title: Optical Coherence Tomography Angiography Evaluation of the Parafoveal Vasculature and Its Relationship With Ocular Factors.
abstract: To determine the size and characteristics of the superficial and deep foveal avascular zone (FAZ) in healthy adults by using optical coherence tomography angiography (OCT-A), and to ascertain the effects of demographic and ocular parameters on the FAZ size.
  
  
  
  In a prospective cohort study of 117 healthy volunteers, foveal-centered 3 × 3-mm OCT-A scans were manually graded by certified graders to determine the size of the superficial and deep FAZ. Multiple linear regression analyses were performed to evaluate the impact of demographics and ocular factors, including central retinal thickness (CRT), choroidal thickness, axial length (AL), and spherical equivalent (SE) on superficial and deep FAZ areas.
  
  
  
  The mean age of the participants was 22.5 years, with mean AL of 25.4 mm and mean SE of -4.3 diopters. The mean CRT was 262.8 μm (range, 220-316 μm). The mean superficial FAZ area was 0.24 mm2, while the deep FAZ area was 0.38 mm2 (P < 0.001). Females had a larger superficial (P < 0.001) and deep FAZ (P < 0.001). On univariate linear regression, both superficial and deep FAZ areas had significant correlations with CRT, sex, AL, and SE, but not with age. By multiple linear regression analysis, in normal eyes, superficial FAZ area varied significantly with CRT and sex. Among eyes with high myopia, both superficial and deep FAZ varied significantly with CRT, sex, and choroidal thickness.
  
  
  
  The superficial and deep FAZ areas varied significantly among healthy eyes. Factors such as CRT, sex, SE, AL, and choroidal thickness influence the size of the FAZ.
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore 2Fundus Image Reading Center, National Healthcare Group Eye Institute, Singapore.
authors.forename: Colin S
authors.initials: CS
authors.lastname: Tan
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore.
authors.forename: Louis W
authors.initials: LW
authors.lastname: Lim
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore.
authors.forename: Vernon S
authors.initials: VS
authors.lastname: Chow
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore.
authors.forename: Isaac W
authors.initials: IW
authors.lastname: Chay
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore.
authors.forename: Shoun
authors.initials: S
authors.lastname: Tan
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore.
authors.forename: Kai Xiong
authors.initials: KX
authors.lastname: Cheong
authors.affiliation: National Healthcare Group Eye Institute Tan Tock Seng Hospital, Singapore.
authors.forename: Gabriel T
authors.initials: GT
authors.lastname: Tan
authors.affiliation: Doheny Eye Institute, University of California Los Angeles, Los Angeles, United States.
authors.forename: SriniVas R
authors.initials: SR
authors.lastname: Sadda
mesh_terms: D000328:Adult; D002829:Choroid / Q000000981:diagnostic imaging; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D005500:Follow-Up Studies; D005584:Fovea Centralis / Q000098:blood supply*; D005654:Fundus Oculi; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult