Proliferative Diabetic Retinopathy Patients Research Articles

Upregulation of HMOX1 associated with M2 macrophage infiltration and ferroptosis in proliferative diabetic retinopathy

The roles of immune cell infiltration and ferroptosis in the progression of proliferative diabetic retinopathy (PDR) remain unclear. To identify upregulated molecules associated with immune infiltration and ferroptosis in PDR, GSE60436 and GSE102485 datasets were downloaded from the Gene Expression Omnibus (GEO). Genes associated with immune cell infiltration were examined through Weighted Gene Co-expression Network Analysis (WGCNA) and CIBERSORT algorithm. Common differentially expressed genes (DEGs) were intersected with ferroptosis-associated and immune cell infiltration-related genes. Localization of cellular expression was confirmed by single-cell analysis of GSE165784 dataset. Findings were validated by qRT-PCR, ELISA, Western blotting, and immunofluorescence staining. As a result, the infiltration of M2 macrophages was significantly elevated in fibrovascular membrane samples from PDR patients than the retinas of control subjects. Analysis of DEGs, M2 macrophage-related genes and ferroptosis-related genes identified three hub intersecting genes, TP53, HMOX1 and PPARA. qRT-PCR showed that HMOX1 was significantly higher in the oxygen-induced retinopathy (OIR) mouse model retinas than in controls. Single-cell analysis confirmed that HMOX1 was located in M2 macrophages. ELISA and western blotting revealed elevated levels of HMOX1 in the vitreous humor of PDR patients and OIR retinas, and immunofluorescence staining showed that HMOX1 co-localized with M2 macrophages in the retinas of OIR mice. This study offers novel insights into the mechanisms associated with immune cell infiltration and ferroptosis in PDR. HMOX1 expression correlated with M2 macrophage infiltration and ferroptosis, which may play a crucial role in PDR pathogenesis.

Exosomal lncRNA-MIAT promotes neovascularization via the miR-133a-3p/MMP-X1 axis in diabetic retinopathy

Diabetic retinopathy (DR), a most common microangiopathy of diabetes, causes vision loss and even blindness. The mechanisms of exosomal lncRNA remain unclear in the development of DR. Here, we first identifed the pro-angiogenic effect of exosomes derived from vitreous humor of proliferative diabetic retinopathy patients, where lncRNA-MIAT was enriched inside. Secondly, lncRNA-MIAT was demonstrated significantly increased in exosomes from high glucose induced human retinal vascular endothelial cell, and can regulate tube formation, migration and proliferation ability to promote angiogenesis in vitro and in vivo. Mechanistically, the pro-angiogenic effect of lncRNA-MIAT was via the lncRNA-MIAT/miR-133a-3p/MMP-X1 axis. The reduced level of lncRNA-MIAT in this axis mitigated the generation of retinal neovascular in mouse model of oxygen-induced retinopathy (OIR), providing crucial evidence for lncRNA-MIAT as a potential clinical target. These findings enhance our understanding of the role of exosomal lncRNA-MIAT in retinal angiogenesis, and propose a promising therapeutic strategy against diabetic retinopathy.

Referrals for proliferative diabetic retinopathy from two UK diabetic retinopathy screening services: a 10-year analysis of visual outcomes, requirement for vitrectomy, and mortality.

To determine long-term outcomes of patients referred with proliferative diabetic retinopathy (PDR) from diabetic eye screening programmes (DESP) to tertiary care centres in the United Kingdom (UK). Retrospective multicentre study of patients referred from two DESPs in the UK over a 36-month period (2007-9) and followed-up for 10 years. Critical outcomes included severe vision loss (SVL) and the need for vitrectomy. Other outcomes assessed included moderate vision loss (MVL), and patient survival time. Univariate and multiple variable Cox proportional hazards regressions were used to analyse survival outcomes. 212 eyes of 150 patients were referred with a diagnosis of PDR. 109 eyes of 72 patients were confirmed to have active PDR and included in the study. 61% of patients had low-risk PDR, while 39% exhibited high-risk features in at least one eye. Eight (7.3%) eyes developed SVL and 16 (14.7%) MVL during follow up. Vitrectomy was required in 24% (95% CI: 15 to 31%) of all PDR eyes and was most commonly performed for vitreous haemorrhage (65%). The 10-year survival in all PDR patients was 76% (95% CI: 63 to 85%) with the mean time to death for all deceased patients being 5.4 ± 3.6 years. On multivariable analysis, only age was found to have a significant association with the survival of patients with PDR. During the 10 year follow up SVL was uncommon, but MVL occurred in almost one-fifth of the eyes. Approximately 1 in 4 eyes required vitrectomy, highlighting its significance in patient management.

Proteomic study of vitreous in proliferative diabetic retinopathy patients after treatment with aflibercept: a quantitative analysis based on 4D label-free technique.

To identify different metabolites, proteins and related pathways to elucidate the causes of proliferative diabetic retinopathy (PDR) and resistance to anti-vascular endothelial growth factor (VEGF) drugs, and to provide biomarkers for the diagnosis and treatment of PDR. Vitreous specimens from patients with diabetic retinopathy were collected and analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analyses based on 4D label-free technology. Statistically differentially expressed proteins (DEPs), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway representation and protein interactions were analyzed. A total of 12 samples were analyzed. The proteomics results showed that a total of 58 proteins were identified as DEPs, of which 47 proteins were up-regulated and 11 proteins were down-regulated. We found that C1q and tumor necrosis factor related protein 5 (C1QTNF5), Clusterin (CLU), tissue inhibitor of metal protease 1 (TIMP1) and signal regulatory protein alpha (SIRPα) can all be specifically regulated after aflibercept treatment. GO functional analysis showed that some DEPs are related to changes in inflammatory regulatory pathways caused by PDR. In addition, protein-protein interaction (PPI) network evaluation revealed that TIMP1 plays a central role in neural regulation. In addition, CD47/SIRPα may become a key target to resolve anti-VEGF drug resistance in PDR. Proteomic analysis is an approach of choice to explore the molecular mechanisms of PDR. Our data show that multiple proteins are differentially changed in PDR patients after intravitreal injection of aflibercept, among which C1QTNF5, CLU, TIMP1 and SIRPα may become targets for future treatment of PDR and resolution of anti-VEGF resistance.

Bilateral vitrectomy in patients with proliferative diabetic retinopathy-characteristics and surgical outcomes.

Comparing characteristics and outcomes of patients with bilateral proliferative diabetic retinopathy (PDR) undergoing concurrent and sequential vitrectomy. Patients having bilateral vitrectomy were classified into concurrent (requiring bilateral surgery simultaneously) and sequential (indicating vitrectomy in one eye later) groups. Clinical characteristics and outcomes were compared, and correlation between the first and second-operated eyes was analyzed. One hundred eight and 126 eyes were in the concurrent and sequential groups, respectively. The sequential group was older (50 vs. 45years, P = 0.017), had less retinal detachment (54 vs. 77%, P < 0.001), and better visual outcomes (0.79 vs. 1.30,P = 0.021), especially the second-operated eyes. The concurrent group had weaker correlations of disease severity (phi coefficient: 0.36 vs. 0.61) and post-operative visual acuity (r: 0.12 vs. 0.34) between the first- and second-operated eyes than the sequential group. Prior intravitreal injection of anti-vascular endothelial growth factor (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.15-0.86, P = 0.025) predicted better outcomes, while post-operative neovascular glaucoma predicted worse outcomes (OR 6.5, 95%CI 1.7-27.9, P = 0.008). PDR patients requiring surgery concurrently were younger and had more severe diseases and worse outcomes. However, poor outcomes in the first eye did not predict similar outcomes in the second eye.

Loss to Follow up in Patients with Proliferative Diabetic Retinopathy Treated with Anti-VEGF Therapy and/or Panretinal Photocoagulation in the United States

PurposeTo determine the rate of loss to follow up (LTFU) in patients with proliferative diabetic retinopathy (PDR) treated with anti-VEGF therapy and/or PRP in the United States. DesignRetrospective cohort study using the national IRIS® Registry (Intelligent Research in Sight) data. Subjects73,595 eyes of 56,590 patients with PDR diagnosed between 2013-2015 and treated between 2013-2018. MethodsMultivariable logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI). Main Outcome MeasuresLTFU was no follow up within 12 months from last treatment. ResultsFor patient eyes treated for PDR, 11.7% (95% CI, 11.5-12.0) were LTFU. Among PDR patients treated with anti-VEGF therapy alone, PRP alone, and anti-VEGF and PRP, the rates of LTFU were 12.3% (95% CI: 11.8-12.7), 12.6% (95% CI, 12.1-13.0) and 10.8% (95% CI, 10.4-11.1) respectively. Risk factors for LTFU include Black or African American race/ethnicity (OR 1.26; 95% CI, 1.13-1.41; p<0.001), Hispanic ethnicity (OR 1.28; 95% CI, 1.16-1.42; p<0.001), Native American/Alaska Native or Native Hawaiian/Other Pacific Islander race/ethnicity (OR, 2.69; 95% CI, 2.14-3.38; p<0.001), and unilateral disease (OR 2.05; CI, 1.88-2.23; p<0.001). Odds for LTFU were higher with patients with baseline vision of 20/50-20/200 (OR, 1.25; 95% CI, 1.15-1.36; p<0.001) and with vision worse than 20/200 (OR, 1.22; 95% CI, 1.05-1.42; p=0.01) than for patient eyes with a baseline visual acuity of 20/40 or better. Odds for LTFU were lower for Medicare Fee For Service (OR, 0.71; 95% CI, 0.64-0.79; p<0.001) and Medicare Managed (OR, 0.66; 95% CI, 0.56-0.78; p<0.001) compared to Private insurance. Odds for LTFU were lower for patients treated in the Midwest (OR, 0.72; 95% CI, 0.64-0.81; p<0.001) and West (OR, 0.83; 95% CI, 0.74-0.94; p=0.003) compared to in the South region. ConclusionsThe rate of LTFU is between 10-12% among patients with PDR who were treated with anti-VEGF injections and/or PRP. Risk factors include Black or African American race/ethnicity, Hispanic ethnicity, baseline vision worse than 20/40, private insurance, South region and unilateral disease.

