Vascular Endothelial Growth Factor In Aqueous Humor Research Articles

Oxidative Stress Participates in Age-Related Cataract Formation by Disrupting Connection between Lens Epithelial Cells through c-Src/VEGF Pathway

Purpose To observe the effects of oxidative stress on vascular endothelial growth factor (VEGF) and connections of lens epithelial cells. Methods Human lens epithelium of patients with age-related cataract (ARC), both SRA01/04 cells and whole mice lens stimulated by H2O2 were employed. VEGF in human aqueous humor of ARC-patients and the supernatant of SRA01/04 cells was determined by ELISA. The expressions of VEFG in human lens epithelium were detected by immunofluorescence staining. Multiple linear regression analysis and spearman rank-order correlation were used to determine the associations between VEGF and parameters of ARC individuals. In H2O2-induced SRA01/04 cells, Catalase (CAT), PP1 (inhibitor of c-Src kinase) and Avastin (VEGF antibody) were used to inhibit the effects of H2O2, activation of c-Src kinase and VEGF, which were detected by Western blot. The alterations of ZO-1 and N-cadherin were tested by immunofluorescence staining and Western blot. In H2O2-induced whole lens, the changes of opacification area in different treatment of inhibitors were observed. Results The secretion of VEGF in aqueous humor and expression of VEGF in the lens epithelium of ARC patients increased significantly with age. In H2O2-induced SRA01/04 cells, the VEGF in the supernatant was increased with the culture duration and the dose of H2O2. The expressions of p-Src418 and VEGF were also up-regulated, whereas the expressions of ZO-1 and N-cadherin were down-regulated. CAT effectively prevented these changes induced by H2O2, while PP1 inhibited not only p-Src418 but also up-regulation of VEGF, Avastin partially inhibited VEGF up-regulation. Both PP1 and Avastin prevented down-regulation of ZO-1 and N-cadherin, respectively, but Avastin combined with PP1 had no significant synergistic effects. In H2O2-induced cataract, CAT prevented development of opacification area effectively, and PP1 and Avastin did partially. Conclusions Oxidative stress disrupts connections of lens epithelial cells by activating c-Src/VEGF, inhibiting which may prevent cataract.

Aqueous humor analyses of diabetic macular edema patients with subretinal fluid

We identified treatment-naïve diabetic macular edema (DME) patients with or without subretinal fluid (SRF). We compared their baseline characteristics: aqueous concentrations of interleukin (IL)-1β, IL-2, IL-6, IL-8, IL-10, and IL-17, as well as tumor necrosis factor-α, vascular endothelial growth factor (VEGF), and placental growth factor (PlGF). We also compared fundus and optical coherence tomography (OCT) findings, and responsiveness to anti-VEGF treatments. Of 67 DME patients, 18 (26.87%) had SRF. Compared to the no SRF group, the SRF group had significantly higher levels of IL-6, IL-8, VEGF, and PlGF in aqueous humor. After grouping according to diabetic retinopathy stage, non-proliferative diabetic retinopathy (NPDR) patients with SRF had higher aqueous levels of IL-6 and IL-8, compared to NPDR patients without SRF. Moreover, proliferative diabetic retinopathy (PDR) patients with SRF had higher aqueous levels of VEGF and PlGF, compared to PDR patients without SRF. Fundus and OCT analyses revealed that the SRF group had a greater proportion of patients with succinate or patch-shaped hard exudates involving the macula, and greater central subfield thickness (CST) at baseline. After 6 months of anti-VEGF treatments, the SRF group showed better responsiveness in terms of CST; however, visual acuity was not correlated with responsiveness. Considering higher aqueous levels of VEGFs and pro-inflammatory cytokines, SRF could be a biomarker related to diabetic retinopathy activity. DME patients with SRF showed better anatomical responsiveness to anti-VEGF treatments, but did not show better functional improvement on short-term evaluation compared to those of DME patients without SRF.

Comparison of Inflammatory and Angiogenic Factors in the Aqueous Humor of Vitrectomized and Non-Vitrectomized Eyes in Diabetic Macular Edema Patients.

