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

Combined lensectomy-vitrectomy was performed on 25 eyes in 20 patients with cataracta complicata associated with uveitis from various etiologies. Postoperative follow-up averaged 15 months, with visual improvement in 24 of the 25 eyes. Primary cause of postoperative decreased vision was cystoid macular edema. Operative complications included retinal detachment and choroidal ischemia. The technique employed and the effect of lensectomy-vitrectomy on decreasing the number and severity of recurrent attacks of uveitis are discussed.
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PMID:Uveitis: effect of vitrectomy combined with lensectomy. 23 64

By means of a micro-surgical technique, the central retinal artery of the owl monkey (Aotus trivirgatus) was embolized with spheric plastic beads (7-25 mu in diameter). Beads (4-15 mu) were also injected into choroidal capillaries through a supero-temporal vortex vein. Choroidal ischemia induced proliferation or degerneration of the pigment epithelium, frequently accompanied by photoreceptor degeneration and circumscribed retinal detachment. Occlusion of retinal vessels resulted in posterior vitreous detachment and micro-cystoid degeneration in inner retinal layers, followed by retinal schisis. In combined retinal and choroidal ischemia long-lasting retinal detachments regularly developed.
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PMID:Retinal detachment and pathology following experimental embolization of choroidal and retinal circulation. 82 39

Since the number of cases for each of the conditions in our study was small, only preliminary conclusions can be made; in order to establish the fluorescein pattern of each of these peripheral retinal lesions, additional studies will be required. The following summarizes our preliminary observations. 1. Areas of retinal white-with-pressure or without and peripheral retinal cystoid degeneration did not reveal remarkable fluorescein angiographic findings. One exception was in an area of pigment epithelial disturbance characterized by atrophy and proliferation, which showed a "window and masking" effect of choroidal fluorescence. 2. Fluorescein angiography of areas of the fundus with lattice retinal degeneration showed little or no findings in early or mild cases. In severe or advanced cases, the affected retina revealed poor or absent perfusion caused by vascular occlusion. The retinal and choroidal circulation was devoid of fluorescein leakage. Advanced lesions displayed choroidal hypofluorescence in areas of pigment proliferation and hyperfluorescence in areas of pigment atrophy. 3. In advanced cases, occlusive vascular changes over areas of acquired retinoschisis were observed. There was intraretinal leakage of the dye from deep capillaries and pooling of the dye in cystic cavities near the margin of the retinoschisis. 4. There was no perfusion of the choroid and retina in the area of the hole and in the retina surrounding it. This finding suggests choroidal and retinal ischemia in the pathogenesis of a retinal hole. 5. Fluorescein angiography of retinal tears revealed fluorescein leakage along the edge of the tear and absent perfusion of the retinal flap. The retinal and choroidal circulation-around the tear was otherwise unremarkable. The choroidal fluorescein underlying the retinal flap was not visible, perhaps because it was masked by the retinal flap. 6. Our fluorescein angiographic findings in cases of rhegmatogenous retinal detachment confirmed those of others [7, 8, 10]. Transit of fluorescein through the retinal circulation was sluggish. The retinal capillaries were dilated. 7. In cases of rhegmatogenous retinal detachment which had become reattached surgically, areas treated with diathermy or cryoapplications showed absent or diminished choroidal and retinal perfusion. Leakage of the fluorescein from capillaries in the optic disc and retina in the posterior pole was sometimes persistent several months postoperatively.
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PMID:Fluorescein angiography of degenerative lesions of the peripheral fundus and rhegmatogenous retinal detachment. 93 73

In diabetic patients with massive vitreous hemorrhage, fluorescein angiography after pars plana vitrectomy demonstrated varying degrees of vascular involvement depending on the stage of the basic disease process. Arteriolar occlusions, capillary bed drop-out, microaneurysms, and neovascularization were common findings. We concluded that diabetic retinopathy continued its course behind the cloudy vitreous, sometimes leading to retinal ischemia and subsequent spontaneous involution, macular disease, or retinal detachment. In addition, some of these patients were also subject to nondiabetic diseases, such as senile macular degeneration, that could not be detected preoperatively, but that reduced visual acuity postoperatively. In the nondiabetic patients with vitreous hemorrhage, visual acuity after vitrectomy usually depended on the degree of coincident macular disease.
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PMID:Fluorescein angiography of the fundus after pars plana vitrectomy. 96 56

A 69-year-old woman with chronic lymphocytic leukemia developed segmental iris atrophy and iridocyclitis after routine surgery for exotropia. Both the clinical picture and fluorescein angiogram indicated anterior segment ischemia. It is postulated that this was related to hyperviscosity of the blood caused by a high white blood cell count (114,000/cu mm). The possibility of anterior segment ischemia should be kept in mind when contemplating strabismus or retinal detachment surgery in the presence of hematologic disorders likely to increase blood viscosity. In these cases a minimal amount of surgery should be done with proper supportive therapy. Strabismus surgery should be done in stages allowing for hemodynamic compensation between procedures.
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PMID:Anterior segment ischemia and sector iris atrophy: after strabismus surgery in a patient with chronic lymphocytic leukemia. 103 46

A 63-year-old man with a one-quadrant retinal detachment developed anterior segment ischemia after an operation that included the use of cryopexy, release of subretinal fluid, and segmental episcleral buckling without detachment of the extraocular muscles. A compromised cardiovascular condition of long duration and an episode of transient hypotension immediately preceding operation were factors in the pathogenesis of the ischemia. Although the anterior segment changes were moderately severe, recovery of vision ultimately was excellent.
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PMID:Anterior segment ischemia after segmental episcleral buckling and cryopexy. 114 49

The natural course of Branch Retinal Vein Occlusion is determined by the site and completeness of the occlusion, the integrity of arterial perfusion to the affected sector and the efficiency of the developing collateral circulation. Most patients with tributary vein occlusion have some capillary fall out and microvascular incompetence in the distribution of the affected retina and vision is significantly compromised in over 50% of patients who have either chronic macular oedema or ischemia involving the perifoveolar arcades. Retinal and capillary vasoproliferation with or without intraretinal or preretinal membrane formation are common sequelae, where inner retinal ischemia is extensive and vitreous hemorrhage is often a distinct threat to vision. Treatment of the sequelae of vein occlusion are largely centered on laser photocoagulation to diseased retina to limit fluid accumulation and abolish preretinal and papillary neovascularization. Vitrectomy and retinal detachment procedures are occasionally required in patients with uncontrolled vitreous hemorrhage and retinal membrane formation which threatens the integrity of the macula. A small proportion of patients with vein occlusion subsequent to vasculitis require medical therapy.
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PMID:Branch retinal vein occlusion and its management. 128 82

Between January 1986 and December 1989 we prospectively studied 125 patients with central retinal vein occlusion (CRVO). Documented by fundus photography and fluorescein angiography clinical and angiographic findings were analysed. The age of the patients was between 22 and 89 years with a mean of 60 years. 74 (59%) were male and 51 (41%) female. 63 (50.4%) right and 62 (49.6%) left eyes were affected. Arterial hypertension was found in 34 (37.2%) and diabetes mellitus in 18 (14.4%) of the patients. Glaucoma was present in 14 (11.2%). 11 (8.8%) patients had bilateral CRVO. Preretinal neovascularisation was found in 5 (4%), vitreous hemorrhage in 6 (4.8%) and a retinal detachment in 2 (1.6%) patients. Iris neovascularisation at time of first presentation was found in 8 (6.4%) of all patients, related to the number of ischemic type of CRVO in 17.7%. Cystoid macular edema was found in 77 (61.6%), ischemic maculopathy in 24 (19.2%) patients, and a combination of cystoid and ischemic maculopathy in 11 (8.8%). Mean visual acuity was 20/100. A non ischemic type was present in 80 (64%) an ischemic in 45 (36%) of patients. Mean visual acuity in the non ischemic type was 20/60 and highly significant better (p < 0.0001) than in the ischemic type with a mean visual acuity of 20/400 (Mann-Whitney test). The density of intraretinal hemorrhages (p = 0.0005) and type of maculopathy (p < 0.0001) were highly significant related to the ischemia type (chi-square method).
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PMID:[Clinical and fluorescein angiography changes in patients with central retinal vein occlusion. A unicenter study of 125 patients]. 147 86

Experimental chorioretinopathy was induced by injecting 0.1% adrenalin intravenously in pigmented rabbit eyes. The fundus of each eye was analyzed with ophthalmoscopy and fluorescein fundus angiography (FFA). Histopathological sections were examined from each of following areas: (a) those with serous retinal detachment and evidence of dye leakage on FFA, (b) those with serous retinal detachment, but no dye leakage on FFA, and (c) those without detachment. In areas with serous detachment and dye leakage on FFA, the choroidal arterioles showed irregularly narrowed cavities, and the lumens of the choriocapillaris were remarkably narrowed. Most of the choroidal venules were enlarged and filled with many blood cells. Some had wide openings in the endothelial intercellular spaces, resulting in leakage of blood components into suprachoroidal space. Bruch's membrane was hypertrophic and some of overlying retinal pigment epithelium (RPE) had disappeared. The residual RPE showed degenerative changes, such as intracellular vacuole formation. Both in areas with detachment but no dye leakage on FFA, and in areas without detachment, similar but milder pathological changes were observed in choroidal arteriole and choriocapillaris. Severe damage, such as RPE defects and wide openings of endothelial intercellular spaces in choroidal venule, were not observed. These results suggest that intravenous adrenalin may affect choroidal venules as well as the choroidal arterioles and choriocapillaris in rabbit eyes, resulting in wide openings of their endothelial intercellular spaces. These histopathological change may lead to RPE damage by the choroidal ischemia and the leakage of blood components, leading to the induction of experimental chorioretinopathy.
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PMID:[Histopathologic study of experimental chorioretinopathy induced in pigmented rabbits by intravenous adrenalin injection]. 155 77

A 22-year-old man with Eales' disease with secondary rhegmatogenous retinal detachment with a break five disc diameters from the disc underwent radial scleral buckling using a silicone sponge episcleral explant with local cryopexy. Five hours after surgery the patient had no light perception. There was no intraoperative or postoperative rise of intraocular pressure or central retinal artery ischemia. Immediate removal of the explant brought a return of light perception and postoperative visual acuity improvement. The episcleral explant may have caused the direct optic nerve trauma that resulted in loss of vision.
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PMID:Sudden vision loss following retinal detachment surgery. 157 71


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