RELIABILITY OF THE HOYA AR570 AUTOREFRACTOR

Title RELIABILITY OF THE HOYA AR570 AUTOREFRACTOR
Author, Co-Author Craig Adams, Mark Bullimore, Robert Fusaro, Russell Cotteral, Joy Sarver, Andrew Graham
Topic
Year
1994
Day
Monday
Program Number
3:00 pm
Room
San Diego Ballroom A
Affiliation
Abstract Auto-refractors are increasingly used to provide a starting point for subjective examinations. We investigated the reliability of a new auto-refractor, the Hoya AR570, as part of an ongoing evaluation of their utility. We recruited 86 subjects, aged 10 to 60 years, by mailing inquiries to 500 randomly selected subjects who had received examinations at the University of California Optometric Eye Center during the first two months of 1994. Contact lens wearers, optometry students, patients with acuities worse than 20/30 in either eye, and individuals with a history of systemic diseases affecting refractive error were excluded. Each subject was examined by two clinicians during their visit. The first clinician obtained five autorefractor readings for each eye (which were later averaged), performed a balanced subjective refraction (with spherical masking lenses in the phoropter), and repeated the autorefractor measurements. This protocol was then repeated by a second clinician. Clinicians were randomized as to testing order and masked to autorefractor results and previous spectacle prescriptions. To quantify the auto-refractor's reliability, we employed mixed model analyses of variance to estimate the appropriate variance components while accounting for the correlation among, for example, repeated measurements of the same eye. All reliability estimates refer to spherical equivalent refractions. We estimate that the average difference between auto-refractor readings, taken by two different optometrists, is 0.02 DS (standard error = 0.02; 95% of differences fall between -0.36 and +0.40 DS). The average difference between the two optometrists' subjective refractions is -0.12 DS (standard error = 0.03; 95% of differences fall between -0.90 and +0.65 DS). Finally, the average difference between the subjective refraction and the auto-refractor reading (performed by the same optometrist) is -0.07 DS (standard error = 0.03; 95% of differences fall between -0.86 and +0
Affiliation of Co-Authors
Outline