alexa Role of the Completion Phenomenon in the Evaluation of Amsler Grid Results


Journal of Clinical & Experimental Ophthalmology

Author(s): Achard OA, Safran AB, Duret FC, Ragama E

Abstract Share this page

Purpose To evaluate the limitations, particularly those related to the perceptual completion phenomenon, of Amsler grid tests in patients with central scotomas caused by macular disorders. Methods We tested 15 affected eyes of 15 patients with macular lesions. In each subject, the central visual field was assessed by using four different types of Amsler grid testing and a tangent screen. Tests were conducted in a random order, and the sequence of tests was repeated once. The distance between the fixation point and the closest border of the plotted scotoma was assessed. For each patient, reproducibility in repeated examinations was evaluated by assessing changes in location of the computed center of the defects and by measuring changes in the position of the center of the scotoma. Results The tangent screen was more sensitive than Amsler grids in delineating the borders of the scotoma, and the results were more reproducible. Furthermore, by using a tangent screen, the fixation point was found adjacent to the scotoma. Conclusion Poor sensitivity and intraindividual variations found with Amsler grid testing are at least partly a result of the perceptual completion phenomenon. This phenomenon proved to be a dynamic and fluctuating process, as the results of two successive Amsler grid tests were not comparable, even when the technique was identical and the time between tests was no more than two to 15 minutes.

This article was published in American Journal of Ophthalmology and referenced in Journal of Clinical & Experimental Ophthalmology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version