An experimental model of intravitreal neovascularization in rabbits]

The author developed a consistent model of intravitreal neovascularization in the eyes of pigmented rabbits by incomplete posterior vitreous detachment after air injection followed by implantation of basic fibroblast growth factor (b-FGF; 250 ng or 1 microgram) in the vitreous and simultaneous intravitreal injection of DL-alpha-aminoadipic acid in physical saline solution (1 mg/kg). Newly formed vessels were observed in the proliferative fibrous membrane that surrounded the b-FGF pellet. In fluorescein angiography, we observed fluorescein leakage from the newly formed vessels. Histologically, the newly formed vessels showed fenestration of endothelial cells. This method provides an easy and consistent model to study neovascularization.     

Complications of rigid anterior chamber implants

Despite accurate lens sizing, 100 eyes with rigid anterior chamber implants showed a high incidence of lens-related trauma postoperatively: pigment dispersion (pseudoguttata), angle recession, peripheral anterior synechiae, iris erosion/atrophy, iris holes from stretching, angle fibrosis, haptic tip erosion into sclera and iris, neovascularization of peripheral iris and angle, lens rotation through iridectomy and into ciliary body, lens tilting with corneal endothelial touch, high refractive cylinder with long intraocular lenses, pigment proliferation onto iris surface, partial slippage of the intraocular lens into vitreous following intracapsular procedure, and pupillary-block glaucoma. Vision results were good. Glaucoma and cystoid macular edema rates were low. Bullous keratopathy and retinal detachment didn't occur. High endothelial cell loss was associated with those lenses that "propellered" and those that tilted and touched endothelium. The adverse findings may be static or may represent a continuing process of tissue damage.     

Morphological study of rubeosis iridis induced in animal eyes]

Rubeosis iridis was produced experimentally in rhesus monkey eyes, by means of occlusion of the major retinal vessels of the retina and persistent ocular hypotony. Clinically, rubeosis iridis was recognized 5 days after the procedure. Histopathologically, these vessels developed anteriorly to the iris surface and endothelial fenestrations showed evidence of iris neovascularization. Endothelial cells of the vessels projected toward the internal lumen and showed immaturity. Newly formed vessels originated from the stromal vessels in the iris. This method is an effective experimental model for the induction of rubeosis iridis.     

Neovascularization in the anterior segment of the rabbit eye by experimental anterior ischemia

PURPOSE: To investigate the effects of anterior ischemia accompanied by neither retinal nor choroidal ischemia on the anterior segment of the eye. METHODS: Both long posterior ciliary arteries in the right eye of 14 rabbits were directly cauterized with an electric coagulator. The eyes were enucleated 1, 2, 4, 7, 9 or 14 days after cauterization, then fixed with 4% paraformaldehyde. Semi-thin sections were studied by light microscopy. Several sections were stained with Griffonia simplicifolia lectin, which bound specifically to mammalian vascular endothelium. Other specimens were examined immunohistochemically for vascular endothelial growth factor (VEGF) protein. The tissue specimens of the first postoperative day were studied for expression of VEGF mRNA by in situ hybridization. RESULTS: Atrophy of the iris and ciliary body was seen after the second postoperative day. Corneal neovascularization appeared after 7 days. Neovascularization on the anterior surface of the iris and in the trabecular meshwork was detected after the ninth postoperative day. The proliferative tissues with newly formed vessels obstructed the iridocorneal angle 14 days after the treatment. There was no histological change in either the retina or choroid. Immunohistochemically, VEGF protein was detected in the epithelial and vascular cells of the iris on the first and fourth postoperative day. Expression of VEGF mRNA was detected in the epithelial cells of the ciliary body on the day following the treatment. CONCLUSIONS: Anterior segment ischemia, when unaccompanied by retinal ischemia, causes neovascularization in the cornea, iris and trabecular tissue.     

