Background Diabetic Retinopathy Research Articles

Diagnostic accuracy of a smartphone-based device (VistaView) for detection of diabetic retinopathy: A prospective study

Background Diabetic retinopathy (DR) is a leading cause of blindness globally. The gold standard for DR screening is stereoscopic colour fundus photography with tabletop cameras. VistaView is a novel smartphone-based retinal camera which offers mydriatic retinal imaging. This study compares the diagnostic accuracy of the smartphone-based VistaView camera compared to a traditional desk mounted fundus camera (Triton Topcon). We also compare the agreement between graders for DR screening between VistaView images and Topcon images. Methodology This prospective study took place between December 2021 and June 2022 in Pakistan. Consecutive diabetic patients were imaged following mydriasis using both VistaView and Topcon cameras at the same sitting. All images were graded independently by two graders based on the International Classification of Diabetic Retinopathy (ICDR) criteria. Individual grades were assigned for severity of DR and maculopathy in each image. Diagnostic accuracy was calculated using the Topcon camera as the gold standard. Agreement between graders for each device was calculated as intraclass correlation coefficient (ICC) (95% CI) and Cohen’s weighted kappa (k). Principal findings A total of 1428 images were available from 371 patients with both cameras. After excluding ungradable images, a total of 1231 images were graded. The sensitivity of VistaView for any DR was 69.9% (95% CI 62.2–76.6%) while the specificity was 92.9% (95% CI 89.9–95.1%), and PPV and NPV were 80.5% (95% CI 73–86.4%) and 88.1% (95% CI 84.5–90.9) respectively. The sensitivity of VistaView for RDR was 69.7% (95% CI 61.7–76.8%) while the specificity was 94.2% (95% CI 91.3–96.1%), and PPV and NPV were 81.5% (95% CI 73.6–87.6%) and 89.4% (95% CI 86–92%) respectively. The sensitivity for detecting maculopathy in VistaView was 71.2% (95% CI 62.8–78.4%), while the specificity was 86.4% (82.6–89.4%). The PPV and NPV of detecting maculopathy were 63% (95% CI 54.9–70.5%) and 90.1% (95% CI 86.8–92.9%) respectively. For VistaView, the ICC of DR grades was 78% (95% CI, 75–82%) between the two graders and that of maculopathy grades was 66% (95% CI, 59–71%). The Cohen’s kappa for retinopathy grades of VistaView images was 0.61 (95% CI, 0.55–0.67, p<0.001), while that for maculopathy grades was 0.49 (95% CI 0.42–0.57, p<0.001). For images from the Topcon desktop camera, the ICC of DR grades was 85% (95% CI, 83–87%), while that of maculopathy grades was 79% (95% CI, 75–82%). The Cohen’s kappa for retinopathy grades of Topcon images was 0.68 (95% CI, 0.63–0.74, p<0.001), while that for maculopathy grades was 0.65 (95% CI, 0.58–0.72, p<0.001). Conclusion The VistaView offers moderate diagnostic accuracy for DR screening and may be used as a screening tool in LMIC.

PSAT1 is upregulated by METTL3 to attenuate high glucose-induced retinal pigment epithelial cell apoptosis and oxidative stress

BackgroundDiabetic retinopathy (DR) is a major ocular complication of diabetes mellitus, and a significant cause of visual impairment and blindness in adults. Phosphoserine aminotransferase 1 (PSAT1) is an enzyme participating in serine synthesis, which might improve insulin signaling and insulin sensitivity. Furthermore, it has been reported that the m6A methylation in mRNA controls gene expression under many physiological and pathological conditions. Nevertheless, the influences of m6A methylation on PSAT1 expression and DR progression at the molecular level have not been reported.MethodsHigh-glucose (HG) was used to treat human retinal pigment epithelial cells (ARPE-19) to construct a cell injury model. PSAT1 and Methyltransferase-like 3 (METTL3) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). PSAT1, B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), and METTL3 protein levels were examined by western blot assay. Cell viability and apoptosis were detected by Cell Counting Kit-8 (CCK-8) and TUNEL assays. Reactive oxygen species (ROS), malondialdehyde (MDA), and Glutathione peroxidase (GSH-Px) levels were examined using special assay kits. Interaction between METTL3 and PSAT1 was verified using methylated RNA immunoprecipitation (MeRIP) and dual-luciferase reporter assay.ResultsPSAT1 and METTL3 levels were decreased in DR patients and HG-treated ARPE-19 cells. Upregulation of PSAT1 might attenuate HG-induced cell viability inhibition and apoptosis and oxidative stress promotion in ARPE-19 cells. Moreover, PSAT1 was identified as a downstream target of METTL3-mediated m6A modification. METTL3 might improve the stability of PSAT1 mRNA via m6A methylation.ConclusionMETTL3 might mitigate HG-induced ARPE-19 cell damage partly by regulating the stability of PSAT1 mRNA, providing a promising therapeutic target for DR.

Association between myopia and diabetic retinopathy: A two-sample mendelian randomization study

ObjectiveThe association between myopia and diabetic retinopathy (DR) is unclear, with inconsistent results reported, and whether the association represents causality remains unknown. This study aimed to investigate the causal associations of genetically determined myopia with DR, and further explore specific mechanisms. MethodsWe conducted two-sample mendelian randomization (MR) analyses of any myopia and high myopia on six DR phenotypes, including any DR, background DR, severe background DR, proliferative DR (PDR), diabetic maculopathy and unspecific DR in the primary study. Mechanism exploration of spherical equivalent refraction (SER), corneal curvature (CC) and axial length (AL) on any DR was carried out subsequently. Single-nucleotide polymorphisms (SNPs), used as genetic instruments, were derived from UK Biobank, Genetic Epidemiology Research on Adult Health and Aging cohort and FinnGen. The inverse variance weighted (IVW) method was mainly used to assess the causality, and was complemented with sensitivity analyses and causality direction analyses. ResultsUsing SNPs that have excluded possible confounders, we discovered suggestive and positive causal associations of any myopia with any DR (IVW: odds ratio [OR] = 1.133, 95% confidence interval [95%CI]: 1.070–1.201, P = 1.91×10−5) and PDR (IVW: OR = 1.182, 95%CI: 1.088–1.285, P = 8.31×10−5). Similar but more significant associations were found of high myopia with any DR and PDR (IVW: OR = 1.107, 95%CI: 1.051–1.166, P = 1.39×10−4; OR = 1.163, 95%CI: 1.088–1.244, P = 8.76×10−6, respectively). Further mechanism analyses found only AL, rather than SER or CC, was strongly and significantly associated with any DR. These associations were robust in sensitivity analyses and causality direction analyses. ConclusionsWe found significant and positive causal associations of any myopia and high myopia with the risk of DR and PDR, which might be related with AL, indicating the significance of myopia control for preventing DR development and progression.

Prevalence and Risk Factors of Diabetic Retinopathy among Type 2 Diabetic Patients in Tertiary Care Hospital of Gandaki Province of Nepal

Background Diabetic retinopathy (DR) is one of the commonest causes of blindness in Nepal. This study aimed to determine the prevalence and risk factors of diabetic retinopathy in type 2 diabetic patients in a tertiary care hospital of Gandaki Province of Nepal. Methods This was a hospital based cross-sectional study conducted among 162 patients of type 2 diabetes aged 30 years and above. Standard proforma was used to collect socio-demographic and clinical variables of the patients. Detailed eye examination including fundus evaluation under mydriasis was done on all patients and diabetic retinopathy was classified according to Early Treatment of Diabetic Retinopathy Study Classification. Results The mean ±SD of age of the study sample was 61.99 ±11.69 years. The prevalence of diabetic retinopathy was 41.98%. Among the patients with diabetic retinopathy, the prevalence of mild NPDR, moderate NPDR, severe NPDR, very severe NPDR and PDR were 51.47%, 25%, 11.76%, 1.47%, and 10.29% respectively. There was statistically significant association of diabetic retinopathy with duration of diabetes and chronic kidney disease. However, there was no statistically significant association of diabetic retinopathy with gender, family history, hypertension, history of smoking, history of alcohol, treatment history and physical activity. Conclusions There is high prevalence of diabetic retinopathy among the diabetic patients. Longer duration of diabetes and chronic kidney disease were the significant risk factors for diabetic retinopathy. Early diagnosis and treatment of diabetic retinopathy is essential to reduce blindness in diabetic patients.

Indoxyl sulfate induces retinal microvascular injury via COX-2/PGE2 activation in diabetic retinopathy

BackgroundDiabetic retinopathy (DR), the principal cause of acquired blindness among the working-age population, is the most frequent microvascular complication of diabetes. Although metabolic disorders are hypothesized to play a role in its pathogenesis, the underlying mechanism remains largely elusive.MethodsTo elucidate the mechanism, we initially compared metabolite profiles of vitreous fluid between 23 patients with DR and 12 non-diabetic controls using liquid chromatography/tandem mass spectrometry, identifying the distinct metabolite indoxyl sulfate (IS). Subsequently, streptozotocin (STZ)-induced diabetic and IS-injected rat models were established to examine the effects of IS on retinal microvasculature. RNA sequencing was conducted to identify potential regulatory mechanisms in IS-treated human retinal endothelial cells (HREC). Finally, target gene knockdown in HREC and treatment of IS-injected rats with inhibitors (targeting IS production or downstream regulators) were employed to elucidate the detailed mechanisms and identify therapeutic targets for DR.ResultsMetabolomics identified 172 significantly altered metabolites in the vitreous humor of diabetics, including the dysregulated tryptophan metabolite indoxyl sulfate (IS). IS was observed to breach the blood-retinal barrier and accumulate in the intraocular fluid of diabetic rats. Both in vivo and in vitro experiments indicated that elevated levels of IS induced endothelial apoptosis and disrupted cell junctions. RNA sequencing pinpointed prostaglandin E2 (PGE2) synthetase-cyclooxygenase 2 (COX-2) as a potential target of IS. Validation experiments demonstrated that IS enhanced COX-2 expression, which subsequently increased PGE2 secretion by promoting transcription factor EGR1 binding to COX-2 DNA following entry into cells via organic anion transporting polypeptides (OATP2B1). Furthermore, inhibition of COX-2 in vivo or silencing EGR1/OATP2B1 in HREC mitigated IS-induced microcapillary damage and the activation of COX-2/PGE2.ConclusionOur study demonstrated that indoxyl sulfate (IS), a uremic toxin originating from the gut microbiota product indole, increased significantly and contributed to retinal microvascular damage in diabetic retinopathy (DR). Mechanistically, IS impaired retinal microvascular integrity by inducing the expression of COX-2 and the production of PGE2. Consequently, targeting the gut microbiota or the PGE2 pathway may offer effective therapeutic strategies for the treatment of DR.Graphical

