Schatz Andreas, Guggenberger Vanessa, Fischer M Dominik, Schommer Kai, Bartz-Schmidt Karl Ulrich, Gekeler Florian, Willmann Gabriel
Department of Ophthalmology, University of Tübingen, Tübingen, Germany.
Department of Ophthalmology, Katharinenhospital, Stuttgart, Germany.
Br J Ophthalmol. 2018 Jul 4. doi: 10.1136/bjophthalmol-2018-312224.
BACKGROUND/AIMS: The study aims to investigate changes in the optic nerve sheath diameter (ONSD) at high altitude and to assess correlation to optic disc oedema (ODE) and acute mountain sickness (AMS). This investigation is part of the Tübingen High Altitude Ophthalmology study.
Fourteen volunteers ascended to 4559 m for 4 days before returning to low altitude. Ultrasonography of ONSD, quantification of optic disc parameters using a scanning laser ophthalmoscope and fluorescein angiography were performed at 341 m and at high altitude. Pearson's coefficient was used to correlate changes in ONSD with the optic disc and AMS. Assessment of AMS was performed using the Lake Louise (LL) and AMS-cerebral (AMS-C) scores of the Environmental Symptom Questionnaire-III. All volunteers were clinically monitored for heart rate (HR) and oxygen saturation (SpO).
The mean ONSD at high altitude (4.6±0.3 mm, p<0.05) was significantly increased compared with baseline (3.8±0.4 mm) and remained enlarged throughout high-altitude exposure. This change in ONSD did not correlate with AMS (AMS-C, r=0.26, p=0.37; LL, r=0.21, p=0.48) and high-altitude headache (r=0.54, p=0.046), or clinical parameters of SpO (r=0.11, p=0.72) and HR (r=0.22, p=0.44). Increased ONSD did not correlate with altered key stereometric parameters of the optic disc describing ODE at high altitude (r<0.1, p>0.5).
High-altitude exposure leads to marked oedema formation of the optic nerve independent of AMS. Increased ONSD and ODE reflect hypoxia-driven oedema formation of the optic nerve at high altitude, providing important pathophysiological insight into high-altitude illness development and for future research.
背景/目的：本研究旨在调查高海拔地区视神经鞘直径（ONSD）的变化，并评估其与视盘水肿（ODE）和急性高原病（AMS）的相关性。本调查是图宾根高海拔眼科研究的一部分。
14名志愿者先上升到4559米处并停留4天，之后再返回低海拔地区。在海拔341米处和高海拔地区分别进行ONSD的超声检查、使用扫描激光检眼镜对视盘参数进行定量分析以及荧光素血管造影。采用Pearson系数来关联ONSD的变化与视盘及AMS情况。使用环境症状问卷-III的路易斯湖（LL）评分和AMS-脑（AMS-C）评分来评估AMS。对所有志愿者的心率（HR）和血氧饱和度（SpO）进行临床监测。
与基线值（3.8±0.4毫米）相比，高海拔地区的平均ONSD（4.6±0.3毫米，p<0.05）显著增加，并且在整个高海拔暴露期间一直保持增大。ONSD的这种变化与AMS（AMS-C，r=0.26，p=0.37；LL，r=0.21，p=0.48）、高海拔头痛（r=0.54，p=0.046）以及SpO（r=0.11，p=0.72）和HR（r=0.22，p=0.44）的临床参数均无相关性。ONSD增加与描述高海拔地区ODE的视盘关键立体测量参数改变无关（r<0.1，p>0.5）。
高海拔暴露会导致视神经出现明显水肿，且与AMS无关。ONSD增加和ODE反映了高海拔地区缺氧驱动的视神经水肿形成，为高海拔疾病的发展及未来研究提供了重要的病理生理学见解。
