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

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.

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.

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.

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.