title: Adult discrimination performance for pediatric acuity test optotypes.
abstract: OBJECTIVE
  To compare adult discrimination performance on nine pediatric visual acuity tests to determine the consistency of optotype design.
  
  
  METHODS
  After their binocular acuity was measured with each test, eight adult observers (mean age, 27 years ± 6.3 SD; three emmetropes and five corrected myopes) were shown isolated single optotypes from the Allen figures, HOTV, Landolt C, Lea Numbers, Lea Symbols, Lighthouse, Patti Pics, Precision Vision numbers, and Tumbling E tests. A one-interval, two-alternative forced-choice protocol was used at a single distance, and each optotype was paired with all optotypes from the same chart. Confusion matrices were generated for each test and Luce's (1963) biased-choice model was fit to each matrix to derive measures of pairwise similarity between the optotypes.
  
  
  RESULTS
  The acuities from the Allen figures (P < 0.001) and HOTV (P = 0.029) were the only ones to differ significantly from the reference Landolt C. The choice-model analyses of the confusion matrices revealed that the Allen figures, HOTV, Lighthouse, Patti Pics, and Precision Vision numbers tests all had significant differences in discriminability of optotypes within the test.
  
  
  CONCLUSIONS
  Pediatric acuity test optotypes are not all equally discriminable to adult observers with normal vision and no ocular disorders. The current data suggest that care must be taken when presenting limited numbers of optotypes, as is done with young patients.
authors: Indiana University School of Optometry, Bloomington, Indiana rcandy@indiana.edu., USA.rcandy@indiana.edu
authors: T Rowan
authors: TR
authors: Candy
authors: Sylvia R
authors: SR
authors: Mishoulam
authors: Robert M
authors: RM
authors: Nosofsky
authors: Velma
authors: V
authors: Dobson
mesh_terms: D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000175:diagnosis* / Q000503:physiopathology; D002648:Child; D004192:Discrimination, Psychological; D058453:Emmetropia / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D014787:Vision Tests / Q000379:methods*; D014792:Visual Acuity; D055815:Young Adult