title: Rarebit perimetry: normative values and test-retest variability.
abstract: BACKGROUND
  We aim to establish normative values and evaluate test-retest variability for the central and foveal field tests of version 4 of rarebit perimetry.
  
  
  METHODS
  This was a prospective study undertaken in collaboration between Tan Tock Seng Hospital, Singapore, and Singapore Polytechnic.
  
  
  METHODS
  Fifty-four normal subjects were recruited and included in the study.
  
  
  METHODS
  Subjects underwent rarebit perimetry testing, studying the central and foveal fields. All subjects repeated the test within 1 month of the initial visit. The 'mean hit rates' of one eye of every subject were analysed.
  
  
  METHODS
  Mean hit rates of subjects were analysed to establish normative values for the central and foveal fields. Test-retest variability was also analysed.
  
  
  RESULTS
  Overall normative mean hit rates were 86.3 ± 13.95% for the central field and 91.6 ± 6.35% for the foveal field. For every increasing year of age, we found a 0.47% decrease in the central mean hit rates (P < 0.001). Normative mean hit rate for central and foveal fields were 90.6 ± 12.3% and 98.2 ± 3.7% respectively, in 'young' subjects, and 81.9 ± 15.6% and 85.0 ± 9.0% respectively, in 'mature' subjects. We found no significant test-retest variability in the foveal field (P = 0.554). There was significant test-retest variability in the central field (P < 0.001), but the difference was a 3.5 unit mean hit rate increase, which may be clinically significant.
  
  
  CONCLUSIONS
  Rarebit perimetry is repeatable and reliable. We have established normative values for two age groups.
authors: Department of Ophthalmology, Tan Tock Seng Hospital, Singapore. chee_fang@yahoo.com
authors: Chee-Fang
authors: CF
authors: Chin
authors: Leonard W
authors: LW
authors: Yip
authors: Danny C
authors: DC
authors: Sim
authors: Anna C
authors: AC
authors: Yeo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005584:Fovea Centralis / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D011446:Prospective Studies; D015203:Reproducibility of Results; D014792:Visual Acuity; D058609:Visual Field Tests / Q000592:standards*; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult