Tear cytokine profile of glaucoma patients treated with preservative-free or preserved latanoprost

Purpose

To determine variations in cytokine levels of glaucoma patients treated either with preservative-free latanoprost or preserved latanoprost, relative to healthy individuals.

Methods

Tear samples were collected from 39 healthy subjects, 20 glaucoma patients treated with preserved latanoprost, and 20 patients treated with preservative-free latanoprost. A set of 27 inflammatory cytokines was analyzed in each group, including interleukin (IL)-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL9, IL-10, IL-12 (p70), IL-13, IL-15, IL-17, eotaxin, fibroblast growth factor (FGF) basic, granulocyte colony stimulating factor (G-CSF), granulocyte monocyte colony stimulating factor (GM-CSF), interferon (IFN)-γ, interferon gamma-induced protein (IP)-10, monocyte chemo attractant protein (MCP)-1MCAF, macrophage inflammatory protein (MIP)-1α, MIP-1β, platelet-derived growth factor (PDGF)-BB, regulated on activation, normal T cell expressed and secreted (RANTES), tumor necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF). Cytokine concentrations were obtained by the Bio-Plex Human Cytokine Immunoassay. Non-invasive tear breakup time (NI-TBUT), tear meniscus height, corneal fluorescein staining, conjunctival hyperemia and ocular surface disease index (OSDI) were assessed in patients treated with preservative-free and preserved latanoprost.

Results

The levels of IL-2, IL-5, IL-10, IL-12 (p70), IL-13, IL-15, IL-17, FGF basic, PDGF-BB, and TNF-α were significantly higher in patients receiving preserved latanoprost, compared to normal controls (p < 0.05). The expression of all the cytokines studied remained statistically invariable in patients receiving preservative-free latanoprost, compared to healthy subjects (p > 0.05). Ocular surface parameters were not significantly different in both glaucoma groups, and no correlation between these clinical parameters and cytokine levels was observed.

Conclusions

Treatment with preserved latanoprost has a direct impact on tear cytokine levels, whereas this effect is not observed upon preservative-free latanoprost instillation.