The incidence and prevalence of diabetic macular edema and proliferative diabetic retinopathy, their progression to visual impairment and patterns in their intravitreal treatment in the Finnish population.

The worldwide prevalence of diabetes mellitus (DM) continues to increase. As DM is linked to various ophthalmological comorbidities, it is crucial to understand the incidence and the treatment patterns of these complications to minimise the treatment burden for the patient and the healthcare system. This study aims to evaluate the incidence and prevalence of diabetic macular oedema (DME) and proliferative diabetic retinopathy (PDR) and to analyse intravitreal (IVT) treatment patterns and responses in the Finnish population with diabetes. A nationwide data register containing details of over 20-year-old individuals with diabetes was used in the analyses. The incidence and prevalence of DME and PDR among the Finnish population with diabetes either declined or remained stable during 2007-2017 (Incidence rate: DME -40.8%, PDR -65.3%; prevalence rate: DME +4.7%, PDR -11.2%). During the same period, number of persons suffering from diabetes increased by +58.3%. The total number of IVT injections increased by 261.7%; the number of patients receiving IVT treatments increased by 133.6% from 2011 to 2017, reflecting changes in patient numbers in the ophthalmology departments. Furthermore, irrespective of the rising number of patients with diabetes, the numbers with visual impairment declined by 75.8% among DME and by 75.7% among PDR patients in 2007-2017. Regardless of the considerable increase in the workload of ophthalmology departments, the healthcare system has been able to reduce both the age and sex standardised incidence of DME and PDR among the diabetic population suffering from a visual impairment associated with this disease.

Effectiveness and safety of early lens extraction during par plana vitrectomy for proliferative diabetes retinopathy with mild cataract: a randomized clinical trial.

To evaluate the effectiveness and safety of early lens extraction during pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR) compared to those of PPV with subsequent cataract surgery. This multicenter randomized controlled trial was conducted in three Chinese hospitals on patients with PDR, aged >45y, with mild cataracts. The participants were randomly assigned to the combined (PPV combined with simultaneously cataract surgery, i.e., phacovitrectomy) or subsequent (PPV with subsequent cataract surgery 6mo later) group and followed up for 12mo. The primary outcome was the change in best-corrected visual acuity (BCVA) from baseline to 6mo, and the secondary outcomes included complication rates and medical expenses. In total, 129 patients with PDR were recruited and equally randomized (66 and 63 in the combined and subsequent groups respectively). The change in BCVA in the combined group [mean, 36.90 letters; 95% confidence interval (CI), 30.35-43.45] was significantly better (adjusted difference, 16.43; 95%CI, 8.77-24.08; P<0.001) than in the subsequent group (mean, 22.40 letters; 95%CI, 15.55-29.24) 6mo after the PPV, with no significant difference between the two groups at 12mo. The overall surgical risk of two sequential surgeries was significantly higher than that of the combined surgery for neovascular glaucoma (17.65% vs 3.77%, P=0.005). No significant differences were found in the photocoagulation spots, surgical time, and economic expenses between two groups. In the subsequent group, the duration of work incapacity (22.54±9.11d) was significantly longer (P<0.001) than that of the combined group (12.44±6.48d). PDR patients aged over 45y with mild cataract can also benefit from early lens extraction during PPV with gratifying effectiveness, safety and convenience, compared to sequential surgeries.

Investigation of the reasons for delayed presentation in proliferative diabetic retinopathy patients.

To investigate reasons for delayed presentation in patients with proliferative diabetic retinopathy (PDR). A questionnaire was designed to investigate consecutive PDR patients with delayed presentation who visited our center between January 2021 and December 2021. The questionnaire was divided into four sections: knowledge regarding diabetic retinopathy (DR), attitude toward DR treatment, difficulties adhering to follow-up plans, and medical care. The systemic disease status and severity of DR were recorded. Logistic analysis was undertaken to investigate DR treatment refusal and delay factors. A total of 157 patients were included in this study, with an average age of 50.0 ± 11.6 years. The median glycated hemoglobin level (HbA1c) was 7.8% (IQR 2.5%). Among the 157 eyes, most required vitrectomy intervention (144, 91.7%); 17 developed neovascular glaucoma (NVG), while only 13 required additional photocoagulation. Among the 36 patients with undiagnosed DM, the reason for delayed DR presentation was a lack of awareness of DM status among these patients (36 cases, 100.0%). Most of the patients with a known history of DM exhibited inadequate DR knowledge (29, 24.0%), believed their good visual acuity did not require DR screening (98, 81.0%), and had poorly controlled diabetes (113, 93.3%). Factors related to refusing DR treatment were patients with an inability to receive regular diabetes treatment in internal medicine clinics (OR 6.78, 95% CI 1.73-26.59, p = 0.006), patients who could not tolerate discomfort during ophthalmic examination and treatment (OR 15.15, 95% CI 2.70-83.33, p<0.001), and patients who did not have any retinal abnormalities detected and were not informed about the need for regular screening (OR 2.05, 95% CI 1.36-3.09, p<0.001). This study investigated the factors contributing to delayed presentation among patients with PDR. Many individuals in the delayed population were found to have undiagnosed DM. Among patients already aware of their DM status, reasons for delay included insufficient knowledge about DR, negative attitudes toward screening and treatment, and difficulties seeking medical care in real-life situations. Furthermore, there needed to be more improvements in the detection, treatment, and follow-up of DR by internal medicine practitioners and ophthalmologists.

Ferroptosis Contributes to Microvascular Dysfunction in Diabetic Retinopathy

Ferroptosis is a new form of cell death characterized by iron-dependent lipid peroxidation. Whether ferroptosis is involved in retinal microvascular dysfunction under diabetic condition is not known. The expression of ferroptosis related genes in patients with proliferative diabetic retinopathy (PDR) and in diabetic mice was determined with RT-qPCR. Reactive oxygen species (ROS), iron content, lipid peroxidation products, and ferroptosis-associated proteins in the cultured human retinal microvascular endothelial cells (HRMECs) and in the retina of diabetic mice were examined. The association of ferroptosis with the functions of endothelial cells in vitro was evaluated. After administration of ferroptosis specific inhibitor Fer-1, the retinal microvasculature in diabetic mice was assessed. Characteristic change of ferroptosis associated marker including GPX4, FTH1, ACSL4, TFRC and COX2 were detected in the retinal fibrovascular membrane of PDR patients, cultured HRMECs and the retina of diabetic mice. Elevated levels of ROS, lipid peroxidation and iron content were found in the retina of diabetic mice and also in cultured HRMECs. Ferroptosis was found to be associated with HRMECs dysfunction under high glucose condition. Inhibition of ferroptosis with specific inhibitor Fer-1 in diabetic mice significantly reduced the severity of retinal microvasculopathy. Ferroptosis contributes to microvascular dysfunction in diabetic retinopathy, and inhibition of ferroptosis might be a promising strategy for the therapy of early-stage diabetic retinopathy.

Serum and Vitreous Levels of Placenta Growth Factor in Diabetic Retinopathy Patients: Correlation With Disease Severity and Optical Coherence Tomographic Parameters.

Purpose The primary objective of this study was to compare placenta growth factor (PlGF) levels in the serum and vitreous of diabetic retinopathy (DR) patients to non-diabetic controls. Additionally, the study aimed to establish associations between serum and vitreous PlGF concentrations and to examine the correlation between vitreous PlGF in DR patients and morphological parameters. Methods This study included serum and vitreous samples from 38 patients, including 21 patients with DR and 17 non-diabetic controls. The control group included non-diabetic patients with rhegmatogenous retinal detachment with retinal tears secondary to posterior vitreous detachment or trauma. PlGF levels were quantified in vitreous and serum samples using an enzyme-linked immunosorbent assay (ELISA). Optical coherence tomography (OCT) scans from DR patients were evaluated to measure the central retinal thickness (CRT) and macular volume (MV). Results DR patients had significantly higher mean vitreous PlGF levels compared to non-DR patients (70.0±39.2 vs. 46.47±9.7 pg/mL, p-value=0.004). However, no significant increase in mean serum PlGF levels was observed in DR patients (p-value=0.232). Within the DR group, proliferative DR (PDR) patients presented significantly higher vitreous PlGF levels than non-PDR (NPDR) patients (76.5±41.0 vs. 42.5±5.0 pg/mL, p-value=0.009). There was no association between serum and vitreous PlGF levels. The correlation between vitreous PlGF levels and morphological parameters was rsp=0.175, p-value=0.488 for CRT, and rsp=0.288, p-value=0.262 for MV. Conclusion This study emphasizes the important role of PlGF in neovascularization, specifically highlighting its overexpression exclusively in vitreous from PDR patients. The observed increase in PlGF levels may be indicative of disease severity. The lack of correlation between vitreous and serum PlGF levels suggests a potential dissociation between intravitreal and systemic PlGF synthesis. Consequently, targeting PlGF in therapeutic approaches may offer an additional strategy for ocular pathologies with a neovascular component.

Assessment of area and structural irregularity of retinal layers in diabetic retinopathy using machine learning and image processing techniques

Diabetes retinopathy prevention necessitates early detection, monitoring, and treatment. Non-invasive optical coherence tomography (OCT) shows structural changes in the retinal layer. OCT image evaluation necessitates retinal layer segmentation. The ability of our automated retinal layer segmentation to distinguish between normal, non-proliferative (NPDR), and proliferative diabetic retinopathy (PDR) was investigated in this study using quantifiable biomarkers such as retina layer smoothness index (SI) and area (S) in horizontal and vertical OCT images for each zone (fovea, superior, inferior, nasal, and temporal). This research includes 84 eyes from 57 individuals. The study shows a significant difference in the Area (S) of inner nuclear layer (INL) and outer nuclear layer (ONL) in the horizontal foveal zone across the three groups (p < 0.001). In the horizontal scan, there is a significant difference in the smoothness index (SI) of the inner plexiform layer (IPL) and the upper border of the outer plexiform layer (OPL) among three groups (p < 0.05). There is also a significant difference in the area (S) of the OPL in the foveal zone among the three groups (p = 0.003). The area (S) of the INL in the foveal region of horizontal slabs performed best for distinguishing diabetic patients (NPDR and PDR) from normal individuals, with an accuracy of 87.6%. The smoothness index (SI) of IPL in the nasal zone of horizontal foveal slabs was the most accurate at 97.2% in distinguishing PDR from NPDR. The smoothness index of the top border of the OPL in the nasal zone of horizontal slabs was 84.1% accurate in distinguishing NPDR from PDR. Smoothness index of IPL in the temporal zone of horizontal slabs was 89.8% accurate in identifying NPDR from PDR patients. In conclusion, optical coherence tomography can assess the smoothness index and irregularity of the inner and outer plexiform layers, particularly in the nasal and temporal regions of horizontal foveal slabs, to distinguish non-proliferative from proliferative diabetic retinopathy. The evolution of diabetic retinopathy throughout severity levels and its effects on retinal layer irregularity need more study.

Lysyl oxidase-mediated elastin upregulation promotes the proliferation and migration of human retinal endothelial cells.

Proliferative diabetic retinopathy (PDR) is a major cause of irreversible blindness in the working age population. The dysfunction of retinal vascular endothelial cells (RVECs) is the primary cause of PDR. Extracellular matrix (ECM) accumulation promotes intracellular signaling required for RVEC proliferation, migration, survival, and tube morphogenesis. This study aimed to investigate the role of lysyl oxidase (LOX) in the cellular function of RVECs and PDR pathogenesis and to identify the underlying mechanisms. Protein expression was determined with western blot. The interaction between LOX and elastin (ELN) was detected using a co-immunoprecipitation (Co-IP) assay, and the Cell Counting Kit-8 (CCK-8) assay evaluated cell viability. A colony formation assay was employed to assess the proliferation of human RVECs (hRVECs), and a transwell assay to determine their migration ability. Streptozotocin was used to establish PDR in mice in vivo. A histological analysis was conducted using hematoxylin and eosin (H&E) staining. The results showed that LOX was overexpressed in PDR patients. The LOX knockdown suppressed ECM formation and hRVEC proliferation and migration. Additionally, LOX upregulated ELN expression. However, overexpressed ELN promoted hRVEC proliferation and migration. In vivo experiments showed that curcumin-mediated LOX deficiency restored retinal tissue structure. The LOX-knockdown suppressed ECM formation and hRVEC proliferation and migration by inactivating ELN. Therefore, LOX/ELN signaling may be a potential PDR biomarker.

Comparison of Widefield OCT Angiography Features Between Severe Non-Proliferative and Proliferative Diabetic Retinopathy.

There is a high and ever-increasing global prevalence of diabetic retinopathy (DR) and invasive imaging techniques are often required to confirm the presence of proliferative disease. The aim of this study was to explore the images of a rapid and non-invasive technique, widefield optical coherence tomography angiography (OCT-A), to study differences between patients with severe non-proliferative and proliferative DR (PDR). We conducted an observational longitudinal study from November 2022 to March 2023. We recruited 75 patients who were classified into a proliferative group (28 patients) and severe non-proliferative group (47 patients). Classification was done by specialist clinicians who had full access to any multimodal imaging they required to be confident of their diagnosis, including fluorescein angiography. For all patients, we performed single-shot 4 × 4 and 10 × 10mm (widefield) OCT-A imaging and when possible, the multiple images required for mosaic 17.5 × 17.5mm (ultra widefield) OCT-A imaging. We assessed the frequency with which proliferative disease was identifiable solely from these OCT-A images and used custom-built MATLAB software to analyze the images and determine computerized metrics such as density and intensity of vessels, foveal avascular zone, and ischemic areas. On clinically assessing the OCT-A 10 × 10 fields, we were only able to detect new vessels in 25% of known proliferative images. Using ultra-widefield mosaic images, however, we were able to detect new vessels in 100% of PDR patients. The image analysis metrics of 4 × 4 and 10 × 10mm images did not show any significant differences between the two clinical groups. For mosaics, however, there were significant differences in the capillary density in patients with PDR compared to severe non-PDR (9.1% ± 1.9 in the PDR group versus 11.0% ± 1.9 for severe group). We also found with mosaics a significant difference in the metrics of ischemic areas; average area of ischemic zones (253,930.1 ± 108,636 for the proliferative group versus 149,104.2 ± 55,101.8 for the severe group. Our study showed a high sensitivity for detecting PDR using only ultra-widefield mosaic OCT-A imaging, compared to multimodal including fluorescein angiography imaging. It also suggests that image analysis of aspects such as ischemia levels may be useful in identifying higher risk groups as a warning sign for future conversion to neovascularization.

High Vasohibin-2 expression correlated with autophagy in proliferative diabetic retinopathy

Vasohibin-2 (VASH2) is confirmed to be associated with angiogenesis. To investigate the vitreous levels of VASH2 and how VASH2 induces angiogenesis in proliferative diabetic retinopathy (PDR), a total of 120 eyes were enrolled in this prospective and randomized controlled study and the vitreous level of VASH2 was quantified by Luminex liquid suspension chip. Vector systems were applied in human retinal microvascular endothelial cells (HRMECs) for VASH2 gene overexpression, along with interfering lentiviral vectors (VASH2-shRNA) for VASH2 gene silencing. Cell migration, autophagic flux, as well as the expression of α-tubulin, detyrosinated ⍺-tubulin, LC3 II/LC3 I, P62 were detected under normal, VASH2 overexpression, or interference conditions. The level of VASH2 in PDR patients was significantly higher (218.61 ± 30.14 pg/ml) than that in ERM/MH patients (80.78 ± 2.05 pg/ml) (P = 0.001). The migration ability of HRMECs was significantly increased in VASH2 overexpression group, while in the interfering group, the migration ability decreased. VASH2 increased the detyrosination of ⍺-tubulin. The high fluorescence intensity of autophagic flux showed an activation of autophagy in VASH2 overexpression group, which was also confirmed by the increase of LC3 II/LC3 I ratio and the decrease of P62. Collectively, the present study shows in PDR, vitreous level of VASH2 is higher. VASH2 promotes neovascularization by inducing autophagy, suggesting VASH2 could be a new anti-angiogenic drug target for PDR.

Differences in aqueous humor protein profiles in patients with proliferative diabetic retinopathy before and after aflibercept treatment

PurposeTo investigate the changes in aqueous humor (AH) protein profiles before and after intravitreal aflibercept (IVA) treatment in patients with proliferative diabetic retinopathy (PDR).Methods5 PDR patients provided 10 samples of AH before and after IVA treatment (pre-group vs. post-group). Proteins were identified using liquid chromatography-tandem mass spectrometry. Then, bioinformatics was employed to investigate the functional significance of differentially expressed proteins (DEPs) and hub proteins.ResultsA total of 16 DEPs were identified, consisting of 8 downregulated proteins and 8 upregulated proteins. Bioinformatics analysis indicated that the most significantly enriched biological process was “blood coagulation, intrinsic pathway.” The most significantly enriched signaling pathway was “complement and coagulation cascades.” HBB, HPX, VEGFA, and CA1 were identified as hub proteins for IVA treatment.ConclusionsTogether with the downregulation of the intravitreal vascular endothelial growth factor level, IVA may also change the AH protein composition in PDR patients, with DEPs involved in the blood coagulation, intrinsic pathway, complement, and coagulation cascades. IVA treatment may protect against PDR by regulating HBB, HPX, VEGFA, and CA1 expression.

Renal impairment may indicate postoperative low vision in young patients with proliferative diabetic retinopathy undergoing vitrectomy.

To innovatively evaluate the impact of renal impairment in young work age patients with proliferative diabetic retinopathy (PDR) on their visuality after vitrectomy. To find out whether it is possible to better predict the improvement of visual acuity after vitrectomy in working-age people without adding additional preoperative testing. In view of the fact that diabetic retinopathy and diabetic nephropathy are common diabetic complications of microvascular damage, it is considered whether preoperative renal function can be used as this evaluation index. This paper studies the design under this theme. This retrospective study included 306 patients (306 eyes) diagnosed with PDR and undergoing vitrectomy in our hospital from January 2016 to June 2023. Relevant baseline data were collected, including age, history of kidney disease and clinical laboratory test results. According to the International Standard Logarithmic Visual Acuity Checklist, the best corrected visual acuity was tested on the first day of admission and one month after surgery, and the difference between the two was subtracted. A difference >0 was defined as "vision improved". Patients were classified as vision-improved group (n=245) and non-improved group (n=61). The differences in baseline serum urea nitrogen, creatinine, uric acid, Cystatin C, estimated glomerular filtration rate (eGFR) and urine protein distribution between the two groups were statistically analyzed, binary regression analysis was performed for meaningful parameters, and random forest model ranked the characteristics in importance. 1.A higher level of serum cystatin C [1.02(0.80,1.48) mg/L vs 0.86(0.67,1.12) mg/L, P<0.001] and a lower eGFR [82.3(50.33, 115.11) ml/(min/1.73m²) vs 107.69(73.9, 126.01) ml/(min/1.73m²), P=0.002] appeared in the non-(vision-)improved group compared with the vision-improved group. 2. The occurrence of preoperation proteinuria history of nephropathy take a larger proportion in non-improved group. 3. Univariate regression analysis showed history of nephrology (OR=1.887, P=0.028), preoperative serum urea nitrogen (OR=0.939, P=0.043), cystatin C (Cys-C) concentration (OR=0.75, P=0.024), eGFR (OR=1.011, P=0.003) and proteinuria (OR=3.128, P<0.001) were influencing factors to postoperative visual acuity loss in young working age PDR patients. Excluding other confounding factors, preoperative proteinuria is an independent risk factor for postoperative vision improvement in working-age PDR populations (OR=2.722, P=0.009). 4. The accuracy of the prediction random forst model is 0.81. The model appears to be superior in terms of positive prediction. In young work aged PDR patients undergoing vitrectomy, preoperative urine protein can be an independent indicator of postoperative visual loss. Aggressive correction of kidney injury before surgery may help improve postoperative vision in patients with PDR.

Exploring urinary modified nucleosides as biomarkers for diabetic retinopathy: Development and validation of a ultra performance liquid chromatography-tandem mass spectrometry method

The dynamic modification of RNA plays a crucial role in biological regulation and is strongly linked to human disease development and progression. Notably, modified nucleosides in urine have shown promising potential as early diagnostic biomarkers for various conditions. In this study, we developed and validated a rapid, sensitive, and accurate UPLC-MS/MS method for quantifying eight types of modified nucleosides (N1-methyladenosine (m1A), N6-methyladenosine (m6A), 5-methyluridine (m5U), 5-taurinomethyl-2-thiouridine (τm5s2U), 5-methylcytidine (m5C), 2'-O-methylcytidine (Cm), N1-methylguanosine (m1G), and N7-methylguanosine (m7G) in human urine. Using the method, we measured the urinary concentrations of m1A, m6A, m5U, τm5s2U, m5C, Cm, m1G, and m7G in a total of 21 control individuals and 23 patients diagnosed with diabetic retinopathy (DR). Cm levels showed promise as a diagnostic marker for diabetic retinopathy (DR), with a significant value (P < 0.01) and an AUC of 0.735. Other modified nucleosides also exhibited significant differences within specific subpopulations. As non-proliferative diabetic retinopathy (NPDR) signifies the latent early stage of diabetic retinopathy, we developed a multivariate linear model that integrates patients' sex, age, height, and urinary concentration of modified nucleosides which aims to predict and differentiate between healthy individuals, NPDR patients, and proliferative diabetic retinopathy (PDR) patients. Encouragingly, the model achieved satisfactory accuracy rates: healthy (81%), NPDR (75%), and PDR (80%). Our findings provide valuable insights into the development of an early, cost-effective, and noninvasive diagnostic approach for diabetic retinopathy.

