title: Measuring anterior chamber depth with Orbscan Topography System.
abstract: OBJECTIVE
  To assess the reliability of the Orbscan Topography System in measuring anterior chamber depth (ACD).
  
  
  METHODS
  Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany.
  
  
  METHODS
  The Orbscan Topography System is a 3-D, scanning slit beam system for analyzing corneal surfaces as well as structures of the anterior segment, e.g., iris, lens. Reflected surface data points are measured in the x, y, and z axes, creating color-coded true surface topography maps. We measured ACD prior to cataract surgery in 56 eyes of 37 patients (mean age 70.4 years + 13.2 [SD]) using the Orbscan system and, as a control, the Grieshaber Biometric System (ultrasound) and the Jäger ACD slitlamp measurement system.
  
  
  RESULTS
  Mean ACD values measured with the Orbscan system were 3.23 +/- 0.55 mm; ultrasound measurements were 3.27 +/- 0.54 mm and Jäger measurements, 3.10 +/- 0.55 mm. The average difference between Orbscan and ultrasound values was 0.04 +/- 0.15 mm. The correlation coefficient between Orbscan and ultrasound was 0.96 (P < .00001) and between Orbscan and Jäger, 0.899 (P < .0001).
  
  
  CONCLUSIONS
  The ACD measurements by the Orbscan system were equivalent to common reference measurements.
authors.affiliation: Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Germany.
authors.forename: G U
authors.initials: GU
authors.lastname: Auffarth
authors.forename: M R
authors.initials: MR
authors.lastname: Tetz
authors.forename: Y
authors.initials: Y
authors.lastname: Biazid
authors.forename: H E
authors.initials: HE
authors.lastname: Völcker
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D019781:Corneal Topography / Q000295:instrumentation*; D006801:Humans; D009885:Ophthalmology / Q000295:instrumentation; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000295:instrumentation