Intraobserver and interobserver repeatability of ocular biometric measurements obtained by means of B-mode ultrasonography in dogs

Abstract

Objective - To assess intra- and interobserver repeatability of ocular biometric measurements obtained by means of high-resolution B-mode ultrasonography in dogs. Animals - 6 Beagles without ocular abnormalities. Procedures - B-mode ultrasonography was performed bilaterally with a 10.5-MHz broadband compact linear array transducer. All measurements were made on 2 different occasions by 2 observers. The Bland-Altman method was used to assess agreement between measurements obtained by the 2 observers and between the 2 sets of measurements obtained by each observer. Results - Intra- and interobserver repeatability was highest for larger measurements, such as depth of the eye and depth of the anterior chamber. When repeatability was examined, bias was significantly different from 0 for only a few measurements, but the percentage difference between observations was as high as 180% for some measurements. Conclusions and Clinical Relevance - Results suggest that most measurements of intraocular distances and structures obtained by means of high-resolution B-mode ultrasonography have acceptable intra- and interobserver repeatability. However, the percentage difference between observations can be high for smaller measurements.