title: Peripapillary retinal blood flow in normal tension glaucoma.
abstract: OBJECTIVE
  To determine if normal tension glaucoma (NTG) patients differ from age matched controls in blood flow to the peripapillary retina, as measured with confocal scanning laser Doppler flowmetry (cSLDF; "Heidelberg retinal flowmetry").
  
  
  METHODS
  12 NTG patients and 12 age matched controls were compared using (a) 10 x 10 pixel boxes (the instrument default sample size), taken from the nasal and temporal peripapillary retina, (b) the average from two of these boxes, and (c) every qualifying pixel within the peripapillary retina.
  
  
  RESULTS
  Patients and controls did not differ in blood flow measured using the default sample from a single 10 x 10 pixel box, placed in either the temporal or nasal peripapillary retina, or expressed as the average from these two boxes. However, in histograms using every pixel from the peripapillary retina, NTG patients displayed significantly higher percentages of minimal flow pixels (defined as less than one arbitrary unit of flow: 30% v 19%, p < 0.01), and significantly lower flow in the 25th, 50th, and 75th percentile flow pixel (each p < 0.05) than did age matched controls.
  
  
  CONCLUSIONS
  NTG is characterised by reduced blood flow in the peripapillary retina, a result suggesting that blood flow deficits accompany, and perhaps may contribute to, disease development in these patients.
authors.affiliation: Department of Ophthalmology, Indiana University School of Medicine, Indianapolis 4602-6195, USA.
authors.forename: H S
authors.initials: HS
authors.lastname: Chung
authors.forename: A
authors.initials: A
authors.lastname: Harris
authors.forename: L
authors.initials: L
authors.lastname: Kagemann
authors.forename: B
authors.initials: B
authors.lastname: Martin
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009900:Optic Nerve / Q000098:blood supply; D012171:Retinal Vessels / Q000503:physiopathology*