PENTRAXIN 3 AND OTHER INFLAMMATORY FACTORS IN CENTRAL RETINAL VEIN OCCLUSION AND MACULAR EDEMA

Integrated Assessment of OCT, Multimodal Imaging, and Cytokine Markers for Predicting Treatment Responses in Retinal Vein Occlusion Associated Macular Edema: A Comparative Review of Anti-VEGF and Steroid Therapies

Retinal vein occlusion (RVO) is a significant cause of vision loss, characterized by the occlusion of retinal veins, leading to conditions such as central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Macular edema (ME), a prevalent consequence of RVO, is the primary cause of vision impairment in affected patients. Anti-VEGF agents have become the standard treatment, showing efficacy in improving visual acuity (VA) and reducing ME. However, a subset of patients exhibit a suboptimal response to anti-VEGF therapy, necessitating alternative treatments. Corticosteroids, which address inflammatory pathways implicated in ME, have shown promise, particularly in cases resistant to anti-VEGF. This review aims to identify biomarkers that predict treatment response to corticosteroids in RVO-associated ME, utilizing multimodal imaging and cytokine assessments. Baseline imaging, including SD-OCT and OCT-A, is essential for evaluating biomarkers like hyperreflective foci (HRF), serous retinal detachment (SRF), and central retinal thickness (CRT). Elevated cytokine levels, such as IL-6 and MCP-1, correlate with ME severity and poor anti-VEGF response. Early identification of these biomarkers can guide timely transitions to corticosteroid therapy, potentially enhancing treatment outcomes. The practical conclusion of this review is that integrating biomarker assessment into clinical practice enables personalized treatment decisions, allowing for earlier and more effective management of RVO-associated ME by transitioning patients to corticosteroid therapy when anti-VEGF agents are insufficient. Advanced diagnostics and machine learning may further refine personalized treatment strategies, improving the management of RVO-associated ME.

Role of Novel Inflammatory Factors in Central Retinal Vein Occlusion with Macular Edema

Background and Objectives: To investigate associations among the aqueous humor levels of novel inflammatory factors, including FMS-related tyrosine kinase 3 ligand (Flt-3L), fractalkine, CXC chemokine ligand 16 (CXCL-16), and endocan-1; the severity of macular edema in central retinal vein occlusion (CRVO); and the prognosis of CRVO with macular edema after antivascular endothelial growth factor (VEGF) therapy. Materials and Methods: Aqueous humor was obtained during anti-VEGF treatment with intravitreal ranibizumab injection (IRI) in patients with CRVO and macular edema (n = 19) and during cataract surgery in patients with cataracts (controls, n = 20), and the levels of VEGF and novel inflammatory factors were measured. Macular edema was evaluated by central macular thickness (CMT) and neurosensory retinal thickness (TNeuro), and improvement was evaluated by calculating the percentage change in CMT and TNeuro from before to 1 month after IRI. Results: The levels of VEGF and the novel inflammatory factors were significantly higher in the CRVO group, and the levels of Flt-3L, CXCL-16, and endocan-1 were significantly correlated with each other and with the aqueous flare value. Baseline levels of Flt-3L, CXCL-16, and endocan-1 had a significantly negative correlation with the change in CMT, and the baseline level of CXCL-16 was significantly negatively correlated with the change in TNeuro. Conclusions: Relations among novel inflammatory factors should be further investigated. These findings may help improve understanding of macular edema in CRVO patients and aid the development of new treatments targeting novel inflammatory factors.

High Levels of C-Reactive Protein with Low Levels of Pentraxin 3 as Biomarkers for Central Serous Chorioretinopathy

Purpose

To investigate the association between the 2 acute phase proteins, C-reactive protein (CRP) and pentraxin 3 (PTX3) with central serous chorioretinopathy (CSCR), as PTX3 is a glucocorticoid-induced protein.

Design

Cross-sectional multicenter study.

Participants

Patients with CSCR compared with age- and sex-matched healthy participants.

Methods

Patients with CSCR from 3 centers in Europe were included in the study. The clinical form of CSCR was recorded. Blood samples from patients with CSCR and healthy participants were sampled, and high-sensitivity CRP and PTX3 levels were measured in the serum.

Main Outcome Measures

C-reactive protein and PTX3 serum level comparison between patients with CSCR with age- and sex-matched healthy participants.

Results

Although CRP levels were higher in patients with CSCR (n = 216) than in age- and sex-matched controls (n = 130) (2.2 ± 3.2 mg/l vs. 1.5 mg/l ± 1.4, respectively, P = 0.037), PTX3 levels were lower in patients with CSCR (10.5 ± 19.9 pg/ml vs. 87.4 ± 73.2 pg/ml, respectively, P < 0.001). There was no significant difference in CRP or PTX3 levels between patients with acute/recurrent and chronic CSCR.

Conclusions

In patients with CSCR, high CRP and low PTX3 levels suggest a form of low-grade systemic inflammation together with a lack of glucocorticoid pathway activation, raising new hypotheses on the pathophysiology of CSCR.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effects of Intravitreal Ranibizumab Injection to Treat Macular Edema due to Central Retinal Vein Occlusion on Choroidal Findings and Functional-Morphological Parameters

INTRODUCTION

Little research has examined the effects of anti-vascular endothelial growth factor therapy on subfoveal choroidal thickness (SCT), choroidal blood flow, aqueous flare, and humor levels of growth and inflammatory factors in patients with macular edema due to central retinal vein occlusion (CRVO).

METHODS

In 58 patients with macular edema due to CRVO treated by intravitreal ranibizumab injection (IRI), we retrospectively assessed best-corrected visual acuity (BCVA, assessed as the logarithm of the minimum angle of resolution [logMAR]), 8 aqueous factors (by suspension array), mean blur rate (MBR; estimated by laser speckle flowgraphy as a measure of choroidal blood flow), aqueous flare (with a laser flare meter), and SCT and central macular thickness (CMT; by optical coherence tomography).

RESULTS

After 4 weeks, IRI resulted in a significant improvement in BCVA and CMT and a significant reduction in SCT, choroidal MBR, and aqueous flare. SCT was significantly positively correlated with placental growth factor and significantly negatively correlated with platelet-derived growth factor-AA, and change in SCT was significantly negatively correlated with change in BCVA (logMAR). Aqueous flare was significantly negatively correlated with SCT.

CONCLUSION

Growth and inflammatory factors may be associated with SCT, and changes in SCT may be associated with changes in BCVA after IRI to treat macular edema due to CRVO.

Upregulation of retinal VEGF and connexin 43 in murine nonarteritic anterior ischemic optic neuropathy induced with 577 nm laser

Nonarteritic anterior ischemic optic neuropathy (NAION) is a common acute optic neuropathy and cause of irreversible vision loss in those older than 50 years of age. There is currently no effective treatment for NAION and the biological mechanisms leading to neuronal loss are not fully understood. Promising novel targets include glial cells activation and intercellular communication mediated by molecules such as gap junction protein Connexin 43 (Cx43), which modulate neuronal fate in central nervous system disorders. In this study, we investigated retinal glial changes and neuronal loss following a novel NAION animal model using a 577 nm yellow laser. We induced unilateral photochemical thrombosis using rose bengal at the optic nerve head vasculature in adult C57BL/6 mice using a 577 nm laser and performed morphometric analysis of the retinal structure using serial in vivo optical coherence tomography (OCT) and histology for glial and neuronal markers. One day after experimental NAION, in acute phase, OCT imaging revealed peripapillary thickening of the retinal ganglion cell complex (GCC, baseline: 79.5 ± 1.0 μm, n = 8; NAION: 93.0 ± 2.5 μm, n = 8, P < 0.01) and total retina (baseline: 202.9 ± 2.4 μm, n = 8; NAION: 228.1 ± 6.8 μm, n = 8, P < 0.01). Twenty-one days after ischemia, at a chronic phase, there was significant GCC thinning (baseline 78.3 ± 2.1 μm, n = 6; NAION: 72.2 ± 1.9 μm, n = 5, P < 0.05), mimicking human disease. Examination of molecular changes in the retina one day after ischemia revealed that NAION induced a significant increase in retinal VEGF levels (control: 2319 ± 195, n = 5; NAION: 4549 ± 683 gray mean value, n = 5, P < 0.05), which highly correlated with retinal thickness (r = 0.89, P < 0.05). NAION also led to significant increase in mRNA level for Cx43 (Gj1a) at day 1 (control: 1.291 ± 0.38; NAION: 3.360 ± 0.58 puncta/mm2, n = 5, P < 0.05), but not of glial fibrillary acidic protein (Gfap) at the same time (control: 2,800 ± 0.59; NAION: 4,690 ± 0.90 puncta/mm2 n = 5, P = 0.19). Retinal ganglion cell loss at day 21 was confirmed by a 30% decrease in Brn3a+ cells (control: 2,844 ± 235; NAION: 2,001 ± 264 cells/mm2, n = 4, P < 0.05). We described a novel protocol of NAION induction by photochemical thrombosis using a 577 nm laser, leading to retinal edema and VEGF increase at day 1 and RGCs loss at day 21 after injury, consistent with the pathophysiology of human NAION. Early changes in glial cells intercommunication revealed by increased Cx43+ gap junctions are consistent with a retinal glial role in mediating cell-to-cell signaling after an ischemic insult. Our study demonstrates an early glial response in a novel NAION animal model and reveals glial intercommunication molecules such as Cx43 as a promising therapeutic target in acute NAION.

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.

Retinal vein occlusion: drug targets and therapeutic implications

INTRODUCTION

The pathogenesis of retinal vein occlusion (RVO) is extremely complex and includes several mediators. These mediators represent potential drug targets that can be used in the development of intravitreal drugs.

AREAS COVERED

PubMed/MEDLINE databases were accessed between April-May 2021 to find the most relevant scientific papers regarding drug targets and therapeutic implications in RVO, focusing on current therapeutic options and potential cornerstones of future advances in treatment.

EXPERT OPINION

Before the introduction of intravitreal therapies, the visual outcome following a diagnosis of RVO was extremely poor. Anti-VEGF and corticosteroid treatments have radically changed RVO prognosis, helping to preserve patients' visual function and their quality of life. According to current clinical data, anti-VEGF and corticosteroid drugs are associated with both pros and cons; the present recommendation is to employ anti-VEGF molecules as a first-line treatment. Advances in our understanding of the biomolecular characteristics of RVO offer a solid basis for the development of new therapeutic targets and treatments.

Hypoxia-induced inflammation: Profiling the first 24-hour posthypoxic plasma and central nervous system changes

Central nervous system and visual dysfunction is an unfortunate consequence of systemic hypoxia in the setting of cardiopulmonary disease, including infection with SARS-CoV-2, high-altitude cerebral edema and retinopathy and other conditions. Hypoxia-induced inflammatory signaling may lead to retinal inflammation, gliosis and visual disturbances. We investigated the consequences of systemic hypoxia using serial retinal optical coherence tomography and by assessing the earliest changes within 24h after hypoxia by measuring a proteomics panel of 39 cytokines, chemokines and growth factors in the plasma and retina, as well as using retinal histology. We induced severe systemic hypoxia in adult C57BL/6 mice using a hypoxia chamber (10% O2) for 1 week and rapidly assessed measurements within 1h compared with 18h after hypoxia. Optical coherence tomography revealed retinal tissue edema at 18h after hypoxia. Hierarchical clustering of plasma and retinal immune molecules revealed obvious segregation of the 1h posthypoxia group away from that of controls. One hour after hypoxia, there were 10 significantly increased molecules in plasma and 4 in retina. Interleukin-1β and vascular endothelial growth factor were increased in both tissues. Concomitantly, there was significantly increased aquaporin-4, decreased Kir4.1, and increased gliosis in retinal histology. In summary, the immediate posthypoxic period is characterized by molecular changes consistent with systemic and retinal inflammation and retinal glial changes important in water transport, leading to tissue edema. This posthypoxic inflammation rapidly improves within 24h, consistent with the typically mild and transient visual disturbance in hypoxia, such as in high-altitude retinopathy. Given hypoxia increases risk of vision loss, more studies in at-risk patients, such as plasma immune profiling and in vivo retinal imaging, are needed in order to identify novel diagnostic or prognostic biomarkers of visual impairment in systemic hypoxia.

