title: The amblyopia treatment study visual acuity testing protocol.
abstract: OBJECTIVE
  To evaluate the reliability of a new visual acuity testing protocol for children using isolated surrounded HOTV optotypes.
  
  
  METHODS
  After initial pilot testing and modification, the protocol was evaluated using the Baylor-Video Acuity Tester (BVAT) to present isolated surrounded HOTV optotypes. At 6 sites, the protocol was evaluated for testability in 178 children aged 2 to 7 years and for reliability in a subset of 88 children. Twenty-eight percent of the 178 children were classified as having amblyopia.
  
  
  RESULTS
  Using the modified protocol, testability ranged from 24% in 2-year-olds to 96% in 5- to 7-year-olds. Test-retest reliability was high (r = 0.82), with 93% of retest scores within 0.1 logMAR unit of the initial test score. The 95% confidence interval for an acuity score was calculated to be the score +/-0.125 logMAR unit. For a change between 2 acuity scores, the 95% confidence interval was the difference +/-0.18 logMAR unit.
  
  
  CONCLUSIONS
  The visual acuity protocol had a high level of testability in 3- to 7-year-olds and excellent test-retest reliability. The protocol has been incorporated into the multicenter Amblyopia Treatment Study and has wide potential application for standardizing visual acuity testing in children.
authors.affiliation: Mayo Clinic, Ophthalmology West 7, Rochester, MN 55905, USA. holmes.jonathan@mayo.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Holmes
authors.forename: R W
authors.initials: RW
authors.lastname: Beck
authors.forename: M X
authors.initials: MX
authors.lastname: Repka
authors.forename: D A
authors.initials: DA
authors.lastname: Leske
authors.forename: R T
authors.initials: RT
authors.lastname: Kraker
authors.forename: R C
authors.initials: RC
authors.lastname: Blair
authors.forename: P S
authors.initials: PS
authors.lastname: Moke
authors.forename: E E
authors.initials: EE
authors.lastname: Birch
authors.forename: R A
authors.initials: RA
authors.lastname: Saunders
authors.forename: R W
authors.initials: RW
authors.lastname: Hertle
authors.forename: G E
authors.initials: GE
authors.lastname: Quinn
authors.forename: K A
authors.initials: KA
authors.lastname: Simons
authors.forename: J M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000550:Amblyopia / Q000503:physiopathology / Q000628:therapy*; D001285:Atropine / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D006801:Humans; D009184:Mydriatics / Q000627:therapeutic use; D015203:Reproducibility of Results; D012683:Sensory Deprivation; D014787:Vision Tests / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D009184:Mydriatics; D001285:Atropine