α-Klotho prevents diabetic retinopathy by reversing the senescence of macrophages

BackgroundDiabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus (DM) and a significant cause of acquired blindness in the working-age population worldwide. Aging is considered as an important risk factor for DR development. Macrophages in aged mice bear typical M2 marker proteins but simultaneously express a pro-inflammatory factor profile. This may explain why the level of intraocular inflammation does not decrease during proliferative diabetic retinopathy (PDR) despite the occurrence of neovascularization and fibrosis (M2 activation). α-Klotho (KL) was originally discovered as a soluble anti-aging factor, which is mainly expressed in kidney tubular epithelium, choroid plexus in the brain and secreted in the blood. However, the role of KL in DR pathophysiology has not been previously reported.MethodsType 1 (streptozotocin [STZ]-induced) and type 2 (a high-fat diet along with a low dose of STZ) diabetic mouse models were established and injected with or without KL adenovirus via the tail vein for 12 weeks. Vldlr−/− mice were injected intravitreally with or without soluble KL protein from P8 to P15. The retinal structure and function were analyzed by electroretinogram and optical coherence tomography. The neovascular lesions were analyzed by retinal flat mount and RPE flat mount. The senescence markers, macrophage morphology, and KL expression levels were detected by immunofluorescence staining. A cell model was constructed using RAW264.7 cells stimulated by 4-hydroxynonenal (4HNE) and transfected with or without KL adenovirus. The senescence-associated secretory phenotypes were detected by qRT-PCR. Senescence was detected by SA-β-Gal staining. Serum, aqueous humor, and vitreous humor KL levels of proliferative diabetic retinopathy (PDR) patients were measured by enzyme‐linked immunosorbent assay. Quantitative proteomics and bioinformatics were applied to predict the change of proteins and biological function after overexpression of KL in macrophages. The effects of KL on the HECTD1 binding to IRS1 were analyzed by bioinformatics, molecular docking, and Western Blot.ResultsSerum, aqueous humor, and vitreous humor KL levels were lower in patients with PDR than in those with cataracts. KL relieved the retinal structure damage, improved retina function, and inhibited retinal senescence in diabetic mice. KL administration attenuated the neovascular lesions in VLDLR−/− mice by decreasing the secretion of VEGFA and FGF2 from macrophages. KL also protected RAW264.7 cells from 4HNE-induced senescence. Additionally, it inhibited E3 ubiquitin ligase HECTD1 expression in both diabetic mouse peripheral blood mononuclear cells and 4HNE-treated RAW264.7 cells. KL inhibited HECTD1 binding to IRS1 and reduced the ubiquitination of IRS1.ConclusionsMacrophage aging is involved in DM-induced retinopathy. KL alleviates DM-induced retinal macrophage senescence by downregulating HECTD1 and decreasing IRS1 ubiquitination and degradation. Meanwhile, KL administration attenuated the neovascular lesions by altering the activation state of macrophages and decreasing the expression of VEGFA and FGF2.

Artificial Intelligence in Detecting the Severity of Diabetic Retinopathy

BACKGROUND Diabetic retinopathy (DR) is the leading cause of visual impairment and blindness among individuals with diabetes mellitus. Early detection and timely intervention are crucial for preventing irreversible vision loss. However, traditional methods of DR screening are labor-intensive and reliant on the availability of skilled personnel, posing challenges in resource-constrained settings. Objective This study aims to evaluate the effectiveness of artificial intelligence (AI) in detecting the severity of DR compared to conventional ophthalmological assessments. METHODS A hospital-based observational study was conducted at the ophthalmology outpatient department of Tertiary care hospital, India over a six-month period. A total of 300 diabetic patients were included, and fundus photographs were obtained using a fundus camera. The images were then analyzed using an AI model trained on a diabetic retinopathy dataset. The severity of DR was graded according to established criteria, and the accuracy of the AI model was compared to that of ophthalmologist grading. RESULTS The AI model demonstrated an accuracy rate of 95.25% in grading the severity of DR. Comparison between AI and ophthalmologist grading showed close sensitivity and specificity rates across different DR grades, with the AI model slightly outperforming in certain categories. CONCLUSIONS Artificial intelligence shows promise as an effective and efficient tool for the screening and diagnosis of diabetic retinopathy. Its integration into healthcare systems could enhance early detection and treatment of DR, particularly in underserved regions with limited access to ophthalmological services. Further research and validation are warranted to optimize the use of AI in diabetic eye care and ensure its equitable distribution and ethical use.

