Predicting future myopia from changes in choroidal thickness.

1995年，Josh Wallman及其同事在幼鸡实验的基础上指出，视网膜后面的脉络膜厚度变化可以被认为是“第三种聚焦眼睛的机制”，因为当焦点平面在视网膜前面时，脉络膜变厚，当焦点平面在视网膜后面时，脉络膜变薄。显然，在这两种情况下，视网膜都移动得更接近焦平面。这些变化发生在眼睛生长发生变化之前，它们的预测力具有重大意义。由于光学相干断层扫描(OCT)的最新进展，脉络膜厚度的增加现在可以非侵入性地测量，并且在人类身上也可以以高分辨率(&lt；10微米)测量。这种变化可以用来预测未来的近视，无论是在动物模型中还是在儿童中。然而，也有一些情况下，即使脉络膜变厚，轴向眼球增长也会增加。我们建议使用鸡的动物模型进行实验，以找出在什么条件下可能会发生这种情况。在一个特殊的“鸡肉竞技场”，将应用人工视觉刺激。此外，由于目前尚不清楚脉络膜厚度的变化如何转化为巩膜生长的变化，我们将通过量化已知的生物标志物来研究从视网膜到脉络膜和巩膜的信号级联的时间过程。我们还将研究黑素对脉络膜厚度的潜在作用。虽然这些实验将在鸡身上进行，但在根据脉络膜厚度变化预测儿童未来近视以及研究通过新型人工视觉刺激范式抑制近视方面，它们具有基本意义。

In 1995, Josh Wallman and colleagues have stated, based on experiments in young chickens, that choroidal thickness changes behind the retina can be considered “a third mechanism of focusing the eye” since the choroid becomes thicker when the focal plane is front of the retina, and thinner when it is behind. Obviously, in both cases, the retina is moved closer to the focal plane. The changes occur before eye growth has changed and their predictive power has major implications. Thanks to recent advances in optical coherence tomography (OCT), an increase in choroidal thickness can now be measured non-invasively and with high resolution (<10 µm) also in humans. Such changes can be used to predict future myopia, both in animal models and children. However, there are cases where axial eye growth increased even though the choroid became thicker. We propose experiments to find out under which conditions this may happen, using the animal model of the chicken. In a special “chicken arena”, artificial visual stimuli will be applied. Furthermore, since it is still not known how choroidal thickness changes translate into scleral growth changes, we will study the time courses of the signalling cascades from retina to choroid and sclera, by quantifying known biomarkers over time. We will also study the potential role of melanopsin on choroidal thickness. While these experiments will be done in chickens, they have fundamental implications when it comes to predicting future myopia also in children from choroidal thickness changes, and studying inhibition of myopia by novel artificial visual stimulation paradigms.