Inflammatory Factors of Macular Atrophy in Eyes With Neovascular Age-Related Macular Degeneration Treated With Aflibercept

Macular Atrophy in Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

TOPIC

Macular atrophy incidence in neovascular age-related macular degeneration (AMD) patients undergoing anti-vascular endothelial growth factor (VEGF) treatment.

CLINICAL RELEVANCE

Macular atrophy is a significant event that may occur in eyes with neovascular AMD treated with anti-VEGF therapy.

METHODS

We conducted a systematic review and meta-analysis following PRISMA guidelines (PROSPERO, CRD42024474924). A comprehensive literature search of MEDLINE, EMBASE, and Web of Science was performed up to November 1, 2023. Randomized and non-randomized studies of treatment-naïve neovascular AMD patients reporting macular atrophy incidence at 24±3 months after anti-VEGF therapy were eligible for inclusion in this review. Two independent reviewers conducted screening, data extraction, and quality assessment. For randomized controlled trials, the Cochrane Risk of Bias 2 tool was employed, while non-randomized studies were evaluated using the ROBINS-I tool. Random-effects meta-analysis models were used for quantitative synthesis, accounting for study variability. Heterogeneity was assessed with the I2 statistic, and publication bias by funnel plots and Egger's test. The primary outcome was the incidence of new macular atrophy at 24 months post-anti-VEGF therapy, with secondary outcomes at 12 months. Atrophy was diagnosed using color fundus photograph (CFP), fluorescein angiography (FA), fundus autofluorescence (FAF), optical coherence tomography (OCT), or multimodal imaging.

RESULTS

Twenty-three studies met the inclusion criteria for qualitative analysis, with 11 included in the meta-analysis (N=3,013 eyes). The pooled 24-month incidence of macular atrophy was 29% (95% confidence interval [CI]:20%-38%,I2=93%). Subgroup analysis revealed incidence rates of 26% (95% CI:15%-37%,I2=88%) for 814 eyes with Type 1/2 macular neovascularization (MNV), 49% (95% CI:18%-80%,I2=92%) for Type 3 MNV (N=230 eyes), and 29% (95% CI:18%-40%,I2=96%) for all MNV types (N=2,131 eyes). The pooled 12-month incidence among 2,214 eyes was 11% (95% CI:4%-18%,I2=93%). The certainty of evidence regarding the incidence of macular atrophy after anti-VEGF treatment, as assessed by GRADE, was low.

CONCLUSIONS

While this meta-analysis has limitations, including a moderate risk of bias in non-randomized studies, inconsistencies in the results indicated by high heterogeneity, and imprecision due to the different imaging modalities used to diagnose macular atrophy, our results suggest that macular atrophy could be a common complication in neovascular AMD patients receiving anti-VEGF therapy.

The role of immune modulators in age-related macular degeneration

We provide an overview of the expanding literature on the role of cytokines and immune mediators in pathophysiology of age-related macular degeneration (AMD). Although many immunological mediators have been linked to AMD pathophysiology, the broader mechanistic picture remains unclear with substantial variations in the levels of evidence supporting these mediators. Therefore, we reviewed the literature considering the varying levels of supporting evidence. A Medical Subject Headings (MeSH) term-based literature research was conducted in September, 2023, consisting of the MeSH terms "cytokine" and "Age-related macular degeneration" connected by the operator "AND". After screening the publications by title, abstract, and full text, a total of 146 publications were included. The proinflammatory cytokines IL-1β (especially in basic research studies), IL-6, IL-8, IL-18, TNF-α, and MCP-1 are the most extensively characterised cytokines/chemokines, highlighting the role of local inflammasome activation and altered macrophage function in the AMD pathophysiology. Among the antiinflammatory mediators IL-4, IL-10, and TGF-β were found to be the most extensively characterised, with IL-4 driving and IL-10 and TGF-β suppressing disease progression. Despite the extensive literature on this topic, a profound understanding of AMD pathophysiology has not yet been achieved. Therefore, further studies are needed to identify potential therapeutic targets, followed by clinical studies.

Anterior Chamber Flare as a Non-Invasive Assessment of Intraocular Immune Status and Ocular Complications in Proliferative Diabetic Retinopathy

Proliferative diabetic retinopathy (PDR) is a vision-threatening complication of diabetes mellitus (DM). Anterior chamber (AC) flare and intraocular cytokines are potent biomarkers reflecting the intraocular immune status in PDR. This study aimed to elucidate the complex interrelationship between AC flare and intraocular cytokines in PDR eyes. A retrospective observational study was conducted on 19 PDR eyes of 19 patients with type 2 DM, and on 19 eyes of 19 patients with idiopathic macular hole or epiretinal membrane as controls. AC flare was measured before pars plana vitrectomy (PPV). Aqueous humor (AH) and vitreous fluid (VF) samples were collected at the time of PPV, and the quantities of 27 cytokines in both intraocular fluids were analyzed. In the PDR and control groups, Spearman's rank correlation analysis revealed a positive correlation between AC flare and IL-8 level in both AH and VF. Additionally, IL-8 levels in AH correlated positively with IL-8 levels in VF. In the PDR group, receiver operating characteristic curve analysis identified IL-8 level in AH as a significant predictor for both diabetic macular edema (DME) and vitreous hemorrhage (VH) complications. The cut-off values of IL-8 were established at ≥26.6 pg/mL for DME and ≥7.96 pg/mL for VH. Given the positive correlation between AC flare and AH IL-8 level, the present findings suggest that AC flare value may potentially be a non-invasive biomarker for predicting DME.

Classification of Peripheral Blood Leukocyte Phenotypes and Serum Cytokines in Vogt-Koyanagi-Harada Disease before and after Glucocorticoid Therapy

Vogt-Koyanagi-Harada disease (VKH) is an autoimmune disease, and glucocorticoid therapy (GC) is widely used for VKH. We provided a profile of leukocyte populations and serum cytokines in VKH patients under GC. A prospective observational study was conducted on three treatment-naïve VKH patients. Peripheral blood samples were collected from the patients before GC (VKH-acute) and after 6 months (VKH-remission), and healthy individuals were used as controls. Proportions of 37-type leukocytes and levels of 27-kind cytokines were measured by mass cytometry and multiplex bead analysis. Property similarity was analyzed using hierarchical cluster analysis. The leukocytes and cytokines were broadly classified into four and three clusters: (1) a cluster with high intensity in VKH-acute consisting of B cells, Th2-like, Th17-like, basophils, and IL-7 and IP-10; (2) a cluster with high intensity in VKH-remission composed of monocytes, neutrophils, IL-4, and TNFα; in leukocytes, (3) a cluster with low intensity in VKH-acute and -remission consisting of CD8+ T cells, Th1-like, and NKT cells; (4) a cluster with low intensity in VKH-remission composed of NK cells, Tregs, and DCs; and in cytokines, (5) a cluster with high intensities in VKH-acute and -remission comprising G-CSF, MCP-1, eotaxin, and IL-17A. These findings suggest that inflammatory composition in blood during the acute phase of VKH represents complex hyperimmune responses dominantly driven by Th and B cells.

Evaluating the long-term biological stability of cytokine biomarkers in ocular fluid samples

PURPOSE

The quality of biological fluid samples is vital for optimal preanalytical procedures and a requirement for effective translational biomarker research. This study aims to determine the effects of storage duration and freeze-thawing on the levels of various cytokines in the human aqueous humour and vitreous samples.

METHODS AND ANALYSIS

Human ocular aqueous humour and vitreous samples were obtained from 25 eyes and stored at -80°C for analysis. All samples were assayed for 27 cytokine biomarker concentrations (pg/mL) using a multiplex assay. Four sample storage durations following sample collection were evaluated (1 week, 3 months, 9 months and 15 months). Additionally, samples underwent up to three freeze-thaw cycles within the study period.

RESULTS

Among the 27 cytokine biomarkers, concentrations of four cytokines (Interleukin (IL)-2, IL-10, IL-12 and platelet-derived growth factor-BB) were significantly decreased by storage duration at all time points, as early as 3 months following sample collection (range of 9%-37% decline between 1 week and 15 months, p<0.001). Freeze-thawing of up to three cycles did not significantly impact the cytokine biomarker concentrations in aqueous humour or vitreous. Separability of patient-specific cytokine biomarker profiles in the principal component analysis remained relatively the same over the 15 months of storage duration.

CONCLUSION

The findings from this study suggest that several intraocular cytokine biomarkers in human aqueous humour and vitreous samples may be susceptible to degradation with long-term storage, as early as 3 months after collection. The overall patient-specific cytokine biomarker profiles are more stable than concentrations of individual cytokines. Future studies should focus on developing guidelines for optimal and standardised sample handling methods to ensure correct research findings about intraocular biomarkers are translated into clinical practice.

RIPK1 and RIPK3 inhibitors: potential weapons against inflammation to treat diabetic complications

Diabetes mellitus is a metabolic disease that is characterized by chronic hyperglycemia due to a variety of etiological factors. Long-term metabolic stress induces harmful inflammation leading to chronic complications, mainly diabetic ophthalmopathy, diabetic cardiovascular complications and diabetic nephropathy. With diabetes complications being one of the leading causes of disability and death, the use of anti-inflammatories in combination therapy for diabetes is increasing. There has been increasing interest in targeting significant regulators of the inflammatory pathway, notably receptor-interacting serine/threonine-kinase-1 (RIPK1) and receptor-interacting serine/threonine-kinase-3 (RIPK3), as drug targets for managing inflammation in treating diabetes complications. In this review, we aim to provide an up-to-date summary of current research on the mechanism of action and drug development of RIPK1 and RIPK3, which are pivotal in chronic inflammation and immunity, in relation to diabetic complications which may be benefit for explicating the potential of selective RIPK1 and RIPK3 inhibitors as anti-inflammatory therapeutic agents for diabetic complications.

Clinical features and associated factors of intraocular inflammation following intravitreal brolucizumab as switching therapy for neovascular age-related macular degeneration

PURPOSE

The aim of this study is to explore the clinical features and associated factors of intraocular inflammation (IOI) following intravitreal brolucizumab (IVBr) administration for neovascular age-related macular degeneration (nAMD).

METHODS

This retrospective study included 87 eyes from 87 Japanese patients with nAMD who were followed up for 5 months after the initial administration of IVBr as switching therapy. Clinical pictures of IOI post-IVBr and changes in best corrected visual acuity (BCVA) at 5 months were evaluated between eyes with and without IOI (non-IOI). The association between IOI and baseline factors (age, sex, BCVA, hypertension, and/or arteriosclerotic changes in the fundus, subretinal hyperreflective material [SHRM], and macular atrophy) was evaluated.

RESULTS

Of the 87 eyes, 18 (20.6%) developed IOI and 2 (2.3%) developed retinal artery occlusion. There were 9 (50%) cases of posterior or pan-uveitis among eyes with IOI. The mean interval from initial IVBr administration to IOI was 2 months. The mean changes in logMAR BCVA at 5 months were significantly worse in IOI eyes than in non-IOI eyes (0.09 ± 0.22 vs. - 0.01 ± 0.15, P = 0.03). There were 8 (44.4%) and 7 (10.1%) cases of macular atrophy and 11 (61.1%) and 13 (18.8%) cases of SHRM in the IOI and non-IOI groups, respectively. SHRM and macular atrophy were significantly associated with IOI (P = 0.0008 and P = 0.002, respectively).

CONCLUSION

In IVBr therapy for nAMD, eyes with SHRM and/or macular atrophy should be observed more meticulously, given the increased risk of developing IOI, which is associated with insufficient BCVA gain.

Association between Systemic Factors and Vitreous Fluid Cytokines in Proliferative Diabetic Retinopathy

Proliferative diabetic retinopathy (PDR) is a vision-threatening complication of diabetes mellitus (DM). Systemic and intraocular factors are intricately related to PDR, and vitreous fluid (VF) cytokines are representative intraocular biomarkers. However, the associations between systemic factors and VF cytokines and their influence on PDR pathology are unclear. This study aimed to examine the correlation between systemic factors and VF cytokines and analyze their contributions to the pathology of PDR using multivariate analyses. We conducted a retrospective observational study on 26 PDR eyes of 25 patients with type 2 DM, and 30 eyes of 30 patients with idiopathic macular hole or epiretinal membrane as controls. Fifteen systemic and laboratory tests including blood pressure (BP) and body mass index (BMI), and 27 cytokines in VF were analyzed. BP and BMI correlated positively with VF levels of IL-6 and IP-10 in PDR patients, while no significant correlation was found between systemic factors and VF cytokines in controls. MCP-1 and VEGF-A in VF separately clustered with different systemic factors in controls, but these cytokines lost the property similarity with systemic factors and acquired property similarity with each other in PDR. Systemic factors contributed to only 10.4%, whereas VF cytokines contributed to 42.3% out of 52.7% variance of the whole PDR dataset. Our results suggest that intraocular factors play a major role in the pathology of PDR, whereas systemic factors may have limited effects, and that BP and BMI control in PDR could be useful interventions to improve intraocular immune condition.

The Role of Inflammation in Age-Related Macular Degeneration: Updates and Possible Therapeutic Approaches

Age-related macular degeneration (AMD) is a common retinal disease characterized by complex pathogenesis and extremely heterogeneous characteristics. Both in "dry" and "wet" AMD forms, the inflammation has a central role to promote the degenerative process and to stimulate the onset of complications. AMD is characterized by several proinflammatory stimuli, cells and mediators involved, and metabolic pathways. Nowadays, inflammatory biomarkers may be unveiled and analyzed by means of several techniques, including laboratory approaches, histology, immunohistochemistry, and noninvasive multimodal retinal imaging. These methodologies allowed to perform remarkable steps forward for understanding the role of inflammation in AMD pathogenesis, also offering new opportunities to optimize the diagnostic workup of the patients and to develop new treatments. The main goal of the present paper is to provide an updated scenario of the current knowledge regarding the role of inflammation in "dry" and "wet" AMD and to discuss new possible therapeutic strategies.