Glutamate levels in aqueous humor of patients with retinal artery occlusion.

Abstract

We analyzed the levels of glutamate and other amino acids in aqueous humor of patients with retinal artery occlusion (RAO) to determine whether glutamate is associated with retinal ischemia in RAO. Aqueous humor samples were obtained from nine RAO patients by paracentesis performed as an emergent therapeutic intervention and from nine cataract patients without other ocular disease who served as controls. Aspartic acid, glutamate, taurine, and alanine concentrations were determined using high-performance liquid chromatography. The glutamate level in aqueous humor of patients with RAO (4.46 +/- 1.62 micromol/L) was significantly higher than that in controls (2.98 +/- 1.12 micromol/L) (P < 0.05). Elevated glutamate levels in aqueous humor may indicate diffusion of vitreous glutamate released from the damaged retina due to acute retinal ischemia in RAO. An increase in the extracellular glutamate level may play an important role in ischemic retinal damage in RAO.