title: Clinical experience with the Tracey technology wavefront device.
abstract: OBJECTIVE
  In refractive surgery, measuring the total ocular profile of refraction gives more vital information than measuring the cornea alone. We report the first clinical experiments with spatially resolved refractometry using ray tracking principles. Tracey technology was developed in Ukraine by the Institute of Biomedical Engineering in cooperation with the Vardinoyannion Eye Institute of Crete.
  
  
  METHODS
  The Tracey-1 device was evaluated in comparison with conventional videokeratoscopes. Seven pseudophakic eyes of 7 patients and two phakic eyes were measured thirty (30) consecutive times (consecutively) each to test reproducibility. Measurements were provided in zones 0 to 5 (6) mm. For each zone, parameters of astigmatism were calculated and mean value and standard deviation were derived.
  
  
  RESULTS
  Standard deviation on the order of 0.14 D was derived.
  
  
  CONCLUSIONS
  The Tracey Technology wavefront device provides information on the refraction distribution at the first principal plane of the ocular optical system. For the instrument to provide measurements that are directly applicable to clinical practice, the data should be transposed to the corneal plane. The Tracey device can be utilized for the measurement of accommodative amplitude and range. Further development of the instrument is requred to increase its accuracy.
authors.affiliation: Department of Ophthalmology, Vardinoyannion Eye Institute of Crete, University of Crete, Greece. ophadmin@med.uoc.gr
authors.forename: I G
authors.initials: IG
authors.lastname: Pallikaris
authors.forename: S I
authors.initials: SI
authors.lastname: Panagopoulou
authors.forename: V V
authors.initials: VV
authors.lastname: Molebny
mesh_terms: D000065:Accommodation, Ocular; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation; D006801:Humans; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results