title: Measurement of iris color using computerized image analysis.
abstract: OBJECTIVE
  To develop a standardized method for measuring from iris photographs, light and dark segments of areas and densities of iris color.
  
  
  METHODS
  Computerized image analysis was used to measure the iris photographs. The reproducibility of this method was studied in 30 normal eyes with three different colored irides, green-brown, blue-grey brown and yellow-brown. Three photographs were taken of each iris with a slit lamp camera at three different exposures at baseline. The photographs were repeated with exposure providing for the best reproducibility at 6.5 +/- 1.7 months as a first follow-up after baseline and 3.6 +/- 0.8 months following the first follow-up visit. At least one measurement was made for each photograph.
  
  
  RESULTS
  The mean percent coefficient of variation (standard deviation of triplicate measurements/mean x 100) ranged from 1.0 to 4.1% for area and density measurements. Furthermore, the range of mean percent differences between baseline and follow-up visits ranged from 1.2 to 6.3%.
  
  
  CONCLUSIONS
  We have developed a standardized method which appears suitable for measuring changes over time in iris color.
authors.affiliation: Glaucoma Research, Inc., Boston, MA 02116, USA.
authors.forename: T
authors.initials: T
authors.lastname: Takamoto
authors.forename: B
authors.initials: B
authors.lastname: Schwartz
authors.forename: L B
authors.initials: LB
authors.lastname: Cantor
authors.forename: J S
authors.initials: JS
authors.lastname: Hoop
authors.forename: T
authors.initials: T
authors.lastname: Steffens
mesh_terms: D000368:Aged; D005127:Eye Color; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007498:Iris / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D010781:Photography; D010860:Pigments, Biological / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D010860:Pigments, Biological