Inflammatory cytokines in aqueous humor of patients with choroidal neovascularization

To investigate the correlations between aqueous concentrations of interleukin 1β, 6, 8, 10, 12p (IL-1β, IL-6, IL-8, IL-10, IL-12p), and tumor necrosis factor α (TNF-α) and the parameters of macular edema acquired by optical coherence tomography (OCT) in patients with choroidal neovascularization.

IL-1β, IL-6, IL-8, IL-10, IL-12p, and TNF-α in the aqueous humor samples of 17 patients with exudative age-related macular degeneration (AMD), ten patients with pathological myopia (PM), seven patients with idiopathic choroidal neovascularization (CNV), and 14 patients with cataract and idiopathic epiretinal membrane or macular hole in the control group were measured with cytometric bead array. The maximum macular thickness and macular volume within 1 mm, 3 mm, and 6 mm were measured with OCT.

In the CNV groups, the aqueous levels of IL-6 and IL-8 were significantly associated with macular volume within 6 mm (p=0.011, p=0.008, respectively), while IL-1β, IL-10, IL-12p, and TNF-α showed no significant correlation with either the maximum macular thickness or the macular volume. By further selecting patients with CNV who had accepted their last intravitreal injection of bevacizumab within 3 months, the level of IL-6 still significantly correlated with the maximum macular thickness (p=0.019) and macular volume within 1 mm (p=0.018), 3 mm (p=0.018), and 6 mm (p=0.022). In patients with exudative AMD, the level of IL-6 was significantly associated with the maximum macular thickness (p=0.025) and macular volume within 1 mm (p=0.025), 3 mm (p=0.006), and 6 mm (p=0.002). The aqueous level of all cytokines did not vary significantly between the CNV patients who had accepted their last intravitreal injection of bevacizumab within 3 months and the other patients, nor was a difference found among patients with exudative AMD, PM, and idiopathic CNV, and the control group.

Intraocular concentrations of IL-6 and IL-8 (particularly IL-6) are significantly associated with the volume of macular edema in patients with CNV. However, intravitreal injection of antivascular endothelial growth factor drugs did not change the intraocular level of these inflammation cytokines.