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Proceedings Paper

Active noncontact tonometer for glaucoma detection
Author(s): Yanmei Han; Peter John Bryanston-Cross; Wing Kai A. Lee; Mark Hero
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Paper Abstract

Glaucoma is an increasingly common cause of visual impairment, and in some cases causes blindness. The approach to develop a low cost and non-contact tonometer for the detection of glaucoma, to replace the Goldmann tonometer used worldwide, is presented in this paper. The new tonometer exploits the vibration property of the cornea - the resonance frequency of the cornea rises with increasing intra-ocular pressure (IOP). An audio frequency signal is used to vibrate the cornea of the eye, the vibration of the cornea is measured using a fibre optic lever probe, and then the IOP can be calculated from the detected resonance frequency of the cornea. The initial PC-version experiment system of the new tonometer has been demonstrated and preliminary testing has been performed, showing a suitable sensitivity in detecting the resonance frequency against the IOP using both the simulated-eye model and the pig’s eye. The initial system has been improved to be suitable for greater than 15mm detecting distance, and the measurement of vibrations of human cornea in-vivo has been carried out. Work is now focusing on increasing the sensitivity of the fibre probe, and reducing the measuring time to less than 1 second.

Paper Details

Date Published: 12 September 2002
PDF: 8 pages
Proc. SPIE 4916, Optics in Health Care and Biomedical Optics: Diagnostics and Treatment, (12 September 2002); doi: 10.1117/12.482946
Show Author Affiliations
Yanmei Han, Univ. of Warwick (United Kingdom)
Peter John Bryanston-Cross, Univ. of Warwick (United Kingdom)
Wing Kai A. Lee, Univ. of Warwick (United Kingdom)
Mark Hero, Coventry and Warwick Hospital (United Kingdom)

Published in SPIE Proceedings Vol. 4916:
Optics in Health Care and Biomedical Optics: Diagnostics and Treatment
Britton Chance; Mingzhe Chen; Gilwon Yoon, Editor(s)

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