title: New Scheimpflug Dynamic In Vivo Curve Analyses to Characterize Biomechanical Changes of the Cornea After Cross-linking for Progressive Keratoconus.
abstract: OBJECTIVE
  To evaluate the effect of corneal cross-linking (CXL) in progressive keratoconus by applying in vivo static and dynamic Scheimpflug analyses.
  
  
  METHODS
  In this longitudinal retrospective study, corneal topography and tomography (Pentacam HD) and dynamic Scheimpflug-based biomechanical analyses (CorvisST [CST]) of 24 eyes of 24 patients with progressive keratoconus before and 6 months after CXL were reviewed. New dynamic curve analyses, provided by Oculus Optikgeräte, were performed to analyze corneal dynamics throughout the entire response to the CST air puff impulse.
  
  
  RESULTS
  Besides subtle changes of topography and tomography, only the CorvisST predefined parameters peak distance (-0.5 mm) and radius of the intended cornea (+0.5 mm; P < .05) demonstrated statistically significant differences 6 months after CXL. Using new dynamic curve analyses, additional distinct changes of the corneal biomechanical characteristics after CXL were noted.
  
  
  CONCLUSIONS
  Published results of corneal biomechanical changes after CXL for progressive keratoconus based on single, predefined CST parameters are inconsistent. The new dynamic curve analyses demonstrate distinct changes of the biomechanical properties of the cornea and might therefore be the next step in understanding in vivo analyses of corneal biomechanics.
authors.forename: Johannes
authors.initials: J
authors.lastname: Steinberg
authors.forename: Andreas
authors.initials: A
authors.lastname: Frings
authors.forename: Aiham
authors.initials: A
authors.lastname: Mousli
authors.forename: Maria K
authors.initials: MK
authors.lastname: Casagrande
authors.forename: Vasyl
authors.initials: V
authors.lastname: Druchkiv
authors.forename: Toam
authors.initials: T
authors.lastname: Katz
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Linke
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000503:physiopathology*; D003319:Corneal Stroma / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D014054:Tomography; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin