Physiology and Pharmacology Spectrophotometric Retinal Oximetry in Pigs

Citation: Traustason S, Kiilgaard JF, Karlsson RA, Hardarson SH, Stefansson E, la Cour M. Spectrophotometric retinal oximetry in pigs. Invest Ophthalmol Vis Sci. 2013;54:2746–2751. DOI:10.1167/ iovs.12-11284 PURPOSE. To assess the validity of spectrophotometric retinal oximetry by comparison to blood gas analysis and intravitreal measurements of partial pressure of oxygen (pO2). METHODS. Female domestic pigs were used for all experiments (n 1⁄4 8). Oxygen fraction in inspired air was changed using a mixture of room air, pure oxygen, and pure nitrogen, ranging from 5% to 100% oxygen. Femoral arterial blood gas analysis and retinal oximetry were performed at each level of inspiratory oxygen fraction. Retinal oximetry was performed using a commercial instrument, the Oxymap Retinal Oximeter T1. The device simultaneously acquires images at two wavelengths (570 nm and 600 nm), and specialized software automatically detects retinal blood vessels. In three pigs, invasive pO2 measurements were performed after the initial noninvasive measurements.