Objectives: To compare the aqueous concentrations of inflammatory and angiogenetic factors in vitrectomized vs. non-vitrectomized eyes with diabetic macular edema (DME).Methods: Aqueous samples were obtained from 107 eyes with DME before intravitreal injection of anti-VEGF, 36 eyes with previous pars plana vitrectomy (PPV) combined with pan-retinal endolaser photocoagulation (PRP), and 71 treatment-naïve. Interleukin (IL)-6, IL-8, interferon-induced protein (IP)-10, monocyte chemoattractant protein (MCP)-1, and vascular endothelial growth factor (VEGF) were measured by cytometric bead array (CBA). Optical coherence tomography (OCT) was used for measuring central retinal thickness (CRT).Results: IL-6, IL-8, IP-10, and MCP-1 in aqueous humor of DME vitrectomized eyes were significantly higher than in non-vitrectomized DME eyes, while VEGF was lower than in non-vitrectomized DME eyes. VEGF in aqueous humor significantly correlated with CRT for DME in non-vitrectomized DME eyes. IL-6, IL-8, IP-10, and MCP-1 in aqueous humor were not significantly associated with VEGF for DME in vitrectomized eyes.Conclusions: Inflammation might play an important role in the pathogenesis of DME in vitrectomized eyes. Moreover, inflammation might play a central role in the development of DME via the VEGF-independent pathway. Thus, anti-inflammatory therapy might be a strategy for DME in vitrectomized eyes.

Relationships among Retinal Nonperfusion, Neovascularization, and Vascular Endothelial Growth Factor Levels in Quiescent Proliferative Diabetic Retinopathy.

Purpose: To investigate the relationships among the retinal nonperfusion (NP) area, neovascularization (NV) area, and aqueous humor vascular endothelial growth factor (VEGF) levels in quiescent proliferative diabetic retinopathy (PDR). Methods: Forty-seven eyes from 47 patients with treatment-naïve PDR that did not show macular edema or vitreous hemorrhage were enrolled. NP area, NV number, and NV area were quantitatively measured using ultra-widefield fluorescein angiography in an automated manner. Aqueous humor VEGF level was measured using a bead assay. Results: The NP areas of the total, posterior pole, peripheral retinae, and NV area positively correlated with each other (all p < 0.034). NV number correlated with total NP area, peripheral NP area, and NV area (all p ≤ 0.001). VEGF levels were significantly positively correlated with total, posterior polar, and peripheral NP areas and NV area (r = 0.575, 0.422, 0.558, and 0.362, respectively; all p ≤ 0.012). In eyes with NV in the disc area, the VEGF level was higher compare to eyes without NV in the disc area (208.89 ± 192.77 pg/mL vs. 103.34 ± 132.66, p = 0.010). A multiple linear regression model using NP area, NV area, and NVD demonstrated good prediction for VEGF level (R2 = 0.417, p < 0.001) and revealed a significant contribution of the peripheral NP area in predicting the VEGF level (β = 0.497, p = 0.002). Conclusions: Aqueous humor VEGF levels in quiescent PDR eyes were associated with NP and NV areas, which had positive correlations with each other. In addition, the NP area of the peripheral retina was the most important predictor of VEGF level.

Inflammatory cytokines in highly myopic eyes

Currently, myopic retinopathy is the most common irreversible blinding disease but its pathophysiology is not completely clear. A cross-sectional, observational study was conducted in a single center to analyze aqueous samples from highly myopic eyes (axial length >25 mm, n = 92) and ametropic or mild myopic eyes (n = 88) for inflammatory cytokines. Vascular endothelial growth factor (VEGF), Interleukin 6 (IL-6), and matrix metalloproteinase-2 (MMP-2) were measured using an enzyme-linked immunosorbent assay. IL-6 and MMP-2 were significantly higher in the highly myopic eyes than in the non-high myopic eyes (IL-6: 11.90 vs. 4.38 pg/mL, p < 0.0001; MMP-2: 13.10 vs. 8.82 ng/mL, p = 0.0003) while adjusting for age, gender, and intraocular pressure. There was a significant positive association between levels of IL-6 and MMP-2 in aqueous humor and the axial lengths of the eye globes (IL-6, β = 0.065, p < 0.0001, n = 134; MMP-2, β = 0.097, p < 0.0001, n = 131). Conversely, VEGF in aqueous humor was significantly lower in the highly myopic eyes than in the non-high myopic eyes (45.56 vs. 96.90 pg/mL, p < 0.0001, n = 153) while age, gender, and intraocular pressure were adjusted. The results suggest that low-grade intraocular inflammation may play an important role in the development and progression of high myopia and myopic retinopathy.

