Correlation analysis of morphofunctional and immunological parameters in patients with advanced stages of primary open-angle glaucoma

Abstract

PURPOSE. To study the correlations between the immunological data and the indicators of electroretinography (ERG) and optical coherence tomography (OCT) in patients with advanced stages of primary open-angle glaucoma (POAG).METHODS. Previously, we conducted a multimodal study of patients with advanced stages of glaucoma involving ERG, morphometric and immunological studies. In this new study we performed a correlation analysis of the immunological and morphofunctional data of patients with advanced stages of POAG. The study included 35 patients (35 eyes), among them 19 women and 16 men, who were divided into two groups: group 1 — stage II POAG (12 patients, 12 eyes), and group 2 — stage III POAG (23 patients, 23 eyes). The average age of the subjects was 64.2±6.5 years. Intraocular pressure was compensated in all study patients. The Pearson's correlation coefficient was used to calculate the linear relationship between continuous features.RESULTS. In the subgroup with stage II POAG significant correlations of moderate strength (according to the Chaddock scale) were found between the parameters of pattern ERG (PERG) and photopic negative response (PhNR) and the level of VEGF-A in the blood serum (BS), EGF in the tear fluid (TF) and aqueous humor (AH); strong correlations — for the concentrations of EGF and TGF-β2 in the AH. In group 2, moderate correlations between PERG and PhNR parameters and the level of IL-1RA in the TF were found, as well as moderate correlation of TGF-β2 expression in the AH with PnHR amplitude from the baseline. In patients with stage II glaucoma, the levels of MIP-1β/CCL4 in the TF, IL-1RA in the intraocular fluid correlated with the thickness of the retinal nerve fiber layer (RNFL) and retinal ganglion cell layer (GCL), while the EGF in the TF and AH correlated with RNFL thickness. In the group with stage III POAG, correlations of moderate strength were found for the expression level of TNF-α, IL-8/CXCL8 in the TF and RNFL thickness, and strong correlations — for the level of IP-10/CXCL10, HGF/SF, TGF-β2 in AH and the thickness of RNFL and GCL.CONCLUSION. Comparison of ERG, OCT findings and the level of cytokines of various biological effects in the BS, TF and AH confirmed the high informativeness of PERG and PhNR indicators and immunological data as markers of advanced stages of POAG, and allow EGF to be considered as the most promising pathogenetically oriented immunological marker of II and III stages of glaucoma.