title: Contact-based stiffness sensing of human eye.
abstract: Goldmann applanation tonometry is commonly used for measuring intraocular pressure (IOP) to diagnose glaucoma. However, the measured IOP by conventional applanation tonometry is valid only under the assumption that all subjects have the same structural eye stiffness. This paper challenges in vivo measurement of eye stiffness with a noninvasive approach and investigates individual differences of eye stiffness. Eye stiffness is defined by the applied force and displacement of the cornea. The displacement is detected based on captured images by a high resolution camera. The experimental results show that the measured stiffness nicely matches the analytical result that is derived from a simple spherical deformation model with an internal pressure. However, some subjects have different eye stiffness even with the same IOP. IOP with abnormal stiffness may be over/underestimated by conventional applanation tonometry. The proposed eye stiffness measurement can help detect the misestimated eye and it contributes to the early detection of glaucoma.
authors.affiliation: Graduate School of Information Science, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama-chou, Ikoma, Nara 630-0101, Japan. kurita@is.naist.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kurita
authors.forename: Roland
authors.initials: R
authors.lastname: Kempf
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Iida
authors.forename: Jumpei
authors.initials: J
authors.lastname: Okude
authors.forename: Makoto
authors.initials: M
authors.lastname: Kaneko
authors.forename: Hiromu K
authors.initials: HK
authors.lastname: Mishima
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Tsukamoto
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Sugimoto
authors.forename: Seiki
authors.initials: S
authors.lastname: Katakura
authors.forename: Ken
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kiuchi
mesh_terms: D003198:Computer Simulation; D003315:Cornea / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004548:Elasticity; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014065:Tonometry, Ocular / Q000379:methods*