Infant astigmatism and meridional amblyopia

Gwiazda, Jane; Mohindra, Indra; Brill, Sarah; Held, Richard

doi:10.1016/0042-6989(85)90042-2

Cited by 37 publications

(18 citation statements)

References 16 publications

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“…Our failure to find evidence of MA in infants and toddlers is in agreement with the results of previous studies of astigmats in this age group 13-16. One explanation for the failure to find MA in infants and toddlers is that MA does not develop at these young ages.…”

Section: Discussionsupporting

confidence: 92%

“…Teller et al16 found no significant difference in V versus H best-corrected acuity in a six-month-old astigmatic infant, and Held15 and Gwiazda et al13,14 reported that astigmatic infants did not show a preference for V or H gratings when wearing their best correction. However, these studies did not examine best-corrected acuity in comparison to a non-astigmatic control group, with the exception of one astigmatic infant for whom best-corrected acuity did not differ from non-astigmatic norms when tested between nine and twelve months of age 14…”

mentioning

confidence: 97%

“…Research to date suggests that the age range for the period of susceptibility to the effects of uncorrected astigmatism on visual development begins after the first year of life 13-16. Teller et al16 found no significant difference in V versus H best-corrected acuity in a six-month-old astigmatic infant, and Held15 and Gwiazda et al13,14 reported that astigmatic infants did not show a preference for V or H gratings when wearing their best correction.…”

mentioning

confidence: 99%

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Amblyopia in Astigmatic Infants and Toddlers

Dobson¹,

Harvey²,

Clifford-Donaldson

et al. 2010

Optometry and Vision Science

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Purpose To determine if reduced astigmatism-corrected acuity for vertical (V) and/or horizontal (H) gratings and/or meridional amblyopia (MA) are present prior to age three years in children who have with-the-rule astigmatism. Methods Subjects were 448 children, 6 months through 2 years of age with no known ocular abnormalities other than with-the-rule astigmatism, who were recruited through Women, Infants and Children clinics on the Tohono O’odham reservation. Children were classified as non-astigmats (≤ 2.00 D) or astigmats (> 2.00 D) based on right eye (RE) non-cycloplegic autorefraction measurements (Welch Allyn SureSight). RE astigmatism-corrected grating acuity for V and H stimuli was measured using the Teller Acuity Card procedure while children wore cross-cylinder lenses to correct their astigmatism or plano lenses if they had no astigmatism. Results Astigmatism-corrected acuity for both V and H gratings was significantly poorer in the astigmats than in the non-astigmats, and the reduction in acuity for astigmats was present for children in all three age groups examined (6 months to <1 year, 1 to <2 years, 2 to <3 years). There was no significant difference in V-H grating acuity (no evidence of MA) for the astigmatic group as a whole, or when data were analyzed for each age group. Conclusions Even in the youngest age group, astigmats tested with astigmatism correction showed reduced acuity for both V and H gratings, which suggests that astigmatism is having a negative influence on visual development. We found no evidence of orientation-related differences in astigmatism-corrected grating acuity, indicating either that MA does not develop prior to age 3 years, or that most of the astigmatic children had a type of astigmatism, i.e., hyperopic, that has proven to be less likely than myopic or mixed astigmatism to result in MA.

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Section: Discussionsupporting

confidence: 92%

mentioning

confidence: 97%

mentioning

confidence: 99%

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Amblyopia in Astigmatic Infants and Toddlers

Dobson¹,

Harvey²,

Clifford-Donaldson

et al. 2010

Optometry and Vision Science

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“…However, there is relatively little direct evidence documenting the sensitive period for development of these deficits, i.e., the period of time during infancy or childhood when the presence of uncorrected astigmatism leads to the development of astigmatism-related amblyopia. Two studies failed to find astigmatism-related MA for grating stimuli in myopic and hyperopic astigmatic infants less than one year of age, suggesting that MA does not develop prior to age one year 34,35. Given the grating acuity limits of infants, these results are consistent with studies of older astigmatic children and adults in which there was less prominent or no MA observed for mid to low spatial frequency stimuli 5,7,21,25.…”

Section: Sensitive Period For Development Of Astigmatism-related Amblmentioning

confidence: 99%

Development and Treatment of Astigmatism-Related Amblyopia

Harvey

2009

Optometry and Vision Science

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Blur induced by uncorrected astigmatism during early development can result in amblyopia, as evidenced by reduced best-corrected vision relative to normal, in measures of grating acuity, vernier acuity, contrast sensitivity across a range of spatial frequencies, recognition acuity, and stereoacuity. In addition, uncorrected astigmatism during early development can result in meridional amblyopia (MA), or best-corrected visual deficits that are greater for, or are present only for, specific stimulus orientations. Astigmatism-related amblyopia can be successfully treated with optical correction in children as old as school age, but the amblyopia may not be completely eliminated with optical treatment alone, and the age at which optical treatment is most effective has yet to be determined. Future research on determining the period of susceptibility of the visual system to negative effects of uncorrected astigmatism and exploration of alternative or complimentary treatment methods, in addition to optical correction, are warranted.

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“…It is argued that uncorrected astigmatism and horizontal nystagmus can affect acuity for gratings of different orientations differentially. [16][17][18] To circumvent this limitation, we have used concentric gratings. Cortical neurons respond best to edges (light-dark boundaries) with selective orientation, 19 of which only one is stimulated by linear gratings, and in many higher-order cortical neurons, considered to be functionally altered in amblyopia, receptive fields are organized concentrically, and they respond better to circular-shaped gratings.…”

Section: Introductionmentioning

confidence: 99%