title: Intrasession test-retest variability of microperimetry in age-related macular degeneration.
abstract: OBJECTIVE
  To determine the intrasession test-retest variability of microperimetry in participants with age-related macular degeneration (AMD).
  
  
  METHODS
  This study consisted of two separate groups of subjects who had not performed microperimetry previously. In group 1, 30 AMD and 14 control participants performed three microperimetry examinations of a selected eye within one session (test 1 and 2, first pair; test 2 and 3, second pair). Follow-up examination at 6 months was available in 20 AMD participants in group 1, who performed two microperimetry examinations. In group 2, 71 AMD participants performed a short practice examination, then two microperimetry examinations of the right eye (test 1 and 2, first pair) and two of the left eye (test 3 and 4, second pair).
  
  
  RESULTS
  There was a significant improvement in average point-wise sensitivity (PWS) between the first pair of examination in both groups (P < 0.001), but not in the subsequent pair (P ≥ 0.774). This improvement was not observed at the follow-up visit in the subset of AMD participants in group 1 (P = 0.433). The PWS coefficient of repeatability (CoR) for the second pair of examinations was ± 4.12 dB and ± 4.37 dB for AMD participants for group 1 and 2 respectively.
  
  
  CONCLUSIONS
  A significant increase in sensitivity between the first and second test, but not in the subsequent tests, was found for participants who had not performed microperimetry previously. Intrasession test-retest variability can therefore be minimized by discarding the first examination to avoid the influence of a learning effect.
authors.affiliation: Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wu
authors.forename: Lauren N
authors.initials: LN
authors.lastname: Ayton
authors.forename: Robyn H
authors.initials: RH
authors.lastname: Guymer
authors.forename: Chi D
authors.initials: CD
authors.lastname: Luu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014792:Visual Acuity; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields
keywords: age-related macular degeneration; microperimetry; repeatability; test–retest; variability