Refractive plasticity of the developing chick eye: a summary and update
Refractive plasticity of the developing chick eye: a summary and update
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DOI：
10.1111/opo.12253
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发表时间：
2015-11-01
影响因子：
2.9
通讯作者：
Callender, Murchison G.
中科院分区：
文献类型：
--
作者：
Irving, Elizabeth L.;Sivak, Jacob G.;Callender, Murchison G.
目的总结OPO 1992经典论文：发育中的小鸡眼的屈光可塑性（12:448-452），并讨论屈光发育的最新研究成果。这篇经典论文表明，当将带有刚性隐形眼镜插入的轻型塑料护目镜戴在刚孵出的小鸡的眼睛上时，眼睛对-10到+20度之间的离焦反应准确，尽管远视发展得更快。虽然这种变化主要是由于眼轴长度的变化，但高度远视与角膜变平有关。此外，新孵化的小鸡比9天大的小鸡更能补偿引起的散焦。此外，在孵化当天使用9D屈光透镜可产生2-6D的散光，并且最近视眼子午线与诱导透镜的幂子午线重合。这种散光似乎主要是由于角膜张力。当诱导晶状体平面子午线距睑裂线45°时，其亮度最大。自从我们在1992年发表论文以来，已经证明在各种物种中都可以产生类似的结果，包括；树鼩、狨猴、猴子和鱼。人们已经花费了相当大的努力，试图确定眼睛（如果不是大脑）是如何作为离焦信号的。调节、色差、日变化、散光和高阶单色差都被考虑在内。脉络膜变薄和增厚分别在雏鸡近视和远视发育中起作用。高亮度（15,000勒克斯）增加了小鸡对正透镜的补偿率，降低了对负透镜的补偿率。然而，这些光线水平并不能阻止眼睛完全补偿这两种类型的晶状体。也有研究表明，短时间的正常视力可以防止形式剥夺性近视的发展。最后，外周视网膜在屈光发育中的重要性已被探讨，而设计用于减少相对外周远视的镜片在近视控制方面产生了不同的效果。结论动物模型和人体临床试验越来越多的证据表明，近视的发生与遗传和环境/生活方式有关。然而，我们还远远不能理解这种相互作用是如何发生的。
PurposeTo summarize the OPO 1992 Classic Paper: Refractive plasticity of the developing chick eye (12: 448-452) and discuss recent findings in refractive development.Summary and recent findingsThe classic paper shows that when lightweight plastic goggles with rigid contact lens inserts are applied to the eyes of newly hatched chicks, the eye responds accurately to defocus between -10 and +20D, although hyperopia develops more rapidly. While the changes largely are due to change in axial length, high levels of hyperopia are associated with corneal flattening. Also, newly hatched chicks are better able to compensate for the induced defocus than chicks that are 9days old. In addition, astigmatism of 2-6D can be produced by applying 9D toric inducing lenses on the day of hatching, and the most myopic meridian coincides with the power meridian of the inducing lens. This astigmatism appears to be primarily due to corneal toricity. Furthermore, the greatest magnitude was produced when the plano meridian of the inducing lens was placed 45 degrees from the line of the palpebral fissure. Since our publication in 1992, it has been shown that similar results can be produced in a variety of species, including; tree shrews, marmosets, monkeys and fish. Considerable effort has been spent in trying to determine what the eye uses, if not the brain, as the signal to the sign of the defocus. Accommodation, chromatic aberration, diurnal variation, astigmatism and higher order monochromatic aberrations have all been considered. Choroidal thinning and thickening play a role in myopia and hyperopia development, respectively, in chicks. High light levels (15,000 lux) increase the rate at which chicks compensate for positive lenses and decrease the compensation rate for negative lenses. However these light levels do not prevent the eye from fully compensating for either type of lens. It has also been shown that brief periods of normal vision prevent the development of form deprivation myopia. Finally, the importance of the peripheral retina in refractive development has been explored and lenses designed to reduce relative peripheral hyperopia have resulted in variable effects as far as myopia control is concerned.ConclusionsA growing body of evidence, from both animal models and human clinical trials indicates that the development of myopia is related both to genetics and environment / lifestyle. Nevertheless, we are far from understanding how this interaction takes place.