Levels of angiogenesis-related vascular endothelial growth factor family in neovascular glaucoma eyes

Measurement of Aqueous Humor Viscosity in an Experimental Rabbit Model With Corneal Neovascularization

Purpose

This study investigated the relationship between aqueous humor (AH) viscosity and vascular endothelial growth factor-A (VEGF-A) in a corneal neovascularization (CNV) model.

Methods

Ten female New Zealand rabbits were divided into two groups (n = 5 each). CNV was induced by alkaline burns on the right corneas of group B, whereas group A underwent a sham procedure. After 14 days, at least 150 µL of AH was extracted from both eyes. VEGF-A concentration was measured using ELISA, and AH viscosity was determined using a viscometer. Correlations between VEGF-A concentration, total protein concentration, and AH viscosity were assessed.

Results

VEGF-A concentration was significantly elevated in CNV-induced eyes than in noninduced eyes (6029.06 ± 7116.50 pg/mL vs. 115.63 ± 33.19 pg/mL, P < 0.01). Total protein concentration was also elevated in CNV-induced eyes (11.66 ± 9.86 mg/mL) than in noninduced eyes (0.69 ± 0.06 mg/mL, P < 0.01), and correlated positively with VEGF-A (r = 0.84, P < 0.01). AH viscosity was significantly increased in CNV-induced eyes (1.82 ± 1.28 mPa-s) compared to noninduced eyes (1.05 ± 0.01 mPa-s, P < 0.01) and correlated strongly with VEGF-A concentration in CNV-induced eyes (r = 1.00, p = 0.02).

Conclusions

AH viscosity positively correlated with VEGF-A concentration, particularly in CNV-induced eyes with elevated VEGF-A levels.

Translational Relevance

The correlation between VEGF-A levels and AH viscosity in an experimental model of corneal neovascularization suggests that AH viscosity could serve as a biomarker for predicting IOP or surgical outcomes in conditions like neovascular glaucoma.

Two-year outcomes of patients presenting to Sydney Eye Hospital with neovascular glaucoma

BACKGROUND

Neovascular glaucoma (NVG) is a sight-threatening condition that is often refractory to treatment. Current management principles are yet to be standardized due to lack of evidence. We studied the interventions used to treat NVG at Sydney Eye Hospital (SEH) and the two-year surgical outcomes.

METHODS

We performed a retrospective audit of 67 eyes of 58 patients with NVG from January 1, 2013, to December 31, 2018. Intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of medications, repeat surgery, recurrent neovascularization, loss of light perception and pain were studied.

RESULTS

The average age of the cohort was 59.67 years (SD 14.22). The most common etiologies were proliferative diabetic retinopathy (35 eyes; 52.2%), central retinal vein occlusion (18 eyes; 26.9%) and ocular ischemic syndrome (7 eyes; 10.4%). 70.1% of eyes (47) received vascular endothelial growth factor injections (VEGFI), 41.8% (28 eyes) received pan-retinal photocoagulation (PRP) and 37.3% (25 eyes) received both prior to or within the first week of presentation to SEH. The most common initial surgical interventions were trans-scleral cyclophotocoagulation (TSCPC) (36 eyes; 53.7%) and Baerveldt tube insertion (18 eyes; 26.9%). 62.7% of eyes (42 eyes) failed (IOP > 21 or < 6 mmHg for two consecutive reviews, further IOP-lowering surgery or loss of light perception) during follow-up. Initial TSCPC failed in 75.0% (27/36 eyes) compared with 44.4% (8/18 eyes) after Baerveldt tube insertion.

CONCLUSION

Our study reinforces the refractory nature of NVG, often despite intensive treatment and surgery. Improvements in patient outcomes may be achieved with earlier consideration of VEGFI and PRP. This study identifies the limitations of surgical interventions for NVG and highlights the need for a standardized management approach.

Anti-scarring effects of conbercept on human Tenon's fibroblasts: comparisons with bevacizumab

BACKGROUND

Safely inhibiting the formation of scar in the glaucoma filtration surgery (GFS) has always been an issue for clinical glaucoma doctors. Anti-vascular endothelial growth factor (VEGF) agents can reduce angiogenesis, and anti-placental growth factor (PIGF) agents can affect reactive gliosis. However, the effect of conbercept, which can bind to both VEGF and PIGF, on human Tenon's fibroblasts (HTFs) is unknown.

METHODS

HTFs were cultured in vitro and treated with conbercept or bevacizumab (BVZ). No drug was added to the control group. The effects of drugs on cell proliferation were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the collagen type I alpha1(Col1A1) mRNA expression level was measured using quantitative polymerase chain reaction (qPCR). HTF cell migration after drug interventions was evaluated using the scratch wound assay along with the measurement of the expression levels of VEGF and PIGF in human umbilical vein endothelial cells (HUVECs) using enzyme-linked immunosorbent assay, as well as the detection of the VEGF(R) mRNA expression level in HTFs using qPCR.

RESULTS

After the addition of conbercept (0.01, 0.1, and 1 mg/mL) to the cultured HTFs or HUVECs, no significant cytotoxicity was observed compared with the control group, while the cytotoxicity of 2.5 mg/mL BVZ on HTFs was obvious. Conbercept significantly inhibited HTF cell migration and Col1A1 mRNA expression level in HTFs. It was superior to BVZ in inhibiting HTF migration. After the intervention with conbercept, the expression level of PIGF and VEGF in HUVECs significantly decreased; and the inhibitory effect of conbercept on the expression level of VEGF in HUVECs was weaker than that of BVZ. Conbercept was more advantageous than BVZ in inhibiting the expression level of VEGFR-1 mRNA in HTFs. However, its effect in terms of inhibiting the expression level of VEGFR-2 mRNA in HTFs was weaker than that of BVZ.

CONCLUSION

The results suggested the low cytotoxicity and significant anti-scarring effect of conbercept in HTF with significant anti-PIGF and inferior anti-VEGF effects compared with BVZ, thus providing a better understanding of the role of conbercept in the GFS wound healing process.

Intravitreal Injection of Conbercept Combined with Minimally Invasive Photocoagulation and Phacoemulsification Intraocular Lens Implantation in the Treatment of Neovascular Glaucoma Complicated with Cataract

Background

Neovascular glaucoma (NVG) is a complex refractory glaucoma with a high rate of blindness. Compaq is an anti-VEGF agent that has been used in clinical NVG therapy.

Objective

This study aims to investigate the effect of intravitreal injection of conbercept combined with minimally invasive photocoagulation and phacoemulsification intraocular lens implantation in the treatment of NVG complicated with cataracts.

Methods

A total of 84 patients with NVG complicated with cataracts who were admitted to our hospital from September 2019 to September 2021 were selected. According to the random number table method, they were divided into the study group and the control group, with 42 cases in each. The control group underwent minimally invasive photocoagulation combined with phacoemulsification and intraocular lens implantation. The study group was given an intravitreal injection of conbercept first, followed by minimally invasive photocoagulation combined with phacoemulsification and intraocular lens implantation 3 to 7 days after the injection. The intraocular pressure and visual acuity of the two groups before surgery, 1 week, 1 month, 3 months, and 6 months after the operation were compared. The levels of serum vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) were compared between the two groups before the operation and 1 week after the operation. The incidence of postoperative complications in the two groups was statistically compared.

Results

At 1 week, 1 month, 3 months, and 6 months after the operation, the intraocular pressure of the study group was lower than that of the control group, and the visual acuity was better than that of the control group (P < 0.05); one week after the operation, the serum levels of VEGF and IL-6 in the study group were lower than those in the control group (P < 0.05); there was no significant difference in the incidence of complications between the two groups (P > 0.05).

Conclusions

Intravitreal injection of conbercept combined with minimally invasive photocoagulation and phacoemulsification intraocular lens implantation in the treatment of NVG complicated with cataract can improve the levels of serum inflammatory factors and vasoactive substances, effectively reduce intraocular pressure, and improve visual acuity.

Modified Trabeculectomy versus Glaucoma Drainage Implant Surgery: A Retrospective Comparative Study for Refractory Glaucoma Treatment

Purpose

To observe and compare the efficacy of modified trabeculectomy (TE), Ahmed drainage valve implantation (AGV), and EX-PRESS glaucoma shunt for refractory glaucoma (RG).

Methods

The study population of this retrospective study comprised 73 patients (76 eyes) who were suffering from RG and treated with modified TE, AGV, and EX-PRESS glaucoma shunt in our hospital from October 2012 to October 2020. The number of cases who underwent modified TE, AVG, and EX-PRESS glaucoma shunt was 36 (38 eyes). 19 (20 eyes), and 18 patients (18 eyes), respectively. The intraocular pressure (IOP), best-corrected visual acuity (BCVA), postoperative antiglaucoma medications, filter bubble morphology, anterior chamber depth (ACD), successful rate, and postoperative complications were recorded and statistically analyzed preoperative and 1 d, 1 w, 1 mon, 3 mon, 6 mon, and the end follow-up after operation.

Results

The BCVA differed insignificantly among the three cohorts before and 6 months after surgery. Compared to preoperative BCVA, the postoperative BCVA of the three groups had no statistical significance. An obvious reduction in IOP was observed in all the three group after operation (P < 0.05). An obvious decrease in antiglaucoma medications was observed after surgery in all the three groups (P < 0.05). The AGV group showed deeper ACD postoperatively, while no marked difference was found in postoperative ACD in the other two groups. The total success rates in modified TE and AGV groups were slightly higher than those in the EX-PRESS group. The three groups differed insignificantly in filter bubble morphology after operation.

Conclusion

Modified TE, AGV, and EX-PRESS glaucoma shunt showed equivalent efficacy for RG, which could validly reduce IOP and postoperative antiglaucoma medications. However, the success rates of modified TE and AGV were slightly higher than those of EX-PRESS glaucoma shunt in the last follow-up, and their complications were slightly less than those of the EX-PRESS glaucoma shunt.

Comparison of conbercept and ranibizumab combined mitomycin C-augmented trabeculectomy for neovascular glaucoma

PURPOSE

To compare the efficacy and security of conbercept and ranibizumab combined with trabeculectomy and panretinal photocoagulation for neovascular glaucoma (NVG).

METHODS

One hundred and sixty patients with NVG were randomly divided into a conbercept group comprised of 80 patients and a ranibizumab group comprised of 80 patients. The postoperative and preoperative visual acuities, intraocular pressures frequency of anti-glaucoma medications, and surgical complications were recorded. The expressions of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (FLT-1), and placenta-like growth factor (PLGF) in the aqueous humor were determined using an enzyme-linked immunosorbent assay. Examining the fundus and obtaining photographs used indirect ophthalmoscopy. Kaplan-Meier and log-rank analyses estimated the success rates.

RESULTS

All patient follow-up periods were at 1 year. The differences observed in IOP and the frequencies of anti-glaucoma medications at various follow-up time points were not statistically significant (all P > 0.05). The differences observed in both the group visual acuities at various follow-up time points were not statistically significant (P > 0.05). Rates of surgery complications were 18.75% and 25.00% in the conbercept group and ranibizumab group, respectively. The expressions of VEGF, FLT-1, and PLGF significantly decreased (all P < 0.05). The recurrence percentages were 30.00% and 36.25% after conbercept and ranibizumab treatment, respectively.

CONCLUSION

The conbercept effects were similar with that of ranibizumab. Intravitreal injection of conbercept was effective for NVG treatment, which provides a new therapeutic drug for NVG treatment.

Biological drug therapy for ocular angiogenesis: Anti-VEGF agents and novel strategies based on nanotechnology

Currently, biological drug therapy for ocular angiogenesis treatment is based on the administration of anti‐VEGF agents via intravitreal route. The molecules approved with this purpose for ocular use include pegaptanib, ranibizumab, and aflibercept, whereas bevacizumab is commonly off‐label used in the clinical practice. The schedule dosage involves repeated intravitreal injections of anti‐VEGF agents to achieve and maintain effective concentrations in retina and choroids, which are administrated as solutions form. In this review article, we describe the features of different anti‐VEGF agents, major challenges for their ocular delivery and the nanoparticles in development as delivery system of them. In this way, several polymeric and lipid nanoparticles are explored to load anti‐VEGF agents with the aim of achieving sustained drug release and thus, minimize the number of intravitreal injections required. The main challenges were focused in the loading the molecules that maintain their bioactivity after their release from nanoparticulate system, followed the evaluation of them through studies of formulation stability, pharmacokinetic, and efficacy in in vitro and in vivo models. The analysis was based on the information published in peer‐reviewed published papers relevant to anti‐VEGF treatments and nanoparticles developed as ocular anti‐VEGF delivery system.

