Low frequency temporal modulation of light promotes a myopic shift in refractive compensation to all spectacle lenses

Crewther, Sheila G.; Barutchu, Ayla; Murphy, Melanie; Crewther, David P.

doi:10.1016/j.exer.2005.12.016

Cited by 39 publications

(57 citation statements)

References 22 publications

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“…In contrast to previous studies [3][4][5] , we detected a myopia shift after 2, 4 and 6 weeks' of 2-Hz FL stimulation. The refractive error after 6 weeks was approximately -5 D more myopic than before treatment (p !…”

Section: Discussioncontrasting

confidence: 55%

“…They found strobe-reared cats were significantly more myopic than normal cats. Crewther et al [5] reported that luminance modulation had no effect on refraction or ocular parameters in no-lens conditions; they considered that they were due to peripheral occlusion, which combines with the effects of temporal profile.…”

Section: Introductionmentioning

confidence: 99%

“…There is increasing evidence that disruption in light parameters, including intensity, diurnal lighting rhythms and spatiotemporal luminance modulation, can affect ocular development of refraction and axial growth [1][2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

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Effects of Flickering Light on Refraction and Changes in Eye Axial Length of C57BL/6 Mice

Chen²,

Tuo³

et al. 2011

Ophthalmic Res

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Aims: To investigate the effectiveness and feasibility of inducing myopia in mice by flickering-light (FL) stimulation. Methods: Forty-five 28-day-old C57BL/6 (B6) mice were randomly assigned to three groups: control group, FL stimulation group and form deprivation (FD) group. Mice in the control group were raised under 250 lux illumination from 8:00 a.m. to 8:00 p.m. Mice in the FL group were raised under illumination with a duty cycle of 50% at a flash rate of 2 Hz from 8:00 a.m. to 8:00 p.m. for 6 weeks. Mice in the FD group were raised under the same conditions as the control group; the right eyes of the mice were covered with semitransparent hemispherical plastic shells serving as eye diffusers. The refractive state and axial length (AL) of the right eyes were measured by eccentric infrared photorefraction and A-scan ultrasonography, respectively, before treatment and after 2, 4, 6 or 8 weeks’ treatment. Results: After 6 weeks’ exposure to FL, the refraction became more myopic compared with the control group as indicated by longer AL compared with the control group (p < 0.05); the FD eyes were more myopic than the FL eyes (p < 0.05). However, some mice lost their eye diffusers, and lens opacities were found. Conclusion: Myopia can be induced by FL in B6 mice. The myopic shift induced by FL is less than that induced by FD, but FL causes fewer side effects, and is safery and easier to manipulate.

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Section: Discussioncontrasting

confidence: 55%

Section: Introductionmentioning

confidence: 99%

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Effects of Flickering Light on Refraction and Changes in Eye Axial Length of C57BL/6 Mice

Chen²,

Tuo³

et al. 2011

Ophthalmic Res

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“…However, Cremieux, Orban, Duysens, Amblard, and Kennedy (1989) and Yu, Chen, Tuo, and Zhu (2011) found a myopic shift at lower rates of temporal modulation (2 Hz) in cats and C57BL/6 (B6) mice, respectively. On the other hand, Crewther, Barutchu, Murphy, and Crewther (2006) found that a ramped waveform flickering at 2 Hz had no effect on non-lens wearing chick eyes. The difference in waveforms, frequencies, and photoperiods make comparison of the results difficult, but one thing is clear-the temporal properties of the stimulus affect the refraction, and further study is required to clarify the temporal effects of flicker on emmetropization.…”

Section: Discussionmentioning

confidence: 94%

Chicks use changes in luminance and chromatic contrast as indicators of the sign of defocus

Rucker

Wallman

2012

Journal of Vision

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As the eye changes focus, the resulting changes in cone contrast are associated with changes in color and luminance. Color fluctuations should simulate the eye being hyperopic and make the eye grow in the myopic direction, while luminance fluctuations should simulate myopia and make the eye grow in the hyperopic direction. Chicks without lenses were exposed daily (9 a.m. to 5 p.m.) for three days on two consecutive weeks to 2 Hz sinusoidally modulated illumination (mean illuminance of 680 lux) to one of the following: in-phase modulated luminance flicker (LUM), counterphase-modulated red/green (R/G Color) or blue/yellow flicker (B/Y Color), combined color and luminance flicker (Color + LUM), reduced amplitude luminance flicker (Low LUM), or no flicker. After the three-day exposure to flicker, chicks were kept in a brooder under normal diurnal lighting for four days. Changes in the ocular components were measured with ultrasound and with a Hartinger Coincidence Refractometer (aus Jena, Jena, East Germany. After the first three-day exposure, luminance flicker produced more hyperopic refractions (LUM: 2.27 D) than did color flicker (R/G Color: 0.09 D; B/Y Color: -0.25 D). Changes in refraction were mainly due to changes in eye length, with color flicker producing much greater changes in eye length than luminance flicker (R/G Color: 102 μm; B/Y Color: 98 μm; LUM: 66 μm). Our results support the hypothesis that the eye can differentiate between hyperopic and myopic defocus on the basis of the effects of change in luminance or color contrast.

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“…More and more research into genetic factors of myopia give rise to its importance, with improved understanding of its biological mechanism (2,(13)(14)(15)(16)(17)(18). The association study of candidate genes and loci has been evaluated and the available evidence suggests the involvement of certain genes and loci in myopia in different ethnic populations (19)(20)(21)(22)(23)(24)(25)(26).…”

Section: Introductionmentioning

confidence: 99%

High myopia is not associated with single nucleotide polymorphisms in the COL2A1 gene in the Chinese population

Wang

Gao

et al. 2011

Mol Med Report

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Abstract. Association studies have revealed that the rs1635529 polymorphism in the COL2A1 (collagen, type Ⅱ, α 1) gene may be a potential candidate for myopia development and may be associated with myopia in Caucasians. The aim of this study was to investigate the association of high myopia with 5 polymorphisms including rs1635529 in COL2A1 in a Chinese population. Genomic DNA samples were selected from our Genomic DNA Repository for Myopia. A total of 581 high myopia individuals (refraction ≤-6.00D, spherical equivalent) and 384 normal controls (refraction between -0.50D and +2.00D, spherical equivalent) from a Han Chinese cohort participated in the association study. Allelic discrimination assay was performed on five single nucleotide polymorphisms (SNPs) (rs1635529, rs60542319, rs1635530, rs1635531 and rs954326) in COL2A1 by direct sequence analysis of polymerase chain reaction products. The genotype, allele and haplotype frequencies of the SNPs between cases and controls were compared by Chi-square test for association analysis. Based on the results, SNPs at rs1635530 and rs1635531 were found to be monomorphic in all subjects. There was no statistically significant difference in genotype, allele and haplotype frequencies for the other three SNPs (rs1635529, rs60542319 and rs954326) between the high myopia group and the control group. We do not find evidence to support an association of SNP rs1635529 in COL2A1 with high myopia in the Chinese population studied, nor of the other two SNPs (rs60542319 and rs954326).

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Low frequency temporal modulation of light promotes a myopic shift in refractive compensation to all spectacle lenses

Cited by 39 publications

References 22 publications

Effects of Flickering Light on Refraction and Changes in Eye Axial Length of C57BL/6 Mice

Effects of Flickering Light on Refraction and Changes in Eye Axial Length of C57BL/6 Mice

Chicks use changes in luminance and chromatic contrast as indicators of the sign of defocus

High myopia is not associated with single nucleotide polymorphisms in the COL2A1 gene in the Chinese population

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