形觉剥夺性近视鸡眼巩膜改变光电镜观察

Structural and ultrastructural changes of the sclera in the form deprived chicks

目的 观察形觉剥夺性近视鸡眼后极部巩膜纤维层、软骨层及二者交界处的改变。方法 采用半透明眼罩遮盖的方法建立鸡眼近视模型 ,2周后检测鸡眼屈光度、眼轴长、赤道径 ,并观察后极部巩膜组织的光镜、电镜改变。结果 2周后遮盖眼的屈光度、眼轴长和赤道径较对侧未处理眼明显增大 (P <0 .0 1)。遮盖眼后极部巩膜软骨层变厚 ,纤维层变薄 ,二者交界处可见间充质细胞。纤维层胶原纤维直径变小 ,纤维间空间增大。结论 形觉剥夺刺激鸡眼巩膜纤维层向软骨层转化 ,巩膜纤维层的改变与哺乳动物巩膜的改变相似。

Objective To observe the changes of cartilaginous layer, fibrous layer, and the border between the two layers of sclera in form deprivation myopia in ch icks. Methods Form deprivation myopia was established in chicks with translucent plastic occluder.Two weeks later, optical measures such as refraction, axial le n gth, equatorial diameter, and structure measures of posterior sclera with light and electron microscopy were made. Results There were obvious abnormalities in g rowth and refraction status in form deprivation eyes. Axial length and equatoria l diameter were significantly different between form deprivation eyes and normal control eyes (P<0.01). Histopathologic changes such as thickening of sclera car tilaginous layer as well as thinning in sclera fibrous layer were found. We also found the transitional cells between the two layers. The collagen fibrillar dia meters of fibrous sclera in the posterior segment of myopic eyes were obviously smaller and the space between the fiber were obviously larger than that of contr ol eyes. Conclusion Form deprivation stimulates the exchange of the fibrous s clera into the cartilaginous sclera in chicks. Changes in the fibrous sclera in myopic eyes of chicks seem to be similar to sclera changes in myopic eyes of mam mals.