Development of experimental myopia using a primate model (tree shrews) and the investigation for the mechanisms of myopia.

为了研究树鼠眼睛的变化，我们研究了测量(1)眼轴长度，(2)屈光不正，(3)眼睛荧光的方法，以及估计血-视网膜屏障(BRB)的新的计算机模拟方法。此外，通过眼底检查和血管造影对正常树鼠的眼底特征进行了研究。对树鼠正常眼发育进行了研究，以确定其结构和晶状体自身荧光的变化。在正常树鼠中，我们发现随着年龄的增长，角膜曲率增加，晶状体增厚，玻璃体长度减少。这些变化在出生后100天迅速发生，然后在250天后缓慢发生。晶状体的自体荧光强度随年龄增长而增加。我们还研究了一种诱导形式剥夺的方法。未成熟的树鼠，在形觉剥夺后的第二天开始，近视改变明显，玻璃体腔延长。在形体剥夺诱导后15天，这两种变化都达到了显著水平。这一趋势在动物成熟时发生了变化；在成熟的树鼠中，诱导形觉剥夺的眼睛在同一时期没有表现出近视变化。这表明，在成年动物中，对形觉剥夺性近视的易感性可能会下降。诱导形觉剥夺后45d，晶状体自体荧光值和晶状体内膜通透性增加。然而，血-房水屏障的指标--房水值并没有改变。这些结果表明近视改变可能与形觉剥夺性近视树鼠视网膜功能受损密切相关。同时晶状体自体荧光增强可能提示近视发展引起的眼内环境平衡受损。

To investigate changes in tree shrew eyes, we studied the methodology for measuring (1) axial length, (2) refractive error, (3) ocular fluorescence, and the new computer simulation method to estimate the blood-retinal barrier (BRB). In addition, the fundus features of normal tree shrews were studied by fundus examination and angiography. The normal ocular development in tree shrews was studied to determine the structural and lens autofluorescence changes. In normal tree shrews, we found that with aging the corneal curvature increased, the lens thickened, and the length of the vitreous decreased. These changes occurred rapidly by 100 days after birth, then occurred slowly after 250 days. The degree of lens autofluorescence increased with age. We also investigated a method to induce form deprivation. In immature tree shrews, beginning the day after form deprivation was induced myopic changes were apparent and the vitreous cavity elongated. Both of these changes reached significant levels at 15 days following induction of form deprivation. This tendency changed when the animal reached maturity ; in mature tree shrews the eyes in which form deprivation was induced did not show the myopic changes during the same period. This suggests that susceptibility to form deprivation myopia may decline in mature animals. Lens autofluorescence values and the inward permeability of the BRB increased by 45 days after form deprivation was induced. However, the aqueous values, the indices of the blood-aqueous barrier, did not change. These findings indicate that myopic changes may be closely related to impaired retinal function based on the BRB permeability in tree shrews with form deprivation myopia. Furthermore, increased lens autofluorescence at the same time may indicated ocular homeostatic impairment caused by the development of myopia.