A comparison of the EH-270 corneal topographer with conventional keratometry

The Marco Model-1 keratometer was compared for accuracy and precision with the El Hage Corneal Topography System (EH-270). Five consecutive readings of three steel calibration balls (40.50 D, 42.50 D, 44.75 D), one PMMA hemisphere (48.00 D), and 14 eyes (seven patients) were obtained using each instrument. Keratometry was found to be statistically more accurate and precise for measuring the two steeper steel balls and the hemisphere. Values obtained from patients demonstrated excellent correlation between keratometry and the EH-270. Although more variability was observed in measuring corneas greater than 43.00 D using the EH-270, we found these differences to be clinically acceptable. The EH-270 has a number of clinical advantages.