title: Comparison of optotypes of Amsterdam Picture Chart with those of Tumbling-E, LEA symbols, ETDRS, and Landolt-C in non-amblyopic and amblyopic patients.
abstract: OBJECTIVE
  To compare optotypes of the Amsterdam Picture Chart (APK) with those of Landolt-C (LC), Tumbling-E (TE), ETDRS and LEA symbols (LEA), to assess their reliability in measuring visual acuity (VA).
  
  
  METHODS
  We recruited healthy controls with equal VA and amblyopes with ≥2 LogMAR lines interocular difference. New logarithmic charts were developed with LC, TE, ETDRS, LEA, and APK with identical size and spacing (four optotypes) between optotypes. Charts were randomly presented at 5 m under DIN EN ISO 8596 and 8597 conditions. VA was measured with LC (LC-VA), TE, ETDRS, LEA, and APK, using six out of ten optotypes answered correctly as threshold.
  
  
  RESULTS
  In 100 controls aged 17-31, LC-VA was -0.207 ± SD 0.089 LogMAR. Visual acuity measured with TE differed from LC-VA by 0.021 (positive value meaning less recognizable), with ETDRS 0.012, with Lea 0.054, and with APK 0.117. In 46 amblyopic eyes with LC-VA <0.5 LogMAR, the difference was for TE 0.017, for ETDRS 0.017, for LEA 0.089, and for APK 0.213. In 13 amblyopic eyes with LC-VA ≥0.5 LogMAR, the difference was for TE 0.122, ETDRS 0.047, LEA 0.057, and APK 0.019. APK optotypes had a lower percentage of passed subjects at each LogMAR line compared to Landolt-C. The 11 APK optotypes had different thresholds.
  
  
  CONCLUSIONS
  Small APK optotypes were recognized worse than all other optotypes, probably because of their thinner lines. Large APK optotypes were recognized relatively well, possibly reflecting recognition acuity. Differences between the thresholds of the 11 APK optotypes reduced its sensitivity further.
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, Dr. Molewaterplein 50-60, 3015 GE, Rotterdam, The Netherlands, simonsz@compuserve.com.
authors.forename: O
authors.initials: O
authors.lastname: Engin
authors.forename: D D G
authors.initials: DD
authors.lastname: Despriet
authors.forename: H M
authors.initials: HM
authors.lastname: van der Meulen-Schot
authors.forename: A
authors.initials: A
authors.lastname: Romers
authors.forename: X
authors.initials: X
authors.lastname: Slot
authors.forename: M Tjon Fo
authors.initials: MT
authors.lastname: Sang
authors.forename: M
authors.initials: M
authors.lastname: Fronius
authors.forename: H
authors.initials: H
authors.lastname: Kelderman
authors.forename: H J
authors.initials: HJ
authors.lastname: Simonsz
mesh_terms: D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009988:Orthoptics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012684:Sensory Thresholds; D014787:Vision Tests / Q000295:instrumentation*; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult