Inter-observer agreement in evaluating the anterior chamber angle by ultrasound biomicroscopy

Purpose. To determine the agreement between observers in estimating the configuration of the human anterior chamber angle (ACA) using ultrasound biomicroscopy (UBM). Methods. Two masked clinicians used UBM images to estimate, in 41 eyes, the configuration of the ACA, especially (1) the position of contact between the peripheral iris and the inside of the eye wall, (2) the angularity of the approach to the ACA, and (3) the curvature of the peripheral iris. Agreement between observers was evaluated by the kappa statistic. Results. Inter-observer agreement in assessing the iris insertion (kappa = 0.79), angular width (Kappa = 0.95), and the peripheral iris curvature (kappa = 0.84) was high. Conclusions. The agreement between observers in evaluating the anterior chamber angle configuration by UBM was excellent.