 1.65, 1.18-2.31; "Hyper": 1.88, 1.37-2.58), compared with "TIR profile." Those in "Hypo profile" (vs. "TIR profile") had higher odds of proliferative diabetic retinopathy (PDR; 2.84, 1.65-2.88). Conclusions: We have identified three profiles of GV from CGM data. While both "Hypo profile" and "Hyper profile" had higher odds of prevalent DKD compared with "TIR profile," "Hypo profile" had higher odds of PDR. Our study emphasizes the clinical importance of recognizing and treating hypoglycemia (which is often unrecognized without CGM) in patients with type 2 Diabetes Mellitus.

Management of Patients with Newly Diagnosed Diabetic Mellitus: Ophthalmologic Outcomes in Intensive versus Conventional Glycemic Control

Background and Objective

Diabetic retinopathy, a microvascular complication of diabetes mellitus, is one of the most important causes of visual loss in developed countries. Our objective is to evaluate the efficacy of intensive versus conventional glycemic control of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) patients in terms of ophthalmologic outcome, pathogenesis of the early worsening of diabetic retinopathy, risk factors for early worsening and diabetic retinopathy progression.

Methods

A literature search on publications concerning glycaemic control in diabetic retinopathy and management of newly diagnosed diabetes mellitus by intensive versus conventional glycaemic control.

Results

A total of 22 articles were reviewed after curation by the authors for relevance. Nineteen articles are randomized control trial, 2 articles are observational studies and 1 is clinical trial. Fifteen articles investigated the glycaemic control in T1DM-related diabetic retinopathy and 8 on T2DM-related diabetic retinopathy. The level of glycemia (in terms of HbA1c level) is significantly related to the diabetic retinopathy progression in both T1DM and T2DM. Intensive glycemic control was found to reduce the development of severe diabetic retinopathy, including severe non-proliferative diabetic retinopathy, neovascularization, clinically significant macular edema and loss of vision. Early worsening of diabetic retinopathy commonly occurs during the first year of intensive treatment, especially those initially present with proliferative or severe non-proliferative retinopathy. However, most patients with early worsening can recover and their long-term ophthalmologic outcomes are better when compared to conventional glycemic control.

Conclusion

The current guideline on HbA1c level is considered sufficient for the minimization of diabetic retinopathy progression. More frequent monitoring for early worsening should be recommended for newly diagnosed diabetes cases already presenting with retinopathy.

Exosomal Vimentin from Adipocyte Progenitors Protects Fibroblasts against Osmotic Stress and Inhibits Apoptosis to Enhance Wound Healing

Mechanical stress following injury regulates the quality and speed of wound healing. Improper mechanotransduction can lead to impaired wound healing and scar formation. Vimentin intermediate filaments control fibroblasts’ response to mechanical stress and lack of vimentin makes cells significantly vulnerable to environmental stress. We previously reported the involvement of exosomal vimentin in mediating wound healing. Here we performed in vitro and in vivo experiments to explore the effect of wide-type and vimentin knockout exosomes in accelerating wound healing under osmotic stress condition. Our results showed that osmotic stress increases the size and enhances the release of exosomes. Furthermore, our findings revealed that exosomal vimentin enhances wound healing by protecting fibroblasts against osmotic stress and inhibiting stress-induced apoptosis. These data suggest that exosomes could be considered either as a stress modifier to restore the osmotic balance or as a conveyer of stress to induce osmotic stress-driven conditions.

[Concentration of VEGF-A in the intraocular fluid of rats with alloxan model of diabetes mellitus]

PURPOSE

To study the changes in the concentration of vascular endothelial growth factor A (VEGF-A) in the intraocular fluid (IOF) of rats with alloxan model of diabetes mellitus (DM) on insulin therapy at different time points.

MATERIAL AND METHODS

The alloxan model of DM was simulated in 197 rats by a single intraperitoneal injection of 100 mg/kg alloxan hydrate. The animals were divided into 3 groups 7 days after administration of alloxan hydrate. The main group consisted of animals with alloxan model of DM, which begain receiving single daily intraperitoneal injections of insulin at a dose of 0.9 U/kg body weight. The comparison group included animals with alloxan model of DM, which did not receive the therapy. The control group consisted of healthy animals. The experimental animals were withdrawn from the study 1 and 4 months after the start of insulin therapy. The concentration of VEGF-A was determined in 80-90 μL of intraocular fluid collected from both eyes of each animal.

