Development and validation of a simple and practical model for early detection of diabetic macular edema in patients with type 2 diabetes mellitus using easily accessible systemic variables.

OBJECTIVE: Diabetic macular edema (DME) is the leading cause of visual impairment in patients with diabetes mellitus (DM). The goal of early detection has not yet achieved due to a lack of fast and convenient methods. Therefore, we aim to develop and validate a prediction model to identify DME in patients with type 2 diabetes mellitus (T2DM) using easily accessible systemic variables, which can be applied to an ophthalmologist-independent scenario. METHODS: In this four-center, observational study, a total of 1994 T2DM patients who underwent routine diabetic retinopathy screening were enrolled, and their information on ophthalmic and systemic conditions was collected. Forward stepwise multivariable logistic regression was performed to identify risk factors of DME. Machine learning and MLR (multivariable logistic regression) were both used to establish prediction models. The prediction models were trained with 1300 patients and prospectively validated with 104 patients from Guangdong Provincial People's Hospital (GDPH). A total of 175 patients from Zhujiang Hospital (ZJH), 115 patients from the First Affiliated Hospital of Kunming Medical University (FAHKMU), and 100 patients from People's Hospital of JiangMen (PHJM) were used as external validation sets. Area under the receiver operating characteristic curve (AUC), accuracy (ACC), sensitivity, and specificity were used to evaluate the performance in DME prediction. RESULTS: The risk of DME was significantly associated with duration of DM, diastolic blood pressure, hematocrit, glycosylated hemoglobin, and urine albumin-to-creatinine ratio stage. The MLR model using these five risk factors was selected as the final prediction model due to its better performance than the machine learning models using all variables. The AUC, ACC, sensitivity, and specificity were 0.80, 0.69, 0.80, and 0.67 in the internal validation, and 0.82, 0.54, 1.00, and 0.48 in prospective validation, respectively. In external validation, the AUC, ACC, sensitivity and specificity were 0.84, 0.68, 0.90 and 0.60 in ZJH, 0.89, 0.77, 1.00 and 0.72 in FAHKMU, and 0.80, 0.67, 0.75, and 0.65 in PHJM, respectively. CONCLUSION: The MLR model is a simple, rapid, and reliable tool for early detection of DME in individuals with T2DM without the needs of specialized ophthalmologic examinations.

Serum autoantibodies against hexokinase 1 manifest secondary to diabetic macular edema onset.

AIMS: Autoantibodies against hexokinase 1 (HK1) were recently proposed to be associated with diabetic macular edema (DME). We hypothesized that anti-HK1 autoantibodies can be used as DME markers and to predict DME onset. MATERIALS AND METHODS: Serum from patients with 1) DME, 2) diabetes mellitus (DM), 3) allergies or autoimmunities, and 4) control subjects was tested for anti-HK1 and anti-hexokinase 2 (HK2) autoantibodies by immunoblotting. Patients with DM were prospectively followed for up to nine years, and the association of anti-HK1 antibodies with new-onset DME was evaluated. The vitreous humor was also tested for autoantibodies. RESULTS: Among patients with DME, 32 % were positive for anti-HK1 autoantibodies (42 % of those with underlying type 1 DM and 31 % of those with underlying type 2 DM), and 12 % were positive for anti-HK2 autoantibodies, with only partial overlap of these two groups of patients. Anti-HK1 positive were also 7 % of patients with DM, 6 % of patients with allergies and autoimmunities, and 3 % of control subjects. The latter three groups were anti-HK2 negative. Only one of seven patients with DM who were initially anti-HK1 positive developed DME. CONCLUSIONS: Anti-HK1 autoantibodies can be used as DME markers but fail to predict DME onset.

Relationship among Serum Homocysteine, Intercellular Adhesion Molecule-1, Monocyte Chemoattractant Protein-1, and Visual Impairment in Diabetic Macular Edema.

OBJECTIVE: To determine the relationship among serum homocysteine (Hcy), intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1) and visual impairment in patients with diabetic macular edema (DME). STUDY DESIGN: Cross-sectional analytical study. PLACE AND DURATION OF STUDY: Yulin Second Hospital, China, from April 2018 to May 2021. METHODOLOGY: A total of 132 patients with diabetic retinopathy (DR), complicated with DME, were selected as observation group; and 132 patients with simple DR were included in the control group. According to visual examination, patients in observation group were divided into visual disability and non-visual disability. Serum Hcy, ICAM-1, MCP-1, and other indicators were measured. RESULTS: Duration of diabetes, levels of serum Hcy, ICAM-1 and MCP-1 in observation group were higher than those in control group (all p <0.001). Levels of serum Hcy, ICAM-1 and MCP-1 in patients with mild, moderate and severe DME were significantly different (all p <0.001). Levels of serum Hcy, ICAM-1 and MCP-1 in patients with visual disabilities were higher than those in patients with non-visual disabilities (all p <0.001). Levels of serum Hcy, ICAM-1 and MCP-1 in visually disabled patients were higher than those in non-visual disability patients (all p <0.001). CONCLUSION: Levels of serum Hcy, ICAM-1 and MCP-1 in patients with DR complicated with DME were higher than those without visual disability; and levels of Hcy, ICAM-1 and MCP-1 in patients with visual disability were higher than those without visual disability. In patients with DR complicated with DME, increase of these serum markers may play an important role in visual disability. Key Words: Diabetic retinopathy (DR), Diabetic macular edema (DME), Hcy, ICAM-1, MCP-1, Visual impairment.

Correlation between Imaging Morphological Findings and Laboratory Biomarkers in Patients with Diabetic Macular Edema.

PURPOSE: To investigate the potential association between peripheral blood biomarkers and morphological characteristics of retinal imaging in patients with diabetic macular edema (DME). METHODS: Participants in this cross-sectional study were 36 consecutive patients (36 eyes) with treatment-naïve DME, who underwent spectral domain-optical coherence tomography (SD-OCT), fundus photography, and fundus fluorescein angiography (FFA). In addition, peripheral blood samples were taken to evaluate full blood count and biochemical parameters. Correlation between imaging characteristics and laboratory parameters was examined. RESULTS: Eyes with central subfield thickness greater than 405 µm presented significantly higher neutrophils/lymphocytes (p = 0.043) and higher lipoprotein (a) compared to eyes with CST < 405 µm (p = 0.003). Presence of hyperreflective foci on SD-OCT was associated with significantly higher white blood cell count (p = 0.028). Ellipsoid zone disruption was associated with significantly lower hematocrit (p = 0.012), hemoglobin (p = 0.009), and red blood cell count (p = 0.026), as well as with higher lipoprotein (a) (p = 0.015). Macular ischemia on FFA was associated with significantly higher monocytes (p = 0.027) and monocytes/HDL (p = 0.019). No significant associations were found between laboratory parameters and subretinal fluid, intraretinal fluid, exudates, cysts, disorganization of inner retinal layers, epiretinal membrane, and external limiting membrane condition. CONCLUSION: Specific imaging morphological characteristics were found to be associated with laboratory parameters in patients with DME. These findings may shed light on the pathophysiology of DME and its correlation with the development of specific clinical signs.

Plasma amino acids and oxylipins as potential multi-biomarkers for predicting diabetic macular edema.

To investigate the pathophysiologic characteristics of diabetic complications, we identified differences in plasma metabolites in subjects with type 2 diabetes (T2DM) with or without diabetic macular edema (DME) and a disease duration > 15 years. An cohort of older T2DM patients with prolonged disease duration was established, and clinical information and biospecimens were collected following the guidelines of the National Biobank of Korea. DME phenotypes were identified by ophthalmologic specialists. For metabolomics studies, propensity matched case and control samples were selected. To discover multi-biomarkers in plasma, non-targeted metabolite profiling and oxylipin profiling in the discovery cohort were validated in an extended cohort. From metabolomic studies, 5 amino acids (asparagine, aspartic acid, glutamic acid, cysteine, and lysine), 2 organic compounds (citric acid and uric acid) and 4 oxylipins (12-oxoETE, 15-oxoETE, 9-oxoODE, 20-carboxy leukotriene B4) were identified as candidate multi-biomarkers which can guide DME diagnosis among non-DME subjects. Receiver operating characteristic curves revealed high diagnostic value of the combined 5 amino acids and 2 organic compounds (AUC = 0.918), and of the 4 combined oxylipins (AUC = 0.957). Our study suggests that multi-biomarkers may be useful for predicting DME in older T2DM patients.