Effect of ranibizumab on levels of IL-6 and VEGF in peripheral blood and aqueous humor of glaucoma rat model and association of IL-6 and VEGF with optic nerve damage.

This study aims to investigate the effect of intravitreal injection of ranibizumab on glaucoma rat model and its effect on optic nerve injury. A total of 125 SD rats were used to establish glaucoma models. Of them, 80 well-established model were selected, 40 of which received intravitreal injections of ranibizumab and were assigned to the observation group. The remaining 40 received no drug and were assigned to the control group. After rats were sacrificed at the time-points, the retina was harvested. Numbers of retinal ganglion cells (RGCs) were counted under a fluorescence microscope. In the meantime, levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in peripheral blood and aqueous humor were determined. The levels of IL-6 and VEGF in peripheral blood and aqueous humor decreased gradually over the time of treatment in the observation group (P<0.05). In the control group the levels of IL-6 in peripheral blood and aqueous humor increased gradually over time (P<0.05). At the same time-point, the IL-6 level was higher in the control group than that in the observation group (P<0.05). The VEGF level in the observation group was lower in day 21 than that in day 7 (P<0.05). The VEGF level was higher in the control group than that in the observation group (P<0.05). The number of RGCs in the observation group increased gradually over the time of treatment, and there were significant differences in the number of RGCs between day 7 and 14, as well as day 14 and 21 (P<0.05). The number of RGCs in the control group decreased gradually over time (P<0.05). The levels of IL-6 and VEGF were all negatively correlated with the number of RGCs, and the correlation coefficient r and P-value were −0.743 and 0.012, and −0.675 and 0.022, respectively. Ranibizumab attenuated optic nerve injury by reducing levels of IL-6 and VEGF in peripheral blood and aqueous humor of glaucoma rat model.

Evaluation of Serum and Aqueous Humor Vascular Endothelial Growth Factor in Neovascular Glaucoma

Purpose: The study aimed to evaluate and correlate between the levels of vascular endothelial growth factor (VEGF) in serum and aqueous humor in cases of neovascular glaucoma (NVG) to stand up on if it can be used as a marker for early detection of such cases. Methods: This observational case control study included 60 eyes, divided into 3 groups, group A of 30 eyes presented by cataract of different causes (not diabetic patients and no signs of NVG) as a control group and group B of 30 eyes with NVG due to different causes, group C of the same eyes in group B but after one month of treatment by intravitreal bevacizumab and laser treatment by pan retinal photocoagulation (PRP). Serum VEGF was estimated in all groups, also aqueous humor VEGF was estimated in group A and B only. In addition glycosylated hemoglobin (HbA1c) was estimated in group B; statistical analysis of the results was performed. Results: The study revealed that the commonest cause of NVG was proliferative diabetic retinopathy (PDR) in 26 cases (86.7%), HbA1c in group B revealed mean value 7.68% ± 2.75%. Serum VEFG level in the group B of cases of NVG was significantly higher than the control group A (P 0.05). Conclusions: VEGF is considered a good marker for the NVG either in serum or aqueous humor, laser treatment and the use of anti-VEGF are crucial treatment for such cases, and also glycemic control is a must for regulation of the vascular process in diabetic patients for prevention of such ocular neovascularization.

Efficacy and mechanism of rabbit corneal stromal cell-induced adipose-derived mesenchymal stem cell amnion transplantation for corneal alkali burn

Background Corneal chemical burn is one of blinding eye diseases.Previous therapies for corneal chemical burn is limited to certain extent.However, transplantation of adipose-derived mesenchymal stem cells (ADSCs) for corneal diseases is drawing more and more attention. Objective This study was to observe the effect of rabbit ADSCs transplantation for ocular alkali burns and explore its mechanism. Methods Rabbit corneal stromal cells (CSCs) were isolated and cultured by suspended matrix method, and rabbit ADSCs were obtained and digested from inguinal fat tissue with enzyme digestion method (0.25% trypsin) and identified by flow cytometry.CSCs cocultured with ADSCs, and CSCs-induced ADSCs were identified by double-label of with immunofluorescence and reverse transcription PCR (RT-PCR). Then induced or uninduced ADSCs were inoculated on amniotic membrane to prepared ADSCs-amnion patch.Corneal alkali burn models were established in the right eyes of 60 New Zealand rabbits by placing a filter paper with 1% NaOH solution at the central cornea for 50 seconds.The models were randomized into the induced ADSCs+ amnion implanted group, the uninduced ADSCs+ amnion implanting group, amnion implanted group and model group.Corneal opacification and neovascular area were examined and corneal inflammation was graded by slit lamp microscope 1 week, 2 weeks and 1 month after surgery.The contents of CD45, interferon-γ (IFN-γ) and interleukin-10 (IL-10) in corneal homogenate as well as vascular endothelial growth factor (VEGF) in aqueous humor were detected by ELISA assay.The use and care of experiment animals followed the Statement of ARVO. Results ADSCs showed the positive responses for CD105, CD29, CD44 with the positive rate 90.23%, 88.56% and 98.88%, respectively.CSCs was positively reactive for vimentin.The double-label staining was positive after coculture of CSCs with ADSCs.Hematoxylin-eosin stain exhibited that ADSCs grew well on the amnion.Corneal porcelain opacity and a lot of new blood vessels were seen in the model group, and corneal was clear in the induced ADSCs+ amnion implanted group 1 month after surgery.The inflammatory scores were 1.65±0.18, 2.05±0.17, 2.68±0.25, 2.90±0.18, and the areas of neovasculization were (10.59±1.78), (22.58±1.63), (37.98±1.90), (45.37±1.65)mm2 respectively in the induced ADSCs+ amnion implanted group, uninduced ADSCs+ amnion implanted group, amnion implanted group and the model group.The inflammatory scores of 1 week, 2 weeks, 1 month after operation among the four groups had statistically significant differences（F=280.826, 330.172, 465.707, all at P=0.000), and the areas of neovasculization of 1 week, 2 weeks, 1 month after operation among the four groups had statistically significant differences（F=60.020, 670.811, 1 510.231, all at P=0.000), the inflammatory scores in the induced ADSCs+ amnion implanted group were remarkably lower than those of the other groups, the areas of neovasculization in the induced ADSCs+ amnion inplanted group were smaller than those of the other groups (all at P<0.01). In 1 month after surgery, the contents of CD45, IL-10, IFN-γ in cornea and VEGF in aqueous humor were statistically different among the groups（F=916.545, 1 739.358, 462.134, 129.126, all at P=0.000). Compared with the uninduced ADSCs+ amnion implanted group, amnion implanted group and the model group, CD45 and IFN-γ contents were declined, and IL-10 content was elavated in the induced ADSCs+ amnion implanted group (all at P<0.01). In addition, VEGF contents in aqueous humor were significantly lower than those in the other groups (all at P<0.01). Conclusions Rabbit CSCs-induced ADSCs amnion patch transplantation is effective for the reconstruction of ocular surface after alkali damage probably by differentiation of ADSCs into epithelial-like cell after CSCs induced.Moreover, amnion can alleviate immuno-inflammatory response and suppress neovascularization. Key words: Adipose-derived mesenchymal stem cells; Transplantation; Amniotic membrane; Alkali burn, ocular; Differentiation; Corneal stromal cells

Detection and analysis of platelet-derived growth factor-c and vascular endothelial growth factor in ocular aqueous humor with neovascular glaucoma

Background Neovascular glaucoma (NVG) is a serious eye disease with a variety of causes.It results from the secretion of growth factors by hypoxic retinal tissue, such as vascular endothelial growth factor (VEGF), but anti-VEGF treatment alone dose not completely inhibit neovascularization.Our previous study found that platelet-derived growth factor-c (PDGF-C) is also an important factor in pathological angiogenesis.However, the role of PDGF-C in the development of NVG remains unknown. Objective This study was to quantitatively detect the levels of VEGF and PDGF-C in the aqueous humor of patients with NVG and provide a basis for the anti-angiogenesis therapy. Methods A prospective cohort study was carried out.Sixty-two eyes of 62 patients with advanced NVG and 11 control subjects with age related cataract were included in Xijing Hospital of the Fourth Military Medical University from January 2014 to August 2015.Ten of 62 NVG eyes received retinal photocoagulation and/or cryotherapy, and 16 eyes resulted from central retinal vein occlusion, 20 eyes from diabetic retinopathy, 5 eyes from postopeartion of retinal detachment, 4 eyes from Eales disease and 7 eyes from unknown cause.Iris neovascularization of grade Ⅱ was found in 13 eyes, grade Ⅲ in 29 eyes and grade Ⅳ in 10 eyes.Aqueous humor specimen was collected for 0.1-0.2 ml during the surgery, and the contents of VEGF and PDGF-C in the aqueous humor were detected by ELISA assay.Written informed consent was obtained from each subject prior to any medical procedure. Results The VEGF and PDGF-C concentrations in the aqueous humor were (1 138.17±69.31)ng/L and (29.80±1.64)ng/L in the NVG group, respectively, which were significantly higher than (679.54±49.81)ng/L and (18.60±1.85)ng/L in the control subjects (t=20.95, 20.49, both at P 0.05). Conclusions Both VEGF and PDGF-C contents in the aqueous humour are considerably elevated in NVG patients.Retinal photocoagulation and/or cryotherapy can inhibit the release of VEGF and PDGF-C in the aqueous humor.PDGF-C may be a target for the treatment of NVG. Key words: Glaucoma, neovascular; Vascular diseases/complications; Cytokines/metabolism; Vascular endothelial growth factor; Platelet-derived growth factor-c; Aqueous humor/metabolism; ELISA; Human

