title: Vitreous glutamate concentration and axon loss in monkeys with experimental glaucoma.
abstract: OBJECTIVE
  To evaluate vitreous glutamate concentration and axon loss in monkeys with experimental glaucoma.
  
  
  METHODS
  We induced unilateral chronic glaucoma by means of laser trabecular destruction in 14 rhesus and 6 cynomolgus monkeys. Intraocular pressure (IOP) was monitored weekly. We assessed optic nerve damage clinically and photographically. Vitreous, sampled immediately before enucleation, was analyzed for glutamate concentration by means of high-performance liquid chromatography. We quantified percentage of axon loss after histopathologic sectioning of the optic nerve, compared median glutamate concentration ratios, and assessed correlation of glutamate concentration, axon count, IOP, cup-disc ratio, duration of IOP elevation, and age.
  
  
  RESULTS
  Median vitreous glutamate concentration in glaucomatous eyes was 7.0 micromol/L (range, 3.0-88.6 micromol/L) vs 6.7 micromol/L (range, 2.8-87.4 micromol/L) in control eyes. The ratio (glaucomatous to control eyes) was 1.08. We found no significant correlation between vitreous glutamate concentration ratio and any of the other variables. The IOP, disc cupping, and axon loss were correlated.
  
  
  CONCLUSIONS
  We found no difference between vitreous glutamate concentration in glaucomatous and contralateral control monkey eyes when the entire data set was examined and no evidence of correlation between vitreous glutamate concentration and axon loss.
  
  
  CONCLUSIONS
  Vitreous concentration of the excitotoxic amino acid glutamate, thought to be associated with retinal ganglion cell death in glaucoma, was not altered in this study.
authors.affiliation: Department of Ophthalmology, University of Wisconsin Medical School, Madison 53792-3284, USA.
authors.forename: Sonja
authors.initials: S
authors.lastname: Wamsley
authors.forename: B'Ann T
authors.initials: BT
authors.lastname: Gabelt
authors.forename: David B
authors.initials: DB
authors.lastname: Dahl
authors.forename: Gary L
authors.initials: GL
authors.lastname: Case
authors.forename: Robert W
authors.initials: RW
authors.lastname: Sherwood
authors.forename: Christian A
authors.initials: CA
authors.lastname: May
authors.forename: M Rosario
authors.initials: MR
authors.lastname: Hernandez
authors.forename: Paul L
authors.initials: PL
authors.lastname: Kaufman
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology*; D002452:Cell Count; D002851:Chromatography, High Pressure Liquid; D002908:Chronic Disease; D004195:Disease Models, Animal; D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D007429:Intraocular Pressure; D053685:Laser Therapy; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008297:Male; D009900:Optic Nerve / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D014129:Trabecular Meshwork / Q000601:surgery; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D018698:Glutamic Acid