title: Evaluation of patient visual comfort and repeatability of refractive values in non-presbyopic healthy eyes.
abstract: OBJECTIVE
  To evaluate the intra-operator repeatability in healthy subjects using the WAM-5500 auto-kerato/refractometer and the iTrace aberrometer, to compare the refractive values and the subjective refraction obtained with both devices and to determine which of these three spherocylindrical corrections allows the subject to achieve the best visual comfort.
  
  
  METHODS
  Forty-two non-presbyopic healthy eyes of 42 subjects were enrolled in this prospective study. Refractive values were compared, evaluating the repeatability, the relationship between the methods and the best visual comfort obtained.
  
  
  RESULTS
  Sphere, cylinder and axis results showed good intraclass correlation coefficients (ICC); the highest ICC was obtained using the spherical refraction with the autorefractometer and the aberrometer, achieving levels of 0.999 and 0.998, respectively. The power vector (PV) was calculated for each refraction method, and the results indicated that there were no statistically significant differences between them (P>0.05). Direct comparison of PV measurements using the three methods showed that aberrometer refraction gave the highest values, followed by the subjective values; the autorefractometer gave the lowest values. The subjective method correction was most frequently chosen as the first selection. Equal values were found for the autorefractometer and the aberrometer as the second selection.
  
  
  CONCLUSIONS
  The iTrace aberrometer and the WAM-5500 auto-kerato/refractometer showed high levels of repeatability in healthy eyes. Refractive corrections with the aberrometer, the autorefractometer and subjective methods presented similar results, but spherocylindrical subjective correction was the most frequently selected option. These technologies can be used as complements in refractive evaluation, but they should not replace subjective refraction.
authors.affiliation: Department of Surgery, Gynaecology and Obstetrics, University of Zaragoza, Zaragoza 50009, Spain ; Aragon Health Sciences Institute, University of Zaragoza, Zaragoza 50009, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Segura
authors.affiliation: Aragon Health Sciences Institute, University of Zaragoza, Zaragoza 50009, Spain ; Department of Applied Physics, University of Zaragoza, Zaragoza 50009, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Sanchez-Cano
authors.affiliation: Aragon Health Sciences Institute, University of Zaragoza, Zaragoza 50009, Spain ; Department of Applied Physics, University of Zaragoza, Zaragoza 50009, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Lopez de la Fuente
authors.affiliation: Aragon Health Sciences Institute, University of Zaragoza, Zaragoza 50009, Spain ; Department of Physiology and Pharmacology, University of Zaragoza, Zaragoza 50009, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Fuentes-Broto
authors.affiliation: Department of Surgery, Gynaecology and Obstetrics, University of Zaragoza, Zaragoza 50009, Spain ; Aragon Health Sciences Institute, University of Zaragoza, Zaragoza 50009, Spain ; Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza 50009, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Pinilla
keywords: aberrometer; autorefractometer; optical correction; repeatability; subjective refraction