title: Identification of preferred retinal loci with the Heidelberg Retina Tomograph II in patients with age-related macular degeneration.
abstract: BACKGROUND
  To determine the suitability and accuracy of the Heidelberg Retina Tomograph II (HRT II) scanning laser ophthalmoscope for identification of preferred retinal loci (PRLs) in patients with age-related macular degeneration (AMD).
  
  
  METHODS
  Fixation location was assessed prospectively in 9 eyes by 3 methods: the HRT II, a retinal camera equipped with a fixation target, and grid macular perimetry. Two testing protocols were also used: using an HRT protocol for disc location analysis and an HRT protocol for macular fixation analysis.
  
  
  RESULTS
  Locations of PRLs on retinal quadrants identified by all 3 methods were identical in 7 of 9 (78%) cases (McNemar chi(2) test, p = 0.48, kappa = 0.78, at 95% confidence interval) with both testing protocols. Eccentric location coordinates for PRLs were not significantly different by testing modality when using either the disc location protocol (R = 0.47, p = 0.20 [t7 = 1.4], y = 0.29x + 3.29) or the macular fixation protocol (R = 0.44, p = 0.23 [t7 = 1.3], y = 0.31x + 3.23).
  
  
  CONCLUSIONS
  Eccentric locations of the optic disc on recorded video frames with the HRT II correspond to eccentric locations of PRLs in patients with AMD.
authors.affiliation: Low Vision Service, University Health Network, Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada. snm1@rogers.com
authors.forename: Samuel N
authors.initials: SN
authors.lastname: Markowitz
authors.forename: Emad
authors.initials: E
authors.lastname: Eskander
authors.forename: Michelle
authors.initials: M
authors.lastname: Markowitz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008268:Macular Degeneration / Q000503:physiopathology*; D008297:Male; D019721:Ophthalmoscopes; D009887:Ophthalmoscopy / Q000379:methods*; D011446:Prospective Studies; D012160:Retina / Q000503:physiopathology*; D014054:Tomography / Q000379:methods; D014741:Video Recording