Molecular mechanisms of Buqing granule for the treatment of diabetic retinopathy: Network pharmacology analysis and experimental validation.

Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. Its blindness rate is high; therefore, finding a reasonable and safe treatment plan to prevent and control DR is crucial. Currently, there are abundant and diverse research results on the treatment of DR by Chinese medicine Traditional Chinese medicine compounds are potentially advantageous for DR prevention and treatment because of its safe and effective therapeutic effects. To investigate the effects of Buqing granule (BQKL) on DR and its mechanism from a systemic perspective and at the molecular level by combining network pharmacology and in vivo experiments. This study collected information on the drug targets of BQKL and the therapeutic targets of DR for intersecting target gene analysis and protein-protein interactions (PPI), identified various biological pathways related to DR treatment by BQKL through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, and preliminarily validated the screened core targets by molecular docking. Furthermore, we constructed a diabetic rat model with a high-fat and high-sugar diet and intraperitoneal streptozotocin injection, and administered the appropriate drugs for 12 weeks after the model was successfully induced. Body mass and fasting blood glucose and lipid levels were measured, and pathological changes in retinal tissue were detected by hematoxylin and eosin staining. ELISA was used to detect the oxidative stress index expression in serum and retinal tissue, and immunohistochemistry, real-time quantitative reverse transcription PCR, and western blotting were used to verify the changes in the expression of core targets. Six potential therapeutic targets of BQKL for DR treatment, including Caspase-3, c-Jun, TP53, AKT1, MAPK1, and MAPK3, were screened using PPI. Enrichment analysis indicated that the MAPK signaling pathway might be the core target pathway of BQKL in DR treatment. Molecular docking prediction indicated that BQKL stably bound to these core targets. In vivo experiments have shown that compared with those in the Control group, rats in the Model group had statistically significant (P < 0.05) severe retinal histopathological damage; elevated blood glucose, lipid, and malondialdehyde (MDA) levels; increased Caspase-3, c-Jun, and TP53 protein expression; and reduced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels, ganglion cell number, AKT1, MAPK1, and MAPK3 protein expression. Compared with the Model group, BQKL group had reduced histopathological retinal damage and the expression of blood glucose and lipids, MDA level, Caspase-3, c-Jun and TP53 proteins were reduced, while the expression of SOD, GSH-Px level, the number of ganglion cells, AKT1, MAPK1, and MAPK3 proteins were elevated. These differences were statistically significant (P < 0.05). BQKL can delay DR onset and progression by attenuating oxidative stress and inflammatory responses and regulating Caspase-3, c-Jun, TP53, AKT1, MAPK1, and MAPK3 proteins in the MAPK signaling pathway mediates these alterations.

Impact of a diabetic retinal exam screening program on quality measure gaps at a family medicine practice

BackgroundDiabetic retinopathy is a common complication in people with diabetes, and annual screening is recommended by the American Diabetes Association. This annual exam is also a Health Effectiveness Data and Information Set quality measure. Barriers such as lack of access to healthcare or cost of specialist visits may impact the number of patients who receive these exams. ObjectiveThe objective of this study is to describe the impact of a diabetic retinal exam screening program at a rural family medicine center on the number of quality measure gaps resolved. Practice descriptionThis study occurred at a rural family medicine center in southwestern Pennsylvania with a medically underserved patient population. A pharmacist at the site holds board certifications in Advanced Diabetes Management and as a Diabetes Care and Education Specialist and manages diabetes through a collaborative practice agreement. Practice innovationA regional Medicaid plan provided a list of patients with a quality measure gap for an annual diabetic retinal exam and loaned a RetinaVue 700 Imager to take retinal photos. After screening eligible patients via phone, retinal exams were administered by student pharmacists and medical assistants to consenting patients over the course of 9 days. Images were then sent to an ophthalmologist to be interpreted. Evaluation methodsThe rate of quality measure gaps closed and satisfaction survey results are reported using descriptive statistics. ResultsA total of 61 patients were included in the analysis. This program closed quality measure gaps for 11 (18.0%) patients who were able to receive an in-office eye exam. ConclusionThis pilot project shows that offering in-office diabetic retinal exams may be an effective strategy to close quality measure gaps and provide access to screening among a medically underserved population.

Rapid tear screening of diabetic retinopathy by a detachable surface acoustic wave enabled immunosensor

BackgroundDiabetic retinopathy (DR), a chronic and progressive microvascular complication of diabetes mellitus, substantially threatens vision and is a leading cause of blindness among working-age individuals worldwide. Traditional diagnostic methods, such as ophthalmoscopy and fluorescein angiography are nonquantitative, invasive, and time consuming. Analysis of protein biomarkers in tear fluid offers noninvasive insights into ocular and systemic health, aiding in early DR detection. This study introduces a surface acoustic wave (SAW) microchip that rapidly enhances fluorescence in bead-based immunoassays for the sensitive and noninvasive DR detection from human tear samples. ResultsThe device facilitated particle mixing for immunoassay formation and particle concentration in the droplet, resulting in an enhanced immunofluorescence signal. This detachable SAW microchip allows the disposal of the cover glass after every use, thereby improving the reusability of the interdigital transducer and minimizing potential cross-contamination. A preliminary clinical test was conducted on a cohort of 10 volunteers, including DR patients and healthy individuals. The results demonstrated strong agreement with ELISA studies, validating the high accuracy rate of the SAW microchip. SignificanceThis comprehensive study offers significant insights into the potential application of a novel SAW microchip for the early detection of DR in individuals with diabetes. By utilizing protein biomarkers found in tear fluid, the device facilitates noninvasive, rapid, and sensitive detection, potentially revolutionizing DR diagnostics and improving patient outcomes through timely intervention and management of this vision-threatening condition.

Causal association between cystatin C and diabetic retinopathy: A two-sample Mendelian randomization study.

To explore the causal relationship between cystatin C levels and different stages of diabetic retinopathy through Mendelian randomization (MR). The MRC Integrative Epidemiology Unit provided the Genome-wide association studies (GWAS) data related to cystatin C (exposure). GWAS data for outcomes [DR, proliferative diabetic retinopathy (PDR), severe non-proliferative background diabetic retinopathy (SNPBDR)] were sourced from the FinnGen. Adopted Inverse Variance Weighting (IVW), MR-Egger regression MR-PRESSO, Weighted Median, Constrained Maximum Likelihood and Model Averaging (cML-MA), Weighted model, Radial MR, and MR-Lasso to estimate the causal relationship between cystatin C and diabetic retinopathy. We conducted multivariable MR analysis to evaluate the independent causal effects of cystatin C levels on diabetic retinopathy. Based on the IVW method, we observed a causal relationship between cystatin C and diabetic retinopathy [odds ratio (OR)random effect = 1.137, 95% confidence interval (CI): 1.035-1.250]/PDR (ORrandom effect = 1.123, 95%CI: 1.004-1.255)/SNPBDR (ORfixed effect = 2.002, 95%CI: 1.343-2.986). Consistent findings were obtained through the cML-MA method. Cochran's Q test suggested the presence of heterogeneity between the cystatin C level and instrumental variables in relation to diabetic retinopathy and proliferative diabetic retinopathy, respectively. After adjusting for outliers using MR-PRESSO and Radial MR, it was observed that the statistical significance of the association between cystatin C level and diabetic retinopathy persists. Reverse MR analysis indicated that genetically related SNPBDR may influence the cystatin C level. In multivariable MR analysis, there were indications suggesting a causal relationship of cystatin C with the risk of DR/PDR/SNPBDR adjusting for confounders. This study utilizes Mendelian randomization analyses to establish a causal relationship between cystatin C and diabetic retinopathy, and reveals the impact of cystatin C on the risk of diabetic retinopathy, thus providing new evidence for clinical intervention of diabetic retinopathy.

Vitamin D deficiency and the risk of diabetic retinopathy in patients with type 2 diabetes in Tibet: a cross-sectional analysis

BackgroundDiabetic retinopathy (DR) is one of the most common complications of diabetes worldwide. The aim of this study was to assess the prevalence of DR in hospitalized patients with type 2 diabetes (T2DM) in Tibet and to identify risk factors that may influence the occurrence of DR.MethodsThis was a cross-sectional study conducted in a third-class hospital in the Tibet Autonomous Region. The prevalence of DR in hospitalized patients with T2DM was measured. Univariate and multivariate logistic regression, restricted cubic spline (RCS) analysis and receiver-operating characteristic curve analysis were used to investigate the risk factors for DR.ResultsThe prevalence of DR was 29.3%. The duration of diabetes; concentrations of 25-OH-VitD3, hemoglobin, fasting insulin, alanine aminotransferase, total bilirubin, and creatinine; and HOMA-IR were significantly different between DR patients and non-DR patients (all P < 0.05). Univariate and multivariate logistic regression revealed that a longer duration of diabetes and lower 25-OH-VitD3 levels were associated with increased DR risk. RCS analysis suggested overall positive associations of the duration of diabetes and 25-OH-VitD3 concentrations with DR risk (P nonlinearity < 0.05). The turning points for the duration of diabetes and 25-OH-VitD3 concentrations were 5.1 years and 10.6 ng/mL, respectively. The sensitivity, specificity, and area under the receiver-operating characteristic curve for the combination of the duration of diabetes and 25-OH-VitD3 levels were 79.4%, 69.4% and 0.764, respectively.ConclusionsGiven the high prevalence of DR in hospitalized patients with T2DM in Tibet, vitamin D supplementation seems to be important in the prevention of DR to some degree.

