Vitreous levels of interleukine-8 and monocyte chemoattractant protein-1 in macular oedema with branch retinal vein occlusion

The protective effect of anti-VEGF-A/Ang-2 bispecific antibody on retinal vein occlusion model mice

(233/250) Retinal vein occlusion (RVO) causes macular edema and retinal ischemia resulting in visual field and vision loss. A bispecific antibody that blocks VEGF-A and angiopoietin-2 (Ang-2) has been recently launched and applied clinically to treat macular edema, but the role of Ang-2 in the pathogenesis of RVO is still unclear. In this study, we investigated the effects of the anti-VEGF-A/anti-Ang-2 bispecific antibody (BsAb) in a murine RVO model. By using RVO model mice, the expression of Ang-2 gene and protein was examined in the retina through real-time qPCR and Western blotting, respectively. A significant increase in Ang-2 was detected 1 day after occlusion. Immediately after occlusion, control IgG 400 μg/mL, anti-VEGF-A antibody 200 μg/mL, anti-Ang-2 antibody 200 μg/mL, and BsAb 400 μg/mL were intravitreally administered at 2 μL. Visual function was examined using electroretinograms, and apoptosis was examined using TUNEL staining. Interestingly, BsAb partially suppressed the decrease in amplitude of a and b waves compared to control IgG. Anti-Ang-2 antibody and BsAb reduced apoptosis-positive cells 1 day after occlusion. Comprehensive gene expression profiles were also examined using RNA sequencing analysis. RNA sequencing analysis of the retinal tissues showed that BsAb suppressed expression of gene groups associated with inflammatory response and vascular development compared to anti-VEGF-A antibody. Taken together, higher expression of Ang-2 contributes to the pathophysiology of RVO, providing a possible mechanism for the efficacy of BsAb in suppressing retinal dysfunction in RVO.

Efficacy of single-dose intravitreal dexamethasone implantation for retinal vein occlusion patients with refractory macular edema: A systematic review and meta-analysis

Purpose: To assess the functional and anatomical consequences of single-dose dexamethasone (DEX) implants for the treatment of refractory macular edema (ME) secondary to retinal vein occlusion (RVO) after anti-vascular endothelial growth factor agents.

Methods: A literature search of studies on switching therapy to DEX implants from anti-VEGF agents in refractory RVO patients was performed with five electronic databases (PubMed, Embase, Web of Science, MEDLINE, and Cochrane Library) prior to January 2022. The main outcomes included best-corrected visual acuity (BCVA) and central macular thickness (CMT) changes at different follow-up endpoints from baseline. All analyses were performed using Stata version 15.0.

Results: The final analysis included four eligible studies with a total of 99 patients. After single-dose DEX implant application, BCVA improved significantly at 2, 3, and 6 months with an average gain of −0.23 logarithm of the minimum angle of resolution (logMAR) (p = 0.004), −0.20 logMAR (p = 0.027), and -0.09 logMAR (p = 0.021), respectively. Mean CMT reduction was also significant from baseline to 2 months (-241.89 μm, p < 0.001), 3 months (−222.61 μm, p < 0.001), and 6 months (−90.49 μm, p < 0.001). No serious adverse events were observed in any of the included studies.

Conclusion: This meta-analysis showed that RVO patients with refractory ME could benefit significantly from switching therapy to DEX implantation, with efficacy lasting 6 months after a single-dose application. Intravitreal DEX implantation is a safe and effective option for refractory cases.

Changes in Tears Monocyte Chemoattractant Protein-1 Level After External Dacryocystorhinostomy in Primary Acquired Nasolacrimal Duct Obstruction

BACKGROUND

The authors aimed to define tears monocyte chemoattractant protein-1 (MCP-1) changes after external dacryocystorhinostomy surgery.

MATERIALS AND METHODS

Tears samples were collected with a Schirmer strip and stored in Eppendorf tubes at -80°C. At the end of the study, the papers were cut into small pieces and incubated with phosphate-buffered saline solution. Monocyte chemoattractant protein-1 levels were determined by using an enzyme-linked immunosorbent assays kit.

RESULTS

The MCP-1 levels were 498.66±101.35, 576.40±149.78, 422.53±85.94, and 436.96±81.38 ng/L before surgery, in the first week, the first, and third months after surgery, respectively. Its level significantly increased in the first week compared with the preoperative level ( P <0.001). There was a prominent decrease in the postoperative first month ( P <0.001). In the third postoperative month, the mean MCP-1 level was not significantly increased compared with the postoperative first month ( P =0.196).

CONCLUSION

The tears MCP-1 level was significantly decreased after external dacryocystorhinostomy surgery.

A Review of Intraocular Biomolecules in Retinal Vein Occlusion: Toward Potential Biomarkers for Companion Diagnostics

Retinal vein occlusion (RVO) is one of the most common retinal vascular diseases. The pathogenesis of RVO is multifactorial and involves a complex interplay among a variety of vascular and inflammatory mediators. Many cytokines, chemokines, growth factors, and cell adhesion molecules have been reported to be implicated. Treatments for RVO are directed at the management of underlying risk factors and vision-threatening complications, including macula edema (ME) and neovascularization. Intravitreal anti-VEGF agents are currently considered as the first-line treatment for ME secondary to RVO (RVO-ME), but a substantial proportion of patients responded insufficiently to anti-VEGF agents. Since RVO-ME refractory to anti-VEGF agents generally responds to corticosteroids and its visual outcome is negatively correlated to disease duration, prediction of treatment response at baseline in RVO-ME may significantly improve both cost-effectiveness and visual prognosis. Several bioactive molecules in the aqueous humor were found to be associated with disease status in RVO. This review aims to present a comprehensive review of intraocular biomolecules reported in RVO, including VEGF, IL-6, IL-8, MCP-1, sICAM-1, IL-12, IL-13, sVEGFR-1, sVEGFR-2, PDGF-AA, etc., highlighting their association with disease severity and/or phenotype, and their potential roles in prognostic prediction and treatment selection. Some of these molecules may serve as biomarkers for aqueous humor-based companion diagnostics for the treatment of RVO in the future.

The correlation between cytokine levels in the aqueous humor and the prognostic value of anti-vascular endothelial growth factor therapy for treating macular edema resulting from retinal vein occlusion

PURPOSE

To determine the correlation between aqueous humor cytokine levels and the prognostic value of anti-vascular endothelial growth factor (VEGF) therapy for treating macular edema resulting from retinal vein occlusion (RVO-ME).

METHODS

This prospective study included 47 RVO-ME and 32 senile cataract cases. Aqueous humor collection was performed in patients with RVO-ME before intravitreal injection of ranibizumab and in patients before cataract surgery. VEGF, monocyte chemotactic protein 1 (MCP-1), interleukin (IL)-8, IL-6, basic fibroblast growth factor (b-FGF), and tumor necrosis factor-α (TNF-α) levels were measured in the aqueous humor. Central retinal thickness (CRT) was measured before ranibizumab treatment and during each follow-up visit. The recovery rate following ranibizumab treatment was calculated as (CRT_BT-CRT_AT1W)/CRT_BT, in which CRT_BT was the CRT measured before treatment and CRT_AT1W was measured 1 week after treatment. The recurrence time of RVO-ME was recorded.

RESULTS

VEGF, MCP-1, IL-8, and IL-6 levels in the aqueous humor of patients with RVO-ME were significantly higher compared with control and were positively correlated with the CRT_BT. Ranibizumab significantly reduced CRT, and VEGF levels positively correlated with the recovery rate. The mean recurrence time of RVO-ME was 43.5 days. IL-6 levels negatively correlated with the recurrence time of ME.

CONCLUSION

VEGF, MCP-1, IL-8, and IL-6 levels were significantly increased in patients with RVO-ME and were positively correlated with ME. Higher VEGF levels were indicative of CRT recovery, and higher IL-6 levels were indicative of ME recurrence after ranibizumab treatment.

HIF Inhibition Therapy in Ocular Diseases

The uncontrolled growth of blood vessels is a major pathological factor in human eye diseases that can result in blindness. This effect is termed ocular neovascularization and is seen in diabetic retinopathy, age-related macular degeneration, glaucoma and retinopathy of prematurity. Current treatments for these diseases include laser photocoagulation, topical injection of corticosteroids, intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents and vitreoretinal surgery. Although strategies to inhibit VEGF have proved to be dramatically successful in some clinical studies, there remains the possibility of significant adverse effects regarding the blockade of crucial physiological roles of VEGF and the invasive nature of the treatments. Moreover, it is evident that other pro-angiogenic factors also play important roles in the development of these diseases, as seen in cases in which anti-VEGF therapies have failed. Therefore, new types of effective treatments are required. In this review, we discuss a promising strategy for the treatment of ocular neovascular diseases, i.e., the inhibition of hypoxia-inducible factor (HIF), a master regulator of angiogenesis. We also summarize promising recently investigated HIF inhibitors as treatments for ocular diseases. This review will facilitate more comprehensive approaches to understanding the protective aspects of HIF inhibition in the prevention of ocular diseases.

Changes in Aqueous and Vitreous Inflammatory Cytokine Levels in Retinal Vein Occlusion: A Systematic Review and Meta-analysis

Purpose:

Evidence suggests that inflammatory cytokines not only play a role in the pathogenesis of retinal vein occlusion (RVO) but also may be useful as biomarkers to predict disease severity and response to treatment. We aimed to quantitatively summarize data on inflammatory cytokines associated with RVO.

Methods:

A systematic search of peer-reviewed English-language articles was performed without year limitation up to August 19, 2019. Studies were included if they provided data on aqueous or vitreous cytokine concentrations in patients with RVO. Data were extracted from 116 studies that encompassed 3242 study eyes with RVO and 1402 control eyes. Effect sizes were generated as standardized mean differences (SMDs) of cytokine concentrations between patients with RVO vs controls.

Results:

Among the 4644 eyes in 116 studies, aqueous and vitreous concentrations (SMD, 95% CI, and P value) of interleukin (IL)-6 (aqueous: 1.23, 0.65 to 1.81, P < .001 vitreous: 0.70, 0.49 to 0.90, P < .001), IL-8 (aqueous: 1.11, 0.73 to 1.49, P < .001; vitreous: 1.19, 0.73 to 1.65, P < .001), monocyte chemoattractant protein 1(aqueous: 1.22, 0.72 to 1.72, P < .001; vitreous 1.42, 0.92 to 1.91, P < .001), vascular endothelial growth factor (VEGF) (aqueous: 1.52, 1.09 to 1.94, P < .001; vitreous: 0.99, 0.78 to 1.21, P < .001) were significantly higher in patients with RVO than in healthy controls. Only aqueous concentrations of IL-10 (0.81, 0.45 to 1.18, P < .001), angiopoietin 4 (1.96, 0.92 to 3.00, P < .001), and platelet-derived growth factor (PDGF)-AA (0.82, 0.35 to 1.30, P < .001) were significantly higher in patients with RVO than in healthy controls. Only the vitreous concentration of soluble intercellular adhesion molecule-1 (sICAM-1) (1.23, 0.83 to 1.63, P < .001) was significantly higher in patients with RVO. No differences, failed sensitivity analyses, or insufficient data were found between patients with RVO and healthy controls for the concentrations of the remaining cytokines.

Conclusions:

Several cytokines in addition to VEGF have the potential to be useful biomarkers and therapeutic targets in RVO.

Mo-derived perivascular macrophage recruitment protects against endothelial cell death in retinal vein occlusion

Background

To decipher the role of monocyte-derived macrophages (Mφs) in vascular remodeling of the occluded vein following experimental branch retinal vein occlusion (BRVO).

Methods

The inflammation induced by laser-induced BRVO on mice retina was evaluated at different time points by RT-PCR looking at inflammatory markers mRNA level expression, Icam-1, Cd11b, F4/80, Ccl2, and Ccr2 and by quantification of Iba1-positive macrophage (Mφ) density on Iba1-stained retinal flatmount. Repeated intraperitoneal EdU injection combined with liposome clodronate-induced monocyte (Mo) depletion in wildtype mice was used to differentiate Mo-derived Mφs from resident Mφs. Liposome clodronate Mo-depleted wildtype mice and Ccr2-deficient mice were used to evaluate the role of all CCR2⁺ and CCR2^neg Mo-derived Mφs on EC apoptosis in the occluded vein.

Results

cd11b, ICAM-1, F4/80, Ccl2, and Ccr2 mRNA expression were increased 1, 3, and 7 days after vein occlusion. The number of parenchymal (parMφs) and perivascular (vasMφs) macrophages was increased 3 and 7 days after BRVO. The systemic depletion of all circulating Mos decreased significantly the BRVO-induced parMφs and vasMφs macrophage accumulation, while the deletion of CCR2⁺-inflammatory Mo only diminished the accumulation of parMφs, but not vasMφs. Finally, apoptotic ECs of the vein were more numerous in fully depleted, liposome clodronate-treated mice, than in Ccr2^−/− mice that only lack the recruitment of CCR2⁺ inflammatory Mos.

Conclusions

BRVO triggers the recruitment of blood-derived parMφs and vasMφs. Interestingly, vasMφs accumulation was independent of CCR2. The observation that the inhibition of the recruitment of all infiltrating Mφs increases the vein EC apoptosis, while CCR2 deficiency does not, demonstrates that CCR2^neg Mo-derived vasMφs protect the ECs against apoptosis in the occluded vein.

Comprehensive analysis of vitreous chemokines involved in ischemic retinal vein occlusion

PURPOSE

To investigate vitreous levels of chemokines in eyes with ischemic retinal vein occlusion (RVO).

METHODS

The vitreous humor was collected at the start of 23-gauge pars plana vitrectomy from patients with ischemic RVO and patients with idiopathic preretinal membranes (PRMs) and idiopathic macular holes (IMHs). The levels of 40 different chemokines were measured using magnetic color-bead-based multiplex assay. The chi-square test was performed for clinical variables such as sex, and the Mann-Whitney U test was performed to evaluate the differences in the chemokine levels between the RVO group and the control group.

RESULTS

Vitreous humor was collected from 20 controls and 25 subjects with ischemic RVO. C-C motif ligand 17 (CCL17) was unmeasurable in more than 70% of the samples. The levels of 29 of 39 chemokines were statistically significantly elevated in the RVO group compared with the control group, including CCL21, C-X-C motif ligand (CXCL) 13, CCL27, CCL24, CX3CL1, CXCL6, interferon-gamma (IFN-γ), interleukin (IL) 1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-16, CXCL10, CXCL11, CCL8, CCL7, CCL13, CCL22, macrophage migration inhibitory factor (MIF), CXCL9, CCL3, CCL15, CCL20, CCL19, CCL23, CCL25, and tumor necrosis factor-alpha (TNF-α). Among the 29 elevated chemokines, we found that the levels of three chemokines (IL-8, CXCL9, and TNF-α) showed a more than six-fold increase in the RVO eyes versus controls, and CXCL9 expression showed the greatest change of all tested chemokines.

CONCLUSIONS

Dozens of chemokines were found to be elevated in the vitreous of RVO eyes complicated with vitreous hemorrhage, suggesting that inflammation is severe in the ischemic retina. The knowledge of specific upregulation of chemokines in ischemic RVO could allow more targeted future therapies.

Dexamethasone intravitreal implant downregulates PDGFR-α and upregulates caveolin-1 in experimental branch retinal vein occlusion

A dexamethasone (DEX) intravitreal implant (OZURDEX) provides an effective treatment of inflammation secondary to branch retinal vein occlusion (BRVO). Retinal proteome changes which mediate the beneficial effects of the implant remain poorly understood. To study retinal proteome changes in BRVO following an intervention with a DEX implant this study combined an experimental model of BRVO with proteomic techniques. In eight Danish Landrace pigs experimental BRVO was induced in both eyes using argon laser. After inducing BRVO a DEX implant was injected into the right eye of each animal while the left control eye was given an identical injection without an implant. Fifteen days after BRVO and DEX implant intervention the retinas were excised and analyzed with tandem mass tag based mass spectrometry. A total of 26 significantly changed proteins were identified. DEX intervention reduced the retinal levels of platelet-derived growth factor receptor-α (PDGFR-α) and vascular endothelial growth factor receptor 2 (VEGFR-2). DEX treatment resulted in increased levels of caveolin-1, peptidyl-prolyl cis-trans isomerase FKBP5 and transgelin. Changes in PDGFR-α and caveolin-1 were confirmed with immunohistochemistry. In BRVO treated with the DEX implant a strong reaction for caveolin-1 was observed in the innermost retinal layers. DEX implant intervention may inhibit PDGF signaling by decreasing the retinal level of PDGFR-α while an increased content of caveolin-1 may help maintain the integrity of the blood-retinal barrier.

Dexamethasone Intravitreal Implant Rescue Treatment for Bevacizumab Refractory Macular Edema Secondary to Branch Retinal Vein Occlusion

PURPOSE

To evaluate the prognostic factors and outcomes of dexamethasone intravitreal implant (DEX implant) for intravitreal bevacizumab refractory macular edema secondary to branch retinal vein occlusion (BRVO).

METHODS

This was a retrospective, interventional case series. Medical records were reviewed, and a total of 38 eyes that were treated with DEX implant for macular edema secondary to BRVO that did not respond to at least two consecutive intravitreal bevacizumab injections (IBIs) were included. Best-corrected visual acuity (BCVA), central subfield macular thickness, and central subfoveal choroidal thickness were evaluated at baseline, 2 months, and 6 months after DEX implantation.

RESULTS

Patients had undergone an average of 6.32 ± 4.66 prior IBI treatments. The average BCVA improved from 0.53 ± 0.26 to 0.41 ± 0.25 and 0.44 ± 0.23 logarithm of the minimal angle of resolution (logMAR) at 2 and 6 months, respectively (p < 0.001). The average central subfield macular thickness was 504.00 ± 121.54 µm at baseline and changed to 293.21 ± 74.17 µm and 427.28 ± 119.57 µm at 2 and 6 months, respectively (p < 0.001 and p = 0.002). Average central subfoveal choroidal thickness was 237.46 ± 92.21 µm at baseline and changed to 204.75 ± 74.74 µm and 226.86 ± 90.77 µm at 2 and 6 months, respectively (p < 0.001 and p = 0.455). Twenty-two eyes (58%) gained ≥0.1 logMAR at 2 months, while 16 eyes showed no improvement. Low BCVA at symptom presentation, low baseline BCVA, and shorter duration of macular edema were correlated with increased BCVA after treatment.

CONCLUSIONS

The DEX implant improves functional and anatomical outcomes for up to 6 months in about half of the patients treated with IBI refractory macular edema secondary to BRVO, particularly in patients with low initial and baseline BCVA.

Natural Short-term Course of Recurrent Macular Edema Following Intravitreal Bevacizumab Therapy in Branch Retinal Vein Occlusion

Purpose

To evaluate the 3-month natural course of recurrent macular edema secondary to branch retinal vein occlusion (BRVO) treated with intravitreal bevacizumab.

