Study about Regulation of Scleral Growth-using Experimental Myopia-

(1)视觉剥夺方法与近视发生的关系：白色来角雄雏鸡单眼配戴塑料半透明或黑色护目镜，在12h -明/12h -暗周期下，视轴伸长过度，高度近视。在12h -明/12h -暗循环下，双筒镜佩戴塑料半透明或黑色护目镜时也表现为高度近视，轴向伸长过大。当单眼戴半透明或黑色塑料护目镜时，在24小时黑暗条件下无轴向伸长。(2)组织学研究：在实验性近视巩膜后段，免疫组化技术检测到PCNA、tgf - β、IGF-II、decorin、磷酸酪氨酸表达升高。上述结果提示，实验性近视巩膜后段细胞增殖和基质合成增加，可能受tgf - β、IGF-II等生长因子的调控。电镜观察显示，近视的软骨巩膜发生了活性重构，并提示近视的纤维巩膜内胶原纤维变薄。(3)生化分析：提取tgf - β和bFGF， ELISA定量分析。在实验性近视眼后段，tgf - β升高，bFGF降低。(4)组织培养研究：tgf β、bFGF、TGFalpha、IGF-II、IGF-I、PDGF等生长因子刺激鸡胚巩膜软骨细胞和巩膜成纤维细胞增殖。共培养的RPE细胞也能刺激这些巩膜细胞的增殖。该共培养系统揭示了阿波啡抑制巩膜生长的作用靶点可能是RPE。(5)牛脉络膜拉伸实验：纵向拉伸程度大于圆周拉伸程度。因此，张力可能成为后极方向轴向伸长的因素之一。(6)猴子的实验性近视：一只高度近视的猴子，眼睑缝合剥夺视力，其近视眼出现绒毛膜视网膜萎缩。组织学观察表明，衰老在这一病理变化中起作用。少

(1) Relationship between method of visual deprivation and induction of myopia : White Leghorn male chicks wearing plastic translucent or black goggles monocularyly showed high myopia with excessive axial elongation under 12hr-light/12hrs-dark cycles. When wearing plastic translucent or black goggles binocularly also showed high myopia with excessive axial elongation under 12hrs-light/12hrs-dark cycles. When wearing translucent or black plastic goggles monocularly did not show any axial elongation under 24hrs-dark condition.(2) Histological study : In the posterior segment of experimentally myopic sclera, expression of PCNA,TGFbeta、IGF-II,decorin, phosphotyrosine increased by immunohistochemical technique. These results suggest that cell prolioferation and matrix synthesis are increased in the posterior segment of experimentally myopic sclera, which could be regulated by such growth factors as TGFbeta、IGF-II.Electron microscopic observation suggested that active remodelling occurs in th … More e myopic cartilaginous sclera and suggested the thinner changes of collagen fibrils in the myopic fibrous sclera.(3) Biochemical analysis : TGFbeta and bFGF were extracted and were quantitatively analyzed by ELISA.In the posterior segment of experimentally myopic eyes, TGFbeta increased but bFGF was decreased.(4) Investigation by tissue culture : Cell proliferation of scleral chondrocytes and scleral fibroblasts derived chick embryos was stimulated by such growth factors as TGFbeta , bFGF,TGFalpha、IGF-II,IGF-I and PDGF.Cell proliferation of these scleral cells was also stimulated by co-cultured RPE cells. And this co-culture system revealed that the target of inhibitory effects of apomorphine on scleral growth could be RPE.(5) Tension experiment with bovine choroid : The degree of stretch was greater in the longitudinal direction than in the circular direction. Thus, it may be possible that the tension becomes one of the factors of axial elongation in the direction of the posterior pole.(6) Experimental myopia in monkeys : One of the monkeys with high myopia by visual deprivation by lid-suture, showed chorioretinal atrophy in his myopic eyes. Histological observation suggested that aging playd a role in that pathological change. Less