Patterns of spatial distortions in human amblyopia are invariant to stimulus duration and instruction modality

Sireteanu, Ruxandra; Thiel, Aylin; Fikus, Sandra; Iftime, Adrian

doi:10.1016/j.visres.2008.01.028

Cited by 15 publications

(14 citation statements)

References 32 publications

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“…This neurological anomaly in the visual pathway generates a wide range of visual deficits beyond the clinical acuity-based definition (for review see Levi and Carkeet, 1993) including, for example, reduced contrast sensitivity at high and medium spatial frequencies (Hess and Howell, 1977; Hess, 1979; Levi and Harwerth, 1977; Bradley and Freeman, 1981; Levi, 1988), reduced stereoacuity (Reinecke, 1979; McKee et al, 2003; O’Connor et al, 2010), impaired sensitivity to shape changes and abnormalities in contour processing (Hess et al, 1999; Kovacs et al, 2000; Chandna et al, 2001; Levi et al, 2007) plus abnormal patterns of lateral interaction (Bonneh, 2004; Polat et al, 2005). Amblyopes also exhibit poor performance on spatial localisation tasks (Bedell and Flom, 1981; Bedell and Flom, 1983; Levi et al, 1987; Fronius et al, 2004) such as vernier acuity tasks (Levi and Klein, 1982a, 1982b; Levi and Klein, 1983, 1985; Levi et al, 1985) and often exhibit dramatic misperception of gratings (Hess et al, 1978; Barrett et al, 2003) and other targets (Pugh, 1958; Lagreze and Sireteanu, 1991; Sireteanu et al, 2008). …”

Section: Definitionsmentioning

confidence: 99%

The relationship between anisometropia and amblyopia

Barrett

Bradley

Candy

2013

Progress in Retinal and Eye Research

139

121

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This review aims to disentangle cause and effect in the relationship between anisometropia and amblyopia. Specifically, we examine the literature for evidence to support different possible developmental sequences that could ultimately lead to the presentation of both conditions. The prevalence of anisometropia is around 20% for an inter-ocular difference of 0.5D or greater in spherical equivalent refraction, falling to 2-3%, for an inter-ocular difference of 3D or above. Anisometropia prevalence is relatively high in the weeks following birth, in the teenage years coinciding with the onset of myopia and, most notably, in older adults starting after the onset of presbyopia. It has about one-third the prevalence of bilateral refractive errors of the same magnitude. Importantly, the prevalence of anisometropia is higher in highly ametropic groups, suggesting that emmetropization failures underlying ametropia and anisometropia may be similar. Amblyopia is present in 1-3% of humans and around one-half to two-thirds of amblyopes have anisometropia either alone or in combination with strabismus. The frequent co-existence of amblyopia and anisometropia at a child’s first clinical examination promotes the belief that the anisometropia has caused the amblyopia, as has been demonstrated in animal models of the condition. In reviewing the human and monkey literature however it is clear that there are additional paths beyond this classic hypothesis to the co-occurrence of anisometropia and amblyopia. For example, after amblyopia secondary to either deprivation or strabismus has emerged, anisometropia often follows. In cases of anisometropia with no apparent deprivation or strabismus, questions remain about the failure of the emmetropization mechanism that routinely eliminates infantile anisometropia. Also, the chronology of amblyopia development is poorly documented in cases of ‘pure’ anisometropic amblyopia. Although indirect, the therapeutic impact of refractive correction on anisometropic amblyopia provides strong support for the hypothesis that the anisometropia caused the amblyopia. Direct evidence for the aetiology of anisometropic amblyopia will require longitudinal tracking of at-risk infants, which poses numerous methodological challenges. However, if we are to prevent this condition, we must understand the factors that cause it to develop.

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Section: Definitionsmentioning

confidence: 99%

The relationship between anisometropia and amblyopia

Barrett

Bradley

Candy

2013

Progress in Retinal and Eye Research

139

121

View full text Add to dashboard Cite

show abstract

“…46 Careful psychophysical studies have shown that the fellow eye has reduced optotype 4,47 and Vernier acuity, 48 and perhaps more importantly, greater spatial uncertainty and distortion affecting both foveal and extra-foveal vision. 9,10 Such deficits in spatial vision, affecting both the amblyopic and fellow eyes, may therefore contribute to the binocular visual localization deficit observed in the present study. Another possible contributing factor may be the temporal interval between the two stimuli whose positions were judged.…”

