Purpose
To quantify tear cytokine levels in Non-Dry eye (NDE) and Dry Eye (DE) participants before and after exposure to a Low Humidity-Environmental Exposure Chamber (LH-EEC).
Methods
Basal tear samples were collected (pre-exposure) from 8 NDE and 8 DE participants prior to their entry into the LH-EEC. The participants remained in the LH-EEC with controlled temperature (23±3°C), relative humidity (10±3%) and air velocity (3-5ft/sec) and performed visual tasking for 180 minutes. Prior to their exit, basal tears were collected (post-exposure). Subsequently, participants remained in the clinic and tears were collected again after 60 minutes (recovery). The collected tear samples were analyzed using the human pro-inflammatory V-plex assay (IFN-γ, IL-10, IL-12 p70, IL-13, IL-1β, IL-2, IL-4, IL-6, IL-8 and TNF-α) using the MesoScale Discovery Platform.
Results
There was a significant difference between the NDE and DE participants for IL-2 (p=0.009), however, no significant differences were seen between the two groups for other cytokines. The mean and standard deviation for each cytokine in the NDE and DE participants under 3 conditions are provided in the Table. Exposure to the EEC caused over 100% increase in the cytokine concentration in some participants.
Conclusions
Induction and reduction in tear cytokines vary after exposure to a controlled LH-EEC in NDE and DE participants. The LH-EEC model can be used to understand the role of tear film biomarkers in the pathogenesis of dry eye.
Keywords: 486 cornea: tears/tear film/dry eye