Methods

This retrospective, observational study included 36 eyes with macular edema secondary to BRVO. All patients were initially treated with intravitreal bevacizumab for macular edema. Recurrence of macular edema was either not treated (untreated group) or treated with a single intravitreal bevacizumab injection (treated group). Central foveal thickness (CFT) and best-corrected visual acuity (BCVA) were compared at the time of recurrence and 3 months later.

Results

At the time of recurrence, the mean CFT and logarithm of the minimum angle of resolution BCVA were 484.9 ± 124.1 µm and 0.58 ± 0.26 in the untreated group (n = 19) and 456.3 ± 126.8 µm and 0.51 ± 0.21 in the treated group (n = 17), respectively. Three months later, the mean CFT and BCVA had changed to 493.7 ± 123.9 µm and 0.62 ± 0.29 in the untreated group and 294.7 ± 104.4 µm and 0.40 ± 0.24 in the treated group, respectively. The differences in CFT and BCVA between the two time points were not significant in the untreated group (p = 0.106 and p = 0.687, respectively), whereas statistically significant differences were noted in the treated group (p = 0.002 and p < 0.001, respectively).

Conclusions

Unlike the first episode of macular edema following BRVO, recurrent macular edema following intravitreal bevacizumab therapy did not spontaneously resolve, suggesting the potential benefit of prompt treatment.

Combination of Bevacizumab and NGF Reduces the Risk of Diabetic Retinopathy

Accumulated evidences support diabetic retinopathy is caused by functional and structural alterations in both the microvascular and neuroglial compartments. Here, we explored any beneficial effects of combination of Bevacizumab and NGF to prevent diabetic retinopathy. STZ-induced diabetic rats were randomly grouped into three groups: sham, Bevacizumab and combination group (Bevacizumab + NGF). End of the treatment, vascular abnormality was evaluated by FITC-dextran. Inflammation and angiogenesis factors were also investigated by real-time PCR and western blot. Our results showed both Bevacizumab and the combination could dramatically reduce abnormal vascular permeability and limit the inflammatory and angiogenesis in 6-week diabetic rats. However, the combination indicated better preventive effects in 12-week diabetic rats compared with Bevacizumab alone. Our findings suggest that the combination of Bevacizumab with NGF may be a new method for the preventive intervention of diabetic retinopathy.

Short-term efficacy of intravitreal triamcinolone acetonide for macular edema secondary to retinal vein occlusion that is refractory to intravitreal bevacizumab

AIMS

To evaluate the 1-month efficacy of intravitreal triamcinolone acetonide (TA) in treating macular edema secondary to retinal vein occlusion (RVO) that was refractory to intravitreal bevacizumab.

MATERIALS AND METHODS

This retrospective, observational study included 23 eyes from 23 patients with macular edema secondary to RVO. Macular edema that did not respond to two or more consecutive intravitreal bevacizumab injections was treated with intravitreal TA. Central foveal thickness (CFT) and best-corrected visual acuity (BCVA) were compared before and one month after TA injection.

RESULTS

Fifteen eyes were diagnosed with central RVO, and eight eyes were diagnosed with branch RVO. All patients were previously treated with 2.4 ± 0.6 intravitreal bevacizumab injections. The TA injection was performed, on average, 5.8 ± 1.4 weeks after the last bevacizumab injection. The CFT before TA injection was 516.6 ± 112.4 μm and significantly decreased to 402.3 ± 159.7 μm after TA therapy (P < 0.001). The logarithm of the minimal angle of resolution BCVA was 0.72 ± 0.34 before TA therapy and was not significantly improved by the treatment (0.67 ± 0.35, P = 0.119), despite a decrease in CFT. However, seven eyes (30.4%) had a BCVA gain of one or more lines.

