title: Racial differences in ocular oxidative metabolism: implications for ocular disease.
abstract: OBJECTIVE
  To compare the Po(2) distribution in different regions in the eyes of patients undergoing intraocular surgery.
  
  
  METHODS
  Before initiation of intraocular cataract and/or glaucoma surgery, an optical oxygen sensor was introduced into the anterior chamber via a peripheral corneal paracentesis. The tip of the flexible fiberoptic probe was positioned by the surgeon for 3 measurements in all patients: (1) near the central corneal endothelium, (2) in the mid-anterior chamber, and (3) in the anterior chamber angle. In patients scheduled to undergo cataract extraction, Po(2) was also measured (4) at the anterior lens surface and (5) in the posterior chamber just behind the iris. Oxygen measurements at the 5 locations were compared using a 2-tailed unpaired t test and multivariate regression.
  
  
  RESULTS
  The Po(2) value was significantly higher in African American patients at all 5 locations compared with Caucasian patients. Adjusting for age increased the significance of this association. Adjusting for race revealed that age was associated with increased Po(2) beneath the central cornea.
  
  
  CONCLUSIONS
  Racial differences in oxygen levels in the human eye reflect an important difference in oxidative metabolism in the cornea and lens and may reflect differences in systemic physiologic function. Increased oxygen or oxygen metabolites may increase oxidative stress, cell damage, intraocular pressure, and the risk of developing glaucoma. Oxygen use by the cornea decreases with age.
authors: Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO 63110, USA. siegfried@vision.wustl.edu
authors: Carla J
authors: CJ
authors: Siegfried
authors: Ying-Bo
authors: YB
authors: Shui
authors: Nancy M
authors: NM
authors: Holekamp
authors: Fang
authors: F
authors: Bai
authors: David C
authors: DC
authors: Beebe
mesh_terms: D001741:Black or African American; D000368:Aged; D000869:Anterior Eye Segment / Q000378:metabolism*; D002386:Cataract / Q000208:ethnology; D002387:Cataract Extraction; D005260:Female; D005902:Glaucoma, Open-Angle / Q000208:ethnology / Q000601:surgery; D006801:Humans; D017736:Ion-Selective Electrodes; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D010313:Partial Pressure; D044465:White People
chemical_list: D010100:Oxygen