Molecular Mechanism and i Therapy for Choroidal Neovascularization

血管生成被认为是由刺激因子（如血管内皮生长因子（VEGF））或抑制剂（如色素上皮衍生因子（PEDF））的平衡控制的。我们发现糖尿病视网膜病变眼玻璃体中PEDF水平较低，VEGF水平较高，这说明糖尿病视网膜病变眼中血管生成刺激剂和抑制剂的平衡被打破。此外，增生性玻璃体视网膜病变眼PEDF水平较低。在孔源性视网膜脱离的眼中较高，表明PEDF也控制着眼细胞的增殖。在实验性脉络膜新生血管的形成过程中，血管内皮细胞中有较强的VEGF和PEDF表达，随后逐渐下降，PEDF在RPE细胞中表达。这些发现提示PEDF和VEGF可能调节脉络膜新生血管的形成过程。在人眼中，PEDF和VEGF在活动性脉络膜新生血管（cnvm）和息肉样脉络膜病变的血管内皮细胞和视网膜色素上皮（RPE）细胞中表达强烈，而PEDF和VEGF在静态脉络膜新生血管（cnvm）中表达较弱。我们的结果表明PEDF和VEGF可能调节中央凹下纤维血管膜的形成。PEDF水平随着年龄的增长而下降。在与年龄有关的眼病，特别是与血管生成有关的眼病中，应考虑PEDF水平与年龄的负相关。视网膜色素变性和晚期青光眼组PEDF水平明显低于单纯白内障组。在患有神经视网膜营养不良的眼睛中，PEDF水平较低可能与合成PEDF的视网膜神经节细胞和/或RPE细胞的丧失有关。

Angiogenesis is believed to be controlled by a balance of stimulators such as vascular endothelial growth factor(VEGF), or inhibitors such as pigment epithelium-derived factor(PEDF).We found that the level of PEDF was lower and the level of VEGF was high in the vitreous of eyes with diabetic retinopathy, These results indicate that there is an upset balance of angiogenic stimulators and inhibitors in eye with diabetic retinopathy. In addition, the level of PEDF was lower in eyes with proliferative vitreoretinopathy. and high in eyes with rhegmatogenous retinal detachment, which indicates that PEDF is also controlling ocular cell proliferation.During the development of experimental choroidal neovascularization, VEGF and also PEDF were strongly detected in vascular endothelial cells, then gradually declined and PEDF was expressed in the RPE cells. These findings suggest that PEDF and VEGF may modulate the process of choroidal neovascularization.In human eyes, PEDF and VEGF were strongly expressed in the vascular endothelial cells and retinal pigment epithelial(RPE) cells in active choroidal neovascular membranes(CNVMs) and polypoidal choroidal vasculopathy, whereas PEDF and VEGF, were both weak in quiescent CNVMs. Our results suggest that PEDF along with VEGF may modulate the formation of subfoveal fibrovascular membranes.The PEDF levels decreased with increasing age. The negative correlation of PEDF level and age should be considered in age-related eye diseases especially those associated with angiogenesis.he mean levels of PEDF in eyes with retinitis pigmentosa and advanced glaucoma were significantly lower than that in eyes with cataract alone. The lower levels of PEDF in eyes with neuroretinal dystrophy may be related to the loss of the retinal ganglion cells and/or RPE cells that synthesize PEDF.