title: Ocular blood flow velocity in primary open angle glaucoma--a tropical African population study.
abstract: OBJECTIVE
  To assess blood flow velocity in newly diagnosed indigenous black-skinned Africans with primary open angle glaucoma (POAG).
  
  
  METHODS
  Prospective case-control study at Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria on 50 newly diagnosed POAG patients (POAG group) and 50 control patients (control group). Ocular Doppler Color Imaging was performed on subjects in the supine position using 9 MHz linear array transducer of a Fukuda Denshi Ultrasound. The Peak Systolic Velocity (PSV) and End Diastolic Velocity (EDV) values were obtained by finding the average of two readings each for the ophthalmic artery (OA) and central retinal artery (CRA). Resistive Index (RI) was calculated as (PSV - EDV)/PSV. Data were analyzed and statistical significance was defined at P < 0.05.
  
  
  RESULTS
  The mean intraocular pressure (IOP) for the POAG group and control group was 28.1 ± 7.4 mmHg and 16.6 ± 2.0 mmHg, respectively (P < 0.001). The mean PSV for OA was 31.35 cm/s in POAG group and 37.61 cm/s for the control group (P < 0.001). The EDV for both OA and CRA were significantly lower in glaucoma patients as compared with the corresponding values in the control group (P < 0.001, both comparisons). The mean RI in the OA was 0.71 ± 0.05 and 0.63 ± 0.03 for the POAG and control group groups, respectively (P < 0.001). The increase in IOP in the POAG group was statistically significantly negatively correlated with PSV and EDV and positively correlated with RI for both OA and CRA.
  
  
  CONCLUSIONS
  The outcomes of this study indicate that ocular blood flow alterations including reductions in PSV and EDV and increase in RI of the OA and CRA are present in black-skinned Africans with POAG.
authors.affiliation: Department of Radiology, College of Health Sciences, Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria.
authors.forename: Odunlami Olufemi
authors.initials: OO
authors.lastname: Adeyinka
authors.forename: Ayoola
authors.initials: A
authors.lastname: Olugbenga
authors.forename: Onakpoya Oluwatoyin
authors.initials: OO
authors.lastname: Helen
authors.forename: Adetiloye Victor
authors.initials: AV
authors.lastname: Adebayo
authors.forename: Arogundade
authors.initials: A
authors.lastname: Rasheed
mesh_terms: D000328:Adult; D000368:Aged; D044383:Black People / Q000208:ethnology; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D019842:Ciliary Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000208:ethnology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009549:Nigeria; D011446:Prospective Studies; D012161:Retinal Artery / Q000000981:diagnostic imaging / Q000502:physiology; D014065:Tonometry, Ocular; D018615:Ultrasonography, Doppler, Color
keywords: Black-skinned Africans; Case-Control; Case-Control Group; Glaucoma; Intraocular Pressure; Ocular Doppler; Resistive Index