title: [Biomechanical condition of the cornea as a new indicator for pathological and structural changes].
abstract: OBJECTIVE
  Several methods permit the measurement of geometric parameters of the cornea, but until now biomechanical conditions of the cornea have been ignored (e.g. in refractive corneal surgery). Besides the geometric condition, biomechanical properties of the cornea have been shown to influence applanation measurement of intra-ocular pressure (IOP) and epidemiological studies have identified corneal thickness as an independent risk factor for the development and progression of glaucoma. The aim of this investigation was to characterize the biomechanical properties of the cornea using the ocular response analyzer (ORA).
  
  
  METHODS
  The ocular response analyzer (ORA) is a new method available for non-contact measurement of the biomechanical properties of the cornea. We evaluated the reproducibility of measurements, the difference between static and dynamic factors and the impact of independent factors (e.g. IOP, age, CCT, swelling of the cornea) on 2,500 measurements of corneal hysteresis (CH) and corneal resistance factor (CRF).
  
  
  RESULTS
  In a large sample size we observed changes in CH and CRF after refractive surgery procedures (LASIK, UV-A cross-linking, keratoplasty) and in other corneal disorders (keratoconus, corneal dystrophies).
  
  
  CONCLUSIONS
  CRF and CH changes may reflect structural changes of the cornea. Thus, the ORA provides valuable information for a better understanding and characterization of the biomechanical condition of the cornea, especially with regard to diseases such as keratoconus and glaucoma.
authors.affiliation: Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Dresden, Dresden, Deutschland. eberhard.spoerl@uniklinikum-dresden.de
authors.forename: E
authors.initials: E
authors.lastname: Spörl
authors.forename: N
authors.initials: N
authors.lastname: Terai
authors.forename: M
authors.initials: M
authors.lastname: Haustein
authors.forename: A G
authors.initials: AG
authors.lastname: Böhm
authors.forename: F
authors.initials: F
authors.lastname: Raiskup-Wolf
authors.forename: L E
authors.initials: LE
authors.lastname: Pillunat
mesh_terms: D001696:Biomechanical Phenomena; D003315:Cornea / Q000473:pathology* / Q000503:physiopathology*; D003316:Corneal Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity