糖尿病小鼠血管内皮生长因子表达与血糖、病程的关系

血管内皮生长因子 (ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ ,ＶＥＧＦ)是一种相对分子质量为 34× 10 3～ 45× 10 3 的碱性蛋白质 ,具有强烈的促进血管内皮细胞增生的作用[1] 。有关它在糖尿病视网膜病变 (ｄｉａｂｅｔｉｃｒｅｔｉｎｏｐａｔｈｙ ,ＤＲ)发病中的作用 ,国内已有报道[1] ,但尚缺乏应用免疫组织化学技术对其在病变的视网膜中的定位、定量表达进行的研究。为了探讨ＶＥＧＦ在ＤＲ的表达变化以及与血糖、糖尿病病程之间的相互关系 ,我们用血糖测定、光镜ＨＥ染色及免疫组织化学法等技术 ,对不同月龄…     

人玻璃体膜及视网膜前膜免疫组化研究

目的 鉴定人玻璃体膜及视网膜前膜的细胞成分。方法 对增生性玻璃体视网膜病变（ＰＶＲ）１２例和外伤性ＰＶＲ８例患者经玻璃体手术取出的增生膜标本,用鼠抗人角蛋白、波形蛋白、神经胶质纤维酸性蛋白（ＧＦＡＰ）和ＣＤ１４等４种单抗做免疫组织化学ＡＢＳ法染色并观察。结果 １２例ＰＶＲ膜抗角蛋白染色均为阳性,６例抗ＧＦＡＰ阳性,１０例抗ＣＤ１４阳性;８例外伤性ＰＶＲ膜２例抗角蛋白染色阳性,７例抗ＧＦＡＰ阳性,３     

视网膜静脉阻塞患者血浆和泪液中血管内皮生长因子表达的研究

目的　观察视网膜静脉阻塞（ｒｅｔｉｎａｌｖｅｉｎｏｃｃｌｕｓｉｏｎ,ＲＶＯ）患者血浆和泪液中血管内皮生长因子（ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ,ＶＥＧＦ）的表达情况。方法　选取我院确诊的２８例ＲＶＯ患者,收集血浆和泪液样本,通过酶联免疫吸附试验测定ＶＥＧＦ表达水平,在１ｄ、２周和４周使用光学相干断层扫描检查中央视网膜厚度（ｃｅｎｔｒａｌｒｅｔｉｎａｌｔｈｉｃｋｎｅｓｓ,ＣＲＴ）,另选健康志愿者３０人作为对照组,比较两组血浆和泪液中ＶＥＧＦ、ＣＲＴ表达差异。结果　各时间点,ＲＶＯ组血浆中ＶＥＧＦ表达水平显著高于对照组（均为Ｐ＜０．０５）,１ｄＲＶＯ组泪液ＶＥＧＦ表达水平与对照组差异无统计学意义（Ｐ＞０．０５）。ＲＶＯ组血浆和泪液中ＶＥＧＦ表达水平呈微弱正相关（Ｐ＜０．０５）,而对照组中这种相关性稍强（Ｐ＜０．０５）。两组２周后ＣＲＴ明显增加,１ｄ与２周ＣＲＴ值差异均有统计学意义（均为Ｐ＜０．０５）,２周与４周差异均无统计学意义（均为Ｐ＞０．０５）,各时间段ＲＶＯ组与对照组差异有统计学意义（Ｐ＜０．０５）。结论　ＲＶＯ患者泪液中ＶＥＧＦ表达水平及ＣＲＴ与健康人比较显著升高,血浆与泪液中ＶＥＧＦ表达水平的变化有一致性,泪液检测作为非侵入性的检测方式,对ＲＶＯ的早期诊断有较高的临床应用价值。     

增殖性视网膜病变玻璃体切割物的细胞学及免疫组化研究

目的探讨不同视网膜增殖性疾病细胞增殖的特征及其异同。方法采用３种特异性抗原，即抗人细胞角蛋白（ｃｙｔｏｋｅｒａｔｉｎ，ＣＫ），抗胶质纤维酸性蛋白（ｇｌｉａｌｆｉｂｒｉｌａｒｙａｃｉｄｉｃｐｒｏｔｅｉｎ，ＧＦＡＰ），抗肌动蛋白（Ａｃｔｉｎ）对２８例临床上不同的视网膜疾病的增殖膜及玻璃体切除液样本进行免疫细胞化学研究。结果增殖性玻璃体视网膜病变（ｐｒｏｌｉｆｅｒａｔｉｖｅｖｉｔｒｅｏｒｅｔｉｎｏｐａｔｈｙ，ＰＶＲ）的增殖特征以胶质细胞和视网膜色素上皮细胞（ｒｅｔｉｎａｌｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉｕｍ，ＲＰＥ）为主，二者在ＰＶＲ发病中作用不同。增殖性糖尿病视网膜病变（ｐｒｏｌｉｆｅｒａｔｉｖｅｄｉａｂｅｔｉｃｒｅｔｉｎａｏｐａｔｈｙ，ＰＤＲ）玻璃体内出现ＲＰＥ细胞可加剧增殖膜收缩。增殖膜血管壁上肌动蛋白含量增多可能对周细胞脱落起促进作用。结论玻璃体内细胞增殖与生长因子水平升高可能是增殖性病变日益加剧的重要机制和原因之一。     

玻璃体内注射色素上皮源性因子对大鼠早期糖尿病视网膜病变的保护作用

目的　观察玻璃体内注射色素上皮源性因子（ｐｉｇｍｅｎｔｅｐｉｔｈｅｌｉｕｍ-ｄｅｒｉｖｅｄｆａｃｔｏｒ,ＰＥＤＦ）对ＳＤ糖尿病大鼠视网膜ＰＥＤＦ、血管内皮生长因子（ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ,ＶＥＧＦ）、炎性相关因子细胞间黏附分子-１（ｉｎｔｅｒｃｅｌｌｕｌａｒｃｅｌｌａｄｈｅｓｉｏｎｍｏｌｅ-ｃｕｌｅ-１,ＩＣＡＭ-１）和单核细胞趋化蛋白-１（ｍｏｎｏｃｙｔｅｃｈｅｍｏｔａｃｔｉｃｐｒｏｔｅｉｎ-１,ＭＣＰ-１）以及细胞通透性相关因子紧密连接蛋白-１（ｚｏｎｕ-ｌａｏｃｃｌｕｄｅｎｓ-１,ＺＯ-１）和蛋白激酶Ｂ（ｐｒｏｔｅｉｎｋｉｎａｓｅＢ,ＰＫＢ,又称Ａｋｔ）表达的影响,探讨ＰＥＤＦ对早期糖尿病视网膜病变的保护作用。方法　选取６～８周龄ＳＤ大鼠６０只,随机分为４组:正常对照组（ＣＯＮ组）、糖尿病组（ＤＭ组）、糖尿病生理盐水注射组（ＤＭ＋ＮＳ组）和糖尿病ＰＥＤＦ注射组（ＤＭ＋ＰＥＤＦ组）。链脲佐菌素诱导建立糖尿病模型后第１周、２周、３周时,ＤＭ＋ＰＥＤＦ组大鼠玻璃体内注射ＰＥＤＦ,而ＤＭ＋ＮＳ组注射同样体积的生理盐水。第４周时处死大鼠,摘出眼球,进行视网膜组织病理学及电镜观察。并采用免疫组织化学方法检测视网膜ＰＥＤＦ、ＶＥＧＦ、ＩＣＡＭ-１、ＭＣＰ-１以及ＺＯ-１、Ａｋｔ的表达情况。结果　糖尿病大鼠均造模成功。４周糖尿病病程尚不能导致明显的视网膜新生血管形成。在透射电镜下,ＤＭ组大鼠视网膜可见神经节细胞水肿,线粒体肿胀变大,基质肿胀明显,可见大部分或全部的嵴消失,部分双侧膜融合,粗面内质网扩张,而玻璃体内ＰＥＤＦ注射可以明显地改善这一病理改变。ＤＭ组大鼠ＰＥＤＦ主要表达于视网膜神经纤维层、神经节细胞层以及内丛状层、光感受器基质以及色素上皮层、脉络膜等部位;ＶＥＧＦ主要表达于神经节细胞层,ＩＣＡＭ-１主要表达在光感受器层,ＭＣＰ-１主要表达在视网膜内层细胞,包括节细胞层和内核层,ＺＯ-１蛋白主要表达于内核层的细胞以及神经节细胞,Ａｋｔ主要表达于内丛状层以及脉络膜的细胞浆中。同ＣＯＮ组相比,ＤＭ组、ＤＭ＋ＮＳ组视网膜中ＰＥＤＦ、ＶＥＧＦ表达差异均无统计学意义（均为Ｐ＞０．０５）,而ＩＣＡＭ-１、ＭＣＰ-１表达增加,ＺＯ-１、Ａｋｔ表达减少,差异均有统计学意义（均为Ｐ＜０．０５）。ＤＭ＋ＰＥＤＦ组大鼠视网膜中ＰＥＤＦ、ＶＥＧＦ的表达较ＤＭ组和ＤＭ＋ＮＳ组差异均无统计学意义（均为Ｐ＞０．０５）,但ＩＣＡＭ-１、ＭＣＰ-１表达减少,ＺＯ-１、Ａｋｔ表达增多,差异均有统计学意义（均为Ｐ＜０．０５）。结论　ＰＥＤＦ可以明显地改善糖尿病视网膜病变早期视网膜神经节细胞的损害,通过减少炎性因子和增加细胞连接蛋白而减轻血-视网膜屏障的破坏,从而对早期糖尿病视网膜病变起一定的防治作用。     

