title: Normative values for corneal densitometry analysis by Scheimpflug optical assessment.
abstract: OBJECTIVE
  To describe the normative data for corneal Scheimpflug densitometry based on a cohort of normal participants.
  
  
  METHODS
  A total of 445 healthy participants were recruited for assessment (794 eyes). Left and right eyes were considered separately. All participants were assessed using the corneal densitometry analysis add-on to the standard software of the Oculus Pentacam. Densitometry measurements were obtained and expressed in standardized grayscale units (GSU).
  
  
  RESULTS
  All participants were Caucasian; 42% were male and 58% were female. The mean age was 48.0 ± 15.3 years (range, 20.2-84.2 years). Mean corneal densitometry over the 12-mm-diameter area was 19.74 ± 3.89 GSU. When divided by radial zone, densitometry values were lowest in the central zone (16.76 ± 1.87 GSU) and highest in the periphery (27.36 ± 7.47 GSU). There was no difference between central zone and the surrounding 2- to 6-mm annulus (P > 0.05), though the 6- to 10-mm and the 10- to 12-mm zones displayed higher densitometry values (P < 0.001). When divided by depth, the anterior layer displayed the highest densitometry reading of 25.81 ± 5.14 GSU, which was significantly higher than that of both the central (P < 0.001) and the posterior layers (P < 0.001). Changes in corneal densitometry were correlated with age, though not within the central 6-mm-diameter ring. No sex difference was seen within the cohort.
  
  
  CONCLUSIONS
  This add-on to the standard imaging software allows rapid and objective assessment of the corneal densitometry. We provide normative data that may be used as a reference facilitating research and complementing clinical examination.
authors: Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium.
authors: Sorcha
authors: S
authors: Ní Dhubhghaill
authors: Jos J
authors: JJ
authors: Rozema
authors: Sien
authors: S
authors: Jongenelen
authors: Irene
authors: I
authors: Ruiz Hidalgo
authors: Nadia
authors: N
authors: Zakaria
authors: Marie-José
authors: MJ
authors: Tassignon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea / Q000033:anatomy & histology*; D019781:Corneal Topography / Q000379:methods; D003720:Densitometry / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Pentacam; Scheimpflug; cornea; densitometry