Department of Ophthalmology, Katharinenhospital Stuttgart, Stuttgart, Germany.
Department of Ophthalmology, University of Tübingen, Tübingen, Germany.
Br J Ophthalmol. 2019 Dec;103(12):1815-1819. doi: 10.1136/bjophthalmol-2018-313260. Epub 2019 Feb 15.
BACKGROUND/AIMS: The aim of this study was to investigate a change in visual acuity and contrast sensitivity (CS) during high altitude exposure in healthy subjects due to the effects of hypobaric hypoxia. This study is related to the Tübingen High Altitude Ophthalmology study.
Visual acuity and Weber CS were tested monocularly using the Freiburger Visual Acuity and Contrast Test under standardised conditions in 14 healthy subjects at high altitude at the Capanna Margherita (4559 m, Italy) and compared with baseline measurements in Tübingen (341 m, Germany). Intraindividual differences between baseline and follow-up examinations were calculated by multivariate analysis of variance for repeated measures. Clinical parameters of peripheral oxygen saturation (SpO) and heart rate (HR) as well as scores for acute mountain sickness (AMS) were correlated to psychophysical tests by Pearson's correlation coefficient.
A significant decrease in CS with a mean effect size of -0.13 logCS was found for Weber CS (day 1=-0.16±0.22, p=0.01; day 2=-0.10±0.2, p=0.049; day 3=-0.12±0.19, p=0.03) at high altitude compared with baseline. Visual acuity remained unchanged. Decreased CS correlated with SpO (r=0.53, p=0.046) but not with HR (r=- 0.16, p=0.59) and occurred irrespective of AMS at high altitude.
High altitude exposure leads to decreased CS. Changes occur independent of AMS. This finding is of clinical importance to trekkers and mountaineers exposed to high altitude as visual processing in particular under mesopic conditions at dusk and dawn is altered. Furthermore, it provides novel insight into hypoxia related changes in CS function.
背景/目的：本研究旨在探讨健康受试者在高海拔环境下由于低压缺氧的影响，视力和对比敏感度（CS）的变化。本研究与图宾根高海拔眼科研究有关。
在意大利玛格丽塔小屋（4559 米），14 名健康受试者在高海拔环境下，使用弗里堡视力和对比测试单眼测试，在标准条件下测试视力和 Weber CS，并与图宾根（德国，341 米）的基线测量值进行比较。通过重复测量的多元方差分析计算个体内基线和随访检查之间的差异。外周血氧饱和度（SpO）和心率（HR）的临床参数以及急性高山病（AMS）评分与心理物理测试相关联，采用 Pearson 相关系数进行分析。
与基线相比，在高海拔环境下 Weber CS 显著下降，平均效应大小为-0.13 logCS（第 1 天=-0.16±0.22，p=0.01；第 2 天=-0.10±0.2，p=0.049；第 3 天=-0.12±0.19，p=0.03）。视力保持不变。CS 下降与 SpO 相关（r=0.53，p=0.046），但与 HR 不相关（r=-0.16，p=0.59），并且无论在高海拔环境下是否患有 AMS，这种情况都会发生。
高海拔暴露会导致 CS 下降。这些变化与 AMS 无关。这一发现对暴露于高海拔环境的徒步旅行者和登山者具有重要的临床意义，因为在黄昏和黎明的微光条件下，视觉处理会发生改变。此外，这为 CS 功能与缺氧相关的变化提供了新的见解。
