Comparison Of Anterior Chamber Depth Measurements Using Galilei, Pentacam, Sirius, Orbscan II, Atlas/Visante and the IOL Master

Abstract

Purpose: : To compare Anterior Chamber Depth (ACD) measurements by six

Methods: : Scanning-Slit Technology (SST), three Scheimpflug Imaging Systems (SIS), optical coherence tomography (OCT), and laser interpherometry (LIP).Methods: This was a prospective single-center study, of 84 eyes of 42 patients were were examined with the Orbscan II (SST) the Pentacam, Galilei, and Sirius systems (all three SIS), the Visante (OCT) and the IOL master (LIP). To assess the intraobserver, interobserver and interdevice reproducibility of the 5 systems, all the eyes were examined 2 times by 2 independent observers and the reliability coefficient was calculated using Cronbach alpha-test.

Results: : The mean ACD were as follows (microns): 2.94 ± 0.31 μm (Orbscan), 3.08 ± 0.32 μm (Pentacam), 3.16 ± 0.29 μm (Galilei), 3.10 ± 0.31 μm (Sirius), 3.13 ± 0.30 μm (Atlas/Visante) and 3.48 ± 0.65 μm (IOL master). Intraobserver and Interobserver Cronbach alpha-test showed a very good reliability coefficient (>0.90) in all the measurements in all the systems.Using the Pentacam as reference the Interdevice reliability coefficient was very good for the rest of the devices (>0.90) but not for the IOL master where the reliability coefficient was low (less than 0.70).

Conclusions: : Anterior Chamber Depth readings with the SST, the three SIS systems and the OCT showed very good correlation and high reproducibility. Nevertheless differences between the inter device measurement were significant when comparing the pentacam with the IOL master, but not with the rest of the systems, this could mean that the IOL master ACD measurement may be not accurate enough for clinical screening, and surgical decision, specially with Phakic IOLs.

Keywords: refractive surgery: corneal topography • refractive surgery: comparative studies • refractive surgery: other technologies