Orientation Tuning and Contrast Dependence of Continuous Flash Suppression in Amblyopia and Normal Vision.

Autor:	Gao TY; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand., Ledgeway T; School of Psychology, University of Nottingham, Nottingham, United Kingdom., Lie AL; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand., Anstice N; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand.; Discipline of Optometry and Vision Science, University of Canberra, Australian Capital Territory, Australia., Black J; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand., McGraw PV; School of Psychology, University of Nottingham, Nottingham, United Kingdom., Thompson B; School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand.; School of Optometry and Vision Science, University of Waterloo, Ontario, Canada.
Jazyk:	angličtina
Zdroj:	Investigative ophthalmology & visual science [Invest Ophthalmol Vis Sci] 2018 Nov 01; Vol. 59 (13), pp. 5462-5472.
DOI:	10.1167/iovs.18-23954
Abstrakt:	Purpose: Suppression in amblyopia may be an unequal form of normal interocular suppression or a distinct pathophysiology. To explore this issue, we examined the orientation tuning and contrast dependence of continuous flash suppression (CFS) in adults with amblyopia and visually normal controls. Methods: Nine patients (mean age, 26.9 ± SD 4.7 years) and 11 controls (mean age, 24.8 ± SD 5.3 years) participated. In the CFS paradigm, spatially one-dimensional noise refreshing at 10 Hz was displayed in one eye to induce suppression of the other eye, and suppression strength was measured by using a grating contrast increment detection task. In experiment 1, noise contrast was fixed and the orientation difference between the noise and the grating was varied. In experiment 2, noise and grating orientations were identical and noise contrast was varied. Results: Suppression patterns varied in both groups. In experiment 1, controls showed consistently orientation-tuned CFS (mean half-height bandwidth, 35.8° ± SD 21.5°) with near-equal strength between eyes. Five of nine patients with amblyopia exhibited orientation-independent CFS. Eight patients had markedly unequal suppression between eyes. Experiment 2 found that increasing the noise contrast to the amblyopic eye may produce suppression of the fellow eye, but suppression remained unequal between eyes. Conclusions: Our data revealed that orientation specificity in CFS was very broad or absent in some patients with amblyopia, which could not be predicted by clinical measures. Suppression was unbalanced across the entire contrast range for most patients. This suggests that abnormal early visual experience disrupts the development of interocular suppression mechanisms.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu