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Updated: May 2, 2026

Retinal Pathophysiological Evaluation in a Rat Model
Published on: May 6, 2022
Inner retinal oxygen delivery and metabolism in streptozotocin diabetic rats
Justin Wanek1, Pang-Yu Teng, Norman P Blair
1Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois.
Purpose:
The purpose of the study is to report global measurements of inner retinal oxygen delivery (DO2_IR) and oxygen metabolism (MO2_IR) in streptozotocin (STZ) diabetic rats.
Methods:
Phosphorescence lifetime and blood flow imaging were performed in rats 4 (STZ/4 wk; n = 10) and 6 (STZ/6 wk; n = 10) weeks following injection of STZ to measure retinal arterial (O2A) and venous (O2V) oxygen contents and total retinal blood flow (F). DO2_IR and MO2_IR were calculated from measurements of F and O2A and of F and the arteriovenous oxygen content difference, respectively. Data in STZ rats were compared to those in healthy control rats (n = 10).
Results:
Measurements of O2A and O2V were not significantly different among STZ/4 wk, STZ/6 wk, and control rats (P ≥ 0.28). Likewise, F was similar among all groups of rats (P = 0.81). DO2_IR measurements were 941 ± 231, 956 ± 232, and 973 ± 243 nL O2/min in control, STZ/4 wk, and STZ/6 wk rats, respectively (P = 0.95). MO2_IR measurements were 516 ± 175, 444 ± 103, and 496 ± 84 nL O2/min in control, STZ/4 wk, and STZ/6 wk rats, respectively (P = 0.37).
Conclusions:
Global inner retinal oxygen delivery and metabolism were not significantly impaired in STZ rats in early diabetes.

