Prospective assessment of cytokines and regulatory proteins concentration in the tear fluid of POAG patients with various hypotensive effects after non-penetrating deep sclerectomy

The aim. To assess the dynamics of cytokine content in tear fluid of primary openangle glaucoma (POAG) patients at various terms after non-penetrating deep sclerectomy (NPDS) in relation to the functional state of the outflow tracts.

Material and methods. We carried out prospective examination of 65 patients with advanced stage of primary open-angle glaucoma after NPDS. Depending on the course of the postoperative period and the conditions for achieving the hypotensive effect of NPDS, all patients were divided into three groups: group 1 – with the optimal hypotensive effect; group 2 – with the conditional hypotensive effect; group 3 – with no hypotensive effect after NPDS. The intraocular pressure and the concentration of TGF-β, MMP-9, IL-6, IL-8, VEGF-A (121 and 165) in the tear fluid were studied using ELISA method in pre- and postoperative period. We studied the outflow tracts using optical coherence tomography and carried out ultrastructural analysis of filtering blebs tissue.

Results. In group 1, the minimum initial concentrations of IL-6, IL-8 and TGF-β in the tear fluid and their moderate increase in the postoperative period; high concentrations of MMP-9 at all stages and an increase in VEGF-A by 2 months after NPDS were registered. In group 2, there was a high level of VEGF-A in the tear fluid before and 2 months after NPDS, an increase in TGF-β, IL-6 and IL-8 in the tear fluid in the early period with their suppression in the late period, as well as an increase in MMP-9 in the early postoperative period. Group 3 had maximum concentrations of TGF-β and IL-8 in the tear fluid initially and in the early postoperative period, suppression of MMP-9 in the tear fluid 2 weeks after and of VEGF-A 2 months after NPDS.

Conclusion. Initially high concentrations of IL-6, IL-8, and TGF-β in the tear fluid and the suppression of MMP-9 and VEGF-A in the postoperative period contribute to the surgical failure of the NPDS.

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