• Online Features  This Article  • Full text  • PDF  • Reply to article  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Citing articles on Web of Science (4)  • Contact me when this article is cited  Related Content  • Related letter  • Similar articles in this journal  Topic Collections  • Corneal Disorders  • Alert me on articles by topic  Social Bookmarking   What's this?

Martina Monika Bosch, MD; Daniel Barthelmes, MD; Tobias Michael Merz, MD; Pascal Bruno Knecht, MD; Frederic Truffer, MSc; Konrad E. Bloch, MD; Michael A. Thiel, MD, PhD; Benno L. Petrig, DSc; Alexander J. Turk, MD; Otto D. Schoch, MD; Urs Hefti, MD; Klara Landau, MD

Arch Ophthalmol. 2010;128(2):184-189. doi:10.1001/archophthalmol.2009.385

Objective  To investigate the effect of very high altitude and different ascent profiles on central corneal thickness (CCT).

Methods  Twenty-eight healthy mountaineers were randomly assigned to 2 different ascent profiles during a medical research expedition to Mount Muztagh Ata (7546 m) in western China. Group 1 was allotted a shorter acclimatization time prior to ascent to 6265 m. The main outcome measure was CCT. Secondary outcome measures were oxygen saturation (SpO₂) and symptom assessments of acute mountain sickness (cerebral acute mountain sickness score). Examinations were performed at 490, 4497, 5533, and 6265 m.

Results  Central corneal thickness increased in both groups with increasing altitude and decreased after descent. In group 1 (with the shorter acclimatization), mean CCT increased from 537 to 572 μm. Mean CCT in group 2 increased from 534 to 563 μm (P = .048). The amount of decrease in SpO₂ paralleled the increase in CCT. There was no significant decrease in visual acuity. There was a significant correlation between CCT and cerebral acute mountain sickness score when controlled for SpO₂ and age.

Conclusions  Corneal swelling during high-altitude climbs is promoted by low SpO₂. Systemic delivery of oxygen to the anterior chamber seems to play a greater role in corneal oxygenation than previously thought. Adhering to a slower ascent profile results in less corneal edema. Visual acuity in healthy corneas is not adversely affected by edema at altitudes of up to 6300 m. Individuals with more acute mountain sickness–related symptoms had thicker corneas, possibly due to their higher overall susceptibility to hypoxia.

Author Affiliations: Department of Ophthalmology (Drs Bosch, Barthelmes, Knecht, and Landau), and Pulmonary Division (Drs Bloch and Turk), University Hospital Zurich, Zurich, Switzerland; Department of Intensive Care Medicine, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland (Dr Merz); Institut de Recherche en Ophthalmologie, Sion, Switzerland (Mr Truffer and Dr Petrig); Center for Integrative Human Physiology, University of Zurich, Zurich (Dr Bloch); Department of Ophthalmology, State Hospital Lucerne, Lucerne, Switzerland (Dr Thiel); Department of Pneumology, State Hospital St Gallen, St Gallen, Switzerland (Dr Schoch); and Department of Surgery, State Hospital Liestal, Liestal, Switzerland (Dr Hefti).

CiteULike    Connotea    Delicious    Digg    Facebook    Reddit    Technorati    Twitter     What's this?

RELATED LETTER

Corneal Thickness Changes in Very-High-Altitude Mountaineers
Thomas H. Mader and Lawrence J. White
Arch Ophthalmol. 2010;128(9):1224-1225.
EXTRACT | FULL TEXT  

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Corneal Thickness Changes in Very-High-Altitude Mountaineers
Mader and White
Arch Ophthalmol 2010;128:1224-1225.
FULL TEXT  

Corneal Thickness Changes in Very-High-Altitude Mountaineers--Reply
Bosch et al.
Arch Ophthalmol 2010;128:1225-1225.
FULL TEXT