Measurement of preretinal oxygen tension in the vitrectomized human eye using fluorine-19 magnetic resonance spectroscopy.

We obtained oxygen measurements from a human eye that contained small preretinal droplets of perfluorotributylamine (FTBA) by using fluorine-19 magnetic resonance spectroscopy. These droplets were the remainder of a larger volume of FTBA that was used as an intraoperative retinal tamponade during retinal detachment repair. The spin-lattice relaxation rate ([T1]-1) of the FTBA fluorine nuclide was obtained that could then be related, by direct proportionality, to droplet PO2. With the patient in a supine position, the droplets could be positioned over the macula in the preretinal vitreous space, whereon the FTBA PO2 could be influenced by the preretinal oxygen concentration. Preretinal PO2 values, derived from magnetic resonance spectroscopy, were in the range of 6 to 9 mm Hg, although multiple components were identified that were suggestive of a heterogeneous distribution of PO2 values in the population of droplets. To our knowledge, this investigation is the first to demonstrate the feasibility of this approach to performing long-term, noninvasive preretinal oxygen measurements in the vitrectomized human eye by using small droplets of a liquid perfluorochemical.