Abstract
Purpose :
Coffee, tea and the majority of non-alcoholic energy drinks contain caffeine. In an earlier study (ARVO 2014) it has been shown that the consumption of a 250 ml of RedBull induces a significant decrease of the blood volume and blood oxygenation in the capillaries of the optic nerve papilla in humans. It was suggested that this effect may be caused by the caffeine content of this drink. The objective of the present study was to determine the direct effect of the caffeine on the blood oxygenation in capillary structures of the eye optic nerve papilla.
Methods :
Fifteen university healthy students, non-smokers, aged from 23 to 29 years (24, 8±2, 7) have participated in this study. The blood volume and oxygenation at the level of the capillaries structures of the optic nerve have been assessed using a multichannel spectroscopy technique (Diaconu 2010). Other systemic parameters that can influence the optic nerve’s blood oxygenation rate were also monitored: the brachial blood pressure (BPA), the heart rate (HR) and the systemic arterial blood oxygenation (SpO2). A first series of measurements were performed before ingesting a pill containing 200 mg of caffeine, considered as baseline values for each subject. Other measures have followed immediately after the pill ingesting (T0), and for 15 (T15), 30 (T30), 45 (T45), 60 (T60), 75 (T75) and 90 (T90) minutes.
Results :
The blood oxygenation in the optic nerve capillaries structures has decreased by 12% (p < 0.001), and the blood volume decreased by 23.3% (p < 0.001) 30 minutes after the caffeine ingestion. The blood volume and oxygenation have remained low compared with the initial state, even 90 minutes after the caffeine ingestion.
Conclusions :
The caffeine is a powerful vasoconstrictor which affects the blood flow of the capillary structures in the optic nerve area of young healthy people. The caffeine effect in combination with a blood oxygenation mapping technique may be a useful procedure to detect the atrophic zones of the optic nerve papilla of glaucoma patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.