Short-Term Exposure To High Altitude On Dry Eye

High altitude, has emerged as primary exploration sites. While, there are still challenges, such as reduced oxygen pressure, the human eye, which is sensitive to the changes in oxygen concentration, hypoxia will lead to structural and functional changes of the eye, that indirectly interfere with the acquisition of visual information. 

Dry eye is the main index that reflects visual fatigue. In 2003, Thomas et al. suggested that high altitude could lead to an worsening in dry eye symptoms in patients.

Based on the above, we intend to further measure and quantify the trends of dry eye-related parameters under acute low-pressure hypoxia and try to analyze the causes, in order to provide valuable safety for working in high-altitude environments.

High altitude, has emerged as primary exploration sites. While, there are still challenges, such as reduced oxygen pressure, the human eye, which is sensitive to changes in oxygen concentration, hypoxia will lead to structural and functional changes of the eye, that indirectly interfere with the acquisition of visual information. 

Dry eye is the main index that reflects visual fatigue. In 2003, Thomas et al. suggested that high altitude could lead to an worsening in dry eye symptoms in patients.

The study group comprised 12 healthy male and 10 healthy female participants (44 eyes) aged of 20-24 years old. Measurements were taken at 5 altitudes (altitude1: ground; altitude 2: 3500 m; altitude 3: 4000 m; altitude 4: 4500 m, altitude 5: end of experiment). Data analysis was performed using the Kolmogorov–Smirnov test, Paired Sample T-test, Wilcoxon test, and analysis of variance for repeated measurements.

The tear break-up time decreased significantly with increasing altitude, and the differences between the altitude 1 and the values at altitude3 and altitude4 were significant. Additionally, tear film lipid layer thickness showed a fluctuating decrease with increasing altitude, rising only at altitude 4, and the differences between the previous 4 altitudes (altitude1, 2, 3 and 4) and altitude 5 were all significant.

This finding provides new data to support changes related to dry eye under hypoxia. It suggests that acute exposure to hypobaric hypoxia will lead to the aggravation of dry eye symptoms, thus causing more rapid visual fatigue. This, in turn, affects the ability and speed of visual information acquisition of high-altitude workers, thereby posing a certain safety threat to high-altitude work.