title: High-frequency ultrasound measurements of the normal ciliary body and iris.
abstract: OBJECTIVE
  To determine the normal ultrasonographic thickness of the iris and ciliary body.
  
  
  METHODS
  This prospective 35-MHz ultrasonographic study included 80 normal eyes of 40 healthy volunteers. The images were obtained at the 12-, 3-, 6-, and 9-o'clock radial meridians, measured at three locations along the radial length of the iris and at the thickest section of the ciliary body. Mixed model was used to estimate eye site-adjusted means and standard errors and to test the statistical difference of adjusted results. Parameters included mean thickness, standard deviation, and range.
  
  
  RESULTS
  Mean thicknesses at the iris root, midway along the radial length of the iris, and at the juxtapupillary margin were 0.4 ± 0.1, 0.5 ± 0.1, and 0.6 ± 0.1 mm, respectively. Those of the ciliary body, ciliary processes, and ciliary body + ciliary processes were 0.7 ± 0.1, 0.6 ± 0.1, and 1.3 ± 0.2 mm, respectively.
  
  
  CONCLUSIONS
  This study provides standard, normative thickness data for the iris and ciliary body in healthy adults using ultrasonographic imaging.
authors.affiliation: The New York Eye and Ear Infirmary, New York, USA.
authors.forename: Julian P S
authors.initials: JP
authors.lastname: Garcia
authors.forename: Leigh
authors.initials: L
authors.lastname: Spielberg
authors.forename: Paul T
authors.initials: PT
authors.lastname: Finger
mesh_terms: D000328:Adult; D001837:Body Weights and Measures; D002924:Ciliary Body / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007498:Iris / Q000000981:diagnostic imaging*; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D055815:Young Adult