Sirius Scheimpflug–Placido versus ultrasound pachymetry for central corneal thickness: meta-analysis

Abstract

Background To compare the difference in central corneal thickness (CCT) measurements in normal eyes between a rotating Scheimpflug camera combined with a Placido-disk corneal topographer (Sirius, CSO, Italy) and ultrasound pachymetry (USP). Methods A systematic literature search was conducted for relevant studies published on PubMed, Medline, EMBASE, and the Cochrane Library and ClinicalTrials.gov from inception to August 1st, 2019. Primary outcome measures were CCT measurements between Sirius and USP. A random effects model was used to pool CCT measurements. Results A total of twelve studies involving 862 eyes were included in this meta-analysis. The meta-analysis found CCT measurements between Sirius and USP to be statistically significantly different (P < 0.0001). The mean difference between Sirius and USP was −11.26 μm with a 95% confidence interval (CI) (−16.92 μm, −5.60 μm). The heterogeneity was I2 = 60% (P = 0.004). Conclusion CCT measurements with the Sirius Scheimpflug-Placido topographer were statistically significantly lower than USP. However, it may be argued that the mean difference of 11.26 μm is not a clinically significant difference.

Monitoring of central corneal thickness after phacoemulsification—comparison of statical and rotating Scheimpflug pachymetry, and spectral-domain OCT

“…Most of these publications compared the results of measurements taken with the present gold standard, ultrasound pachymetry. Jin et al [10] and Jorge et al [22] demonstrated excellent accordance in measurements taken by a Scheimpflug camera with ultrasound pachymetry. Especially Jorge et al [22] underlined that a feasible compensation of the results remained not possible.…”

“…Most studies compared the results with the gold standard, ultrasound pachymetry. Various authors have found excellent correlations of CCT measured with Scheimpflug diagnostics and ultrasound pachymetry [10,12,22,25,38,42] . Similar results were found for OCT [12,15,29,34] .…”

“…This results in corneal swelling and thereby an increase in central corneal thickness (CCT) as an expression of endothelial decompensation. Extent and decrease of corneal swelling prove the endothelial recovery and compensation of its function [3,[6][7][8][9][10][11][12][13][14] . A high preoperative endothelial cell count (ECC) does not guarantee an uncomplicated intra-and postoperative course and a low ECC does not make corneal complications not inevitable.…”

Twelve-month outcomes of a new refractive lenticular extraction procedure

“…It seems more that 280-300µm is more common nowadays. 36 275µm ist „just“ +10% above 250µm as a safety margin, the 25µm extra safety margin can be understood as a reserve for potential undercorrections of up to ∼1.5D; but at the same time is ∼50% (half the thickness) of the average normal central corneal pachymetry; 37 finally, since the introduction of percentage tissue altered (PTA), a PTA of ∼40% has been proposed as the cutoff value for enhanced ectasia risk, 38 considering 480µm (according to the german “Kommission Refraktive Chirurgie der DOG und des BVA”) 39 as the minimum pachymetry suitable for lamellar refractive surgery (whether LASIK or lenticule extraction); an RST of 275µm would represent a 42.7% PTA.…”

Changes in Central Corneal Thickness, Corrected Intraocular Pressure, and Iridocorneal Angle in Unilateral Acute Anterior Uveitis

“…Patients underwent corneal topography with bon Sirius corneal topographer and tomographer (CSO, Italy) which combines placido disk topography with Scheimpflug tomography of the anterior segment (Jin et al, 2021). The CCT was recorded, the ICA was measured in all the quadrants and the average in both eyes was recorded.…”