Scleral changes induced by atropine in chicks as an experimental model of myopia

Gallego, Patricia; Martínez‐García, Carmen; Pérez-Merino, Pablo; Ibares‐Frías, Lucía; Mayo-Íscar, Agustín; Merayo‐Lloves, Jesús

doi:10.1111/j.1475-1313.2012.00940.x

Cited by 48 publications

(35 citation statements)

References 45 publications

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“…5a). In agreement with a previous study [44], the fibrous layer became thinner in Intravitreal 7-MX injections did not prevent the decline of DOPAC in vitreous and retina in eyes covered with diffusers. As shown in Figure 6b and e, DOPAC content was significantly lower in deprived eyes compared to contralateral control eyes in both treatment groups (p 0.001 in vitreous and retina of both groups), but there was no difference between the 7-MX-and vehicle-injected eyes (vitreous: 2.76 ± 0.12 vs. 2.74 ± 0.14 ng/100 mg wet weight, p 0.05; Fig.…”

Section: Results Of Tube-feeding Of 7-mxsupporting

confidence: 92%

Effects of 7-Methylxanthine on Deprivation Myopia and Retinal Dopamine Release in Chickens

Liu

Schaeffel

Trier³

et al. 2019

Ophthalmic Res

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Introduction: Intake of 7-methylxanthine (7-MX), an adenosine receptor (AR) antagonist, has been shown to inhibit school myopia in children and deprivation myopia in rhesus monkeys, but the underlying mechanisms are not known. Also retinal dopamine seems to be involved in the control of eye growth, and in the brain, ARs and dopamine receptors interact widely by heteromerization. We have studied whether 7-MX can inhibit deprivation myopia also in chickens and whether inhibition may involve the retinal dopamine system. Methods: 7-MX was applied by either tubefeeding (100 µg/g body weight, twice a day) or intravitreal injection (12.5 µg, every other day). Forty-eight 2-week-old chicks wore unilateral diffusers and were randomly assigned to either the tube-feeding group (involving 7-MX, vehicle [xanthan gum], or no feeding, for 13 days) or the intravitreal injection group (involving 7-MX, vehicle, or DMSO, for 8 days). Refractions (REs), ocular biometry (AL, VCD), and scleral and choroidal thickness (ChT) were measured before and after treatment. Dopamine and dihydroxyphenylacetic acid (DOPAC) content were determined in retina and vitreous by HPLC at the end of the experiments. Results: No matter how 7-MX was applied, it did not inhibit deprivation myopia in chicks. No significant differences were observed in RE, VCD, AL, and scleral fibrous layer thickness. Feeding 7-MX produced more choroidal thinning in the open contralateral eye compared to control eyes in the vehicle-fed group (-40 ± 14 vs. -1 ± 7 µm, unpaired t test, p < 0.05). DOPAC and dopamine concentration in vitreous and DOPAC concentration in retina did not change with 7-MX. Vitreal dopamine content was significantly decreased in deprived eyes in the groups fed with the vehicle xanthan gum (paired t test, p < 0.01) but not in 7-MX-treated eyes, perhaps indicating a small effect of 7-MX on dopamine. Conclusions: In our study, 7-MX had no effect on DM in chicks and only minor effects on ChT and retinal dopamine. It remains unclear whether 7-MX inhibits myopia through a retinal mechanism or whether it acts directly on choroid and sclera. In the latter case, the finding that myopia is suppressed in mammals but not birds might be explained by differences in scleral structure.

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Section: Results Of Tube-feeding Of 7-mxsupporting

confidence: 92%

Effects of 7-Methylxanthine on Deprivation Myopia and Retinal Dopamine Release in Chickens

Liu

Schaeffel

Trier³

et al. 2019

Ophthalmic Res

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“…Muscarinic antagonist control of myopia has also been linked with the sclera. 20 Unanswered questions remain as to the full signaling pathway by which atropine prevents axial myopia in humans and animal models.…”

Section: Discussionmentioning

confidence: 99%

Therapeutic effect of atropine 1% in children with low myopia

Huang

et al. 2015

Journal of American Association for Pediatric Ophthalmology and

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“…Scleral fibroblast cells carry all five muscarinic receptors on their cell membrane and binding to atropine may interfere with scleral remodeling. 32 The inhibitory effect of atropine is not likely executed through an accommodative mechanism, because the inhibitory effect of atropine on eye growth is also observed in chicks, and these animals activate the ciliary muscle via nicotine receptors rather than the muscarinic receptor. 30…”

Section: Discussionmentioning

confidence: 99%

Effectiveness study of atropine for progressive myopia in Europeans

Polling

Kok

Tideman

et al. 2016

Eye

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PurposeRandomized controlled trials have shown the efficacy of atropine for progressive myopia, and this treatment has become the preferred pattern for this condition in Taiwan. This study explores the effectiveness of atropine 0.5% treatment for progressive high myopia and adherence to therapy in a non-Asian country.MethodsAn effectiveness study was performed in Rotterdam, the Netherlands. Overall 77 children (mean age 10.3 years±2.3), of European (n=53), Asian (n=18), and African (n=6) descent with progressive myopia were prescribed atropine 0.5% eye drops daily. Both parents and children filled in a questionnaire regarding adverse events and adherence to therapy. A standardized eye examination including cycloplegic refraction and axial length was performed at baseline and 1, 4, and 12 months after initiation of therapy.ResultsMean spherical equivalent at baseline was −6.6D (±3.3). The majority (60/77, 78%) of children adhered to atropine treatment for 12 months; 11 of the 17 children who discontinued therapy did so within 1 month after the start of therapy. The most prominent reported adverse events were photophobia (72%), followed by reading problems (38%), and headaches (22%). The progression rate of spherical equivalent before treatment (−1.0D/year±0.7) diminished substantially during treatment (−0.1D/year±0.7) compared to those who ceased therapy (−0.5D/year±0.6; P=0.03).ConclusionsDespite the relatively high occurrence of adverse events, our study shows that atropine can be an effective and sustainable treatment for progressive high myopia in Europeans.

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Scleral changes induced by atropine in chicks as an experimental model of myopia

Cited by 48 publications

References 45 publications

Effects of 7-Methylxanthine on Deprivation Myopia and Retinal Dopamine Release in Chickens

Effects of 7-Methylxanthine on Deprivation Myopia and Retinal Dopamine Release in Chickens

Therapeutic effect of atropine 1% in children with low myopia

Effectiveness study of atropine for progressive myopia in Europeans

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