Association between systemic complement levels and choroidal thickness in advanced non-neovascular age-related macular degeneration
摘要
To investigate associations between systemic complement activation and choroidal thickness (CT) in advanced non-neovascular age-related macular degeneration (nnAMD). Cross-sectional study of 96 patients (187 eyes) with advanced nnAMD enrolled in the University of Colorado AMD Registry (August 2014–June 2021). Medical histories, multimodal imaging, and plasma samples were collected. Plasma was analyzed via enzyme-linked immunosorbent assay and multiplex Luminex assays for complement factors C1q, monoclonal B-cell lymphocytosis, C2, C4, C4b, C3, C3a, Factor B, Bb, Factor D, Factor H, Factor I, C5 and soluble C5b-9. CT was measured subfoveally and at 1000 μm intervals superiorly, inferiorly, nasally, and temporally using Spectralis OCT. Linear modeling with generalized estimating equations assessed log-transformed OCT and complement factors. The mean age was 82.2 years (± 7.1 SD); 54.2% were female. Average CT was negatively associated with Bb (β=-0.47, SE: 0.12, p = 0.0001) and the Bb/Factor B ratio (β=-0.28, SE: 0.12, p = 0.02), but not other complement markers. Bb levels correlated with alternative pathway components but not with classical or lectin pathway markers. We found a key association between systemic complement activation of Factor B and choroidal thickness in patients with advanced nnAMD, implying the potential involvement of the systemic alternative pathway in nnAMD patients.