Intraocular Vascular Endothelial Growth Factor Research Articles

Witrektomia 23 G z podaniem iniekcji inhibitora czynnika wzrostu śródbłonka naczyniowego u chorego na jaskrę neowaskularną, z całkowitym odwarstwieniem siatkówki, krwotokiem do komory przedniej i komory ciała szklistego oka prawego – opis przypadku

IntroductionNeovascular glaucoma is a serious eye disease characterized by neovascularization of their is and anterior chamber angle. The most important risk factors for the development of neovascular glaucoma include retinal ischemia including that caused by proliferative diabetic retinopathy, central retinal vein occlusion, or retinal detachment.Material and MethodsA 61-year-old man with anterior chamber and vitreous chamber hemorrhage, recurrent total retinal detachment and advanced neovascular glaucoma in the right eye.ResultsVisual acuity recorded as hand motion, intraocular pressure measured by applanation tonometry 16 mmHg. The anterior segment showed massive anterior chamber hemorrhage and iris neovascularization. Ultrasound examination of the right eyeball in the B projection showed multiple diffuse extra echoes consistent with hemorrhage into the vitreous chamber and flat total retinal detachment. The patient was scheduled for anterior chamber washout, 23 G posterior vitrectomy with retinal endolaser, silicone oil endotamponade and injection of ranibizumab into the vitreous chamber of the right eye. During the first follow-up, an improvement in visual acuity to a level of 1/50 using Snellen arrays, stabilization of intraocular pressure to a level of 11 mmHg, and retinal adhesion was achieved.ConclusionsPars plana vitrectomy in patients with anterior chamber and vitreous chamber hemorrhage, retinal detachment and neovascular glaucoma is an effective surgical procedure for restoring useful visual acuity. In addition, ranibizumab injection has a direct effect on reducing the level of intraocular vascular endothelial growth factor and causes regression of neovascularization in the retina, angle and iris.

Potential safety signal of pregnancy loss with vascular endothelial growth factor inhibitor intraocular injection: A disproportionality analysis using the Food and Drug Administration Adverse Event Reporting System.

Objectives: Intraocular administration of vascular endothelial growth factor (VEGF) inhibitors may be associated with pregnancy loss. However, little is known about intraocular anti-VEGF therapy during pregnancy. Here, we conducted a pharmacovigilance study using a spontaneous reporting database to evaluate the relationship between intraocular VEGF inhibitors and pregnancy loss. Methods: We used the JAPIC AERS database which is composed of the Food and Drug Administration Adverse Event Reporting System (FAERS) dataset preprocessed by the Japan Pharmaceutical Information Center (JAPIC) to investigate the VEGF inhibitors ranibizumab, aflibercept, and bevacizumab. Disproportionality analyses were conducted for VEGF inhibitors and pregnancy loss. The lower limit of the 95% confidence interval (CI) of the reporting odds ratio (ROR) > 1 and a minimum of three reported cases of pregnancy loss were the detection criteria used in the current study. Results: In the FAERS, 19 pregnancy loss cases were reported for ranibizumab with an ROR of 4.44 (95% CI: 2.42-8.16), 6 for intraocular bevacizumab with an ROR of 32.25 (95% CI: 3.88-267.9), and 4 for intraocular aflibercept with an ROR of 5.37 (95% CI: 1.34-21.49). All these drugs met the detection criteria. Conclusion: Potential safety signals of pregnancy loss were obtained from intraocular administration of VEGF inhibitors during pregnancy. These signals should be validated using a causal design study.

