A binocular approach to treating amblyopia: antisuppression therapy.
ABSTRACT We developed a binocular treatment for amblyopia based on antisuppression therapy.
A novel procedure is outlined for measuring the extent to which the fixing eye suppresses the fellow amblyopic eye. We hypothesize that suppression renders a structurally binocular system, functionally monocular.
We demonstrate using three strabismic amblyopes that information can be combined normally between their eyes under viewing conditions where suppression is reduced. Also, we show that prolonged periods of viewing (under the artificial conditions of stimuli of different contrast in each eye) during which information from the two eyes is combined leads to a strengthening of binocular vision in such cases and eventual combination of binocular information under natural viewing conditions (stimuli of the same contrast in each eye). Concomitant improvement in monocular acuity of the amblyopic eye occurs with this reduction in suppression and strengthening of binocular fusion. Furthermore, in each of the three cases, stereoscopic function is established.
This provides the basis for a new treatment of amblyopia, one that is purely binocular and aimed at reducing suppression as a first step.
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ABSTRACT: Strabismus is a frequent ocular disorder that develops early in life in humans. As a general rule, it is characterized by a misalignment of the visual axes which most often appears during the critical period of visual development. However other characteristics of strabismus may vary greatly among subjects, for example, being convergent or divergent, horizontal or vertical, with variable angles of deviation. Binocular vision may also vary greatly. Our main goal here is to develop the idea that such "polymorphy" reflects a wide variety in the possible origins of strabismus. We propose that strabismus must be considered as possibly resulting from abnormal genetic and/or acquired factors, anatomical and/or functional abnormalities, in the sensory and/or the motor systems, both peripherally and/or in the brain itself. We shall particularly develop the possible "central" origins of strabismus. Indeed, we are convinced that it is time now to open this "black box" in order to move forward. All of this will be developed on the basis of both presently available data in literature (including most recent data) and our own experience. Both data in biology and medicine will be referred to. Our conclusions will hopefully help ophthalmologists to better understand strabismus and to develop new therapeutic strategies in the future. Presently, physicians eliminate or limit the negative effects of such pathology both on the development of the visual system and visual perception through the use of optical correction and, in some cases, extraocular muscle surgery. To better circumscribe the problem of the origins of strabismus, including at a cerebral level, may improve its management, in particular with respect to binocular vision, through innovating tools by treating the pathology at the source.Frontiers in Integrative Neuroscience 09/2014; 8:71.
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ABSTRACT: Aim: Increasingly, those who are considered 'stereo-blind' by clinical testing, report that a 3D effect is perceived when watching stereoscopic films at the cinema. We report here the findings of a pilot study investigating the perception of 3D of stereoscopic video clips and games consoles, in observers who have no measurable stereo-acuity. Methods: Seven subjects were assessed for stereo-acuity using standard clinical tests. They were then asked to perform an object depth ordering task on an autostereoscopic screen (Nintendo 3DS) and a 3D video rating task, to determine recognition of depth in entertainment media. Results: No subject had measurable stereo-acuity or simultaneous perception. Only 2 subjects achieved 41% and 55% correct depth identification on the 3DS task; the other 5 subjects performed poorly. When viewing stereoscopic 3D video clips, even subjects who demonstrate zero ability to identify depth on the 3DS task rated the 'pop-out' 3D effect very highly, giving a median (interquartile range) score of 8 (5) out of 10. Comparatively, 2D control videos were given a rating of 3 (8) out of 10. Conclusion: Subjects with no clinically measurable stereo-acuity report compelling 'pop-out' depth effects when viewing 3D stereoscopic video. There are many mechanisms for determining depth from a scene, with the presence of motion potentially allowing the appreciation of stereoscopic depth. The nature of the technological method of stereoscopic 3D delivery may also aid recognition of, or give other significant cues to, depth through artefacts or presentation method.British and Irish Orthoptic Journal. 01/2014; 11.
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ABSTRACT: Occlusion therapy for amblyopia is predicated on the idea that amblyopia is primarily a disorder of monocular vision; however, there is growing evidence that patients with amblyopia have a structurally intact binocular visual system that is rendered functionally monocular due to suppression. Furthermore, we have found that a dichoptic treatment intervention designed to directly target suppression can result in clinically significant improvement in both binocular and monocular visual function in adult patients with amblyopia. The fact that monocular improvement occurs in the absence of any fellow eye occlusion suggests that amblyopia is, in part, due to chronic suppression. Previously the treatment has been administered as a psychophysical task and more recently as a video game that can be played on video goggles or an iPod device equipped with a lenticular screen. The aim of this case-series study of 14 amblyopes (six strabismics, six anisometropes and two mixed) ages 13 to 50 years was to investigate: 1. whether the portable video game treatment is suitable for at-home use and 2. whether an anaglyphic version of the iPod-based video game, which is more convenient for at-home use, has comparable effects to the lenticular version.Clinical and Experimental Optometry 08/2014; · 1.26 Impact Factor