title: [Accuracy of the autorefractor power refractor in clinical work--a comparative study].
abstract: BACKGROUND
  The aim of this prospective study was to investigate accuracy and efficiency of the autorefractometer PowerRefractor compared to established autorefractometers and retinoscopy as standard method.
  
  
  METHODS
  150 patients (300 eyes) were examined. Patients were initially (pupil not influenced) analyzed with the Power Refractor (PR (neutral)). After that a examination followed under standardized Cyclopentolat cycloplegia with the Power Refractor (PR (cyclo)), the hand-held Retinomax K-plus (Nikon), the table-top mounted RK-5 (Canon) and retinoscopy.
  
  
  RESULTS
  Deviation from retinoscopy (percentage of values with more than 1 dpt difference/maximal deviation): Sphere: PR (neutral): 66.3 %/8.5 dpt; PR (cyclo): 48 %/5 dpt; RK-5: 26.7 %/4.75 dpt; Retinomax K-plus: 6.7 %/1.25 dpt; Cylinder: PR (neutral): 12 %/6.25 dpt; PR (cyclo): 21 %/4.75 dpt; RK-5: 1.3 %/2.75 dpt; Retinomax K-plus: 2.3 %/2.5 dpt; spherical equivalent: PR (neutral): 44.7 %/7.1 dpt; PR (cyclo): 35.3 %/5.4 dpt; RK-5: 9 %/4.5 dpt; Retinomax K-plus: 1.3 %/1.,4 dpt; error of entire refraction: PR (neutral): 62.7 %/7.8 dpt; PR (cyclo): 61.3 %/7.3 dpt; RK-5: 24 %/4,5 dpt; Retinomax K-plus: 14.7 %/3.6 dpt
  
  
  CONCLUSIONS
  The best accuracy compared to retinoscopy had Retinomax K-plus followed by RK-5. PowerRefractor had the biggest deviations of the tested devices. PowerRefractor may be a usefull device for screening small children and handicapped people because of the one meter observing distance. For a precise refraction especially in children a retinoscopy under cycloplegic conditions is still necessary.
authors.affiliation: Universitätsaugenklinik Rostock. michael.schittkowski@med.uni-rostock.de
authors.forename: M
authors.initials: M
authors.lastname: Schittkowski
authors.forename: S
authors.initials: S
authors.lastname: Hucks-Sievers
authors.forename: H
authors.initials: H
authors.lastname: Krentz
authors.forename: R
authors.initials: R
authors.lastname: Guthoff
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D042261:Retinoscopes; D042262:Retinoscopy / Q000379:methods*; D012680:Sensitivity and Specificity