Evaluation of the tear cytokine level in unilateral pterygium cases

The aim of this study is to determine proinflammatory and antiinflammatory cytokine levels and growth factor concentrations in tear samples of pterygium cases and thus to contribute to the elucidation of the immunological mechanism. Thirty patients with unilateral primary pterygium were included in the study. Age and sex matched 28 healthy participants without any ocular surface disorder constituted the control group. Tear samples were collected from both pterygium eye and healthy fellow eye of the patient group, and randomly selected one eye of the control group. In these tear samples, 30 different cytokine concentrations (GM-CSF, TNF-α, IL-2, IL-1β, IL-4, VEGF, HGF, EGF, IL-8, IL-17, MIP-1α, IL-10, IL-6, IL-5, IL-7, IL-15, IFN-α, IL-2R, IP-10, MIP-1β, Eotaxin, RANTES, MIG, IL-1RA, IL-12 ( p40/70), IL-13, FGF-Basic, IFN-γ, G-CSF, MCP-1) were evaluated with Luminex® technology. Median IL-1β (107.00 pg/ml), IL-17 (554.02 pg/ml) and VEGF (75.11 pg/ml) concentrations were statistically significantly higher in pterygium eyes than healthy fellow eyes (72.44 pg/ml, 427.25 pg/ml, 62.26 pg/ml), and than control group (59.27 pg/ml, 403.80 pg/ml, 37.74 pg/ml) (p <0,05). No statistically significant difference was found in the comparison of healthy fellow eyes and control group. In the pterygium group, the high co-existence of higher IL-1β, IL-17 and VEGF concentrations and being significantly correlated with each other suggested that many inflammatory and angiogenetic steps were involved in the pathogenesis of pterygium. Since IL-17 is also able to induce the VEGF pathway, systemic or topical agent use against IL-17 may be one of the future approaches in pterygium treatment.