title: Hardness and ultrasonic characteristics of the human crystalline lens.
abstract: OBJECTIVE
  To evaluate the relationship between hardness of the human crystalline lens and its acoustic characteristics.
  
  
  METHODS
  St. George's Hospital Medical School, University of London, London, United Kingdom.
  
  
  METHODS
  Cataractous lenses from patients who had extracapsular cataract surgery were studied for hardness and ultrasonic characteristics. Lens hardness was assessed with an automated guillotine. Ultrasound velocity and attenuation were measured with a scanning acoustic macroscope using the pulse transmission reflection method.
  
  
  RESULTS
  Thirty-seven lenses from 37 patients (mean age 75.5 years) were evaluated. Lens hardness was associated with ultrasound attenuation (r = 0.65, P <.0001) and attenuation frequency gradient (r = 0.67, P <.0001). The correlation of hardness with mean ultrasound velocity was not significant (r = 0.22, P =.2).
  
  
  CONCLUSIONS
  The attenuation of ultrasound waves by the human crystalline lens correlated with its hardness. Ultrasonography can be used to evaluate lens hardness.
authors.affiliation: Department of Ophthalmology, St. George's Hospital Medical School, London, UK. tabandeh@eye1.eye.ufl.edu
authors.forename: H
authors.initials: H
authors.lastname: Tabandeh
authors.forename: M
authors.initials: M
authors.lastname: Wilkins
authors.forename: G
authors.initials: G
authors.lastname: Thompson
authors.forename: D
authors.initials: D
authors.lastname: Nassiri
authors.forename: A
authors.initials: A
authors.lastname: Karim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D002387:Cataract Extraction; D019245:Compressive Strength; D006801:Humans; D066298:In Vitro Techniques; D007908:Lens, Crystalline / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D014463:Ultrasonography