Cytokines and Pathogenesis of Central Retinal Vein Occlusion

Central retinal vein occlusion (CRVO) causes macular edema and subsequent vision loss and is common in people with diseases such as arteriosclerosis and hypertension. Various treatments for CRVO-associated macular edema have been trialed, including laser photocoagulation, with unsatisfactory results. However, when the important pathogenic role of vascular endothelial growth factor (VEGF) in macular edema was identified, the treatment of CRVO was revolutionized by anti-VEGF therapy. However, despite the success of intraocular injection of anti-VEGF agents in many patients with CRVO, some patients continue to suffer from refractory or recurring edema. In addition, the expression of inflammatory cytokines increases over time, causing more severe inflammation and a condition that is increasingly resistant to anti-VEGF therapy. This indicates that the pathogenesis of macular edema in CRVO is more complex than originally thought and may involve factors or cytokines associated with inflammation and ischemia other than VEGF. CRVO is also associated with leukocyte abnormalities and a gradual reduction in retinal blood flow velocity, which increase the likelihood of it developing from the nonischemic type into the more severe ischemic type; in turn, this results in excessive VEGF expression and subsequent neovascular glaucoma. Here, we review the role of different factors and cytokines involved in CRVO pathogenesis and propose a mechanism that holds promise for the development of novel therapies.

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.

Anti-vascular endothelial growth factor agent reduces inflammation in macular edema with central retinal vein occlusion

Background

Correlations among the aqueous flare value (an indicator of inflammation), functional-morphologic parameters, and aqueous humor levels of growth factors/receptors and inflammatory factors/cytokines were investigated in patients with central retinal vein occlusion (CRVO) and macular edema who received intravitreal ranibizumab injection (IRI) and were followed for 6 months.

Methods

Aqueous humor levels of 11 cytokines or growth inflammatory/factors were measured in 20 CRVO patients with macular edema receiving IRI. Patients with recurrent macular edema were administered further IRI as needed. Aqueous humor levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor (sVEGFR), and other cytokines/inflammatory factors were measured by the suspension array method. Aqueous flare values were measured with a laser flare meter and macular edema was examined by optical coherence tomography.

Results

Compared with before treatment (baseline), the aqueous flare value showed a significant decrease at both 1 month and 6 months after IRI therapy. There were significant correlations between the aqueous flare value and the aqueous levels of sVEGFR-1, placental growth factor, monocyte chemoattractant protein 1, soluble intercellular adhesion molecule-1, interleukin (IL)-6, and IL-8. In addition, a significant correlation was noted between the change of the aqueous flare value and improvement of central macular thickness at 6 months after IRI, as well as a significant correlation between the change of the aqueous flare value and improvement of best-corrected visual acuity at 6 months.

Conclusions

These findings suggest that IRI reduces inflammation and that the aqueous flare value is influenced by inflammatory factors/cytokines. In addition, the change of the aqueous flare value may be an indicator of the long-term prognosis in CRVO patients receiving IRI therapy for macular edema.

IL-18 and S100A12 Are Upregulated in Experimental Central Retinal Vein Occlusion

Retinal vein occlusion (RVO) is a common retinal vascular disease. RVO may be complicated by pronounced ischemia that often leads to severe loss of visual function. The present work aimed at studying the retinal proteome of RVO complicated by ischemia. In six Danish Landrace pigs RVO was induced with argon laser in the right eye of each animal. As four retinal veins were occluded, the RVO best corresponded to a central retinal vein occlusion (CRVO). Left control eyes received a similar laser treatment without inducing occlusion. RVO and retinal ischemia were verified by angiography. The retinas were collected 15 days after RVO for proteomic analysis. RVO resulted in a downregulation of proteins involved in visual perception, including rhodopsin, transducin alpha chain, and peripherin-2. RVO also caused a downregulation of proteins involved in neurotransmitter transport, including glutamate decarboxylase 1 (GAD1), glutamate decarboxylase 2 (GAD2), and complexins 2⁻4. RVO lead to increased contents of proteins involved in inflammation, including interleukin-18 (IL-18), S100A12, and annexin A1 (ANXA1). Immunohistochemistry revealed a general retinal upregulation of IL-18 and ANXA1 while S100A12 was highly abundant in retinal ganglion cells in RVO. IL-18 and S100A12 are likely to be driving forces in the inflammatory response of RVO complicated by ischemia. Our findings also suggest that RVO results in compromised neurotransmission and a downregulation of proteins involved in visual perception.