表皮生长因子受体家族在翼状胬肉上皮内的异常表达

目的 了解表皮生长因子受体（ｅｐｉｄｅｒｍａｌ ｇｒｏｗｔｈ ｆａｃｔｏｒ ｒｅｃｅｐｔｏｒ,ＥＧＦＲ）家族的ＥＧＦＲ、ＥｒｂＢ２及ＥｒｂＢ３蛋白在翼状胬肉上皮内的表达。方法 用免疫荧光组织化学及Ｗｅｓｔｅｒｎ ｂｌｏｔ地１５例初发期翼状胬肉患者切除的翼状胬肉组织进行ＥＧＦＲ、ＥｒｂＢ２及ＥｒｂＢ３蛋白的检测,并与正常人结膜组织进行对照。结果 免疫荧光组织化学染色显示,在正常结膜上皮中,ＥＧＦＲ蛋     

视网膜母细胞瘤的细胞来源与分化研究

对５０例视网膜母细胞瘤石蜡标本作免疫组织化学（神经元特异性烯醇化酶ｎｅｕｒｏｎ ｓｐｅｃｉｆｉｃ ｅｎｏｌａｓｅ，ＮＳＥ），神经胶质原纤维酸性蛋白及组织化学（胶性铁粘多糖５０例及核糖核酸２例）研究，１３例作透射电视观察。Ｒｂ细胞显示不同程度的ＮＳＥ阳性或阴性反应。大多数Ｆ－Ｗ及Ｈ－Ｗ菊花团呈阳性ＮＳＥ反应，花状饰呈阴性或弱阳性。ＧＦＡＰ阳性细胞主要位于肿瘤边缘及血管周围，少数掺杂于ＮＳＥ阳性细胞之     

视网膜前膜IgG、C_3、胶原和Ki－M_7免疫组织化学研究

采用免疫组织化学染色对１２例增殖性玻璃体视网膜病变的视网膜前膜组织进行检查。光镜下，８例前膜主要由视网膜色素上皮细胞、成纤维细胞样细胞、巨噬细胞及胶原纤维构成；免疫荧光染色的前膜组织分别呈ＩｇＧ、补体Ｃ３、Ⅲ型胶原及Ｋｉ－Ｍ７抗体反应阳性。表明视网膜前膜中有体液免疫成分介入，巨噬细胞在ＰＶＲ形成的免疫反应机制中可能起重要作用。     

视网膜前膜IgG,C3,胶原和Ki—M7免疫组织化学研究

利用免疫组织化学染色对１２例增殖性玻璃体视网膜病变的视网膜前膜组织进行检查。光镜下，８例前膜主要由视网膜色素上皮细胞，成纤维细胞样细胞、巨噬细胞及胶原纤维构成，免疫荧光染色的前膜组织分别呈ＩｇＧ、补体Ｃ３、Ⅲ型胶原及Ｋｉ－Ｍ７抗体反应阳性，表明视网膜前膜中有体液免疫成分介入，巨噬细胞在ＰＶＲ形成的反应机制中可能起重要作用。     

血管内皮生长因子在糖尿病新生血管性青光眼虹膜组织中的表达

目的 探讨血管内皮生长因子（ＶＥＧＦ）在糖尿病虹膜新生血管发生中的作用。方法 收集糖尿病新生血管性青光眼虹膜组织２５例,免疫组织化学染色,光镜观察。结果 ＶＥＧＦ在新生血管性青光眼虹膜组织中的阳性率为１００％,而在对照组中的阳性率为２１．０５％,χ＾２＝２９．９５,Ｐ〉０．００５。ＶＥＧＦ主要表达于虹膜表面的新生血管内皮细胞中。结论 糖尿病新生血管性青光眼虹膜组织中ＶＥＧＦ表达异常增高,虹膜表面的新生血管内皮细胞可以通过自分泌ＶＥＧＦ来刺激新生血管快速生长。     

Expression of Pigment Epithelium-Derived Factor and Vascular Endothelial Growth Factor in Fibrovascular Membranes from Patients with Proliferative Diabetic Retinopathy

Purpose

The expression of pigment epithelium-derived factor (PEDF), a strong inhibitor of angiogenesis, has not been examined in human ocular fibrovascular membranes, to the best of our knowledge. The purpose of this study was to determine whether PEDF is expressed in the fibrovascular membranes in eyes of patients with proliferative diabetic retinopathy (PDR), and to compare the expression of PEDF with that of vascular endothelial growth factor (VEGF).

Methods

The expression of PEDF and VEGF in the fibrovascular membranes excised during vitreous surgery in eight cases of PDR was determined by immunohistochemistry.

Results

VEGF was strongly expressed in the endothelial cells of newly formed vessels in the fibrovascular membranes. In contrast, PEDF was weakly expressed in the endothelial cells and was prominently expressed in the extracellular matrix and fibrous tissue surrounding the new vessels.

Conclusions

Our results suggest that PEDF, along with VEGF, may modulate the formation of fibrovascular membranes in patients with PDR.?Jpn J Ophthalmol 2006;50:116–120 © Japanese Ophthalmological Society 2006     

Colocalization of Tie2, angiopoietin 2 and vascular endothelial growth factor in fibrovascular membrane from patients with retinopathy of prematurity

PURPOSE: The tyrosine kinase receptor Tie2 and its ligands, the angiopoietins (Angs), play important roles in vascular integrity and neovascularization, modulating vascular endothelial growth factor (VEGF) activity. To elucidate the potential role of Angs and the Tie2 system in retinopathy of prematurity (ROP), we have investigated the expression of Angs, Tie2 and VEGF within fibroproliferative membranes in ROP. METHODS: Fibroproliferative membranes were obtained from 38 cases with stage 5 ROP at the time of vitrectomy. Membranes were fixed in formalin and embedded in paraffin. Each specimen was serially sectioned for immunohistochemistry. Polyclonal antibodies specific for Ang1, Ang2, Tie2 and VEGF were used for immunostaining. Immunoreactivity for von Willebrand factor (factor VIII) was also assessed to confirm the identity of vascular endothelial cells. RESULTS: Positive staining for Tie2 was observed in 23 of 38 specimens (60.5%). Tie2 was localized in vascularized regions of fibrovascular membranes and was co- expressed with VEGF and factor VIII. Ang2 stained positively in 18 of 38 (47.3%) serial sections where Tie2 was present, and was also co-expressed with VEGF and factor VIII. Ang1 was not generally observed in these specimens (3/38). CONCLUSIONS: VEGF and Ang2-Tie2 interactions may play an important role in the pathogenesis of ROP.     

Expression of pigment epithelium derived factor and vascular endothelial growth factor in choroidal neovascular membranes and polypoidal choroidal vasculopathy

AIMS: To determine whether pigment epithelium derived factor (PEDF), a protein that inhibits angiogenesis, is expressed in human choroidal neovascular membranes (CNVMs) and in tissues from an eye with polypoidal choroidal vasculopathy (PCV). In addition, to compare the expression of PEDF with that of vascular endothelial growth factor (VEGF), a known stimulator of angiogenesis, in these tissues. METHODS: CNVMs, associated with age related macular degeneration (AMD), angioid streaks, and PCV, were obtained during surgery. The expression of PEDF and VEGF in the excised subretinal fibrovascular membranes was determined by immunohistochemistry. RESULTS: PEDF and VEGF were strongly expressed in the vascular endothelial cells and retinal pigment epithelial (RPE) cells in the CNVMs where numerous new vessels were prominent (clinically active CNVMs). On the other hand, immunoreactivity for PEDF and VEGF was weak in the new vessels where fibrosis was prominent (clinically quiescent CNVMs). However, the RPE cells were still positive for PEDF and VEGF. The specimens from the eye with PCV also showed strong expression of PEDF and VEGF in the vascular endothelial cells and the RPE cells. CONCLUSION: Because PEDF is an inhibitor of ocular angiogenesis and an inhibitor of ocular cell proliferation, our results suggest that PEDF along with VEGF may modulate the formation of subfoveal fibrovascular membranes.     

