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

Background: Neovascular age-related macular degeneration (nAMD) is a leading cause of blindness in older people. Low-grade inflammation is well-known as one of the pathogenic mechanisms in nAMD. Anti-vascular endothelial growth factor (VEGF) therapy is the first-line treatment for nAMD, although macula atrophy (MA) developed under anti-VEGF therapy causes irreversible visual function impairment and is recognized as a serious disorder. Here, we show specific expression patterns of aqueous humor (AH) cytokines in nAMD eyes developing MA under intravitreal injection of aflibercept (IVA) as an anti-VEGF antibody and present predictive cytokines as biomarkers for the incidence of MA in nAMD eyes under IVA treatment. Methods: Twenty-eight nAMD patients received three consecutive monthly IVA, followed by a pro re nata regimen for 2 years. AH specimens were collected before first IVA (pre-IVA) and before third IVA (post-IVA). AH cytokine levels, visual acuity (VA), and central retinal thickness (CRT) were measured. Results: Two-year incidence of MA was 21.4%. In nAMD eyes developing MA [MA (+) group], pre-IVA levels of monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein (MIP)-1 beta, VEGF and post-IVA level of MCP-1 were higher than those in nAMD eyes without MA [MA (-) group]. In hierarchical cluster analysis, pre-IVA MCP-1 and VEGF were grouped into the same subcluster, as were post-IVA MCP-1 and CRT. In principal component analysis, principal component loading (PCL) of pre-IVA interferon-?-inducible protein 10 (IP-10) was 0.61, but PCL of post-IVA IP-10 decreased to -0.09. In receiver operating characteristic analysis and Kaplan-Meier curves, pre-IVA MCP-1, MIP-1 beta, and VEGF and post-IVA interleukin-6, MCP-1, and MIP-1 beta were detected as predictive factors for MA incidence. In 2-year clinical course, changes of VA in groups with high levels of pre-IVA MIP-1 beta (over 39.9 pg/ml) and VEGF (over 150.4 pg/ml) were comparable to those in MA (+) group. Conclusion: Substantial loss of IP-10 effects and persistent inflammation contribute to incidence of MA, and screening of AH cytokine levels could be a useful method to predict MA incidence in nAMD eyes under anti-VEGF therapy.

Automated summary

In patients with neovascular age-related macular degeneration, changes in predictive cytokines can be used as biomarkers for predicting the occurrence of macula atrophy, with substantial loss of interferon-?-inducible protein 10 (IP-10) effects and persistent inflammation playing an important role in the incidence of macula atrophy.