二肽基肽酶II在正常大鼠眼球各组织中的免疫表达

目的:探讨二肽基肽酶II(dipeptidyl peptidaseII,DPPII)在正常大鼠眼球各组织中的免疫表达。方法:应用抗生物素蛋白-生物素-过氧化物酶复合体法,检测DPPII在正常大鼠眼球各组织中的免疫表达。结果:发现DPPII在角膜上皮细胞、角膜基质层、角膜内皮细胞、睫状体无色素上皮细胞、虹膜色素上皮细胞、晶状体上皮细胞、晶状体纤维、视网膜神经纤维层、神经节细胞、视网膜色素上皮细胞中免疫染色均呈阳性。结论:DPPII存在于角膜上皮细胞、角膜基质层、角膜内皮细胞、睫状体无色素上皮细胞、虹膜色素上皮细胞、晶状体上皮细胞、晶状体纤维、视网膜神经纤维层、神经节细胞、视网膜色素上皮细胞。     

人胎视网膜内调节血管形成因素的研究

目的：研究人胎视网膜内纤维连接蛋白(Fibronectin，Fn)，碱性纤维母细胞生长因子(basic—fibroblast growth factor，b-FGF)和星形胶质细胞对血管两种发生方式的调节作用。 方法：收集13—40周胎儿视网膜86侧，免疫组织化学染色，光镜现察。 结果：梭形细胞、血管内皮细胞均呈Fn免疫阳性反应，梭形细胞前方的基质中有Fn免疫反应物沉积，血管内皮细胞、节细胞和视锥细胞呈b+FGF阳性反应，后两种细胞的出现先于邻近区域血管的形成；星形腔质细胞紧密伴随梭形细胞向锯齿缘迁移，其突起包裹两种方式发生的血管。 结论：Fn、FGF和星形腔质细胞这三种因素对血管发生的两种方式均有促进作用。 （中华眼底病杂志，1996，12：180-182）     

Collagen XVIII/endostatin shows a ubiquitous distribution in human ocular tissues and endostatin-containing fragments accumulate in ocular fluid samples

Background The endostatin domain of type XVIII collagen (ColXVIII) inhibits neovascularization and regulates cell migration and matrix turnover. This study was designed to demonstrate the protein and gene expression patterns of ColXVIII/endostatin in the human eye and to ascertain whether endostatin is detectable in ocular fluid samples.Methods Twenty human eyes enucleated on account of choroidal melanoma were used for immunohistochemical stainings with antibodies against ColXVIII and endostatin. In situ hybridization was used to localize cells responsible for the production of mRNA for ColXVIII. Tear fluid, aqueous humor, and vitreous gel samples were used for Western immunoblotting to detect endostatin fragments in these samples.Results ColXVIII was immunolocalized to almost all ocular structures, namely the basement membranes (BMs) of the corneal and conjunctival epithelia, Descement’s membrane, the anterior border layer and posterior pigmented epithelium of the iris, the BMs of the pigmented and non-pigmented ciliary epithelia, the internal wall of Schlemm’s canal and trabeculae, the ciliary and iris muscle cells, the BMs of the pigment epithelium of the retina, and the internal limiting membrane. Universal expression was seen in the BMs of vascular endothelial cells, and in fibroblasts located in the conjunctiva, the iris, and the ciliary body. Endostatin showed a corresponding pattern, but additional immunostaining was present in the corneal and conjunctival epithelial cells. Most epithelial and mesenchymal cells expressed the mRNA for ColXVIII. Endostatin-containing fragments varying in size were detected in tear fluid, aqueous humor and vitreous gel samples.Conclusions Practically all structures of the human eye contain ColXVIII/endostatin, emphasizing its possible important structural and functional role in the human eye. Furthermore, ocular fluid samples contain endostatin fragments, which may contribute to the antiangiogenic properties of the eye.     

糖尿病视网膜病变患者玻璃体中肝细胞生长因子的含量检测

目的 定量研究肝细胞生长因子(hepatocyte growth factor, HGF)在糖尿病视网膜病变(diabetic retinopathy, DR)患者玻璃体中的水平，探讨HGF在增生性糖尿病视网膜病变 (proliferative diabetic retinopathy, PDR)等新生血管形成病理过程中的作用。 方法 采用双夹心酶联免疫吸附测定法检测对照组10只眼玻璃体以及单纯型DR组7只眼、PDR组33只眼和其它与新生血管生成有关的视网膜疾病组8只眼玻璃体切割手术中所取玻璃体内HGF的含量。PDR组中无虹膜新生血管者24只眼，伴虹膜新生血管者9只眼。 结果 玻璃体中HGF的含量对照组为（3.34±1.9）μg/L；单纯型DR组为（4.8±2.5）μg/L；PDR组中不伴虹膜新生血管生成者为（13.0±5.2）μg/L；PDR伴有虹膜新生血管生成者为（18.6±7.2）μg/L，其它与新生血管生成有关的视网膜疾病组为（12.1±8.9）μg/L。PDR组和其它与新生血管生成有关的视网膜疾病组玻璃体中HGF的含量比对照组显著升高(t=6.49, 5.70, 3.01, P<0.01)；PDR组中伴有虹膜新生血管生成者较PDR不伴虹膜新生血管生成者以及单纯型DR组玻璃体中HGF的含量均高，其差异有显著性意义(t=2.47, P<0.05或t=4.84, P<0.01)。 结论 在PDR和与新生血管生成有关的视网膜疾病患眼玻璃体内HGF的含量升高，提示HGF可能在视网膜新生血管生成的病理过程中起一定作用。 (中华眼底病杂志, 2002, 18: 131-13)     

Ocular neovascularization: basic mechanisms and therapeutic advances

The vast majority of diseases that cause catastrophic loss of vision do so as a result of ocular neovascularization. During normal retinal vascular development, vascular endothelial cells proliferate and migrate through the extracellular matrix in response to a variety of cytokines, leading to the formation of new blood vessels in a highly ordered fashion. During abnormal neovascularization of the iris, retina, or choroid, angiogenesis is unregulated and usually results in the formation of dysfunctional blood vessels. When these newly formed vessels leak fluid, hemorrhage, or are associated with fibrous proliferation, retinal edema, retinal/vitreous hemorrhage, or traction retinal detachments may occur resulting in potentially catastrophic loss of vision. In this review, we will briefly discuss the scope of the clinical problem and the general underlying principles of angiogenesis. We will focus on recent laboratory advances that have led to the development of therapeutics useful in the treatment of neovascular eye diseases. We will describe compounds currently in pre-clinical development stages as well as the results of clinical trials involving the use of these drugs as treatments for ocular neovascularization.     

新生血管性青光眼血管内皮生长因子和血小板衍生生长因子含量及其相关影响因素

目的 观察新生血管性青光眼（NVG）患者眼内血管内皮生长因子（VEGF）和血小板衍生生长因子（PDGF）含量,并分析其相关影响因素.方法 实验研究.NVG患者54 例（54眼）,其中视网膜中央静脉阻塞（CRVO）17眼,糖尿病性视网膜病变（DR）22眼,视网膜血管炎（Eales病）4眼,视网膜脱离（RD）术后4眼,未知原因7眼.虹膜新生血管Ⅰ级17眼,Ⅱ级12眼,Ⅲ级13眼,Ⅳ级12眼.36眼曾行视网膜光凝和（或）冷凝治疗.10只新鲜健康角膜供体眼作为正常对照组.抽取两组的房水和玻璃体液样本,采用酶联免疫吸附试验（ELISA）检测其中VEGF和PDGF含量.对NVG组和正常对照组VEGF和PDGF含量的比较采用Mann-Whitney U检验,不同原发病、不同等级虹膜新生血管、视网膜光凝和（或）冷凝治疗组与未治疗组之间VEGF和PDGF含量的比较分别采用方差分析、LsD-t检验和独立样本t检验,并对各组VEGF和PDGF含量进行Pearson相关分析.结果 NVG组房水中VEGF和PDGF含量分别为（926.3±223.5）ng/L和（226.2±81.5）ng/L,玻璃体液中分别为（1096.1±235.9）ng/L和（375.3±141.5）ng/L,均高于正常对照组（Z 房水VECG=-4.993,Z房水PDGF=-4.891,Z玻璃体VEGF=-4.991,Z玻璃体PDGF＝-4.992,P均=0.000）.不同原发病组比较：CRVO组房水和玻璃体液中VEGF含量均高于不明原凶组（t房水=1.746,P房水＝0.033;t玻璃体=1.917,P玻璃体=0.027）,其他各组之间VEGF含量差异均无统计学意义;DR组房水和玻璃体液中PDGF含量高于Eales病组（t房水=1.697,P房水：0.043;t玻璃体=1.762,P玻璃体=0.038）,其他各组间PDGF含量差异均无统计学意义.不同虹膜新牛血管分级组比较：各组房水和玻璃体液中VEGF含量差异均无统计学意义：虹膜新生血管Ⅳ级组玻璃体液中PDGF含量高于Ⅲ级组（t=1.740,P=0.049）.视网膜光凝和（或）冷凝治疗后,房水及玻璃体液中VEGF和PDGF的含量均低于未治疗组（Z房水VEGF＝2.945,P房水VEGF=0.003;t房水PDGF＝3.199,P房水PDGF＝0.002;Z玻璃体VEGF=3.165,P玻璃体VEGF＝002;t玻璃体PDGF＝2.984,P玻璃体PDGF＝0.004）.相关分析显示：NVG组房水中VEGF和PDGF含量呈正相关（r=0.305,P=0.025）,玻璃体液中VEGF和PDGF含量也呈正相关（r=0.303,P＝0.026）;CRVO组玻璃体液中VEGF和PDGF含量呈正相关（r=0.503,P＝0.040）;DR组房水中VEGF和PDGF含量呈正相关（r=0.462,P=0.030）.结论 NVG中VEGF和PDGF含量的变化与其原发病、虹膜新生血管严重程度有关,视网膜光凝和（或）冷凝治疗可抑制VEGF和PDGF的产生.     

Retinal pigment epithelial cells contribute to maturation and fenestration of the vascular endothelial cells in vascular endothelial growth factor-transgenic mice

PURPOSE: To demonstrate the role of the retinal pigment epithelial cells (RPE) in subretinal neovascularization during maturation and fenestration of endothelial cells in vascular endothelial growth factor (VEGF) transgenic mice. METHODS: VEGF transgenic mice were given an intraperitoneal injection of 50 mg/kg of sodium iodate (treated) or physiological saline (controls) on postnatal day 10. Fluorescein angiography (FAG) was carried out and the mice were sacrificed on postnatal day 31. The eyes were removed and processed for light and electron microscopy. RESULTS: FAG showed leakage from neovascularization in both groups, but there were fewer leakages in the treated group than in the control group. Electron microscopy showed subretinal neovascularization in both groups, but there were fewer fenestrations and less maturity of endothelial cells in the new vessels of mice in the treated group. In the treated mice, damaged RPE cells did not completely enclose new vessels and the endothelial cells were immature. CONCLUSIONS: It is suggested that RPE cells promote endothelial cell maturation and formation of fenestrations in VEGF-induced subretinal neovascularization.     

Phthalocyanine photodynamic therapy of experimental iris neovascularization.

Photodynamic therapy using chloroaluminum sulfonated phthalocyanine (CASPc) effectively closed experimental iris neovascularization induced in 6 eyes of cynomolgus monkeys by argon laser retinal vein occlusion. Neovascularization was followed by iris photography, fluorescein angiography, and histopathologic examination by light and electron microscopy. Intravenous injection of CASPc followed by irradiation with 675 nm light damaged endothelial cells and pericytes, leading to exposure of the basal lamina and thrombotic occlusion of the blood vessels. Surrounding tissue appeared preserved without evidence of thermal damage. Resorption of occluded vessels by macrophages began 2 to 3 days after photodynamic therapy. Neovascularization reappeared 7 days after photodynamic therapy, probably representing growth of new vessels. Photodynamic therapy with CASPc may be a useful adjunct in the treatment of iris neovascularization. The model is useful in elucidating the ultrastructural changes observed after photodynamic therapy using phthalocyanines.     

促红细胞生成素受体抗体抑制小鼠视网膜新生血管形成

目的:观察促红细胞生成素受体抗体(erythropoietin recep-tor antibody,EpoRA)对视网膜新生血管形成的抑制作用。方法:将鼠龄为7d的C57BL/6J幼鼠置于750±20mL/L氧仓中连续饲养5d,建立高氧诱导的血管增生性视网膜病变模型。幼鼠20只右眼在建模前1d予以玻璃体内注射EpoRA 2μL作为治疗眼,左眼不注射作为对照眼。在H.E.染色的组织学切片上观察并计数突破视网膜内界膜进入玻璃体的新生血管内皮细胞核数目;用ADP酶组织化学法行视网膜铺片,观察视网膜血管改变。饲养在正常条件下的幼鼠作为正常对照组;模型幼鼠8只仅在玻璃体内注射生理盐水,作为阴性对照组。结果:在组织切片上,可见突破视网膜内界膜进入玻璃体腔内的新生血管内皮细胞核,在用EpoRA注射的右眼,明显少于未经EpoRA注射的左眼(17.20±5.42个vs23.47±8.43个;P<0.01)。ADP酶组织化学法视网膜铺片中,可见视网膜新生血管的密度和异常程度,在用EpoRA注射的右眼,明显轻于未经EpoRA注射的左眼以及阴性对照组。正常对照组未见明显异常。结论:EpoRA可抑制小鼠模型中的视网膜新生血管形成。     

Comparison of lectin reactivity in the vessel beds of the rat eye.

The capillary beds of the eye are lined by two types of endothelia, fenestrated in the choriocapillaris and ciliary body, and continuous in the retina and iris. In this study, we wished to find a marker for each of these types of vessel beds using lectin histochemistry. Sections of glutaraldehyde fixed rat eyes embedded in epoxy resin were extracted with sodium ethoxide and rehydrated. Binding of 15 different lectins was visualized using the avidin-biotin peroxidase technique. We found WGA, WGA-s, LFA and PHA-E to strongly bind retinal vessels. In addition to the above lectins, iris vessels bound GSL-I. Choriocapillaris reacted variably only with WGA and not at all with other lectins tested. Vessels of ciliary body processes did not react with any lectin studied. The less fenestrated vessels of the base of the ciliary process bound lectins similar to the retina. We speculate that the differential lectin staining of the various vessel beds of the eye may reflect the degree of fenestration of the endothelium. This reactivity may be influenced by variations in the surrounding milieu including cells and extracellular matrix.     

Anterior hyaloidal fibrovascular proliferation after diabetic vitrectomy

Vitrectomy was performed to treat 74 consecutive eyes for complications of diabetic retinopathy. Eight (13%) of 61 eyes followed up for an average of 12 months developed anterior hyaloidal fibrovascular proliferation. This was the most common postoperative complication, whose features included recurrent hemorrhages into the vitreous cavity or anterior vitreous, or both; vessels or fibrovascular tissue on the posterior lens capsule; anterior extraretinal vascularization extending toward the lens on the anterior hyaloid; traction detachment of the peripheral retina or ciliary body; and hypotony. Patients who developed this complication tended to be young males with severe retinal neovascularization and extensive retinal ischemia; traction retinal detachment as an indication for surgery; placement of a scleral buckle; postoperative rubeosis iridis, recurrent vitreous hemorrhages, and retinal detachment; and multiple surgeries. Four eyes progressed to atrophia bulbi. Early recognition followed by additional surgery in two patients and extensive additional photocoagulation in two other patients was successful in preserving good visual function.     

增生型糖尿病视网膜病变玻璃体切除手术后再出血病因及治疗

目的 分析增生型糖尿病视网膜病变(PDR)玻璃体切割手术后再出血病因，观察再治疗效果。 方法 回顾分析302例PDR患者315只患眼接受玻璃体切割手术治疗后32只眼再出血并再次治疗后随访3~48个月（平均随访时间12个月）的临床资料。 结果 PDR玻璃体切割手术后再出血发生率为10%，再出血发生时间为手术后1～210 d，平均时间为51 d。再出血的主要原因中，28%为巩膜切口纤维血管向内生长，19%为视盘表面残存新生血管膜或血管残端处理不当，22%为视网膜激光光凝不足，9%为视网膜表面新生血管膜剥除不彻底，6%为视网膜静脉阻塞，16%为外力作用。通过冷凝巩膜切口处纤维血管、剥离视盘和视网膜表面残存新生血管膜并电凝视盘表面血管残端、补充视网膜激光光凝、 包扎双眼等治疗，再出血眼视力提高者占91%，视力下降者占9%。再次手术后并发症主要包括再次出血、虹膜后粘连、晶状体混浊加重、角膜上皮愈合延迟等。 结论 PDR玻璃体切割手术治疗后再出血的主要原因是巩膜切口纤维血管向内生长、视盘表面和（或）视网膜表面新生血管膜剥除不彻底、血管残端处理不当、视网膜激光光凝不足和外力作用。处理好巩膜切口、彻底剥离视盘和视网膜表面新生血管膜、电凝血管残端以及足够的视网膜激光光凝是预防和治疗PDR玻璃体切割手术后再出血的有效方法。(中华眼底病杂志,2007,23:238-240)      

Expression of pigment epithelium-derived factor in normal adult rat eye and experimental choroidal neovascularization

PURPOSE: Pigment epithelium-derived factor (PEDF) is a protein produced by the retinal pigment epithelial (RPE) cells. Recent studies have implicated PEDF in activities that are inhibitory to angiogenesis. In this study, the expression of PEDF was investigated in normal rat eyes and in eyes with experimentally induced choroidal neovascularization and compared with the expression of vascular endothelial growth factor (VEGF). METHODS: Choroidal neovascularization was induced by laser photocoagulation in rat eyes. At intervals of up to 2 weeks after photocoagulation, the eyes were removed and prepared for in situ hybridization and immunohistochemical study. In situ hybridization was performed with digoxigenin-labeled PEDF riboprobes. Protein expression of PEDF and VEGF was studied immunohistochemically. RESULTS: In normal adult rat eyes, PEDF mRNA was observed mainly in the corneal epithelial and endothelial cells, lens epithelial cells, ciliary epithelial cells, retinal ganglion cells, and the RPE cells. During the development of choroidal neovascularization, PEDF mRNA, PEDF protein, and VEGF protein were strongly detected in many cells within the laser lesions at 3 days after photocoagulation, after which levels gradually declined. However, PEDF was still expressed in the RPE cells that proliferated and covered the neovascular tissues at 2 weeks, whereas VEGF protein was weakly expressed in endothelial cells in choroidal neovascularization. CONCLUSIONS: PEDF is expressed in different cell types of normal rat eyes. The expression of PEDF was detected in the choroidal neovascular tissues induced by photocoagulation, and these findings suggest that PEDF may modulate the process of choroidal neovascularization.     

