Repeatability and Reliability of Quantified Ultrasound Biomicroscopy Image Analysis of the Ciliary Body at the Pars Plicata

Joy Li, Jennifer Drechsler, Anna Lin, Matthew Widlus, Azam Qureshi, Gianna Stoleru, Osamah Saeedi, M. Roni Levin, Mona Kaleem, Mohamad Jaafar, William P. Madigan, Janet Leath Alexander

Research output: Contribution to journalArticlepeer-review


Most of the ciliary body and ciliary processes of the eye cannot be directly visualized in vivo because of the posterior location of the pars plicata to the posterior chamber and iris. However, ciliary anatomy can be effectively imaged using ultrasound biomicroscopy (UBM) by placing the probe close to the limbus, perpendicular to this structure. Previous studies measuring ciliary body parameters in meridian UBM images found that these parameters were measured with poor reliability and repeatability. This study evaluates the intra-observer reliability and inter-observer agreement of a standardized protocol for measuring six ciliary parameters in transverse or quadrant UBM images that capture an entire row of ciliary processes. All six ciliary parameters have high intra-observer reliability, with ciliary body thickness, ciliary process length and ciliary process density measurements being the most consistent for each observer. The coefficient of variation for each observer ranged from 1.4%–15%. Inter-observer agreement was also high for all six parameters, with an intra-class correlation coefficient >0.8. Utilizing transverse UBM images of the pars plicata allows for consistent quantitative analysis in control subjects.

Original languageEnglish (US)
Pages (from-to)1949-1956
Number of pages8
JournalUltrasound in Medicine and Biology
Issue number7
StatePublished - Jul 2021
Externally publishedYes


  • Ciliary body
  • Ciliary processes
  • Pars plana
  • Pars plicata
  • Posterior chamber
  • Reliability
  • Repeatability
  • Ultrasound biomicroscopy

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Biophysics
  • Acoustics and Ultrasonics


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