title: Between-grader repeatability of tear meniscus measurements using Fourier-domain OCT in patients with dry eye.
abstract: OBJECTIVE
  To examine the between-grader repeatability of height, depth, and cross-sectional area measurements of the lower tear meniscus, using a Fourier-domain optical coherence tomography (OCT) system.
  
  
  METHODS
  A total of 16 patients with dry eye had the lower tear meniscus of the right eye imaged twice in rapid succession. The tear meniscus height, depth, and cross-sectional area were measured by two masked graders using computer calipers. The between-grader variability, calculated using the pooled coefficient of variation (CV%), assessed the repeatability of the measurements.
  
  
  RESULTS
  The between-grader CV% was 12.1%, 15.7%, and 19.5% for height, depth, and area, respectively. The between-image variability was 17.1%, 13.4%, and 35.4% for height, depth, and area, respectively. The overall intraclass correlation was 99%. There was no systematic bias between the two graders.
  
  
  CONCLUSIONS
  Fourier-domain OCT demonstrates good between-grader and between-image repeatability in measuring the height, depth, and cross-sectional area of the tear meniscus in patients with dry eye. Measurement variability was primarily due to the difference between images rather than graders.
authors: Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
authors: Ethan H
authors: EH
authors: Tittler
authors: Matthew C
authors: MC
authors: Bujak
authors: Pho
authors: P
authors: Nguyen
authors: Xinbo
authors: X
authors: Zhang
authors: Yan
authors: Y
authors: Li
authors: Samuel C
authors: SC
authors: Yiu
authors: David
authors: D
authors: Huang
mesh_terms: D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000503:physiopathology*; D005583:Fourier Analysis; D006801:Humans; D015588:Observer Variation; D015203:Reproducibility of Results; D013666:Tears; D041623:Tomography, Optical Coherence / Q000379:methods*