Vascular Endothelial Growth Factor is Increased in Aqueous Humor of Acute Primary Angle-Closure Eyes.

To measure and compare the levels of vascular endothelial growth factor (VEGF) in the aqueous humor of patients with acute primary angle closure (APAC), primary angle-closure glaucoma (PACG), and normal cataract (controls). Aqueous humor samples were prospectively collected from 38 APAC eyes, 36 PACG eyes, and 25 nonglaucomatous cataract control eyes. The levels of aqueous humor VEGF were measured using enzyme-linked immunoassays. The clinical characteristics of participants were also collected for correlation analysis. VEGF was detected in aqueous humor samples of 35 of 38 APAC patients (mean±SE of the mean, 935±258 pg/mL), 30 of 36 PACG patients (165±37.5 pg/mL), and 16 of 25 cataract controls (69.5±13.5 pg/mL). The mean concentration of VEGF in APAC eyes was 13.5 and 5.7 times higher than that in controls and PACG eyes, respectively, and these differences were statistically significant (both P<0.0167). In the correlation analysis that included all participants, the aqueous humor VEGF level was found to correlate negatively with axial length (ρ=-0.342, P=0.001), and positively with intraocular pressure (ρ=0.434, P<0.001). VEGF was significantly increased in aqueous humor of APAC eyes. An increase in aqueous humor VEGF may be the result of the characteristic ocular ischemia and hypoxia observed in APAC eyes as a consequence of sudden excessive increases in intraocular pressure during the acute episode.

The application of anti-VEGF medication for treatment of neovascular glaucoma

Neovascular glaucoma (NVG) is a refractory ophthalmopathy secondary to multiple ophthalmic and generic vascular diseases, and frequently causes the patients vision loss and impacts their quality of life. The past treatments had very high failure rate: medications did not show good effects, and surgeries led to complications such as intraoperative bleeding, postoperative serious local inflammatory reaction and filtering bleb scar etc. Its pathogenesis is that vascular endothelial growth factor (VEGF) gene overexpression caused by anoxic ischemic retinopathy increases the amount of VEGF in aqueous humor, and then stimulates neovascularization at iris and chamber angel. Anti-VEGF medications being generally applied in ophthalmology in recent years lead the treatment of NVG to a new era. This article briefly summarized the application of anti-VEGF medication in the treatment of NVG. Key words: Glaucoma, neovascular; Anti-VEGF; Treatment

A Comparison of Intravitreal Bevacizumab and Steroid Activity in an Experimental Uveitis Model

