Purpose: To study the effects of eye closure on the balance of tear cytokines.
Methods: A total of 17 healthy volunteers with normal eyes were recruited. Tears (10 microl) were collected by capillary outflow at 09:00. The right eyes were closed with cotton bandages for 3 h, then tears were collected from each eye separately. The concentrations of inflammatory cytokines, interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12p70, and tumor necrosis factor (TNF)-alpha were measured by cytometric bead array.
Results: Although the concentration of each cytokine varied between eyes, the increasing ratio for 3 h showed a similar pattern in each cytokine. IL-1beta, IL-6, IL-10, IL-12p70, and TNF-alpha increased and IL-8 decreased in normal eyes. After eye closure, the increase of IL-10 significantly diminished (P=0.037); however, the other cytokines were not affected.
Conclusions: Eye closure decreased the concentration of IL-10 in tears, which might cause a potentially pro-inflammatory status of the ocular surface.