Aqueous humor cytokine levels in patients with polypoidal choroidal vasculopathy and neovascular age-related macular degeneration.

Purpose: To investigate the possible roles of various cytokines or growth factors in the pathogenesis of exudative age-related macular degeneration (AMD) by comparing aqueous humor levels of 14 cytokines between eyes with polypoidal choroidal vasculopathy (PCV) and those with neovascular AMD.

Methods: Forty eyes from 40 patients with treatment-naïve exudative AMD consisting of 18 eyes with neovascular AMD and 22 eyes with PCV were studied. Twenty eyes from 20 patients with no retinal pathology who underwent cataract surgery served as controls. Aqueous humor samples were collected just before intravitreal ranibizumab injection in 40 eyes with exudative AMD and before cataract surgery in 20 control eyes. Concentrations of 14 cytokines were determined by chemiluminescence-based ELISA: interleukin (IL)-1α, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, vascular endothelial growth factor (VEGF), monocyte chemoattractant protein 1, interferon-γ-inducible protein (IP)-10 and C-reactive protein (CRP).

Results: After adjusting for gender, age and axial length, concentrations of CRP and IP-10 were significantly higher in eyes with neovascular AMD or PCV compared with control eyes (p < 0.05), and IP-10 levels were strongly associated with lesion size (p = 0.002). None of the 14 cytokines, including VEGF, were significantly different between eyes with neovascular AMD and those with PCV.

Conclusion: Aqueous humor concentrations of CRP and IP-10 were elevated in eyes with PCV or neovascular AMD. IP-10 could be associated with the pathogenesis of neovascular AMD and PCV.