Corneal dioptric power and astigmatism: A comparison between colourcolour light-emitting diode based (Cassini™) and Scheimpflug technology (Pentacam™) topography

Abstract Aim To determine the agreement and to compare the measurements obtained from a colour light-emitting diode based (Cassini™) and Scheimpflug (Pentacam™) based topography in the evaluation of the anterior, posterior, and total corneal power and astigmatism. Methods A total of 30 eyes from 30 healthy patients were consecutively measured using Pentacam™ and Cassini™. The main evaluated parameters were the anterior, posterior, and total dioptric power, and a power vector analysis of the astigmatism. The agreement between both devices was analyzed using the intraclass correlation coefficient (ICC) and performing Bland–Altman plots. The comparison of means was performed using paired Student t -test. Results The agreement between both devices when comparing the anterior and total corneal dioptric power was very high (ICC > 0.85), but not when studying the posterior cornea (ICC   0.78), but was poor for the corneal posterior surface (ICC  p  > 0.05), but Pentacam™ obtained higher values for posterior and total surfaces ( p Conclusion Both devices were highly comparable when studying the anterior cornea, but the agreement was poor-moderate when measuring posterior cornea. Therefore, the data obtained by both topographers are not interchangeable.