title: Visible light optical coherence tomography measures retinal oxygen metabolic response to systemic oxygenation.
abstract: The lack of capability to quantify oxygen metabolism noninvasively impedes both fundamental investigation and clinical diagnosis of a wide spectrum of diseases including all the major blinding diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Using visible light optical coherence tomography (vis-OCT), we demonstrated accurate and robust measurement of retinal oxygen metabolic rate (rMRO2) noninvasively in rat eyes. We continuously monitored the regulatory response of oxygen consumption to a progressive hypoxic challenge. We found that both oxygen delivery, and rMRO2increased from the highly regulated retinal circulation (RC) under hypoxia, by 0.28 ± 0.08 μL min-1(p< 0.001), and 0.20 ± 0.04 μL min-1(p< 0.001) per 100 mmHg systemic pO2reduction, respectively. The increased oxygen extraction compensated for the deficient oxygen supply from the poorly regulated choroidal circulation. Results from an oxygen diffusion model based on previous oxygen electrode measurements corroborated ourin vivoobservations. We believe that vis-OCT has the potential to reveal the fundamental role of oxygen metabolism in various retinal diseases.
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Ji
authors.initials: J
authors.lastname: Yi
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Siyu
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Vadim
authors.initials: V
authors.lastname: Backman
authors.affiliation: McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705, USA.
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
authors.affiliation: McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Sorenson
authors.affiliation: Department of Ophthalmology, Northwestern University, Chicago Illinois 60611, USA.
authors.forename: Amani A
authors.initials: AA
authors.lastname: Fawzi
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA ; Department of Ophthalmology, Northwestern University, Chicago Illinois 60611, USA ; Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Linsenmeier
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA ; Department of Ophthalmology, Northwestern University, Chicago Illinois 60611, USA.
authors.forename: Hao F
authors.initials: HF
authors.lastname: Zhang
keywords: oxygen metabolism; retinal circulation; visible light optical coherence tomography