Retinal haemorrhage in Himalayan mountaineers.

The fundi of 14 climbers were monitored on ascent to 6000 metres over a 15 day period in the Nepal Himalaya. A total of 4 climbers experienced symptomless haemorrhages. These haemorrhages were not secondary to changes in haemoglobin concentration, nor did they appear correlated to the use of acetazolamide. The risk of developing retinal haemorrhage was, however, significantly greater in the better acclimatized individuals. Possible reasons for this relationship are discussed.