Increased Fibrinogen to Albumin Ratio in Ischemic Retinal Vein Occlusions

Purpose

To demonstrate the relationship between ischemia and plasma fibrinogen and serum albumin levels in cases of retinal vein occlusion (RVO).

Methods

This study included 44 patients with central RVO (CRVO), 68 patients with branch RVO (BRVO), and 54 age- and sex-matched controls, for a total of 166 subjects. All of the subjects underwent full ophthalmologic examinations and complete physical examinations, including a detailed medical history and blood count, and biochemical parameters.

Results

The mean fibrinogen to albumin ratios were 92.5 ± 36.1 for the patients with CRVO, 84.5 ± 31.5 for the patients with BRVO, and 68.4 ± 12.2 for the control group. Overall, the patients with CRVO and patients with BRVO with ischemia had higher fibrinogen to albumin ratios and higher fibrinogen levels. Moreover, significant positive correlations were found between ischemia and the fibrinogen to albumin ratio (r = 0.732, p = 0.001) and the fibrinogen level (r = 0.669, p = 0.001).

Conclusions

The fibrinogen to albumin ratio is significantly associated with ischemic RVO. Instead of complicated and invasive methods, such as a retinal angiogram, the fibrinogen to albumin ratio could be a useful initial diagnostic test to predict ischemia in RVO.

Effect of intravitreal dexamethasone implant on intra-ocular cytokines and chemokines in eyes with retinal vein occlusion

PURPOSE

To investigate the influence of intravitreal dexamethasone implant on inflammatory and angiogenic cytokine levels in the aqueous of patients with retinal vein occlusion (RVO).

METHODS

Forty eyes of 40 consecutive patients with macular oedema (ME) due to branch and central retinal vein occlusion (BRVO/CRVO) were treated with an intravitreal dexamethasone implant (Ozurdex^® ) at baseline and evaluated until month 6. Retreatment was performed in case of recurrent ME earliest 4 months after the baseline treatment. Aqueous humour samples were taken at baseline, months 1, 3, 6 and at the time of each retreatment. Concentrations of 29 different cytokines were measured by Luminex^® bead assays. The control group comprised healthy patients undergoing cataract surgery.

RESULTS

At baseline concentrations of interleukin (IL)-8, angiopoietin (ANG)-2 and intercellular adhesion molecule (ICAM)-1 were highly elevated in patients with CRVO compared with controls (p = 0.006; p = 0.02; p = 0.03). Vascular endothelial growth factor (VEGF) concentrations were upregulated in patients with BRVO and CRVO (p = 0.003; p = 0.001). Retreatment with a dexamethasone implant was necessary after 4 months in 14/8 (BRVO/CRVO) patients, 5 months in 5/3 patients and 6 months in one patient (BRVO). After the initial treatment, macrophage chemo-attractant protein (MCP)-1 and IL17-E concentrations decreased in BRVO (p < 0.001; p = 0.01) and MCP-1 and IL1-α in CRVO (p = 0.01; p = 0.003). Vascular endothelial growth factor (VEGF) concentrations did not change during treatment in either group (p = 0.3). A mixed-effect model showed that cytokine concentrations positively correlated with central retinal thickness changes.

CONCLUSIONS

Intravitreal dexamethasone treatment resulted in alterations in the concentrations of pro-inflammatory cytokines MCP-1 and IL17-E in patients with BRVO and MCP-1 and IL1-α in patients with CRVO. These data highlight the important role of inflammatory mediators involved in ME due to RVO.

Ranibizumab versus aflibercept for macular edema due to central retinal vein occlusion: 18-month results in real-life data

PURPOSE

The objective of this study was to compare the anatomical and functional outcomes of ranibizumab versus aflibercept for the treatment of macular edema due to central retinal vein occlusion (CRVO) in routine clinical practice.

METHODS

Participants in this observational study included 62 treatment-naïve patients with CRVO who received intravitreal injections of either ranibizumab or aflibercept. The demographic data, best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) characteristics were evaluated at baseline and at months 1, 2, 3, 6, 12 and 18 post-treatment.

RESULTS

At month 18, the mean BCVA of ranibizumab-treated eyes increased 7.9 letters, compared to 7.4 letters for eyes receiving aflibercept, with a similar number of injections. There was no statistically significant difference between the two groups in letters or in central subfield thickness at month 18. At the end of the follow-up, 50% of patients in the ranibizumab group and 42.9% in the aflibercept group showed complete resolution of macular edema.

CONCLUSIONS

Ranibizumab and aflibercept demonstrated similar anatomical and functional outcomes over 18-month follow-up in patients with macular edema due to CRVO, with a similar number of injections.

Serum and Vitreous Pentraxin 3 Concentrations in Patients with Diabetic Retinopathy

OBJECTIVE

Pentraxin 3 (PTX3), an acute-phase glycoprotein, is correlated with inflammation. Inflammation is mechanistically involved in the development of diabetic retinopathy (DR). This study was performed to investigate the association of serum and vitreous PTX3 concentrations with the occurrence of DR.

METHODS

This study enrolled 52 type 2 diabetes mellitus (T2DM) patients (20 without DR and 32 patients with proliferative diabetic retinopathy [PDR]). Serum and vitreous PTX3 concentrations were examined by using an enzyme-linked immunosorbent assay.

RESULTS

PDR patients showed significantly increased concentrations of serum and vitreous PTX3 concentrations compared with the control group and T2DM patients without DR. Higher serum and vitreous PTX3 concentrations were detected in T2DM patients without DR than those in the controls.

CONCLUSION

Serum and vitreous PTX3 concentrations are associated with the occurrence of DR.

Pro-Permeability Factors After Dexamethasone Implant in Retinal Vein Occlusion; the Ozurdex for Retinal Vein Occlusion (ORVO) Study

PURPOSE

To correlate aqueous vasoactive protein changes with macular edema after dexamethasone implant in retinal vein occlusion (RVO).

DESIGN

Prospective, interventional case series.

METHODS

Twenty-three central RVO (CRVO) and 17 branch RVO (BRVO) subjects with edema despite prior anti-vascular endothelial growth factor (VEGF) treatment had aqueous taps at baseline and 4 and 16 weeks after dexamethasone implant. Best-corrected visual acuity (BCVA) and center subfield thickness were measured every 4 weeks. Aqueous vasoactive protein levels were measured by protein array or enzyme-linked immunosorbent assay.

RESULTS

Thirty-two vasoactive proteins were detected in aqueous in untreated eyes with macular edema due to RVO. Reduction in excess foveal thickness after dexamethasone implant correlated with reduction in persephin and pentraxin 3 (Pearson correlation coefficients = 0.682 and 0.638, P = .014 and P = .003). Other protein changes differed among RVO patients as edema decreased, but ≥50% of patients showed reductions in hepatocyte growth factor, endocrine gland VEGF, insulin-like growth factor binding proteins, or endostatin by ≥30%. Enzyme-linked immunosorbent assay in 18 eyes (12 CRVO, 6 BRVO) showed baseline levels of hepatocyte growth factor and VEGF of 168.2 ± 20.1 pg/mL and 78.7 ± 10.0 pg/mL, and each was reduced in 12 eyes after dexamethasone implant.

CONCLUSIONS

Dexamethasone implants reduce several pro-permeability proteins providing a multitargeted approach in RVO. No single protein in addition to VEGF can be implicated as a contributor in all patients. Candidates for contribution to chronic edema in subgroups of patients that deserve further study include persephin, hepatocyte growth factor, and endocrine gland VEGF.

