Contact-based stiffness sensing of human eye.
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.
Kurita
Yuichi
Y
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
Kempf
Roland
R
Iida
Yoshichika
Y
Okude
Jumpei
J
Kaneko
Makoto
M
Mishima
Hiromu K
HK
Tsukamoto
Hidetoshi
H
Sugimoto
Eiichiro
E
Katakura
Seiki
S
Kobayashi
Ken
K
Kiuchi
Yoshiaki
Y
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*