Identification of preferred retinal loci with the Heidelberg Retina Tomograph II in patients with age-related macular degeneration.
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.
Markowitz
Samuel N
SN
Low Vision Service, University Health Network, Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada. snm1@rogers.com
Eskander
Emad
E
Markowitz
Michelle
M
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