高度近视眼黄斑孔玻璃体视网膜界面的超微结构研究

目的 探讨高度近视眼并发的黄斑孔源性视网膜脱离患者的玻璃体视网膜界面特征。方法 12例高度近视眼黄斑孔视网膜脱离患者，玻璃体切割术中剥离黄斑区内界膜及黏附的玻璃体组织。其中8例标本应用透射电镜观察，4例采用免疫胶体金技术进行层粘连蛋白、纤维连接蛋白标记。2例正常尸体眼作对照。结果 透射电镜显示除l例玻璃体皮质和内界膜部分脱离外，7例标本均发现有成片的玻璃体后皮质粘附于内界膜表面。6例标本发现有上皮样细胞，其胞浆中含色素颗粒，表面有较多足突。免疫电镜显示其界面的层粘连蛋白、纤维连接蛋白数量明显多于正常人（P〈0．001）。结论 高度近视眼并发的黄斑孔源性视网膜脱离患者，黄斑区形成玻璃体劈裂。其视网膜表面膜组织中，以上皮样细胞为主介导胶原纤维的收缩。纤维连接蛋白和层粘连蛋白参与了膜收缩。     

The development of vitreous membranes and retinal detachment induced by intravitreal carbon microparticles

We induced intravitreal cellular proliferation by injection of carbon microparticles (size 20–70 nm) into the vitreous of 21 eyes of 11 cynomolgus monkeys. Pathological changes were evaluated by light and electron microscopy. At 1 week, there was conspicuous cyclitis showing exudative separation of the nonpigmented and pigmented ciliary epithelium, inflammatory cells, mononuclear phagocytes, and premacular vitreous detachment. At 3 weeks, continued macrophagic response was accompanied by fibrovascular proliferation with ingrowth of vessels from the ciliary body into the vitreous. At 4–5 weeks, deposition of extracellular fibrous material and traction retinal detachment (RD) were found. At 10 weeks, all eyes had extensive RD with pre- and subretinal collagenous cellular membranes. Carbon-laden macrophages were aggregated over the optic disc and fovea with prepapillary neovascularization and cystoid macular edema. Thus, intravitreal fibrovascular proliferation, vitreous contraction, and RD were induced by inflammatory and phagocytic response to carbon particles.Presented in part before the Association for Research in Vision and Ophthalmology, Sarasota, Florida, 30 April 1986     

Effect of squalamine on iris neovascularization in monkeys

PURPOSE: To investigate the effect of squalamine, an antiangiogenic aminosterol, in an experimental model of iris neovascularization. METHODS: Iris neovascularization was created in cynomolgus monkeys by occluding retinal veins with an argon laser and inducing persistent hypotony with a central corneal suture. Twenty-four eyes were treated in three groups. In Group 1, four eyes were injected intravitreally with 3 microg/0.1 mL squalamine and four eyes with balanced saline solution (controls) immediately after vein occlusion (day 1); injections were repeated every 3 days for 3 weeks. In Group 2, 1 mg/kg squalamine was administered with intravenous infusion in dextrose 5% in four animals; four control animals received only dextrose. Infusions began on day 1 and were repeated every 3 days for 3 weeks. In Group 3, after development of iris neovascularization on day 7, 1 mg/kg squalamine was injected systemically in four animals; four control animals received dextrose 5%. Monkeys were examined by slit-lamp biomicroscopy and underwent color photography and fluorescein angiography. RESULTS: Group 1: All eyes, treated and control, developed intense and persistent rubeosis iridis. Group 2: Two of the four treated eyes in this group developed minimal iris neovascularization; the other two had no iris neovascularization. All four control eyes developed intense, persistent iris neovascularization. Group 3: All eyes developed extensive rubeosis iridis; iris neovascularization regressed in all four treated eyes after squalamine injections. Two of four treated eyes retained minimal iris neovascularization; two showed complete regression of rubeosis iridis. Rubeosis iridis completely regressed in two of the four control eyes; the remaining two control eyes had intense, persistent iris neovascularization. CONCLUSIONS: Intravitreally injected squalamine did not affect the development of iris neovascularization; however, systemic squalamine injection inhibited the development of iris neovascularization and caused partial regression of new vessels in a primate model.