title: Accommodative facility in eyes with and without myopia.
abstract: OBJECTIVE
  To compare accommodative facility in eyes with myopia to that in eyes with emmetropia or hyperopia and to determine whether accommodative facility can be used to predict an association with myopia.
  
  
  METHODS
  In the Sydney Myopia Study, year-1 school children (6.7 +/- 0.4 years) were assessed for accommodative facility at distance (3 m) and near (33 cm) with semiautomated flippers. Spherical equivalent refractive error (RE) was defined as myopia (< or = -0.50 D), emmetropia (> -0.50 D, but < +1.50 D), and hyperopia (> or = +1.50 D) based on postcycloplegia readings. Only right eye data were considered. Differences between groups were analyzed with the Brown-Forsythe F test after adjustment for age and gender. Multiple comparisons were adjusted with the by the Games-Howell
  
  
  METHODS
  
  
  
  RESULTS
  Of the 1328 right eyes assessed, 20 (1.5%) eyes were myopic, 977 (73.6%) were emmetropic, and 331 (24.9%) were hyperopic. At distance, mean facility was less for myopic eyes at 5.5 +/- 2.0 cycles per minute (cpm) in comparison to 6.9 +/- 1.7 cpm for eyes with emmetropia or hyperopia (P = 0.005). Myopic eyes recorded greater positive and negative accommodative response times than did emmetropic or hyperopic eyes (P < 0.05). There were no differences among the groups in near facility. The area under the receiver operating characteristic (ROC) curve for distance facility was 0.692 (P = 0.003, 95% CI, 0.580-0.805).
  
  
  CONCLUSIONS
  Myopic eyes have reduced accommodative facility at distance, and accommodative responsiveness to both positive and negative defocus is slow. However, accommodative facility as a test does not have sufficient power to discriminate eyes with myopia from other refractive errors.
authors.affiliation: Vision Co-operative Research Centre, Level 4 Rupert Myers Building, Sydney, NSW 2052, Australia.
authors.forename: Ashok
authors.initials: A
authors.lastname: Pandian
authors.forename: Padmaja R
authors.initials: PR
authors.lastname: Sankaridurg
authors.forename: Thomas
authors.initials: T
authors.lastname: Naduvilath
authors.forename: Daniel
authors.initials: D
authors.lastname: O'Leary
authors.forename: Deborah F
authors.initials: DF
authors.lastname: Sweeney
authors.forename: Kathryn
authors.initials: K
authors.lastname: Rose
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D019540:Area Under Curve; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D014787:Vision Tests