gms | German Medical Science

Background: Tissue hypoxia plays a central role in such widespread diseases as diabetes mellitus and cerebral infarction. But also due to rising numbers of mountaineers and trekkers, who easily reach high altitudes these days, hypoxia research and high-altitude-physiology as classic research areas gain ever more attention. From the literature a systemic up-regulation of e.g. HIF-1α und VEGF are known under hypoxia. Since the retinal vasculature as analogue of cerebral vasculature is fairly easy to image in vivo, we intended to describe the influence of high-altitude onto the retina for the first time using fluorescein angiography (FLA) and optical coherence tomography (OCT).

Methods: During the Tübingen High Altitude Ophthalmology (THAO)-study 14 healthy volunteers reached the Capanna Margherita (CM) in the Swiss/Italian Alps (4,559 m asl) after one night at the Rif. Gnifetti (3,611 m asl). FLAs, fundus fotos, and OCTs were performed prior, on day 2 of, and ≥2 weeks post high-altitude exposure.

Results: FLA and OCT results were completely normal prior and post exposure. One day after arrival at CM 7 volunteers showed peripheral dye leakage in the temporal peripheral retina, mostly temporally-inferiorly. Only one volunteers showed a retinal hemorrhage which resolved over weeks. OCT examinations showed no alteration during exposure to high altitude. There was no correlation with signs of acute mountain sickness.

Conclusions: For the first time retinal leakages could be shown under high-altitude exposure; similar reactions are likely to appear in other systems (e.g. cerebral) under hypoxic conditions and are subject of further investigations. High-altitude exposure should be considered carefully in patients suffering from ocular conditions with neovascular component.