Bosch and colleagues1 performed a very nice study of corneal thickness at high altitude. However, some statements may benefit from clarification. Specifically, “Besides AMS [acute mountain sickness], corneal changes during high-altitude climbs may also be a dangerous hazard owing to a potential significant decrease in visual acuity. The often-quoted experience of Dr Beck Weathers, a Mount Everest climber who had undergone radial keratotomy prior to ascent and incurred severe vision loss during the climb, is such an example.” The authors correctly imply that corneal thickening plays a major role in radial keratotomy visual changes at high altitude. However, the mechanism of these changes is a bit more complicated and warrants a more precise explanation.
Mader TH, White LJ. Corneal Thickness Changes in Very-High-Altitude Mountaineers. Arch Ophthalmol. 2010;128(9):1224-1225. doi:10.1001/archophthalmol.2010.175