Comparison of Refractive Power and Astigmatism between Digital Keratometer and Autorefractor

ABSTRACT

PURPOSE: To compare the corneal refraction, astigmatism, and corneal marking for toric intraocular lens measured with a VERION® Image Guided System and an autorefractor in order to precisely determine the toric intraocular lens target. METHODS: The medical records of 29 eyes of 29 patients were retrospectively reviewed to compare the corneal refraction, axis, and amount of astigmatism measured with a VERION® Image Guided System and an autorefractor. We compared the difference in marked axis for toric intraocular lenses as measured by a VERION Digital Marker and a manual marker. RESULTS: The average corneal refraction and amount of astigmatism were greater with the VERION® Image Guided System than with the autorefractor. The average difference in axis of astigmatism was 9.62°. The difference in axis of astigmatism in patients with more than 1.0 D of astigmatism (18 eyes) was 2.82 ± 2.27°, while that in patients with less than 1.0 D of astigmatism (11 eyes) was 20.27 ± 28.14°. The average difference in marked axis for toric intraocular lens measured by the VERION® Digital Marker and manual marker was 2.50° (0°-9.27°). CONCLUSIONS: The corneal refraction and amount of astigmatism were significantly higher with the VERION® Image Guided System, so careful concern and comparison of surgical outcomes between the two devices is needed in biometry.