title: Relationship among visual field, blood flow, and neural structure measurements in glaucoma.
abstract: OBJECTIVE
  To determine the relationship among visual field, neural structural, and blood flow measurements in glaucoma.
  
  
  METHODS
  Case-control study. Forty-seven eyes of 42 patients with perimetric glaucoma were age-matched with 27 normal eyes of 27 patients. All patients underwent Doppler Fourier-domain optical coherence tomography to measure retinal blood flow and standard glaucoma evaluation with visual field testing and quantitative structural imaging. Linear regression analysis was performed to analyze the relationship among visual field, blood flow, and structure, after all variables were converted to logarithmic decibel scale.
  
  
  RESULTS
  Retinal blood flow was reduced in glaucoma eyes compared to normal eyes (P < 0.001). Visual field loss was correlated with both reduced retinal blood flow and structural loss of rim area and retinal nerve fiber layer (RNFL). There was no correlation or paradoxical correlation between blood flow and structure. Multivariate regression analysis revealed that reduced blood flow and structural loss are independent predictors of visual field loss. Each dB decrease in blood flow was associated with at least 1.62 dB loss in mean deviation (P ≤ 0.001), whereas each dB decrease in rim area and RNFL was associated with 1.15 dB and 2.56 dB loss in mean deviation, respectively (P ≤ 0.03).
  
  
  CONCLUSIONS
  There is a close link between reduced retinal blood flow and visual field loss in glaucoma that is largely independent of structural loss. Further studies are needed to elucidate the causes of the vascular dysfunction and potential avenues for therapeutic intervention. Blood flow measurement may be useful as an independent assessment of glaucoma severity.
authors.affiliation: Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Hwang
authors.forename: Ranjith
authors.initials: R
authors.lastname: Konduru
authors.forename: Xinbo
authors.initials: X
authors.lastname: Zhang
authors.forename: Ou
authors.initials: O
authors.lastname: Tan
authors.forename: Brian A
authors.initials: BA
authors.lastname: Francis
authors.forename: Rohit
authors.initials: R
authors.lastname: Varma
authors.forename: Mitra
authors.initials: M
authors.lastname: Sehi
authors.forename: David S
authors.initials: DS
authors.lastname: Greenfield
authors.forename: Srinivas R
authors.initials: SR
authors.lastname: Sadda
authors.forename: David
authors.initials: D
authors.lastname: Huang
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D016014:Linear Models; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D012039:Regional Blood Flow / Q000502:physiology; D012171:Retinal Vessels / Q000473:pathology / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*