Volume 43 Number 5, September/October 2006
Pages 761 — 770
Abstract - Effects of preferred retinal locus placement on text navigation and
development of advantageous trained retinal locus
Gale R. Watson, MEd, CLVT;1* Ronald A. Schuchard, PhD;1 William R. De l'Aune, PhD;2 Erica Watkins, BA1
1Blind Rehabilitation Service, Rehabilitation Research and Development Center of Excellence for Aging Veterans with Vision Loss, Atlanta Department of Veterans Affairs Medical Center, Decatur, GA; 2Atlanta Research and Education Foundation, Atlanta, GA
Abstract — Sixty readers were evaluated for visual function and text-navigation ability. The visual field and preferred retinal locus (PRL) were measured with a scanning laser ophthalmoscope (SLO). We found significant differences in text-navigation ability based on scotoma and PRL placement. Readers with a PRL to the left of or above a scotoma had significantly less text-navigation abilities. Readers with a PRL to the left of a scotoma tended to misread words with similar beginnings and omit the last word on a line. Readers with a PRL above a scotoma tended to skip a line or reread the same line twice. In a follow-up study, seven subjects with a nonadvantageous PRL quickly developed a trained retinal locus (TRL) during instruction with an SLO. Although the readers developed the TRL in about 15 minutes, they read slower with the TRL than the PRL. This TRL research provides promising pilot data.
Key words: low vision, macular scotoma, preferred retinal locus, reading, rehabilitation, scanning laser ophthalmoscope, text navigation, trained retinal locus, vision rehabilitation, visual impairment.