To compare the aqueous concentrations of cytokines in glaucomatous eyes with those of normal controls and to characterize the clinical factors associated with aqueous cytokine concentration.

In this cross-sectional study, aqueous humor samples were collected from 54 eyes of 54 patients (34 medically treated primary open angle glaucoma and 20 normal controls) during cataract surgery from January 2014 to January 2015. Glaucoma patients were divided into two groups: patients using prostaglandin analogue for more than 6 months (prostaglandin F2α analogue [PGA] user) and patients with no experience of PGA use (PGA non-user). The levels of cytokines (matrix metalloproteinase [MMP]1, MMP9, MMP3, vascular endothelial growth factor, interleukin [IL]-1, IL-8, tumor necrosis factor [TNF]-α) in the aqueous of glaucoma and control subjects were quantified using a multiplex cytokine analysis.

Aqueous humor collected from the glaucoma patients exhibited significantly increased concentrations of MMP1 ( p = 0.002) and MMP9 ( p = 0.026). Among glaucoma patients, PGA users showed significantly higher level of MMP 9 compared with PGA non-users ( p = 0.003). In the univariate and multivariate linear regression analyses, PGA use (β = 0.351, p = 0.027) and vertical cup-to disc ratio (β = -0.401, p = 0.013) were the significant risk factors associated with the level of MMP9.

Primary open-angle glaucoma showed increased aqueous levels of MMP1 and MMP9. Especially, PGA use for longer than 6 months was associated with increased level of MMP9.