In vivo O2 consumption in rhesus monkeys in light and dark.

The rate of oxygen consumption in retinas in vitro has been measured in a great number of species, but in vitro estimates have varied partly because the rate of O2 uptake depends heavily upon the composition of the buffered solution used to maintain the retina. The in vitro experiments on frog retinas show a greater O2 consumption in dark than in light conditions, and indicate marked differences in metabolism between light and dark conditions. A method was developed to estimate retinal oxygen consumption in vivo. We evaluated the oxygen consumption of the in vivo Rhesus monkey retina with an intraocular oxygen microelectrode. The intact monkey retina consumes more oxygen in darkness than in light.