血小板源性生长因子对增生性玻璃体视网膜病变增生膜形成的影响

目的 探讨血小板源性生长因子（platelet-derived growth factor,PDGF)在增生性玻璃体视网膜病变（proliferative vitreoretinopathy,PVR)增生膜形成中的作用及PVR增生膜中是否存在PDGF的分泌细胞与靶细胞。方法 选择PVR患者的手术标本,其中视网膜前膜（epiretinal membrane,ERM)和视网膜下膜（subretinal membrane,SRM)标本各7例。采用免疫电镜方法检测PDGF及其受体在ERM、SRM中的表达及其与ERM、SRM中两种主要细胞成分即视网膜色素上皮细胞和神经胶质细胞的关系。结果 PDGF－A基7例ERM中均表达阳性,在7例SRM中5例表达阳性,标记物主要位于ERM、SRM部分细胞的胞质中。PDGF－B在7例ERM中均表达阳性,在6例SRM中5例表达阳性,标记物主要位于SRM、SRM的部分细胞胞质中,尤其集中于细胞质内一些电子密度高的椭圆形或不规则形的分泌颗粒中。提示PDGF可由ERM、SRM局部细胞产生,其在ERM、SRM的发病中起重要作用。本实验中PDGF－A和PDGF－B分别与细胞角蛋白和神经胶质纤维酸性蛋白双标记,结果显示细胞角蛋白标记阳性的细胞即视网膜色素上皮细胞和神经胶质纤维酸性蛋白标记阳性细胞－神经胶质细胞中的PDGF－A、PDGF－B蛋白表达阳性,表明视网膜色素上皮细胞和神经胶质细胞是PDGF的分泌细胞。结论 PDGF可由PVR增生膜中的细胞产生,在PVR的发病中起重要作用。视网膜色素上皮细胞和神经胶质细胞是PDGF的分泌细胞,从而为自分泌物、旁分泌机制提供依据。     

玻璃体腔注射抗血管内皮生长因子单克隆抗体bevacizumab对增生型糖尿病视网膜病变纤维血管膜中整合素链接激酶表达的影响

目的 观察玻璃体腔注射抗血管内皮生长因子单克隆抗体bevacizumab(商品名Avastin)对增生型糖尿病视网膜病变(PDR)纤维血管膜中整合素链接激酶(ILK)表达及视网膜血管内皮细胞数量的影响.方法 玻璃体切割手术中取出的24例PDR患者的视网膜前纤维血管膜,其中12例患者手术前1周玻璃体腔单次注射bevaei...     

Fibrovascular proliferation and retinal detachment after intravitreal injection of activated macrophages in the rabbit eye

Injection of activated macrophages into the posterior vitreous of the rabbit induced vigorous fibrovascular proliferation over the optic disk and medullary rays, as demonstrated by 3H-thymidine autoradiography. One week after injection, endothelial cells and pericytes of the capillaries near the inner surface of the optic disk and rays were labeled; fibroblast-like cells, which were also labeled, migrated and formed vitreous strands. By the second week after injection, the fibrovascular tissue proliferated most actively, and traction medullary ray detachment and peripapillary retinal fold formation were observed. The cellular proliferation was accompanied by inflammatory cell infiltration. Glial cells within the optic disk, as well as retinal pigment epithelial cells beneath the detached retina, were labeled by 3H-thymidine. These results demonstrate that the fibrovascular proliferation originates from the vessel complex of the optic disk and medullary rays in this experimental model of retinal detachment.     

