Correlation between Keratometric Measurements Obtained by the VERION Image Guided System, Optical Biometry (IOL Master) and Corneal Topography in Egyptian Cataractous Patients

Abstract Background: Recent applications and developments have increased the accuracy of preoperative corneal shape and refractive power evaluations prior to phacoemulsification with intraocular lens (IOL) implantation. The toric IOL has been shown to have substantial efficacy in correcting astig-matism. Accurate keratometry values (K-values) can be used as part of surgical planning for corneal incision design, astigmatic keratotomy (AK), the management of surgery-induced astigmatism (SIA), and correcting postoperative residual astigmatism. Several previous studies have compared corneal astigmatism measurements obtained using a range of keratometers. Aim of Study: To measure the correlation coefficient for the keratometric measurements of VERION Image Guided System, an optical biometry (IOLMaster) and corneal topog-raphy (Oculus Keratograph) in Egyptian cataractous patients. Patients and Methods: A forty-five eyes of cataractous patients were included in this cross-sectional observational study which was approved by the Ethics Committees of the Ain Shams University Hospitals. Results: This study demonstrated excellent correlations between the Keratograph and each of VERION and IOLMaster for the Km values, good correlation for the axis and astigma-tism between Keratograph and VERION, and moderate cor-relation between Keratograph and IOLMaster for axis and astigmatism. The agreement of keratometry measurements (Km and astigmatism) obtained from VERION versus Kera-tograph ranged between –1.3845 to 2.0783 and –1.0616 to 1.2913) respectively and for IOLMaster versus Keratograph are 0.7528 to 1.2510 and –0.9396 to 1.2463) respectively. Conclusion: No differences in km, astigmatism and axis were observed between the VERION, IOLMaster and Kera-tograph. The keratometery values obtained with the VERION system were slightly steeper than those obtained with other devices except for astigmatism.