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Updated: Jul 17, 2026
Oxygen-Induced Retinopathy Model for Ischemic Retinal Diseases in Rodents
Published on: September 16, 2020
Chorioretinal vascular oxygen tension in spontaneously breathing anesthetized rats
A Shakoor1, M Gupta, N P Blair
1Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA.
Purpose:
To establish baseline and variability of oxygen tension (PO(2)) measurements in the choroid, retinal arteries, capillaries, and veins of spontaneously breathing anesthetized rats and determine the effect of a moderate surgical procedure on the chorioretinal PO(2).
Methods:
Our previously established optical section phosphorescence imaging technique was utilized to measure PO(2) in the chorioretinal vasculatures. Imaging was performed in 29 spontaneously breathing rats under ketamine/xylazine anesthesia. In 7 rats, blood was drawn using a surgically implanted femoral arterial catheter and analyzed to determine the systemic arterial PO(2). The PO(2) measurements in 22 rats without surgery (group 1) and 7 surgically instrumented rats (group 2) were statistically compared. The intrasubject variability was calculated by the average standard deviation (SD) of repeated measurements.
Results:
The average systemic arterial PO(2) was 52 +/- 7 mm Hg (mean +/- SD) in group 2. In group 1, the average PO(2) measurements in the choroid, retinal arteries, capillaries, and veins were 50 +/- 11, 40 +/- 5, 39 +/- 6, and 30 +/- 5 mm Hg, respectively. No statistically significant PO(2) differences in any of the chorioretinal vasculatures were found between the two groups (p > 0.4). The intrasubject variability was 3 mm Hg in the choroid, retinal arteries, capillaries, and veins.
Conclusions:
Chorioretinal PO(2) measurements in spontaneously breathing anesthetized rats have a relatively low variability, indicating that PO(2) changes due to various physiological alterations can be reliably assessed.
