STHC caused a significant increase in IOP in healthy participants. But this significant increase in IOP cannot be solely explained by a CCT-related overestimation error due to the increase in CCT. Individuals with IOP-related disorders such as glaucoma should be cautious when facing potential exposure to hypobaric hypoxic conditions.

Alterations of amplitudes and implicit times of N2 response in the central area may be able to detect glaucoma earlier than VFA. In addition, with progression to advanced glaucoma these changes can be significant in all retinal areas. Although implicit times of all mfERG components are significantly delayed in glaucoma, both delayed implicit time and decreased amplitude of N2 wave in the central area are effective predictors in early glaucoma diagnosis.

Purpose:To ascertain whether the changes in intraocular pressure (IOP) that occur during hypobaric hypoxic exposure are related to plasma N-terminal pro-brain natriuretic peptide (BNP) levels.Materials and Methods:The study group comprised 26 healthy participants (all male, mean age 23.1 years). IOP was measured at local ground level, (792 m above sea level), then while in a chamber providing hypobaric hypoxic conditions (the subjects were exposed to a pressure equivalent to 9144 m for 1-3 min), and again after exit from the chamber. In each condition, the mean of three consecutive measurements of IOP was calculated for each eye. For BNP measurements, blood samples were drawn before the participants entered the chamber and just after they left the chamber.Results:IOP during hypobaric hypoxic exposure (18.00 ± 3.70 mmHg) was significantly greater than that before (15.66 ± 2.10 mmHg, P < 0.001) or after (16.10 ± 2.63 mmHg, P = 0.001) the exposure. IOP levels before and after the exposure were not significantly different (P = 0.136). Plasma BNP levels measured before and after exposure to hypobaric hypoxic conditions were not significantly different (P = 0.462).Conclusion:Plasma BNP levels did not change after short-term hypobaric hypoxic exposure, while the IOP increased. This increase may have been caused by some other systemic factors. As the hypobaric hypoxic conditions were reversed, IOP decreased to normal levels.