Comparative analysis of tear cytokines in patients with glaucoma, ocular hypertension, and healthy controls

PurposeTo investigate the ocular surface inflammation in patients with primary open angle glaucoma and ocular hypertension by analyzing tears and to compare findings with healthy controls.MethodsObservational case-control study. Tear samples were collected by 5 mu l microcapillary tube from 24 patients with glaucoma treated by antiglaucoma drops, 9 non-treated patients with ocular hypertension and 45 healthy controls. Tears were analyzed from right eye by multiplex Bio-Plex system for the presence of 6 cytokines: IL1 beta, IL10, IL4, IFN gamma, MIF and VEGF.ResultsSignificantly higher concentrations of IL1 beta and IL10 (glaucoma or ocular hypertension vs. healthy controls, p < 0.0001), VEGF (glaucoma vs. ocular hypertension, p < 0.05; ocular hypertension vs. healthy controls, p < 0.02) and MIF (glaucoma vs. healthy controls, p < 0.03) were detected in patients' tears. Both patient groups have activated to a significantly lower extent the Th1 pathway represented by IFN gamma than Th2 pathway represented by IL10 (p < 0.001) and, at the same time, the IFN gamma/IL4 ratio was significantly increased in healthy controls (p < 0.001) and patients with ocular hypertension (p < 0.02) compared to glaucoma individuals.ConclusionThis study shows that secretion of inflammation-related cytokines by conjunctival cells is increased in both, glaucoma and ocular hypertension patients and can be detected in their tears. Nevertheless, data indicates stronger ocular surface inflammation in non-treated follow-up patients diagnosed with ocular hypertension than in glaucoma subjects treated by antiglaucoma drops.