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ERIC Number: EJ996213
Record Type: Journal
Publication Date: 2012-Sep
Pages: 7
Abstractor: ERIC
Reference Count: 22
ISBN: N/A
ISSN: ISSN-0145-482X
A Simplified Method of Identifying the Trained Retinal Locus for Training in Eccentric Viewing
Vukicevic, Meri; Le, Anh; Baglin, James
Journal of Visual Impairment & Blindness, v106 n9 p555-561 Sep 2012
In the typical human visual system, the macula allows for high visual resolution. Damage to this area from diseases, such as age-related macular degeneration (AMD), causes the loss of central vision in the form of a central scotoma. Since no treatment is available to reverse AMD, providing low vision rehabilitation to compensate for the loss of central vision is invaluable for individuals with this condition. Teaching persons with a central scotoma the technique of eccentric viewing to use their remaining peripheral retina to read and perform tasks of daily living has been shown to be effective. A number of methods and apparatuses are available to chart the visual field, but the preferred method is by microperimetry with such devices as the Macular Integrity Assessment Microperimeter or the Nidek MP-1 Micro Perimeter. Alternately, the visual field can be mapped by tangent screen perimetry, such as the Bjerrum tangent screen. Microperimetry allows clinicians to precisely delineate the borders of the scotoma and the corresponding visible pathology on the retina. The technique is also capable of displaying direct, real-time observation of the retina, and stimuli can be placed on the retina for the purposes of training in eccentric viewing. The Eccentric Viewing Resources Kit (EV Kit) was developed to address the issue of portability and ease of use in determining the trained retinal locus (TRL). The test consists of three screening cards that help identify the retinal locus closest to the fovea that the low vision practitioner can use for teaching eccentric viewing. The test has been reported to be useful in determining the TRL, and individuals who received training in eccentric viewing after the TRL was identified using this kit made significant improvements in their near vision, reading speed, reading comprehension, and performance of activities of daily living. This study shows a high degree of reliability between using the tools from the EV Kit to identify a TRL and mapping the central scotoma with a Bjerrum tangent screen. A definite advantage of both the smiley face card and the girl's face card is that they are portable, easily administered by a low vision practitioner, and easy for a person to understand. Nevertheless, there are disadvantages, which include the inability to identify a TRL in a diagonal location and a gross estimation of the best area on which to place the TRL. The kit identifies an approximate location in terms of superior, inferior, nasal, or temporal, but is less sensitive to locating the optimum degree for the TRL. Some persons require the TRL at a closer or further proximity to the fovea than what the EV Kit tools can identify. However, this tool, like the clock face method, is not meant to be used in isolation. (Contains 2 figures and 2 tables.)
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: Australia