Evaluation of the angle of the anterior chamber using ultrasound biomicroscopy, gonioscopy and a Van Herick examination

Abstract

Abstract Objective To compare the measurement of the angle of the anterior chamber using ultrasound biomicroscopy (UBM), gonioscopy and the Van Herick examination. Methods An observational comparative study was carried out between 3 different methods for the estimation of the iridocorneal angle. A total of 30 subjects with open and closed angles were evaluated using UBM, gonioscopy and Van Herick. In the UBM and gonioscopy assessment all the quadrants were included in the analysis, and in the Van Herick examination the nasal and temporal quadrant were also analyzed. All the examinations included the assessment of both eyes under photo-optical and scotopic illumination conditions. These findings were compared with the kappa concordance test. Results There was no statistically significant difference between the 3 methods in the evaluation of the state of the iridocorneal angle. The consistency between UBM and gonioscopy was better (kappa 0.93) in relation to the estimation of the angle with Van Herick (kappa 0.83). Conclusions The UBM, gonioscopy and Van Herick examinations have comparable results, although gonioscopy in the first instance would be indicated as a routine test for identification of angular closure.