title: Reproducibility of intraocular lens decentration and tilt measurement using a clinical Purkinje meter.
abstract: OBJECTIVE
  To determine the reproducibility of intraocular lens (IOL) decentration and tilt measurements with a new Purkinje meter instrument.
  
  
  METHODS
  Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.
  
  
  METHODS
  After pupil dilation, images of pseudophakic eyes with a plate-style IOL (Akreos Adapt) were obtained using a recently developed Purkinje meter. Intraocular lens decentration and tilt were evaluated by analyzing the captured images using a semiobjective method by marking the reflexes in the images and automatic calculation using a dedicated software program. In study 1, examiner 1 examined the eyes first followed by examiner 2. Ten minutes later, examiner 1 performed a second measurement, after which the intraexaminer and interexaminer reproducibility were determined. In study 2, a Purkinje meter was used to measure pseudophakic eyes with slitlamp finding of clinical IOL decentration, IOL tilt, or both. The results were compared with retroillumination photographs and slitlamp findings.
  
  
  RESULTS
  In study 1, there was high intraexaminer reproducibility for decentration (r = 0.95) and tilt (r = 0.85) and high interexaminer reproducibility for decentration (r = 0.84) and tilt (r = 0.75). In study 2, even in extreme cases of decentration and/or tilt, the Purkinje meter measurements were possible and appeared to correlate well with slitlamp findings.
  
  
  CONCLUSIONS
  Acquisition of images in pseudophakic eyes with the Purkinje meter was simple and rapid. The method was highly reliable for 1 examiner and between 2 examiners.
authors.affiliation: Department of Pathology, Institute of Ophthalmology, University College London, and Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nishi
authors.forename: Nino
authors.initials: N
authors.lastname: Hirnschall
authors.forename: Alja
authors.initials: A
authors.lastname: Crnej
authors.forename: Vinod
authors.initials: V
authors.lastname: Gangwani
authors.forename: Juan
authors.initials: J
authors.lastname: Tabernero
authors.forename: Pablo
authors.initials: P
authors.lastname: Artal
authors.forename: Oliver
authors.initials: O
authors.lastname: Findl
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000175:diagnosis; D015350:Contrast Sensitivity / Q000502:physiology; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D018918:Phacoemulsification; D010781:Photography / Q000295:instrumentation*; D011475:Prosthesis Failure; D019591:Pseudophakia / Q000209:etiology; D012029:Refraction, Ocular / Q000502:physiology; D015203:Reproducibility of Results; D014792:Visual Acuity / Q000502:physiology