title: Amino-acid levels in subretinal and vitreous fluid of patients with retinal detachment.
abstract: OBJECTIVE
  To compare the concentration of amino acids in subretinal and vitreous fluid of patients with primary rhegmatogenous retinal detachment to that of control vitreous.
  
  
  METHODS
  This prospective, observational study measured amino-acid levels in subretinal fluid of patients undergoing scleral buckle placement (n=20) and vitreous fluid in patients undergoing pars plana vitrectomy (n=5) for primary retinal detachment. Vitreous fluid from patients undergoing vitrectomy for macular hole (n=7) or epiretinal membrane (n=3) served as a control. Subretinal fluid and control vitreous were analysed using high-pressure liquid chromatography. Retinal detachment vitreous was analysed using capillary electrophoresis-laser-induced fluorescence.
  
  
  RESULTS
  Mean levels of glutamate (27.0+/-1.7 microM), aspartate (4.1+/-4.0 microM), and glycine (44.1+/-31.0 microM) in subretinal fluid and glutamate (13.4+/-11.9 microM) in the vitreous were significantly elevated in retinal detachment compared to control vitreous. A significant, positive association was observed between levels of aspartate and glutamate in subretinal fluid (Spearman's correlation coefficient: 0.74, P<0.01). Mean arginine levels did not differ significantly between subretinal fluid and control vitreous. Levels of alanine, tyrosine, valine, isoleucine, leucine, and phenylalanine were significantly lower in subretinal fluid compared to control vitreous (all P<0.01).
  
  
  CONCLUSIONS
  Glutamate levels in subretinal fluid and vitreous of patients with primary retinal detachment is significantly elevated in comparison to control vitreous. This finding lends further support to the hypothesis that elevated glutamate levels may result from ischaemia of the outer retina secondary to retinal detachment.
authors.affiliation: Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Bertram
authors.forename: D V
authors.initials: DV
authors.lastname: Bula
authors.forename: J S
authors.initials: JS
authors.lastname: Pulido
authors.forename: S A
authors.initials: SA
authors.lastname: Shippy
authors.forename: S
authors.initials: S
authors.lastname: Gautam
authors.forename: M-J
authors.initials: MJ
authors.lastname: Lu
authors.forename: R M
authors.initials: RM
authors.lastname: Hatfield
authors.forename: J-H
authors.initials: JH
authors.lastname: Kim
authors.forename: M T
authors.initials: MT
authors.lastname: Quirk
authors.forename: J G
authors.initials: JG
authors.lastname: Arroyo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000032:analysis*; D001224:Aspartic Acid / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005260:Female; D018698:Glutamic Acid / Q000032:analysis; D005998:Glycine / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012160:Retina / Q000737:chemistry*; D012163:Retinal Detachment / Q000378:metabolism* / Q000601:surgery; D012591:Scleral Buckling; D014792:Visual Acuity; D014821:Vitrectomy; D014822:Vitreous Body / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D001224:Aspartic Acid; D018698:Glutamic Acid; D005998:Glycine