Cytokine analysis to evaluate severity in primary open-angle glaucoma and exfoliative glaucoma.

Purpose: To analyze cytokines in tear and aqueous humour as biomarkers for evaluation of severity of glaucoma.

Design: Cross-sectional study.

Subjects and methods: Tear and aqueous humour samples were collected from 15 exfoliative glaucoma (XFG) patients, 43 primary open-angle glaucoma (POAG) patients and 33 controls (eligible for cataract surgery). A total of 27 inflammatory cytokines were analyzed in the tear and aqueous humor samples by the Bio-Plex Pro Human Cytokine 27-Plex Immunoassay kit: interleukin (IL)-1b, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL9, IL-10, IL-12, IL-13, IL-15, IL-17, eotaxin, fibroblast growth factor (FGF) basic, granulocyte colony-stimulating factor, granulocyte-monocyte colony-stimulating factor, interferon-γ, interferon gamma-induced protein, monocyte chemo-attractant protein-1, macrophage inflammatory protein (MIP)-1a, MIP-1b, platelet-derived growth factor, regulated on activation normal T cell expressed and secreted, tumor necrosis factor-α and vascular endothelial growth factor.

Results: In the tear samples a statistically significant difference in Il-2, IL-4, IL-9, IL-12, IL-15 and FGF-basic between study groups was observed. In aqueous humor, a statistically significant difference of the following cytokines was observed: IL-5, IL-6, IL-12 and MCP-1. Il-4 and IL-15 differences correlate with the number of topical drugs, while IL-9 and IL-15 are associated with the visual field mean defect.

Conclusion: Inflammation is strongly associated with glaucoma and some cytokines may be related to glaucoma severity.