The Effect of Hyperoxia and Hypoxia on Fluorescence Lifetime Imaging Ophthalmoscopy in Healthy Subjects- a Randomized, Double Blind, Crossover Study

The present study aims to investigate whether FLIO can also detect shorttime changes in retinal metabolism induced by hyperoxia and hypoxia. For this purpose, 48 healthy subjects will be included in the present study and changes in FLIO will be assessed during breathing of 100% oxygen to induce hyperoxia as well as during breathing of 12% oxygen in nitrogen to induce hypoxia. Since stimulation with flickering light also induces a higher metabolic demand in the retina (functional hyperemia), thisprovocation test will also applied during breathing of the different gas mixtures and compared to baseline. To gain information about retinal blood flow, optical coherence tomography angiography (OCT-A) will be performed. The results of the present study can help to gain more insight into the physiology of the retinal metabolism and might give grounds to establish new biomarkers in future studies.