# Imaging of Retinal Oxygenation and Metabolism

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2020 · $475,045

## Abstract

Abstract
The retinal tissue requires an adequate supply of oxygen and nutrients to maintain normal metabolism and
function. Insufficient blood flow (ischemia) leads to reduced tissue oxygenation (hypoxia), development of
pathologies, and ultimately tissue loss. Hypoxia-triggered pathologies can cause visual impairment in many
retinal diseases, including vascular occlusions, diabetic retinopathy, retinopathy of prematurity, age-related
macular degeneration, and glaucoma. Several factors, including vascular malperfusion, oxygen supply to
demand adequacy, tissue hypoxia, and impaired energy metabolism contribute to vision loss. In order to gain
knowledge of the relation among these factors, measurements of retinal oxygen delivery, oxygen extraction
fraction, tissue oxygen tension and oxygen metabolism are required. Indeed, a combined and correlative
evaluation of these key retinal oxygen metabolic-related parameters (oxygen delivery, oxygen extraction
fraction, tissue oxygen tension, oxygen metabolism) is essential to understand the role of oxygen deficiency in
the development of vision-threatening pathologies. The objective of the research project is to advance
knowledge of retinal disease pathophysiology by a comprehensive and innovative investigation of retinal
oxygen dynamics with the use of novel imaging technologies. The specific aims are to: 1) identify retinal
oxygen metabolic-related parameters measured immediately after ischemia that can predict subsequent tissue
outcomes; 2) elucidate compensatory capacities and consequent susceptibility of diabetic retina to impaired
oxygen metabolism; 3) establish a threshold for retinal tissue injury based on the relation of the level and
duration of ischemia to subsequent tissue outcomes; 4) determine alterations in edematous retinal tissue
oxygenation and its response to light flicker-induced increased metabolic activity. The findings will impact the
field by identifying clinically translatable markers to improve diagnostic/prognostic evaluation of retinal vascular
occlusions, diabetic retinopathy and macular edema, as well as, propel development of
preventative/therapeutic procedures that can successfully combat vision loss, thus improving the quality of life
and reducing the cost of caring for the visually impaired.

## Key facts

- **NIH application ID:** 9852444
- **Project number:** 5R01EY017918-13
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** Mahnaz Shahidi
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $475,045
- **Award type:** 5
- **Project period:** 2007-09-01 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9852444

## Citation

> US National Institutes of Health, RePORTER application 9852444, Imaging of Retinal Oxygenation and Metabolism (5R01EY017918-13). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9852444. Licensed CC0.

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