Dynamic measurement of intraocular pressure using a mechanical model of the human eye.

M. Hien, T. H. Yang, R. L. Reuben, R. W. Else

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)

Abstract

Heightened intraocular pressure (IOP) is not always indicative of glaucoma, but is an important risk factor for the progression of certain types of eye damage not obviously felt by the sufferer. A number of measurement systems have been devised in the past to measure the IOP by applying force or pressure to the cornea, but past studies have shown that the cornea thickness and its curvature have a significant effect on measurements which may ultimately lead to clinical misdiagnosis. A cyclic strain controlled dynamic probing measurement system has been developed using an indenter of diameter 3.06 mm operating at actuation frequencies of between 0.1 Hz and 4 Hz and displacements up to 1 mm. The cyclic strain is actuated by a linear stage with a load cell and indenter coupled in series. The load cell records the resultant cyclic force where the dynamic modulus is expressed as amplitude ratio and phase lag. The mechanical eye model consists of a silicone membrane that can be varied in thickness and it is distended hydraulically to simulate a range of IOP. A pressure sensor measures the dynamic IOP within the system which will be compared against the dynamic modulus. The relationship between the mechanical properties and the physical properties of the membrane will be established in order to develop a probe which can be used clinically taking into account the effects of corneal stiffness and hydraulic behaviour of the eye. The preliminary study reported here a significant increase in amplitude ratio and mean ratio with increasing the frequency similar to the behaviour found in biological materials and gelatin.

Original languageEnglish
Title of host publicationMedicine Meets Engineering
EditorsJ Hammer, M Nerlich, S Dendorfer
Place of PublicationAmsterdam
PublisherIOS Press
Pages112-122
Number of pages11
Volume133
ISBN (Print)978-1-58603-828-1
Publication statusPublished - 2008
Event2nd Conference on Applied Biomechanics - Regensburg, Germany
Duration: 13 Jun 200715 Jun 2007

Publication series

NameStudies in Health Technology and Informatics
PublisherI O S PRESS
Volume133
ISSN (Print)0926-9630

Conference

Conference2nd Conference on Applied Biomechanics
CountryGermany
CityRegensburg
Period13/06/0715/06/07

Keywords

  • Central Cornea Thickness CCT
  • TONOMETRY
  • LASER
  • Dynamic Measurement
  • Intra Ocular Pressure IOP
  • OPEN-ANGLE GLAUCOMA

Cite this

Hien, M., Yang, T. H., Reuben, R. L., & Else, R. W. (2008). Dynamic measurement of intraocular pressure using a mechanical model of the human eye. In J. Hammer, M. Nerlich, & S. Dendorfer (Eds.), Medicine Meets Engineering (Vol. 133, pp. 112-122). (Studies in Health Technology and Informatics; Vol. 133). IOS Press.