title: Association of risk factors for choroidal neovascularization in age-related macular degeneration with decreased foveolar choroidal circulation.
abstract: OBJECTIVE
  To investigate the relationship between known risk factors for age-related macular degeneration (AMD) progression and foveolar choroidal circulation in eyes with nonexudative AMD.
  
  
  METHODS
  Cross-sectional study of nonexudative AMD.
  
  
  METHODS
  Laser Doppler flowmetry measurements of relative choroidal blood velocity, choroidal blood volume (ChBVol), and choroidal blood flow (ChBFlow) were obtained in the center of the fovea of 273 study eyes of 204 AMD patients investigated at the Scheie Eye Institute, University of Pennsylvania Medical School. All study eyes had visual acuity of 20/40 or better, good fixation, no other intraocular pathologic features, and no evidence of choroidal neovascularization. RPE hypertrophy was determined from color fundus photographs by trained masked graders at the Scheie Image Reading Center. Correlation analysis and multivariate linear regression analysis with adjustments for significant covariates were carried out.
  
  
  RESULTS
  A significant inverse correlation was observed between age and ChBFlow (r = -0.36; P < .0001), and ChBVol (r = -0.28; P < .0001), but not for choroidal blood velocity. A significant inverse correlation was observed between spherical equivalent and ChBFlow (r = -0.21; P = .006) and ChBVol (r = -0.14; P = .04), but not for choroidal blood velocity. ChBFlow and ChBVol were significantly lower in patients with a history of hypertension (P < or = .003) and in eyes with retinal pigment epithelium hypertrophy (P < or = .04), respectively.
  
  
  CONCLUSIONS
  All the above-described risk factors for AMD development and progression are associated with decreased choroidal circulatory parameters, suggesting that decreases in choroidal circulatory parameters may be involved in the development of AMD.
authors.affiliation: Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania School of Medicine, Philadelphia, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Juan E
authors.initials: JE
authors.lastname: Grunwald
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Metelitsina
authors.forename: Joan C
authors.initials: JC
authors.lastname: DuPont
authors.forename: Gui-Shuang
authors.initials: GS
authors.lastname: Ying
authors.forename: E Revell
authors.initials: ER
authors.lastname: Martin
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Dunaief
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Brucker
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001775:Blood Circulation; D001783:Blood Flow Velocity; D002829:Choroid / Q000098:blood supply*; D020256:Choroidal Neovascularization / Q000209:etiology* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005584:Fovea Centralis; D006801:Humans; D006984:Hypertrophy; D017078:Laser-Doppler Flowmetry; D008268:Macular Degeneration / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D055213:Retinal Pigment Epithelium / Q000473:pathology; D012307:Risk Factors; D014792:Visual Acuity / Q000502:physiology