Retinal vein occlusion in high altitude.

Staying at high altitude has been reported to be associated with thrombosis in lowlanders. We report 3 cases of retinal vein occlusion in high altitude. Two were males 31 and 37 years of age, who developed nonischemic central retinal vein occlusion while staying at high altitude. The former developed central retinal vein occlusion after 90 days at 6309 m, while the latter was affected at an altitude of 3353 m where he had been for the past 1 year and had recurrence of central retinal vein occlusion in the other eye on re-entry to the same altitude. The third case is that of a 40-year-old female who developed inferotemporal branch retinal vein occlusion on the second day after entry into high altitude (3353 m) by air, while ascending further in a vehicle at an altitude of approximately 4572 m. All three did not have any systemic disease and showed complete recovery on descent to a lower altitude.