Anisometropic Amblyopia: Spatial Contrast Sensitivity Deficits in Inferred Magnocellular and Parvocellular Vision

Zele, Andrew J.; Pokorny, Joel; Lee, David Y.; Ireland, Demelza J.

doi:10.1167/iovs.06-1207

Cited by 35 publications

(36 citation statements)

References 56 publications

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“…Moreover, Maebera et al 8 reported that contrast sensitivity was reduced in amblyopic eyes, while normal eyes were generally normal. Similar to Zele et al 20 , in the present study we detected no significant differences in CSF throughout the spatial frequency range when the normal eyes of microtropic and anisometropic patients were compared with age-matched nomograms.…”

Section: Discussionsupporting

confidence: 92%

“…Chatzistefanou et al 9 also found that the normal eyes of amblyopic patients had abnormal CSF, regardless of whether they had undergone occlusion therapy. In contrast, Zele et al 20 found that the normal eyes of amblyopes had normal values at all spatial frequencies. Moreover, Maebera et al 8 reported that contrast sensitivity was reduced in amblyopic eyes, while normal eyes were generally normal.…”

Section: Discussionmentioning

confidence: 86%

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Contrast Sensitivity in Microtropic and Anisometropic Eyes of Successfully Treated Amblyopes

Öner

Bayar

Oto

et al. 2017

tjo

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Objectives:To assess and compare contrast sensitivity function in the previously amblyopic and non-amblyopic “normal” eyes of patients with microtropia and anisometropia who achieved 20/20 visual acuity after occlusion therapy.Materials and Methods:Contrast sensitivity was tested monocularly on both eyes of 34 successfully treated microtropic and 15 anisometropic subjects (visual acuity 20/20 in both eyes). Contrast sensitivity function was evaluated by CSV-1000E and age-matched nomograms were used (spatial frequencies of 3, 6, 12, and 18 cycles per degree [cpd]) for comparison.Results:The mean age of subjects was 11.2±1.3 years in the microtropic group, 9.8±1.7 years in the anisometropic group (7-12 years); the mean follow-up time was 16.4±3.2 months (12 to 92) in the microtropic group and 27.7±1.8 months (12-84) in the anisometropic group. Statistical comparison of the microtropic amblyopic eyes versus non-microtropic eyes showed significant differences at spatial frequencies of 3, 12 and 18 cpd (3 cpd, t=2.8, p=0.007; 6 cpd, t=1.1 p=0.261; 12 cpd, t=2.2, p=0.033; 18 cpd, t=2.2, p=0.030). When anisometropic eyes were compared with non-anisometropic eyes, there was a significant difference only at 12 cpd (t=2.1 p=0.049). The comparison of non-amblyopic eyes versus age-matched nomograms revealed no differences at any of the spatial frequencies (p>0.05 for all).Conclusion:Contrast sensitivity was decreased in patients with amblyopia, especially in the microtropic group. The assessment of contrast sensitivity function may serve as a new parameter for termination of occlusion therapy.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 86%

Contrast Sensitivity in Microtropic and Anisometropic Eyes of Successfully Treated Amblyopes

Öner

Bayar

Oto

et al. 2017

tjo

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“…In humans, the bulk of the data reports greater deficits in aspects of vision thought to be mediated by the P pathway (deficits for high spatial frequency stimuli: Bradley & Freeman, 1981; Hess & Howell, 1977; Levi & Harwerth, 1977, deficits for red/green chromatic stimuli: Davis, Sloper, Neveu, Hogg, Morgan, & Holder, 2006; Demirci, Gezer, Sezen, Ovali, Demiralp, & Isoglu-Alkoc, 2002; but see Zele, Pokorny, Lee, & Ireland, 2007). Corroborating the human results, studies of visually deprived animals have reported that morphological changes are greater within the P layers, compared to the M layers, of the LGN (Hendrickson et al, 1987; LeVay, Wiesel, & Hubel, 1980 and see von Noorden, Crawford, & Levacy, 1983 for greater P disruption in the LGN of a single human).…”

Section: Discussionmentioning

confidence: 99%

Chromatic and luminance contrast sensitivity in fullterm and preterm infants

Bosworth¹,

Dobkins²

2009

Journal of Vision

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In order to investigate the contributions of visual experience vs. preprogrammed mechanisms on visual development, the current study compared contrast sensitivity in preterm vs. fullterm infants. If development is tied to time since conception, preterm infants should match the developmental trajectories of fullterm infants when plotted in postterm age. By contrast, if development is influenced by visual experience, preterm and fullterm infants should match when plotted in postnatal age. Luminance (light/dark) and chromatic (red/green) contrast sensitivities (CS) were measured in 25 preterm (born, on average, 6.6 weeks early) and 77 fullterm infants, between 1 and 6 months postterm. In the first few months, luminance CS was found to be predicted by postterm age, suggesting that preprogrammed development is sufficient to account for luminance CS. By contrast, chromatic CS exceeded that predicted by postterm age, which suggests that time since birth confers a benefit on chromatic CS. The preterms’ 6.6 weeks of additional time since birth is roughly equivalent to 3.7 weeks of development in chromatic CS. In sum, these results suggest that chromatic CS is more influenced by early postnatal visual experience than luminance CS, which may have implications for development of parvocellular and magnocellular pathways.

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“…During the test interval, a D6 pattern of positive contrast was presented in the center of a pedestal square that had a decremental luminance, with both stimuli presented simultaneously for 45 ms. For both paradigms, the D6 was presented with either a vertical or horizontal orientation, chosen randomly. An adapting field was presented continuously for both paradigms (Zele et al, 2007). by the MC pathway, at least at low frequencies.…”

Section: Spatial Contrast Sensitivitymentioning

confidence: 99%

Review: Steady and pulsed pedestals, the how and why of post-receptoral pathway separation

Pokorny

2011

Journal of Vision

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In the mid-1990s, the Pokorny and Smith research group began a series of psychophysical experiments with the aim of separately measuring magnocellular (MC)- and parvocellular (PC)-pathway mediated achromatic contrast discrimination. Three paradigms provide complementary information: The pulsed-pedestal paradigm reveals PC contrast gain, the steady-pedestal paradigm reveals steady-state MC-pathway sensitivity, and the pedestal-Δ-pedestal paradigm reveals MC contrast gain. Further studies investigated the temporal and spatial summation properties of the underlying mechanisms and extended the work to include measures of spatial resolution, chromatic contrast discrimination, the detection and identification of stimulus polarity, and the inferred retinal mechanisms mediating illusory distortions. Other laboratories have also applied the methods to the study of normal and clinically impaired vision. This review describes the pedestal methodologies, how they relate to physiology, and how they have been and should be employed.

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Anisometropic Amblyopia: Spatial Contrast Sensitivity Deficits in Inferred Magnocellular and Parvocellular Vision

Cited by 35 publications

References 56 publications

Contrast Sensitivity in Microtropic and Anisometropic Eyes of Successfully Treated Amblyopes

Contrast Sensitivity in Microtropic and Anisometropic Eyes of Successfully Treated Amblyopes

Chromatic and luminance contrast sensitivity in fullterm and preterm infants

Review: Steady and pulsed pedestals, the how and why of post-receptoral pathway separation

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