Section: Optimal Audiovisual Spatial Integration In Amblyopiamentioning

confidence: 69%

“…[4][5][6][7][8] The disorder also involves spatial distortions and positional uncertainty that affect vision in both the amblyopic eye and the fellow eye. [9][10][11][12][13] Emerging research suggests that perceptual abnormalities in amblyopia are not limited to vision, but also involve multisensory integration in the audiovisual realm. [14][15][16] Multisensory integration refers to the process of unifying overlapping information from different senses to form an accurate and coherent perception of the external world.…”

mentioning

confidence: 99%

Optimal Audiovisual Integration in the Ventriloquism Effect But Pervasive Deficits in Unisensory Spatial Localization in Amblyopia

Richards

Goltz

Wong

2018

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. Classically understood as a deficit in spatial vision, amblyopia is increasingly recognized to also impair audiovisual multisensory processing. Studies to date, however, have not determined whether the audiovisual abnormalities reflect a failure of multisensory integration, or an optimal strategy in the face of unisensory impairment. We use the ventriloquism effect and the maximum-likelihood estimation (MLE) model of optimal integration to investigate integration of audiovisual spatial information in amblyopia.METHODS. Participants with unilateral amblyopia (n ¼ 14; mean age 28.8 years; 7 anisometropic, 3 strabismic, 4 mixed mechanism) and visually normal controls (n ¼ 16, mean age 29.2 years) localized brief unimodal auditory, unimodal visual, and bimodal (audiovisual) stimuli during binocular viewing using a location discrimination task. A subset of bimodal trials involved the ventriloquism effect, an illusion in which auditory and visual stimuli originating from different locations are perceived as originating from a single location. Localization precision and bias were determined by psychometric curve fitting, and the observed parameters were compared with predictions from the MLE model. RESULTS.Spatial localization precision was significantly reduced in the amblyopia group compared with the control group for unimodal visual, unimodal auditory, and bimodal stimuli. Analyses of localization precision and bias for bimodal stimuli showed no significant deviations from the MLE model in either the amblyopia group or the control group.CONCLUSIONS. Despite pervasive deficits in localization precision for visual, auditory, and audiovisual stimuli, audiovisual integration remains intact and optimal in unilateral amblyopia.

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“…This pattern of auditory localization deficits is remarkable because it does not match the spatial distribution of visual spatial or oculomotor deficits observed in amblyopia. 64,68,69 Although participants localized sounds using a visually guided cursor, the task was done with both eyes open, and the specified click locations were well within the field of view of the fellow eye even for the most eccentric auditory targets at 168 left and right of the midline. Furthermore, the accuracy of visual localization with both eyes open, as measured by saccade amplitude, is normal in adults with anisometropic amblyopia 64 and strabismic amblyopia.…”

Section: Discussionmentioning

confidence: 99%

Impaired Spatial Hearing in Amblyopia: Evidence for Calibration of Auditory Maps by Retinocollicular Input in Humans

Richards

Goltz

Wong

2019

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. Evidence from animals and blind humans suggests that early visual experience influences the developmental calibration of auditory localization. Hypothesizing that unilateral amblyopia may involve cross-modal deficits in spatial hearing, we measured the precision and accuracy of sound localization in humans with amblyopia. METHODS. All participants passed a standard hearing test. Experiment 1 measured sound localization precision for click stimuli in 10 adults with amblyopia and 10 controls using a minimum audible angle (MAA) task. Experiment 2 measured sound localization error (i.e., accuracy) for click train stimuli in 14 adults with amblyopia and 16 controls using an absolute sound localization task. RESULTS. In Experiment 1, the MAA (mean 6 SEM) was significantly greater in the amblyopia group compared with controls (2.75 6 0.308 vs. 1.69 6 0.098, P ¼ 0.006). In Experiment 2, the overall sound localization error was significantly greater in the amblyopia group compared with controls (P ¼ 0.047). The amblyopia group also showed significantly greater sound localization error in the auditory hemispace ipsilateral to the amblyopic eye (P ¼ 0.036). At a location within this auditory hemispace, the magnitude of sound localization error correlated significantly with deficits in stereo acuity (P ¼ 0.036). CONCLUSIONS. The precision and accuracy of sound localization are impaired in unilateral amblyopia. The asymmetric pattern of sound localization error suggests that amblyopic vision may interfere with the development of spatial hearing via the retinocollicular pathway.

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Patterns of spatial distortions in human amblyopia are invariant to stimulus duration and instruction modality

Cited by 15 publications

References 32 publications

The relationship between anisometropia and amblyopia

The relationship between anisometropia and amblyopia

Optimal Audiovisual Integration in the Ventriloquism Effect But Pervasive Deficits in Unisensory Spatial Localization in Amblyopia

Impaired Spatial Hearing in Amblyopia: Evidence for Calibration of Auditory Maps by Retinocollicular Input in Humans

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