Choroidal Neovascularization and Retinal Pigment Epithelium, and Laser Photocoagulation Treatment

1.脉络膜新生血管（Choroidal Neovascularization，ChNV）与视网膜色素上皮（Retinal Pigment Epithelium，Retinal Pigment Epithelium，Retinal Pigment Epithelium，Retinal Pigment Epithelium，Retinal Pigment Epithelium）的关系用氪激光光凝（Krypton Laser Photocoagulation，PC）在猴眼黄斑区实验性地建立了脉络膜新生血管（Choroidal Neovascularization，ChNV）模型。未成熟的ChNV通常伴有迁移的视网膜色素上皮细胞（RPE）。在消退阶段，RPE已增殖成单细胞层包裹ChNV（封闭）。我们通过在PC前后全身给予亚碘酸钠（Na 10_3）或玻璃体内注射少量1-鸟氨酸盐酸盐来损伤RPE。碘酸钾损伤RPE和视网膜光感受器外节，鸟氨酸选择性损伤RPE。在PC之前给予这些药物的眼中，ChNV根本没有发展。在眼睛里 ...更多信息 在ChNV发生后给予这些药物的病例中，ChNV在半年内持续生长，没有任何自发消退的证据。组织学上，这些眼的RPE细胞未显示出对ChNV的增殖和包被，提示RPE细胞与ChNV的发生和消退有密切的关系：1）迁移的RPE细胞可诱导ChNV的生长; 2）RPE细胞的增殖对ChNV的消退有一定的作用; 3）受损的RPE细胞未显示出这种作用.激光治疗实验性脉络膜新生血管的组织病理学研究我们观察了实验性脉络膜新生血管（ChNV）激光光凝（PC）后激光损伤的组织病理学过程。我们通过强氪激光PC和玻璃体内注射1-鸟氨酸盐酸盐的方法在猴眼内产生发育良好且持久的ChNV。用橙子激光（590 nm）治疗后，临床和X线造影显示，部分病灶ChNV消失，变干，而另一些病灶ChNV生长，呈湿润状态。对这些PC病变进行了组织学研究。光镜和电镜观察发现，在干性病变处，视网膜下腔充满增生的RPE细胞，未见新生血管;在湿性病变处，视网膜下腔可见大量新生血管，并伴有成纤维细胞样的RPE细胞、成纤维细胞和巨噬细胞。而PC不足则诱导NV的进一步发展和视网膜下间隙中的细胞增殖，并导致治疗失败。少

1. Choroidal Neovascularization and the Retinal Pigment EpitheliumChoroidal neovascularization (ChNV) was produced experimentally in the macular area in monkey eyes by krypton laser photocoagulation (PC).In natural course following PC, ChNV occurred in 1 or 2 weeks after PC, and developed in 3 to 4 weeks, thereafter ChNV regressed spontaneously in 5 to 8 weeks.In histological study, we found, at the developing stage of ChNV, immature ChNVs were usually accompanied with migrated retinal pigment epithelial cells (RPE). At the stage of regression, RPE have proliferated to envelope ChNV as a single cell layer (sealing off).We damaged RPE by systemic administration of sodium iodite (Na 10_3) pre or post PC, or intravitreal injection of a small amount of 1 Ornithine hydrochloride. Sodium iodite damaged RPE and the outer segment of the photoreceptors, and Ornithine damaged RPE selectively. In the eyes in which these drugs were administrated before PC, ChNV have not developed at all. In the ey … More es in which these drugs were administrated after development of ChNV, ChNV have lasted and grown in half a year without any evidence of spontaneous regression. Histologically, RPE have not shown proliferation and enveloping to ChNV in these eyes.These results showed RPE cells have close relations to development and regression of ChNV, 1) migrated RPE cells may induce growing of ChN, 2) proliferations of RPE play a role to regression of ChNV, 3) damaged RPE has not shown such a role.2. Histopathology of Laser Treatment for Experimental Choroidal NeovascularizationWe studied histopathological process of lasered lesion following laser photocoagulation (PC) for experimental choroidal neovascularization (Ch NV). We produced well-developed and long-lasting ChNVs in monkey eyes by means of intense Krypton laser PC and succeedingly intravitreal injection of 1-ornithine hydrochloride. Those ChNVs were treated by orange beam (590nm) of dye laser.After dye laser PC, clinically and fluoangiographically, in some lesions, ChNVs disappeared and the lesions became dry, however, the other lesions, ChNVs grew and the lesions lasted in wet condition. Histopathological studies were made for those PC lesions. Light and EM scopy revealed, at the dry lesions, subretinal space was filled with proliferated RPE cells and NVs were not found. At the wet lesions, new vessels were found numerously, accompanied with fibroblast-like RPE cells, fibroblast, and macrophages in subretinal space.These results showed in laser treatment, closure of ChNV is essentially necessary by PC, and insufficient PC induces further development of NV and cellular proliferation in the subretinal space, and causes failure of treatment. Less