Nature of the refractive errors in rhesus monkeys (Macaca mulatta) with experimentally induced ametropias

Qiao-Grider, Ying; Hung, Li-Fang; Kee, Chea Su; Ramamirtham, Ramkumar; Smith, Earl L.

doi:10.1016/j.visres.2010.06.008

Cited by 19 publications

(24 citation statements)

References 111 publications

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“…A review paper on the role of the lens in refractive development concluded that “its participation is non-existent or minimal at best”. 29 This agrees with the finding of no association between refractive error and lens thickness in 210 rhesus monkeys, 30 although it should be noted that most of the monkeys were younger than the children tested in the current study even when age was adjusted for the difference between monkey and human years. Another caveat is that most of the experiments using animals lasted for relatively short periods of time and changes in the lens may take longer to appear.…”

Section: Discussionsupporting

confidence: 90%

Longitudinal Changes in Lens Thickness in Myopic Children Enrolled in the Correction of Myopia Evaluation Trial (COMET)

Gwiazda

Norton²,

Hou

et al. 2015

Current Eye Research

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Purpose To describe longitudinal changes in lens thickness in myopic children in the Correction of Myopia Evaluation Trial (COMET) and to investigate the association between these changes and myopia progression. Methods Four-hundred sixty-nine 6 to <12-year-old children with −1.25 to −4.50 D of myopia were enrolled in COMET, a clinical trial comparing single vision lenses (SVLs) versus progressive addition lenses (PALs) for slowing myopia. Children remained in their original lenses for 5 years and then could wear contact lenses, SVLs or PALs. Myopia by cycloplegic autorefraction (Nidek ARK 700A) and ocular components, including lens thickness, by A-scan ultrasound (Sonomed A2500) were measured annually over 11 years. Analyses of lens thickness were based on right eye data from 426 children with refractions fit with Gompertz functions. Longitudinal lens thickness measurements for each participant were fit with a third-degree polynomial function, and average polynomial functions were calculated for three groups of children previously identified based on Gompertz functions: 6–7 years at baseline (n = 40), ≥8 years with progressing myopia (n = 329), and ≥8 years with non-progressing myopia (n = 56). ANOVAs were used for comparing the lens curve-based parameters among the three groups. Associations between lens and Gompertz parameters were assessed using Pearson correlations. Results Overall, between 6 and 18 years the lenses thinned and then thickened, with the minimum value of 3.37 ± 0.15mm reached at 11.56 ± 2.04 years. The minimum lens thickness did not differ among the three myopia groups (p = 0.09), nor was it correlated with the amount of myopia at lens minimum or amount of final myopia (r's = −0.01 and −0.03, respectively, p's>0.05). Conclusion As a similar pattern of change in lens thickness with age was found in all children, whether their myopia progressed or not, these results suggest that the association of lens thinning and thickening with the course of myopia is coincidental rather than causal.

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Section: Discussionsupporting

confidence: 90%

Longitudinal Changes in Lens Thickness in Myopic Children Enrolled in the Correction of Myopia Evaluation Trial (COMET)

Gwiazda

Norton²,

Hou

et al. 2015

Current Eye Research

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“…However for this population of esotropic monkeys, which does not include many of the esotropic monkeys with high degrees of anisometropia, the interocular differences in vitreous chamber only explained 13% of the variance in the degree of anisometropia. The resulting correlation was much weaker than that typically observed in monkeys with vision-induced refractive errors (Arumugam, Hung, To, Holden & Smith III, 2014, Qiao-Grider, Hung, Kee, Ramamirtham & Smith III, 2010, Smith III et al, 2012). In contrast, in the prism-reared macaques, the observed anisometropias were strongly correlated with interocular differences in vitreous chamber depth (Figure 11B; r 2 = 0.77).…”

Section: Resultscontrasting

confidence: 69%

Observations on the relationship between anisometropia, amblyopia and strabismus

et al. 2017

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We investigated the potential causal relationships between anisometropia, amblyopia and strabismus, specifically to determine whether either amblyopia or strabismus interfered with emmetropization. We analyzed data from non-human primates that were relevant to the co-existence of anisometropia, amblyopia and strabismus in children. We relied on interocular comparisons of spatial vision and refractive development in animals reared with 1) monocular form deprivation; 2) anisometropia optically imposed by either contact lenses or spectacle lenses; 3) organic amblyopia produced by laser ablation of the fovea; and 4) strabismus that was either optically imposed with prisms or produced by either surgical or pharmacological manipulation of the extraocular muscles. Hyperopic anisometropia imposed early in life produced amblyopia in a dose-dependent manner. However, when potential methodological confounds were taken into account, there was no support for the hypothesis that the presence of amblyopia interferes with emmetropization or promotes hyperopia or that the degree of image degradation determines the direction of eye growth. To the contrary, there was strong evidence that amblyopic eyes were able to detect the presence of a refractive error and alter ocular growth to eliminate the ametropia. On the other hand, early onset strabismus, both optically and surgically imposed, disrupted the emmetropization process producing anisometropia. In surgical strabismus, the deviating eyes were typically more hyperopic than their fellow fixating eyes. The results show that early hyperopic anisometropia is a significant risk factor for amblyopia. Early esotropia can trigger the onset of both anisometropia and amblyopia. However, amblyopia, in isolation, does not pose a significant risk for the development of hyperopia or anisometropia.

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“…1C & D). In both form deprivation myopia (FDM) and negative lens-induced myopia (LIM), there are minimal changes in corneal shape or in the power of the crystalline lens (Pickett-Seltner et al, 1987; Qiao-Grider et al, 2010; Schaeffel et al, 1988; Siegwart, Jr. and Norton, 1998). …”

Section: Animal Studiesmentioning

confidence: 99%

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

Norton

Siegwart

2013

Experimental Eye Research

182

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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Nature of the refractive errors in rhesus monkeys (Macaca mulatta) with experimentally induced ametropias

Cited by 19 publications

References 111 publications

Longitudinal Changes in Lens Thickness in Myopic Children Enrolled in the Correction of Myopia Evaluation Trial (COMET)

Longitudinal Changes in Lens Thickness in Myopic Children Enrolled in the Correction of Myopia Evaluation Trial (COMET)

Observations on the relationship between anisometropia, amblyopia and strabismus

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

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