title: Dimensions of the foveal avascular zone using the Heidelberg retinal angiogram-2 in normal eyes.
abstract: OBJECTIVE
  The purpose was to study the dimensions of the foveal avascular zone (FAZ) using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany).
  
  
  METHODS
  An observational study of the FAZ area and circumference was done with fundus fluorescein angiography (FFA) using HRA-2 in 31 normal individuals. The FAZ was studied using both contrast-adjusted and nonadjusted methods. Contrast adjustment was done to obtain better visualization of the finer capillaries around the fovea enabling more precise measurements of the FAZ in normal eyes.
  
  
  RESULTS
  The mean area of the FAZ calculated by the contrast-adjusted method was 0.2753 mm 2 (±0.074) and the mean circumference was 2.22 mm (±0.048). By the conventional method, the area and circumference of the FAZ were 0.6241 mm 2 (±0.177) and 3.23 mm (±0.454), respectively.
  
  
  CONCLUSIONS
  The measurements of area and circumference of FAZ using contrast-adjusted methods were significantly smaller than the conventional method.
authors.affiliation: Department of Ophthalmology, Christian Medical College, Vellore - 632002, Tamil Nadu, India. deeparebeccajohn@gmail.com
authors.forename: Deepa
authors.initials: D
authors.lastname: John
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuriakose
authors.forename: Suresh
authors.initials: S
authors.lastname: Devasahayam
authors.forename: Andrew
authors.initials: A
authors.lastname: Braganza
mesh_terms: D000328:Adult; D002196:Capillaries / Q000000981:diagnostic imaging; D005260:Female; D005451:Fluorescein Angiography; D005584:Fovea Centralis / Q000033:anatomy & histology* / Q000098:blood supply; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D011859:Radiography; D012016:Reference Values; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D055815:Young Adult