Study of the Relationship between Diabetic Retinopathy, Basal Insulin Therapy (Glargine or NPH) and Insulin-Like Growth Factor 1 Serum Level

Abstract Background Diabetic retinopathy (DR) is the major cause of preventable blindness worldwide. DR is a microvascular complication of diabetes mellitus that is more prevalent in patients with type 1 diabetes. Type 1 diabetes mellitus is an autoimmune disease that leads to insulin deficiency so patients require long term therapy with basal insulin for optimum glycemic control. Insulin- like growth factor 1 (IGF-1) is an important growth factor that is involved in cell proliferation and angiogenesis. There is a lot of evidence that IGF-1 is tightly related to DR development. Insulin Glargine is a long-acting insulin analogue which is peak-free and less hypoglycemic as compared to the intermediate-acting NPH insulin. Glargine has an increased affinity to IGF-1 receptor and this raised concern about its role in development of DR. The relationship between diabetic retinopathy, basal insulin therapy and IGF-1 serum level is still in debate. Aim we aimed to compare the incidence and severity of diabetic retinopathy in type 1 diabetic patients on basal insulin therapy (Glargine or NPH) and its relation to serum IGF-1 level. Methods The current study included 88 subjects with type 1 diabetes divided into 44 on basal insulin therapy with Glargine and actrapid ( Group A) and 44 on NPH and actrapid ( Group B). Hemoglobin A1c, Total cholesterol, Triglycerides, High density lipoproteins, Low density lipoproteins and serum IGF-1 levels were assessed. Full clinical examination including (weight, height, BMI), vital signs (pulse, blood pressure) was done and Fundus examination by Optomed Aurora® IQ handheld fundus camera. Results On comparing the 2 studied groups, There was no statistical significant difference as regarding fundus examination findings between studied groups (P value = 0.429). There was no statistically significant relation between diabetic retinopathy and serum IGF-1 (P value = .080 with Mean ± SD of serum IGF-1 level in patients with Normal fundus 14.8 ± 11 vs. Patients with Diabetic retinopathy 21.3 ± 16.9). There was statistically significant association between diabetic retinopathy and duration of diabetes (P value&amp;lt; 0.05 with Mean ± SD of diabetes duration in patients with Diabetic retinopathy 17.7 ± 6.9 vs. Patients with Normal fundus 14.6 ± 5.6). There was a statistical significant difference as regarding age (P value&amp;lt; 0.05 with Mean ± SD of age in Group B regimen 28.4 ± 6.7 vs. Group A 25.5 ± 4.9). Conclusion Serum IGF-1 levels showed no statistically significant difference in patients either on Glargine or NPH and also in patients either with normal fundus or with diabetic retinopathy. The incidence and severity of diabetic retinopathy in patients with type 1 diabetes mellitus is directly proportionate to duration of disease. No noted difference concerning diabetic retinopathy changes between patients on basal insulin therapy either Glargine or NPH.

Perception of patients with retinal pathology on aspects of visual function and their management

Background and objectiveAge-related macular degeneration (AMD) and diabetic retinopathy (DR) are highly prevalent. ObjectiveTo explore perceptions of patients with AMD or DR about the impact of the disease and treatment on their daily living activities. Materials and methodsSemi-structured interviews with a questionnaire developed from validated patient reported outcomes questionnaires. The questionnaire consisted of 19 questions about the disease and 9 about the treatment. The questions (items) were answered on a scale from 1 to 9. In addition, the patient interviewed was invited to make free comments on each question. Nine patients with AMD and 9 with DR were interviewed by videoconference or telephone call. A quantitative analysis of the responses and a qualitative analysis of the comments were carried out. ResultsThe most relevant item for patients with AMD or DR is “Recognize people when they are nearby”, and “Read text in normal size font in a newspaper or book”, followed, in patients with AMD, by “Do things what you would like” and, in patients with DR, “Feeling frustrated by the vision problems.” Regarding the treatment, the most relevant aspects for both groups is that the treatment works and receiving appropriate information before and after the treatment. The qualitative comments were focused to the disease, the treatment, and to the role of doctors and the health system. ConclusionQuantitative responses and free comments can be useful to improve the care of patients with AMD or DR by physicians and the health system.

The association of chronic complications with time in tight range and time in range in people with type 1 diabetes: a retrospective cross-sectional real-world study.

The aim of this study was to evaluate the association of chronic complications with time in tight range (TITR: 3.9-7.8 mmol/l) and time in range (TIR: 3.9-10.0 mmol/l) in people with type 1 diabetes. The prevalence of microvascular complications (diabetic retinopathy, diabetic nephropathy and diabetic peripheral neuropathy [DPN]) and macrovascular complications according to sensor-measured TITR/TIR was analysed cross-sectionally in 808 adults with type 1 diabetes. Binary logistic regression was used to evaluate the association between TITR/TIR and the presence of complications without adjustment, with adjustment for HbA1c, and with adjustment for HbA1c and other confounding factors (sex, age, diabetes duration, BMI, BP, lipid profile, smoking, and use of statins and renin-angiotensin-aldosterone system inhibitors). The mean TITR and TIR were 33.9 ± 12.8% and 52.5 ± 15.0%, respectively. Overall, 46.0% had any microvascular complication (34.5% diabetic retinopathy, 23.8% diabetic nephropathy, 16.0% DPN) and 16.3% suffered from any macrovascular complication. The prevalence of any microvascular complication, diabetic retinopathy, diabetic nephropathy and a cerebrovascular accident (CVA) decreased with increasing TITR/TIR quartiles (all ptrend<0.05). Each 10% increase in TITR was associated with a lower incidence of any microvascular complication (OR 0.762; 95% CI 0.679, 0.855; p<0.001), diabetic retinopathy (OR 0.757; 95% CI 0.670, 0.856; p<0.001), background diabetic retinopathy (OR 0.760; 95% CI 0.655, 0.882; p<0.001), severe diabetic retinopathy (OR 0.854; 95% CI 0.731, 0.998; p=0.048), diabetic nephropathy (OR 0.799; 95% CI 0.699, 0.915; p<0.001), DPN (OR 0.837; 95% CI 0.717, 0.977; p=0.026) and CVA (OR 0.651; 95% CI 0.470, 0.902; p=0.010). The independent association of TITR with any microvascular complication (OR 0.867; 95% CI 0.762, 0.988; p=0.032), diabetic retinopathy (OR 0.837; 95% CI 0.731, 0.959; p=0.010), background diabetic retinopathy (OR 0.831; 95% CI 0.705, 0.979; p=0.027) and CVA (OR 0.619; 95% CI 0.426, 0.899; p=0.012) persisted after adjustment for HbA1c. Similar results were obtained when controlling for HbA1c and other confounding factors. TITR and TIR are inversely associated with the presence of microvascular complications and CVA in people with type 1 diabetes. Although this study was not designed to establish a causal relationship, this analysis adds validity to the use of TITR and TIR as key measures in glycaemic management. ClinicalTrials.gov NCT02601729 and NCT02898714.