CONCLUSIONS

Intravitreal TA therapy was beneficial in some patients with macular edema secondary to RVO that was refractory to intravitreal bevacizumab therapy. This study suggests that intravitreal TA should be considered as a treatment option for refractory macular edema.

IL-8 and VEGFR-2 polymorphisms modulate long-term functional response to intravitreal ranibizumab in exudative age-related macular degeneration

AIM

To investigate possible associations between VEGFR-2 and IL-8 gene SNPs and 1-year response to intravitreal ranibizumab for exudative age-related macular degeneration.

MATERIALS & METHODS

Sixty-four eyes underwent a loading phase of three monthly intravitreal injections of ranibizumab 0.5 mg/0.05 ml followed by Pro Re Nata retreatment. VEGFR-2 rs2071559 (-604 A/G) and IL-8 rs4073 (-251 A/T) were analyzed.

RESULTS

Ranibizumab was significantly more effective as measured by visual acuity in patients harboring the IL-8 rs4073 TT genotype (p = 0.045), whereas patients carrying the VEGFR-2 rs2071559 CC genotype revealed better functional response as measured by mean retinal sensitivity (p = 0.034).

CONCLUSION

IL-8 rs4073 and VEGFR-2 rs2071559 genotypes may represent important molecular determinants to modulate final outcomes in neovascular age-related macular degeneration patients.

Proteins involved in focal adhesion signaling pathways are differentially regulated in experimental branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is a common retinal vascular disease, but global protein changes following the condition remain largely unelucidated. To bring new insights into pathological processes and identify potential therapeutic targets, large-scale retinal protein changes following BRVO were studied by combining a porcine model of experimental BRVO with proteomic analysis by label-free liquid chromatography mass spectrometry. Among a total set of 1974 proteins, 52 significantly upregulated proteins and 10 significantly downregulated proteins were identified in retinas with BRVO after 15 days. Significantly upregulated proteins were involved in signaling pathways of focal adhesion via integrin and blood coagulation. Proteins involved in focal adhesion signaling included collagen α-2 chain, laminin subunit β-2, laminin subunit γ-1, lipocalin-7, nidogen-2, osteopontin, integrin-β, α-actinin-1, isoform 2 of α-actinin-1, talin-2 and filamin C. The identified proteins indicate that BRVO was associated with extracellular matrix remodeling processes. The present study identified focal adhesion signaling and ECM remodeling as important biological mechanisms to evaluate in the search for signaling pathways that promote neovascularisation and macular edema following BRVO.

Interleukin 8 promoter polymorphism predicts the initial response to bevacizumab treatment for exudative age-related macular degeneration

PURPOSE

To study the association of single-nucleotide polymorphisms of interleukin 8, vascular endothelial growth factor, erythropoietin, complement factor H, complement component C3, and LOC387715 genes with the response to bevacizumab treatment in exudative age-related macular degeneration.

METHODS

Clinical records, smoking history, optical coherence tomography, and angiographies of 96 bevacizumab-treated exudative age-related macular degeneration patients were analyzed retrospectively. Blood DNA was collected. Based on the disappearance of intra- or subretinal fluid in optical coherence tomography, patients were graded as responders, partial responders, or nonresponders after 3 initial treatment visits and a median time of 3.5 months.

RESULTS

Interleukin 8 promoter polymorphism -251A/T was significantly associated with persisting fluid in optical coherence tomography. The A allele was more frequent in nonresponders than in responders (P = 0.033). In multivariate modeling, the AA genotype of -251A/T (P = 0.043) and occult (P = 0.042) or predominantly classic (P = 0.040) lesions predicted poorer outcome. Visual acuity change was better in responders than in nonresponders (P = 0.006). Baseline lesion size (P = 0.006) and retinal cysts after the treatment (P < 0.001) correlated with less visual acuity gain.

CONCLUSION

The A allele and the homozygous AA genotype of interleukin 8 -251A/T were associated with anatomical nonresponse to bevacizumab treatment.

