PERFLUORINATED ORGANIC LIQUID AS AN INTRAOCULAR OXYGEN RESERVOIR FOR THE ISCHEMIC RETINA

Purpose. Liquid perfluorocarbons are used as temporary vitreous substi tutes in the surgical management of complicated retinal detachment. Th e purpose of this study was to determine if physiologic benefits could also be derived from the high oxygen solubility of perfluorochemicals relative to vitreous, especially during retinal ischemia. Methods. Th e normal vitreous humor of the rabbit eye was replaced with either per fluorotributylamine (FTBA) or balanced salt solution (BSS). Retinal is chemia was then induced by increasing the intraocular pressure above t he peak systolic blood pressure for intervals of 10, 30, or 90 minutes . Results. Over a 10- or 30-minute period of ischemia, during which el ectroretinographic (ERG) responses were recorded, FTBA-filled eyes and BSS-filled eyes showed decreases in the a- and b-wave amplitudes. How ever, wave amplitudes were significantly greater in FTBA-filled eyes a t most times examined (P < .05). ERG responses were maintained through out a 30-minute ischemic interval in oxygenated FTBA-filled eyes, but not in oxygenated BSS or deoxygenated FTBA-filled eyes. When examined 1 day after a 90-minute interval of ischemia, oxygenated FTBA-filled e yes maintained 45% and 57% of the preischemic ERG a- and b-wave amplit udes, respectively, compared to a 5% and 3% retention of wave amplitud es in oxygenated BSS filled eyes. On light microscopic examination of these eyes, FTBA-exposed retinas showed less ischemic damage than BSS- exposed retinas. Conclusions. When used as a vitreous substitute, FTBA exerts a neuroprotective effect on the ischemic retina that appears t o relate to an increased retinal oxygen supply compared to BSS.