Les mécanismes d’oxygénation sanguine de l’œil en corrélation avec le système respiratoire
Abstract Oxygen is an integral part of the environment. It has a major role to play in the cellular structures of the human body.  The two systems, which are closely related to the distribution of oxygen within the body are the cardiovascular and the respiratory systems.  The transparency of the eye can be used as a way to non-invasively measure the concentration of oxyhemoglobin in the blood which feeds the central nervous system. The capillary oxygenation of the eye was measured using multichannel spectro-reflectometry technology.  Two areas of the eye were studied: the capillaries of the optical nerve which represent retinal circulation as well as the capillaries of the eye at the corneal limbus. Five healthy non-smoking volunteers aged 20-45 years and five healthy smoking volunteers aged 20-40 years took part in this study. All subjects were exposed to hypo and hyper oxygenation conditions.  The experimental session was composed of a continuous recording of 360 seconds.  In the first 60 seconds, volunteers breathed ambient air, followed by a second phase of 180 seconds during which the subjects were either exposed to a condition of hyper (60% O2) or hypo oxygenation (15% O2).  The final phase of the experimental session was an exposure to ambient air.  Cardiac rhythm and arterial oxygenation were measured at the tip of the finger with a sphygmo-oxymeter. Clearly, variations in the oxyhemoglobin blood concentration in the capillaries of the optic nerve or the sclerotic are always directly correlated with variations in the arterial oxyhemoglobin levels.  However, the optic nerve capillaries offer more precision for measurements of oxygenation as compared to the sclerotic capillaries.  In this study, accurate information has been provided on the oxyhemoglobin concentration using spectro-reflectometry of the eye. This technology could become a tool in the diagnosis of various pulmonary or ocular pathologies.
spectro-reflectometry