Open AccessNon-contact determination of intra-ocular pressure in an ex vivo porcine model
Author(s) -
Ari Salmi,
Heikki J. Nieminen,
Daniel Veira Canle,
Edward Hæggström,
Antti Kontiola
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0227488
Subject(s) - ex vivo , glaucoma , biomedical engineering , intraocular pressure , optics , shock wave , spark gap , ophthalmology , materials science , medicine , in vivo , physics , mechanics , microbiology and biotechnology , quantum mechanics , voltage , biology
People suffering from glaucoma often endure high intra-ocular pressure (IOP). Methods for determining IOP either contact the eye or are unpleasant to some patients. There is therefore a need for a rapid and patient friendly non-contacting method to determine IOP. To address this need, we developed a tonometer prototype that employs spark-gap induced shock waves and a laser Doppler vibrometer (LDV) that reads the amplitude of membrane waves. The IOP was first identified from the membrane wave propagation velocity first in a custom-made ocular phantom and was then verified in ex vivo porcine eyes. The time-of-flight (TOF) of the membrane wave travelling on a hemispherical membrane was compared to reference IOP values in the sample obtained with an iCare TA01 tonometer. The shock front was characterized by high speed photography. Within one eye, the method achieved an agreement of 5 mmHg (1.96 standard deviation between the shock wave tonometer and the commercial manometer) and high method-to-method association (Pearson correlation, R 2 = 0.98). The results indicate that the presented method could potentially be developed into a non-contacting technique for measuring IOP in vivo .