Purchase this article with an account.
Akbar Shakoor, Norman P. Blair, Marek Mori, Mahnaz Shahidi; Chorioretinal Vascular Oxygen Tension Changes in Response to Light Flicker. Invest. Ophthalmol. Vis. Sci. 2006;47(11):4962-4965. doi: 10.1167/iovs.06-0291.
Download citation file:
© 2015 Association for Research in Vision and Ophthalmology.
purpose. To investigate oxygen tension (Po 2) changes in the retinal and choroidal vasculatures in response to visual stimulation by light flicker.
methods. A previously developed optical section phosphorescence imaging system was used to measure Po 2 separately in the retinal veins, arteries, and capillaries and in the choroid before and during light flicker. Imaging was performed in rats during light flicker at frequencies between 0 and 14 Hz. Light flicker–induced changes in the chorioretinal vasculature Po 2 and arteriovenous Po 2 differences were determined. Retinal arterial and venous Po 2 were measured along blood vessels as a function of the distance from the optic nerve head.
results. Retinal arterial Po 2 and arteriovenous Po 2 differences increased with increasing light flicker at frequencies up to 10 Hz, after which no further increase was observed. Significant increases in retinal arterial Po 2 (P = 0.009; n =10) and in retinal capillary Po 2 (P = 0.04, n = 10) were measured in response to light flicker at 10 Hz. Retinal arteriovenous Po 2 differences during light flicker were significantly greater than differences before light flicker (P = 0.01; n = 10). Retinal arterial Po 2 decreased significantly with increased distance from the optic nerve head (P ≤ 0.004), whereas retinal venous Po 2 remained relatively unchanged (P ≥ 0.4).
conclusions. Measurement of changes in the chorioretinal vasculature Po 2 can potentially advance the understanding of oxygen dynamics in challenged physiological states and in animal models of human retinal diseases.
This PDF is available to Subscribers Only