AQP0, AQP1, AQP4, and AQP9 proteins have all been found in mammalian retina [11–14], but it is the AQP4 channel that has been localized to the Müller cell endfeet in rats [11,13] and chicks [15] and has been linked to the redistribution and absorption of ischemia-induced edema in the retina and brain [16–19]. This evidence concerns the gene AQP4 and ischemia.