Comparison of anterior and posterior elevation map measurements between 2 Scheimpflug imaging systems

Abstract

In refractive surgery candidates with healthy eyes, the elevation map measurements with the single-Scheimpflug system were significantly different from those with the dual-Scheimpflug system in most aspects and therefore may lead to misinterpretation of clinical data that could alter clinical decisions if the 2 imaging systems are considered interchangeable.

Assessment of central corneal thickness in normal, keratoconus, and post-laser in situ keratomileusis eyes using Scheimpflug imaging, spectral domain optical coherence tomography, and ultrasound pachymetry

“…22 These differences are relevant given the increasing number of AS-OCT and Scheimpflug instruments available. 37 The instruments we evaluated use different methods to generate corneal thickness data, and detailed information on the algorithms that the Scheimpflug rotating camera uses to generate the data is not available. 4 The exact image-processing algorithms used in AS-OCT and Scheimpflug imaging are proprietary, and internal processing algorithms might be based on different (ie, higher resolution or contrast) data sets.…”

Assessment of anterior and posterior corneal indices using two Scheimpflug analyzers

“…A previously published study showed a difference between the single and dual Scheimpflug systems, with values obtained by the former system (Pentacam) being higher than those obtained by the latter (Galilei) (1) . We believe that the difference was primarily due to the diff erent BFS diameters pre-set for each system: 9 mm in the single Scheimpflug system and 8 mm in the dual Scheimpflug system.…”

“…Previous studies have evaluated the agreement between Scheimpflug devices; however, different best-fit sphere (BFS) diameters were used in both devices (1) or only elevation data were compared between the Dual Scheimpflug Analyzer and a Scanning Slit-beam imaging system (2) . Comparisons using different BFS would alter the elevation data obtained by the single Scheimpflug system (compared with the dual Scheimpflug system) because the reference is flatter.…”

Effects of Birth Weight on Anterior Segment Measurements in Full-Term Children Without Low Birth Weight by Dual-Scheimpflug Analyzer

“…The Galilei Dual-Scheimpflug Analyzer is equipped with two Scheimpflug cameras, both of which provide accurate pachymetry across the entire cornea by delivering precise measurements of the anterior chamber, even when the camera is de-centered due to micro-movements of the eye. 19 The Galilei Dual-Scheimpflug Analyzer is also integrated with placido-disc-based topography, which conveys accurate topographic data not only from the entire cornea. but also from >122,000 data points/scan.…”

“…but also from >122,000 data points/scan. 19,20 In the present study, we investigated the impact of birth weight on anterior segment structures measured by Galilei Dual-Scheimpflug Analyzer in healthy fullterm preschoolers without low birth weight.…”