A STUDY TO ASSESS CHANGE IN CONTRAST SENSITIVITY AND VISUAL ACUITY IN PROLIFERATIVE DIABETIC RETINOPATHY PATIENTS UNDERGOING ANTI-VEGF TREATMENT AND ROLE OF LOW VISION AID IN SUCH PATIENTS

Objective: The aim of this study was to study the effect of intravitreal anti-vascular endothelial growth factor (VEGF) on the visual acuity (VA) using logMAR charts and the contrast sensitivity (CS) using the pelli-robson chart in patients of advanced diabetic retinopathy. Design: We performed a retrospective study to assess the change in CS and VA in diabetic retinopathy (DR) with or without proliferative DR patients receiving intra-vitreal anti VEGF. Methods: The study was done at our institution where 40 patients of DR were included in the study, 20 cases (20 eyes) and 20 controls (20 eyes). Moreover, it comes under the criteria of low vision and above 18 years of age and VA &gt;6/60. VA and CS were compared before injection and after injection at 14 days, 30 days, and 90 days, respectively. Results: On comparing the mean of CS change before injections and after injections at 14 days (p=0.036), 30 days (p=0.012), and 90 days (p=0.012), respectively, showed a significant association between change in CS change within group but on comparing with control group at 14 days (p=0.195), 30 days (p=0.247), 90 days (p=0.247), respectively, showed no significant association. Another comparison of mean VA before injection and after injection in the case group at 14 days, 30 days, and 90 days, respectively, (p=0.329) remains the same. Which is insignificant but on comparison with the control group (p=0.02) showed a significant association. Conclusion: Whatever VA and CS are achieved with anti-VEGF was completed at 14 days of injection.

Study on Risk Factors Associated with Severity of Diabetic Retinopathy in Type-2 Diabetic Patients, Attending a Tertiary Care Centre in Kerala

Introduction: Diabetic retinopathy (DR) is a significant public health concern affecting individuals with diabetes mellitus (DM). Despite treatment advances, a substantial proportion of patients do not respond adequately. This study investigates risk factors associated with the progression of non-proliferative diabetic retinopathy (NPDR) to proliferative diabetic retinopathy (PDR) in type-2 diabetes patients. Methods: A retrospective case-control study was conducted on diabetic patients older than 40 years with at least 5 years of Type-2 Diabetes Mellitus history, attending ophthalmology clinic in Government Medical College, Thrissur, a tertiary care hospital. Data from patients with retinal examination showing diabetic retinopathy were analyzed. Records with missing data were excluded. Patients with Proliferative Diabetic Retinopathy (n=153) were compared with those having Non- Proliferative Diabetic Retinopathy (n=230). Various risk factors were assessed using statistical analysis. Results: Among the studied variables, sex, duration of diabetes, serum urea, serum creatinine, serum triglycerides, and chronic kidney disease were significantly different between Proliferative Diabetic Retinopathy and Non-Proliferative Diabetic Retinopathy patients. Binary logistic regression revealed that duration of diabetes (OR = 1.8, 95% CI = 1.1 - 2.39) and serum creatinine (OR =1.8, 95% CI = 1.1 - 2.39) independently influenced Proliferative Diabetic Retinopathy development. Conclusion: This study highlights that longer diabetes duration and elevated serum creatinine levels independently increase the risk of Non- Proliferative Diabetic Retinopathy progressing to Proliferative Diabetic Retinopathy in type-2 diabetic patients. Other factors such as age, gender, hyperlipidemia, systemic hypertension, type of diabetic treatment, and history of ischemic heart disease did not show significant associations with disease progression. These findings emphasize the importance of close monitoring, early detection, and intervention in patients with Non- Proliferative Diabetic Retinopathy, particularly those with a longer diabetic history, to prevent Proliferative Diabetic Retinopathy development. Further research should explore the causal relationship between serum creatinine and diabetic retinopathy progression and evaluate the impact of renal disease management on disease outcomes. Keywords: Diabetic Retinopathy, diabetes mellitus (DM), Type-2 Diabetes Mellitus (T2DM).