title: Comparative evaluation of the Allergan Humphrey 570 and Canon RK-1 autorefractors: II. Objective autorefraction in pseudophakes.
abstract: Fifty patients (50 eyes) with posterior chamber intraocular lenses and a best corrected visual acuity of at least 6/12 were studied. The Allergan-Humphrey 570 (AH-570) and Canon RK-1 autorefractors were compared in terms of ease of operation, time taken and their accuracy relative to clinical refraction. Both the autorefractors were equally easy to operate but the AH-570 was quicker. The AH-570 had a higher percentage of eyes within 11 degrees of clinically determined cylinder axis while the Canon RK-1 had a higher percentage of patients within 0.51 diopters of spherical equivalence, sphere power and cylinder power as determined by clinical refraction. This difference in the accuracy of objective autorefraction was not statistically significant; the clinical significance is uncertain.
authors.affiliation: Department of Ophthalmology, District General Hospital, Southport, England.
authors.forename: J R
authors.initials: JR
authors.lastname: Villada
authors.forename: P S
authors.initials: PS
authors.lastname: Raj
authors.forename: A E
authors.initials: AE
authors.lastname: Lewis
authors.forename: P W
authors.initials: PW
authors.lastname: Joyce
authors.forename: A
authors.initials: A
authors.lastname: Watson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D009885:Ophthalmology / Q000295:instrumentation*; D011446:Prospective Studies; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis*