Measurement of ultrasound biomicroscopy images: intraobserver and interobserver reliability.

Abstract

PURPOSE: To evaluate intraobserver and interobserver reproducibility of measurement of images obtained during ultrasound biomicroscopy. METHODS: Four anterior segment images of four normal patients were obtained by a single examiner. The measurements of three independent observers were compared to assess interobserver reproducibility in quantifying the images. Thirteen different anterior segment parameters were measured by each observer on each image. Intraobserver and interobserver reproducibility of measurement were assessed by calculating the coefficient of variation for each individual observer and by using the F test to detect a difference among observers. RESULTS: Intraobserver reproducibility was high. Interobserver reproducibility for the measured parameters varied considerably and was affected by subjective interpretation of visualized anatomic landmarks. CONCLUSIONS: The optimal parameters for quantitative ultrasound biomicroscopy require refinement. Measurements of alterable parameters are best measured presently by a single observer. Ultrasound biomicroscopy has the potential to elucidate anatomic relationships underlying much anterior segment disease, but caution in interpreting quantitative differences is warranted.