Deficits of spatial localization in children with strabismic amblyopia

Fronius, Maria; Sireteanu, Ruxandra; Zubcov, Alina A.

doi:10.1007/s00417-004-0936-5

Cited by 26 publications

(35 citation statements)

References 41 publications

(44 reference statements)

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“…Along with extensive individual differences in the pattern of perceptual visual distortions between subjects, this phenomenon has also been identified in other studies. 10,15,[17][18][19]22,26,31 Perceptual visual distortions were found in this study to be more severe in participants with a strabismic component to their amblyopia than in those with pure anisometropia, as found in other studies. 11,14,15,21,26 However, there were only five anisometropic amblyopes to make comparisons against in our pilot study; therefore further investigation of this potential dichotomy in a larger group of amblyopes would be helpful.…”

Section: Discussion Exploration Of Global Distortion and Uncertainty supporting

confidence: 73%

“…The literature suggests a dichotomy in the nature of perceptual visual distortions between strabismic amblyopes and anisometropic amblyopes; anisometropic amblyopes, who usually have normal binocular function, 32 frequently have little or no distortion. 11,14,15,21,26 It would therefore be of clinical interest to investigate the relationship between severity of perceptual visual distortions and strength of binocular function in amblyopic individuals; if severe perceptual distortions could act as a barrier to good binocular vision, then improving them could potentially be a part of future amblyopia treatment approaches.…”

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confidence: 99%

“…6 Another visual processing deficit occurring among amblyopic individuals is perceptual visual distortions, first identified in the literature by Pugh,7,8 who described the abnormal spacing, fragmentation, and warping of Snellen letters experienced by her amblyopic patients. Perceptual visual distortions have been subsequently profiled in adults with both treated and untreated amblyopia [9][10][11][12][13][14][15][16][17][18][19][20][21] through use of a variety of measures, including dichoptic or monocular shape reconstructions, 14,15,[17][18][19][20][22][23][24][25] sketching suprathreshold gratings, 10,[19][20][21][22] hyperacuity/Vernier alignment, 9,[11][12][13][14][15][16]26,27 and matching portions of the visual space. 11,14,28 Studies using hyperacuity-type tasks have identified a correlation between amblyopic visual acuity deficits and severity of perceptual visual distortions, …”

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confidence: 99%

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Perceptual Visual Distortions in Adult Amblyopia and Their Relationship to Clinical Features

Piano

Bex

Simmers

2015

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. Develop a paradigm to map binocular perceptual visual distortions in adult amblyopes and visually normal controls, measure their stability over time, and determine the relationship between strength of binocular single vision and distortion magnitude.METHODS. Perceptual visual distortions were measured in 24 strabismic, anisometropic, or microtropic amblyopes (interocular acuity difference ‡ 0.200 logMAR or history of amblyopia treatment) and 10 controls (mean age 27.13 6 10.20 years). The task was mouse-based target alignment on a stereoscopic liquid crystal display monitor, measured binocularly five times during viewing dichoptically through active shutter glasses, amblyopic eye viewing crosshairs, fellow eye viewing single target dots (16 locations within central 58), and five times nondichoptically, with all stimuli visible to either eye. Measurements were repeated over time (1 week, 1 month) in eight amblyopic subjects, evaluating test-retest reliability. Measurements were also correlated against logMAR visual acuity, horizontal prism motor fusion range, Frisby/Preschool Randot stereoacuity, and heterophoria/heterotropia prism cover test measurement.RESULTS. Sixty-seven percent (16/24) of amblyopes had significant perceptual visual distortions under dichoptic viewing conditions compared to nondichoptic viewing conditions and dichoptic control group performance. Distortions correlated with the strength of motor fusion (r ¼ À0.417, P ¼ 0.043) and log stereoacuity (r ¼ 0.492, P ¼ 0.015), as well as near angle of heterotropic/heterophoric deviation (r ¼ 0.740, P < 0.001), and, marginally, amblyopia depth (r ¼ 0.405, P ¼ 0.049). Global distortion index (GDI, mean displacement) remained, overall, consistent over time (median change in GDI between baseline and 1 week ¼ À0.038, 1 month ¼ À0.088; x-axis Z ¼ 4.4256, P < 0.001; y-axis Z ¼ 5.0547, P < 0.001).CONCLUSIONS. Perceptual visual distortions are stable over time and associated with poorer binocular function, greater amblyopia depth, and larger angles of ocular deviation. Assessment of distortions may be relevant for recent perceptual learning paradigms specifically targeting binocular vision.

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Section: Discussion Exploration Of Global Distortion and Uncertainty supporting

confidence: 73%

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confidence: 99%

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confidence: 99%

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Perceptual Visual Distortions in Adult Amblyopia and Their Relationship to Clinical Features

Piano

Bex

Simmers

2015

Invest. Ophthalmol. Vis. Sci.

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“…There is controversy about the spatial localization of the dominant eyes of amblyopes: while some studies claimed that it was better than in normal visual system, others reported impaired function (22)(23)(24)(25)(26). Our research shows that good eye controls the superiority on visual information acceptation, since a number of cortical areas have reduced levels of activation in amblyopia.…”

Section: Discussionmentioning

confidence: 47%

Bold‐fMRI activation from visual stimuli in human amblyopia with independent component analysis

Zeng

Jiang

2010

Concepts Magn Reson

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Amblyopia is common human visual disease. In this article, we use blood oxygenation level dependent functional magnetic resonance imaging to study child amblyopica with independent component analysis method. Comparing the results of amblyopic eye viewing with that of normal eye viewing, we find that, on the one hand, human amblyopia may lead to occipital cortex dysfunction and reduce the activity of primary visual areas; on the other hand, it may extend visual stimuli into other stimuli reflection.

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“…Amblyopia is the developmental impaired vision (of no organic cause) typified by reduced visual acuity, distorted space perception and incorrect localization of objects in space (Bedell et al, 1985;Skottun et al, 1986;Fronius et al, 2004). It may be a consequence of long term binocular suppression that remains under monocular conditions -although some advocate that it may precede the strabismus (Schor, 1978).…”

Section: Nih Public Accessmentioning

confidence: 99%

Monocular fixation with the optic nerve head: a case report

Vera-Díaz

Peli

2008

Ophthalmic Physiologic Optic

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Purpose-To document and discuss the case of a patient with left esotropia (ET) who uses the left eye optic nerve head (ONH) for monocular "fixation".Case Report-The patient was an 80 year-old male with left ET from early childhood. Retinal tracking monocular fixation measurements with a Nidek MP-1 revealed stable fixation within the left ONH area. In an attempt to challenge the initial observation, further assessments of fixation were performed with a smaller target size and requiring various gaze positions. MP-1 fixation data showed remarkably stable monocular fixation (±1deg over 30 sec) mostly within the left ONH for all the target sizes and positions of gaze tested. Additional clinical binocular evaluations showed concomitant left ET~28Δ, no movement with cover test regardless of fixation target, and no significant monocular motility restrictions. Visuoscopy also revealed fixation at the left ONH. There was a strong family history of ET, but none of the other affected descendants tested (n=3) demonstrated the same behaviour.Conclusions-This is the first report documenting abnormally developed monocular ocular motor system with principal visual direction and zero retinomotor value shifted from the fovea to the ONH. We do not believe that there is any direct visual input from the ONH. The patient may use visual information obtained by glancing with peripapillary areas to determine the target position (though this was largely ruled out), or obtain position information from the average luminance produced by scattered light around the ONH margin. The abnormal oculocentric direction might then be combined with extra retinal information (efferent copy or extraocular muscle proprioception) of the eye location in the orbit to stabilize the fixation. This patient does not have the Blind Spot Syndrome as previously described (Swan, 1948). Possible aetiologies are discussed. We propose the use of a retinal perimeter for documentation of eccentric fixation in strabismus. KeywordsBlind Spot; Optic Nerve Head; Eccentric Fixation; Principal Visual Direction; Retinomotor Value; Esotropia; Retinal PerimeterIn early acquired strabismus the visual system typically develops sensory adaptations to avoid the symptoms of diplopia and visual confusion (Pickwell, 1984), often reported as "double vision". If these adaptations did not develop, the patient would experience diplopia, as the image of an object seen with the fovea of the nondeviated eye would also be seen with a peripheral retinal area of the deviated eye (retinal images would not fall on corresponding points); and visual confusion, as the fovea of the deviated eye would receive an image different to that falling on the fovea of the non-deviated eye (two corresponding points would receive different images which would appear superimposed, in the same direction). These phenomena are usually reported, when they occur in central retina, by patients who develop strabismus as adults (at an age when they typically do not develop adaptations). While diplopia and visual con...

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Deficits of spatial localization in children with strabismic amblyopia

Abstract: Children with strabismic amblyopia exhibited localization deficits and relationship to clinical data similar to those in adult amblyopes. These data are important for further investigations about the substrate, plasticity and the clinical relevance of perceptual distortions.

Cited by 26 publications

References 41 publications

Perceptual Visual Distortions in Adult Amblyopia and Their Relationship to Clinical Features

Perceptual Visual Distortions in Adult Amblyopia and Their Relationship to Clinical Features

Bold‐fMRI activation from visual stimuli in human amblyopia with independent component analysis

Monocular fixation with the optic nerve head: a case report

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