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Highlight: Late Breaking Scientific News in Corneal Topography - 2 Pages

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Catalogue excerpts

Late Breaking Scientific News in Corneal Topography Conclusion: Color LED topography is the most precise and consistently accurate among the three topographers used in determining corneal aberrations. Cassini produces reliably interpretable measurements even for case where other instruments fail. Preliminary Comparator Study Results show Cassini Color LED Corneal Topography to consistently produce reliable results for both normal and abnormal cornea, and for lower and higher order aberrations as well. Cassini overcomes the shortcomings of both Placido ring topography and Scheimpflug photography. In a clinical study, Cassini’s performance was compared with Scheimpflug Photography and Placido based corneal topography in measuring corneal aberrations in patients with both reported (e.g. PKP) and no reported corneal abnormalities. Eyes from all patients were imaged three consecutive times on each instrument. Preliminary results show that Cassini’s performance is more accurate and precise than both other instruments for both normal and abnormal eyes. In addition, in a measurement comparison of PKP cornea, the relative error (in diopter) for all aberrations was seen to be lowest for Cassini. Both Placido ring topography as well as Scheimpflug photography showed varying performance depending on the aberration. This is in line with known restrictions of each technique. Based on this results it is expected that Cassini provides a more accurate ‘corneal cast’ resulting in better patient outcomes upon corneal corrections and remodulation. In addition, Cassini’s output may prove to be a valuable contribution in reducing the need for glasses upon cataract surgery, as the contribution of the cornea in overall refraction can now be accurately assessed. >> Placido based corneal topography has the worse relative accuracy and measures statistically different corneal astigmatism. Scheimpflug based topography measures statistically different spherical aberration compared to Placido based corneal topography and color LED topography. olor LED topography has the best precision. It is C better compared to Scheimpflug based topography and the differences for trefoil and quadrafoil aberrations are statistically significant. ut of 14 patients that could be measured by the O Cassini, 5 and 6 patients have unreliable measurements from Scheimpflug photography and Placido ring topography respectively. One patient could not be imaged on all instruments, due to severely abnormal cornea.

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Equivalent Defocus (Diopter) Precision4,50 comparison between Color LED Topography, Scheimpflug Cassini OPD Pentacam Photography and Placido based corneal topography in measur4,00 ing corneal aberrations (N=5 eyes with no corneal abnormality). 3,50 Kruskal-Wallis Test and Mann-Whitney Test were performed to 3,00 p=0,01 compare the groups of measurements. Equivalent Defocus (Diopter) Relative accuracy: comparative corneal aberration measurements between Color LED Topography, Scheimpflug Photography and Placido based corneal topography (N=8 PKP eyes). Kruskal-Wallis Test was performed to compare...

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