Aqueous Humor Analyses in Patients with Diabetic Retinopathy Who Had Undergone Panretinal Photocoagulation

Purpose To determine the associations between aqueous humor cytokine levels and the severity of diabetic retinopathy and the prior panretinal photocoagulation (PRP) status of patients with diabetic macular edema (DME). Methods We divided 98 DME patients into those with nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), and PRP patients. We compared the concentrations of interleukin- (IL-) 1β, IL-6, IL-8, IL-10, and IL-17; placental growth factor (PlGF); and vascular endothelial growth factor (VEGF) in the aqueous humors. We subclassified PRP patients by the interval between PRP and aqueous sampling and analyzed the associations between aqueous cytokine levels and this interval. Results The aqueous humor levels of IL-6, IL-8, VEGF, and PlGF were significantly higher in the PDR group than in the NPDR group. The PlGF and VEGF levels in the PDR group were significantly higher than those in the PRP group. On PRP subgroup analyses, patients who had undergone PRP within 6 months prior exhibited higher levels of VEGF, PlGF, and TNF-α than did those who had undergone PRP more than 12 months prior. The TNF-α level of the PRP subgroup treated within 6 months prior was significantly higher than that of the PDR group. Regression analyses showed that the levels of VEGF, PlGF, and TNF-α decreased significantly as the interval between PRP and aqueous sampling became longer. Conclusions PDR patients exhibited higher concentrations of VEGF and certain inflammatory cytokines than did NPDR and PRP patients. In the latter patients, the intraocular VEGF and inflammatory cytokine levels fell gradually over time.

Intraocular Cytokine Changes in Patients with Polypoidal Choroidal Vasculopathy Treated with Ranibizumab

Purpose: To investigate the changes in intraocular cytokines after ranibizumab treatment in patients with polypoidal choroidal vasculopathy (PCV).Methods: This multicenter, prospective study enrolled patients with PCV treated with three monthly ranibizumab followed by a <i>pro re nata</i> regimen for 24 weeks. Best corrected visual acuity, slit lamp examination, fundus photography, and optical coherence tomography were performed every 4 weeks. Aqueous humor was collected to measure intraocular cytokines at baseline, week 8, and the time of recurrence or week 20. The association of changes in intraocular cytokines with visual acuity, central macular thickness, central choroidal thickness, area of abnormal vessels, and polyp closure was assessed.Results: This study included 25 eyes. The mean patient age was 70.3 ± 6.1 years. The vascular endothelial growth factor (VEGF) concentration decreased at week 8, but only interferon (IFN)-γ, tissue inhibitors of matrix metalloproteinases (TIMP)-2, and monocyte chemoattractant protein (MCP)-2 decreased at the time of recurrence. The recurrence interval was positively associated with the baseline epithelial-neutrophil activating peptide (ENA)-78, interleukin (IL)-17, leptin, and transforming growth factor-β1, and baseline central macular thickness was positively correlated with the baseline fibroblast growth factor-4 and IL-10. Thick central choroidal thickness was associated with a low basic fibroblast growth factor and high IFN-γ at baseline. The MCP-3 and Tie-2 levels decreased in two eyes with polyp closure.Conclusions: Ranibizumab significantly reduced intraocular VEGF concentrations and consequently improved PCV. However, the cytokines IFN-γ, TIMP-2, and MCP-2, rather than VEGF, were associated with PCV recurrence. Further studies of intraocular cytokines involved in neovascularization in PCV are needed.

Predictors of anti-VEGF efficacy in chronic central serous chorioretinopathy based on intraocular cytokine levels and pigment epithelium detachment subtypes.

The aim of this study was to compare intraocular cytokines among different types of pigment epithelial detachments (PEDs) in patients with chronic central serous chorioretinopathy (CSC) and to investigate the association of cytokine levels and PED types with response to anti-vascular endothelial growth factor (VEGF) therapy. We included 88 patients with chronic CSC and 30 controls. The anti-VEGF agent conbercept was given intravitreally to chronic CSC patients. Cytokines VEGF, interleukin-6 (IL-6), IL-8, IL-10, interferon-inducible protein-10 and monocyte chemoattractant protein-1 in aqueous humour were measured. Treatment efficacy, cytokine levels, changes in best-corrected visual acuity (BCVA) and optical coherence tomography parameters were assessed at baseline and 1 month after treatment. Patients were divided into three groups: flat irregular PED (FIPED) with choroidal neovascularization (CNV), FIPED without CNV and focal PED. Vascular endothelial growth factor (VEGF) was the only cytokine significantly higher in chronic CSC FIPED patients. There were no significant differences in VEGF between FIPED patients with or without CNV (p = 0.234). At 1 month after conbercept injection, treatment effective rates in FIPED patients with or without CNV were significantly higher than in patients with focal PED (p < 0.05). Best-corrected visual acuity (BCVA) was improved in both FIPED groups (p < 0.05), but not in the focal PED group (p = 0.180). All three groups had significant decreases in central macular thickness (p < 0.05), and PED heights in FIPED patients were reduced (p < 0.05). Patients with FIPED in chronic CSC had elevated intraocular VEGF levels and responded favourably to conbercept. Anti-VEGF treatment may be an option for FIPED CSC patients with or without secondary CNV.

Anti-VEGF Drugs Dynamics: Relevance for Clinical Practice.

Background: A drug and disease assessment model was used to evaluate the impact of different treatment regimens on intravitreal ranibizumab, bevacizumab, aflibercept, and brolucizumab concentrations and the proportion of free vascular endothelial growth factor (VEGF) to total VEGF. Methods: A time-dependent mathematical model using Wolfram Mathematica software was used. The pharmacokinetic and pharmacodynamic data for anti-VEGFs were obtained from published reports. The model simulated drug concentration after single and multiple doses of ranibizumab, bevacizumab, aflibercept, and brolucizumab, and it extrapolated time-dependent intraocular free VEGF proportion values. Various fixed treatment regimens (q4, q8, q10, q12) were simulated and evaluated as candidates for clinical utilization. Results: Our mathematical model shows good correlation between intraocular VEGF proportion values and clinical data. Simulations suggest that each anti-VEGF agent would allow for distinct treatment intervals to keep the proportion of free VEGF under threshold levels. Regimens scheduling q8 ranibizumab, q8 bevacizumab, q12 aflibercept, and q10 brolucizumab administration permit to maintain the proportion of unbound VEGF below 0.001%. Conclusions: Fixed q8 ranibizumab, q8 bevacizumab, q12 aflibercept, or q10 brolucizumab regimens may produce adequate intraocular VEGF inhibition.

Serum and aqueous humor adiponectin levels correlate with diabetic retinopathy development and progression.

PurposeTo compare adiponectin (APN) levels in the serum and aqueous humor (AH) and evaluate their association with the development/progression of diabetic retinopathy (DR).MethodsDiabetic patients with (group 3; n = 59) and without (group 2; n = 39) DR and age- and sex-matched normal subjects (group 1; n = 35) were compared. Duration of diabetes, body mass index, serum HbA1c, vascular endothelial growth factor (VEGF), APN, pentraxin 3 (PTX3), platelet derived growth factor (PDGF), intercellular adhesion molecule-1 (ICAM-1), and APN were measured and analyzed.ResultsOne hundred and thirty-three participants were included. Compared to patients without diabetes, diabetic patients with DR had significantly elevated average serum APN levels (5.99±3.89 μg/ml versus 3.51±1.44 μg/ml, P = 0.002) and average AH APN levels (10.94±11.74 ng/ml versus 3.65±3.33 ng/ml, P<0.001). Serum APN was significantly correlated with AH APN (R = 0.512, P<0.001) and AH VEGF (R = 0.202, P = 0.020). The log serum APN was significantly correlated with intraocular cytokines, including log APN, log VEGF, log ICAM, log leptin, log PTX3, log PDGF, angiopoietin, C-reactive protein, and interleukins (IL)-5 and IL-10 (P<0.001, P = 0.020, P<0.001, P<0.001, P = 0.001, P<0.001, P = 0.008, P = 0.009, P<0.001, and P = 0.046, respectively). Log serum VEGF showed a significant correlation only with log AH VEGF (P = 0.001). Multivariate logistic analysis was performed to evaluate the association of DR progression and cytokine concentrations; log Serum APN and log AH APN showed good correlation with the DR progression in each model.ConclusionsAH APN levels correlated well with DR development and progression. Serum APN could be a better marker for estimating intraocular cytokines, including both intraocular APN and VEGF concentrations in clinical field, than serum VEGF in DR patients.

Vitrectomy and external drainage of subretinal fluid containing high concentration of vascular endothelial growth factor for advanced coats disease

This study investigated the surgical outcomes of Coats disease and the role of external drainage (XD) of subretinal fluid (SRF). The study is a multicenter retrospective interventional case series of 26 consecutive eyes of 26 patients who underwent surgeries for advanced Coats disease with retinal detachment. Main outcomes measured were: 1) comparison of complete SRF resolution with or without XD, and 2) variables that were associated with functional postoperative best-corrected visual acuity (BCVA) defined as BCVA of 0.1 or better, 3) intraocular vascular endothelial growth factor (VEGF) levels. Complete SRF resolution was achieved in all 14 eyes in which XD had been performed and in 75% of 12 eyes in which XD had not been performed (P = .03). Multivariable logistic regression analysis revealed that initial BCVA was the only variable associated with functional postoperative BCVA (odds ratio 3.24, 95% CI 0.93–11.33; P = .04). Markedly elevated VEGF levels were noted in the SRF compared with those in the vitreous humor (49,760 ± 52,990 vs. 707 ± 611 pg/mL, P = .03). XD seems to provide better anatomical success than without XD in the treatment of advanced Coats disease as XD could effectively eliminate substantial amount of VEGF in the SRF.

Changes in choroidal structure following intravitreal aflibercept therapy for retinal vein occlusion

AimsTo examine the choroidal change accompanying retinal vein occlusion (RVO) in detail, we measured changes in choroidal structure after intravitreal aflibercept (IVA) injections for RVO using binarisation of enhanced depth...

Systemic Factors Related to Intraocular Levels of Interleukin-6 and Vascular Endothelial Growth Factor in Diabetic Retinopathy.

This study is for identifying systemic factors correlating with intraocular levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in diabetic retinopathy. Forty-two consecutive patients undergoing pars plana vitrectomy (PPV) for PDR were included in this cross-sectional study. The aqueous humor was sampled just prior to PPV for assay of IL-6 and VEGF. One day before PPV, patient characteristics were recorded and a number of systemic markers were amassed, including fasting and postprandial glucose, homeostasis model assessment- (HOMA-) IR, HOMA-beta, C-peptide, insulin, total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein- (Apo-) A, Apo-B, and lipoprotein A (Lp-A). Relationships between systemic determinants and intraocular cytokine levels were analyzed by regression analysis. Mean levels of IL-6 and VEGF were 15.3 pg/mL (range, 2.4–10124.5 pg/mL) and 21.1 pg/mL (range, 3.2–766.1 pg/mL), respectively. After adjustment for age, gender, duration of diabetes, and BMI, multivariate analysis showed significant association of smoking (p=0.002) and HOMA-IR (p=0.003) with intraocular IL-6 levels, while intraocular VEGF and systemic Lp-A levels correlated significantly (p=0.032). Insulin resistance and smoking status impacted intraocular levels of IL-6, while intraocular VEGF levels were influenced by Lp-A. An appreciation for the relationship between systemic factors and intraocular cytokines may help elucidate the complex pathophysiology of diabetic retinopathy.

Combined Multimodal Analysis of Peripheral Retinal and Macular Circulation in Diabetic Retinopathy (COPRA Study)

To systematically examine the relationships between the microvascular indices that are measured on OCT angiography (OCTA) and the presence and extent of peripheral nonperfusion in persons with diabetic retinopathy. A retrospective cross-sectional study of patients who had varying degrees of diabetic retinopathy. The study sample was recruited from 2 large tertiary referral retina clinics. In total, 82 eyes of 45 patients with varying degrees of diabetic retinopathy were enrolled and analyzed. Relationships between peripheral ischemia measured on fluorescein angiography (FA) and OCTA metrics, including foveal avascular zone (FAZ) and vessel density measurements. A significant decrease in mean signal index in both the superficial and deep plexus and binarized flow index in the superficial plexus were found with increasing duration of diabetes mellitus. OCT and OCTA grading showed increasing central macular thickness and prevalence of microvascular abnormalities in the superficial and deep capillary bed with worse retinopathy as measured on the Diabetic Retinopathy Severity Scale. FAZ area and major axis and minor axis length were strongly associated with diabetic retinopathy severity. On classifying eyes into tertiles of peripheral ischemia measured on FA, significant increases in various FAZ metrics, including FAZ area and minor axis length, were noted. Statistically worsening of FAZ OCTA metrics was only seen between tertiles 2 and 3, indicating a non-linear relationship. The presence of neovascularization of the disc, neovascularization elsewhere, or intraretinal microvascular abnormality was associated with a significant increase in FAZ major axis length in the superficial plexus and a significant decrease in binarized flow index in the deep plexus. OCTA metrics are indicators of the severity of peripheral retinal nonperfusion. However, the central ischemic index did not exhibit a linear relationship with peripheral capillary nonperfusion. Our findings suggest that a rise in intraocular vascular endothelial growth factor as a consequence of mild peripheral capillary nonperfusion may play a compensatory role in maintaining the central macular microcirculation. Further investigations with studies employing longitudinal design will improve our understanding of the relationship between macular microcirculation and peripheral ischemia.

The potential effect of human chorionic gonadotropin on vasoproliferative disorders of the immature retina.

Human chorionic gonadotropin (hCG) is known to be a powerful vascular endothelial growth factor (VEGF)-regulating hormone. It stimulates vascularization of the gravid uterus by upregulating VEGF expression. In the body, hCG activates the same receptor as luteinizing hormone (LH). Like hCG, LH is also strongly proangiogenic. Recently, it has been shown that LH/hCG receptors are present in the retina and that both LH and hCG are found in the eye. In fact, the human eye can synthesize its own hCG. We have previously shown that LH and VEGF are significantly correlated in mammalian eyes, potentially implicating LH-receptor/hCG-receptor activation in intraocular VEGF regulation. Given that elevated VEGF is associated with progression of two vasoproliferative pediatric retinal disorders, retinopathy of prematurity and retinoblastoma, our objective was to determine whether hCG may potentially affect VEGF production and pathologic retinal vascularization in vasoproliferative disorders affecting the immature retina. In this study, we used (a) oxygen-induced retinopathy mouse model (standard model for retinopathy of prematurity) and (b) Y79 retinoblastoma cells (a human cell line derived from immature retinal cells). In the oxygen-induced retinopathy model, number of preretinal nuclei (representing pathologic retinal neovascularization) significantly increases by 57% (P<0.05) in hCG-treated mice. In Y79 cells, VEGF production significantly increases by 37% (P<0.05) in hCG-treated cells. These findings suggest that hCG is potentially able to influence retinal vascularization and VEGF production and thus, the hCG receptor may potentially represent a therapeutic target for vasoproliferative retinal disorders affecting the young eye.

Effect of 0.05% Difluprednate Ophthalmic Emulsion on Proinflammatory Cytokine Levels After Retinal Laser Photocoagulation in Rabbits.

We aimed to evaluate the effect of the topical application of a strong corticosteroid, difluprednate, on the levels of inflammatory and angiogenic cytokine in the vitreous and aqueous humor after laser photocoagulation. Pigmented rabbits were treated with retinal laser photocoagulation and divided into 4 groups, namely control (no additional treatment), topical application of difluprednate 0.05%, betamethasone sodium phosphate 0.1%, and sub-Tenon injection of triamcinolone acetonide (STTA). Samples of vitreous and aqueous humor were collected on posttreatment days 0, 1, 7, and 14. The levels of intraocular vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1) were measured using an immunoassay. Intraocular pressure (IOP) was monitored in each group. VEGF, IL-6, ICAM-1, and MCP-1 were significantly elevated on day 1 and were reduced in both the vitreous and aqueous humor following topical application of difluprednate and STTA. Topical betamethasone reduced their levels in the aqueous humor but not in the vitreous. A significant increase of IOP induced by difluprednate returned to control levels after withdrawal of administration. Although the elevation of IOP was an expected, manageable side effect, topical application of difluprednate was more effective than STTA and betamethasone for reducing inflammatory cytokine levels after laser treatment.

Vitreous Levels of Luteinizing Hormone and VEGF are Strongly Correlated in Healthy Mammalian Eyes

ABSTRACTPurpose/Aim: Luteinizing hormone (LH) is known to function as a key regulator of vascular endothelial growth factor (VEGF) expression in reproductive organs. In recent years, LH has also been detected in human vitreous and LH receptors have been identified in human retina. This study was aimed to investigate a potential correlation between LH and VEGF levels in healthy mammalian eyes to provide supporting evidence of LH’s potential involvement in intraocular VEGF regulation.Methods: 18 bovine and 30 porcine eyes were procured from an abattoir and VEGF and LH levels were measured in the vitreous extracted from these eyes by commercially available bovine & porcine ELISA assay kits. Total protein of the vitreous was measured by using Micro BSA protein assay kit.Results: After total protein normalization, the Pearson Correlation Coefficients (PCC) showed a strong and significant correlation between LH and VEGF levels. (Bovine LH/VEGF PCC: 0.89, p < 0.001; Porcine LH/VEGF PCC: 0.80, p < 0.001). Linear regression analyses, adjusted for gender, showed significant linear relationships between LH and VEGF levels in both bovine and porcine vitreous. (Bovine: t-value = 7.69, p < 0.0001, adjusted r2 = .79; Porcine: t-value = 6.71, p < 0.001, adjusted r2 = .62)Conclusions: We show that VEGF and LH are strongly correlated in healthy, adult mammalian eyes. The robustness of the correlation is shown both by its strength of association and reproducibility in two species. Given that LH is well known to regulate VEGF levels in several tissue types, the LH/VEGF linear relationship in vitreous potentially implicates LH in homeostatic VEGF regulation of the eye. Because we also found that the correlation between LH and VEGF only became manifest when our targeted analytes were normalized by total amount of protein, preclinical and clinical investigators should consider normalizing analytes in vitreous by total protein when assessing potential correlations among them.

Thioredoxin-interacting protein deficiency ameliorates diabetic retinal angiogenesis

Diabetic retinopathy is the leading cause of blindness among working-aged adults around the world. Hyperglycemia and intraocular vascular endothelial growth factor (VEGF) over-accumulation are essential for the progression of diabetic retinopathy, which eventually results in proliferative diabetic retinopathy, characterized by pathologic angiogenesis and impaired vision. Thioredoxin-interacting protein (TXNIP) was highly induced in retinal endothelial cells under diabetic conditions. However, the role of TXNIP in diabetes-associated retinal angiogenesis remains elusive. Here, we investigated whether the absence of TXNIP alters diabetes-associated retinal angiogenesis. Exposure of human retinal microvascular endothelial cells (HRMECs) to moderately high glucose (MHG) promoted cell migration and tube formation, but not proliferation. Knockdown of TXNIP suppressed moderately high glucose (MHG)-induced reactive oxygen species (ROS) generation, migration, tube formation and activation of Akt/mTOR pathway in HRMECs. Moreover, gene silencing of TXNIP inhibited VEGF-induced angiogenic response by blocking VEGFR2 and downstream signal pathway Akt/mTOR activation in HRMECs. Furthermore, TXNIP knockout inhibited VEGF or VEGF and MHG-induced retinal angiogenesis ex vivo compared with wild-type mice. In conclusion, our study demonstrated that TXNIP deficiency inhibited VEGF or/and MHG-induced angiogenic response in HRMECs and mice retinas and suggested TXNIP may be a potential therapy target for treating proliferative diabetic retinopathy.

PERSISTENT OVERPRODUCTION OF INTRAOCULAR VASCULAR ENDOTHELIAL GROWTH FACTOR AS A CAUSE OF LATE VITREOUS HEMORRHAGE AFTER VITRECTOMY FOR PROLIFERATIVE DIABETIC RETINOPATHY.

The purpose of this study was to investigate whether vitreous levels of vascular endothelial growth factor (VEGF) predict late vitreous hemorrhage (VH) after vitrectomy for proliferative diabetic retinopathy, and how VEGF level changes in patients with postoperative late VH. Eighty-five eyes of 68 patients with proliferative diabetic retinopathy who underwent vitrectomy were analyzed retrospectively. Vitreous samples were collected from eyes undergoing primary vitrectomy and from eyes with late VH undergoing second vitrectomy. Vitreous VEGF levels were measured using enzyme-linked immunosorbent assay. The relationship between VEGF level and late VH (>4 weeks) occurring during follow-up as well as clinical findings, and changes in VEGF level in eyes with late VH undergoing second vitrectomy were analyzed. Late VH occurred in 20 (24%) of 85 eyes, and 9 eyes required second vitrectomy. Vitreous levels of VEGF were significantly higher (median: 1,945 pg/mL; P < 0.0001) in eyes with late VH than in those without. Preexisting iris neovascularization (P < 0.0001), hypertension (P = 0.002), and proteinuria (P = 0.040) were also significant risk factors of late VH. Multivariate logistic regression analysis showed that a higher vitreous VEGF level was independently associated with a risk of postoperative late VH in patients with proliferative diabetic retinopathy (odds ratio: 20.8, 95% confidence interval: 2.72-159.47; P = 0.003). Vitreous VEGF level at second vitrectomy in patients with late VH was significantly lower compared with that at primary vitrectomy, but remained elevated (median: 1,610 pg/mL; P = 0.023). In patients with proliferative diabetic retinopathy, high intraocular VEGF level at primary vitrectomy was identified as an independent risk factor of postoperative late VH. Persistent overproduction of intraocular VEGF may be associated with postoperative late VH.

Intraocular Vascular Endothelial Growth Factor Levels in Pachychoroid Neovasculopathy and Neovascular Age-Related Macular Degeneration.

To investigate the difference in intraocular vascular endothelial growth factor (VEGF) concentration between pachychoroid neovasculopathy and neovascular age-related macular degeneration (nAMD) and its associations with responses to three monthly anti-VEGF injections as an initial treatment for the two conditions. This study included nine eyes with treatment-naïve pachychoroid neovasculopathy and 21 eyes with treatment-naïve nAMD. Before the initial intravitreal anti-VEGF injection, aqueous humor samples were collected and the concentration of VEGF was measured using enzyme-linked immunosorbent assay. The concentration was compared between the two conditions, and its associations with responses to anti-VEGF therapy were investigated. The mean VEGF concentration in pachychoroid neovasculopathy was significantly lower than that in nAMD (63.4 ± 17.8 pg/ml and 89.8 ± 45.0 pg/ml, respectively; P = 0.035). The VEGF concentration was associated with the presence or absence of drusen (β = 0.503, P = 0.004). After anti-VEGF therapy, 6 (66.7%) of 9 eyes with pachychoroid neovasculopathy and 17 (81.0%) of 21 eyes with nAMD achieved dry macula (P = 0.640). Dry macula at 3 months and 12 months was significantly associated with a low VEGF concentration in pachychoroid neovasculopathy (P = 0.013 and P = 0.042, respectively), but not in nAMD (P = 0.108 and P = 0.219). The mean VEGF concentration in pachychoroid neovasculopathy was lower than that in nAMD, suggesting that the way in which VEGF is involved in angiogenesis may differ between pachychoroid neovasculopathy and nAMD.

Quantification of the vascular endothelial growth factor with a bioluminescence resonance energy transfer (BRET) based single molecule biosensor

Neovascular pathologies in the eye like age-related macular degeneration (AMD), the diabetic retinopathie (DR), retinopathie of prematurity (ROP) or the retinal vein occlusion (RVO) are caused through a hypoxia induced upregulation of the vascular endothelial growth factor (VEGF). So far a correlation of intraocular VEGF concentrations to the impact of the pathologies is limited because of invasive sampling. Therefore, a minimally invasive, repeatable quantification of VEGF levels in the eye is needed to correlate the stage of VEGF induced pathologies as well as the efficacy of anti-VEGF treatment. Here we describe the development of three variants of enhanced BRET2 (eBRET2) based, single molecule biosensors by fusing a Renilla luciferase mutant with enhanced light output (RLuc8) to the N-terminus and a suitable eBRET2 acceptor fluorophore (GFP2) to the C-terminus of a VEGF binding domain, directly fused or separated with two different peptide linkers for the quantification of VEGF in vitro. The VEGF binding domain consists of a single chain variable fragment (scFv) based on ranibizumab in which the light- and the heavy- F(ab) chains were connected with a peptide linker to generate one open reading frame (orf). All three variants generate measureable eBRET2 ratios by transferring energy from the luciferase donor to the GFP2 acceptor, whereas only the directly fused and the proline variant permit VEGF quantification. The directly fused biosensor variant allows the quantification of VEGF with higher sensitivity, compared to the widely used ELISA systems and a wide dynamic quantification range in vitro. Our system demonstrates not only an additional in vitro application on VEGF quantification but also a promising step towards an applicable biosensor in an implantable device able to quantify VEGF reliably after implantation in vivo.

Variability of disease activity in patients treated with ranibizumab for neovascular age-related macular degeneration

PurposeTo analyze choroidal neovasularization (CNV) activity and recurrence patterns in patients with neovascular age-related macular degeneration (nAMD) treated with ranibizumab, and the correlation with individual intraocular vascular endothelial growth factor (VEGF) suppression time (VST).MethodsPost-hoc analysis of data from a prospective, non-randomized clinical study. Patients with nAMD treated with ranibizumab on a pro re nata regimen. Disease activity was analyzed monthly by spectral-domain optical coherence tomography and correlated with VSTs.ResultsOverall, 73 eyes of 73 patients were included in the study with a mean follow-up of 717 days (range: 412-1239 days). Overall, the mean CNV-activity-free interval was 76.5 days (range: 0-829 days). The individual range of the length of dry intervals was high. A total of 42% of patients had a range of more than 90 days. Overall, 16% of patients showed persistent activity. And 12% stayed dry after the initial ranibizumab treatment. No significant correlation was found between the CNV-recurrence pattern and VST (P=0.12).ConclusionsCNV activity in nAMD is irregular, which is reflected in the range of the duration of dry intervals and late recurrences. The biomarker VST solely seems not to be sufficient to explain recurrence pattern of CNV in all AMD patients.

Clinical correlation to differences in ranibizumab and aflibercept vascular endothelial growth factor suppression times

AimTo determine clinical correlations to intraocular vascular endothelial growth factor A (VEGF-A) suppression times (VSTs) on the treatment of neovascular age-related macular degeneration (nAMD) with ranibizumab (Lucentis) or aflibercept (Eylea).MethodsSeven...