title: Repeatability, reproducibility, and agreement of central anterior chamber depth measurements in pseudophakic and phakic eyes: optical coherence tomography versus ultrasound biomicroscopy.
abstract: OBJECTIVE
  To evaluate the intraexaminer repeatability, interexaminer reproducibility, and agreement of central anterior chamber depth (ACD) measurements obtained by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in pseudophakic eyes and phakic eyes.
  
  
  METHODS
  Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China.
  
  
  METHODS
  In this prospective study, the central ACD in right pseudophakic eyes and right phakic eyes was measured with the Visante AS-OCT system and the OTI-Scan HF 35-50 UBM system. Intraexaminer repeatability and interexaminer reproducibility were evaluated in a subgroup of eyes from each group. The repeatability and reproducibility of the measurements were evaluated using intraclass correlation coefficients (ICCs) and the Bland-Altman method.
  
  
  RESULTS
  The mean ACD in the 70 pseudophakic eyes was 3.91 mm +/- 0.29 (SD) by AS-OCT and 3.76 +/- 0.33 mm by UBM and in the 70 phakic eyes, 2.97 +/- 0.31 mm and 2.90 +/- 0.32 mm, respectively. The 95% limits of agreement between the 2 methods were -0.32 to 0.62 mm in pseudophakic eyes and -0.11 to 0.25 mm in phakic eyes. The ICC for the repeatability and reproducibility of AS-OCT and UBM measurements was high (range 0.985 to 0.996).
  
  
  CONCLUSIONS
  Both AS-OCT and UBM ACD measurements showed good repeatability and reproducibility. However, the agreement was better in phakic eyes than in pseudophakic eyes. Thus, the measurements should not be used interchangeably in pseudophakic eyes.
authors.affiliation: School of Optometry and Ophthalmology, Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China. bsszhang@hotmail.com
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Wanqing
authors.initials: W
authors.lastname: Jin
authors.forename: Qinmei
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D000886:Anthropometry; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007908:Lens, Crystalline / Q000502:physiology*; D008297:Male; D033401:Microscopy, Acoustic / Q000706:statistics & numerical data*; D008875:Middle Aged; D015588:Observer Variation; D018918:Phacoemulsification; D011446:Prospective Studies; D019591:Pseudophakia / Q000209:etiology / Q000473:pathology*; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000706:statistics & numerical data*