Related Experiment Video
Updated: Jan 25, 2026

Measurement of Energy Metabolism in Explanted Retinal Tissue Using Extracellular Flux Analysis
Published on: January 7, 2019
Relating glaucomatous visual field loss to retinal oxygen delivery and metabolism
Ahmad A Aref1, Shervin Maleki2, Ou Tan3
1Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
Purpose:
To test the hypothesis that visual field (VF) loss is associated with decreased retinal blood flow, oxygen delivery and metabolism, and with increased retinal oxygen extraction fraction (OEF) in glaucomatous individuals.
Methods:
Glaucomatous subjects underwent automated perimetry, dual wavelength scanning laser ophthalmoscopy and Doppler optical coherence tomography imaging in order to measure mean deviation, central retinal arterial and venous diameter equivalents (CRAE and CRVE), oxygen saturation levels and total retinal blood flow (TRBF), respectively. Retinal oxygen delivery, metabolism and extraction fraction were derived from measurements of oxygen saturation and blood flow.
Results:
Twenty eyes of 14 subjects were included in the study. Mean deviation was on average -13.76 ± 8.70 dB. Mean CRAE and CRVE were 126 ± 28 and 191 ± 35 μm, respectively. Mean TRBF and oxygen delivery were 34.3 ± 11.7 μl/min and 6.5 ± 2.6 μl O2 /min, respectively. Mean oxygen metabolism and extraction fraction were 2.1 ± 0.94 μl O2 /min and 0.34 ± 0.15, respectively. Visual field (VF) loss was associated with reduced CRAE and CRVE, TRBF and oxygen delivery and associated with increased OEF.
Conclusion:
Combined measurements of retinal blood flow and oxygen saturation in glaucomatous individuals suggest VF loss is associated with impaired oxygen delivery and augmented OEF.
Related Concept Videos
Line Loss
Line loss impacts power delivery efficiency in a balanced three-phase circuit. The symmetry in such a circuit simplifies the...
What is Metabolism?
Reducing Line Loss
With a step-up transformer at the source, the voltage is increased, thereby reducing the current in the transmission lines since power loss in...
Relative Risk
Major Losses in Pipes
Fluid flow can be classified as laminar or turbulent, primarily based on the Reynolds number. This dimensionless number reflects the relative influence of inertial to viscous...
Minor Losses in Pipes
Valves play a significant role in generating minor losses by obstructing or redirecting the fluid flow. When a valve is closed or partially closed, it restricts the flow...

