Choroidal Neovascularization and Retinal Pigment Epithelium, and Laser Photocoagulation Treatment

1. 实验研究了氪激光光凝（PC）在猕猴黄斑区形成脉络膜新生血管（ChNV）。在PC后的自然病程中，ChNV在PC后1 ~ 2周发生，3 ~ 4周发展，5 ~ 8周自行消退。在组织学研究中，我们发现在ChNV发育阶段，未成熟的ChNV通常伴有视网膜色素上皮细胞（RPE）的迁移。在回归阶段，RPE已经增殖到包膜ChNV作为一个单细胞层（封闭）。我们通过术前或术后全身注射碘酸钠（Na 10_3）或玻璃体内注射少量盐酸1鸟氨酸破坏RPE。碘酸钠损伤RPE和光感受器外段，鸟氨酸选择性损伤RPE。在PC之前使用这些药物的眼睛中，ChNV根本没有发展。在发生ChNV后给予这些药物的更多病例中，ChNV在半年内持续生长，没有任何自发消退的证据。组织学上，这些眼睛的RPE未见增生和包膜。这些结果表明，RPE细胞与ChNV的发育和消退密切相关，1)迁移的RPE细胞可诱导ChNV的生长，2)RPE细胞的增殖对ChNV的消退起作用，3)损伤的RPE细胞未表现出这种作用。激光治疗实验性脉络膜新生血管的组织病理学我们研究了激光光凝（PC）治疗实验性脉络膜新生血管（Ch NV）后激光病变的组织病理学过程。我们通过强氪激光PC和成功的1-鸟氨酸盐酸盐玻璃体内注射，在猴子眼睛中制造了发育良好且持久的ChNVs。用染料激光的橙色光束（590nm）处理ChNVs。经染色激光PC后，临床及造影观察，部分病变ChNVs消失，病变变干，部分病变ChNVs生长，病变持续湿润。对PC病变进行组织病理学检查。光镜和电镜检查显示，在干性病变处，视网膜下间隙充满了增殖的RPE细胞，未发现NVs。在湿性病变处，发现大量新血管，视网膜下间隙伴有成纤维细胞样RPE细胞、成纤维细胞和巨噬细胞。这些结果表明，在激光治疗中，闭合ChNV是PC必不可少的，而PC不足会导致NV进一步发展和视网膜下间隙细胞增殖，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