Abstract
Purpose :
Oxygen consumption at the ocular surface determines and indicates important physiology. We aimed to use a novel optrode (optical “electrode”) to directly measure oxygen uptake and monitor its dynamics with high spatial and temporal resolution at ocular surface.
Methods :
Experiments were performed on isolated whole eyes from male mice or male Sprague-Dawley rats. The spatial O2 flux profile of cornea was measured by optrode system (PreSens), in cornea center, periphery, limbus and conjunctiva. Cornea wounds were made by scraping off approximately 1.5–2 mm2 of epithelium with an ophthalmologic scalpel. O2 flux were also measured spatially, in wound center, wound edge and wound side, as well as temporally, during wound healing process. ANOVA and two-tailed Student’s t-test were used for statistical analysis.
Results :
The optrode is able to detect significantly different O2 influxes at rat cornea center, limbus and conjunctiva of -33.41±3.89, -64.3±4.32 and -66.67 ±1.30 pmol/cm2/s, respectively; and at mice cornea center, periphery, limbus and conjunctiva of -34.73±7.60, -47.91±6.44, -67.28±5.35 and -55.92 ±9.06 pmol/cm2/s, respectively. After wounding, the wound center and wound edge showed significant decrease in O2 influxes, while wound side away from wound showed similar influx magnitude. O2 influxes changed gradually during wound healing process.
Conclusions :
Using optrode, we demonstrated significant heterogeneity in O2 flux at the ocular surface. Limbus region showed higher O2 uptake than cornea center and periphery. Wounding reduced the O2 influxes at the wound center and wound edge, but not at the intact surface of wound side. The optrode maps O2 fluxes with high spatial and temporal resolution, which may offer a novel technique with promising potential for both laboratory research and clinical application to characterize cornea physiology and pathology.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.