title: Assessment of Retinotopic Rod Photoreceptor Function Using a Dark-Adapted Chromatic Perimeter in Intermediate Age-Related Macular Degeneration.
abstract: OBJECTIVE
  We determine the feasibility of using a dark-adapted chromatic (DAC) perimeter to obtain dark-adapted static and dynamic rod function at multiple retinal locations, and compare these functional parameters between subjects with intermediate age-related macular degeneration (AMD) and normal controls.
  
  
  METHODS
  Perimetric dark-adapted retinal sensitivities for the 505 and 620 nm stimuli across 7 retinal locations within the central 12° were repeatedly measured after exposing to a single photobleach in 22 intermediate AMD subjects and 8 controls. The sensitivities for each stimulus at 20 minutes after bleach and the sensitivity difference between the stimuli were used to determine static rod function. Sensitivities for the 505 nm stimulus at various times within the initial 20 minutes after bleach were used to estimate the rod criterion time to determine rod function dynamics. The static and dynamic rod functional parameters were compared between AMD and control eyes.
  
  
  RESULTS
  Compared to the control eyes, AMD eyes had a reduction in retinal sensitivities for the 505 nm (P < 0.001) and 620 nm (P < 0.001) stimuli, a reduction in sensitivity difference (P < 0.001), and an increased in rod criterion time (P < 0.001). Region within the central 6° appeared to be the most defective and AMD eyes with reticular pseudodrusen (RPD) seemed to have worse function than eyes without RPD.
  
  
  CONCLUSIONS
  It is feasible to use a DAC perimeter to study dark-adapted static and dynamic rod-mediated function at multiple retinal loci. Static and dynamic rod function were abnormal in intermediate AMD and more so in eyes with RPD, particularly within the central 6° retina.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Rogan G
authors.initials: RG
authors.lastname: Fraser
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Rose
authors.initials: R
authors.lastname: Tan
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Lauren N
authors.initials: LN
authors.lastname: Ayton
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Emily
authors.initials: E
authors.lastname: Caruso
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Robyn H
authors.initials: RH
authors.lastname: Guymer
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Surgery (Ophthalmology), The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Chi D
authors.initials: CD
authors.lastname: Luu
mesh_terms: D000368:Aged; D003623:Dark Adaptation / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D010775:Photic Stimulation; D012160:Retina / Q000000981:diagnostic imaging; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D041623:Tomography, Optical Coherence; D058609:Visual Field Tests / Q000295:instrumentation*; D014794:Visual Fields