Assessment of Inflammation Biomarkers in Diabetic Macular Edema Treated with Intravitreal Dexamethasone Implant.

Purpose: To evaluate inflammation biomarkers in diabetic macular edema (DME) treated with intravitreal dexamethasone implant (Ozurdex®). Methods: This retrospective single-center study investigated 64 eyes of 64 patients with DME who were nonresponsive to prior antivascular endothelial growth factor and treated with intravitreal Ozurdex. The neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR), and platelet/lymphocyte ratio were calculated. Visual acuity and optical coherence tomography markers, including hyper-reflective dots and subretinal fluid (SRF), were determined, and central retinal thickness was also evaluated monthly for 3 months. Results: The average age was 64.06 ± 7.81 (48-84) years. The baseline NLR and MLR were significantly higher in patients with better visual outcomes (P = 0.029 and P = 0.048, respectively). Better anatomical outcomes were observed in the presence of SRF (P = 0.027). No significant differences were observed in the rates of the presence of SRF and hyper-reflective points about the better functional outcome (P > 0.05). Conclusions: SRF as an imaging biomarker, and NLR and MLR as blood biomarkers, stand out as markers of inflammation and were found to be associated with better response to Ozurdex implantation in DME.

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

OBJECTIVE: This study investigated changes of plasma cytokines and aimed to build a dynamic nomogram for diabetic macular edema (DME) in type 2 diabetes mellitus (T2DM). METHODS: In a pilot cohort, plasma samples were selected from 9 T2DM patients and 9 DME patients to screen for cytokine differences. The screening cytokines were then validated by enzyme-linked immunoassay in a cohort, which contained 100 DME (DME group) and 100 T2DM patients without DME (T2DM group). A dynamic nomogram for predicting DME was developed, based on the plasma cytokines. RESULTS: In the pilot cohort, 11 plasma cytokines were significantly increased in the DME group. In the validation cohort, platelet-derived growth factor (PDGF)-BB, tissue inhibitors of metalloproteinase (TIMP)-1, angiopoietin (ANG-1), and vascular endothelial cell growth factor receptor (VEGFR)-2 were confirmed to be significantly elevated in the DME group. The dynamic nomogram demonstrated good calibration and discrimination, with an area under the receiver operating characteristic curve (AUC) of 0.88. In the test set, sensitivity, specificity, and AUC were 73.3%, 80.0%, and 0.84, respectively. CONCLUSION: Plasma cytokines were closely associated with DME. A novel dynamic monogram including ANG-1, PDGF-BB, TIMP-1, and VEGFR2 was a novel tool for predicting DME.

Higher levels of circulating ANGPTL2 are associated with macular edema in patients with type 2 diabetes.

ABSTRACT: Macular edema (ME) is an inflammatory disease characterized by increased microvascular permeability. Here, we proposed that plasma angiopoietin-like protein 2 (ANGPTL2) level may be related to the severity of ME patients with type 2 diabetes mellitus (T2DM). In this cross-sectional study, 172 T2DM patients were recruited and divided into clinically significant macular edema (CSME), non-CSME (nCSME), and control groups. Serum ANGPTL2 level was quantified by ELISA and best corrected vision acuity (BCVA) was detected. After adjust age, sex, body mass index (BMI), and duration of diabetes variables, ANGPTL2 performed statistics difference among CSME-, nCSME-groups, and control group (4.46 [3.97, 4.96, 95%CI] ng/mL in CSME group, 3.80 [3.42, 4.18, 95%CI] ng/mL in nCSME-group, 3.33 [3.03, 3.63, 95%CI] ng/mL in control, P < .01). After adjustment of confounding factors, high levels of circulating ANGPTL2 were related with the diagnosis of ME, BCVA, and C reactive protein (CRP) through univariate regression analysis (P < .05). Meanwhile, in the multiple regression model, ANGPTL2 took the mainly effect proportion for the diagnosis of diabetic macular edema (DME), with a LogWorth value 3.559 (P < .001). Our study suggested that elevated circulating ANGPTL2 may be associated with the development of DME and the severity of visual impairment in patients with type 2 diabetes.