Aqueous Inflammation and Ischemia-Related Biomarkers in Neovascular Glaucoma with Stable Iris Neovascularization

Purpose: To characterize the aqueous levels of inflammation and ischemia-related biomarkers in a spectrum of retinal ischemic conditions, including neovascular glaucoma (NVG) with stable iris neovascularization after pan retinal photocoagulation (PRP) and anti-VEGF treatment. Methods: Aqueous samples were collected from 139 eyes including NVG (n = 12), stable NVG (n = 26), CRVO (n = 11), NPDR (n = 18), PACG (n = 18), PDR (n = 25), BRVO (n = 7) and cataract (n = 22). The levels of VEGF-A, IL-8 and EPO were measured with ELISA. Results: Aqueous VEGF-A significantly decreased after anti-VEGF and PRP, from 983.79 ± 821.16 pg/ml in the NVG group (n = 11) to 256.50 ± 51.14 pg/ml in the stable NVG group (n = 24) (P = .015). Aqueous VEGF-A in stable NVG group (256.50 ± 51.14 pg/ml, n = 24) was significantly higher (ANOVA, P < .001) than in CRVO (212.10 ± 19.84 pg/ml, n = 7, P = .017), NPDR (221.18 ± 38.21 pg/ml, n = 14, P = .015), BRVO (213.14 ± 48.50 pg/ml, n = 6, P = .028) and cataract group (185.30 ± 34.35 pg/ml, n = 22, P < .001). Aqueous IL-8 in stable NVG group (74.82 ± 10.78 pg/ml, n = 24) was significantly higher (ANOVA, P < .001) than in CRVO (65.19 ± 15.34 pg/ml, n = 11, P = .032) and cataract group (54.11 ± 12.28 pg/ml, n = 22, P < .001). Aqueous EPO in stable NVG group (17.48 ± 3.02 pg/ml, n = 24) was significantly higher (ANOVA, P < .001) than in BRVO (14.98 ± 2.57 pg/ml, n = 7, P = .034) and cataract group (13.50 ± 2.65 pg/ml, n = 22, P < .001). Aqueous concentrations of VEGF-A and IL-8 correlated positively with IOP (r = 0.413, P < .001, r = 0.349, P < .001, respectively, r = correlation coefficient). VEGF-A correlated positively with IL-8 and EPO (P < .001, P = .002, respectively). IL-8 correlated positively with EPO (P < .001). Conclusions: The aqueous levels of VEGF-A, IL-8 and EPO in NVG patients with stable iris neovascularization, who had received PRP and anti-VEGF, were still significantly higher than in control groups with some retinal ischemic conditions.

Angiogenic and inflammatory biomarker levels in aqueous humor and vitreous of neovascular glaucoma and proliferative diabetic retinopathy

PURPOSE

To explore the relationships between the aqueous and vitreous levels of vascular endothelial growth factor-A (VEGF-A), interleukin-8 (IL-8), placental growth factor (PlGF) and erythropoietin (EPO) in proliferative diabetic retinopathy (PDR) and neovascular glaucoma (NVG).

METHODS

Aqueous and vitreous samples were obtained from patients with PDR and NVG during surgery. Aqueous and vitreous concentrations of VEGF-A, IL-8, PlGF and EPO were measured via enzyme-linked immunosorbent assay.

RESULTS

No correlation between the aqueous and vitreous levels of VEGF-A, IL-8, PlGF or EPO was found in both the PDR and the NVG eyes. Aqueous VEGF-A was significantly higher in the NVG group (317.55 ± 36.25 pg/ml, n = 15) than that in the PDR group (256.23 ± 46.11 pg/ml, n = 17, P < 0.001). The level of VEGF-A in aqueous (317.55 ± 36.25 pg/ml, n = 15) was significantly higher than that in vitreous (224.74 ± 60.32 pg/ml, n = 15, P < 0.001) in NVG patients. The level of IL-8 in aqueous (76.55 ± 10.88 pg/ml, n = 17) was significantly higher than that in vitreous (63.55 ± 10.74 pg/ml, n = 17, P = 0.001) in PDR patients. The level of EPO in aqueous (18.62 ± 2.87 mIU/ml, n = 15) was significantly higher than that in vitreous (15.97 ± 3.11 mIU/ml, n = 15, P = 0.022) in NVG patients. The ratio of aqueous versus vitreous for VEGF-A was significantly higher in the NVG group (1.475 ± 0.289, n = 15) than that in the PDR group (0.996 ± 0.227, n = 17, P < 0.001).

CONCLUSION

Aqueous levels of VEGF-A, IL-8, PlGF and EPO do not correlate with vitreous levels of those proteins. The relationship between protein levels in aqueous humor and vitreous might be dependent on different disease status or protein types investigated.

What is the impact of intravitreal injection of conbercept on neovascular glaucoma patients: a prospective, interventional case series study

Background

The aim of the present study was to evaluate the efficacy and safety of intravitreal conbercept combined with trabeculectomy and panretinal photocoagulation for neovascular glaucoma (NVG).

Methods

Fifty patients (54 eyes) with NVG were included in this prospective study. Fifty-two eyes initially underwent intravitreal conbercept (0.5 mg/0.05 ml) treatment followed by trabeculectomy and panretinal photocoagulation. Preoperative and postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP), the number of antiglaucoma medications, and surgical complications were recorded. The levels of VEGF-A, TGF-β₁ and PLGF in aqueous humour samples collected during surgery were measured by enzyme-linked immunosorbent assay (ELISA). Light microscopy and transmission electron microscopy were used to observe the surgically excised trabecular tissue; enucleation was performed in 2 eyes, and light microscopy was used as the histopathological control.

Results

The follow-up period after trabeculectomy was 1 year. Of the 52 eyes, 39 completed 1 year of follow-up, and 13 were lost to follow-up. Recurrence of iris neovascularization was observed in 5 eyes, 9 had hyphema, 16 had filter-bled scarring, and no eye had complications attributable to the drug. The mean IOP was reduced from 48.1 ± 14.2 to 23.2 ± 8.7 mmHg, and the mean number of antiglaucoma medications used decreased from 3.0 (3.0, 4.0) to 1.0 (0.0, 1.0) after 1 year (both P < 0.05). The complete success rate was 76.9, 76.9, 71.0, 51.6, and 32.3% at 1 week, 1 month, 3 months, 6 months and 12 months, respectively, when the cut-off IOP was 18 mmHg. After patients underwent intravitreal injection, the concentrations of VEGF-A and TGF-β₁ in the aqueous humour in NVG patients decreased from 168.8 ± 13.4 and 159.6 ± 15.4 pg/ml to 160.2 ± 7.6 and 151.9 ± 2.3 pg/ml, respectively (both P < 0.05). Light microscopy revealed neovascularization regression in the iris in specimens treated with intravitreal conbercept. Electron microscopy revealed trabecular endothelial cell degeneration in the conbercept-treated specimens.

Conclusions

Our initial findings suggest that intravitreal conbercept is an effective treatment for managing NVG that has fewer short-term postoperative complications.

Trial registration

Current Controlled Trials ChiCTR1800019918, 8 December 2018, retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12886-019-1138-6) contains supplementary material, which is available to authorized users.

Expression of platelet-derived growth factor-C in aqueous humor of patients with neovascular glaucoma and its correlation with vascular endothelial growth factor

AIM

The aim of this study was to investigate the expression of platelet-derived growth factor-C in aqueous humor of patients with neovascular glaucoma and its correlation with vascular endothelial growth factor.

METHODS

This study involved 62 eyes of 62 patients with advanced neovascular glaucoma requiring transscleral cyclophotocoagulation. Aqueous humor was collected through paracentesis. Samples from 11 eyes of 11 patients with age-related cataract were collected as control. Concentrations of platelet-derived growth factor-C and vascular endothelial growth factor in aqueous humor were quantified by enzyme-linked immunosorbent assay. Meanwhile, the correlations between the concentrations of platelet-derived growth factor-C and vascular endothelial growth factor were analyzed. The elements including retinal photocoagulation treatment, iris neovascularization grade, and primary fundus disease were also studied to find out their roles in the concentrations of the two factors.

RESULTS

The vascular endothelial growth factor and platelet-derived growth factor-C concentrations in aqueous humor from controls were (679.54 ± 49.81) pg/mL and (18.60 ± 1.85) pg/mL, respectively. Both of them were significantly lower than neovascular glaucoma patients (p < 0.001). The vascular endothelial growth factor and platelet-derived growth factor-C concentrations of neovascular glaucoma patients treated with retinal photocoagulation were (1095.99 ± 52.71) pg/mL and (28.55 ± 0.94) pg/mL, respectively, which were both significantly lower than those of untreated neovascular glaucoma patients, (1146.28 ± 69.57) pg/mL and (30.04 ± 1.64) pg/mL (p = 0.008, p = 0.034). There was a weak correlation between the expression level of vascular endothelial growth factor and platelet-derived growth factor-C in aqueous humor with neovascular glaucoma (r = 0.346, p = 0.006). However, iris neovascularization grade and primary fundus disease were not significant elements in the expression level of vascular endothelial growth factor and platelet-derived growth factor-C.

CONCLUSION

Higher concentrations of vascular endothelial growth factor and platelet-derived growth factor-C were found in aqueous humor of patients with neovascular glaucoma compared with control, which could be lowered by retinal photocoagulation to some extent. Platelet-derived growth factor-C inhibitors may be another potential target for ocular neovascular diseases.

Ahmed glaucoma valve implantation versus suprachoroidal silicone tube implantation following the injection of bevacizumab into the anterior chamber in patients with neovascular glaucoma

PURPOSE

This study compared the efficacy and safety of Ahmed glaucoma valve (AGV) implantation versus suprachoroidal silicone tube (SST) implantation after the injection of bevacizumab into the anterior chamber in patients with neovascular glaucoma.

METHODS

Patients were randomly assigned to undergo AGV or SST implantation. Bevacizumab was injected into the anterior chamber at a dosage of 1.25 mg/0.1 mL, 1 week before surgery. Intraocular pressure (IOP) control, complication, and success rates were compared between the groups. Success was defined as a final IOP > 5 mmHg, < 22 mmHg with or without any antiglaucoma drug.

RESULTS

A total of 23 patients were enrolled in the study, including 13 (56.5%) in the AGV group (group 1) and 10 (43.5%) in the SST group (group 2). The mean baseline IOP was 42.0 ± 9.1 mmHg in group 1 and 39.5 ± 10 mmHg in group 2 (p > 0.05). The mean IOP was 16.9 ± 7.0 mmHg in group 1 and 12.5 ± 6.7 mmHg in group 2 on the first day after surgery. After a mean follow-up period of 19.4 ± 5.2 months, success was achieved in 12 (92.3%) patients in group 1 and in 1 (10%) patient in group 2. There was a statistically significant difference in terms of the success rate between groups (p < 0.05). Complications included hyphema in three (23%) patients, obstruction of the AGV tube by iris tissue in one (7.7%) patient, and tube exposure in one patient (7.7%) in group 1. Suprachoroidal silicone tube dislocation to the anterior chamber was observed in one (10%) patient in group 2.

CONCLUSION

AGV implantation after the injection of bevacizumab into the anterior chamber had a higher success rate than SST implantation. Complications were seen more frequently in the AGV group.

Potential effect on molecular pathways in different targeted genes in the VEGF family in retina - From the genomic point of view

This study's goal is to determine similarities and differences in the molecular pathways or potential functions of the various targeted regions or genes of the Vegf family-VegfA, VegfB, VegfC, and Pgf-using the BXD genetic reference panel. Data from whole genome expression profiles of retinas from the well-characterized mouse recombinant inbred (RI) strain population derived from C57BL/6J X DBA/2J (BXD) were analyzed. Multiple analytical tools and statistical strategies were used to investigate the expression level. The expression Quantitative Trait Loci (QTLs) of these probes were mapped and compared. Our data showed that VegfA2 has the highest expression levels among all probes of Vegf genes. The expression levels of Vegf family genes are not significantly correlated. In the overall comparison, expression levels of VegfA1 and VegfA2 are positively correlated (R = 0.540). The expression levels of VegfB and VegfC are weakly correlated (R = 0.360). VegfC is also weakly correlated with the expression levels of Pgf (R = 0.324). The interaction of VegfB- and VegfA2-associated 50a2 genes was very weak (R50 ab = 0.3129). The interaction of top VegfB-associated 50b genes with VegfA2 has a reciprocal negative impact (R50ba = -0.42758). The VegfC-associated top 50c genes are strongly correlated with VegfB (R50 cb = 0.8159), while they are negatively correlated with VegfA2 (R50ca = -0.1450). Expression quantitative trait loci (eQTL) analysis suggested that the regulatory mechanisms for the expression levels of these genes in the Vegf family are different from each other. The expression level of VegfA associates with a group of genes that are not associated with other genes in the Vegf family.

Assessing the role of ranibizumab in improving the outcome of glaucoma filtering surgery and neovascular glaucoma

INTRODUCTION

Ranibizumab was the first anti-vascular endothelial growth factor (VEGF) agent approved for the treatment of neovascular age-related macular degeneration. The use of ranibizumab and other anti-VEGF medications in recent years has revolutionized the treatment of several sight-threatening retinal disorders. Emerging evidence has demonstrated that anti-VEGF treatment can offer advantages in the management of other ocular conditions where VEGFs play a key role: ocular scarring following glaucoma filtering surgery and neovascular glaucoma (NVG). Areas covered: We critically review available evidence on the use of ranibizumab as a wound healing modulator in glaucoma filtering surgery and as an adjunct in the management of NVG. Expert opinion: Based on the available evidence and the authors' clinical experience, ranibizumab is a valuable adjunct in the management of NVG. In glaucoma filtering surgery, however, the role of ranibizumab is less clear and does not provide a significant advantage over mitomycin C. Drawbacks for its use in glaucoma include cost, its off-label use, uncertainty and limited evidence on the various routes of administration, the optimal dosing schemes and its toxicity profile. Future advances in ranibizumab delivery systems allowing less frequent dosing may change this treatment paradigm.

Vascular endothelial growth factors and placenta growth factor in retinal vasculopathies: Current research and future perspectives

Vision loss due to disease or degeneration of the eye (retina, choroid, retinal veins, or macula) is a leading cause of blindness worldwide. In most cases, vision-threatening ocular diseases are accompanied by abnormal changes in the vasculature of the eye, especially the retina, and these conditions are collectively referred to as retinal vasculopathies. Impaired blood supply or hypoxia stimulates angiogenesis in the vascular and non-vascular sections of the eye, which results in neovascularization, leading to conditions such as diabetic retinopathy or age-related macular degeneration. Studies show that vascular endothelial growth factors: VEGF-A, VEGF-B, and placental growth factor (PlGF) are elevated in these diseases, and hence, these factors could be used as markers for disease prognosis and therapy. In this review, we discuss the function of these growth factors in normal development and disease, with focus on ocular disorders and emphasize the importance of accurately determining their levels in the vitreous and serum of patients for correct diagnosis and therapy.

Role of Platelet Parameters on Neovascular Glaucoma: A Retrospective Case-Control Study in China

Purpose

Retinal vein occlusion (RVO) and diabetic retinopathy (DR) are two major sight-threatening diseases which may lead to neovascular glaucoma (NVG). The aim of this study was to explore the association between platelet parameters and NVG.

