Agreement between Orbscan II, VuMAX UBM and Artemis-2 very-high frequency ultrasound scanner for measurement of anterior chamber depth

Abstract

BackgroundThe aim was to compare the anterior chamber depth (ACD) measurements taken with Orbscan II, ultrasound biomicroscopy (UBM) and the Artemis-2 VHF (very-high-frequency) ultrasound scanner in normal subjects.MethodsIn this prospective study, one eye from each of 60 normal subjects was randomly selected. Three subjects dropped out of the study because they were apprehensive about the UBM examination; their data were excluded entirely. Measurements of ACD were taken with the Orbscan II, UBM and Artemis-2 VHFUS. Results were obtained for coefficient of variance (CV) and intra-class correlation coefficient (ICC), and statistical analysis was by repeated-measures analysis of variance (ANOVA) for intra-observer repeatability. ANOVA and Bland–Altman analyses were used to determine limits of agreement (LOA) between the three instruments.ResultsThe average ACD (± standard deviation) was 3.13 ± 0.34 mm, 2.96 ± 0.27 mm and 2.87 ± 0.31 mm for the Orbscan II, UBM and Artemis-2 VHFUS, respectively. The repeatability scores were 0.015 ± 0.014%, 0.08 ± 0.09% and 0.07 ± 0.06% for the Orbscan II, UBM and Artemis-2 VHFUS, respectively. The ICC for repeatability of Orbscan II, UBM and Artemis-2 VHFUS measurements was high and equal to 0.99%. The intra-observer repeatability scores of the ACD measurement p-values using Orbscan II, UBM and Artemis-2 VHFUS were 0.12, 0.70 and 0.10, respectively. The mean difference and standard deviations for ACD measurements using Orbscan II vs UBM, Orbscan II vs Artemis-2 VHFUS and UBM vs Artemis-2 VHFUS were 0.17 ± 0.31 mm, 0.27 ± 0.34 mm and 0.10 ± 0.18 mm, respectively. LOAs were 0.78 to -0.44 mm, 0.93 to -0.39 mm and 0.45 to -0.26 mm. ANOVA revealed a statistically significant difference between the Orbscan II, UBM and Artemis-2 VHFUS (p < 0.0001).ConclusionsMeasurements by the three instruments show high repeatability. UBM and the Artemis-2 VHFUS can be used interchangeably, but the Orbscan II cannot be used interchangeably with UBM or the Artemis-2 VHFUS.

Measurement of Angle Kappa Using Ultrasound Biomicroscopy and Corneal Topography

“…There have been numerous studies assessing the agreement among devices that measure anterior chamber depth. Reddy et al [ 14 ] and Al Farhan [ 15 ] reported that contact-based devices resulted in lower measurements for anterior chamber depth compared with Orbscan II and IOLMaster. Meanwhile, Vetrugno et al [ 16 ] reported that optical measurement of the anterior chamber depth with Orbscan II yielded a small underestimation.…”

A new algorithm and problems in automatic anterior eye chamber volume determining

“…Several imaging techniques have been used for anterior chamber depth (ACD) assessment: Scheimflug camera [1,2], scanning-slit topography [3,4], ultrasonic immersion instruments [5,6] and optical coherence tomography [7,8].…”

Anterior chamber depth measurement using ultrasound to assess elevated intraocular pressure

“…Among others specialized US, biomicroscopy was used to measure the ACD to analyze the intraocular lens position postoperatively. Its measurements were compared with that of the Artemis-2 very high-frequency US scanner [2][3][4][5][6]. The study concluded that the 2 devices can be used interchangeably for measurement of ACD.…”