Evaluation of Lens Hardness in Cataract Surgery using High-Frequency Ultrasonic Parameters in Vitro

Chih Chung Huang, Hossein Ameri, Charles DeBoer, Adrian P. Rowley, Xiaochen Xu, Lei Sun, Shyh Hau Wang, Mark S. Humayun, K. Kirk Shung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

30 Citations (Scopus)


Ultrasonic parameters of sound velocity and frequency-dependent attenuation ranging from 25 to 45 MHz were measured for the purpose of evaluating the hardness of lenses in cataract surgery (phacoemulsification). Measurements were performed with a 35-MHz ultrasonic transducer on porcine lenses in which artificially cataracts were induced. The hardness of the cataractous lens was also evaluated by mechanical measurement of its elastic properties. The results indicated that the ultrasonic attenuation coefficients in normal porcine lenses were approximately 4.49 ± 0.05 (mean ± SD) and 6.32 ± 0.04 dB/mm at 30 and 40 MHz, respectively. The development progression of the cataracts resulted in the attenuation coefficient increasing linearly to 7.36 ± 0.25 and 11.1 ± 0.92 dB/mm, respectively, corresponding to an increase of Young's modulus from 2.6 to 101.2 kPa. The sound velocity concomitantly increased from 1639.8 ± 4.2 to 1735.6 ± 10.4 m/s. Evaluation of the relationship between the phacoemulsification energy level and ultrasonic parameters in vitro by surgeons revealed that both the attenuation coefficient and sound velocity were linearly correlated with the phacoemulsification energy (r = 0.941 and 0.915, respectively). These results showed that measuring high-frequency ultrasonic parameters provides surgeons with good capability and reproducibility for selecting the optimal energy level for phacoemulsification. (E-mail: j648816n@ms23.hinet.net).
Original languageEnglish
Pages (from-to)1609-1616
Number of pages8
JournalUltrasound in Medicine and Biology
Issue number10
Publication statusPublished - 1 Oct 2007
Externally publishedYes


  • Attenuation coefficient
  • Cataract
  • High-frequency ultrasound
  • Phacoemulsification
  • Sound velocity

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Biophysics
  • Acoustics and Ultrasonics

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