AJP - Heart and Circulatory Physiology, Vol 256, Issue 4 1127-H1133, Copyright © 1989 by American Physiological Society
Intraocular oxygen tension measured with a fiber-optic sensor in normal and diabetic dogs
E. Stefansson, J. I. Peterson and Y. H. Wang
Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710.
A new fiber-optic O2 sensor was used to measure the O2 tension in the
living dog eye, and the results were compared with simultaneous O2 tension
measurements with polarographic electrodes. The fiber-optic sensor and the
polarographic electrodes gave similar readings of anterior chamber O2
tension and gave an identical response to elevation of inspired O2 levels.
In the preretinal vitreous, the fiber-optic probe measured the O2 tension
26 +/- 5 mmHg (means +/- SD, n = 5), whereas the polarographic electrode
showed 23 +/- 7 mmHg (means +/- SD, n = 5) in the contralateral eyes.
Breathing 100% O2 raised the preretinal O2 tension similarly with both
systems. Preretinal O2 tension was measured with the fiber-optic sensor in
seven alloxan diabetic dogs and was 26 +/- 7 mmHg, which is not
significantly different from normal dogs. The fiber-optic sensor has some
advantages over the polarographic electrodes. The fiber-optic sensor does
not consume O2 and is not dependent on the diffusion characteristics of the
medium or changes due to stirring or fluid currents.
