Comparability of an image-guided system with other instruments in measuring corneal keratometry and astigmatism.

Abstract

PURPOSE:

To test whether keratometry (K) and astigmatism measurements provided by the Verion Reference Unit (an image-guided system) compared well with the Tonoref II automated tonometer-refractometer, IOLMaster partial coherence interferometry (PCI) biometer, AL-Scan optical biometer, Pentacam rotating Scheimpflug camera, and OPD Scan III wavefront aberrometer.

SETTING:

Augenklinik am Neumarkt, Cologne, Germany.

DESIGN:

Retrospective case series.

METHODS:

Patients having routine cataract surgery had standard preoperative assessment including biometry measurement with all study devices. The K values, power of astigmatism, axis, and the lens power of an imaginary intraocular lens (IOL) were analyzed for each device.

RESULTS:

One hundred five eyes of 62 patients with a mean age of 68.5 years ± 11.9 (SD) (range 27.2 to 89.7 years) were included in the study. The mean differences in flat K readings between the image-guided system and the tonometer-refractometer, PCI biometer, optical biometer (2.4 and 3.2 mm), rotating Scheimpflug camera, and wavefront aberrometer were -0.03 mm, 0.00 mm, 0.01 mm (both 2.4 and 3.2 mm), -0.03 mm, and -0.01 mm, respectively (P < .001). Differences were slightly greater for steep K readings as follows: -0.04 mm, -0.01 mm, -0.02 (optical biometer 2.4 mm), -0.03 mm (optical biometer 3.2 mm), -0.04 mm, and -0.06 mm, respectively (P < .001). The calculated power of an imaginary IOL from the study devices fell within 0.28 diopter of one another (P > .05).

CONCLUSIONS:

The image-guided system compared well with and provided astigmatism measurements similar to those of currently available diagnostic measurement devices. This system can aid appropriate preoperative IOL power calculations.

FINANCIAL DISCLOSURES:

Drs. Schultz, Oberheide, and Kermani have received honoraria from Alcon Pharma GmbH for corporate presentations.

• Authors: Michael Schultz, Uwe Oberheide, Omid Kermani
• Journal: Journal of cataract and refractive surgery (J Cataract Refract Surg) Vol. 42 Issue 6 Pg. 904-12 (06 2016) ISSN: 1873-4502 [Electronic] United States
• PMID: 27373398 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Topics

• Adult
• Aged
• Aged, 80 and over
• Astigmatism (diagnostic imaging)
• Biometry
• Cornea (diagnostic imaging)
• Female
• Germany
• Humans
• Lenses, Intraocular
• Male
• Middle Aged
• Prospective Studies
• Reproducibility of Results
• Retrospective Studies