Systemic and Ocular Long Pentraxin 3 in Patients with Age-Related Macular Degeneration

Age-related macular degeneration (AMD) has been associated with both systemic and ocular alterations of the immune system. In particular dysfunction of complement factor H (CFH), a soluble regulator of the alternative pathway of the complement system, has been implicated in AMD pathogenesis. One of the ligands for CFH is long pentraxin 3 (PTX3), which is produced locally in the retinal pigment epithelium (RPE). To test the hypothesis that PTX3 is relevant to retinal immunohomeostasis and may be associated with AMD pathogenesis, we measured plasma PTX3 protein concentration and analyzed the RPE/choroid PTX3 gene expression in patients with AMD. To measure the ability of RPE cells to secrete PTX3 in vitro, polarized ARPE-19 cells were treated with activated T cells or cytokines (interferon (IFN)-gamma and/or tumor necrosis factor (TNF)-alpha) from the basolateral side; then PTX3 protein concentration in supernatants and PTX3 gene expression in tissue lysates were quantified. Plasma levels of PTX3 were generally low and did not significantly differ between patients and controls (P=0.307). No statistically significant difference was observed between dry and exudative AMD nor was there any correlation with hsCRP or CFH genotype. The gene expression of PTX3 increased in RPE/choroid with age (P=0.0098 macular; P=0.003 extramacular), but did not differ between aged controls and AMD patients. In vitro, ARPE-19 cells increased expression of the PTX3 gene as well PTX3 apical secretions after stimulation with TNF-alpha or activated T cells (P<0.01). These findings indicate that PTX3 expressed in the eye cannot be detected systemically and systemic PTX3 may have little or no impact on disease progression, but our findings do not exclude that locally produced PTX3 produced in the posterior segment of the eye may be part of the AMD immunopathogenesis.

Intravitreal thrombin activity is elevated in retinal vein occlusion

To evaluate whether intravitreal thrombin activity is elevated in eyes with branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO) in comparison to healthy controls. Prospective clinical case series of 19 patients with BRVO, 13 patients suffering from CRVO and nine participants serving as controls. Vitreous taps were extracted from the central vitreous body, 200 μl frozen/thawed sample was immediately stabilized with 200 μl 5% human albumin, and 200 μl mixture thereof was stabilized with 200 μl 2.5 mol/l arginine, pH 8.6. Thrombin activity was determined chromogenically. Intravitreal levels of vascular endothelial growth factor (VEGF) as a marker for blood-retina barrier (BRB) breakdown were measured by a commercial chemiluminescent enzyme immuno assay (R&D). Intravitreal thrombin activity and VEGF levels were 1.6 ± 1.2 mIU/ml (mean value ± SD; range: 0.2-4.2 mIU/ml) and 554 ± 568 pg/ml (range: 20-2005 pg/ml) in BRVO-affected eyes, 2.6 ± 1.2 mIU/ml (range: 0.8-5.2 mIU/ml) and 1332 ± 1350 pg/ml (range: 58-3943 pg/ml) in eyes suffering from CRVO as well as 0.8 ± 0.8 mIU/ml (range: 0.2-2.7 mIU/ml) and 115 ± 120 pg/ml (range: 32-431 pg/ml) in controls. There are significant differences of intravitreal thrombin activity and intravitreal VEGF levels between eyes with BRVO, CRVO, and controls (P = 0.007 and P = 0.003, Kruskal-Wallis test). Intravitreal thrombin activity is significantly correlated with intravitreal VEGF levels (r = 0656; P < 0.001, Pearson correlation). Intravitreal thrombin activity might serve as a new marker for BRB breakdown or macular fibrin deposition in ophthalmology. Significant differences of intravitreal thrombin activity between eyes with BRVO, CRVO, and healthy controls might offer new therapeutic strategies for RVO-affected eyes. The effect of oral and intravitrealy injected direct thrombin inhibitors needs to be evaluated in further investigations.

Increased expression of angiogenic and inflammatory proteins in the vitreous of patients with ischemic central retinal vein occlusion

Background

Central retinal vein occlusion (CRVO) is a common disease characterized by a disrupted retinal blood supply and a high risk of subsequent vision loss due to retinal edema and neovascular disease. This study was designed to assess the concentrations of selected signaling proteins in the vitreous and blood of patients with ischemic CRVO.

Methods

Vitreous and blood samples were collected from patients undergoing surgery for ischemic CRVO (radial optic neurotomy (RON), n = 13), epiretinal gliosis or macular hole (control group, n = 13). Concentrations of 40 different proteins were determined by an ELISA-type antibody microarray.

Results

Expression of proteins enriched in the vitreous (CCL2, IGFBP2, MMP10, HGF, TNFRSF11B (OPG)) was localized by immunohistochemistry in eyes of patients with severe ischemic CRVO followed by secondary glaucoma. Vitreal expression levels were higher in CRVO patients than in the control group (CRVO / control; p < 0.05) for ADIPOQ (13.6), ANGPT2 (20.5), CCL2 (MCP1) (3.2), HGF (4.7), IFNG (13.9), IGFBP1 (14.7), IGFBP2 (1.8), IGFBP3 (4.1), IGFBP4 (1.7), IL6 (10.8), LEP (3.4), MMP3 (4.3), MMP9 (3.6), MMP10 (5.4), PPBP (CXCL7 or NAP2) (11.8), TIMP4 (3.8), and VEGFA (85.3). In CRVO patients, vitreal levels of CCL2 (4.2), HGF (23.3), IGFBP2 (1.23), MMP10 (2.47), TNFRSF11B (2.96), and VEGFA (29.2) were higher than the blood levels (vitreous / blood, p < 0.05). Expression of CCL2, IGFBP2, MMP10, HGF, and TNFRSF11B was preferentially localized to the retina and the retinal pigment epithelium (RPE).

Conclusion

Proteins related to hypoxia, angiogenesis, and inflammation were significantly elevated in the vitreous of CRVO patients. Moreover, some markers known to indicate atherosclerosis may be related to a basic vascular disease underlying RVO. This would imply that local therapeutic targeting might not be sufficient for a long term therapy in a systemic disease but hypothetically reduce local changes as an initial therapeutic approach.

Elevated plasma pentraxin 3 and its association with retinal vein occlusion

Purpose

To evaluate plasma pentraxin 3 (PTX3) in patients with retinal vein occlusion (RVO), and investigate the possibility of its role as a predictive biomarker.

Methods

Nested case-control study. The study included 57 patients with RVO and 45 age- and gender-matched subjects without RVO as controls. Plasma PTX3 and C-reactive protein concentration were measured in both groups a posteriori from frozen samples by using an enzyme-linked immunosorbent assay kit.

Results

The measured PTX3 value for the RVO group was 1,508 ± 1,183 pg/mL (mean ± standard deviation) and 833 ± 422 pg/mL for the controls (p < 0.001). There was no significant difference in PTX3 levels between patients with central retinal vein occlusion and branched retinal vein occlusion (1,468 ± 1,300 vs. 1,533 ± 1,121 pg/mL; p = 0.818).

Conclusions

Our data seems to support the role of chronic inflammation and ischemia in the development of RVO. It is possible that PTX3 can be used as a diagnostic biomarker of RVO.

Role of inflammation in diabetic macular edema

Vitreous fluid levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor (sVEGFR)-2, soluble intercellular adhesion molecule (sICAM)-1, monocyte chemotactic protein (MCP)-1 and pentraxin 3 (PTX3) were measured by enzyme-linked immunosorbent assay in 36 patients with diabetic macular edema (DME) and 15 patients with macular hole (MH). Aqueous flare values were measured with a laser flare meter, and macular edema was examined by optical coherence tomography. Vitreous fluid levels of VEGF, sVEGFR-2, sICAM-1, MCP-1 and PTX3 were significantly higher in the patients with DME than in those with MH. There was a significant correlation between the vitreous fluid level of sVEGFR-2 and the levels of sICAM-1, MCP-1 and PTX3. The aqueous flare value was significantly correlated with the vitreous fluid levels of sVEGFR-2, sICAM-1, MCP-1 and PTX3. These findings suggest that inflammatory factors may induce an increase in vascular permeability and disrupt the blood-aqueous barrier in DME patients.