Retinal hemorrhages are common above 5200 m (17,000 ft) and are not usually associated with acute mountain sickness (AMS). High-altitude retinal hemorrhages (HARHs) are rarely symptomatic, but if found over the macula, these hemorrhages may cause temporary blindness. The diagnosis can be established by ophthalmoscopy. Without visualization of the lesion, the differential diagnosis of unilaterally decreased vision or blindness at high altitude includes migraine equivalent, cerebrovascular accident, and dry eye (often unilateral, due to strong winds), as well as all conditions found at sea level.
Management and Disposition
HARHs generally resolve spontaneously after descent to lower altitude. No treatment is necessary for asymptomatic HARH. Patients with HARH associated with a decrease in vision should be referred to an ophthalmologist for follow-up.
Patients with blurred vision and unilateral mydriasis at the high altitude should be asked about use of medications, including transdermal scopolamine patches.
As with almost all altitude-related problems, descent is the primary treatment. This is not emergent unless associated with severe altitude illness or progressive visual loss.
Although most symptomatic HARHs resolve completely in 2 to 8 weeks, cases of permanent paracentral scotomata have been reported.
High-Altitude Retinal Hemorrhage. Fundoscopic appearance of high-altitude retinal hemorrhage. (Photo contributor: Peter Hackett, MD.)