RESULTS

At 1 month, the VEGF-A concentration in the intraocular fluid in the study group (n=17; 140 [136; 210] pg/mL) was statistically significantly higher than in the comparison group (n=20; 72 [58; 86] pg/mL; p_m-u<0.0004), and in the control group (n=16; 76 [62.5; 88] pg/mL; p_m-u=0.0045). The comparison group did not have statistically significant differences from the control group (p_m-u=0.9979). At 4 months, the VEGF-A concentration in the intraocular fluid in the study group (n=18) was 84.8 [61.1; 93.2] pg/mL, in the comparison group (n=16) - 66.4 [54.4; 73.75] pg/mL. The VEGF-A concentration in the intraocular fluid in the study group at 4 months was statistically significantly lower than in the study group at 1 month (p_m-u<0.0044).

CONCLUSION

Insulin therapy causes a statistically significant increase in the concentration of VEGF-A in the intraocular fluid of rats with alloxan model of DM after 1 month, but after 4 months of the therapy the VEGF-A concentration falls back to the initial values.

The Safety of Pharmacological and Surgical Treatment of Diabetes in Patients with Diabetic Retinopathy-A Review

BACKGROUND

Diabetes mellitus (DM) is a non-infectious pandemic of the modern world; it is estimated that in 2045 it will affect 10% of the world's population. As the prevalence of diabetes increases, the problem of its complications, including diabetic retinopathy (DR), grows. DR is a highly specific neurovascular complication of diabetes that occurs in more than one third of DM patients and accounts for 80% of complete vision loss cases in the diabetic population. We are currently witnessing many groundbreaking studies on new pharmacological and surgical methods of treating diabetes.

AIM

The aim of the study is to assess the safety of pharmacological and surgical treatment of DM in patients with DR.

MATERIAL AND METHODS

An analysis of the data on diabetes treatment methods currently available in the world literature and their impact on the occurrence and progression of DR.

RESULTS

A rapid decrease in glycaemia leads to an increased occurrence and progression of DR. Its greatest risk accompanies insulin therapy and sulfonylurea therapy. The lowest risk of DR occurs with the use of SGLT2 inhibitors; the use of DPP-4 inhibitors and GLP-1 analogues is also safe. Patients undergoing pancreatic islet transplants or bariatric surgeries require intensive monitoring of the state of the eye, both in the perioperative and postoperative period.

CONCLUSIONS

It is of utmost importance to individualize therapy in diabetic patients, in order to gradually achieve treatment goals with the use of safe methods and minimize the risk of development and progression of DR.

National trends in the prevalence of diabetic retinopathy among Thai patients with type 2 diabetes and its associated factors from 2014 to 2018

Introduction

Diabetic retinopathy (DR) is one of the most common and serious ocular complications in both developed and developing countries. To date, epidemiological data of DR and their associated factors in Southeast Asian countries especially in Thailand are scarce. We aimed to use the information from the Thailand Diabetes Mellitus/Hypertension (DM/HT) study to determine trends in DR prevalence and also risk factors among Thai patients with type 2 diabetes (T2D).

Methods

A series of cross-sectional surveys of clinical outcomes was conducted annually in 2014, 2015 and 2018 among patients with T2D aged >18 years receiving medical care for at least 12 months. A stratified single stage cluster sampling method that was proportional to the size sampling technique was used to select a nationally and provincially representative sample of patients with T2D in Thailand. A standardized case report form was used to obtain the required information from medical records.

Results

A total of 104,472 Thai patients with T2D were included in the study from 2014 to 2018. The dominant proportion of participants, 70,756 (67.7%), were females. The overall prevalence of DR declined from 6.9% in 2014 to 6.3% in 2015 and 5.0% in 2018 (p for trend <0.001). The independent associated factors with DR included survey year, greater duration of DM, geographic region, hospital level, social security scheme, dyslipidemia, insulin therapy, high HbA1c level and elevated pulse pressure.

Conclusion

We reported a decreasing in trend in the prevalence of DR among Thai patients with T2D over one half decade. Patients with T2D should be encouraged to control their underlying diseases and engage in other effective interventions. When these modifiable risk factors can be inhibited, DR and other cardiovascular complications will be alleviated.

