To evaluate symptoms, signs and the levels of 16 tears inflammatory mediators of dry eye (DE) patients exposed to an environment simulating an in-flight air cabin in an environmental chamber.
Twenty DE patients were exposed to controlled environment simulating an in-flight airplane cabin [Simulated in-flight condition (SIC)] of 23ºC, 5% relative humidity, localized air flow, and 750 millibars (mb) of barometric pressure. As controls, 15 DE patients were subjected to a simulated standard condition (SSC) of 23ºC, 45% relative humidity, and 930 mb. A DE-symptoms questionnaire, diagnostic tests, and determination of 16 tear molecules by multiplex bead array were performed before and 2 hr after exposure.
After SIC exposure, DE patients became more symptomatic, suffered a significant (p≤0.05) decrease in tear stability (tear break-up time) (from 2.18±0.28 to 1.53±0.20), and tear production (Phenol red thread test), and a significant (p≤0.05) increase in corneal staining, both globally (0.50±0.14 before and 1.25 ± 0.19 after) and in each area (Baylor scale). After SSC, DE patients only showed a mild but significant (p≤0.05) increase in central and inferior corneal staining. Consistently, tear levels of IL-6 and MMP-9 significantly increased and tear EGF significantly decreased (p≤0.05) only after SIC.
The controlled adverse environment conditions in this environmental chamber can simulate the conditions in which DE patients might be exposed during flight. As this clearly impaired their lacrimal functional unit, it would be advisable that DE patients use therapeutic strategies capable of ameliorating these adverse episodes.
Invest Ophthalmol Vis Sci. 2013 Feb 14. pii: iovs.12-11361v1. doi: 10.1167/iovs.12-11361. [Epub ahead of print]
Teson M, Gonzalez-Garcia MJ, Lopez-Miguel A, Enriquez-de-Salamanca A, Martin-Montanez V, Benito MJ, Mateo ME, Stern ME, Calonge M.
IOBA, University of Valladolid, Valladolid, Spain.