Vitreous Amino Acid Concentrations in Patients With Glaucoma Undergoing Vitrectomy

Abstract

To measure vitreous concentrations of glutamate and other amino acids in patients with glaucoma undergoing vitrectomy.

Evaluation of corpus geniculatum laterale and vitreous fluid by magnetic resonance spectroscopy in patients with glaucoma; a preliminary study

“…It is a leading cause of blindness worldwide, and is also described as one of the preventable causes of blindness if diagnosed early. 1 The progressive damage in the visual fields of some patients with normal or controlled intraocular pressure (IOP) proves that the IOP is not only the cause of glaucoma, but is also an important risk factor for it. 2 The importance of both the anterograde and retrograde neurotransmitter passage between the axons of the lateral geniculate body (LGB) and the retinal ganglion cells in maintaining the vital functions of the retinal ganglion cells is well known.…”

“…3 Glutamate is an important transmitter existing widely in the central nervous system (CNS) and is responsible for excitatory transmission. 1,[4][5][6] Its neurotoxic effect (excitotoxicity) was first seen through experimental studies on mice. 4 In further studies, it was determined that glutamate may be effective in the pathogenesis of some neurodegenerative diseases of CNS.…”

“…7 Some studies reported an increase in the glutamate level, 7 while others claimed no increase in glutamate. 1 However, neuroexcitoxicity was shown histopathologically in the experimental glaucoma models. 5 Thus, recent studies have mainly concentrated on searching for the remediation role of antiexcitoxic agents, such as memantine, and most of these studies have revealed that memantine is an effective agent for the treatment of experimental glaucoma.…”

Glutamate excitotoxicity in glaucoma: truth or fiction?

“…In some cases, such studies may be more important to the scientific community than positive studies. At the very least, this study significantly adds to the body of evidence that there is no elevation of vitreal glutamate in patients with glaucoma 19 or in animal models of glaucoma. 18 It suggests the need to re-evaluate carefully the potential role of glutamate excitotoxicity in glaucoma.…”

“…17 Based on these reports of elevated vitreal glutamate, glutamate excitotoxicity has been proposed to contribute to the ganglion cell death which is fundamental to glaucoma. 1 However, neither a larger study of vitreal glutamate concentration in monkeys with experimental glaucoma 18 nor a further study of vitreal glutamate levels in humans 19 could replicate Dr Dreyer's findings. 16 What is even more surprising are the results of the current study by Kwon et al Elevated vitreal glutamate levels were not found in a primate model of central retinal artery occlusion.…”