title: Test-Retest Variability of Fundus-Tracked Perimetry at the Peripapillary Region in Open Angle Glaucoma.
abstract: OBJECTIVE
  To examine the association between the measured level and local gradient of visual sensitivity on the magnitude of test-retest variability of its measurements at the peripapillary region using fundus-tracked perimetry in eyes with glaucoma.
  
  
  METHODS
  A total of 30 participants with open angle glaucoma underwent three examinations in one eye on fundus-tracked perimetry using a stimulus pattern that sampled the peripapillary region densely. Factors associated with the magnitude of test-retest variability at each location were examined.
  
  
  RESULTS
  There was no significant change in average pointwise sensitivity (PWS) between tests 1 and 2 (P = 0.855), but a significant reduction between tests 2 and 3 (P < 0.001). Therefore, all subsequent analyses were performed only between tests 1 and 2. Multivariate analyses revealed that the magnitude of test-retest variability at a given location was significantly associated with its average sensitivity and gradient of sensitivity relative to the immediately adjacent locations (P ≤ 0.001), meaning that locations with low levels of sensitivity (4-18 dB) with low gradients of sensitivity (<2 dB/location) had a 90% test-retest limit of ±5.83 dB, compared to a limit of ±10.65 dB in areas of high gradients of sensitivity (>4 dB/location).
  
  
  CONCLUSIONS
  On a pointwise basis, the test-retest variability of visual sensitivity in glaucoma is not just related to its measured level, but also its local gradient when using fundus-tracked perimetry. Locations with low sensitivity do not necessarily demonstrate very high test-retest variability, depending on the local uniformity of visual field damage.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia 2Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia.
authors.forename: Allison M
authors.initials: AM
authors.lastname: McKendrick
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia 2Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Xavier
authors.initials: X
authors.lastname: Hadoux
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia 2Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Jennifer C Fan
authors.initials: JC
authors.lastname: Gaskin
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia 2Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Ghee Soon
authors.initials: GS
authors.lastname: Ang
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia 2Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Marc G
authors.initials: MG
authors.lastname: Sarossy
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia 2Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Crowston
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005654:Fundus Oculi; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D015203:Reproducibility of Results; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*