Purpose: To compare intravitreal bevacizumab (IVB) and steroid activity in an experimental uveitis (EU) model.Materials and methods: EU was induced by intravitreal injection of bovine serum albumin (BSA) at baseline. Rabbits were randomly divided into three groups (n = 8) according to treatment with a single dose of IVB, steroid or saline on day 3. Aqueous humor (AH) samples were collected periodically (baseline and days 1, 3, 10 and 33). Rabbits were sacrified and eyes were enucleated for histopathology on day 33. AH vascular endothelial growth factor (VEGF) levels and histopathological changes were subjected to statistical analysis.Results: VEGF levels increased significantly after BSA injection (day 1) when compared with baseline in all three groups. Mean VEGF levels were 794.46 pg/mL, 777.91 pg/mL and 872 pg/mL for IVB, steroid and control groups, respectively (p = 0.002, p = 0.019 and p = 0.014). Seven days after treatment (day 10), VEGF levels decreased significantly in both treatment groups. Mean VEGF levels were 0 pg/mL, 292 pg/mL and 872 pg/mL, repectively (p < 0.001, p = 0.016 and p = 0.12). On day 33, the VEGF levels and inflammation had returned to baseline levels in both treatment groups, whereas no decrease in inflammation was observed in the control group. The histopathological evaluation revealed a mild congestion in ciliary tissue with a normal retina and choroidea in IVB group, a mild congestion in ciliary tissue with moderate inflammation in the posterior vitreus and a normal retina in steroid group and a severe inflammation in ciliary tissue with moderate inflammation in the retina in control group.Conclusions: These findings suggest that IVB may be used as an alternative to steroid treatment to reduce the acute effects of inflammation in patients with uveitis in whom intraocular steroids are contraindicated.

Suppression of Intraocular Vascular Endothelial Growth Factor During Aflibercept Treatment of Age-Related Macular Degeneration

To determine the duration of suppression of aqueous humor concentrations of vascular endothelial growth factor (VEGF) in eyes with neovascular age-related macular degeneration (AMD) treated with aflibercept. Nonrandomized prospective clinical study. Twenty-seven eyes of 27 neovascular AMD patients receiving intravitreal aflibercept injections on a pro re nata regimen driven by spectral-domain optical coherence tomography (SD OCT) were included in this study. A total of 132 aqueous humor specimens were collected before intravitreal aflibercept injections and their VEGF-A concentrations assayed by multiplex bead analysis. Mean aqueous humor VEGF concentrations before treatment initiation were 90.6 ± 37.1 pg/mL (range 23.4-190.3 pg/mL). Intravitreal injection of aflibercept suppressed the aqueous VEGF concentrations to below the lower limit of quantification (<4 pg/mL) in all patients. The mean duration of VEGF suppression below the lower limit of quantification was >71 ± 18 days. The earliest time after injection at which the VEGF concentration recovered to above the lower limit of quantification was 55 days in 1 patient and >56 days, the recommended aflibercept treatment interval, in 20 patients. The aqueous VEGF recovery status of 6 patients was uncertain after 56 days. On average, VEGF concentrations in the aqueous humor were suppressed below the lower limit of quantification after intravitreal aflibercept injections for about 10 weeks. This aqueous suppression time suggests durable VEGF inhibition for most patients dosed with aflibercept every 8 weeks.

Treatment of Diabetic Macular Edema With a Designed Ankyrin Repeat Protein That Binds Vascular Endothelial Growth Factor: A Phase I/II Study

To evaluate the safety and bioactivity of MP0112, a designed ankyrin repeat protein (DARPin) that specifically binds vascular endothelial growth factor (VEGF) in patients with diabetic macular edema (DME). DARPins are a novel class of proteins selected for specific, high-affinity binding to a target protein. Phase I/II, open-label, multicenter dose-escalation trial. After a single intravitreal injection of MP0112, the main outcomes were safety assessments, aqueous MP0112 levels, change in best-corrected visual acuity (BCVA), and foveal thickness measured by optical coherence tomography. Six cohorts were planned, but only 3 were enrolled (0.04, 0.15, 0.4mg), because a maximally tolerated dose of 1.0mg was identified in a parallel age-related macular degeneration trial. Median aqueous concentration of MP0112 was 555 nM 1week and >10 nM in 3 of 4 patients 12weeks post injection of 0.4mg. Median BCVA improvement at week 12 was 4, 6, and 10 letters in cohorts 1, 2, and 3. Ocular inflammation was observed in 11 patients (61%) and was severe in 1. High-resolution chromatography separated proinflammatory impurities from MP0112, resulting in a new formulation. A single intraocular injection of 0.4mgMP0112 resulted in levels above the half-maximal inhibitory concentration and neutralization of VEGF in aqueous humor for 8-12weeks. Despite inflammation in several patients, there was prolonged edema reduction and improvement in vision in several patients. The source of the inflammation was eliminated from a new preparation that is being tested in an ongoing clinical trial.

Increased Nitric Oxide and Vascular Endothelial Growth Factor Levels in the Aqueous Humor of Patients with Coats' Disease

To determine the aqueous humor levels of nitric oxide (NO) and vascular endothelial growth factor (VEGF) in the eyes of patients with Coats' disease and study the correlation between these levels. Samples of aqueous humor were obtained from 7 patients with Coats' disease and 15 age-matched patients with congenital cataracts as controls. Nitrite and nitrate (NOx), the stable end products of NO, were detected by the Griess reaction, and VEGF levels were assessed by enzyme-linked immunosorbent assay. The aqueous humor NOx and VEGF levels were elevated in the eyes of patients with Coats' disease compared with those of controls (P=0.001 and P<0.001, respectively). The median NOx level was 55.2 μM (range, 23.0-75.3 μM) in the Coats' disease group and 18.8 μM (range, 8.7-36.2 μM) in the control group. The median VEGF level was 731.7 pg/mL (range, 288.3-1364.3 pg/mL) in the Coats' disease group and 33.3 pg/mL (range, 9.0-96.8 pg/mL) in the control group. No correlation was observed between the aqueous humor concentrations of NOx and VEGF. NOx and VEGF are increased but not related in the aqueous humor samples of patients with Coats' disease. NO and VEGF may play roles in the pathogenesis of Coats' disease. Further studies are needed to clearly elucidate the relationship among VEGF, NO, and other cytokines in Coats' disease.

Aqueous humor vascular endothelial growth factor in dogs: association with intraocular disease and the development of pre‐iridal fibrovascular membrane

To examine the concentrations of vascular endothelial growth factor (VEGF) in aqueous humor of dogs with intraocular disease and to evaluate the association of aqueous humor VEGF with pre-iridal fibrovascular membrane (PIFM) formation. Two hundred and twenty six aqueous humor samples and 101 plasma samples were collected from 178 dogs with a variety of intraocular diseases (including cataract, primary glaucoma, uveitic glaucoma, aphakic/pseudophakic glaucoma, retinal detachment, lens luxation, and intraocular neoplasia), and aqueous humor was collected from 13 ophthalmically normal control dogs. Systemic disease status and administration of select medications were recorded. Aqueous and plasma VEGF was assayed via enzyme-linked immunosorbant assay validated for canine VEGF. Available histopathology samples were examined for the presence of PIFM. Where present, PIFMs were categorized as none, cellular, vascular or fibrous, and fibrovascular. Data were evaluated by mixed model anova, with application of Tukey-Kramer adjustment for multiple comparisons. There was no association between aqueous humor and plasma VEGF levels. Compared with normal controls, aqueous humor VEGF was significantly elevated for all intraocular diseases (P < 0.05) except for primary and diabetic cataracts. Systemic disease and administered medications had no significant effect on aqueous humor VEGF concentration. Compared to dogs without PIFM, aqueous humor VEGF was significantly higher in dogs with fibrovascular PIFM (P = 0.001), but not cellular (P = 0.1704) or fibrous/vascular PIFM (P = 0.0667). These findings confirm that VEGF is commonly elevated in aqueous humor of dogs with intraocular disease and likely plays a role in the causation or progression of a variety of intraocular disorders, including the development of PIFM.

Vascular endothelial growth factor in diabetic and nondiabetic canine cataract patients

To measure vascular endothelial growth factor (VEGF) levels in aqueous humor, serum, and plasma in diabetic and nondiabetic cataractous dogs. Canine VEGF was assayed in the plasma and serum of 32 dogs (20 diabetics; 12 nondiabetics) and aqueous humor in 57 eyes of those dogs (39 diabetic; 18 nondiabetic) undergoing phacoemulsification, using a commercial canine VEGF assay. Statistical analysis was performed using Fisher's PLSD, t-test, and regression analysis to compare values by diabetic status, duration of diabetes, age, weight, gender, left vs. right eye, and blood clarity. Plasma, but not serum or aqueous humor VEGF values of diabetics were significantly greater than nondiabetics (P = 0.019). Older nondiabetics (10-15 years) had higher plasma VEGF values than younger (0-5 and 5-10 years) dogs (P = 0.0002 and 0.0001, respectively). There was no significant difference in aqueous humor VEGF between left and right eyes in all patients. Serum and plasma, but not aqueous humor, VEGF values in females were significantly higher than males in both groups. Similar to human diabetic patients, VEGF aqueous humor values in all dogs are significantly higher than blood values. Aqueous humor VEGF values in human diabetics are elevated and correlate with the severity of diabetic retinopathy. However, aqueous humor values of VEGF in diabetic dogs are not greater than nondiabetics and may serve to protect the dog against development of diabetic retinopathy.

