Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Young's modulus in normal corneas and the effect on applanation tonometry

Hamilton-Maxwell, Kirsten E. and Pye, David C. 2008. Young's modulus in normal corneas and the effect on applanation tonometry. Optometry and Vision Science 85 (6) , pp. 445-450. 10.1097/OPX.0b013e3181783a70

Full text not available from this repository.

Abstract

Objectives. To determine the statistically normal range of corneal Young's modulus in young healthy eyes in vivo, and to establish if this variation has a clinically significant influence on intraocular pressure (IOP) measurement using applanation tonometry. Methods. Central corneal curvature, central corneal thickness (CCT), and applanation IOP (Goldmann tonometer) were measured using standard clinical techniques in one eye of 100 normal human subjects (22.0 ± 2.9 years) in vivo. The Orssengo-Pye algorithm was used to calculate the corneal Young's modulus of these experimental subjects, and to produce a theoretical model of potential errors in Goldmann applanation tonometry estimates of IOP due to variations of Young's modulus and CCT. Results. Corneal Young's modulus was 0.29 ± 0.06 MPa [95% confidence interval (CI) 0.17 to 0.40 MPa]. According to the Orssengo-Pye model, the relationship between Young's modulus and the error in applanation IOP is linear; the slope was 23 mm Hg per MPa. An increase from the minimum to the maximum value of the calculated limits of agreement (95% CI) of Young's modulus caused a variation in applanation IOP of 5.35 mm Hg. The anticipated error at the extremes of the limits of agreement (95% CI) of CCT was similar at 4.67 mm Hg. Conclusion. Physiological variations in corneal Young's modulus may cause clinically significant errors in Goldmann applanation tonometry estimates of IOP.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Optometry and Vision Sciences
Subjects: R Medicine > RE Ophthalmology
Uncontrolled Keywords: cornea, biomechanics, tonometry, Goldmann, applanation, intraocular pressure
Publisher: Lippincott, Williams & Wilkins
ISSN: 1040-5488
Last Modified: 04 Jun 2017 04:15
URI: http://orca.cf.ac.uk/id/eprint/35447

Citation Data

Cited 55 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item