Retinal vessel diameters in relation to hematocrit variation during acclimatization of highlanders to sea level altitude
Research output: Contribution to journal › Journal article › Research › peer-review
PURPOSE: To examine variations in retinal vessel diameters during acclimatization of native highlanders to normobaric normoxia at sea level. METHODS: Fifteen healthy residents of the greater La Paz region in Bolivia (3600 m above sea level) were examined thrice over a 72-day period, after having traveled by airplane to Copenhagen, Denmark, near sea level. RESULTS: In the study subjects, hematocrit decreased from 49.6% (day 2) to 45.9% (P = 0.0066, day 23) and 41.7% (P <0.0001, day 72); from days 2 to 23, retinal vein diameter increased by 2.68% (P = 0.0079); whereas retinal artery and vein diameters were indistinguishable from baseline after 72 days. No funduscopic signs of retinopathy were observed. Arterial blood pressure remained stable throughout the study. CONCLUSIONS: Although a 16% reduction in hematocrit occurred between days 2 and 72 after arrival at sea level, the only significant excursion observed was that the diameter of the veins was larger at day 23 than at days 2 and 72. Retinal vessel diameters demonstrated a wide homeostatic range during acclimatization-driven hematocrit variation.
Original language | English |
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Journal | Investigative Ophthalmology & Visual Science |
Volume | 50 |
Issue number | 8 |
Pages (from-to) | 3960-3 |
Number of pages | 4 |
ISSN | 0146-0404 |
DOIs | |
Publication status | Published - 1 Aug 2009 |
Bibliographical note
Keywords: Acclimatization; Adult; Altitude; Blood Pressure; Electroretinography; Female; Hematocrit; Humans; Intraocular Pressure; Male; Oxygen; Retinal Vessels; Visual Acuity
ID: 20648907