Characteristics Associated with Early Worsening of Retinopathy in Patients with Type 2 Diabetes Diagnosed with Retinopathy at Their First Visit: A Retrospective Observational Study

MATERIALS AND METHODS

Our study design was a retrospective observational study. Subjects with type 2 diabetes diagnosed with either simple or preproliferative diabetic retinopathy by ophthalmologists at their first visit and followed up for 6-18 months thereafter were included and divided into worsening and nonworsening groups. Thereafter, baseline characteristics and changes in HbA1c and therapy over a year were investigated.

RESULTS

Among the 88 subjects with simple diabetic retinopathy, 16% improved to no retinopathy, 65% retained their simple diabetic retinopathy, 18% worsened to preproliferative diabetic retinopathy, and 1% worsened to proliferative diabetic retinopathy. Among the 47 subjects with preproliferative diabetic retinopathy, 9% improved to simple diabetic retinopathy, 72% retained their preproliferative diabetic retinopathy, and 19% worsened to proliferative diabetic retinopathy. Patients with simple diabetic retinopathy had an odds ratio of 1.44 for worsening retinopathy with a 1% increase in baseline HbA1c. Meanwhile, the odds ratios for worsening retinopathy with a 1% decrease in HbA1c from baseline at 3, 6, and 12 months were 1.34, 1.31, and 1.38, respectively. Among patients with simple diabetic retinopathy, significantly more new interventions were introduced in the worsening group than in the nonworsening group.

CONCLUSIONS

Increased baseline HbA1c, a substantial decrease in HbA1c, and intensified therapy were identified as risk factors for early worsening of diabetic retinopathy in patients with simple diabetic retinopathy at the first visit. Patients should therefore be intimately followed for retinopathy after their first visit.

Effects of Diabetes on Microcirculation and Leukostasis in Retinal and Non-Ocular Tissues: Implications for Diabetic Retinopathy

Changes in retinal microcirculation are associated with the development of diabetic retinopathy (DR). However, it is unclear whether such changes also develop in capillary beds of other non-retinal tissues. Here, we investigated microcirculatory changes involving velocity of rolling neutrophils, adherence of neutrophils, and leukostasis during development of retinal vascular lesions in diabetes in other non-retinal tissues. Intravital microscopy was performed on post-capillary venules of cremaster muscle and ear lobe of mice with severe or moderate diabetes and compared to those of non-diabetic mice. Additionally, number and velocity of rolling leukocytes, number of adherent leukocytes, and areas of leukostasis were quantified, and retinal capillary networks were examined for acellular capillaries (AC) and pericyte loss (PL), two prominent vascular lesions characteristic of DR. The number of adherent neutrophils and areas of leukostasis in the cremaster and ear lobe post-capillary venules of diabetic mice was increased compared to those of non-diabetic mice. Similarly, a significant increase in the number of rolling neutrophils and decrease in their rolling velocities compared to those of non-diabetic control mice were observed and severity of diabetes exacerbated these changes. Understanding diabetes-induced microcirculatory changes in cremaster and ear lobe may provide insight into retinal vascular lesion development in DR.

Previous dramatic reduction of HbA1c and retinopathy in Type 2 Diabetes

AIMS

Does Diabetic Retinopathy (DR) relate to a previous dramatic reduction of HbA1c in Type 2 Diabetes (T2D)?

METHODS

In patients hospitalized for T2D, we collected HbA1c values from previous years, and we defined "Rapid declinors" by a more than -3% reduction between two consecutive HbA1c, and "sustained moderate declinors" by HbA1c declining less than -3%. We analyzed the relation between DR and previous HbA1c courses, adjusted for other risk factors.

RESULTS

Our 680 patients had a mean HbA1c at 8.7 ± 1.7% at admission and 8.7 ± 1.8 to 9.0 ± 2.2% during previous years (1500 HbA1C values collected), and 24% had a DR. A previous rapid decline of HbA1c occurred in 13.5% of subjects and related to DR (OR = 1.86, 95%CI:1.02-3.40), especially proliferative (OR = 2.64, 95%CI:1.02-6.80), after adjustment for age, gender, body mass index, arterial hypertension and diabetic kidney disease, blood lipids and statin treatment, duration of diabetes and mean previous HbA1c. A previous moderate reduction of HbA1c as occurred in 28.3% other subjects was not related to DR.

CONCLUSIONS

In subjects hospitalized for T2D, a previous rapid decline of HbA1c was related to proliferative DR, whereas a sustained moderate decline appeared to be safe.

