title: Design and Clinical Evaluation of a Handheld Wavefront Autorefractor.
abstract: OBJECTIVE
  To introduce a novel autorefractor design that is intended to be manufacturable at low cost and evaluate its performance in measuring refractive errors.
  
  
  METHODS
  We developed a handheld, open-view autorefractor (the "QuickSee" [QS]) that uses a simplified approach to wavefront sensing that forgoes moving parts and expensive components. Adult subjects (n = 41) were recruited to undergo noncycloplegic refraction with three methods: (1) a QS prototype, (2) a Grand Seiko WR-5100K (GS) autorefractor, and (3) subjective refraction (SR). Agreements between the QS and GS were evaluated using a Bland-Altman analysis. The accuracy of both autorefractors was evaluated using SR as the clinical gold standard.
  
  
  RESULTS
  The spherical equivalent powers measured from both autorefractors correlate well with SR, with identical correlation coefficients of r = 0.97. Both autorefractors also agree well with each other, with a spherical equivalent power 95% confidence interval of ±0.84 diopters (D). The difference between the accuracy of each objective device is not statistically significant for any component of the power vector (p = 0.55, 0.41, and 0.18, for M, J0, and J45, respectively). The spherical and cylindrical powers measured by the GS agree within 0.25 D of the SR in 49 and 82% of the eyes, respectively, whereas the spherical and cylindrical powers measured by the QS agree within 0.25 D of the SR in 74 and 87% of the eyes, respectively.
  
  
  CONCLUSIONS
  The prototype autorefractor exhibits equivalent performance to the GS autorefractor in matching power vectors measured by SR.
authors.affiliation: *PhD †OD, PhD Madrid-MIT M+Visión Consortium, Massachusetts Institute of Technology, Cambridge, Massachusetts (NJD, SRD, DL, EL); Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland (NJD); New England College of Optometry, Boston, Massachusetts (FAV-D, FT); Instituto de Óptica "Daza de Valdés," Consejo Superior de Investigaciones Científicas, Madrid, Spain (CD, SM); and Instituto de Investigaciones Biomédicas "Alberto Sols," UAM/CSIC, Madrid, Spain (EL).
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Durr
authors.forename: Shivang R
authors.initials: SR
authors.lastname: Dave
authors.forename: Fuensanta A
authors.initials: FA
authors.lastname: Vera-Diaz
authors.forename: Daryl
authors.initials: D
authors.lastname: Lim
authors.forename: Carlos
authors.initials: C
authors.lastname: Dorronsoro
authors.forename: Susana
authors.initials: S
authors.lastname: Marcos
authors.forename: Frank
authors.initials: F
authors.lastname: Thorn
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lage
mesh_terms: D000328:Adult; D057108:Corneal Wavefront Aberration / Q000175:diagnosis; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results; D014787:Vision Tests / Q000295:instrumentation*; D015348:Vision, Binocular / Q000502:physiology; D055815:Young Adult