title: Subfoveal choroidal blood flow and central retinal function in retinitis pigmentosa.
abstract: OBJECTIVE
  To determine whether subfoveal choroidal blood flow is altered in retinitis pigmentosa (RP) and whether this alteration is associated with central cone-mediated dysfunction.
  
  
  METHODS
  In 31 RP patients (age range, 15-72 years) with preserved visual acuity (range: 20/30-20/20), subfoveal choroidal blood flow was measured by real-time, confocal laser Doppler flowmetry, and focal macular (18°) electroretinograms (FERGs) were elicited by 41 Hz flickering stimuli. Twenty normal subjects served as controls. The following average blood flow parameters were determined based on three 60-second recordings: volume (ChBVol), velocity (ChBVel), and flow (ChBF), the last being proportional to blood flow if the hematocrit remains constant. The amplitude and phase of the FERG first harmonic component were measured.
  
  
  RESULTS
  On average, ChBF and ChBVel were reduced by 26% (P ≤ 0.02) in RP patients compared to controls, whereas ChBVol was similar in the two groups. FERG amplitudes were reduced by 60% (P < 0.01) in patients compared with controls. FERG phases of patients tended to be delayed (P < 0.08) compared with their values in the controls. In patients, FERG phase delays were correlated (r = 0.50, P < 0.01) with ChBF and ChBVel values. FERG amplitudes were correlated (r = 0.49, P < 0.01) with ChBVol values.
  
  
  CONCLUSIONS
  These data indicate significant alterations of subfoveal choroidal hemodynamic in RP and suggest a link between the alteration of ChBF and the RP-associated central cone-mediated dysfunction as assessed by the FERG.
authors.affiliation: Department of Ophthalmology and Otolaryngology, Catholic University, Rome, Italy. bfalsini@rm.unicatt.it
authors.forename: Benedetto
authors.initials: B
authors.lastname: Falsini
authors.forename: Gian Mario
authors.initials: GM
authors.lastname: Anselmi
authors.forename: Dario
authors.initials: D
authors.lastname: Marangoni
authors.forename: Fabiana
authors.initials: F
authors.lastname: D'Esposito
authors.forename: Antonello
authors.initials: A
authors.lastname: Fadda
authors.forename: Antonio
authors.initials: A
authors.lastname: Di Renzo
authors.forename: Emilio C
authors.initials: EC
authors.lastname: Campos
authors.forename: Charles E
authors.initials: CE
authors.lastname: Riva
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002648:Child; D002829:Choroid / Q000098:blood supply*; D004596:Electroretinography; D005260:Female; D005451:Fluorescein Angiography; D005584:Fovea Centralis; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D012160:Retina / Q000502:physiology*; D012174:Retinitis Pigmentosa / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D055815:Young Adult