TY - JOUR
T1 - The impact of intraocular pressure on elastic wave velocity estimates in the crystalline lens
AU - Park, Suhyun
AU - Yoon, Heechul
AU - Larin, Kirill V.
AU - Emelianov, Stanislav Y.
AU - Aglyamov, Salavat R.
N1 - Publisher Copyright:
© 2017 Institute of Physics and Engineering in Medicine.
PY - 2017/1/19
Y1 - 2017/1/19
N2 - Intraocular pressure (IOP) is believed to influence the mechanical properties of ocular tissues including cornea and sclera. The elastic properties of the crystalline lens have been mainly investigated with regard to presbyopia, the age-related loss of accommodation power of the eye. However, the relationship between the elastic properties of the lens and IOP remains to be established. The objective of this study is to measure the elastic wave velocity, which represents the mechanical properties of tissue, in the crystalline lens ex vivo in response to changes in IOP. The elastic wave velocities in the cornea and lens from seven enucleated bovine globe samples were estimated using ultrasound shear wave elasticity imaging. To generate and then image the elastic wave propagation, an ultrasound imaging system was used to transmit a 600 µs pushing pulse at 4.5 MHz center frequency and to acquire ultrasound tracking frames at 6 kHz frame rate. The pushing beams were separately applied to the cornea and lens. IOP in the eyeballs was varied from 5 to 50 mmHg. The results indicate that while the elastic wave velocity in the cornea increased from 0.96 ± 0.30 m s−1 to 6.27 ± 0.75 m s−1 as IOP was elevated from 5 to 50 mmHg, there were insignificant changes in the elastic wave velocity in the crystalline lens with the minimum and the maximum speeds of 1.44 ± 0.27 m s−1 and 2.03 ± 0.46 m s−1, respectively. This study shows that ultrasound shear wave elasticity imaging can be used to assess the biomechanical properties of the crystalline lens noninvasively. Also, it was observed that the dependency of the crystalline lens stiffness on the IOP was significantly lower in comparison with that of cornea.
AB - Intraocular pressure (IOP) is believed to influence the mechanical properties of ocular tissues including cornea and sclera. The elastic properties of the crystalline lens have been mainly investigated with regard to presbyopia, the age-related loss of accommodation power of the eye. However, the relationship between the elastic properties of the lens and IOP remains to be established. The objective of this study is to measure the elastic wave velocity, which represents the mechanical properties of tissue, in the crystalline lens ex vivo in response to changes in IOP. The elastic wave velocities in the cornea and lens from seven enucleated bovine globe samples were estimated using ultrasound shear wave elasticity imaging. To generate and then image the elastic wave propagation, an ultrasound imaging system was used to transmit a 600 µs pushing pulse at 4.5 MHz center frequency and to acquire ultrasound tracking frames at 6 kHz frame rate. The pushing beams were separately applied to the cornea and lens. IOP in the eyeballs was varied from 5 to 50 mmHg. The results indicate that while the elastic wave velocity in the cornea increased from 0.96 ± 0.30 m s−1 to 6.27 ± 0.75 m s−1 as IOP was elevated from 5 to 50 mmHg, there were insignificant changes in the elastic wave velocity in the crystalline lens with the minimum and the maximum speeds of 1.44 ± 0.27 m s−1 and 2.03 ± 0.46 m s−1, respectively. This study shows that ultrasound shear wave elasticity imaging can be used to assess the biomechanical properties of the crystalline lens noninvasively. Also, it was observed that the dependency of the crystalline lens stiffness on the IOP was significantly lower in comparison with that of cornea.
KW - Acoustic radiation force
KW - Crystalline lens
KW - Elastic wave
KW - Elastography
KW - Intraocular pressure
UR - http://www.scopus.com/inward/record.url?scp=85036613018&partnerID=8YFLogxK
U2 - 10.1088/1361-6560/aa54ef
DO - 10.1088/1361-6560/aa54ef
M3 - Article
C2 - 27997379
AN - SCOPUS:85036613018
SN - 0031-9155
VL - 62
SP - N45-N57
JO - Physics in Medicine and Biology
JF - Physics in Medicine and Biology
IS - 3
ER -