Effect of pan-retinal photocoagulation in iris neovascularization]

The authors were able to produce experimental rubeosis iridis in the rhesus monkey's eye on 5 days following occlusion of the major retinal vessels and persistent ocular hypotony. Histopathological examination revealed true neovascularization. This experiment attempted to see whether laser pan-retinal photocoagulation plays an inhibiting effect on the occurrence of rubeosis iridis or not. We first performed laser pan-retinal photocoagulation, and at the same time performed occlusion of the major retinal vessels and persistent hypotony to aid for rubeosis iridis. Clinically, rubeosis iridis appeared within 5 days. At 14 days, histological examination revealed vessels on the surface of the iris following pan-retinal photocoagulation treatment were covered by fibroblast and melanocyte, and their endothelial cells showed no fenestrations. This means that clinical rubeosis iridis is not true neovascularization, but dilatation of the iris vessels. Thus, it was confirmed that pan-retinal photocoagulation inhibits development of iris neovascularization.     

Clinical correlation between rubeosis iridis and optic disc neovascularization (author's transl)

Clinical findings and fluorescein angiographies of 293 eyes affected with proliferative diabetic retinopathy were reviewed with the specific aim of looking for a possible correlation between rubeosis iridis and the localization of the new vessels in the ocular fundus. In this series there was a highly significant correlation between rubeosis iridis and optic disc new vessels. Rubeosis iridis was present in 49% of the eyes with optic disc new vessels against only 5.5% of the eyes with retinal new vessels not associated with optic disc new vessels. Among the 97 eyes affected with rubeosis iridis, 91 (93.8%) had also optic disc neovascularization. This clinical correlation allows for predicting which of the eyes affected with proliferative diabetic retinopathy are at a high risk of developing rubeosis iridis. In addition to this, this clinical correlation leads to the hypothesis that there is uveal hypoxia associated to retinal hypoxia in those eyes with rubeosis iridis. Thus iris new vessels may result from uveal hypoxia rather than from retinal hypoxia.     

Neovascularization of the iris: an experimental model in cats

Neovascularization of the iris was induced in cats by removing the vitreous and lens and creating a rhegmatogenous retinal detachment. The presence of new blood vessels on the anterior surface of the iris was verified from the second month onward by slit lamp examination, as well as by light microscopy six to twelve months after the operation. Control eyes undergoing vitrectomy and lensectomy, but without retinal detachment, did not develop rubeosis iridis. This model may allow investigation into causes and therapy of rubeosis iridis.     

Experimental immunogenic rubeosis iridis.

We have developed a primate model of rubeosis iridis in monkeys systemically sensitized to crystalline beef insulin. After intravitreal insulin injection, the dose-related immunogenic inflammation includes cells, flare, fibrin, and blood in the anterior chamber. With more severe inflammation, posterior synechiae, iris bombé, and cataracts occur. Of particular importance, new blood vessels develop within the stroma and on the anterior surface of the iris. Following injection of small amounts of insulin, the anterior surface vessels may regress over time, and the iris regains its normal appearance and coloration. However, the new stromal vessels persist and are cuffed by inflammatory cells including plasma cells. After injection of large amounts of insulin, more extensive structural alterations develop as noted above in conjunction with persistent iris anterior surface and stromal neovascularization. The relationship of rubeosis iridis to clinical inflammatory syndromes and to previous laboratory studies is discussed. Stromal neovascularization was a consistent finding in this experimental model even when anterior surface vessels regressed. On the basis of these experimental data and a review of publications describing human pathology, we believe that a broadening of the classic definition of rubeosis iridis is waranted to include a recognition of the stromal component of the clinical and pathologic findings.     

Irisangiography of rubeosis iridis

In 66 patients with a rubeosis iridis due to diabetes mellitus (25), old central retinal vein occlusion (22), long-standing secondary angle-closure glaucoma (6), total old retinal detachment (3) and chronic uveitis (10), iris angiography was performed. Typical angiographical findings were found in some of the cases. One can differentiate the different modes of formation of the new vessels; angiographically, rubeosis iridis is never a congestion of preexisting vessels but rather an active vascular proliferation which is always permeable to fluorescein.     

The association of rubeosis iridis with endothelialisation of the anterior chamber: report of a clinical case with histopathological review of 16 additional cases.

A patient is reported in whom the clinical observation of extension of the corneal endothelium and Descemet's membrane in association with rubeosis iridis was confirmed by histopathological examination. In a study of eyes which had been removed and demonstrated rubeosis iridis and secondary glaucoma in 16 additional eyes revealed extension of the corneal endothelium and Descemet's membrane on to the anterior iris surface. In all instances the transition occurred at the pseudoangle formed by the attachment of peripheral anterior synechiae. The suggestion is made that the fibrovascular membrane of rubeosis iridis is the stimulus which excites the extension of the endothelium on to the iris surface. The association between rubeosis iridis and extension of the corneal endothelium and Descemet's membrane on to the iris has not been previously appreciated.     

Regression of diabetic rubeosis iridis following successful surgical reattachment of the retina by vitrectomy

The relationship between successful surgical reattachment of the retina following diabetic vitrectomy and regression of preoperative rubeosis iridis was investigated. Seventy-nine (9.2%) of 850 diabetic cases undergoing vitrectomy had both preoperative iris rubeosis and retinal detachment. The iris could be adequately evaluated and the retina could be visualized after surgery in 36 cases. Regression of the rubeosis iridis occurred after surgery in 16 (76%) of 21 eyes in which the retina was reattached successfully. Only four (27%) of 15 eyes had regression of rubeosis iridis when the retina was not reattached completely. Retention of the lens also correlated with regression of rubeosis iridis. Regression occurred in 10 (55%) of 18 cases in which the lens was not removed, 13 (28.2%) of 46 eyes in which lensectomy was combined with vitrectomy, and none of eight previously aphakic eyes. Although the combination of preoperative retinal detachment and rubeosis iridis is associated with a worsened prognosis, successful reattachment of the retina and retention of the lens favorably influence later regression of preoperative rubeosis iridis.     

Indocyanine green iris angiography of lung carcinoma metastatic to the iris

· Background: To investigate the usefulness of indocyanine green (ICG) iris angiography for monitoring vascular abnormalities and the clinical course of metastatic iris tumor during chemotherapy. · Methods: We performed ICG iris angiography at several points during systemic chemotherapy for a 67-year-old man who had been diagnosed as having small-cell carcinoma of the lung with metastatic iris tumors. · Results: ICG iris angiography clearly demonstrated hyperfluorescent tumor vessels, rubeosis iridis, and dilated iris stromal vessels. After chemotherapy, these hyperfluorescent vessels and rubeosis regressed. · Conclusion: ICG iris angiography appears to be an effective and useful method for observing abnormal vessels associated with metastatic iris tumors. Received: 11 May 1998 Revised version received: 30 July 1998 Accepted: 13 August 1998     

荧光素虹膜血管造影联合眼底血管造影在DR合并新生血管性青光眼中的应用

背景 新生血管性青光眼(NVG)是由视网膜缺血缺氧继发的眼病.荧光素虹膜血管造影(IFA)可早期诊断NVG,但其不能全面反映眼底血管情况.IFA联合荧光素眼底血管造影(FFA)可全面检测视网膜及虹膜新生血管情况,但目前国内关于糖尿病视网膜病变(DR)合并NVG患者中此方法的应用研究较少. 目的 探讨IFA联合FFA检查在增生性糖尿病视网膜病变(PDR)患者合并新生血管性青光眼的临床应用.方法 采用回顾性研究方法.纳入2013年2月至2016年1月在河南省立眼科医院接受IFA和FFA联合检查的PDR患者79例133眼,其中无虹膜病变100眼,I期青光眼红变期21眼,Ⅱ期开角型NVG 12眼.所有患眼均行视力、眼压、裂隙灯显微镜、IFA联合FFA检查.采用McNemar非参数检验法对比分析裂隙灯显微镜和IFA检查在I期青光眼红变期患眼检出率的差异. 结果 IFA检查显示100眼无虹膜病变患者无异常虹膜荧光素渗漏,FFA检查显示接受全视网膜激光光凝术(PRP)治疗的32眼未发现视网膜新生血管,68患眼存在视网膜新生血管;早期IFA检查显示,21眼I期青光眼红变期患者瞳孔缘或虹膜表面新生血管荧光素渗漏,FFA检查显示均存在视网膜新生血管;早期IFA检查显示12眼NVG患者虹膜表面新生血管荧光素渗漏,FFA检查显示均存在视网膜新生血管.I期青光眼红变期患眼中IFA检查的检出率为100％(21/21),明显高于裂隙灯显微镜检查的71.43％(15/21),2种检测方法检出率的比较差异有统计学意义(P=0.03). 结论 IFA联合FFA检查可以及早发现PDR合并青光眼红变期,有助于及时指导治疗.     

Preliminary report on effect of retinal panphotocoagulation on rubeosis iridis and neovascular glaucoma.

Eight eyes with central retinal vein occlusion one eye with old central retinal artery occlusion complicated by rubeosis iridis or increased intraocular pressure, or both; and one eye with diabetic retinopathy and rubeosis iridis were treated by retinal panphotocoagulation. Vision did not improve but intraocular pressure was lower and iris neovascularisation regressed in most cases, supporting the hypothesis that retinal hypoxia is a cause of iris neovascularisation and suggesting that retinal panphotocoagulation has a potential prophylactic and therapeutic role in rubeosis iridis and early neovascular glaucoma.     

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.     

Fundus-iris fluorescein angiography: evaluation of its use in the diagnosis of rubeosis iridis

Fundus-iris fluorescein angiography is a technique that allows iris angiography and retinal angiography to be performed simultaneously, using a single injection of dye and a standard retinal fundus camera. We analyzed the ability of this technique to detect rubeosis iridis. In a study of 200 randomly selected angiograms on 400 eyes, the technique was able to detect 97.2% of all eyes with rubeosis iridis (sensitivity), with a false-positive rate of 1%. In 26 eyes (36.6% of all eyes with rubeosis), it was able to detect rubeosis prior to the development of vessels visible by slit-lamp biomicroscopy. The test was able to correctly identify 98.8% of the eyes without rubeosis (specificity), with a false-negative rate of 0.5%. This technique can be performed routinely as part of retinal angiography.     

The myofibroblastic component of rubeosis iridis

Nineteen blind eyes enucleated for painful angle closure-glaucoma secondary to iris neovascularization (rubeosis iridis) were examined by scanning electron microscopy and correlative light and transmission electron microscopy. Fresh and deparaffinized tissue from patients with diabetes mellitus, central retinal vein occlusion, and retinoblastoma were studied. Scanning electron microscopy revealed extensive peripheral anterior synechia formation and flattening and effacement of the anterior iridic surface by a confluent fibrovascular membrane. New vessels on the anterior iris uniformly were hidden beneath a clinically inapparent, superficial layer of myofibroblasts, ie, fibroblastic cells with smooth muscle differentiation. Myofibroblasts may provide the motive force for synechial closure and ectropion iridis in neovascular glaucoma.     

Rubeosis iridis: preoperative iris fluorescein angiography and periocular steroids

To study the risk of developing rubeosis iridis following vitrectomy, the use of preoperative iris fluorescein angiography was prospectively investigated on patients with diabetes mellitus, without any clinically detectable iris or angle neovascularization. With increasing severity of fluorescein leakage, the risk of iris neovascularization with or without glaucoma, six months after vitreous surgery, is significantly increased. It was also determined whether postoperative steroid therapy (periocular triamcinolone acetonide and topical prednisolone phosphate) reduces the risk of developing iris neovascularization after vitrectomy. Controlled and treated patient eyes did not differ significantly in the degree of rubeosis. However, neovascular glaucoma statistically occurred more frequently in the nonsteroid group.     

Circular neovascularization of the circulus arteriosus iridis minor

Vessel duplications of the anastomosis of the cirulus arteriosus iridis minor were observed in 15 patients with diabetes mellitus and in four patients with retinal venous occlusion, in a total of 1192 iris angiograms made. In each of these cases there is a bilateral neo-vascularization that may be regarded as an indication of a general vascular disease. It could be a fairly unaggressive process of new vessel formation in the iris which, during four years of observation, has in none of the cases observed developed into a rubeosis iridis visible under the slit lamp.     

Pinwheel rubeosis iridis following argon laser coreoplasty.

Rubeosis iridis developed in the right eye of a 10-year-old boy with Marfan's syndrome. This eye had a chronic retinal detachment which we could study adequately only after coreoplasty of the iris was carried out with the argon laser. The purpose of this paper is to describe our experience using the argon laser for coreoplasty, and to report the unique pinwheel configuration of the iris neovascularization that developed around the laser lesions. We believe the rubeosis iridis was most likely a sequelae of the chronic retinal detachment, and that the atrophic laser lesions probably acted as templates for the neovascularization, giving rise to its peculiar configuration.     

Rubeosis iridis in "pseudogliomas"

A total of 85 eyes (75 patients) with pseudogliomas (i.e., certain conditions which simulate retinoblastoma, were examined histopathologically to determine the incidence of rubeosis iridis. Neovascularization of the anterior surface of the iris was found in 70 eyes (82%). The principal associated changes in these eyes were moderate to severe inflammation of the uveal tract and retinal detachment. These findings are interpreted as indicating that inflammation, retinal detachment, and/or ischemia are effective stimulants in producing iris neovascularization, and rubeosis is not a significant factor in differentiating eyes with retinoblastoma from those eyes with pseudogliomas.     

Behaviour of the iris vasculature in central retinal vein occlusion: a fluorescein angiographic study of the vascular response of the retina and the iris.

The findings in iris fluorescein angiograms of 48 eyes with central retinal vein occlusion (CRVO) were correlated with the predominant retinal vascular response. In 24 eyes with the non-ischaemic type of CRVO there were no or only minimal iris vessel changes, whereas in all 24 eyes with ischaemic type of CRVO there was iris vessel dilatation and leakage with or without neovascularisation. These findings support the hypothesis that hypoxic retina may be a cause of rubeosis iridis in CRVO.     

Effects of extracapsular cataract extraction with posterior chamber lens implantation on the development of neovascular glaucoma in diabetics

We retrospectively reviewed four cases of extracapsular cataract extraction with implantation of a posterior chamber intraocular lens into diabetics. All four developed postoperative iris rubeosis and neovascular glaucoma; three of the cases had a poor visual outcome. The implant surgeon must show discretion in deciding to implant an intraocular lens in diabetics whether or not they are noninsulin dependent and well controlled, understanding the serious complications that may result from progression of diabetic retinopathy and rubeosis iridis.     

Laser coagulation of the iris surface with neovascularization in glaucoma]

Photocoagulation of the iris surface in the course of rubeosis iridis was performed in 11 patients (12 eyes) with secondary absolute glaucoma. The intraocular pressure was lowered down to 30-35 mm Hg in 8 eyes, in the remaining 4 eyes it oscillated between 45 and 50 mm Hg. The pain receded in all the cases. One considers the possibility that in the disappearance of pain--besides the lowering of the IOP--a substantial factor was the lesion of the innervation of the iris.