The Flash-lag Effect in Amblyopia

Abstract

Purpose Amblyopes suffer a defect in temporal processing, presumably because of a neural delay in their visual processing. By measuring flash-lag effect (FLE), we investigate whether the amblyopic visual system could compensate for the intrinsic neural delay due to visual information transmissions from the retina to the cortex. Methods Eleven adults with amblyopia and 11 controls with normal vision participated in this study. We assessed the monocular FLE magnitude for each subject by using a typical FLE paradigm: a bar moved horizontally, while a flashed bar briefly appeared above or below it. Three luminance contrasts of the flashed bar were tested: 0.2, 0.6, and 1. Results All participants, controls and those with amblyopia, showed a typical FLE. However, the FLE magnitude of participants with amblyopia was significantly shorter than that of the control participants, for both their amblyopic eye (AE) and fellow eye (FE). A nonsignificant difference was found in FLE magnitude between the AE and the FE. Conclusions We demonstrate a reduced FLE both in the AE as well as the FE of patients with amblyopia, suggesting a global visual processing deficit. We suggest it may be attributed to a more limited spatiotemporal extent of facilitatory anticipatory activity within the amblyopic primary visual cortex.

Interocular Transfer: The Dichoptic Flash-Lag Effect in Controls and Amblyopes

“…Actually, by using the FLE and the FGE, we previously investigated how the amblyopic visual system implements motion extrapolation within the monocular visual processing stage. 23 , 24 In addition, we also found that patients with amblyopia exhibit a smaller FLE and a larger FGE both in their AE and FE. Such reduced FLE would characterize less anticipation of the position of the moving object along its trajectory.…”

“…4 A), suggesting impaired motion extrapolation in the amblyopic visual system, consistent with our previous studies using monocular viewing. 23 , 24 In addition, we found a shallower slope of the psychometric function in the AE compared with that in the NDE (see Fig. 4 B).…”

“…Such reduced FLE would characterize less anticipation of the position of the moving object along its trajectory. 23 Hence, these findings suggest that the amblyopic visual system suffers from impairments in motion extrapolation computations that could be done in V1. 20 , 21 …”

Methods of Amblyopia Treatment

“…Этот препарат обладает холинэргическими и нейропротекторными свойствами, участвует в метаболизме фосфолипидов, тем самым защищает структурную целостность клеточных мембран и предотвращает повреждение нервных клеток. В неврологии он применяется в период восстановления после нарушения мозгового кровообращения, в офтальмологии -при глаукоме [9]. У взрослых пациентов с амблиопией цитиколин применялся в комбинации с окклюзионной терапией, было отмечено улучшение остроты зрения, но эффект был нестойким и ограничивался периодом применения препарата.…”

Temporal synchronization elicits enhancement of binocular vision functions

“… 2 , 13 , 14 , 15 An important example of ocular imbalance is amblyopia, a developmental condition resulting from the abnormal development of the visual system in the early stages of life, 16 characterized by a unilateral decrease in various spatial resolution dysfunctions, 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 the presence of spatial crowding, 25 and reduced temporal functions. 24 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 Indeed, various studies have shown that binocular imbalance in the spatial or stimulus energy domain is associated with lower binocular summation, 13 , 15 , 38 , 39 , 40 which is restored by adjusting the contrast or stimulus energy of the two eyes. 39 , 41 …”