Pre-therapeutic Biomarkers for Ranibizumab Therapy among Type 2 Diabetic Patients with Diabetic Macular Edema.

SIGNIFICANCE: A differential outcome in randomized controlled trials of anti-vascular endothelial growth factor (anti-VEGF) therapy, including ranibizumab, for diabetic macular edema is a major dilemma for planning, optimizing, and managing clinical usage. The variable outcome of the therapeutics necessitates the importance of finding a predictive biomarker for anti-VEGF therapy to improve subject selection. PURPOSE: Our study correlates the baseline pro- and anti-VEGF isoforms and its three receptors (VEGFReceptor1, VEGFReceptor2, and VEGFReceptor3) for circulatory candidate protein molecules among diabetic patients with macular edema, with the clinical outcome of ranibizumab therapy. METHODS: This study included 86 individuals who were anti-VEGF naive at the time of ascertainment but have completed the standardized therapy regimen of the clinic. Plasma proteins for pro- and anti-VEGF isoforms and its three receptors were determined in replicate by an enzyme-linked immunosorbent assay. RESULTS: The study demonstrated that 56 (65.12%) individuals benefited from the therapy in terms of letter gain (Snellen chart). Baseline plasma soluble VEGF receptor 2 (sVEGFR-2) was significantly higher among responders (65.10 pg/mL; 95% confidence interval, 55.41 to 74.80 pg/mL) compared with nonresponders (46.38 pg/mL; 95% confidence interval, 38.69 to 54.07 pg/mL; PFDR = .03). Diffuse diabetic macular edema with proliferative diabetic retinopathy increases the risk of nonresponse to the therapy by 3.03-fold (PFDR = .04). CONCLUSIONS: The present study postulates that diffuse diabetic macular edema with proliferative diabetic retinopathy and baseline circulatory soluble VEGF receptor 2 may be potential candidates as therapy-stratifying markers for ranibizumab treatment among patients with diabetic macular edema.

Ischemia-Modified Albumin Levels and Thiol-Disulphide Homeostasis in Diabetic Macular Edema in Patients with Diabetes Mellitus Type 2.

PURPOSE: It was aimed to assess the role of thiol-disulphide homeostasis and ischemia-modified albumin (IMA) level in the development of diabetic macular edema (DME) in patients with diabetes mellitus type 2 (T2DM). MATERIALS AND METHODS: Sixty-six study patients were divided into two groups. Group I included 43 patients with T2DM and DME, and Group 2 included 23 patients with T2DM without eye involvement. A novel colorimetric method was used to assess thiol-disulphide homeostasis. Between the two groups IMA, total anti-oxidant, and total oxidant levels were measured and compared. RESULTS: In Group 1, total and native thiol levels and disulphide levels were lower compared to Group 2 (p = .025, p < .001 and p = .013, respectively). Disulphide/native thiol, disulphide/total thiol ratios and native thiol/total thiol were similar between the groups. Total anti-oxidant level (TAL) reduced whereas total oxidant level (TOL) increased in Group 1 compared to Group 2 (p = .001, p = .002, respectively). Albumin level decreased, whereas IMA level increased in Group 1 compared to Group 2 (p < .001 for both). CONCLUSIONS: The disruption in thiol/disulphide homeostasis, increased IMA and oxidative stress have an impact on the development of diabetic macular edema.

Systemic Regulatory T Cells and IL-6 as Prognostic Factors for Anatomical Improvement of Uveitic Macular Edema.

Purpose: To investigate whether systemic immune mediators and circulating regulatory T cells (Tregs) could be prognostic factors for anatomic outcomes in macular edema secondary to non-infectious uveitis (UME). Methods: Multicenter, prospective, observational, 12-month follow-up study of 60 patients with UME. Macular edema was defined as central subfield thickness (CST) > 300 µm measured with spectral domain optical coherence tomography (SD-OCT). Serum samples and peripheral blood mononuclear cells (PBMC) were obtained from venous blood extraction at baseline. Serum levels of IL-1ß, IL-6, IL-8, IL-17, MCP-1, TNF-α, IL-10, and VEGF were determined by Luminex. Tregs population, defined as CD3+CD4+FoxP3+ in PBMC, was determined by flow cytometry. Main outcome measure was the predictive association between searched mediators and CST sustained improvement, defined as CST < 300 microns or a 20% CST decrease, at 6 months maintained until 12-months compared to baseline levels. Results: Multivariate logistic regression analysis showed an association between CST sustained improvement at 12 months follow-up and IL-6 and Tregs baseline levels. Higher IL-6 levels were associated with less events of UME improvement (OR: 0.67, 95% CI (0.45-1.00), P = 0.042), whereas higher levels of Tregs favored such improvement (OR: 1.25, 95% CI: 1.12-2.56, P = 0.049). Conclusions: Increased levels of Tregs and reduced levels of IL-6 in serum may be prognostic factors of sustained anatomical improvement in UME. These findings could enforce the opportunity to develop more efficient and personalized therapeutic approaches to improve long-term visual prognosis in patients with UME.

Optical Coherence Tomography Biomarkers of the Outer Blood-Retina Barrier in Patients with Diabetic Macular Oedema.

BACKGROUND: Numerous studies confirmed the main role of the inner blood-retinal barrier in the development of Diabetic Macular Oedema (DMO). Lately, the focus of research shifted towards the external retinal barrier with potential involvement in the pathogenesis of DMO. OBJECTIVE: We aim to identify the OCT changes of the external blood-retinal barrier in patients with DMO and to define them as biomarkers with predictive value. Materials and method. We set up retrospectively 3 groups of patients diagnosed with nonproliferative diabetic retinopathy (NPDR) and DMO, proliferative diabetic retinopathy (PDR) and DMO, and controls. We compared the RPE thickness in every quadrant between groups and performed correlations between best-corrected visual acuity (BCVA) and the thickness of the retinal layers. The Social Science Statistics platform was used for statistical tests. RESULTS: The NPDR-DMO group consisted of 18 eyes, the PDR-DMO group consisted of 19 eyes, and the control group included 36 eyes. In the PDR-DMO group, RPE thickness was decreased in almost all quadrants (p < 0.001); in the NPDR-DMO group, only the central minimum and central maximum values of the RPE thickness were significantly different from the control group. We did not find any strong correlation between BCVA and the thickness of the retinal layers. CONCLUSION: The thickness of the RPE layer is an OCT biomarker able to predict the functioning of the outer BRB. Eyes with PDR-DMO exhibited decreased thickness of the RPE layer in almost all quadrants, highlighting the degenerative changes occurring in a hypoxic environment. The thickness of a specific layer could not be identified as a biomarker to correlate significantly with BCVA, most likely because we did not analyze specific morphologic features, such as continuity and reflectivity. The analysis of the RPE thickness could clarify the unexplained decrease of BCVA and predict early the evolution of DR.

The association between intravitreal ranibizumab therapy and serum cytokine concentrations in patients with diabetic macular edema.

Aim: To investigate the association between intravitreal ranibizumab therapy and serum cytokine concentrations in patients with diabetic macular edema (DME). Methods: Twenty-five patients with center-involved DME were recruited prospectively. Serum samples were collected from the patients before and 4 weeks after two ranibizumab injections. The levels of 32 cytokines at these two time points were assessed using a multiplex array assay. Results: Following two ranibizumab injections, there was a statistically significant decrease in the median [interquartile range] levels of Interleukin 1-1beta (IL-1ß) from 5.56 [3.6, 8.75] to 2.33 [1.51, 2.89], Interleukin 13 (IL-13) from 4.30 [1.84, 18.55] to 0.38 [0.38, 0.78], granulocyte-colony stimulating factor (G-CSF) from 64.65 [42.9, 108] to 37.8 [27.3, 46.37], Interferon gamma (IFN-γ) from 241 [103.33, 753.4] to 94.4626 [42.04, 118.58], Interferon gamma-induced protein 10 (IP-10) from 234.68 [144.16, 285.98] to 158.73 [94.71, 198.64], Macrophage Inflammatory Protein-1 alpha (MIP-1α) from 3.65 [2.62, 11.02] to 1.41 [0.94, 1.88], and Tumor necrosis factor- alpha (TNF-α) from 131.09 [100.68,28 240.27] to 45.19 [24.04, 68.55]. There was a statistically significant increase in the levels of Interleukin 9 (IL-9) from 0.76 [0.76, 7.03] to 19.67 [5.36 27.76], Macrophage Inflammatory Protein-1 beta (MIP-1ß) from 0.28 [0.28, 30 0.28] to 6.79 [I3.74, 14.16], Vascular endothelial growth factor (VEGF) from 2.55 [2.55, 2.55] to 25.24 [14.51, 41.73], and soluble vascular endothelial growth factor -1 (sVEGFR-1) from 333.92 [204.99, 440.43] to 500.12 [38.7, 786.91]. A Bonferroni-corrected p value of 0.00156 was considered statistically significant. Conclusions: In patients with DME, intravitreal ranibizumab therapy appears to influence the serum levels of a range of cytokines. After two injections, intravitreal ranibizumab therapy appears to be associated with a significant decrease in inflammatory mediators and a rise in VEGF and sVEGFR1.

Change in cardiac troponin T level after intravitreal anti-vascular endothelial growth factor treatment: Prospective pilot study.

BACKGROUND: Evaluate subclinical myocardial injury associated with intravitreal anti-vascular endothelial growth factor therapy by measuring serum high-sensitivity cardiac troponin T. METHODS: This is a prospective pilot comparative study conducted at American University of Beirut Medical Center, Beirut, Lebanon. In total, 40 consecutive patients were randomized to receive either intravitreal bevacizumab or ranibizumab. Patients received three consecutive monthly injections of the assigned drug, then continued treatment as needed. Systemic concentrations of high-sensitivity cardiac troponin T and vascular endothelial growth factor were obtained at baseline, week 9, and week 24. Primary endpoint measure was change in high-sensitivity cardiac troponin T levels compared to baseline. Secondary endpoint measure was change in systemic vascular endothelial growth factor levels. RESULTS: There was no significant difference in high-sensitivity cardiac troponin T levels over time (p = 0.227) within each treatment group and no significant difference between treatments at any time point (p = 0.276). There was a significant decrease in plasma vascular endothelial growth factor levels at week 9 (p = 0.001) and week 24 (p < 0.001) compared to baseline. In the ranibizumab group, vascular endothelial growth factor levels were not significantly different at weeks 9 and 24 compared to baseline (p = 0.708 and p = 0.117, respectively). There was a significant association between the number of bevacizumab injections from weeks 8 to 24 and the decrease in vascular endothelial growth factor levels at week 24 (R = -0.67, p = 0.032). This correlation was not observed in the ranibizumab group (R = -0.341, p = 0.141). CONCLUSION: Repeated intravitreal bevacizumab or ranibizumab did not influence serum high-sensitivity cardiac troponin levels. Intravitreal bevacizumab but not ranibizumab lowered free-systemic vascular endothelial growth factor levels, which was observed in this study to be inversely related to the number of bevacizumab injections.

Serum pro-inflammatory factors as predictors of persistent diabetic macular oedema with limited anatomic response to anti-VEGF: association with intravitreal injection treatment profiles in real-world setting.

PURPOSE: To study the role of serum levels of pro-inflammatory factors in the identification of persistent diabetic macular oedema (DME) cases with limited anatomic response to anti-VEGF. Additionally, possible predictive associations between serum factors and intravitreal treatment profiles were analysed. METHODS: Cases with DME were treated with monthly bevacizumab (BVZ). After the sixth month of follow-up, if the change in central foveal thickness (CFT) was <20% of baseline, combination treatment with triamcinolone was initiated. All cases underwent a baseline laboratory workup including inflammatory, metabolic and prothrombotic factors. The following outcome parameters were evaluated: percentage of CFT change from baseline, occurrence of persistent DME with <20% change in CFT, achieving CFT <330 µm with ≤6 BVZ injections, total number of intravitreal injections (IVI), number of IVI after the 6th month and number of triamcinolone acetonide (TCA) injections. RESULTS: A total of 58 cases were included receiving a mean of 7.23 ± 1.55 IVI in 12 months, resulting in a significant improvement of visual acuity (VA) and CFT. No significant differences were found for baseline CFT, baseline LogMAR VA, diabetic retinopathy grade, age or duration of DM2 between cases initiating TCA and those treated only with anti-VEGF. Significant correlations were found between total number of IVI and the following serum factors: high-sensitivity C-reactive protein (hsCRP) (p = 0.004, r = 0.395), creatinine (p = 0.023, r = 0.338) and homocysteine (p = 0.037, r = 0.309). Regression analysis revealed that hsCRP was a significant predictor of TCA treatment (p = 0.028, r2  = 0.350). Cases requiring ≤6 IVI had significantly lower values of hsCRP (1.33 ± 1.07 versus 2.46 ± 2.18 mg/l, p = 0.016) and creatinine (0.71 ± 0.28 versus 0.94 ± 0.19 mg/dl, p = 0.003). CONCLUSIONS: Serum markers of microvascular damage (hsCRP, homocysteine and creatinine) were associated with a higher frequency of IVI due to persistent DME, suggesting a role for such biomarkers in the identification of limited responders to anti-VEGF monotherapy.

Evaluation of long-term intravitreal anti-vascular endothelial growth factor injections on renal function in patients with and without diabetic kidney disease.

BACKGROUND: Administering anti-vascular endothelial growth factor (anti-VEGF) by intraocular injection has been shown to have a safe systemic profile. Nevertheless, incidents of acute kidney injury following anti-VEGF injection have been reported. We assessed the long-term effect of multiple intravitreal anti-VEGF injections on measures of renal function in patients with diabetes including rate of change of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (ACR). METHODS: A retrospective review of patients receiving diabetic macular oedema (DMO) treatment was undertaken. Serum creatinine, ACR, number of intravitreal anti-VEGF injections and clinical characteristics were collected from electronic healthcare records (EHR). A co-efficient of eGFR and ACR change with time was calculated over a mean duration of 2.6 years. Regression modelling was used to assess variation in the number of anti-VEGF injections and change in eGFR and ACR. RESULTS: The EHR of 85 patients with DMO (59% male, 78% type 2 diabetes mellitus [T2DM]) were reviewed. On average, 26.8 intravitreal anti-VEGF injections were given per patient over a mean duration of 31 months. No association between increasing number of anti-VEGF injections and rate of eGFR decline (beta = 0.04, 95% confidence intervals [CI]: - 0.02, 0.09; p = 0.22) or ACR change over time (beta = 0.02, CI: - 0.19, 0.23; p = 0.86) was detected, following adjustment for hypertension, cerebrovascular disease, T2DM, and medications taken. CONCLUSION: Our data suggests regular long-term intravitreal VEGF inhibition does not significantly alter the rate of change in eGFR and/or ACR with increasing number of treatment injections.

Angiopoietins in Diabetic Retinopathy: Current Understanding and Therapeutic Potential.

Diabetic retinopathy (DR) is the commonest cause of blindness in the working-age population of the developed world. The molecular pathophysiology of DR is complex, and a complete spatiotemporal model of the disease is still being elucidated. Recently, a role for angiopoietin (Ang) proteins in the pathophysiology of DR has been proposed by several research groups, and several aspects of Ang signalling are being explored as novel therapeutic strategies. Here, we review the role of the Ang proteins in two important forms of DR, diabetic macular oedema and proliferative diabetic retinopathy. The function of the Ang proteins in regulating blood vessel permeability and neovascularisation is discussed, and we also evaluate recent preclinical and clinical studies highlighting the potential benefits of modulating Ang signalling as a treatment for DR.

Expression of vascular infarction-related molecules after anti-vascular endothelium growth factor treatment for diabetic macular edema.

To determine whether an intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) in eyes with diabetic macular edema (DME) affects the vascular infarction-related molecules (VIRMs). Nineteen eyes with DME were treated with 0.5 mg of intravitreal ranibizumab (IVR), and 22 eyes with DME were treated with 2 mg of intravitreal aflibercept (IVA). Blood was collected before, 1 week and 1 month after the injections. Aqueous humor was collected before and 1 month after the injections. The concentration of the VIRMs (cardiac myoglobin, cardiac troponin, intercellular adhesion molecule, monocyte chemotactic protein-1, matrix metalloproteinase-8, placental growth factor [PlGF], tenascin-C, tissue inhibitor of metalloproteinase-1, thrombospondin-2, vascular cell adhesion molecule-1, and VEGF) were determined by the multiplex assay. After the single injection of both types of anti-VEGF agents, the concentration of aqueous VEGF decreased significantly (P < 0.01). The plasma VEGF was reduced significantly at 1 week after the IVA (93.7 ± 17.6 to 39.5 ± 11.6 pg/ml; P < 0.01) but no significant change was seen after IVR (120.2 ± 11.3 to 137.4 ± 17.7 pg/ml). No significant changes were detected for the other VIRMs in the plasma and aqueous. A single intravitreal injection of anti-VEGF for DME does not significantly affect the concentration of several VIRMs.

Overt Proteinuria, Moderately Reduced eGFR and Their Combination Are Predictive of Severe Diabetic Retinopathy or Diabetic Macular Edema in Diabetes.

Purpose: Since the combined effects of proteinuria and a moderately decreased eGFR on incident severe eye complications in patients with diabetes are still largely unknown, these associations were determined in a large historical cohort of Japanese patients with diabetes mellitus. Methods: We evaluated the effects of overt proteinuria (OP) (dipstick 1+ and over) and/or moderately reduced estimated glomerular filtration rate (eGFR) (MG) (baseline eGFR 30.0-54.9 mL/min/1.73 m2) on the incidence of treatment-required diabetic eye diseases (TRDED). We divided 7709 patients into four groups according to the presence or absence of OP and MG: no OP without MG (NP[MG-]), OP without MG (OP[MG-]), no OP with MG (NP[MG+]), and OP with MG (OP[MG+]). Multivariate Cox analyses were performed to calculate hazard ratios (HRs) with 95% confidence intervals for combinations of the presence and/or absence of OP and MG on the risk of developing TRDED. Results: During the median follow-up period of 5.6 years, 168 patients developed TRDED. HRs for OP and MG for incident TRDED were 1.91 (95% confidence interval, 1.27-2.87) and 1.90 (1.11-3.23), respectively. HRs for incident TRDED were 1.73 (1.11-2.69) and 5.57 (2.40-12.94) for OP(MG-) and OP(MG+), respectively, in comparison with NP(MG-). Conclusions: In Japanese patients with diabetes, OP and MG were separately as well as additionally associated with higher risks of TRDED. Results indicate the necessity of the simultaneous assessment of proteinuria and eGFR for appropriate evaluation of risks of severe eye complications in patients with diabetes.

Anti-Hexokinase 1 Antibody as a Novel Serum Biomarker of a Subgroup of Diabetic Macular Edema.

Diabetic retinopathy (DR) induces the breakdown of the blood-retinal barrier and promotes neuroinflammation, although autoimmune responses to sequestered retinal antigens remain poorly understood. In this study, we investigated the autoantibodies for retinal antigens in sera from diabetic macular edema (DME) patients. Screening by immunoblotting demonstrated that IgG from 7 of 10 DME sera samples reacted to an ~102-kDa autoantigen from porcine retinas. Immunoprecipitation with autoantibodies from DME sera and subsequent mass spectrometry enabled us to identify hexokinase 1 as an autoantigen reactive to IgG from DME sera. IgG in 7 of 10 DME sera partially colocalized to hexokinase 1 in the outer plexiform layer of rodent retinas. Quantitative analyses using enzyme-linked immunosorbent assays revealed that the serum titers of this autoantibody were significantly higher in the DME sera than those in the sera from diabetic patients without DME, and 20 (24.1%) of the 83 DME serum samples had higher IgG titers than the cutoff value (mean + 2 standard deviations of the sera from diabetic patients without DR). Multivariate logistic regression analysis confirmed that the higher titer of anti-hexokinase 1 IgG was clinically feasible for the diagnosis of DME. These data identify anti-hexokinase 1 antibody as a serum biomarker of a subset of DME.