Normative Values for Corneal Densitometry Analysis by Scheimpflug Optical Assessment

PURPOSE. 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.