PURPOSE: To assess the effect of short-term hypobaric hypoxic exposure on central corneal thickness (CCT) in healthy participants in 2 different age groups. METHODS: Seventy eyes in 35 healthy men were investigated. Twenty participants (mean age 22.8 +/- 0.6 years) comprised 1 group, and 15 (mean age 32.1 +/- 2.8 years) comprised another group. CCT was measured via ultrasound pachymetry initially at local ground level (792 m above sea level), then during short-term hypobaric hypoxic exposure (equivalent to 9144 m altitude), and then again under ground level conditions. The mean of 10 consecutive CCT measurements in each eye under each set of conditions was used in statistical analysis. RESULTS: In the younger group, initial CCT was 561.5 +/- 36.1 microm. This increased to 562.3 +/- 36.7 microm under hypobaric hypoxic conditions, and after the return to local ground level conditions, CCT decreased to 560.1 +/- 34.5 microm. CCT values under hypobaric hypoxic conditions were not significantly different from those measured before or afterward (P > 0.05). In the older group, initial CCT was 566.0 +/- 33.7 microm. This increased to 576.9 +/- 28.5 microm under hypobaric hypoxic conditions, and after the return to local ground level conditions, CCT decreased to 567.9 +/- 33.3 microm. In the older group, CCT values under hypobaric hypoxic conditions were significantly greater than those measured initially (P < 0.001) or afterward (P < 0.01). In both age groups, initial CCT did not differ significantly from final CCT (P > 0.05). CONCLUSION: Short-term hypobaric hypoxic exposure increased CCT significantly in the older age group, whereas it yielded a nonsignificant minor increase in the younger age group.
PURPOSE: To assess the effect of short-term hypobaric hypoxic exposure on central corneal thickness (CCT) in healthy participants in 2 different age groups. METHODS: Seventy eyes in 35 healthy men were investigated. Twenty participants (mean age 22.8 +/- 0.6 years) comprised 1 group, and 15 (mean age 32.1 +/- 2.8 years) comprised another group. CCT was measured via ultrasound pachymetry initially at local ground level (792 m above sea level), then during short-term hypobaric hypoxic exposure (equivalent to 9144 m altitude), and then again under ground level conditions. The mean of 10 consecutive CCT measurements in each eye under each set of conditions was used in statistical analysis. RESULTS: In the younger group, initial CCT was 561.5 +/- 36.1 microm. This increased to 562.3 +/- 36.7 microm under hypobaric hypoxic conditions, and after the return to local ground level conditions, CCT decreased to 560.1 +/- 34.5 microm. CCT values under hypobaric hypoxic conditions were not significantly different from those measured before or afterward (P > 0.05). In the older group, initial CCT was 566.0 +/- 33.7 microm. This increased to 576.9 +/- 28.5 microm under hypobaric hypoxic conditions, and after the return to local ground level conditions, CCT decreased to 567.9 +/- 33.3 microm. In the older group, CCT values under hypobaric hypoxic conditions were significantly greater than those measured initially (P < 0.001) or afterward (P < 0.01). In both age groups, initial CCT did not differ significantly from final CCT (P > 0.05). CONCLUSION: Short-term hypobaric hypoxic exposure increased CCT significantly in the older age group, whereas it yielded a nonsignificant minor increase in the younger age group.