To compare corneal astigmatism, keratometry and corneal higher order aberrations between the light emitting diode corneal topography analyzer and Scheimpflug Imager. Methods

This prospective study involved 45 patients (45 eyes) who visited Seoul St. Mary's hospital before cataract surgery from June 7, 2017, to August 2, 2017. For each eye, keratometry, astigmatism and its axis of cornea, higher-order aberrations were evaluated with a Scheimpflug Imager (Pentacam HR®, Oculus, Wetzlar, Germany) and a color-LED corneal topographer (Cassini®, i-Optics, Den Haag, The Netherlands). Results

Astigmatism magnitude measured using Cassini® and Pentacam® showed no statistically differences but anterior and total astigmatic axes were significantly different, as measured by the two devices ( p < 0.05). Anterior and total mean keratometry were statistically significantly different, as measured by the two devices ( p < 0.05). J0 and J45 vectors of anterior and total cornea were statistically different ( p < 0.05). In addition, Cassini® and Pentacam® showed discrepancies between total corneal astigmatism, total J0 and J45 vectors. Corneal anterior spherical aberration, vertical and horizontal coma, and oblique and horizontal trefoil aberrations were not statistically different between the two devices. Conclusions

Astigmatic axes obtained from the two devices based on different principles showed statistically significant differences. Astigmatism magnitude was not statistically different but showed a discrepancy between the two devices.