Assessment of anterior and posterior corneal indices using two Scheimpflug analyzers

Abstract

Purpose: To assess the agreement between the elevation and curvature measurements of the anterior and posterior corneal surfaces obtained using the Galilei Dual Scheimpflug Analyzer and those obtained using the Pentacam single Scheim pflug system. Methods: This prospective, noninterventional, diagnostic study was conducted at the Department of Ophthalmology at the American University of Beirut (Medical Center) and included 60 eyes of 60 consecutive patients. Measurements were obtained using 2 different Scheimpflug analyzers (Galilei and Pentacam). The best-fit sphere was set at 8 mm in both machines. Pachymetry (CCT), anterior elevation (AE) and posterior elevation (PE), and curvature were assessed. Pearson's correlation coefficients, comparison of means, and Bland-Altman plots were used to evaluate agreement between the 2 systems. Results: The average CCT (at the corneal apex) was 533 ± 35 μm and 532 ± 37 μm (p=0.980), the average central AE was 1.25 ± 3.95 μm and 2.

Corneal Higher-Order Aberrations Measurements: Precision of SD-OCT/Placido Topography and Comparison with a Scheimpflug/Placido Topography in Eyes After Small-Incision Lenticule Extraction

“…These include the newly developed MS-39 (Costruzione Strumenti Oftalmici, Florence, Italy) anterior segment-optical coherence tomography (AS-OCT) device, which combines spectral-domain OCT with Placido disk topography (SD/OCT-Placido or MS-39 device), and the Sirius (Costruzione Strumenti Oftalmici) device, which combines a single Scheimpflug camera with Placido disk topography (Scheimpflug-Placido or Sirius device). Both instruments simultaneously measure the anterior, posterior, and total corneal surfaces [11,12]. Several studies have investigated the repeatability, reproducibility, and agreement between corneal thickness and curvature measurements by both technologies [11,[13][14][15][16][17][18][19][20][21], but only a few have focused on corneal HOAs.…”

“…Both instruments simultaneously measure the anterior, posterior, and total corneal surfaces [11,12]. Several studies have investigated the repeatability, reproducibility, and agreement between corneal thickness and curvature measurements by both technologies [11,[13][14][15][16][17][18][19][20][21], but only a few have focused on corneal HOAs. To date, no studies have compared the precision of corneal HOA measurements by the SD/OCT-Placido and the agreement of these two anterior segment imaging technologies in measuring corneal HOAs in eyes with prior SMILE.…”

Anterior Segment Eye Assessment of Refractive Surgery Candidates in the Southeast of Iran

“…First, the assessment of corneal refractive parameters allows examiners to have more control over refractive error progress. CCT considered as a major factor in keratoconus diagnosis (Falavarjani et al, 2010;Fahd et al, 2014), precise IOP measurement, and early detection of open-angle glaucoma (Channa et al, 2009). Anterior chamber parameters could be helpful to IOL power calculation of cataract patients (Shankar et al, 2007).…”

“…Eye movements are recorded and corrected simultaneously. The measurement repeats when scanning process fails the quality specifications (Fahd et al, 2014;Jain & Grewal, 2009;Kent, 2005). All measurements were done by three same experienced technicians.…”