title: Determination of ascorbic acid in human vitreous humor by high-performance liquid chromatography with UV detection.
abstract: OBJECTIVE
  Ascorbic acid (AA) accumulates in vitreous at a concentration several times higher than in plasma. It has been suggested that AA may serve as an antioxidant that protects ocular tissues from free radical attack. There are many reports about the concentration of AA in ocular tissues. However, AA in adult human vitreous humor has not been determined. We measured concentrations of AA from pathologic human vitreous samples and compared the results.
  
  
  METHODS
  AA was measured by high-performance liquid chromatography (HPLC) with UV detection. Human vitreous humor was collected from patients undergoing pars plana vitrectomy.
  
  
  RESULTS
  AA was quantified in vitreous humor of proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), macular hole (MH), idiopathic premacular fibrosis (PMF), and Terson syndrome (Terson). The concentrations of AA were 120.9 +/- 36.3 micrograms/ml (mean +/- SD), 129.8 +/- 36.6, 311.5 +/- 126.7, 446.9 +/- 154.2 and 406.0 +/- 22.0, respectively. There was no significant difference between the PDR and the PVR groups (unpaired t-test). Patients with PDR and PVR showed significantly lower concentrations of AA than those with MH, PMF, and Terson (p < 0.01).
  
  
  CONCLUSIONS
  These findings suggest that increased oxidative stress may be produced in the ocular tissues of eyes with PDR and PVR, and AA appears to be consumed (oxidized) in performing its protective role.
authors.affiliation: Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takano
authors.forename: S
authors.initials: S
authors.lastname: Ishiwata
authors.forename: M
authors.initials: M
authors.lastname: Nakazawa
authors.forename: M
authors.initials: M
authors.lastname: Mizugaki
authors.forename: M
authors.initials: M
authors.lastname: Tamai
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006801:Humans; D014466:Ultraviolet Rays; D014822:Vitreous Body / Q000378:metabolism*
chemical_list: D001205:Ascorbic Acid