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Abstract #5307 Published in IGR 1-2
Ultrasound biomicroscopy. III. Accuracy and agreement of measurements
Urbak SFActa Ophthalmologica Scandinavica 1999; 77: 293-297
PURPOSE: To estimate the accuracy of measurements by the 50 MHz Humphrey Ultrasound Biomicroscopy and evaluate the agreement of measurements by ultrasound biomicroscopy and optical pachometry. METHODS: The accuracy was estimated by comparing measurements by ultrasound biomicroscopy with more exact mechanical methods. Forty-seven PMMA intraocular lenses and 52 distances between horizontally separated sutures were measured. The agreement between ultrasound biomicroscopy and optical pachometry was evaluated by comparing measurements of central cornea thickness and anterior chamber depth of 46 eyes. RESULTS: The axial measurements by ultrasound biomicroscopy were on average 10 ?m higher than the reference method (SEM 3 ?m). The lateral measurements were not systematically different from the reference method (SEM 5 ?m). The mean central corneal thickness was considerably higher with optical pachometry, 557 ? 5 ?m (SEM), than with ultrasound biomicroscopy, 533 ? 5 ?m. It was similar for anterior chamber depth where the mean measurements were 2955 ? 66 ?m and 2897 ? 63 ?m, respectively. CONCLUSIONS: The axial and lateral accuracy of ultrasound biomicroscopic measurements was good. The agreement between measurements obtained by ultrasound biomicroscopy and optic pachometry was poor in this investigation. Several circumstances could account for this.
S.F. Urbak, Department of Ophthalmology, Aalborg Sygehus, Aalborg; Denmark
Classification:
6.12 Ultrasonography and ultrasound biomicroscopy (Part of: 6 Clinical examination methods)