Centre for Ophthalmology, University of Tübingen, Germany.
Invest Ophthalmol Vis Sci. 2013 Jun 21;54(6):4241-8. doi: 10.1167/iovs.13-12158.
This study aimed to quantify the impact of exposure to high altitude on individual layers of the cornea in regard to central corneal thickness (CCT) and the geometry of the anterior chamber angle (ACA). This work is related to the Tübingen High Altitude Ophthalmology study.
Anterior segment spectral domain optical coherence tomography was used to quantify changes in individual corneal layers and to study ACA and angle opening distance (AOD). Peripheral oxygen saturation, heart rate, and scores of acute mountain sickness (AMS) were assessed in 14 healthy subjects at baseline (341 m) and altitude (4559 m) for respective correlations.
Longitudinal analysis revealed a significant (P < 0.05) increase of CCT during altitude exposure (CCT(baseline) = 539.27 ± 32.30 μm; CCT(day1) = 558.87 ± 29.39 μm; CCT(day3) = 567.17 ± 33.40 μm; mean ± SD) due to stromal edema. This change was completely reversible upon descent. Geometric measures of aqueous outflow structures remained consistent with no significant changes in AOD or ACA. Incidence of AMS on day 1 was 64% followed by a decrease in AMS scores over time spent at high altitude; while AMS correlated significantly with stromal edema formation just after arrival (r = 0.71; P = 0.01), no correlation was found on day 3 (r = 0.05; P = 0.87); no correlations were found for vital parameters.
Significant stromal edema was found during exposure to high altitude in healthy subjects. This seems to occur due to decreased atmospheric pressure under hypoxia but independent of systemic acclimatization. Other measures of anterior chamber geometry remained stable during the challenge to hypoxic conditions at high altitude.
本研究旨在定量评估高海拔暴露对角膜各层（包括中央角膜厚度 [CCT] 和前房角 [ACA] 的几何结构）的影响。本工作与图宾根高海拔眼科学研究相关。
使用眼前节谱域光学相干断层扫描（OCT）定量评估角膜各层的变化，并研究 ACA 和房角开放距离（AOD）。在 14 名健康受试者中，分别在基线（341 米）和高海拔（4559 米）时评估外周血氧饱和度、心率和急性高山病（AMS）评分，并进行相关性分析。
纵向分析显示，在高海拔暴露期间 CCT 显著增加（P < 0.05）（CCT（基线）= 539.27 ± 32.30 μm；CCT（第 1 天）= 558.87 ± 29.39 μm；CCT（第 3 天）= 567.17 ± 33.40 μm；平均值 ± 标准差），这是由于基质水肿所致。这种变化在下降后完全可逆。房水流出结构的几何测量值保持不变，AOD 或 ACA 没有明显变化。第 1 天 AMS 的发生率为 64%，随着在高海拔地区停留时间的增加，AMS 评分逐渐降低；尽管 AMS 在抵达后即刻与基质水肿形成显著相关（r = 0.71；P = 0.01），但在第 3 天无相关性（r = 0.05；P = 0.87）；生命参数也没有相关性。
在健康受试者高海拔暴露期间发现明显的基质水肿。这似乎是由于低氧下气压降低所致，但与全身适应无关。在高海拔低氧条件下，前房角几何结构的其他测量值保持稳定。
