High-Altitude Retinal Hemorrhage (HARH) Observed on the Kyoto University 1990 (KUMREX'90) .

Abstract

Kyoto University Medical Research Expedition to Xixabangma 1990 (KUMREX'90) carried up a retino-camera (CR4-45NM, CANON) to the Base Camp (BC 5, 020m) of Mt. Xixabangma (8, 027m) to observe the incidence of the high altitude retinal hemorrhage (HARH) . As the result, very high incidence of HARH among Himalayan-Newcomer (NC) s was observed. Binocular HARHs were observed among 90% of NCs climbed above 6, 000m. Whereas it was observed only among 53% (monocular) (binocular; 21%) of Himalayan-Experienced (HE) s climbed to the top. About 80% of NCs revealed mild HARH already on the arrival to BC, whereas only 13% of HEs did it. None of them with HARH complained any symptoms. This phenomenon seems to be not illness but normal human response to high altitude.