Department of Ophthalmology, Rassoul Akram Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Graefes Arch Clin Exp Ophthalmol. 2013 Jan;251(1):123-7. doi: 10.1007/s00417-012-2050-4. Epub 2012 May 9.
To study intraocular pressure (IOP) alteration in healthy individuals following a rapid effortless increase in altitude from 1900 m above sea level (ASL) to 3740 m ASL.
Intraocular pressure, blood pressure, pulse rate, and arterial oxygen tension were determined in both eyes of healthy volunteers at the lower altitude. Participants were taken to a higher altitude of 3740 m ASL (1840-m altitude gain) via gondola lift, which took 30 minutes. All measurements were repeated at the higher altitude. Pearson and Spearman correlation analysis was conducted to assess the correlations among the variables. A paired t-test and linear regression were also used to compare IOP before and after ascending. The accepted level of significance for all tests was p <0.05.
Fifty-four healthy volunteers participated in the study. Four eyes of three subjects with IOP higher than 21 mmHg were excluded. Intraocular pressure ± SD (range) decreased from 14.9 ± 2.6 mmHg (9-21 mmHg) to 14.3 ± 2.4 mmHg (11-20 mmHg) (p = 0.02) after the ascent. Arterial oxygen saturation decreased from 95.4 % to 91.5 % (p < 0.001). Neither of the participants complained of any ocular or systemic symptoms during or after ascending to the higher altitude. Mean IOP, before and after ascending, was positively correlated with systolic blood pressure before and after the increase in altitude (Pearson correlation coefficient, 0.41, p = 0.002 and Pearson correlation coefficient, 0.37, p = 0.006, respectively). Intraocular pressure changes did not correlate with age, pulse rate, or arterial oxygen saturation.
A rapid, effortless increase in altitude (over a moderate range in altitude) decreases IOP in healthy individuals. The observed decrease may not be clinically significant; however, it shows the versatility of IOP control mechanisms in response to alteration in altitude and temperature.
研究从海拔 1900 米上升到 3740 米的过程中，健康个体的眼压（IOP）变化。
在较低海拔处，通过缆车将健康志愿者的双眼眼压、血压、脉搏率和动脉血氧分压测量完毕。缆车 30 分钟即可到达海拔 3740 米的较高海拔处（海拔升高 1840 米）。在较高海拔处，所有测量结果都被重复。采用 Pearson 和 Spearman 相关分析评估变量之间的相关性。还使用配对 t 检验和线性回归来比较上升前后的 IOP。所有检验的置信水平均为 p <0.05。
54 名健康志愿者参与了研究。因眼压高于 21mmHg，3 名志愿者的 4 只眼被排除在外。眼压（±SD[范围]）从 14.9 ± 2.6mmHg（9-21mmHg）下降到 14.3 ± 2.4mmHg（11-20mmHg）（p = 0.02）。动脉血氧饱和度从 95.4%降至 91.5%（p <0.001）。在上升到较高海拔的过程中或之后，没有志愿者出现眼部或全身症状。上升前后的平均眼压与上升前后的收缩压呈正相关（Pearson 相关系数分别为 0.41，p = 0.002 和 Pearson 相关系数为 0.37，p = 0.006）。眼压变化与年龄、脉搏率或动脉血氧饱和度无关。
快速、轻松地升高海拔（适度海拔范围）会降低健康个体的眼压。观察到的下降可能没有临床意义；但是，它显示了眼压控制机制对海拔和温度变化的适应能力。