Aqueous Humor and Plasma Levels of Vascular Endothelial Growth Factor and Nitric Oxide in Patients With Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma

To investigate levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in the aqueous humor and plasma of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG), compared with controls. This prospective study involved 37 patients with PXS, 15 with PXG, and 32 control subjects in whom cataract surgery was indicated. Aqueous humor and plasma VEGF and NO levels were measured with enzyme-linked immunosorbent assay and chemiluminescence methods, respectively. Aqueous humor and plasma VEGF concentrations were higher in patients with PXS and PXG than in controls (P<0.001). Aqueous humor NO concentrations were higher in patients with PXS and PXG than in controls (P<0.05 and P=0.001, respectively). Plasma NO concentrations did not differ between the 3 groups. Aqueous humor and plasma VEGF and NO levels were not significantly different in patients with PXS versus PXG. VEGF and NO levels showed no significant correlation among the 3 groups (P>0.05). Elevated aqueous humor VEGF and NO levels and plasma VEGF concentrations in eyes with PXS and PXG can be explained by the ischemic nature of these disorders. The lack of correlation between VEGF and NO levels may indicate impaired downregulation, which may have a role in the progression to PXG.

Aqueous Humor Levels of Vasoactive Molecules Correlate with Vitreous Levels and Macular Edema in Central Retinal Vein Occlusion

Aqueous levels of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) are associated with the severity of macular edema in patients with central retinal vein occlusion (CRVO). We investigated whether aqueous and vitreous levels of these molecules were correlated in CRVO patients. Aqueous and vitreous samples were obtained during cataract surgery and vitreous surgery from 17 patients (17 eyes) with CRVO and macular edema. The levels of VEGF and IL-6 in aqueous humor, vitreous fluid, and plasma were determined by enzyme-linked immunosorbent assay. The aqueous levels of VEGF and IL-6 were significantly correlated with the vitreous levels of these molecules (rho=0.8799, p=0.0004 and rho=0.8088, p=0.0012, respectively). Vitreous levels of VEGF and IL-6 were significantly higher in CRVO patients with retinal ischemia than in those without ischemia (p=0.0013 and p=0.0009, respectively), as were the aqueous levels of VEGF and IL-6 (p=0.0026, p=0.0120, respectively). Furthermore, both the aqueous and vitreous levels of VEGF and IL-6 were significantly correlated with the severity of macular edema (rho=0.7181, p=0.0041; rho=0.8260, p=0.0010; rho=0.5564, p=0.0260; and rho=0.6599, p=0.0039, respectively). Our results suggest that aqueous levels of VEGF and IL-6 may reflect the vitreous levels of these molecules. Measurement of VEGF and IL-6 in the aqueous humor may be clinically useful to assess the severity of macular edema in patients with CRVO.

Level of Vascular Endothelial Growth Factor in Aqueous Humor and Surgical Results of Ahmed Glaucoma Valve Implantation in Patients With Neovascular Glaucoma

To determine the associations between the levels of growth factors in aqueous humor and the surgical outcomes of Ahmed glaucoma valve implantation in patients with neovascular glaucoma (NVG). From 19 NVG eyes of 19 patients, a sample of aqueous humor was taken just before Ahmed glaucoma valve implantation. Levels of vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-beta1, and TGF-beta2 in aqueous humor aspirates were measured using a sandwich enzyme-linked immunosorbent assay method. When the postoperative intraocular pressures were >or=21 mm Hg with or without antiglaucoma medications at 2 successive visits or when any other surgical interventions were needed to lower intraocular pressure, that surgery was considered a failure. After patients were classified into success versus failure groups, the levels of the growth factors between the 2 groups was compared. The cumulative probability of success according to Kaplan-Meier analysis was also determined. Mean postoperative follow-up period was 40.9+/-19.6 months and cumulative probability of success was 43% at 57 months after surgery. Mean VEGF level in the failure group was higher than that of the success group (P=0.014). However, there was no statistical difference in the levels of TGF-beta1, TGF-beta2, and protein between 2 study groups (all P>0.05). The level of VEGF in aqueous humor was significantly higher in the failure group after the Ahmed glaucoma implantation compared with the success group. Our results imply that VEGF may play a role in determining surgical success after Ahmed valve implantation in patients with NVG.