title: Ocular pulse amplitude and retrobulbar blood flow change in dipper and non-dipper individuals.
abstract: OBJECTIVE
  To evaluate ocular pulse amplitude (OPA), IOP values, and hemodynamic changes in the ophthalmic artery, central retinal artery, and short posterior ciliary artery in dipper and non-dipper patients.
  
  
  METHODS
  A total of 59 right eye measurements of healthy subjects with normotensive were included to the study. Ambulatory blood pressure (BP) monitoring measurement (ABPM), Doppler imaging, and OPA measurements were performed in the same day. The patients in which systolic BP decreased during the nocturnal time by 10% of the diurnal BP or more were called dippers. A patient whose nocturnal systolic BP fell by <10% or even rose was defined as non-dipper. Color Doppler imaging was used for blood flow velocity assessment of ophthalmic, central retinal, and posterior ciliary arteries. For each artery, peak systolic and end-diastolic velocities (PSV and EDV, respectively), resistive index (RI), and pulsalite index (PI) were automatically calculated by the machine. Mean IOP and OPA values were calculated after three consecutive measurements.
  
  
  RESULTS
  The mean OPA in non-dipper patients was significantly lower compared with that of dipper patients (P=0.011). There was no significant difference in IOP levels between groups. There was no significant difference in the PSV, EDV, RI, and PI in the ophthalmic, posterior ciliary, and central retinal arteries between the groups.
  
  
  CONCLUSIONS
  Our study demonstrated that OPA level in non-dippers is lower than dippers. This may give additional information about the effect of BP changes on OPA values.
authors.affiliation: Yuzuncu Yil University, Medical School, Department of Ophthalmology, Van, Turkey. drrkaradag@yahoo.com
authors.forename: R
authors.initials: R
authors.lastname: Karadag
authors.forename: U C
authors.initials: UC
authors.lastname: Keskin
authors.forename: A
authors.initials: A
authors.lastname: Koktener
authors.forename: Y
authors.initials: Y
authors.lastname: Selcoki
authors.forename: I F
authors.initials: IF
authors.lastname: Hepsen
authors.forename: M
authors.initials: M
authors.lastname: Kanbay
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D019842:Ciliary Arteries / Q000000981:diagnostic imaging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D012161:Retinal Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D014065:Tonometry, Ocular; D018615:Ultrasonography, Doppler, Color