title: Repeatability of visual function measures in age-related macular degeneration.
abstract: OBJECTIVE
  To assess repeatability of visual function measures in patients with early, intermediate or late age-related macular degeneration (AMD) without active neovascular disease in the study eye, but active neovascular AMD in the fellow eye.
  
  
  METHODS
  One hundred subjects from an ongoing trial were screened for this study in which their LogMAR acuity, contrast sensitivity and reading performance were assessed using standardised protocols by trained optometrists. The same measures were repeated one month later and repeatability of the visual functions assessed.
  
  
  RESULTS
  Data from 83 subjects satisfied inclusion criteria for analysis. Coefficient of repeatability was 14.9 letters for LogMAR visual acuity , 7.2 letters for Pelli Robson contrast sensitivity, 0.72 for LogMAR reading acuity, 110.4 words/ min for reading speed and 0.67 for LogMAR critical print size. Intraclass correlation coefficients allowed comparison between measures and were found to be 0.96 for LogMAR visual acuity, 0.93 for contrast sensitivity, 0.75 for LogMAR reading acuity, 0.79 for reading speed and 0.74 for LogMAR critical print size. Coefficients of variation were 9.4 %, 10.7 %, 48.4 %, 28.4 % and 31.8 % respectively.
  
  
  CONCLUSIONS
  We found coefficients of repeatability that concurred with previous studies demonstrating variability of visual functions in patients with AMD. In addition, we found intraclass correlation coefficients to be better with visual acuity and contrast sensitivity than with measures of reading performance.
authors.affiliation: Manchester Royal Eye Hospital, Manchester Academic Health Science Centre, Manchester, UK.
authors.forename: Tariq
authors.initials: T
authors.lastname: Aslam
authors.forename: Sajjad
authors.initials: S
authors.lastname: Mahmood
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Balaskas
authors.forename: Niall
authors.initials: N
authors.lastname: Patton
authors.forename: Rajeev G
authors.initials: RG
authors.lastname: Tanawade
authors.forename: Shi Zhuan
authors.initials: SZ
authors.lastname: Tan
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Roberts
authors.forename: Jeremy
authors.initials: J
authors.lastname: Parkes
authors.forename: Paul N
authors.initials: PN
authors.lastname: Bishop
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011932:Reading; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology*; D057135:Wet Macular Degeneration / Q000188:drug therapy / Q000503:physiopathology*
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab