Diabetic Retinopathy and Diabetic Macular Edema

Multi-Omics Analysis Revealed the rSNPs Potentially Involved in T2DM Pathogenic Mechanism and Metformin Response

The goal of our study was to identify and assess the functionally significant SNPs with potentially important roles in the development of type 2 diabetes mellitus (T2DM) and/or their effect on individual response to antihyperglycemic medication with metformin. We applied a bioinformatics approach to identify the regulatory SNPs (rSNPs) associated with allele-asymmetric binding and expression events in our paired ChIP-seq and RNA-seq data for peripheral blood mononuclear cells (PBMCs) of nine healthy individuals. The rSNP outcomes were analyzed using public data from the GWAS (Genome-Wide Association Studies) and Genotype-Tissue Expression (GTEx). The differentially expressed genes (DEGs) between healthy and T2DM individuals (GSE221521), including metformin responders and non-responders (GSE153315), were searched for in GEO RNA-seq data. The DEGs harboring rSNPs were analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). We identified 14,796 rSNPs in the promoters of 5132 genes of human PBMCs. We found 4280 rSNPs to associate with both phenotypic traits (GWAS) and expression quantitative trait loci (eQTLs) from GTEx. Between T2DM patients and controls, 3810 rSNPs were detected in the promoters of 1284 DEGs. Based on the protein-protein interaction (PPI) network, we identified 31 upregulated hub genes, including the genes involved in inflammation, obesity, and insulin resistance. The top-ranked 10 enriched KEGG pathways for these hubs included insulin, AMPK, and FoxO signaling pathways. Between metformin responders and non-responders, 367 rSNPs were found in the promoters of 131 DEGs. Genes encoding transcription factors and transcription regulators were the most widely represented group and many were shown to be involved in the T2DM pathogenesis. We have formed a list of human rSNPs that add functional interpretation to the T2DM-association signals identified in GWAS. The results suggest candidate causal regulatory variants for T2DM, with strong enrichment in the pathways related to glucose metabolism, inflammation, and the effects of metformin.

Metabolomics combined with intestinal microbiota reveals the mechanism of compound Qilian tablets against diabetic retinopathy

Background

Diabetic retinopathy (DR) is one of the common chronic complications of diabetes mellitus, which has developed into the leading cause of irreversible visual impairment in adults worldwide. Compound Qilian tablets (CQLT) is a traditional Chinese medicine (TCM) developed for treating DR, but its mechanism is still unclear. This study explored the mechanism of action of CQLT in treating DR through metabolomics and intestinal microbiota.

Methods

Histopathologic examination of the pancreas and retina of Zucker diabetic fatty (ZDF) rats and immunohistochemistry were used to determine the expression levels of retinal nerve damage indicators ionized calcium binding adaptor molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP). Rat fecal samples were tested by LC-MS metabolomics to search for potential biomarkers and metabolic pathways for CQLT treatment of DR. Characteristic nucleic acid sequences of rat intestinal microbiota from each group were revealed using 16S rDNA technology to explore key microbes and related pathways for CQLT treatment of DR. At the same time, we investigated the effect of CQLT on the gluconeogenic pathway.

Results

After CQLT intervention, islet cell status was improved, Iba-1 and GFAP expression were significantly decreased, and abnormal retinal microvascular proliferation and exudation were ameliorated. Metabolomics results showed that CQLT reversed 20 differential metabolites that were abnormally altered in DR rats. Intestinal microbiota analysis showed that treatment with CQLT improved the abundance and diversity of intestinal flora. Functional annotation of metabolites and intestinal flora revealed that glycolysis/gluconeogenesis, alanine, aspartate and glutamate metabolism, starch and sucrose metabolism were the main pathways for CQLT in treating DR. According to the results of correlation analysis, there were significant correlations between Iba-1, GFAP, and intestinal microbiota and metabolites affected by CQLT. In addition, we found that CQLT effectively inhibited the gluconeogenesis process in diabetic mice.

Conclusion

In conclusion, CQLT could potentially reshape intestinal microbiota composition and regulate metabolite profiles to protect retinal morphology and function, thereby ameliorating the progression of DR.

Photobiomodulation use in ophthalmology - an overview of translational research from bench to bedside

Photobiomodulation (PBM) refers to the process in which wavelengths of light are absorbed by intracellular photoacceptors, resulting in the activation of signaling pathways that culminate in biological changes within the cell. PBM is the result of low-intensity light-induced reactions in the cell in contrast to thermal photoablation produced by high-intensity lasers. PBM has been effectively used in the clinic to enhance wound healing and mitigate pain and inflammation in musculoskeletal conditions, sports injury, and dental applications for many decades. In the past 20 years, experimental evidence has shown the benefit of PBM in increasing numbers of retinal and ophthalmic conditions. More recently, preclinical findings in ocular models have been translated to the clinic with promising results. This review discusses the preclinical and clinical evidence of the effects of PBM in ophthalmology and provides recommendations of the clinical use of PBM in the management of ocular conditions.

FTY720 Suppresses Pathogenic Retinal Müller Cell Activation and Chronic Progression by Inhibiting the mTOR/NF-κB Signaling Pathway and Regulating Autophagy

PURPOSE

FTY720 is an agonist of the Sphingosine-1-phosphate (S1P) receptor 1, 3, 4, and 5 and a functional antagonist of the S1P1 receptor; it can inhibit the activation of mTOR/NF-κB and has therapeutic potential in inflammatory disease. This study was designed to determine the role of the inflammatory process in diabetic retinopathy and investigate the effect of FTY720 on high glucose (HG)-induced rat retinal Müller cells (rMC-1 cells).

METHODS

In the present study, the role of FTY720 in inhibiting inflammation and its underlying mechanism were investigated. rMC-1 cells were treated without or with HG, FTY720, CQ, or RAP. Cell viability was examined by CCK-8 assay; cell activation was assessed by western blot analysis and IF staining; and cell migration was evaluated by a scratch wound healing assay. The expression of inflammation-associated proteins and autophagy-related proteins was evaluated by transmission electron microscopy, AO staining, MDC-labeled autophagic vacuoles, western blot analysis and ELISA.

RESULTS

Western blot analysis and IF staining showed that the level of the rMC-1 cell marker GFAP was decreased, while GS was increased in FTY720 groups compared to that in the HG group. The healing assay results showed that compared with HG treatment, FTY720 treatment significantly reduced cell migration. Western blot analysis, ELISA and IF staining showed that compared with HG, FTY720 reduced proinflammatory proteins by inhibiting the mechanistic target of the mTOR/NF-κB signaling pathway and regulating autophagy.

CONCLUSIONS

This study suggests that in an HG-induced rMC-1 cell model, FTY720 significantly inhibited the production of inflammatory cytokines by inhibiting mTOR/NF-κB signaling and regulating autophagy. These findings were associated with a decrease in rMC-1 cell injury, suggesting that FTY720 or related compounds may be valuable modulators of HG-induced retinal injury.

Semantic uncertainty Guided Cross-Transformer for enhanced macular edema segmentation in OCT images

Macular edema, a prevalent ocular complication observed in various retinal diseases, can lead to significant vision loss or blindness, necessitating accurate and timely diagnosis. Despite the potential of deep learning for segmentation of macular edema, challenges persist in accurately identifying lesion boundaries, especially in low-contrast and noisy regions, and in distinguishing between Inner Retinal Fluid (IRF), Sub-Retinal Fluid (SRF), and Pigment Epithelial Detachment (PED) lesions. To address these challenges, we present a novel approach, termed Semantic Uncertainty Guided Cross-Transformer Network (SuGCTNet), for the simultaneous segmentation of multi-class macular edema. Our proposed method comprises two key components, the semantic uncertainty guided attention module (SuGAM) and the Cross-Transformer module (CTM). The SuGAM module utilizes semantic uncertainty to allocate additional attention to regions with semantic ambiguity, improves the segmentation performance of these challenging areas. On the other hand, the CTM module capitalizes on both uncertainty information and multi-scale image features to enhance the overall continuity of the segmentation process, effectively minimizing feature confusion among different lesion types. Rigorous evaluation on public datasets and various OCT imaging device data demonstrates the superior performance of our proposed method compared to state-of-the-art approaches, highlighting its potential as a valuable tool for improving the accuracy and reproducibility of macular edema segmentation in clinical settings, and ultimately aiding in the early detection and diagnosis of macular edema-related diseases and associated retinal conditions.

Comparison of ranibizumab, aflibercept, and dexamethasone implant monotherapy in treatment-naive eyes with diabetic macular edema: A 12-month real-life experience

PURPOSE

To compare the functional and anatomical outcomes of ranibizumab, aflibercept, and dexamethasone implant monotherapy in treatment-naive eyes with diabetic macular edema (DME) in real-life conditions.

METHODS

In this retrospective cohort study, data were obtained from the hospital database of treatment-naive patients diagnosed with DME with at least 12 months of follow-up. Best corrected visual acuity (BCVA) and central retinal thickness (CRT) at baseline, third month, sixth month, ninth month, and 12th month were recorded. In addition, a subgroup analysis was performed based on having good (below 0.4 log of minimum angle of resolution [logMAR]) or poor (0.4 logMAR and above) vision.

RESULTS

A total of 219 eyes of 142 patients were included in the study. The change in the mean BCVA from baseline to 12th month was from 0.62 logMAR to 0.42 logMAR (P < 0.001) in the ranibizumab group, from 0.56 logMAR to 0.39 logMAR (P < 0.001) in the aflibercept group, and from 0.46 logMAR to 0.5 logMAR (P = 0.653) in the dexamethasone group. There was no significant difference between the treatment groups at any time point (P > 0.05). The mean amount of CRT change was statistically significant at 12 months in all groups (ranibizumab: -175.4 µm, aflibercept: -153.3 µm, dexamethasone: -71.4 µm) (P < 0.05). In eyes with initially good vision, the final BCVA at 12 months was significantly better in the ranibizumab group compared to the dexamethasone group (P = 0.008). The aflibercept group had better visual acuity than the dexamethasone group, but there was no statistically significant difference (P = 0.059). There was no significant difference in final BCVA in eyes with initially poor vision. No serious ocular/systemic complications were noted.

CONCLUSION

At the 12th month, a significant decrease in CRT was achieved in all treatment groups, whereas only ranibizumab and aflibercept groups had a significant BCVA increase. In eyes with initially good vision, the final BCVA at 12 months was better in the ranibizumab group compared to the dexamethasone group, whereas it was similar in all groups having initially poor vision.

Diabetic Macular Edema Is Predictive of Renal Failure in Patients With Diabetes Mellitus and Chronic Kidney Disease

CONTEXT

Chronic hyperglycemia in patients with diabetes mellitus (DM) causes retinal damage and leakage, resulting in vision loss. Although diabetic retinopathy (DR) and diabetic kidney disease (DKD) are usually correlated, the relationship between diabetic macular edema (DME) and DKD remains unknown.

OBJECTIVE

To assess whether DME presence can predict renal failure in patients with DM and chronic kidney disease (CKD).

METHODS

This retrospective cohort study used data from 120 healthcare organizations in the TriNetX network. Electronic medical records of approximately 90 million patients were reviewed. The study population was classified into DME and non-DME cohorts. Primary and secondary outcomes were new-onset end-stage renal disease (ESRD) and all-cause mortality, respectively. Covariate factors were incorporated to reduce confounding effects.

RESULTS

Before matching, the DME cohort used more medication and had poorer renal function and blood sugar control than the non-DME cohort. Subsequently, the 2 groups were well-matched in demographics, socioeconomic status, lifestyle, comorbidities, and medication usage. The DME cohort had a significantly higher risk of ESRD, dialysis, and renal transplantation than the non-DME cohort. Subgroup analyses showed consistent results irrespective of follow-up duration, initial estimated glomerular filtration rate, or glycated hemoglobin levels. Additionally, the DME cohort had a lower risk of all-cause mortality than the non-DME cohort.

CONCLUSION

Statistically significant 5-year increased risks of ESRD, dialysis, and renal transplantation were observed in patients with concurrent DME. Therefore, close monitoring and follow-up of the renal function in DM patients with DME are necessary and strongly recommended.

Proteomic analysis of aqueous humor reveals novel regulators of diabetic macular edema

Diabetic macular edema (DME) is the most common cause of blindness in patients with diabetic retinopathy. To investigate the proteomic profiles of the aqueous humor (AH) of individuals with diabetic macular edema (DME), AH samples were collected from patients with non-diabetes mellitus (NDM), DM, nonproliferative diabetic retinopathy (NPDR), and DME. We performed comparative proteomic analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and bioinformatics analyses. We identified 425 proteins in these AH samples, of which 113 showed changes in expression in DME compared with NDM, 95 showed changes in expression in DME vs. DM, and 84 showed changes in expression in DME compared with NPDR. The bioinformatics analysis suggested that DME is closely associated with platelet degranulation, oxidative stress-related pathway, and vascular-related pathways. Upregulation of haptoglobin (HP) and downregulation of fibrillin 1 (FBN1) were validated by ELISA. Receiver operating characteristic (ROC) analysis showed that HP and FBN1 could distinguish DME from NPDR with areas under the curve of 0.987 (p = 0.00608) and 0.791 (p = 0.00629), respectively. The findings provide potential clues for further analysis of the molecular mechanisms and the development of new treatments for DME. HP and FBN1 may be potential key proteins and therapeutic targets in human DME. The proteomics dataset generated has been deposited to the ProteomeXchange/iProX Consortium with Identifier: PXD033404/IPX0004353001.

Recent Insights into the Etiopathogenesis of Diabetic Retinopathy and Its Management

Purpose: Diabetic retinopathy (DR) is a microvascular retinal disease associated with chronic diabetes mellitus, characterized by the damage of blood vessels in the eye. It is projected to become the leading cause of blindness, given the increasing burden of the diabetic population worldwide. The diagnosis and management of DR pose significant challenges for physicians because of the involvement of multiple biochemical pathways and the complexity of ocular tissues. This review aims to provide a comprehensive understanding of the molecular pathways implicated in the pathogenesis of DR, including the polyo pathway, hexosamine pathway, protein kinase C (PKC), JAK/STAT signaling pathways, and the renin-angiotensin system (RAS). Methods: Academic databases such as PubMed, Scopus, Google Scholar and Web of Science was systematically searched using a carefully constructed search strategy incorporating keywords like "Diabetic Retinopathy," "Molecular Pathways," "Pharmacological Treatments," and "Clinical Trials" to identify relevant literature for the comprehensive review. Results: In addition to activating other inflammatory cascades, these pathways contribute to the generation of oxidative stress within the retina. Furthermore, it aims to explore the existing pharmacotherapy options available for the treatment of DR. In addition to conventional pharmacological therapies such as corticosteroids, antivascular endothelial growth factors, and nonsteroidal anti-inflammatory drugs (NSAIDs), this review highlights the potential of repurposed drugs, phyto-pharmaceuticals, and novel pipeline drugs currently undergoing various stages of clinical trials. Conclusion: Overall, this review serves as a technical exploration of the complex nature of DR, highlighting both established and emerging molecular pathways implicated in its pathogenesis. Furthermore, it delves into the available pharmacological treatments, as well as the promising repurposed drugs, phyto-pharmaceuticals, and novel drugs currently being evaluated in clinical trials, with a focus on their specific mechanisms of action.

Artificial intelligence in retinal imaging: current status and future prospects

INTRODUCTION

The steadily growing and aging world population, in conjunction with continuously increasing prevalences of vision-threatening retinal diseases, is placing an increasing burden on the global healthcare system. The main challenges within retinology involve identifying the comparatively few patients requiring therapy within the large mass, the assurance of comprehensive screening for retinal disease and individualized therapy planning. In order to sustain high-quality ophthalmic care in the future, the incorporation of artificial intelligence (AI) technologies into our clinical practice represents a potential solution.

AREAS COVERED

This review sheds light onto already realized and promising future applications of AI techniques in retinal imaging. The main attention is directed at the application in diabetic retinopathy and age-related macular degeneration. The principles of use in disease screening, grading, therapeutic planning and prediction of future developments are explained based on the currently available literature.

EXPERT OPINION

The recent accomplishments of AI in retinal imaging indicate that its implementation into our daily practice is likely to fundamentally change the ophthalmic healthcare system and bring us one step closer to the goal of individualized treatment. However, it must be emphasized that the aim is to optimally support clinicians by gradually incorporating AI approaches, rather than replacing ophthalmologists.

Integration of systematic review, lipidomics with experiment verification reveals abnormal sphingolipids facilitate diabetic retinopathy by inducing oxidative stress on RMECs

OBJECTIVE

This study aims to explore the potential biomarkers in the development of diabetes mellitus (DM) into diabetic retinopathy (DR).

METHODS

Systematic review of diabetic metabolomics was used to screen the differential metabolites and related pathways during the development of DM. Non-targeted lipidomics of rat plasma was performed to explore the differential metabolites in the development of DM into DR in vivo. To verify the effects of differential metabolites in inducing retinal microvascular endothelial cells (RMECs) injury by increasing oxidative stress, high glucose medium containing differential metabolites was used to induce rat RMECs injury and cell viability, malondialdehyde (MDA) contents, superoxide dismutase (SOD) activities, reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were evaluated in vitro. Network pharmacology was performed to explore the potential mechanism of differential metabolites in inducing DR.

RESULTS

Through the systematic review, 148 differential metabolites were obtained and the sphingolipid metabolic pathway attracted our attention. Plasma non-targeted lipidomics found that sphingolipids were accompanied by the development of DM into DR. In vitro experiments showed sphinganine and sphingosine-1-phosphate aggravated rat RMECs injury induced by high glucose, further increased MDA and ROS levels, and further decreased SOD activities and MMP. Network pharmacology revealed sphinganine and sphingosine-1-phosphate may induce DR by regulating the AGE-RAGE and HIF-1 signaling pathways.

CONCLUSIONS

Integrated systematic review, lipidomics and experiment verification reveal that abnormal sphingolipid metabolism facilitates DR by inducing oxidative stress on RMECs. Our study could provide the experimental basis for finding potential biomarkers for the diagnosis and treatment of DR.

Evaluation of standard-of-care intravitreal aflibercept treatment practices in patients with diabetic macular oedema in the UK: DRAKO study outcomes

BACKGROUND/OBJECTIVES

DRAKO (NCT02850263) was a 24-month, prospective, non-interventional, multi-centre cohort study enrolling patients with diabetic macular oedema (DMO) including central involvement. The study evaluated UK standard-of-care intravitreal aflibercept (IVT-AFL) treatment. This analysis describes the treatment pathway and service provision for the anti-vascular endothelial growth factor (VEGF) treatment-naïve (C1) and non-naïve patients (C2) who received prior anti-VEGF treatment for DMO other than IVT-AFL.

METHODS

Mean changes in best-corrected visual acuity and central subfield thickness were measured and stratified by baseline factors, including ethnicity and administration of five initial monthly injections within predefined windows. Clinic visits were classified as treatment only (T1), monitoring assessment only (T2), combined visits (T3) or post-injection visits with no treatment or assessment (T4).

RESULTS

Median time from decision to treat to treatment was 6 days. As a percentage of total visits, T1, T2, T3 and T4 were 7%, 42%, 48% and 3% for C1 and 11%, 39%, 48% and 2% for C2. Most IVT-AFL injections were administered by healthcare professionals (HCPs) other than doctors (C1, 57.4%; C2, 58.5%). The percentage of treatments associated with a procedure-related adverse event where at least 75% of injections were completed by the same injector role were similar for doctors and other HCPs (C1, 1.1% and 0.8%; C2, 0.7%, and 1.0%).

CONCLUSIONS

Results indicate that upon DMO diagnosis, patients were treated promptly, and most visits were combined (treatment and assessment) or monitoring only. Most IVT-AFL was administered by non-physicians with a similar treatment-related safety profile as IVT-AFL administered by physicians.

COMPARATIVE ANALYSIS OF OCT AND OCT ANGIOGRAPHY CHARACTERISTICS IN EARLY DIABETIC RETINOPATHY

PURPOSE

To assess the quantitative characteristics of optical coherence tomography (OCT) and OCT angiography (OCTA) for the objective detection of early diabetic retinopathy (DR).

METHODS

This was a retrospective and cross-sectional study, which was carried out at a tertiary academic practice with a subspecialty. Twenty control participants, 15 people with diabetics without retinopathy (NoDR), and 22 people with mild nonproliferative diabetic retinopathy (NPDR) were included in this study. Quantitative OCT characteristics were derived from the photoreceptor hyperreflective bands, i.e., inner segment ellipsoid (ISe) and retinal pigment epithelium (RPE). OCTA characteristics, including vessel diameter index (VDI), vessel perimeter index (VPI), and vessel skeleton density (VSD), were evaluated.

RESULTS

Quantitative OCT analysis indicated that the ISe intensity was significantly trending downward with DR advancement. Comparative OCTA revealed VDI, VPI, and VSD as the most sensitive characteristics of DR. Correlation analysis of OCT and OCTA characteristics revealed weak variable correlation between the two imaging modalities.

CONCLUSION

Quantitative OCT and OCTA analyses revealed photoreceptor and vascular distortions in early DR. Comparative analysis revealed that the OCT intensity ratio, ISe/RPE, has the best sensitivity for early DR detection. Weak variable correlation of the OCT and OCTA characteristics suggests that OCT and OCTA are providing supplementary information for DR detection and classification.

An Explainable Fully Dense Fusion Neural Network with Deep Support Vector Machine for Retinal Disease Determination

Retinal issues are crucial because they result in visual loss. Early diagnosis can aid physicians in initiating treatment and preventing visual loss. Optical coherence tomography (OCT), which portrays retinal morphology cross-sectionally and noninvasively, is used to identify retinal abnormalities. The process of analyzing OCT images, on the other hand, takes time. This study has proposed a hybrid approach based on a fully dense fusion neural network (FD-CNN) and dual preprocessing to identify retinal diseases, such as choroidal neovascularization, diabetic macular edema, drusen from OCT images. A dual preprocessing methodology, in other words, a hybrid speckle reduction filter was initially used to diminish speckle noise present in OCT images. Secondly, the FD-CNN architecture was trained, and the features obtained from this architecture were extracted. Then Deep Support Vector Machine (D-SVM) and Deep K-Nearest Neighbor (D-KNN) classifiers were proposed to reclassify those features and tested on University of California San Diego (UCSD) and Duke OCT datasets. D-SVM demonstrated the best performance in both datasets. D-SVM achieved 99.60% accuracy, 99.60% sensitivity, 99.87% specificity, 99.60% precision and 99.60% F1 score in the UCSD dataset. It achieved 97.50% accuracy, 97.64% sensitivity, 98.91% specificity, 96.61% precision, and 97.03% F1 score in Duke dataset. Additionally, the results were compared to state-of-the-art works on the both datasets. The D-SVM was demonstrated to be an efficient and productive strategy for improving the robustness of automatic retinal disease classification. Also, in this study, it is shown that the unboxing of how AI systems' black-box choices is made by generating heat maps using the local interpretable model-agnostic explanation method, which is an explainable artificial intelligence (XAI) technique. Heat maps, in particular, may contribute to the development of more stable deep learning-based systems, as well as enhancing the confidence in the diagnosis of retinal disease in the analysis of OCT image for ophthalmologists.

Diabetic Macular Oedema Guidelines: An Australian Perspective

The number of people living with diabetes is expected to rise to 578 million by 2030 and to 700 million by 2045, exacting a severe socioeconomic burden on healthcare systems around the globe. This is also reflected in the increasing numbers of people with ocular complications of diabetes (namely, diabetic macular oedema (DMO) and diabetic retinopathy (DR)). In one study examining the global prevalence of DR, 35% of people with diabetes had some form of DR, 7% had PDR, 7% had DMO, and 10% were affected by these vision-threatening stages. In many regions of the world (Australia included), DR is one of the top three leading causes of vision loss amongst working age adults (20-74 years). In the management of DMO, the landmark ETDRS study demonstrated that moderate visual loss, defined as doubling of the visual angle, can be reduced by 50% or more by focal/grid laser photocoagulation. However, over the last 20 years, antivascular endothelial growth factor (VEGF) and corticosteroid therapies have emerged as alternative options for the management of DMO and provided patients with choices that have higher chances of improving vision than laser alone. In Australia, since the 2008 NHMRC guidelines, there have been significant developments in both the treatment options and treatment schedules for DMO. This working group was therefore assembled to review and address the current management options available in Australia.

Inclusion of diabetic retinopathy screening strategies in national-level diabetes care planning in low- and middle-income countries: a scoping review

BACKGROUND

Diabetes is a major public health concern, with approximately 80% of the burden falling on low- and middle-income countries (LMICs). Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes, and early detection through diabetic eye screening programmes is essential to prevent visual impairment and blindness. Careful planning at a national level is crucial for effective implementation of such programmes.

METHODS

A scoping review was conducted, and the protocol was published previously to explain the methods in detail. Data were collected from databases and searches, including grey literature. Furthermore, consultations were conducted with key informants from LMICs.

RESULTS

Lower-middle-income countries (29/50, 58%) and upper-middle-income countries (27/59, 45.8%) are making more progress than low-income countries (4/29, 13.8%) in terms of DR policy planning. However, no identified data for published policies have actually implemented national DR policies. Compared to low-income and lower-middle-income countries, upper-middle-income countries are making the most progress in implementing national diabetic eye screening programmes; however, their progress is still slow, with only 5/59 (8.5%) having such programmes.

CONCLUSION

There are significant gaps in the literature, with no data reported for 78/138 (56.5%) LMICs. Further research is clearly needed to support and document DR policy development in LMICs.

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

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

Functional and structural efficacy of a novel combinational therapy of aflibercept and timely focal/grid photocoagulation in diabetic macular oedema: do clinical study results compare favourably with a standard-of-care treated real-world population?

PURPOSE

To evaluate treatment efficacy in diabetic macular oedema (DME) comparing a study population receiving combined intravitreal vascular endothelial growth factor (VEGF) inhibition and focal/grid photocoagulation with a matched, real-world population receiving standard of care treatment.

METHODS

In an exploratory study, we included 43 eyes from 32 patients from a previously published study as well as 46 eyes from 38 standard-of-care patients. The study population had received a loading dose of three monthly aflibercept injections followed by focal/grid photocoagulation and additional aflibercept pro re nata. Principal measurements at 12 months were numbers of intravitreal injections, best corrected visual acuity (BCVA) and central retinal thickness (CRT).

RESULTS

At baseline, there were no differences between groups regarding age, sex, body mass index, haemoglobin A₁ C, systolic pressure or type of diabetes, but the study population had a higher diastolic pressure (81.6 versus 72.1 mmHg, p = 0.03) and a lower duration of diabetes (12.3 versus 23.2 years, p = 0.03). At month 12, patients in the study group had a higher visual acuity (79.6 versus 74.3 ETDRS letters, p = 0.03), despite having received fewer aflibercept injections (4.4 versus 5.9, p < 0.01) with a higher likelihood of having only received the three mandatory injections in the loading phase (39.5% versus 13.0%, p = 0.01).

CONCLUSION

In comparison to a matched, real-world DME-population, patients in combined treatment with intravitreal aflibercept and postloading focal/grid photocoagulation obtained a better functional outcome despite having received fewer intravitreal injections. Future randomized studies are needed to evaluate the long-term efficacy of this combined treatment regimen.

The role of the mTOR pathway in diabetic retinopathy

The retina, the part of the eye, translates the light signal into an electric current that can be sent to the brain as visual information. To achieve this, the retina requires fine-tuned vascularization for its energy supply. Diabetic retinopathy (DR) causes alterations in the eye vascularization that reduce the oxygen supply with consequent retinal neurodegeneration. During DR, the mammalian target of rapamycin (mTOR) pathway seems to coordinate retinal neurodegeneration with multiple anabolic and catabolic processes, such as autophagy, oxidative stress, cell death, and the release of pro-inflammatory cytokines, which are closely related to chronic hyperglycemia. This review outlines the normal anatomy of the retina and how hyperglycemia can be involved in the neurodegeneration underlying this disease through over activation or inhibition of the mTOR pathway.

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.

Wnt inhibitory factor 1 ameliorated diabetic retinopathy through the AMPK/mTOR pathway-mediated mitochondrial function

Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus and will lead to visual impairment. We aim to explore the effects and mechanisms of wnt inhibitory factor 1 (WIF1) in the progression of DR. To establish DR in vitro and in vivo, human retinal pigment epithelium (RPE) cell line ARPE-19 was treated with high-glucose (HG) and diabetic mice models were induced by streptozotocin (STZ), respectively. Different dose of recombinant WIF1 protein was used to treat DR. qRT-PCR and western blotting results demonstrated that WIF1 was downregulated, while VEGFA was upregulated in HG-induced ARPE-19 cells. WIF1 overexpression promoted cell migration. The ARPE-19 cells culture medium treated with WIF1 inhibited retinal endothelial cell tube formation and downregulated VEGFA expression. Moreover, WIF1 decreased the levels of ROS and MDA, while increasing the activity of SOD and GPX. WIF1 increased the ΔΨm in the mitochondria and downregulated the expression of mitochondrial autophagy-related proteins including Parkin, Pink1, LC3-II/LC3-I ratio, cleaved caspase 3, and cyt-c, which ameliorated mitochondrial dysfunction. The in vivo studies further demonstrated the consistent effects of WIF1 in STZ-induced mice. Taken together, WIF1 ameliorated mitochondrial dysfunction in DR by downregulating the AMPK/mTOR pathway.

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.

Management of Diabetic Macular Edema: Guidelines from the Emirates Society of Ophthalmology

In the United Arab Emirates, retinopathy has been shown to be present in 19% of the diabetic population, with diabetes identified in up to 40% of individuals aged over 55 years. Despite the prevalence of diabetic retinal diseases, there are no unified national guidelines on the management of diabetic macular edema (DME). These published guidelines are based on evidence taken from the literature and published trials of therapies, and consensus opinion of a representative expert panel with an interest in this condition, convened by the Emirates Society of Ophthalmology. The aim is to provide evidence-based, clinical guidance for the best management of different aspects of DME, with a special focus on vision-threatening diabetic retinopathy. Treatment should be initiated in patients with best-corrected visual acuity 20/30 or worse, and/or features of DME as seen on optical coherence tomography (OCT) with central retinal thickness (CRT) of at least 300 μm or in symptomatic patients with vision better than 20/25, and/or CRT less than 300 μm where there are OCT features consistent with center-involving macular edema. The treatment of DME is effective irrespective of glycated hemoglobin (HbA1c) level, and treatment must not be denied or delayed in order to optimize systemic parameters. All ophthalmic treatment options should be discussed with the patient for better compliance and expectations. Non-center-involving DME can be initially observed until progression toward the center is documented. Macular laser no longer has a primary role in center-involving DME, and anti-vascular endothelial growth factor (anti-VEGF) therapy should be considered as first-line treatment for all patients, unless contraindicated. If anti-VEGF is contraindicated, a steroid dexamethasone implant can be considered for first-line treatment. Recommendations for the treatment of DME in special circumstances and in relapsing and refractory DME are also discussed.

INCREASED DIETARY INTAKE AND SERUM LEVELS OF ADVANCED GLYCATION END PRODUCTS (AGES) ARE ASSOCIATED WITH DIABETIC MACULAR EDEMA

Aim

Diabetic macular oedema (DME) can develop at all stages of diabetic retinopathy, causing visual impairment and blindness. Modern diets are high in advanced glycation end products (dAGEs), derived from processing methods, exerting a pivotal role in promoting diabetic retinopathy risk. In present study, we investigate the relationship between dietary and serum levels of AGEs and DME in type 2 diabetic subjects.

Methods

This case-control study was conducted between July 2018 and February 2019 on 50 case subjects with DME and 40 healthy controls without DM without DME. The sociodemographic characteristics, nutritional status, and anthropometric measurements were evaluated. The advanced glycation end products (AGEs) and receptor for AGEs (sRAGE) levels in serum were analysed.

Results

The AGEs levels of the DME group were higher than in the control group (p <0.05). sRAGE levels were higher in the DME group, but not statistically significant (p >0.05). The dietary intake of AGEs was higher in the DME group (p <0.05). It was found that an increase in neck circumference increased the risk of DME (p <0.001).

Conclusion

A positive correlation was found between DME and AGEs, dAGE, neck circumference, and waist circumference. For the validity of these results, studies, including controlled nutrition interventions, are needed.

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.

Prediction of the Short-Term Therapeutic Effect of Anti-VEGF Therapy for Diabetic Macular Edema Using a Generative Adversarial Network with OCT Images

Purpose: To generate and evaluate individualized post-therapeutic optical coherence tomography (OCT) images that could predict the short-term response of anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) based on pre-therapeutic images using generative adversarial network (GAN). Methods: Real-world imaging data were collected at the Department of Ophthalmology, Qilu Hospital. A total of 561 pairs of pre-therapeutic and post-therapeutic OCT images of patients with DME were retrospectively included in the training set, 71 pre-therapeutic OCT images were included in the validation set, and their corresponding post-therapeutic OCT images were used to evaluate the synthetic images. A pix2pixHD method was adopted to predict post-therapeutic OCT images in DME patients that received anti-VEGF therapy. The quality and similarity of synthetic OCT images were evaluated independently by a screening experiment and an evaluation experiment. Results: The post-therapeutic OCT images generated by the GAN model based on big data were comparable to the actual images, and the response of edema resorption was also close to the ground truth. Most synthetic images (65/71) were difficult to differentiate from the actual OCT images by retinal specialists. The mean absolute error (MAE) of the central macular thickness (CMT) between the synthetic OCT images and the actual images was 24.51 ± 18.56 μm. Conclusions: The application of GAN can objectively demonstrate the individual short-term response of anti-VEGF therapy one month in advance based on OCT images with high accuracy, which could potentially help to improve treatment compliance of DME patients, identify patients who are not responding well to treatment and optimize the treatment program.

The inhibitory effects of Dulaglutide on cellular senescence against high glucose in human retinal endothelial cells

Diabetic nephropathy is one of the most important chronic microvascular complications of diabetes, and its main feature is diabetic glomerulosclerosis. Endothelial sirtuin 1 (SIRT1) expression is related to aging, and reducing SIRT1 expression promotes endothelial cell aging. Plasminogen activator inhibitor-1 (PAI-1) can be synthesized in a variety of cells, such as endothelial cells. Dulaglutide is a glucagon-like peptide-1 (GLP-1) drug, and it can activate the GLP-1 receptor and promote the conversion of intracellular adenosine triphosphate to adenylate cyclase, thereby activating phosphokinase A, and regulating blood glucose levels effectively in the body. We analyzed the effects of Dulaglutide on inhibiting cell senescence by studying the effects of its different concentrations on telomerase activity and senescence-related gene expression. Our results suggest that Dulaglutide can alleviate high-glucose-induced oxidative stress in human retinal endothelial cells by restoring the expressions of SIRT1 and endothelial nitric oxide synthase (eNOS), thereby inhibiting the expression of PAI-1, and restoring telomerase activity. This suggests that the activity of retinal endothelial cells can be controlled by regulating the expression of SIRT1, so as to achieve the effect of treating diabetic retinopathy.

Deep Learning Algorithm-Based MRI Image in the Diagnosis of Diabetic Macular Edema

This study investigates the value of magnetic resonance imaging (MRI) based on a deep learning algorithm in the diagnosis of diabetic macular edema (DME) patients. A total of 96 patients with DME were randomly divided into the experimental group (N  = 48) and the control group (N  = 48). A deep learning 3D convolutional neural network (3D-CNN) algorithm for MRI images of patients with DME was designed. The application value of this algorithm was comprehensively evaluated by MRI image segmentation Dice value, sensitivity, specificity, and other indicators and diagnostic accuracy. The results showed that the quality of MRI images processed by the 3D-CNN algorithm based on deep learning was significantly improved, and the Dice value, sensitivity, and specificity index data were significantly better than those of the traditional CNN algorithm (P < 0.05). In addition, the diagnostic accuracy of MRI images processed by this algorithm was 93.78 ± 5.32%, which was significantly better than the diagnostic accuracy of 64.25 ± 10.24% of traditional MRI images in the control group (P < 0.05). In summary, the 3D-CNN algorithm based on deep learning can significantly improve the accuracy and sensitivity of MRI image recognition and segmentation in patients with DME, can significantly improve the diagnostic accuracy of MRI in patients with DME, and has a good clinical application value.

Biochemical mechanism underlying the pathogenesis of diabetic retinopathy and other diabetic complications in humans: the methanol-formaldehyde-formic acid hypothesis

Hyperglycemia in diabetic patients is associated with abnormally-elevated cellular glucose levels. It is hypothesized that increased cellular glucose will lead to increased formation of endogenous methanol and/or formaldehyde, both of which are then metabolically converted to formic acid. These one-carbon metabolites are known to be present naturally in humans, and their levels are increased under diabetic conditions. Mechanistically, while formaldehyde is a cross-linking agent capable of causing extensive cytotoxicity, formic acid is an inhibitor of mitochondrial cytochrome oxidase, capable of inducing histotoxic hypoxia, ATP deficiency and cytotoxicity. Chronic increase in the production and accumulation of these toxic one-carbon metabolites in diabetic patients can drive the pathogenesis of ocular as well as other diabetic complications. This hypothesis is supported by a large body of experimental and clinical observations scattered in the literature. For instance, methanol is known to have organ- and species-selective toxicities, including the characteristic ocular lesions commonly seen in humans and non-human primates, but not in rodents. Similarly, some of the diabetic complications (such as ocular lesions) also have a characteristic species-selective pattern, closely resembling methanol intoxication. Moreover, while alcohol consumption or combined use of folic acid plus vitamin B is beneficial for mitigating acute methanol toxicity in humans, their use also improves the outcomes of diabetic complications. In addition, there is also a large body of evidence from biochemical and cellular studies. Together, there is considerable experimental support for the proposed hypothesis that increased metabolic formation of toxic one-carbon metabolites in diabetic patients contributes importantly to the development of various clinical complications.

Predictors of vision-related quality of life in patients with macular oedema receiving intra-vitreal anti-VEGF treatment

PURPOSE

To determine which demographic and clinical characteristics are predictive of vision-related quality of life (VrQoL) and quality of life (QoL) in patients with macular oedema receiving intravitreal anti-vascular endothelial growth factor (VEGF) treatment.

METHODS

Vision-related quality of life (VrQoL) and quality of life (QoL) were measured in 712 patients with retinal exudative disease receiving anti-VEGF treatment at baseline, 6 and 12 months. VrQoL was measured using an item-response theory based 47-question item bank (EyeQ), whereas QoL was measured using the EuroQol Five Dimensions (EQ-5D) questionnaire. The EQ-5D score was dichotomized into a perfect score of 1 and a suboptimal score of <1. Demographic and clinical patient characteristics were considered as possible predictors of (Vr)QoL. Prediction models for (Vr)QoL were created with linear mixed models and generalised estimating equations, using a forward selection procedure.

RESULTS

A worse VrQoL was predicted by poorer LogMAR visual acuity of the better eye, female sex, single civil status, older age, longer length of anti-VEGF treatment at baseline and the presence of non-ocular and ocular comorbidities. Suboptimal EQ-5D scores were predicted by poorer LogMAR visual acuity of the better eye, female sex, single civil status, older age, the presence of non-ocular comorbidities and a lower educational background.

CONCLUSIONS

Along with visual acuity of the better eye, which is the main factor used in clinical decision making, other patient characteristics should also be considered for the risk assessment of (Vr)QoL, such as sex, age, civil status, comorbidities and length of anti-VEGF treatment.

Changes in Macular Perfusion After ILUVIEN® Intravitreal Implant for Diabetic Macular Edema: An OCTA Study

INTRODUCTION

The aim of this study was to investigate changes in macular perfusion in patients affected by diabetic macular edema (DME) and treated with ILUVIEN® (fluocinolone acetonide intravitreal implant) 0.19 mg using optical coherence tomography angiography (OCTA).

METHODS

This was a retrospective cohort study that included patients aged > 18 years with type 2 non-proliferative diabetic retinopathy (DR) and DME at baseline. All patients were treated with the ILUVIEN® implant. A minimum of two 6 × 6-mm OCTA scans were required to ensure that all cases had a baseline OCTA and an OCTA performed at 4 months of follow-up. Qualitative and quantitative comparisons were performed.

RESULTS

Ten eyes from ten subjects were included in the analysis. Mean (± standard deviation) age of the study cohort was 57.1 ± 8.3 years. Mean parafoveal perfusion density (PD) at baseline was 64.1 ± 1.8% at baseline, increasing to 66.1 ± 2.9% (p = 0.013) at the 4-month follow-up visit. Mean parafoveal PD at baseline was 64.4 ± 2.1%, increasing to 65.2 ± 2.6% (p = 0.024) after 4 months. In the qualitative assessment, 60 regions (10 areas for each subject) were graded to assess changes in retinal perfusion between the baseline and follow-up visits. This assessment revealed that 24 regions (40.0%) were characterized by a qualitative increase in perfusion after treatment, while 22 (36.7%) and 14 (23.3%) regions were featured by a stability and reduction in retinal perfusion, respectively.

CONCLUSION

OCTA analysis detects improvements in macular perfusion after treatment with ILUVIEN®. This improvement in macular perfusion may be associated with corticosteroid-related beneficial effects on leukostasis.

Sulpiride-induced hyperprolactinaemia increases retinal vasoinhibin and protects against diabetic retinopathy in rats

Excessive vasopermeability and angiogenesis compromise vision in diabetic macular oedema (DME) and diabetic retinopathy (DR). Vasoinhibin is a fragment of the hormone prolactin (PRL) that inhibits diabetes-induced retinal hypervasopermeability and ischaemia-induced retinal angiogenesis in rodents. Hyperprolactinaemia generated by the dopamine D2 receptor antagonist, levosulpiride, is associated with higher levels of vasoinhibin in the vitreous of patients with DR, implying a beneficial outcome due to vasoinhibin-mediated inhibition of retinal vascular alterations. Here, we tested whether hyperprolactinaemia induced by racemic sulpiride increases intraocular vasoinhibin levels and inhibits retinal hypervasopermeability in diabetic rats. Diabetes was generated with streptozotocin and, 4 weeks later, rats were treated for 2 weeks with sulpiride or osmotic minipumps delivering PRL. ELISA, Western blot, and Evans blue assay were used to evaluate serum PRL, retinal vasoinhibin, and retinal vasopermeability, respectively. Hyperprolactinaemia in response to sulpiride or exogenous PRL was associated with increased levels of vasoinhibin in the retina and reduced retinal hypervasopermeability. Furthermore, sulpiride decreased retinal haemorrhages in response to the intravitreal administration of vascular endothelial growth factor (VEGF). Neither sulpiride nor exogenous PRL modified blood glucose levels or bodyweight. We conclude that sulpiride-induced hyperprolactinaemia inhibits the diabetes- and VEGF-mediated increase in retinal vasopermeability by promoting the intraocular conversion of endogenous PRL to vasoinhibin. These findings support the therapeutic potential of sulpiride and its levorotatory enantiomer, levosulpiride, against DME and DR.

Expression of Long Non-Coding RNA (lncRNA) SNHG5 in Patients with Refractory Diabetic Macular Edema and Its Regulatory Mechanism

BACKGROUND The aim of this study was to assess use of lncRNAs as biomarkers in serum and aqueous humor of patients with diabetic macular edema (DME). MATERIAL AND METHODS Optical coherence tomography and fundus photography were used to analyze the retinal features of the patients. RT-qPCR was used to analyze the differential expression of lncRNA snhg5 in patients who have idiopathic macular hole (MH), DME, or refractory DME. The relationship between SNHG5 and the clinical characteristics of the patients was analyzed. The effect of SNHG5 on the hyperplasia and apoptosis of human retino-microvascular endothelial cells (HRMECs) and its mechanism were analyzed in vitro. RESULTS Patients with idiopathic MH developed retinal nerve epithelium rupture and retinal fundus thickening, and patients with DME or refractory DME showed significant macular edema with hemorrhaging. The refractory DME patients improved after treatment but still showed significant macular edema and multiple laser scarring. SNHG5 expression was not only low in the atrial fluid and plasma in DME patients, but also lower in the refractory DME group compared to the idiopathic MH patients. SNHG5 expression in the aqueous humor and plasma was negatively correlated with disease duration, body mass index, and levels of fasting blood glucose, glycated hemoglobin, proteinuria, and glycosuria. In the in vitro experiments, SNHG5 expression was significantly downregulated in high glucose-induced HMECs. After SNHG5 overexpression, cell proliferation, angiogenesis, and VEGF-A protein levels were distinctly downregulated. CONCLUSIONS SNHG5 correlates with the development of DME and is a potential target for therapy.

Cataract Surgery Considerations for Diabetic Patients

PURPOSE OF REVIEW

Given the epidemiology and demographic trends of diabetes mellitus and cataracts, ophthalmologists are likely to encounter patients with both comorbidities at an increasing frequency. Patients with diabetes represent a higher risk population than healthy patients for cataract surgery. In this review, we discuss key risks and risk-mitigation practices when performing cataract surgery on these patients.

RECENT FINDINGS

Patients with diabetes continue to represent a high-risk surgical population: Nagar et al. suggest a dose-dependent relationship may exist between number of intravitreal injections and likelihood of posterior capsular rupture. However, novel treatments are improving outcomes for patients with diabetes. Several studies have reported intracameral phenylephrine/ketorolac may reduce the incidence of post-operative cystoid macular edema while others have discussed the efficacy of pre-treatment and post-treatment with intravitreal bevacizumab on improving cataract surgery outcomes in patients with diabetic retinopathy. Pre-operatively, ophthalmologists should perform an enhanced evaluation, consider timing and lens selection decisions, and complete any appropriate pre-operative treatment. Peri-operatively, surgeons should be aware of pupillary dilation adjustments, combination surgery options, and potential complications. Post-operatively, clinicians should address pseudophakic cystoid macular edema, diabetic macular edema, diabetic retinopathy, and posterior capsular opacification.

Gene-Based Therapeutics for Acquired Retinal Disease: Opportunities and Progress

Acquired retinal diseases such as age-related macular degeneration and diabetic retinopathy rank among the leading causes of blindness and visual loss worldwide. Effective treatments for these conditions are available, but often have a high treatment burden, and poor compliance can lead to disappointing real-world outcomes. Development of new treatment strategies that provide more durable treatment effects could help to address some of these unmet needs. Gene-based therapeutics, pioneered for the treatment of monogenic inherited retinal disease, are being actively investigated as new treatments for acquired retinal disease. There are significant advantages to the application of gene-based therapeutics in acquired retinal disease, including the presence of established therapeutic targets and common pathophysiologic pathways between diseases, the lack of genotype-specificity required, and the larger potential treatment population per therapy. Different gene-based therapeutic strategies have been attempted, including gene augmentation therapy to induce in vivo expression of therapeutic molecules, and gene editing to knock down genes encoding specific mediators in disease pathways. We highlight the opportunities and unmet clinical needs in acquired retinal disease, review the progress made thus far with current therapeutic strategies and surgical delivery techniques, and discuss limitations and future directions in the field.

Pediatric Diabetic Retinopathy: Updates in Prevalence, Risk Factors, Screening, and Management

PURPOSE OF REVIEW

Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus and a major cause of vision loss worldwide. The purpose of this review is to provide an update on the prevalence of diabetic retinopathy in youth, discuss risk factors, and review recent advances in diabetic retinopathy screening.

RECENT FINDINGS

While DR has long been considered a microvascular complication, recent data suggests that retinal neurodegeneration may precede the vascular changes associated with DR. The prevalence of DR has decreased in type 1 diabetes (T1D) patients following the results of the Diabetes Control and Complications Trial and implementation of intensive insulin therapy, with prevalence ranging from 14-20% before the year 2000 to 3.7-6% after 2000. In contrast, the prevalence of diabetic retinopathy in pediatric type 2 diabetes (T2D) is higher, ranging from 9.1-50%. Risk factors for diabetic retinopathy are well established and include glycemic control, diabetes duration, hypertension, and hyperlipidemia, whereas diabetes technology use including insulin pumps and continuous glucose monitors has been shown to have protective effects. Screening for DR is recommended for youth with T1D once they are aged ≥ 11 years or puberty has started and diabetes duration of 3-5 years. Pediatric T2D patients are advised to undergo screening at or soon after diagnosis, and annually thereafter, due to the insidious nature of T2D. Recent advances in DR screening methods including point of care and artificial intelligence technology have increased access to DR screening, while being cost-saving to patients and cost-effective to healthcare systems. While the prevalence of diabetic retinopathy in youth with T1D has been declining over the last few decades, there has been a significant increase in the prevalence of DR in youth with T2D. Improving access to diabetic retinopathy screening using novel screening methods may help improve detection and early treatment of diabetic retinopathy.

Ghrelin Ameliorates Diabetic Retinal Injury: Potential Therapeutic Avenues for Diabetic Retinopathy

Ghrelin has anti-inflammatory, antioxidant, and antiapoptotic effects, and it may be beneficial for the treatment of many ophthalmic diseases, such as cataract, uveitis, and glaucoma. Our previous work proved that ghrelin pretreatment reduced the apoptosis of lens epithelial cells induced by hydrogen peroxide, reduced the accumulation of reactive oxygen species (ROS), and effectively maintained the transparency of lens tissue. However, no study has yet investigated the effect of ghrelin on retina. In this study, we conducted in vitro and in vivo experiments to explore the effect of ghrelin on high-glucose- (HG-) induced ARPE-19 cell damage and diabetic retinopathy in streptozotocin-induced diabetic rats. ARPE-19 cells were incubated in a normal or an HG (30 mM glucose) medium with or without ghrelin. Cell viability was measured by 3-(4, 5-dimethylthiazol-3-yl)-2,5-diphenyl tetrazolium bromide assay, and apoptosis was detected by the Hoechst–PI staining assay. Intracellular reactive oxygen species (ROS) production levels within cells were measured using 2′,7′-dichlorofluorescein diacetate staining, and the contents of superoxide dismutase and malondialdehyde were measured using relevant detection kits. The expression levels of IL-1β and IL-18 were measured using an enzyme-linked immunosorbent assay, and those of NLRP3, IL-1β, and IL-18 were measured using Western blotting. The rat diabetes models were induced using a single intraperitoneal injection of streptozotocin (80 mg/kg). The morphological and histopathological changes in the retinal tissues were examined. The results indicated that ghrelin reduced ROS generation, inhibited cell apoptosis and the activation of NLRP3 inflammasome, inhibited the apoptosis of retinal cells in diabetic rats, and protected the retina against HG-induced dysfunction. In conclusion, ghrelin may play a role in the treatment of ocular diseases involving diabetic retinopathy.

Updates on the Current Treatments for Diabetic Retinopathy and Possibility of Future Oral Therapy

Diabetic retinopathy (DR) is a complication of diabetes and one of the leading causes of vision loss worldwide. Despite extensive efforts to reduce visual impairment, the prevalence of DR is still increasing. The initial pathophysiology of DR includes damage to vascular endothelial cells and loss of pericytes. Ensuing hypoxic responses trigger the expression of vascular endothelial growth factor (VEGF) and other pro-angiogenic factors. At present, the most effective treatment for DR and diabetic macular edema (DME) is the control of blood glucose levels. More advanced cases require laser, anti-VEGF therapy, steroid, and vitrectomy. Pan-retinal photocoagulation for non-proliferative diabetic retinopathy (NPDR) is well established and has demonstrated promising outcomes for preventing the progressive stage of DR. Furthermore, the efficacy of laser therapies such as grid and subthreshold diode laser micropulse photocoagulation (SDM) for DME has been reported. Vitrectomy has been performed for vitreous hemorrhage and tractional retinal detachment for patients with PDR. In addition, anti-VEGF treatment has been widely used for DME, and recently its potential to prevent the progression of PDR has been remarked. Even with these treatments, many patients with DR lose their vision and suffer from potential side effects. Thus, we need alternative treatments to address these limitations. In recent years, the relationship between DR, lipid metabolism, and inflammation has been featured. Research in diabetic animal models points to peroxisome proliferator-activated receptor alpha (PPARα) activation in cellular metabolism and inflammation by oral fenofibrate and/or pemafibrate as a promising target for DR. In this paper, we review the status of existing therapies, summarize PPARα activation therapies for DR, and discuss their potentials as promising DR treatments.

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

The elderly population in the United States is projected to almost double by the year 2050. In addition, the numbers of diabetics are rising, along with its most common complication, diabetic retinopathy (DR). To effectively treat DR within the elderly population, it is essential first to consider the retinal changes that occur due to aging, such as decreased blood flow, retinal thinning, and microglial changes, and understand that these changes can render the retina more vulnerable to oxidative and ischemic damage. Given these considerations, as well as the pathogenesis of DR, specific pathways could play a heightened role in DR progression in elderly patients, such as the polyol pathway and the vascular endothelial growth factor (VEGF) axis. Current ocular treatments include intravitreal corticosteroids, intravitreal anti-VEGF agents, laser photocoagulation and surgical interventions, in addition to better control of underlying diabetes with an expanding range of systemic treatments. While using therapeutics, it is also essential to consider how pharmacokinetics and pharmacodynamics change with aging; oral drug absorption can decrease, and ocular drug metabolism might affect the dosing and delivery methods. Also, elderly patients may more likely be nonadherent to their medication regimen or appointments than younger patients, and undertreatment with anti-VEGF drugs often leads to suboptimal outcomes. With a rising number of elderly DR patients, understanding how aging affects disease progression, pharmacological metabolism, and adherence are crucial to ensuring that this population receives adequate care.

Knowledge of ocular complications of diabetes in community-based people with type 2 diabetes: The Fremantle Diabetes Study II

AIMS

To assess knowledge of diabetes-related eye disease in Australians with type 2 diabetes and its associations with diabetic retinopathy (DR), other ocular complications and vision-related quality of life.

METHODS

A random sample from the Fremantle Diabetes Study Phase II cohort (n = 360) was invited to participate. Knowledge was assessed using 10 multiple-choice questions covering how diabetes affects the eyes, frequency of ophthalmic screening, risk factors, prevention, available treatments, and prognosis. DR was assessed from fundus photographs. Multiple linear regression was used to identify independent associates of the knowledge score (KS).

RESULTS

We included 264 participants (mean ± SD age 72.1 ± 9.2 years, 56.8% male, median [IQR] diabetes duration 15.4 [11.1-22.3] years). The mean ± SD KS out of 10 was 5.3 ± 1.8. Most (67%) participants knew diabetes can affect the eye and lead to blindness. Only 13.6% knew that DR screening intervals depend on risk factors. Those with moderate non-proliferative DR (NPDR) or worse had a better knowledge score (B = 1.37,P = 0.008) after adjusting for age (B = -0.03, P = 0.004) and education beyond primary school (B = 1.75, P < 0.001).

CONCLUSIONS

Overall knowledge of diabetes-related ocular complications was suboptimal. Education targeting eye disease may benefit people with type 2 diabetes who are older, less well educated and/or who have no DR/mild NPDR.

Significance of monitoring vascular endothelial growth factor, monocyte chemoattractant protein-1 and Interleukin-8 in diabetic macular edema towards early identification of nonresponders to ranibizumab therapy

Purpose:

Identification of nonresponders prior to anti-vascular endothelial growth factor (anti-VEGF) therapy would help in the judicious clinical management of diabetic macular edema (DME) patients. Thus, a systematic study was initiated to identify nonresponding DME patient population undergoing ranibizumab treatment to figure out additional inflammatory components that may contribute to their nonresponsiveness to anti-VEGF therapy.

Methods:

A total of 40 patients recruited to this investigator-initiated trial received intravitreal ranibizumab monthly for 3 months. The fourth- and fifth-month injections were according to PRN protocol and the sixth-month injection was mandatory. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and VEGF in aqueous humor were measured for all the patients. Patients were grouped into responders/nonresponders on the formulated criteria and the levels of key pro-inflammatory cytokines were also measured between the two groups at baseline, 2 month and 5 months using cytometric bead array (CBA).

Results:

Eleven patients were categorized (29.72%) as responders and 10 patients (27.02%) as nonresponders. Nonresponders showed poorer BCVA (P = 0.024, 0.045, and 0.048 for 4, 5, and 6 months) and higher CMT (P = 0.021, 0.0008 and <0.0001 for baseline, 1, 2, 3, 4, 5, and 6 months) compared to responders. The cytokines IL-8, MCP-1 were significantly up regulated (P = 0.0048 and 0.029 for MCP-1 and IL-8) in nonresponders.

Conclusion:

Elevated MCP-1 and IL-8 levels found in the nonresponders could be used as a prognostic marker to identify these groups of patients and can help in developing alternative treatment options along with anti-VEGF therapy.

Cross-attention multi-branch network for fundus diseases classification using SLO images

Fundus diseases classification is vital for the health of human beings. However, most of existing methods detect diseases by means of single angle fundus images, which lead to the lack of pathological information. To address this limitation, this paper proposes a novel deep learning method to complete different fundus diseases classification tasks using ultra-wide field scanning laser ophthalmoscopy (SLO) images, which have an ultra-wide field view of 180-200˚. The proposed deep model consists of multi-branch network, atrous spatial pyramid pooling module (ASPP), cross-attention and depth-wise attention module. Specifically, the multi-branch network employs the ResNet-34 model as the backbone to extract feature information, where the ResNet-34 model with two-branch is followed by the ASPP module to extract multi-scale spatial contextual features by setting different dilated rates. The depth-wise attention module can provide the global attention map from the multi-branch network, which enables the network to focus on the salient targets of interest. The cross-attention module adopts the cross-fusion mode to fuse the channel and spatial attention maps from the ResNet-34 model with two-branch, which can enhance the representation ability of the disease-specific features. The extensive experiments on our collected SLO images and two publicly available datasets demonstrate that the proposed method can outperform the state-of-the-art methods and achieve quite promising classification performance of the fundus diseases.

The contribution of dietary glycemic index and glycemic load to the development of microvascular complications of diabetes

Lifestyle modification, including a healthy diet, is of paramount importance in the management of diabetes mellitus. To this end, diets have been proposed with low glycemic index (an index of carbohydrate food expressing how quickly this nutrient can increase blood glucose) and glycemic load (an index obtained by multiplying the glycemic index by the grams of carbohydrate, then dividing by 100). The aim of this review was to discuss the potential contribution of diets with low glycemic index and glycemic load in diabetic microvascular complications. Currently, their role to the prevention and delay of microvascular complications in diabetes mellitus remains unclear, and further knowledge is desirable.

A dynamic nomogram for predicting diabetic macular edema in type 2 diabetes patients based on plasma cytokines

OBJECTIVE

This study investigated changes of plasma cytokines and aimed to build a dynamic nomogram for diabetic macular edema (DME) in type 2 diabetes mellitus (T2DM).

METHODS

In a pilot cohort, plasma samples were selected from 9 T2DM patients and 9 DME patients to screen for cytokine differences. The screening cytokines were then validated by enzyme-linked immunoassay in a cohort, which contained 100 DME (DME group) and 100 T2DM patients without DME (T2DM group). A dynamic nomogram for predicting DME was developed, based on the plasma cytokines.

RESULTS

In the pilot cohort, 11 plasma cytokines were significantly increased in the DME group. In the validation cohort, platelet-derived growth factor (PDGF)-BB, tissue inhibitors of metalloproteinase (TIMP)-1, angiopoietin (ANG-1), and vascular endothelial cell growth factor receptor (VEGFR)-2 were confirmed to be significantly elevated in the DME group. The dynamic nomogram demonstrated good calibration and discrimination, with an area under the receiver operating characteristic curve (AUC) of 0.88. In the test set, sensitivity, specificity, and AUC were 73.3%, 80.0%, and 0.84, respectively.