Methods

A total of 185 subjects were enrolled for the study from January, 2012 to December, 2015 at the Eye-ENT Hospital of Fudan University. Patients include those with NVG secondary to RVO (RVO group, n = 38), patients with NVG secondary to DR (DR group, n = 47), diabetics mellitus without retinopathy (DM group, n = 52), and healthy individuals (control group, n = 48). A complete ophthalmological examination including visual field examination, A-scan ultrasound, Fundus photography, and measurement of platelet parameters were performed for NVG subjects.

Results

There was no statistical difference in the mean age and gender among the RVO, DR, and control groups (p>0.05). The mean level of platelet distribution width (PDW) was higher (p<0.001) in the RVO group (15.16±2.13fl) and DR group (16.17±1.66fl) when compared with the control group (13.77±2.99fl). The mean plateletcrit (PCT) value of the RVO group (0.229±0.063%) was also higher (p = 0.049) than the control group (0.199±0.045). In the DR group, mean platelet volume (MPV) value (10.72±1.57fl) was significantly higher (p = 0.002) than the control group (9.75±0.89fl). A similar trend was observed when platelet parameters were compared among the 3 groups with respect to age. The mean level of PDW was significantly higher (p<0.001) in the DR group (16.17±1.66fl) compared with the DM group (13.80±3.32fl). Stepwise multiple logistic regression analysis revealed that PDW (OR = 1.44, 95%CI = 1.149–1.805, p = 0.002) and MPV (OR = 1.503, 95%CI = 1.031–2.192, p = 0.034) were associated with the DR group, PDW (OR = 1.207, 95%CI = 1.010–1.443, p = 0.039) and PCT (OR = 1.663, 95%CI = 1.870–2.654, p = 0.036) were associated with the RVO group.

Conclusion

Our results suggest that increased PDW and MPV are associated with the NVG secondary to DR group, elevated PDW and PCT are associated with the RVO group. It indicates that platelets might be an important factor in the onset and/or development of NVG.

The era of anti-vascular endothelial growth factor (VEGF) drugs in ophthalmology, VEGF and anti-VEGF therapy

Angiogenesis is a clue process for tissue development and function, both in normal and pathological conditions. This process is regulated by multiple molecular systems. One of the most potent is vascular endothelial growth factor (VEGF) and its receptor (VEGFR) system. Members of this family are involved in new vessel formation in embryogenesis and maturation, as well as in reparative or pathological reactions in later stages. They play a substantial role in regeneration, inflammation, wound healing, as well as in cancer pathology. Nowadays it is possible to modulate VEGF-VEGFR interactions in many pathological conditions using anti-VEGF therapy. This therapy has already achieved a grounded position in the management of rheumatological disorders, tumour progression, and metastasis. Such drugs as bevacizumab, ranibizumab, aflibercept, and pegaptanib have also proven to be very effective in the treatment of several ocular diseases, such as age-related macular degeneration (AMD), macular oedema, or proliferative retinopathies and iris neovascularisation. The indications for the application of this therapy in ophthalmology are becoming wider and wider. It may also be used for corneal pathologies and in anti-glaucoma procedures.

Conjunctival Microangiopathy in a Patient with Neovascular Glaucoma

Purpose

To report a case of conjunctival microangiopathy secondary to diabetes presenting as a red eye 5 years after glaucoma implant surgery for neovascular glaucoma.

Materials and Methods

A 52-year-old Tongan male with a past history of neovascular glaucoma secondary to proliferative diabetic retinopathy underwent slitlamp examination and color photography of the anterior and posterior segment, in addition to anterior segment fluorescein angiography.

Results

The conjunctival venules perilimbally demonstrated tortuosity and dilation (saccular, fusiform and tricornuate). Capillaries were tortuous, with sparse microaneurysm formation, and arterioles were attenuated. Anterior segment fluorescein angiography showed generalized iris ischemia, extensive perilimbal microvascular degenerative changes and leakage of fluorescein into the anterior chamber. We are unaware of previous reports in the literature on conjunctival microangiopathy secondary to diabetes presenting as a red eye.

Conclusions

We hypothesized that the clinical features in our case may have been modified by a combination of postoperative wound healing and degenerative vascular remodeling, in addition to microvascular alterations secondary to both diabetes and consequent ocular ischemia, which may have played a role.