Ethics of parsimonious medicine: Reply

摘要

To the Editor: Exposure to high altitude can cause acute mountain sickness (AMS) and, in severe cases, cerebral or pulmonary edema. Capillary leakage has been hypothesized to play a role in the pathogenesis of AMS, although the mechanism of altitude-related illnesses remains largely unknown. As a direcdy observable part of the brain, the retina offers a window to study altitude-related vascular changes of the central nervous system. High-altitude retinopathy is characterized by optic disc edema, retinal hemorrhages, cotton wool spots, and increased tortuosity and dilation of retinal vessels. Vessel leakage in the retinal periphery has not been investigated. Our objective was to assess retinal vessel integrity at high altitude using fluorescein angiography.Methods. Fourteen healthy, unacclimatized volunteers (7 male and 7 female white participants aged 25-54 years; mean [SD] age, 35 [4] years) were recruited from the University of Tubingen by mass e-mail and studied at baseline (341 m), after ascent to 4559 m within 24 hours, and more than 14 days after return by fluorescein angiography with a confo-cal scanning laser ophthalmoscope (Spectralis, Heidelberg Engineering). Photographs were independently graded in random order by 4 masked ophthalmologists for presence and location of leakage.