Anterior chamber volume measurements with Visante optical coherence tomography and Pentacam: repeatability and level of agreement

Background:  The purpose of this study is to examine the repeatability of Pentacam-derived anterior chamber volume measurements, and assess the level of agreement of anterior chamber volume measurements obtained with the Visante and the Pentacam imaging devices.
Methods:  Anterior chamber volume was calculated with the Pentacam device and the Visante using the Wang formula. Results were analysed by means of the Wilcoxon signed rank test, Bland-Altman analysis, Cronbach's alpha test and intraclass correlation coefficient. P -values <0.01 were considered statistically significant.
Results:  One randomly selected eye from each of 20 persons was analysed. Spherical equivalent ranged between −2.50 and +1.50 D, and their age ranged from 25 to 79 years (mean ± SD: 54.4 ± 19.2 years). Mean anterior chamber volume measured with Pentacam was 171.1 ± 39.6 µL (minimum: 103.0 µL, maximum: 236.0 µL), and mean anterior chamber volume measured by Visante was 171.4 ± 42.4 µL (minimum: 96.4 µL, maximum: 245.5 µL). There was no statistically significant difference between Pentacam and Visante measurements of the anterior chamber volume ( P  = 0.691, Wilcoxon signed rank test). Cronbach's alpha and intraclass correlation coefficient for Pentacam were 0.998 and 0.991, respectively.
Conclusions:  Anterior chamber volume measurements obtained with the Visante using the Wang formula were in good agreement with the corresponding ones obtained with Pentacam. This recently described method is easy to perform and might contribute to both clinical and research settings.