title: Ocular microfluctuations and videokeratoscopy.
abstract: OBJECTIVE
  We aimed to minimize the effect of ocular microfluctuations during videokeratoscopy to improve the qualitative and quantitative analysis of corneal topography.
  
  
  METHODS
  A technique was developed to measure the tilt, displacement, and cyclotorsion in multiple videokeratographs from the same cornea. This information was used to reposition each videokeratograph according to the average position of a sample of multiple measurements. The corneal topography of 10 subjects was measured 20 times each, using videokeratoscopy.
  
  
  RESULTS
  The root mean square error calculated from difference between single videokeratographs and the average videokeratograph decreased by an average of 24.6% for the 10 subjects' data. The standard deviation of some terms of Zernike polynomials fitted to the cornea was significantly reduced after the procedure.
  
  
  CONCLUSIONS
  The method that we propose can improve the precision performance of videokeratoscopy in multiple measurements of corneal topography.
authors.affiliation: School of Optometry, Contact Lens and Visual Optics Laboratory, Center for Eye Research, Queensland University of Technology, Brisbane, Australia. t.buehren@student.qut.edu.au
authors.forename: Tobias
authors.initials: T
authors.lastname: Buehren
authors.forename: Brenden J
authors.initials: BJ
authors.lastname: Lee
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Collins
authors.forename: D Robert
authors.initials: DR
authors.lastname: Iskander
mesh_terms: D000328:Adult; D003315:Cornea / Q000033:anatomy & histology*; D019781:Corneal Topography / Q000379:methods*; D005133:Eye Movements; D006801:Humans; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity