Adiponectin-induced activation of ERK1/2 drives fibrosis in retinal pigment epithelial cells.

Adiponectin (APN), a vasoactive cytokine produced by adipocytes, has emerged as a critical player in retinal diseases. Renowned for its antioxidant, anti-angiogenic, and anti-inflammatory properties, APN levels are closely linked to metabolic disorders, such as insulin resistance, obesity, and diabetic retinopathy (DR). Our previous work demonstrated that APN is similar in efficiency as Avastin in limiting neovascularization in retinal endothelial cells. In this study, we analyzed the effect of APN on retinal epithelial cells to understand its potential impact on eye-related pathologies. Overexpression of APN in ARPE-19 cells predominantly yielded the MMW-APN form, accompanied by increased expression of pro-fibrotic markers and decreased levels of tight junction (TJ) proteins, ZO-1, and Occludin. Further, confocal imaging revealed impaired TJ assembly and the integrity of TJ was also compromised as evidenced by the higher paracellular permeability and lower TEER. Besides, rAPN treatment in ARPE-19 cells as well triggered increased expression of pro-fibrotic markers, pro-MMP2, and enhanced cell migration and proliferation. Mechanistically, these pro-fibrotic effects were mediated by APN-induced phosphorylation of ERK1/2, causing RPE cell transdifferentiation. Furthermore, we identified that MMW-APN was the most prevalent form detected in the vitreous humor of proliferative diabetic retinopathy (PDR) patients, emphasizing the clinical relevance of our findings. Overall, our data suggest that APN, particularly its MMW form, induces epithelial-mesenchymal transition (EMT) and fibrosis in RPE cells, potentially driving the angio-fibrotic shift observed in PDR via ERK1/2 activation.

Ets2 Exacerbates Diabetic Retinopathy by Aggravating the Proliferation of Endothelial Cells and Inflammatory Response.

Proliferative diabetic retinopathy (PDR), the most common type of diabetic retinopathy, is a main cause of visual and impairment blindness. Abnormal neovascularization, endothelial dysfunction, and vascular inflammation are important mechanisms for the development of PDR. Ets2 regulates angiogenesis-related genes and inflammation, however, the effect of Ets2 in PDR procession has not been clarified. Thus, this study is performed to investigate whether Ets2 exerts key functions in PDR. In this study, 10-week-old mice were used for establishing STZ-induced diabetic mice, and Ets2 expression was analyzed in retina tissues. Besides, newborn mice were applied to construct oxygen-induced retinopathy (OIR) models. The Ets2 expression, oxidative stress, and inflammation were detected in retina tissues. We found that Ets2 was highly expressed in retina tissues both in diabetic mice and OIR mice. Oxidative stress and inflammatory processes are two factors contributing to the pathogenesis of PDR. In retinal tissues of OIR mice, Ets2 knockdown inhibited expression of inflammatory mediators VEGFA, IL-6, and IL-8, and biomarkers of oxidative stress MCP-1, VCAM-1, and iNOS. ROS production was also inhibited by silencing Ets2. Ets2 deficiency inhibited endothelial cell proliferation in the retina. Furthermore, Ets2 knockdown contributed to suppressing the expression of angiogenesis-related genes VEGFA, JUNB, MMP-9, Tie2, Ang-2, and EphB4. Our study highlights that Ets2 accelerates PDR procession by promoting the proliferation of endothelial cells, oxidative stress, and inflammation, which provides a novel target against PDR.

Reassessment of arterial versus venous perfusion of diabetic retinal neovascularization using ultrawide-field fluorescein angiography.

PURPOSE: The purpose of this study was to assess whether diabetic NV is perfused by the arterial or the venous circulation. METHODS: This is a retrospective, consecutive case series evaluating patients with proliferative diabetic retinopathy (PDR) imaged with ultrawide-field (UWF) fluorescein angiography (FA). Areas of neovascularization elsewhere (NVE) and neovascularization of the disc (NVD) were assessed. Perfusion was defined as arterial, arteriovenous, or venous if the area of diabetic neovascularization (NV) began to hyperfluoresce either prior, during, or after laminar venous flow, respectively. RESULTS: A total of 180 eyes from 176 patients with 928 NV were identified (830 NVE, 98 NVD). Of those, 5.1% of NVE were classified as arterial and 58.2% of NVD were classified as arterial. The remaining NV were classified as arteriovenous except for a small subset (6.1%) which were indeterminate. None of the NV were classified as venous. Noteworthy examples demonstrated NV that nearly fully perfused prior to any detectable fluorescence within nearby veins as well as clear shunting of blood from a feeding artery to a draining vein. CONCLUSIONS: UWF FA images suggest that some NV is perfused by retinal arteries. This may be useful in devising strategies for early detection and treatment of NV precursors. KEY MESSAGES: What is known • Diabetic retinal neovascularization has long been thought to be perfused by the retinal venous circulation. • Vascular endothelial growth factor has been shown to play key roles in both angiogenesis and arteriogenesis. What is new • Ultrawide-field fluorescein angiography demonstrates that at least some diabetic neovascularization is perfused by the retinal arterial circulation. • This supports the hypothesis that diabetic neovascularization may arise from arterially-perfused intraretinal microvascular abnormalities in the capillary bed.

A neural network model for predicting the effectiveness of treatment in patients with neovascular glaucoma associated with diabetes mellitus.

Introduction: The study hypothesizes that neural networks can be an effective tool for predicting treatment outcomes in patients with diabetic neovascular glaucoma (NVG), considering not only baseline intraocular pressure (IOP) values but also inflammation and intraocular microcirculation indicators. Objective: To investigate the diagnostic significance of inflammation and intraocular blood circulation indicators in a neural network model predicting the effectiveness of transscleral cyclophotocoagulation (TSC CPC) treatment in patients with NVG of diabetic origin. Methods: This retrospective cohort study included 127 patients (127 eyes; aged Me 65.0 years) with painful diabetic NVG and 20 healthy individuals (aged Me 61.5 years) as an immunological control. All patients underwent TSC CPC with a diode laser. Treatment success was defined as achieving an IOP level of ≤ 21 mmHg and maintaining or improving best-corrected visual acuity (BCVA) after 12 months of observation. Preoperative systemic immune-inflammation index (SII = platelets × [neutrophils/lymphocytes]) and systemic inflammation response index (SIRI = neutrophils × [monocytes/lymphocytes]) were calculated. We assessed the values of volumetric pulse blood filling, determined by the rheographic coefficient (RQ, 0/00), using the rheoophthalmography (ROG) method. Multiple regression analysis was used to conclude the significance of treatment efficacy based on initial clinical and laboratory indicators, followed by constructing a prediction model in the neural network. Results: The development of the neural network model identified the most significant "input" parameters: SIRI (100%), RQ (85.7%), and SII (80.7%), which significantly influenced treatment success. The sensitivity of the neural network model was 100%, specificity was 30%, and the percentage of correctly predicted events during testing on the control group was 92.9%. Conclusions: Neural network-based prediction of transscleral cyclophotocoagulation effectiveness for patients with diabetic neovascular glaucoma allows for a sufficiently accurate forecast of treatment success with a probability of 92.9%. We believe the in-time correction of systemic inflammation and intraocular blood circulation can significantly reduce intraocular pressure, preserve visual acuity, and improve the quality of life in patients with diabetic NVG after TSC CPC. Further research is required to support these findings.

Vascular endothelial growth factor/connective tissue growth factor and proteomic analysis of aqueous humor after intravitreal conbercept for proliferative diabetes retinopathy.

AIM: To investigate the role of connective tissue growth factor (CTGF) and vascular endothelial growth factor (VEGF) in the protein profile of the aqueous humor in patients with proliferative diabetic retinopathy (PDR) following intravitreal injection of conbercept. METHODS: This study included 72 PDR patients and 8 cataract patients as controls. PDR patients were divided into 3 groups according to the intervals of 3, 5, and 7d between intravitreal conbercept (IVC, 0.5 mg/0.05 mL) injection and pars plana vitrectomy (PPV) performed. Aqueous humor samples were collected before and after IVC and PPV for VEGF and CTGF levels detected with enzyme-linked immunosorbent assay (ELISA). The differential proteomics of 10 patients who underwent PPV surgery 5d after IVC and 8 normal controls was studied, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on the data, and the protein interaction network of 23 differential proteins was studied. RESULTS: Post-IVC, VEGF levels decreased and CTGF levels increased significantly in aqueous humor, with the CTGF/VEGF ratio rising significantly at all intervals. Liquid chromatography tandem mass spectrometry (LC-MS/MS) identified differentially expressed proteins between pre- and post-IVC samples. GO and KEGG analyses revealed involvement in immune response, stress response, complement and coagulation cascades, ferroptosis, and PPAR signaling pathways. PPI analysis highlighted key proteins like APOA1, C3, and transferrin (TF). ELISA assay confirmed the differential expression of proteins such as HBA1, SERPINA1, COL1A1, and ACTB, with significant changes in the IVC groups. CONCLUSION: The study demonstrates that IVC effectively reduces VEGF levels while increasing CTGF levels, thereby modifying the CTGF/VEGF ratio, and IVC significantly alters the protein profile in the aqueous humor of patients with PDR. Proteomic analysis reveals that these changes are associated with critical biological pathways and protein interactions involved in immune response, stress response, and cellular metabolism.

Diabetic macular edema (DME): dissecting pathogenesis, prognostication, diagnostic modalities along with current and futuristic therapeutic insights.

One of the most common health concerns disturbing people within working years globally is diabetes mellitus (DM). One well-known consequence of DM is vascular damage, which can manifest as macro- and microangiopathy affecting the ocular retina. Therefore, Diabetic macular edema (DME) is a major sight-threatening complication of diabetic retinopathy (DR) worldwide. It is the most prevalent cause of significant vision impairment in diabetic patients. Long-term vision loss can be avoided by following early DME treatment guidelines in everyday life. Hence, there are various therapeutic approaches for DME management. Currently, the first-line treatment for DME is anti-VEGF family drugs, such as ranibizumab, brolucizumab, bevacizumab, and aflibercept. Nevertheless, relapses of the disease, inadequate response, and resistance during anti-VEGF therapy are still seen because of the intricate pathophysiological foundation of the disease. Consequently, there is an excellent requirement for therapeutic approaches to advance and become better at controlling diseases more satisfactorily and require fewer treatments overall. We conducted a thorough literature search in the current review to present a comprehensive overview of the primary data about the current DME therapeutic agents. We also covered the novel advances in DME management and probable future treatments being investigated and developed. This review recommended that Large clinical trials should afford sufficient evidence to support these innovative treatment modalities.

Prevalence and Progression of Diabetic Retinopathy in a Tertiary Care Setting: An Initial Review With Recommended Screening Protocols.

INTRODUCTION: The objective of this study is to evaluate diabetic patients with either normal fundus or non-proliferative diabetic retinopathy (NPDR) changes, examine retinal alterations during follow-up, and propose follow-up guidelines within a tertiary eye care setting. METHODS: A five-year prospective longitudinal study is being conducted at the Diabetic Clinic of Al Ibrahim Eye Hospital/Isra Postgraduate Institute of Ophthalmology, Karachi. Induction for the research took place from October 2021 to March 2022, and a two-year preliminary report is presented here. Newly diagnosed type II diabetic patients with normal fundus or NPDR of any stage, irrespective of age, gender, or glycemic status, who were willing to participate and agreed to follow-ups, were included. Patients with proliferative diabetic retinopathy (PDR), diabetic macular edema (DME), fundus non-visibility, or systemic complications of diabetes were excluded. RESULTS: A total of 251 patients were enrolled, consisting of 80 individuals with a normal fundus and 171 with different stages of NPDR, including mild (N=59), moderate (N=91), and severe (N=21) retinopathy. The incidence of progression from mild to moderate NPDR was noted to be 52.5%, with a median time of 3.5 months. Progression from moderate to severe NPDR occurred in 37.1% of cases, with a median time of 4.5 months. Similarly, DME developed in 5% of patients with mild NPDR over eight months, in 22.2% with moderate NPDR over seven months, and in 37.5% with severe NPDR over 4.4 months. CONCLUSION: This study emphasizes the urgent need to revise diabetic retinopathy (DR) monitoring protocols for our Pakistani (Southeast Asian) population. The rapid progression of NPDR and the high rates of DME development demand more frequent screenings. Current guidelines recommending annual screenings are inadequate. Biannual screenings for patients with a normal fundus or mild NPDR, and quarterly assessments for those with moderate or severe NPDR, are necessary.

Glucagon-Like Peptide-1 Receptor Agonists are Not Associated with an Increased Risk of Progressing to Vision-Threatening Diabetic Retinopathy.

PURPOSE: Glucagon-like peptide-1 receptor agonists (GLP-1RA) are used to treat type 2 diabetes mellitus (DM) by augmenting insulin release and sensitivity. We assessed the overall risk for development of vision-threatening diabetic retinopathy (VTDR), proliferative diabetic retinopathy (PDR), and diabetic macular edema (DME), among GLP-1RA users. METHODS: A retrospective cohort of patients with NPDR newly started on a GLP-1RA from a national insurance claims database was compared to a cohort of patients treated with other oral anti-diabetic agents and matched for age, sex, race, index year, and number of active diabetic medications. Exclusions occurred for < 2 years in the database before diagnosis; prior diagnoses of PDR, DME, vitreous hemorrhage, and/or other retinal vascular diseases; and prior intraocular treatment for VTDR. RESULTS: A total of 6093 users of GLP-1RA were matched to 14,122 controls. In the GLP-1RA cohort, 632 (10.1%), 76 (1.2%), and 544 (8.9%) patients progressed to VTDR, PDR, or DME, respectively. This is compared to 1332 (9.5%) VTDR, 165 (1.2%) PDR, or 1148 (8.1%) DME in the control group. Accounting for underlying DM severity with IPTW, no difference in hazard was seen in the GLP-1RA cohort compared to controls for progression to VTDR (HR = 1.02, 95%CI: 0.92-1.14 p = 0.69), DME (HR = 1.06, 95%CI: 0.95-1.1.9, p = 0.31), or PDR (HR = 0.81, 95%CI: 0.58-1.12, p = 0.20). CONCLUSION: We found no difference in the risk for vision-threatening diabetic retinopathy, nor for its component diseases, DME or PDR, with GLP-1RA use compared to other oral anti-hyperglycemic agents in patients with NPDR.

Comparative Analysis of Pain and Duration in Panretinal Photocoagulation: Navilas Laser versus Conventional Laser in Proliferative Diabetic Retinopathy.

Objectives: To compare the pain perception and treatment duration in patients undergoing panretinal photocoagulation (PRP) for high-risk proliferative diabetic retinopathy (PDR) using Navilas laser versus conventional laser. Methods: A study was conducted involving 40 patients with bilateral high-risk PDR. Each patient underwent PRP with conventional laser in one eye and Navilas laser in the other. Laser parameters, including spot size and pulse duration were standardized. Pain perception was evaluated using Verbal Rating Scale (VRS) and Visual Analogue Scale (VAS). Results: The Navilas and conventional laser groups showed no significant differences in baseline visual acuity, lens status, intraocular pressure, cup-to-disc ratio, or cystoid macular edema. The duration of laser treatment was significantly shorter with Navilas laser group (517.3±48.78 seconds, p<0.001). Pain scores (VAS and VRS) were significantly lower in the Navilas laser group (p<0.001, p=0.002 respectively) than in conventional laser group. There was no correlation between VAS and VRS scores and laser time in both the Navilas and conventional laser groups (p>0.05). Conclusion: Utilizing the Navilas laser for PRP in PDR patients offers advantages over conventional lasers, including reduced pain and expedited procedures. These findings contribute valuable insights for optimizing clinical decisions, potentially enhancing patient compliance and minimizing the risk of visual deterioration in diabetic retinopathy treatment.

Effect of anti-vascular endothelial growth factor on early-stage post-vitrectomy macular edema in patients with proliferative diabetic retinopathy.

PURPOSE: To investigate the effectiveness of anti-vascular endothelial growth factor (VEGF) therapy on post-vitrectomy macular edema (PVME) and determine the risk factors for PVME recovery. METHODS: This retrospective study included 179 eyes of 179 patients who underwent pars plana vitrectomy for proliferative diabetic retinopathy and developed PVME within 3 months after surgery. Eyes were grouped according to postoperative anti-VEGF treatment. RESULTS: Central retinal thickness (CRT) decreased significantly from baseline to 3-month follow-up in groups with (509.9 ± 157.2 µm vs. 401.2 ± 172.1 µm, P < 0.001) or without (406.1 ± 96.1 µm vs. 355.1 ± 126.0 µm, P = 0.008) postoperative anti-VEGF treatment. Best-corrected visual acuity (BCVA) did not differ between the two groups during follow-up. In the group not receiving anti-VEGF therapy, BCVA was significantly improved at 1, 2, and 3 months (P = 0.007, P < 0.001, and P < 0.001, respectively), while in the anti-VEGF group, BCVA was significantly improved at 1 and 3 months (P = 0.03 and P < 0.001). A thicker baseline CRT (ß = 0.44; 95% confidence interval, 0.26-0.61; P < 0.001) was significantly associated with decreasing CRT. CONCLUSION: PVME tends to spontaneously resolve in the early postoperative period. The effect of anti-VEGF therapy in the first 3 months after diagnosis appears to be limited.

Anterior Chamber Flare as a Non-Invasive Assessment of Intraocular Immune Status and Ocular Complications in Proliferative Diabetic Retinopathy.

Proliferative diabetic retinopathy (PDR) is a vision-threatening complication of diabetes mellitus (DM). Anterior chamber (AC) flare and intraocular cytokines are potent biomarkers reflecting the intraocular immune status in PDR. This study aimed to elucidate the complex interrelationship between AC flare and intraocular cytokines in PDR eyes. A retrospective observational study was conducted on 19 PDR eyes of 19 patients with type 2 DM, and on 19 eyes of 19 patients with idiopathic macular hole or epiretinal membrane as controls. AC flare was measured before pars plana vitrectomy (PPV). Aqueous humor (AH) and vitreous fluid (VF) samples were collected at the time of PPV, and the quantities of 27 cytokines in both intraocular fluids were analyzed. In the PDR and control groups, Spearman's rank correlation analysis revealed a positive correlation between AC flare and IL-8 level in both AH and VF. Additionally, IL-8 levels in AH correlated positively with IL-8 levels in VF. In the PDR group, receiver operating characteristic curve analysis identified IL-8 level in AH as a significant predictor for both diabetic macular edema (DME) and vitreous hemorrhage (VH) complications. The cut-off values of IL-8 were established at ≥26.6 pg/mL for DME and ≥7.96 pg/mL for VH. Given the positive correlation between AC flare and AH IL-8 level, the present findings suggest that AC flare value may potentially be a non-invasive biomarker for predicting DME.

Case reports: Intraoperative migratory retinal venous thrombus in proliferative diabetic retinopathy.

Purpose: This study aimed to study the characteristics, possible causes, and clinical implications of intraoperative migratory retinal venous thrombus in proliferative diabetic retinopathy (PDR). Cases: Two middle-aged Chinese patients with diabetes mellitus presented with blurred vision and were diagnosed with PDR and tractional retinal detachment (TRD). An interesting phenomenon was observed during pars plana vitrectomy in both patients. Movement of tiny white thrombi and interruption of blood flow were observed in a branch of the central retinal vein when the vein was pulled at the time of fibrovascular membrane delamination and disappeared with the elimination of retinal traction after finishing the process of delamination. Laboratory studies revealed abnormal erythrocyte sedimentation rate, fibrinogen, D-dimer, international normalized ratio, and IgA anti-ß2-glycoprotein I in one patient and elevated fibrinogen and IgA anticardiolipin in the other. Follow-up examinations at 1 week, 1, 3, and 6 months postoperatively showed good prognosis. Fluorescein fundus angiography at 1 month postoperatively showed neither embolus sign nor prolonged venous filling time in both patients. Discussion: Local blood stasis of the retinal vein persistently dragged by the fibrovascular membrane may result in thrombogenesis, and traction of the retina during the delamination process may lead to the movement of thrombi. On the other hand, endothelial injury and disordered local blood stasis during delamination may also activate the biological coagulation process and instant thrombus formation. As well, antiphospholipid antibodies may also be a risk factor of ocular thrombogenesis. Conclusion: This study provides the first videos recording migratory thrombus in terminal vessels, which indicates that fibrovascular membrane in PDR can lead to thrombogenesis due to dragging and hemostasis of the involved retinal vein. PDR patients with fibrovascular membranes may benefit from early relief of vascular traction through fibrovascular membrane delamination.

Chronic myeloid leukemia diagnosed from the course of diabetic retinopathy.

We report a case of chronic myeloid leukemia (CML), which was diagnosed during the management of proliferative retinopathy (PR) in a patient with type I diabetes mellitus due to the fulminant nature of the PR. This case highlights the importance of vigilance on the part of the ophthalmologist in the diagnosis of co-existing systemic disorders, notably hematological malignancy, which aggravates the posterior segment vasculopathy of the eye and the management of which is crucial for the patient. We also describe a short literature review on the clinical features, mechanism of the posterior segment vasculopathy of the eye, and management of PR co-existing in a patient with CML.

Resolution of choroidal effusion and serous retinal detachment after PASCAL photocoagulation in a patient with diabetic retinopathy.

PURPOSE: To present a rare case of PASCAL photocoagulation-induced choroidal effusion and serous retinal detachment in a patient with diabetic retinopathy. METHODS: A case report. CASE DESCRIPTION: A 68-year-old man with type 2 diabetes mellitus presented with decreased vision in both eyes. His best corrected visual acuity (BCVA) was 0.39 logMAR units in both eyes. The patient underwent panretinal photocoagulation (PRP) in two quadrants of both eyes on the same day according to his fundus fluorescein angiography. Three days after the first session of PRP, the BCVA in his left eye deteriorated by 2.0 logMAR units. Fundoscopic examination detected a significant choroidal effusion in inferonasal quadrant of the left eye. A macular Spectral-Domain Optical Coherence Tomography (SD-OCT) scan showed a large macular serous retinal detachment in the left eye. Topical steroid, topical cycloplegic, and 64 mg oral methylprednisolone were initiated. Two weeks later, his BCVA returned to the level of the first visit with a completely resolved choroidal effusion and no subretinal fluid. CONCLUSION: Considering the inflammatory and destructive mechanism of PRP, the laser operator should use the minimum power necessary to avoid possible chorioretinal complications.

Optical coherence tomography angiography for microaneurysms in anti-vascular endothelial growth factor treated diabetic macular edema.

BACKGROUND: We aimed to evaluate microaneurysms (MAs) after treatment with anti-vascular endothelial growth factor (anti-VEGF) therapy to understand causes of chronic edema and anti-VEGF resistance. METHODS: Patients with non-proliferative diabetic retinopathy, with or without macular edema were recruited. Optical coherence tomography angiography (OCTA) MAs-related parameters were observed, including the maximum diameter of overall dimensions, material presence, and flow signal within the lumen. OCTA parameters also included central macular thickness (CMT), foveal avascular zone, superficial and deep capillary plexuses, and non-flow area measurements on the superficial retinal slab. RESULTS: Overall, 48 eyes from 43 patients were evaluated. CMT differed significantly between the diabetic macular edema (DME ) and non-DME (NDME) groups at 1st, 2nd, 3rd, and 6th months of follow-up (P < 0.001; <0.001; 0.003; <0.001, respectively). A total of 55 and 59 MAs were observed in the DME (mean = 99.40 ± 3.18 µm) and NDME (mean maximum diameter = 74.70 ± 2.86 µm) groups at baseline, respectively (significant between-group difference: P < 0.001). Blood flow signal was measurable for 46 (83.6%) and 34 (59.3%) eyes in the DME and NDME groups, respectively (significant between-group difference: P < 0.001). CONCLUSIONS: Compared to the NDME group, the DME group had larger MAs and a higher blood-flow signal ratio. Following anti-VEGF therapy, changes in the diameter of MAs were observed before changes in CMT thickness.

The causal relationship between immune cells and diabetic retinopathy: a Mendelian randomization study.

Purpose: This article explored the causal relationship between immune cells and diabetic retinopathy (DR) using single nucleotide polymorphisms (SNPs) as an instrumental variable and Mendelian randomization (MR). Methods: Statistical data were collected from a publicly available genome-wide association study (GWAS), and SNPs that were significantly associated with immune cells were used as instrumental variables (IVs). Inverse variance weighted (IVW) and MR-Egger regression were used for MR analysis. A sensitivity analysis was used to test the heterogeneity, horizontal pleiotropy, and stability of the results. Results: We investigated the causal relationship between 731 immune cells and DR risk. All the GWAS data were obtained from European populations and from men and women. The IVW analysis revealed that HLA DR on CD14+ CD16- monocytes, HLA DR on CD14+ monocytes, HLA DR on CD33-HLA DR+, HLA DR on CD33+ HLA DR+ CD14- on CD33+ HLA DR+ CD14dim, and HLA DR on myeloid dendritic cells may increase the risk of DR (P<0.05). HLA DR to CD14-CD16- cells, the monocytic myeloid-derived suppressor cell absolute count, the SSC-A count of CD4+ T cells, and terminally differentiated CD4+ T cells may be protective factors against DR (P<0.05). The sensitivity analysis indicated no heterogeneity or pleiotropy among the selected SNPs. Furthermore, gene annotation of the SNPs revealed significant associations with 10 genes related to the risk of developing PDR and potential connections with 12 other genes related to PDR. Conclusion: Monocytes and T cells may serve as new biomarkers or therapeutic targets, leading to the development of new treatment options for managing DR.

Identification of immune-related endoplasmic reticulum stress genes in proliferative diabetic retinopathy using bioinformatics analysis.

Background: Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes, and understanding its molecular mechanisms is crucial. Endoplasmic reticulum (ER) stress has been implicated in various diseases, including diabetic complications. This study aims to elucidate ER stress-related biomarkers in PDR, providing insights into the underlying molecular pathways. Methods: We analyzed two independent PDR datasets, GSE102485 and GSE60436. The GSE102485 dataset (22 PDR and 3 normal samples) was the primary dataset for comprehensive analyses, including differential expression, functional enrichment, PPI network construction, immune cell infiltration, and drug prediction. The GSE60436 dataset (6 PDR and 3 normal samples) was used for validation. In vitro experiments using human umbilical vein endothelial cells (HUVECs) in a high-glucose environment were conducted to validate key bioinformatics outcomes. Western blotting assessed protein levels of ER stress markers (TRAM1 and TXNIP). Results: Differential expression analysis identified 2451 genes, including 328 ER stress-related genes. Functional analysis revealed enrichment in ER stress-related processes and pathways. Hub genes (BCL2, CCL2, IL-1ß, TLR4, TNF, TP53) were identified, and immune infiltration analysis showed altered immune cell proportions. Validation in GSE60436 and in vitro confirmed ER stress gene dysregulation. Drug prediction suggested potential small molecules targeting ER stress markers. Conclusion: This study provides a comprehensive molecular characterization of ER stress in PDR, highlighting altered biological processes, immune changes, and potential therapeutic targets. The identified hub genes and small molecules offer avenues for further investigation and therapy development, enhancing understanding of PDR pathogenesis and aiding targeted intervention creation.

Non-linear relationship between age and subfoveal choroidal thickness in Chinese patients with proliferative diabetic retinopathy.

BACKGROUND: No study has investigated the change regularity between age and subfoveal choroidal thickness (SFCT) in proliferative diabetic retinopathy (PDR). AIM: To investigate the relationship between the SFCT and age in Chinese patients with PDR. METHODS: This was a cross-sectional retrospective study. The participants were hospitalized individuals with type 2 diabetes who underwent vitrectomy for PDR. Con-tralateral eyes that met the criteria were included in the study. All necessary laboratory tests were performed at the time of admission. Central macular thickness (CMT) and SFCT were two quantitative assessments made using enhanced depth imaging optical coherence tomography. CMT was measured automatically and SFCT was measured manually with digital calipers provided by the Heidelberg Eye Explorer software. RESULTS: The final analysis included a total of 234 individuals with PDR. The average age was 55.60 years old ± 10.03 years old, and 57.69% of the population was male. Univariate analysis revealed a significant negative connection between age and SFCT in patients with PDR [ß = -2.44, 95% confidence interval (95%CI): -3.46 to -1.42; P < 0.0001]. In the fully adjusted model, the correlation between SFCT and age remained steady (ß = -1.68, 95%CI: -2.97 to -0.39; P = 0.0117). Spline smoothing showed that the relationship between SFCT and age in patients with PDR was non-linear, with an inflection point at 54 years of age. CONCLUSION: Our findings suggest that age is a key determinant of choroidal thickness. The non-linear link between SFCT and age in PDR patients should be taken into account.

The Effect of Pan-Retinal Photocoagulation on Central Macular Thickness in a Sample of Iraqi Patients With Proliferative Diabetic Retinopathy.

OBJECTIVE: To evaluate the effect of pan-retinal photocoagulation (PRP) on central macular thickness (CMT) in a sample of Iraqi patients with proliferative diabetic retinopathy (PDR). METHODS: This prospective study was conducted at Ghazi Al-Hariri for Surgical Specialties Hospital, Baghdad, from March 2024 to May 2024. A total of 24 eyes from 18 treatment-naive PDR patients with no previous diabetic macular edema (DME) were enrolled. Each eye received PRP in two sessions, one week apart, using the Nidek GYC 500 laser system. CMT was measured at baseline and four weeks after the second PRP session using the Topcon DRI Triton Plus optical coherence tomography (OCT). Statistical analyses, including paired t-tests and Shapiro-Wilk tests for normality, were performed to evaluate changes in CMT. RESULTS: The mean CMT increased from 258.4 ± 30.7 microns at baseline to 269.9 ± 36.8 microns post PRP, with a mean increase of 11.5 ± 26.3 microns. This increase was statistically significant (p = 0.042). The Shapiro-Wilk test confirmed that the data were approximately normally distributed both before (W = 0.960, p = 0.445) and after (W = 0.931, p = 0.103) PRP treatment. CONCLUSION: PRP significantly increases CMT in PDR patients, although no additional treatment for macular edema was necessary. These findings align with previous studies, suggesting that PRP-induced macular thickening is a common outcome. Further research is recommended to explore long-term effects and potential mitigation strategies.

Liquid Biopsy for Proliferative Diabetic Retinopathy: Single-Cell Transcriptomics of Human Vitreous Reveals Inflammatory T-Cell Signature.

Purpose: Current therapies for proliferative diabetic retinopathy (PDR) do not specifically target VEGF-independent, cell-type-specific processes that lead to vision loss, such as inflammatory pathways. This study aimed to identify targetable cell types and corresponding signaling pathways by elucidating the single-cell landscape of the vitreous of patients with PDR. Design: Case series. Subjects: Vitreous and peripheral blood obtained from 5 adult patients (6 eyes) undergoing pars plana vitrectomy for vision-threatening PDR. Methods: Single-cell RNA sequencing (scRNA-seq) was performed on vitreous cells obtained from diluted cassette washings during vitrectomy from 6 eyes and peripheral blood mononuclear cells (PBMCs, n = 5). Droplet-based scRNA-seq was performed using the Chromium 10x platform to obtain single-cell transcriptomes. Differences in tissue compartments were analyzed with gene ontology enrichment of differentially expressed genes and an unbiased ligand-receptor interaction analysis. Main Outcome Measures: Single-cell transcriptomic profiles of vitreous and peripheral blood. Results: Transcriptomes from 13 675 surgically harvested vitreous cells and 22 636 PBMCs were included. Clustering revealed 4 cell states consistently across all eyes with representative transcripts for T cells (CD2, CD3D, CD3E, and GZMA), B cells (CD79A, IGHM, MS4A1 (CD20), and HLA-DRA), myeloid cells (LYZ, CST3, AIF1, and IFI30), and neutrophils (BASP1, CXCR2, S100A8, and S100A9). Most vitreous cells were T cells (91.6%), unlike the peripheral blood (46.2%), whereas neutrophils in the vitreous were essentially absent. The full repertoire of adaptive T cells including CD4+, CD8+ and T regulatory cells (Treg) and innate immune system effectors (i.e., natural killer T cells) was present in the vitreous. Pathway analysis also demonstrated activation of CD4+ and CD8+ memory T cells and ligand-receptor interactions unique to the vitreous. Conclusions: In the first single-cell transcriptomic characterization of human vitreous in a disease state, we show PDR vitreous is primarily composed of T cells, a critical component of adaptive immunity, with activity and proportions distinct from T cells within the peripheral blood, and neutrophils are essentially absent. These results demonstrate the feasibility of liquid vitreous biopsies via collection of otherwise discarded, diluted cassette washings during vitrectomy to gain mechanistic and therapeutic insights into human vitreoretinal disease. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.