title: Precision of NIDEK OPD-scan measurements.
abstract: OBJECTIVE
  To evaluate the repeatability of wavefront measurements using the NIDEK OPD-Scan.
  
  
  METHODS
  A total of 179 eyes from 90 healthy volunteers (57 women and 33 men) with no corneal or lenticular pathology and normal visual acuity were enrolled in this study. Mean patient age was 39 years (range: 17 to 85 years). All patients underwent four consecutive measurements by one examiner with the NIDEK OPD-Scan. Total, corneal, and internal wavefront errors were measured and calculated with the device, using slit retinoscopy. Repeatability of the measurements was evaluated for spherical aberration, coma, and trefoil.
  
  
  RESULTS
  The repeatability test revealed a good result for all three higher order aberrations evaluated. The best repeatability values were found for total aberrations, followed by internal and corneal aberrations.
  
  
  CONCLUSIONS
  The NIDEK OPD-Scan has good precision in the wavefront measurement of total, corneal, and internal optical aberrations.
authors: International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Germany. mike.holzer@med.uni-heidelberg.de
authors: Mike P
authors: MP
authors: Holzer
authors: Susanne
authors: S
authors: Goebels
authors: Gerd U
authors: GU
authors: Auffarth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea / Q000473:pathology*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000473:pathology*; D015203:Reproducibility of Results; D014792:Visual Acuity