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Logo for the Journal of Rehab R&D
Volume 43 Number 5, September/October 2006
Pages 749 — 760

Abstract - Retinal locus for scanning text

George T. Timberlake, PhD;1-2* Manoj K. Sharma, MD;1 Susan A. Grose, BS;1 Joseph H. Maino, OD, FAAO1-2

1Kansas City Veterans Affairs Medical Center, Kansas City, MO; 2Department of Ophthalmology, University of Kansas Medical Center, Kansas City, KS
Abstract — A method of mapping the retinal location of text during reading is described in which text position is plotted cumulatively on scanning laser ophthalmoscope retinal images. Retinal locations that contain text most often are the brightest in the cumulative plot, and locations that contain text least often are the darkest. In this way, the retinal area that most often contains text is determined. Text maps were plotted for eight control subjects without vision loss and eight subjects with central scotomas from macular degeneration. Control subjects' text maps showed that the fovea contained text most often. Text maps of five of the subjects with scotomas showed that they used the same peripheral retinal area to scan text and fixate. Text maps of the other three subjects with scotomas showed that they used separate areas to scan text and fixate. Retinal text maps may help evaluate rehabilitative strategies for training individuals with central scotomas to use a particular retinal area to scan text.
Key words: eccentric viewing, fixation, fixation PRL, preferred retinal locus, reading, reading rehabilitation, retinal function mapping, scanning laser ophthalmoscope, text scanning, text-scanning PRL

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