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

A combination of various electrophysiologic tests--simultaneous recording of VER and ERG, EER, and single-flash ERG--is proposed to assess visual function in eyes being considered for vitrectomy. To establish the validity of the method, eyes of normal subjects and of some patients with clear media and types of ocular pathology often associated with opaque vitreous were tested. A higher stimulus threshold for VER than for ERG recorded simultaneously can be used to diagnose severe optic atrophy in eyes with opaque media. EER reflected the status of the retinal circulation and the function of the optic nerve, rather than the extent of the tractional retinal detachment in diabetic retinopathy. As electrical stimulation to the retina is little affected by opaque media, the EER can be a useful test in massive vitreous hemorrhage, diabetic retinopathy, and rhegmatogenous retinal detachment. Single-flash ERG was compared with ERG recorded with the response-summation technique. The b/a wave amplitude ratio in single-flash ERG was useful in assessing the middle layer of the retina in opaque media, whereas the latter technique, though useful when recorded simultaneously with VER, distorts the shape of the responses in such a way as to simulate the findings in retinal ischemia.
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PMID:Electrophysiologic testing of visual functions for vitrectomy candidates. I. Results in eyes with known fundus diseases. 687 4

Eighteen patients (19 eyes) with sickling hemoglobinopathies underwent vitrectomy or scleral buckling operations. The indications for surgery were tractional or rhegmatogenous retinal detachment or vitreous hemorrhage. The retina was reattached in all four patients with rhegmatogenous detachments requiring scleral buckling surgery but no vitrectomy. All had excellent visual acuity postoperatively. Four of the five patients with vitreous hemorrhage requiring vitrectomy without buckling had substantial improvement in visual acuity. In ten patients with vitreous hemorrhage with either preexisting or iatrogenic retinal breaks, rhegmatogenous detachment, or tractional detachment, the rate of improvement in visual acuity was only 50%. Problems associated with vitreous or retinal surgery in patients with sickling hemoglobinopathies include iatrogenic retinal breaks, intraocular bleeding and secondary glaucoma, anterior segment ischemia, and systemic sickling.
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PMID:An update on vitrectomy surgery and retinal detachment repair in sickle cell disease. 707 71

Nine patients, seven women and two men, ranging in age from 21 to 86 years, had generalized vascular disease and significant deficits in choroidal perfusion but no retinal vascular changes. Because these perfusion abnormalities can be identified only by fluorescein angiography and the fundus appears to be normal, choroidal ischemia may be more common than has been realized. Infarction of the choroid, retinal pigment epithelium, and outer retina are usually unassociated with retinal detachment; even ischemia severe enough to induce retinal detachment seldom produces significant atrophy.
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PMID:Choroidal ischemia. 713 73

Retinal detachment is a rare complication of preeclampsia, eclampsia and abruptio placentae. We report a case of bilateral retinal detachment in association with severe preeclampsia complicated with abruptio placentae, intrauterine fetal death and disseminated intravascular coagulation. In obstetric complications, placental thromboplastin may release into maternal circulation and activate the extrinsic coagulation system with resultant disseminated intravascular coagulation. This may be responsible for choroidal ischemia and consequent serous retinal detachment.
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PMID:Retinal detachment in association with preeclampsia and abruptio placentae. 763 40

Pars plana vitrectomy (PPV) with silicone oil implantation (SOI) was performed for advanced proliferative diabetic retinopathy (PDR) in 110 eyes of 98 diabetic patients. In 77 eyes (70%) it was a primary SOI as part of the initial operation; in 33 eyes (30%) it was a secondary SOI in reoperations. Indications for SOI were traction retinal detachment of the posterior pole, combined traction and rhegmatogenous detachment, vitreous haemorrhage with florid vascularised fibrous proliferations, and recurrent vitreous haemorrhage after PPV. The patients were followed up for 24 to 72 months, with a mean of 53 months. At the end of follow-up, anatomical success was achieved in 63 eyes (57%), and functional success with visual acuity 0.01 and better in 35 eyes (32%). Functional failures were caused by retinal redetachment in 47 eyes (43%), by secondary glaucoma in 10 eyes (9%), retinal ischemia in 15 eyes (13%) and keratopathy in three eyes (3%). The functional success rate decreased with follow-up from 67% after six months to 50% by 60 months after SOI. Silicone oil bubble in the anterior chamber, rubeosis iridis, cataract, and glaucoma were the most frequent postoperative complications. PPV with SOI was highly effective in many serious complications of advanced PDR. Functional success was mostly lasting and markedly improved the quality of life of these patients.
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PMID:Long-term results of pars plana vitrectomy and silicone oil for complications of diabetic retinopathy. 801 22

Anterior migration of an encircling element through a rectus muscle is an unusual complication of scleral buckling surgery. We describe two patients with migration of a solid silicone encircling element through the insertions of all four rectus muscles after retinal detachment surgery. Buckle migration was associated with elevated intraocular pressure and glaucomatous optic atrophy. Rectus muscle function was preserved in both patients. Despite transsection of the anterior ciliary blood supply, anterior segment ischemia did not develop.
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PMID:Migration of solid silicone encircling element through four rectus muscles. 823 34

Macular complications occurred in two isolated patients who had pericentral pigmentary retinopathy. One patient demonstrated bilateral bull's-eye maculopathy and a unilateral full-thickness macular hole. Later, she developed central retinal artery occlusion in the fellow eye. The second patient had a rhegmatogenous retinal detachment that was reattached by scleral buckling surgery, but a full-thickness macular hole was found 3 months postoperatively. In both patients, foveal ischemia may have played a role for the development of macular hole, resulting in poor visual prognosis in pericentral pigmentary retinopathy.
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PMID:Associated ocular findings in pericentral pigmentary retinopathy. 908 14

The authors describe the rare complication of hypopyon uveitis following panretinal photocoagulation. A 55-year-old man with a history of diabetes mellitus and previous repair of a retinal detachment by scleral buckle and vitrectomy was referred to the authors after a hypopyon uveitis developed following supplemental panretinal photocoagulation. The patient was treated with frequent topical steroids in addition to periocular injection of steroids with resolution of the inflammation. Risk factors for anterior segment ischemia, such as a history of a scleral buckle, may predispose diabetic patients to the complication of hypopyon uveitis following panretinal photocoagulation.
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PMID:Hypopyon uveitis following panretinal photocoagulation. 918 55

Eleven patients with rapidly progressive herpetic retinal necrosis (RPHRN) complicating AIDS were investigated retrospectively to study the disease spectrum, systemic involvement, and therapy. The mean CD4 cell count was 24/microL. There was a characteristic disease pattern with rapid progression, 82% bilaterality, relative resistance to intravenous antiviral therapy, and 70% retinal detachment. Varicella-zoster virus was the probable cause in 10 patients (detected by polymerase chain reaction in two eyes investigated), and herpes simplex virus was the probable cause in one. Cutaneous zoster occurred previously in 73% but was not concurrent. Seventy-three percent had central nervous system disease, possibly virus-related. RPHRN may be a local herpetic recrudescence in an immune-privileged site with transneural spread. Only four of 20 affected eyes retained useful vision. Poor ocular bioavailability, retinal ischemia, acquired drug resistance, and strain pathogenicity may underlie treatment failure. Acyclovir therapy appears relatively ineffective. Combined intravenous and intravitreal therapy with foscarnet and ganciclovir may be the best current management. Research advances are needed urgently.
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PMID:Rapidly progressive herpetic retinal necrosis: a blinding disease characteristic of advanced AIDS. 945 7

Sickle cell eye disease is characterized by microvascular occlusion that affects the peripheral retinal vasculature and results in retinal ischemia and the development of proliferative sickle cell retinopathy. Complications of proliferative sickle cell retinopathy such as vitreous hemorrhage and retinal detachment are the most common causes of visual loss in this disease. Prevention of this visual loss is therefore contingent on the prevention or early detection and treatment of proliferative sickle cell retinopathy. Most effort has been directed toward therapy for established proliferative sickle cell retinopathy, and several therapeutic trials have been reported. Much less is known about the risk factors for development of proliferative sickle cell retinopathy and its natural history, in particular the true incidence of permanent visual loss. Visual loss is believed to be predominantly a complication of perfused proliferative sickle cell retinopathy, and its autoinfarction renders such visual loss less likely. To better define the place of treatment, identification of the determinants of autoinfarction is required, but identification of patients whose proliferative sickle cell retinopathy is likely to proceed to visual loss is of greater importance.
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PMID:Recent advances in the treatment of proliferative sickle cell retinopathy. 1014 2


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