VEGF localisation in diabetic retinopathy

AIM—To determine the staining pattern of vascular endothelial growth factor (VEGF) at different stages of diabetic retinopathy (including post-laser photocoagulation) and to compare staining in excised fibrovascular and fibrocellular (non-diabetic) preretinal membranes.
METHODS—Immunohistochemical localisation of VEGF, using antibodies raised against VEGF₁₆₅ and VEGF_121,165,189, was carried out on specimens of normal human retina (n=15), diabetic retinas ((a) with no overt retinopathy (n=19), (b) with intraretinal vascular abnormalities but no proliferative retinopathy (n=6), (c) with active proliferative retinopathy (n=6), (d) with no residual proliferative retinopathy after photocoagulation therapy (n=15)), excised diabetic fibrovascular membranes (n=19), and non-diabetic fibrocellular membranes (n=7). The degree and pattern of immunostaining was recorded.
RESULTS—In general, VEGF was absent from the majority of normal retinas. VEGF staining was apparent in most diabetic tissues but the staining pattern was dependent on both the specificity of the antibody used and the category of tissue. Staining with the VEGF₁₆₅ antibody was generally confined to endothelial cells and perivascular regions while the VEGF_121,165,189 antibody was also associated with extravascular components of the inner retina. Intensity of immunostaining of diabetic eyes was dependent on the severity of retinopathy being least in diabetics with no overt retinopathy and greatest in retinas with proliferative retinopathy. Interestingly, the intensity of immunostaining in diabetic retinas which had undergone laser surgery for proliferative retinopathy was reduced to basal levels. Moderate to intense immunostaining was observed in all fibrovascular and fibrocellular membranes examined.
CONCLUSIONS—This study supports a circumstantial role for VEGF in the pathogenesis of both the preclinical and proliferative stages of diabetic retinopathy.

Keywords: vascular endothelial growth factor; VEGF; diabetes; diabetic retinopathy     

Pericyte coverage of retinal and cerebral capillaries

We performed electron microscopic morphometric analyses on capillaries from macular and peripheral retinas of five adult cynomolgous monkeys and three elderly human subjects. Measurements from the monkey retinal capillaries were compared to those made on capillaries from frontal, temporal, parietal, and occipital cerebral cortex of the same animals. We measured the percent coverage of the endothelial lining of the capillaries by pericyte processes, as well as the ratio of the cytoplasmic areas of pericytes and endothelial cells. In addition, we compared the thickness of the capillary basement membranes in three regions: overlying pericytes; overlying endothelial cells; and interposed between pericytes and endothelial cells. In both monkey and human retinas, pericyte processes covered greater than 85% of the circumference of the capillary endothelial tube, whereas pericyte coverage of monkey cerebral capillaries was highly significantly (P less than 0.001) less than that of capillaries in either the macular or peripheral retina. The ratio of pericyte to endothelial cell cytoplasmic areas also was lower in the monkey cerebral cortex than in the retina, though the statistical significance was less than that of the length measurements. In all tissues measured, both from monkeys and humans, the portions of the capillary basement membranes interposed between pericytes and endothelial cells were highly significantly (P less than 0.0001) thinner than the regions of capillary basement membranes covering pericytes and endothelial cells. Considering functions that have been proposed for pericytes, these measurements suggest that regional control of microcirculatory flow and of blood-tissue barrier integrity, as well as control of endothelial cell proliferation, should be much greater in the retina than in the cerebral cortex. Thinner basement membranes between pericytes and endothelial cells may permit more cell membrane contacts between these cells, thus facilitating such control.     

Histopathological study of retinopathy of prematurity]

Using light and electron microscopy, we studied the histopathological findings of retinopathy of prematurity (zone II, stage 3). The infant was born at 32-week gestational period and the birth weight was 1,255 g. He suffered from intracranial hemorrhage and hydrocephalus, and died at 78 days old. The ophthalmoscopic findings of both eyes at 72 days after birth showed that the intermedia was clear. The optic disc and posterior pole showed normal findings. Ridge formation with non-vascularized retina was seen at the equator of all quadrants of the fundus except the nasal quadrant of retina. Light and electron microscopic studies showed the following; in the most periphery of the vascularized retina, endothelial cell proliferation with the capillary lumen of glomeruloid tufts (rearguard) were seen. There were the aggregation of immature mesenchymal cells (vanguard) near to the rearguard. The cytoplasmic organelles of spindle cells in the non-vascularized retina were different from those of surrounding glial cell. Therefore, they were thought to be mesenchymal cells in the non-vascularized retina. Between the vanguard and the rearguard, the proliferative tissues composed of immature endothelial cells and mesenchymal cells extended into the vitreous body through the inner limiting membranes, and they formed the fibrovascular membranes on the retina. It was concluded that fibrovascular proliferation on the retinal surface in the active case of retinopathy of prematurity was composed of immature endothelial cells with vascular lumen and mesenchymal cells.