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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Surgery for diabetic retinopathy addresses late secondary complications of a primary microvascular disease. Since surgery is not a causative therapy, the functional outcome of surgery depends on the degree of retinal ischemia and may be disappointing even in technically and anatomically successfully operated eyes. Typical indications for vitrectomy are vitreous hemorrhage, tractional retinal detachment, combined tractional rhegmatogenous retinal detachment and tractive macular edema. More recently diffuse diabetic macular edema has been shown to improve after removal of an attached vitreous in several cases. Neovascular glaucoma requires aggressive surgical intervention to salvage the eye. Cataract surgery is commonly performed in eyes with diabetic retinopathy. It may however deteriorate diabetic eye disease. Vitreous surgery also has a potential for severe complications in diabetic eyes which can be ameliorated but not eliminated by proper surgical strategies and techniques. The decision for an intervention in diabetic eyes always requires a careful weighing of risks and benefits of surgery.
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PMID:Surgery for diabetic retinopathy. 1738 64

Ocular vascular diseases such as diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration, whose population increases along with aging, have become leading causes of severe visual disturbance. Macular edema and serous retinal detachment are associated with abnormal vascular leakage and tractional retinal detachment, and neovascular glaucoma is caused by retinal neovascularization. Such ocular vascular diseases are caused by vascular cell aging and vascular damage associated with lifestyle-related diseases including diabetes mellitus, hypertension, hyperlipidemia, and obesity. In the present study, we investigated molecular mechanisms in such vascular deficiencies using vascular cell biology methodology, and we propose novel strategies for the treatment of such vascular diseases. Along with aging, oxidative stress and physical stress, such as mechanical stretch, continuously and directly insult vascular cells. Such stress induces apoptosis by intracellular signaling through stress kinases in cultured retinal vascular cells. Inhibition of such stress kinases could be an effective treatment to protect the vascular cells against age-related damage. In a retinal vascular developmental model, pericyte loss causes pathology mimicking macular edema and proliferative diabetic retinopathy. Angiopoietin 1 (Ang 1) secreted by pericytes suppresses oxidative stress-induced intracellular signaling through stress kinases linked to cell apoptosis and normalizes such retinal pathology. This suggests that the paracrine action of Ang 1 in the pericytes is necessary to sustain normal retinal vasculature, and that Ang 1-triggered intracellular signaling is useful for the treatment of vascular cell pathology associated with pericyte loss. In diabetic retinopathy and retinal vein occlusion, retinal vessels regress along with retinal vascular cell apoptosis, and the retina becomes ischemic followed by pathological retinal neovascularization. VEGF has been recognized as a predominant factor to induce the ischemic retinal neovascularization. We found that retinal vascular cells have a characteristic pattern in VEGF receptor expression, which causes vascular pathology more frequently in the retina than in other organs. Neuropilin 1 (NRP 1), which enhances VEGF receptor function, is abundantly expressed in the retinal endothelial cells and is upregulated by VEGF itself and by hypoxia to regulate a positive feedback mechanism in retinal neovascularization. This receptor could be a unique target for retina-specific therapy. Lifestyle-related diseases increase along with aging and have further increased due to changes in Japanese lifestyle imitating that of Western countries. We found that the renin-angiotensin system which regulates hypertension and cardiovascular diseases, and adipocytokines which are abnormally secreted in obesity, act as proangiogenic factors. Regulation of such lifestyle-related disease factors is important for the treatment of retinal vascular diseases. Finally, we found that erythropoietin is an ischemia-induced angiogenic factor that acts independently and as potently as VEGF in proliferative diabetic retinopathy (PDR). Our study utilizing human vitreous samples demonstrates that the VEGF level is particularly high and strongly associated with angiogenic activity in PDR patients. The potential of VEGF inhibitors has recently been recognized in clinical applications. The manipulation of each angiogenic factor and adipocytokine that we report here could become potential therapy in the near future.
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PMID:[Aging and retinal vascular diseases]. 1740 63

Neovascular glaucoma (NVG) is a severe form of glaucoma with devastating visual outcome attributed to new blood vessels obstructing aqueous humor outflow, usually secondary to widespread posterior segment ischemia. Invasion of the anterior chamber by a fibrovascular membrane initially obstructs aqueous outflow in an open-angle fashion and later contracts to produce secondary synechial angle-closure glaucoma. The full blown picture of NVG is characterized by iris neovascularization, a closed anterior chamber angle, and extremely high intraocular pressure (IOP) with severe ocular pain and usually poor vision.
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PMID:Neovascular glaucoma: etiology, diagnosis and prognosis. 1937 96

Central retinal vein occlusion (CRVO) is one of the common causes of visual loss. The main reasons for decreased vision are development of macular edema, macular ischemia and neovascular glaucoma. The introduction of anti-vascular endothelial growth factor (VEGF) drugs for CRVO in 2005 demonstrated marked improvement in visual acuity, macular edema and ocular neovascularization. However, the absence of clear guidelines for the treatment of CRVO presents a genuine therapeutic challenge. In a national study conducted among the Israeli society of retinal specialists (personal communication), it was found that most of these specialists would recommend intravitreal anti-VEGF drug injection immediately upon the diagnosis of macular edema in non-ischemic CRVO with visual acuity of 6/15 or less. Only 21% would recommend this treatment in ischemic CRVO with visual acuity of 6/60 or less, if no macular edema exists. After the edema resolves, 94% would follow-up the patients by imaging with optical coherent tomography every 4-6 weeks, and recommend further treatment accordingly. Large prospective controlled studies are warranted in order to address the important issues of when to start anti-VEGF treatment for CRVO, when to withhold treatment, and recommended treatment intervals.
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PMID:[The use of anti-angiogenic drugs for central retinal vein occlusion]. 2081 99

Central retinal vein occlusion (CRVO) remains one of the most common retinal vascular disorders that may lead to blindness. The etiology is unknown, however, predisposing factors such as hypertension, diabetes, atherosclerosis and hypercoagulable states have all been described. Local ophthalmic illnesses such as open angle glaucoma, ocular trauma and orbital infections have also been suggested as causative. CRVO can be subdivided into two clinical types, ischemic and non-ischemic. The non-ischemic type comprises the milder form of the disease with partial venous obstruction and good visual outcome. Ischemic CRVO is the severe form and is associated with visual loss, because of nearly total retinal vein obstruction and poor perfusion to retina. In addition, patients with ischemic CRVO may end up with additional complications such as neovascular glaucoma that may lead to blindness. Over 90% of CRVO occurs in patients > 65 years. The presenting symptom is a sudden painless mono-ocular decrease in visual acuity which could result from macular edema, ischemia, or intraocular bleeding. Ophthalmoscopic examination reveals macular edema, retinal bleeding (more peripheral), tortuous vein dilatation and swollen disc. Current treatment modalities include systemic use of anticoagulation drugs, local treatments including laser, intravitreal injection of anti-vascular endothelial growth factor and surgery (vitrectomy). This review presents the current therapeutic modalities in CRVO.
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PMID:[Treatment modalities in central retinal vein occlusion]. 2081

A 12-year-old girl with neurofibromatosis type 1 was referred for pain and blurred vision in her right eye for the past 2 weeks. Neovascular glaucoma associated with peripheral retinal ischemia was diagnosed and she was treated with retinal photocoagulation after intravitreal bevacizumab injection and trabeculectomy.
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PMID:Unusual association of peripheral retinal ischemia-induced neovascular glaucoma and neurofibromatosis type 1. 2121 63

Interferon (INF)-associated retinopathy occurs in 15-64% of INF-treated patients, transforming this complication into a significant risk for visual impairment. This retinopathy has been described as an ocular complication with a variable clinical course, usually benign and asymptomatic. The most common findings are hemorrhages and cotton wool spots. Atypical ocular side effects include branch or central retinal artery occlusion, central retinal vein occlusion, anterior ischemic optic neuropathy, optic disc edema, neovascular glaucoma and vitreous hemorrhage. Some case series suggest that in most cases the clinical course of the disease is benign, asymptomatic and without long-term consequences and therefore do not recommend any specific treatment; they only recommend the discontinuation of INF in patients with severe manifestations or risk factors such as hypertension or diabetes mellitus. The case reported here presents an atypical manifestation of INF-associated retinopathy consisting of a mixed retinal vascular occlusion (arterial and venous), associated with severe occlusive inflammatory microangiopathy with extensive retinal damage by ischemia and a torpid clinical course despite suspension of treatment. These varieties of occlusive vascular events have not yet been found simultaneously in the literature and neither with an unfavorable clinical course. Although the clinical course of INF-associated retinopathy in most cases is asymptomatic, there may be complications with risk to vision, which is less common. The magnitude and severity of the consequences associated with INF therapy are to be determined in prospective further studies.
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PMID:Mixed vascular occlusion in a patient with interferon-associated retinopathy. 2132 40

Neovascular glaucoma is defined as an iris and/or anterior chamber angle neovascularization associated with increased intraocular presure. It is a secondary glaucoma most frequently determined by a severe retinal ischemia. The most common diseases responsible for the development of neovascular glaucoma are diabetic retinopathy, ischemic central retinal vein occlusion and ocular ischemic syndrome; the uncommon causes include ocular radiation, ocular tumors, uveitis and other miscellaneous conditions. Vascular endothelial growth factor is an important and probably predominant agent in the pathogenesis of both intraocular neovascularization and neovascular glaucoma. The evolution of clinical and histopathological changes from predisposing conditions to the occurrence of rubeosis iridis as well as neovacular glaucoma is divided into four grades that is prerubeotic, preglaucomatous, open-angle and angle closure glaucoma stages.
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PMID:[Neovascular glaucoma--etipathogeny and diagnosis]. 2342 56

Neovascular glaucoma management is divided into preventive and curative procedures.Pre vention therapy consists of the treatment of the common underlying causes of the disease (ie diabetic retinopathy, ischemic central retinal vein occlusion and ocular ischemic syndrome) as well as the less frequent causes attributed to ocular radiation, ocular tumors, uveitis and other miscellaneous condi tions.Curative therapy includes both the neovascularization treatment and the treatment of the in creased intraocular pressure.lntravitreal Bevacizumab injection enables us to block up the neovascular trigger preparing thereby the pacient to a complement of panretinal photocoagulation or surgical treatment. Since Bevacizumab injection activity is transient, the retinal ischemia treatment by panretinal photocoagulation is mandeited in order to avoid neovascular recurrence.Short term efficacy of Bevacizumab injection is obvious with a constant, marked and swift intraocular pressure lowering espe cially in less severe and/or early forms of the disorder. In more advanced stages of neovascular glaucoma after closing the chamber angle by peripheric anterior synechiae the outcomes of this treatment are inconstant, most of cases necessitating the resorting to surgery (trabeculectomy with antifi brosis drugs or glaucoma drainage implants).
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PMID:[Treatment of neovascular glaucoma]. 2371 36

A 64-year-old man with a long history of untreated diabetes mellitus had suffered from visual disturbance in his right eye. Neovascular glaucoma in the right eye and diabetic retinopathy in both eyes were found, and ischemic ocular syndrome was suspected for the right eye. Neuroimaging revealed severe stenosis of the right internal carotid artery. He was first treated for diabetes and glaucoma, and then, after these conditions were stabilized, right carotid endarterectomy (CEA) was carried out. Although the operation was uneventful, he suffered from headache and his right sight was blurred on the day after surgery. Right intraocular pressure was markedly increased, and corneal edema and increased iris neovascularization were also recognized. Intensive ophthalmologic care was carried out, but his right vision worsened and was eventually lost. Ocular ischemia causes not only neovascularization of the iris, which leads to insufficient resorption of the aqueous humor, but also insufficient production of the aqueous humor. After CEA, production of the humor is immediately activated, but the resorption capacity does not change, which results in an extraordinary increase in intraocular pressure. Neurosurgeons should be aware that CEA not only improves or avoids worsening of vision in patients with ischemic oculopathy, but can also rarely cause paradoxical devastating visual deterioration.
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PMID:Deterioration of glaucoma after carotid endarterectomy. 2380 21


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