High altitude retinal hemorrhage.

The accessibility of high-altitude areas presents the risk of high altitude retinal hemorrhages (HARH). Four cases reported illustrate localized macular, diffuse, and familial incidence of HARH. Fluorescein angiography indicated no leakage, and a superficial retinal location of the hemorrhages. Marked retinal artery and vein dilation occurs. Ophthalmodynamometry showed retinal vascular hypertension in the presence of HARH. The complete resolution of hemorrhages occurs in most cases. Despite the return of visual acuity to normal, visual function studies indicate the persistance of defects.