Cycloplegic and Noncycloplegic Refractions of Chinese Neonatal Infants

Chen, Jie; Xie, Anmu; Hou, Lei; Su, Yanfeng; Liu, Fan; Thorn, Frank

doi:10.1167/iovs.10-5441

Cited by 35 publications

(31 citation statements)

References 20 publications

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“…Overall, this comparison suggests that refractive development in Chinese children over this age range is very similar to that seen in children of European origin, with little myopia detected until children reach the age of 5–6, provided that cycloplegia is adequate. Other results suggest that neonatal refractive development in Chinese children may also be similar to that in children of European origin [29], [32]. After the age of 5–6, possibly due to the impact of high amounts of study and limited time outdoors [33]–[35], the prevalence of myopia increases markedly in some East Asian populations to produce the current myopia epidemic [36]–[38].…”

Section: Discussionmentioning

confidence: 93%

“…We have not studied children under the age of 3, and there are few studies on such children of Chinese origin. However, Thorn and colleagues [29] have examined Chinese neonates, finding that the mean SE was +3.55 D, while the mean SE without cycloplegia was +0.58 D. The major difference between cycloplegic and non-cycloplegic refraction illustrates the importance of adequate cycloplegia in young children. The results of Thorn and colleagues suggest that Chinese neonates are highly hyperopic, as are neonates of European origin [30], [31].…”

Section: Discussionmentioning

confidence: 99%

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Refractive Errors in 3–6 Year-Old Chinese Children: A Very Low Prevalence of Myopia?

et al. 2013

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PurposeTo examine the prevalence of refractive errors in children aged 3–6 years in China.MethodsChildren were recruited for a trial of a home-based amblyopia screening kit in Guangzhou preschools, during which cycloplegic refractions were measured in both eyes of 2480 children. Cycloplegic refraction (from 3 to 4 drops of 1% cyclopentolate to ensure abolition of the light reflex) was measured by both autorefraction and retinoscopy. Refractive errors were defined as followed: myopia (at least −0.50 D in the worse eye), hyperopia (at least +2.00 D in the worse eye) and astigmatism (at least 1.50 D in the worse eye). Different definitions, as specified in the text, were also used to facilitate comparison with other studies.ResultsThe mean spherical equivalent refractive error was at least +1.22 D for all ages and both genders. The prevalence of myopia for any definition at any age was at most 2.5%, and lower in most cases. In contrast, the prevalence of hyperopia was generally over 20%, and declined slightly with age. The prevalence of astigmatism was between 6% and 11%. There was very little change in refractive error with age over this age range.ConclusionsPrevious reports of less hyperopic mean spherical equivalent refractive error, and more myopia and less hyperopia in children of this age may be due to problems with achieving adequate cycloplegia in children with dark irises. Using up to 4 drops of 1% cyclopentolate may be necessary to accurately measure refractive error in paediatric studies of such children. Our results suggest that children from all ethnic groups may follow a similar pattern of early refractive development, with little myopia and a hyperopic mean spherical equivalent over +1.00 D up to the age of 5–6 yearsin most conditions.

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Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Refractive Errors in 3–6 Year-Old Chinese Children: A Very Low Prevalence of Myopia?

et al. 2013

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“…[11, 12] There are also some data suggesting that differences in cycloplegic and non-cycloplegic refraction can occur in older age ranges thus affecting the population prevalence estimates of different refractive errors. [13] Our study confirmed the findings from previous studies.…”

Section: Discussionmentioning

confidence: 99%

Pre- and Postcycloplegic Refractions in Children and Adolescents

et al. 2016

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PurposeTo determine the difference between cycloplegic and non-cycloplegic refractive error and its associated factors in Chinese children and adolescents with a high prevalence of myopia.MethodsA school-based study including 1565 students aged 6 to 21 years was conducted in 2013 in Ejina, Inner Mongolia, China. Comprehensive eye examinations were performed. Pre-and postcycloplegic refractive error were measured using an auto-refractor. For cycloplegic refraction, one drop of topical 1.0% cyclopentolate was administered to each eye twice with a 5-minute interval and a third drop was administered 15 minutes after the second drop if the pupil size was less than 6 mm or if the pupillary light reflex was still present.ResultsTwo drops of cyclopentolate were found to be sufficient in 59% of the study participants while the other 41% need an additional drop. The prevalence of myopia was 89.5% in participants aged over 12 years and 68.6% in those aged 12 years or younger (P<0.001). When myopia was defined as spherical equivalent (SE) of less than -0.5 diopter (D), the prevalence estimates were 76.7% (95% confidence interval [CI] 74.6–78.8) and 54.1% (95%CI 51.6–56.6) before and after cycloplegic refraction, respectively. When hyperopia was defined as SE of more than 0.5D, the prevalence was only 2.8% (95%CI 1.9–3.6) before cycloplegic refraction while it was 15.5% (95%CI 13.7–17.3) after cycloplegic refraction. Increased difference between cycloplegic and non-cycloplegic refractive error was associated with decreased intraocular pressures (P = 0.01).ConclusionsLack of cycloplegia in refractive error measurement was associated with significant misclassifications in both myopia and hyperopia among Chinese children and adolescents. Decreased intraocular pressure was related to a greater difference between cycloplegic and non-cycloplegic refractive error.

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“…At birth, refractive state, measured with cycloplegia, is broadly distributed, ranging from low myopia (−1 to −4 D) to high hyperopia (up to 8 D) with a mean refraction of low (2 D) to moderate (3.5 D) hyperopia (Chen et al, 2011; Cook and Glasscock, 1951). This may reflect genetic factors that determine the location of the focal plane (corneal and lens curvatures and spacing) and the axial length before there is guidance from the emmetropization mechanism (Siegwart, Jr. and Norton, 2011).…”

Section: Human Studiesmentioning

confidence: 99%

Light levels, refractive development, and myopia – A speculative review

Norton

Siegwart

2013

Experimental Eye Research

171

152

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Recent epidemiological evidence in children indicates that time spent outdoors is protective against myopia. Studies in animal models (chick, macaque, tree shrew) have found that light levels (similar to being in the shade outdoors) that are mildly elevated compared to indoor levels, slow form-deprivation myopia and (in chick and tree shrew) lens-induced myopia. Normal chicks raised in low light levels (50 lux) with a circadian light on/off cycle often develop spontaneous myopia. We propose a model in which the ambient illuminance levels produce a continuum of effects on normal refractive development and the response to myopiagenic stimuli such that low light levels favor myopia development and elevated levels are protective. Among possible mechanisms, elevation of retinal dopamine activity seems the most likely. Inputs from intrinsically-photosensitive retinal ganglion cells (ipRGCs) at elevated light levels may be involved, providing additional activation of retinal dopaminergic pathways.

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Cycloplegic and Noncycloplegic Refractions of Chinese Neonatal Infants

Cited by 35 publications

References 20 publications

Refractive Errors in 3–6 Year-Old Chinese Children: A Very Low Prevalence of Myopia?

Refractive Errors in 3–6 Year-Old Chinese Children: A Very Low Prevalence of Myopia?

Pre- and Postcycloplegic Refractions in Children and Adolescents

Light levels, refractive development, and myopia – A speculative review

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