Proteomic analysis of aqueous humor from patients with branch retinal vein occlusion-induced macular edema

The mechanisms responsible for macular edema with branch retinal vein occlusion (BRVO) remain to be elucidated. It is known that the expression profile of certain proteins in the aqueous humor (AH) changes in some diseases. Accordingly, determining the expression of these AH proteins may aid in the understanding of their potential role in this pathogenesis. The aim of this study was to identify the possible mechanisms involved in the development of BRVO-induced macular edema. A proteomic analysis of the AH composition in the eyes of patients with BRVO was performed and compared with that in the eyes of patients with cataract (non-BRVO; controls). AH from 6 patients with macular edema due to BRVO and 6 patients with cataract (non-BRVO) was collected. A proteomic approach which included 2‑dimensional electrophoresis (2‑DE) coupled with mass spectrometry (MS) and bioinformatics analysis were used to identify AH proteins with altered expression in patients with macular edema due to BRVO compared with the controls. An enzyme‑linked immunosorbent assay was used to validate the proteomic results. The total protein concentration in the AH of patients with BRVO-induced macular edema was significantly greater than that of the controls. In the patients with BRVO, a total of 56 protein spots were significantly altered on the 2D gels. A total of 49 protein spots were identified by MS; many of these proteins have been implicated in angiogenesis, oxidative stress and collagen synthesis. In conclusion, the protein composition in AH differed significantly between the patients with BRVO and the controls. The identified proteins may be potential biomarkers for the development of macular edema due to BRVO and may play a role in the mechanisms responsible for it.

Soluble vascular endothelial growth factor receptor-2 and inflammatory factors in macular edema with branch retinal vein occlusion

PURPOSE

To investigate relationships among vitreous fluid levels of soluble vascular endothelial growth factor receptor-2 (sVEGFR-2), vascular endothelial growth factor (VEGF), and soluble intercellular adhesion molecule 1 (sICAM-1) in patients with branch retinal vein occlusion (BRVO) and macular edema or patients with idiopathic macular hole.

DESIGN

Retrospective case-control study.

METHODS

SETTING

Tokyo Women's Medical University and Eguchi Eye Hospital.

PATIENT POPULATION

Forty-nine Japanese patients who underwent unilateral vitrectomy (27 with BRVO and 22 with macular hole).

OBSERVATION PROCEDURES

Vitreous fluid samples were obtained during vitreoretinal surgery to measure the levels of sVEGFR-2, VEGF, and sICAM-1. Retinal ischemia was evaluated from capillary nonperfusion on fluorescein angiography. Macular edema was examined by optical coherence tomography.

MAIN OUTCOME MEASURES

Vitreous fluid levels of the 3 molecules and severity of macular edema.

RESULTS

BRVO patients had a significantly higher vitreous fluid level of sVEGFR-2 (median, 1670 pg/mL; interquartile range [IQL], 1205 to 2225 pg/mL) than macular hole patients (median, 1265 pg/mL; IQR, 731 to 1800 pg/mL; P = .017), as was the case for VEGF (median, 237 pg/mL; IQR, 42.2 to 1305 pg/mL; vs median, 15.6 pg/mL; IQR, 15.6 to 15.6 pg/mL; P < .001) and sICAM-1 (median, 10.1 ng/mL; IQR, 6.3 to 22.5 ng/mL; vs median, 4.1 ng/mL; IQR, 3.3 to 6.0 ng/mL; P < .001). In BRVO patients, there was a significant positive correlation between vitreous fluid levels of sVEGFR-2 or VEGF and sICAM-1, but not between sVEGFR-2 and VEGF. Vitreous fluid levels of all 3 molecules were correlated significantly the with severity of macular edema in BRVO patients.

CONCLUSIONS

sVEGFR-2 may induce an increase of vascular permeability together with or via sICAM-1, or both with and via sICAM-1, in BRVO patients with macular edema.