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ERIC Number: EJ996230
Record Type: Journal
Publication Date: 2012-Dec
Pages: 6
Abstractor: ERIC
Reference Count: 19
ISBN: N/A
ISSN: ISSN-0145-482X
Preferred Retinal Loci Relationship to Macular Scotomas: A 10-Year Comparison
Schoessow, Kimberly A.; Fletcher, Donald C.; Schuchard, Ronald A.
Journal of Visual Impairment & Blindness, v106 n11 p745-750 Dec 2012
Age-related maculopathy is the leading cause of vision loss among adults in developed countries, and its prevalence is expected to double over the next decade. The two forms of age-related maculopathy--exudative and nonexudative--are capable of affecting the macula, with potential symptoms including decreased contrast sensitivity, decreased visual acuity, abnormal adaptation to the dark, and central or pericentral scotomas. When a central scotoma impairs the ability of the fovea to distinguish detail, one or more preferred retinal loci (PRL), also known as pseudo-foveas, naturally develop at eccentric retinal locations and become the new points of fixation. The location of the PRL varies from person to person, as does the ability to maintain steady fixation with the PRL and to use it for reading and activities of daily living. Fletcher and Schuchard (1997) reported the results of a study examining patterns of PRL ability and location relative to macular scotomas. They mapped dense scotomas and determined the location of the PRL in 1,339 eyes in 825 persons with a scanning laser ophthalmoscope during a standard low vision rehabilitation evaluation. Fletcher and Schuchard created a scoring system to measure the pursuit ability, fixation stability, and saccadic ability of the PRL. They determined the characteristics of dense scotomas within 2.5 degrees of the PRL or fovea. Of the 1,339 eyes, 84% (1,130) demonstrated an established PRL, ranging in size from 1.0 degrees to 9.0 degrees in diameter, and 82.5% had a central dense scotoma. The PRL had no dense scotomas on any border in 14.8% of the eyes. It had one, two, or three borders with a dense scotoma in 39.7%, 19.0%, and 9.0% of the eyes, respectively. Ring scotomas, bordering the PRL on four borders, were present in 17.4% of the eyes. Of the eyes with one scotomatous border, most had a field defect located either superior (39.0%) or to the right (33.7%). It was less common for the eyes to have field defects to the left or inferior, with 19.9% and 7.5% of the eyes, respectively. This report presents a 10-year comparison of these previous findings. It examines whether the PRL characteristics of persons with low vision remained steady over the ensuing decade. Changes in PRL and visual field characteristics among persons with low vision over time could have implications for the approaches of low vision rehabilitation professionals to training in eccentric viewing and other rehabilitation techniques. (Contains 4 figures and 1 table.)
American Foundation for the Blind. 11 Penn Plaza Suite 300, New York, NY 10001. Tel: 800-232-5463; Tel: 212-502-7600; e-mail: afbinfo@afb.net; Web site: http://www.afb.org/store
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Location: California