A pilot cost-analysis study comparing AI-based EyeArt® and ophthalmologist assessment of diabetic retinopathy in minority women in Oslo, Norway

BackgroundDiabetic retinopathy (DR) is the leading cause of adult blindness in the working age population worldwide, which can be prevented by early detection. Regular eye examinations are recommended and crucial for detecting sight-threatening DR. Use of artificial intelligence (AI) to lessen the burden on the healthcare system is needed.PurposeTo perform a pilot cost-analysis study for detecting DR in a cohort of minority women with DM in Oslo, Norway, that have the highest prevalence of diabetes mellitus (DM) in the country, using both manual (ophthalmologist) and autonomous (AI) grading. This is the first study in Norway, as far as we know, that uses AI in DR- grading of retinal images.MethodsOn Minority Women’s Day, November 1, 2017, in Oslo, Norway, 33 patients (66 eyes) over 18 years of age diagnosed with DM (T1D and T2D) were screened. The Eidon - True Color Confocal Scanner (CenterVue, United States) was used for retinal imaging and graded for DR after screening had been completed, by an ophthalmologist and automatically, using EyeArt Automated DR Detection System, version 2.1.0 (EyeArt, EyeNuk, CA, USA). The gradings were based on the International Clinical Diabetic Retinopathy (ICDR) severity scale [1] detecting the presence or absence of referable DR. Cost-minimization analyses were performed for both grading methods.Results33 women (64 eyes) were eligible for the analysis. A very good inter-rater agreement was found: 0.98 (P < 0.01), between the human and AI-based EyeArt grading system for detecting DR. The prevalence of DR was 18.6% (95% CI: 11.4–25.8%), and the sensitivity and specificity were 100% (95% CI: 100–100% and 95% CI: 100–100%), respectively. The cost difference for AI screening compared to human screening was $143 lower per patient (cost-saving) in favour of AI.ConclusionOur results indicate that The EyeArt AI system is both a reliable, cost-saving, and useful tool for DR grading in clinical practice.

NSUN2 affects diabetic retinopathy progression by regulating MUC1 expression through RNA m5C methylation

BackgroundDiabetic retinopathy (DR) is the leading cause of blinding eye disease among working adults and is primarily attributed to the excessive proliferation of microvessels, which leads to vitreous hemorrhage and retinal traction, thereby significantly impairing patient vision. NSUN2-mediated RNA m5C methylation is implicated in various diseases, and in this investigation, we focused on elucidating the impact of NSUN2 on the regulation of the expression of the downstream gene MUC1, specifically through RNA m5C methylation, on the progression of DR.MethodUtilizing Microarray analysis, we examined patient vitreous fluid to pinpoint potential therapeutic targets for DR. Differential expression of NSUN2 was validated through qRT-PCR, Western blot, and immunofluorescence in human tissue, animal tissue, and cell model of DR. The relationship between NSUN2 and DR was explored in vitro and in vivo through gene knockdown and overexpression. Various techniques, such as MeRIP-qPCR and dot blot, were applied to reveal the downstream targets and mechanism of action of NSUN2.ResultsThe levels of both NSUN2 and RNA m5C methylation were significantly elevated in the DR model. Knockdown of NSUN2 mitigated DR lesion formation both in vitro and in vivo. Mechanistically, NSUN2 promoted MUC1 expression by binding to the RNA m5C reader ALYREF. Knockdown of ALYREF resulted in DR lesion alterations similar to those observed with NSUN2 knockdown. Moreover, MUC1 overexpression successfully reversed a series of DR alterations induced by NSUN2 silencing.ConclusionsNSUN2 regulates the expression of MUC1 through ALYREF-mediated RNA m5C methylation, thereby regulating the progression of DR and providing a new option for the treatment of DR in the future.

Nerolidol Alleviates Oxidative Stress and Inflammation in Diabetic Retinopathy Mediated by High Glucose through Ameliorating Nrf2/HO-1 Pathway

Background Diabetic retinopathy (DR) is the foremost microvascular problem that causes drastic visual impairment in diabetes patients. Hyperglycemia-triggered reaction cascade of inflammation and oxidative stress constitute the DR pathogenesis. The existing treatment options are not completely satisfactory. Materials and Methods We investigated the cell viability by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, inflammatory mediators, lactate dehydrogenase (LDH), superoxide dismutase, glutathione, and malonaldehyde (MDA) levels by ELISA and qRT-PCR assay, protein expression of Nrf2 and heme oxygenase-1 (HO-1) by western blotting assay were analyzed. Results According to our research, nerolidol (NRD) increases the proliferation and antioxidant activity of human retinal endothelial cells (HRECs) by inducing Nrf2/HO-1 signaling, while attenuating MDA, an oxidative stress marker, LDH, and inflammatory mediators. These outcomes suggest that a substantial reaction of inflammation and oxidative stress injury happened in DR, which might be correlated to the instigation of the signaling Nrf2/HO-1. Conclusion NRD effectively suppresses oxidative stress and inflammation in HG-induced HRECs. The primary mechanism of NRD on DR may be linked to the activation of the Nrf2/HO-1 pathway and may give a useful medicine for DR treatment.

Cellular communication network factor 1 promotes retinal leakage in diabetic retinopathy via inducing neutrophil stasis and neutrophil extracellular traps extrusion

BackgroundDiabetic retinopathy (DR) is a major cause of blindness and is characterized by dysfunction of the retinal microvasculature. Neutrophil stasis, resulting in retinal inflammation and the occlusion of retinal microvessels, is a key mechanism driving DR. These plugging neutrophils subsequently release neutrophil extracellular traps (NETs), which further disrupts the retinal vasculature. Nevertheless, the primary catalyst for NETs extrusion in the retinal microenvironment under diabetic conditions remains unidentified. In recent studies, cellular communication network factor 1 (CCN1) has emerged as a central molecule modulating inflammation in pathological settings. Additionally, our previous research has shed light on the pathogenic role of CCN1 in maintaining endothelial integrity. However, the precise role of CCN1 in microvascular occlusion and its potential interaction with neutrophils in diabetic retinopathy have not yet been investigated.MethodsWe first examined the circulating level of CCN1 and NETs in our study cohort and analyzed related clinical parameters. To further evaluate the effects of CCN1 in vivo, we used recombinant CCN1 protein and CCN1 overexpression for gain-of-function, and CCN1 knockdown for loss-of-function by intravitreal injection in diabetic mice. The underlying mechanisms were further validated on human and mouse primary neutrophils and dHL60 cells.ResultsWe detected increases in CCN1 and neutrophil elastase in the plasma of DR patients and the retinas of diabetic mice. CCN1 gain-of-function in the retina resulted in neutrophil stasis, NETs extrusion, capillary degeneration, and retinal leakage. Pre-treatment with DNase I to reduce NETs effectively eliminated CCN1-induced retinal leakage. Notably, both CCN1 knockdown and DNase I treatment rescued the retinal leakage in the context of diabetes. In vitro, CCN1 promoted adherence, migration, and NETs extrusion of neutrophils.ConclusionIn this study, we uncover that CCN1 contributed to retinal inflammation, vessel occlusion and leakage by recruiting neutrophils and triggering NETs extrusion under diabetic conditions. Notably, manipulating CCN1 was able to hold therapeutic promise for the treatment of diabetic retinopathy.

Comparison of 21 artificial intelligence algorithms in automated diabetic retinopathy screening using handheld fundus camera

Background Diabetic retinopathy (DR) is a common complication of diabetes and may lead to irreversible visual loss. Efficient screening and improved treatment of both diabetes and DR have amended visual prognosis for DR. The number of patients with diabetes is increasing and telemedicine, mobile handheld devices and automated solutions may alleviate the burden for healthcare. We compared the performance of 21 artificial intelligence (AI) algorithms for referable DR screening in datasets taken by handheld Optomed Aurora fundus camera in a real-world setting. Patients and methods Prospective study of 156 patients (312 eyes) attending DR screening and follow-up. Both papilla- and macula-centred 50° fundus images were taken from each eye. DR was graded by experienced ophthalmologists and 21 AI algorithms. Results Most eyes, 183 out of 312 (58.7%), had no DR and mild NPDR was noted in 21 (6.7%) of the eyes. Moderate NPDR was detected in 66 (21.2%) of the eyes, severe NPDR in 1 (0.3%), and PDR in 41 (13.1%) composing a group of 34.6% of eyes with referable DR. The AI algorithms achieved a mean agreement of 79.4% for referable DR, but the results varied from 49.4% to 92.3%. The mean sensitivity for referable DR was 77.5% (95% CI 69.1–85.8) and specificity 80.6% (95% CI 72.1–89.2). The rate for images ungradable by AI varied from 0% to 28.2% (mean 1.9%). Nineteen out of 21 (90.5%) AI algorithms resulted in grading for DR at least in 98% of the images. Conclusions Fundus images captured with Optomed Aurora were suitable for DR screening. The performance of the AI algorithms varied considerably emphasizing the need for external validation of screening algorithms in real-world settings before their clinical application.