Worsening of diabetic retinopathy with rapid improvement in systemic glucose control: A review

Worsening of diabetic retinopathy (DR) is associated with the initiation of effective treatment of glycaemia in some patients with diabetes. It has been associated with risk factors such as poor blood-glucose control and hypertension, and it manifests prior to the long-term benefits of optimizing glycaemic control. The majority of evidence supports an association of large and rapid reductions in blood-glucose levels with early worsening of DR. Despite a general awareness of early worsening within the diabetes community, mechanisms to explain the phenomenon remain speculative. We provide an overview of early worsening of DR and its pathophysiology based on current data. We describe the phenomenon in various settings, including in patients receiving insulin- or non-insulin-based treatments, in those undergoing bariatric surgery, and in pregnant women. We discuss various mechanisms and theories that have been suggested to explain this paradoxical phenomenon, and we summarize the implications of these in clinical practice.

Specialized Pro-resolving Lipid Mediators: Modulation of Diabetes-Associated Cardio-, Reno-, and Retino-Vascular Complications

Diabetes and its associated chronic complications present a healthcare challenge on a global scale. Despite improvements in the management of chronic complications of the micro-/macro-vasculature, their growing prevalence and incidence highlights the scale of the problem. It is currently estimated that diabetes affects 425 million people globally and it is anticipated that this figure will rise by 2025 to 700 million people. The vascular complications of diabetes including diabetes-associated atherosclerosis and kidney disease present a particular challenge. Diabetes is the leading cause of end stage renal disease, reflecting fibrosis leading to organ failure. Moreover, diabetes associated states of inflammation, neo-vascularization, apoptosis and hypercoagulability contribute to also exacerbate atherosclerosis, from the metabolic syndrome to advanced disease, plaque rupture and coronary thrombosis. Current therapeutic interventions focus on regulating blood glucose, glomerular and peripheral hypertension and can at best slow the progression of diabetes complications. Recently advanced knowledge of the pathogenesis underlying diabetes and associated complications revealed common mechanisms, including the inflammatory response, insulin resistance and hyperglycemia. The major role that inflammation plays in many chronic diseases has led to the development of new strategies aiming to promote the restoration of homeostasis through the "resolution of inflammation." These strategies aim to mimic the spontaneous activities of the 'specialized pro-resolving mediators' (SPMs), including endogenous molecules and their synthetic mimetics. This review aims to discuss the effect of SPMs [with particular attention to lipoxins (LXs) and resolvins (Rvs)] on inflammatory responses in a series of experimental models, as well as evidence from human studies, in the context of cardio- and reno-vascular diabetic complications, with a brief mention to diabetic retinopathy (DR). These data collectively support the hypothesis that endogenously generated SPMs or synthetic mimetics of their activities may represent lead molecules in a new discipline, namely the 'resolution pharmacology,' offering hope for new therapeutic strategies to prevent and treat, specifically, diabetes-associated atherosclerosis, nephropathy and retinopathy.

Development of diabetic retinopathy after cataract surgery

This study explored whether cataract surgery precipitates diabetic retinopathy (DR) development in diabetic patients without previous DR. Patients with the diagnosis of type II diabetes but without DR were selected from the Longitudinal Health Insurance Database 2000. Patients who received cataract surgery between January 1, 2000, and December 31, 2010, were included in the case group, and the control group was matched to the case group by age, sex, and index year. The postoperative incidence rates of nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), and diabetic macular edema (DME) were the main outcomes studied and were adjusted by age, sex, comorbidities, and statin, fibrate, angiotensin-converting-enzyme inhibitor (ACEI), oral hypoglycemic agents (OHA), and insulin use. In our cohort, patients who had dyslipidemia and used statins were more likely to undergo cataract surgery. Among diabetic patients without previous DR, patients receiving cataract surgery had a higher risk of NDPR development (adjusted hazard ratio = 1.48, 95% confidence interval = 1.15–1.91). No statistical difference was observed in PDR or DME development between operative and nonoperative groups. In additional stratified analyses, female sex, older age, comorbidities, surgery within 5 years, statin, ACEI, OHA, and insulin use increased the risk of NPDR development. In an adjusted Cox regression model, cataract surgery, OHA and insulin use were found to be risk factors for NPDR development. Cataract surgery with complications increased post-operative risks for NPDR were even higher, and the significant influence from cataract surgery persisted 5 years after surgery.