title: Short- and long-term repeatability of Visioptic Alcon EyeMap (Visioptic EH-270) corneal topographer on normal human corneas.
abstract: The purpose of this study was to examine the short-term and long-term (6 months) repeatability of the Alcon EyeMap (Visioptic EH-270)a Computerized Corneal Topographer on normal eyes. Three measurements were taken on both eyes of 39 subjects with the corneal topographer. Both eyes of seven of these subjects were measured 6 months later in order to evaluate long-term repeatability. The data showed that short-term reliability of the instrument was acceptable with a mean standard deviation (SD) < or = 0.5 D up to 3 mm (6-mm optical zone) from the center of the normal cornea. Beyond that distance, SD's of repeated measures increased systematically, making the results less useful. Long-term repeatability of the instrument over a 6-month period was acceptable clinically, although statistically significant differences were noted.
authors.affiliation: College of Optometry, University of Houston, Texas, USA.
authors.forename: M
authors.initials: M
authors.lastname: Younes
authors.forename: R
authors.initials: R
authors.lastname: Boltz
authors.forename: N E
authors.initials: NE
authors.lastname: Leach
authors.forename: H
authors.initials: H
authors.lastname: Bedell
mesh_terms: D000328:Adult; D003315:Cornea / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods / Q000592:standards*; D008875:Middle Aged; D015203:Reproducibility of Results