Evaluation of aqueous cytokine levels in eyes with Fuchs endothelial corneal dystrophy and bullous keratopathy

Abstract

To evaluate cytokine levels in the aqueous humor (AH) of patients with Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK). The study included 74 patients (74 eyes). The first group consisted of 31 patients (72.7±9.2 years) with FECD; the second group included 35 patients (72.4±9.1 years) with BK. The control group comprised 8 patients (74.3±4.1 years) with immature cataract. Before surgery, patients underwent pachymetry of the central cornea (RTvue-100 OCT, Optovue, USA). Patients of groups 1 and 2 underwent endothelial keratoplasty (DSAEK or DMEK), or penetrating corneal transplantation. Patients of the control group underwent phacoemulsification with implantation of intraocular lens. The initial stage of the surgery involved AH sample collection for evaluation of cytokine levels (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p70), IL-13, IL-17, G-CSF, GM-CSF, IFNγ, MCP-1, MIP-1β and TNF-α) by fluorescent flow cytometry using the Bio-Plex Pro Human Cytokine Panel, 17-plex (Bio-Rad, USA). Multiplex analysis of the AH content did not show any statistically significant differences in cytokine levels between decompensated FECD and BK eyes. The levels of IL-6, IL-8, GM-CSF, IFNγ, MCP-1, MIP-1β were significantly elevated in FECD and BK eyes compared with healthy control. An insignificant deviation of IL-4 and IL-13 levels was detected in FECD and BK eyes compared with healthy controls. There were no significant differences in IL-1β and TNF-α (indicators of acute inflammation) between the study groups. The obtained data confirm that FECD and BK are associated with disruption of ocular immune privilege that leads to chronic local inflammation, which in turn causes remodeling of the corneal tissues resulting in fibrosis.