CONCLUSION

Plasma cytokines were closely associated with DME. A novel dynamic monogram including ANG-1, PDGF-BB, TIMP-1, and VEGFR2 was a novel tool for predicting DME.

EFFECTIVENESS OF EN BLOC REMOVAL OF FIBRINOGEN-RICH COMPONENT OF CYSTOID LESION FOR THE TREATMENT OF CYSTOID MACULAR EDEMA

PURPOSE

To introduce the methodology and outcomes of en bloc removal of the component of cystoid lesion during pars plana vitrectomy as a novel approach for the treatment of cystoid macular edema and show evidence that the component is an aggregation of fibrinogen by mass spectrometry analysis.

METHODS

The surgical en bloc extraction of the component of cystoid lesion was performed for cystoid macular edemas secondary to diabetic retinopathy and retinal vein occlusion. Perioperative change of best-corrected decimal visual acuity, and the central retinal thickness and the continuity of subfoveal ellipsoid zone and external limiting membrane on optical coherence tomography were evaluated. Mass spectrometry was performed for the identification of protein constituting the component.

RESULTS

Six eyes from six patients were included in the study. In all cases, central retinal thickness was improved after the surgery and remained stable during the follow-up period. Best-corrected decimal visual acuity and the continuity of ellipsoid zone and external limiting membrane were kept in all cases during the follow-up period. The mass spectrometry analysis disclosed that the component was composed of fibrinogen.

CONCLUSION

The en block removal of the component of cystoid lesion combined with pars plana vitrectomy may be a promising option for treatment of cystoid macular edema. The component of cystoid lesion is presumably a fibrinogen aggregate.

Role of Oxidative Stress and Severity of Diabetic Retinopathy in Type 1 and Type 2 Diabetes

BACKGROUND

Diabetic retinopathy (DR) is a sight-threatening complication of diabetes mellitus (DM). Oxidative stress generated on account of hyperglycemic state may lead to retinal abnormalities including DR.

OBJECTIVES

The aim of the study was to evaluate the status of antioxidant enzymes; superoxide dismutase (SOD), and catalase (CAT), in different stages of DR severity in subjects with type 1 DM (T1DM) and type 2 DM (T2DM).

METHODS

The cross-sectional study enrolled 148 subjects with T1DM (n = 17), T2DM (n = 96), and nondiabetic controls (n = 35). Subjects with DM were divided into 2 subgroups based on DR severity (mild-to-severe nonproliferative DR [NPDR] and proliferative DR [PDR]), and serum glycated hemoglobin (HbA1c), lipid profile, SOD, and CAT were estimated.

RESULTS

Both SOD and CAT levels were lower in diabetic subjects than nondiabetic controls. A significant positive correlation was found between HbA1C level and severity of DR (p < 0.0001). Levels of SOD and CAT varied significantly with DR severity in both diabetic groups at p < 0.05. Furthermore, levels of SOD and CAT were found to decrease significantly (p < 0.001) in DR (+) compared to DR (-) patients. Also, increased levels of HbA1c were significantly associated (p < 0.001) with decreased SOD in both subgroups (NPDR and PDR). DR severity was significantly associated with SOD and CAT in the NPDR and PDR subgroups (p < 0.05).

CONCLUSION

Oxidative stress and decreased antioxidant defenses are associated with DR progression to its PDR stage.

Non-invasive multimodal imaging of Diabetic Retinopathy: A survey on treatment methods and Nanotheranostics

Diabetes Retinopathy (DR) is one of the most prominent microvascular complications of diabetes. It is one of the pre-eminent causes for vision impairment followed by blindness among the working-age population worldwide. The de facto cause for DR remains challenging, despite several efforts made to unveil the mechanism underlying the pathology of DR. There is quite less availability of the low cost pre-emptive theranostic imaging tools in terms of in-depth resolution, due to the multiple factors involved in the etiology of DR. This review work comprehensively explores the various reports and research works on all perspectives of diabetic retinopathy (DR), and its mechanism. It also discusses various advanced non-destructive imaging modalities, current, and future treatment approaches. Further, the application of various nanoparticle-based drug delivery strategies used for the treatment of DR are also discussed. In a nutshell, the present review work bolsters the pursuit of the development of an advanced non-invasive optical imaging modal with a nano-theranostic approach for the future diagnosis and treatment of DR and its associated ocular complications.

Clinical Characteristics, Preventive Care and Attitude to Telemedicine among Patients with Diabetic Retinopathy: A Cross-Sectional Study

Diabetic retinopathy (DR) is the most frequent and one of the most severe complications of both types of diabetes. Despite the development of versatile diabetes management programs in most developed countries, many patients remain at increased risk for developing this life-limiting and life-threatening condition. This cross-sectional analysis objective was to examine and compare the prevalence of diabetic retinopathy and comorbidities, as well as the clinical characteristics, prevention patterns, and attitude to telemedicine in patients with diabetes. We found that, when compared to the non-DR group, patients with DR significantly more often utilize clinical preventive services and counseling; however, there is still a significant gap in the receipt of preventative care. Moreover, in the DR subgroup, inadequate diabetic control and the presence of various signs and symptoms of diseases were observed. Although less than a fifth of all patients use mobile applications to monitor their health status, the patients indicate their willingness to use telemedical technology, particularly if it is recommended by the physician and provided without additional costs. The evolution of telemedicine offers a possibility of inexpensive, continuous monitoring of the disease that could improve treatment outcomes. Our observations emphasize DR's perception as a complex disease in which education and continuous monitoring, particularly with telemedicine methods, are critical for further improvement in chronic care.

Increasing Incidence and Prevalence of Common Retinal Diseases in Retina Practices Across the United States

BACKGROUND AND OBJECTIVE

To provide an updated estimate of incidence and prevalence of the foremost retinal diseases in the U.S.

PATIENTS AND METHODS

Retrospective study of the Vestrum Health Database evaluating eyes with diagnoses of wet or dry age-related macular degeneration (AMD), diabetic macular edema (DME), diabetic retinopathy (DR), branch or central retinal vein occlusion (BRVO; CRVO) from January 2014 to December 2019 across 58 retina practices.

RESULTS

Of the 3,086,791 eyes examined, 490,881 (15.9%) had dry AMD, 294,041 (9.5%) wet AMD, 270,703 (8.8%) DME, 254,690 (8.3%) DR without DME, 73,617 (2.4%) BRVO, and 50,670 (1.6%) CRVO. Dry AMD had the highest incidence. These diseases comprised 61.0% of total prevalence and 54.3% of incidence among patients at the retina practices analyzed.

CONCLUSIONS

Based on a diverse database, these diseases comprised the majority of U.S. retina practice cases, with increasing annual incidences. AMD is the most common diagnosis, then diabetic eye disease. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:29-36.].

Associations between Vascular Endothelial Growth Factor Gene Polymorphisms and Different Types of Diabetic Retinopathy Susceptibility: A Systematic Review and Meta-Analysis

BACKGROUND

Vascular endothelial growth factor (VEGF) gene polymorphisms have been shown to be associated with the risk of diabetic retinopathy (DR), but the results were inconsistent. The aim of this study was to systematically assess the associations between VEGF gene polymorphisms and different types of DR (nonproliferative DR and proliferative DR).

METHODS

Electronic databases PubMed, Embase, Web of Science, CNKI, and WANFANG DATA were searched for articles on the associations between VEGF gene polymorphisms and different types of DR up to November 6, 2019. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and subgroup analyses were conducted by ethnicity. Sensitivity analysis was conducted to assess the stability of the results. Publication bias was assessed by using the Egger regression asymmetry test and visualization of funnel plots. A systematic review was conducted for polymorphisms with a high degree of heterogeneity (I ² > 75%) or studied in only one study.

RESULTS

A total of 13 and 18 studies analyzed the associations between VEGF SNPs and nonproliferative DR (NPDR) as well as proliferative DR (PDR), respectively. There were significant associations between rs2010963 and NPDR in Asian (dominant model: OR = 1.29, 95%CI = 1.04 - 1.60); and rs2010963 is associated with PDR in total population (dominant model: OR = 1.20, 95%CI = 1.03 - 1.41), either Asian (recessive model: OR = 1.57, 95%CI = 1.04 - 2.35) or Caucasian (recessive model: OR = 1.83, 95%CI = 1.28 - 2.63). Rs833061 is associated with PDR in Asian (recessive model: OR = 1.58, 95%CI = 1.11 - 2.26). Rs699947 is associated with NPDR in the total population (dominant model: OR = 2.04, 95%CI = 1.30 - 3.21) and associated with PDR in Asian (dominant model: OR = 1.72, 95%CI = 1.05 - 2.84).

CONCLUSIONS

Rs2010963, rs833061, and rs699947 are associated with NPDR or PDR, which may be involved in the occurrence and development of DR.