It is important to note that in humans, although elevated vitreous glutamate levels are not consistently observed in glaucoma patients [49,50], a decline in glutamate transporter expression with age, GLAST in particular, may predispose the individual to excitotoxic damage [51,52], suggesting that the reduced function of glutamate transporters may contribute to the pathogenesis of glaucoma. This evidence concerns the gene SLC1A3 and glaucoma.