title: The Effect of Age on the Temporal Summation of Achromatic Perimetric Stimuli.
abstract: OBJECTIVE
  To examine the temporal summation of a Goldmann III-sized stimulus under the conditions of standard automated perimetry in healthy participants of varying age.
  
  
  METHODS
  Twenty-seven healthy individuals of varying age (24-80 years) were tested. Achromatic contrast thresholds were measured for seven 0.48° diameter (near Goldmann III) spot stimuli of varying presentation duration (1-24 frames, 1.8-191.9 ms) at 8.8° eccentricity in the visual field along the 45°, 135°, 225°, and 315° meridians. All stimuli were displayed on a CRT display with a background set to 10 cd/m2. Iterative two-phase regression analysis was used to estimate the critical duration from each localized temporal summation function.
  
  
  RESULTS
  A significant decrease in contrast sensitivity for all stimulus durations examined in this study was observed with increasing age in both the superior and inferior hemifield (P < 0.001). Despite this, no significant change in the critical duration was observed as a function of age in either the superior (r² = 9.1 × 10⁻⁹, P = 0.99) or inferior hemifield (r² = 2.4 × 10⁻⁵, P = 0.98).
  
  
  CONCLUSIONS
  Age-related changes in the visual system, although leading to a reduction in contrast sensitivity, are not accompanied by a change in temporal summation for a detection task with an achromatic 0.48° diameter spot stimulus. This is important to know when proceeding to examine temporal summation changes in diseases like glaucoma.
authors.affiliation: National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom 2Vision Science Research Group, School of Biomedical Sciences, University o.
authors.forename: Pádraig J
authors.initials: PJ
authors.lastname: Mulholland
authors.affiliation: School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom.
authors.forename: Tony
authors.initials: T
authors.lastname: Redmond
authors.affiliation: National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom.
authors.forename: David F
authors.initials: DF
authors.lastname: Garway-Heath
authors.affiliation: Vision Science Research Group, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, United Kingdom.
authors.forename: Margarita B
authors.initials: MB
authors.lastname: Zlatkova
authors.affiliation: National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom 2Vision Science Research Group, School of Biomedical Sciences, University o.
authors.forename: Roger S
authors.initials: RS
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000503:physiopathology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D012684:Sensory Thresholds / Q000502:physiology*; D013702:Temporal Lobe / Q000503:physiopathology; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult