Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Drainage-retinotomies and relaxing retinectomies are helpful techniques in extreme vitreoretinal surgery. They have become established as a surgical instrument, but their possible pathophysiologic effects on the retina, pigment epithelium and choroid have not been investigated as yet. 30 Patients with retinotomies or retinectomies after vitrectomy with silicone oil filling for advanced proliferative vitreoretinopathy were studied angiographically. Fluorescein angiographic findings revealed 1. a predominant effect of endophotocoagulation in the area of the retinotomy/retinectomy with occlusion of the choriocapillaris and hyperpigmentation and window effects of the retinal pigment epithelium, but sometimes there was a localized traction effect with retinal and choroidal folds, 2. that retinal perfusion is unaffected in untreated and coagulated areas without evidence for a breakdown of the blood-retina-barrier or retinal ischemia, 3. an intact blood-retinal-barrier in areas of uncovered retinal pigment epithelium, 4. no evidence for significant reproliferations in the areas of retinotomies and retinectomies, 5. choroidal neovascular membranes which may occur postoperatively at the retinotomy site probably as a complication for intraoperative injury of Bruch's membrane, 6. a cystoid macular edema, an optic atrophy, pigment-fallout, depigmented tracks and choroidal folds as unspecific findings post retinal detachment surgery. The angiographic data support the clinical impression, that retinotomies and retinectomies performed in otherwise untreatable cases cause no significant damage in the attached retina.
 ...
PMID:[Fluorescein angiography findings after retinotomy and retinectomy]. 175 69

Exudative retinal detachments occur in a variety of retinal and choroidal diseases. We created serous retinal detachment in the cat eye by means of photodynamic injury produced by activation of intravascular rose bengal using filtered, focused light (550 nm). Fluorescein angiography later revealed focal retinal and choroidal vascular occlusion surrounded by a larger area of leakage through the pigment epithelium. Serous retinal detachments occurred rapidly, gradually enlarged over the next 3 days, and resolved in all eyes after 14 to 21 days. Histopathologic and ultrastructural features of early lesions included the accumulation of proteinaceous fluid in the subretinal space, pigment epithelial cell damage, and localized occlusion of retinal vessels and the choriocapillaris. Later changes consisted of limited regeneration of the retina and portions of the tapetum. In several respects, these experimental detachments resemble the serous retinal detachments associated with choroidal ischemia in humans, and may serve as a useful model in the study of choroidal microvascular hypoperfusion.
 ...
PMID:Exudative retinal detachment after photodynamic injury. 198 30

A 51 year-old woman presented with sudden loss of vision secondary to serous neuroretinal detachments of both maculas. Fluorescein angiography revealed multiple hyperfluorescent pin-point dots in the early phases. The areas of fluorescein hyperfluorescence became more diffuse as dye leaked into the subretinal space. The diagnostic of acute monoblastic leukemia was made. Following treatment, her vision improved. Fundus examination at that time showed resolution of the bilateral serous retinal detachment. She died one month after the onset of visual complaints and autopsy was refused. There have been 14 previous reports of acute leukemia with serous retinal detachment. In most cases, retinal detachment occurred as the presenting sign or during relapse of the systemic disease. It was often bilateral and located in the posterior pole. Histopathologic studies showed leukemic infiltration of the choroid with areas of degeneration and proliferation of the retinal pigment epithelium. Angiographic findings are similar to what is observed in choroidal ischemia. The relationships with macular serous retinal detachment and choriocapillaris occlusion are discussed.
 ...
PMID:[Bilateral serous detachment of neuroepithelium of the posterior pole disclosing acute leukemia]. 208 49

The authors show that the variations of intraocular hyper- and hypotension stand for a reserved prognosis in the evolution of the operated retina detachment. Likewise, they consider that the repeated operations in the retina detachment may lead to the syndrome of anterior ischemia, unfavourable to the visual function.
 ...
PMID:[Variable pressure changes (+/-) in the anterior ischemia syndrome--the elements of a reserved prognosis in the surgery of retinal detachment]. 210 Oct 30

Anterior segment ischemia (ASI) is a dreaded complication of retinal detachment surgery particularly in patients with predisposing factors such as sickle cell disease. We report a case of ASI after scleral buckling in an otherwise healthy black patient with sickle cell trait. Conditions of relative hypoxia intraoperatively from either anesthesia or surgical manipulation may precipitate vasoocclusive phenomena in these normally asymptomatic patients. Since the incidence of sickle cell trait in the black population in the United States is 8.5%, we recommend these patients have a preoperative sickle test followed by hemoglobin electrophoresis with quantification if positive. The presence of sickle cell trait should alert the surgeon to the risk of ASI, and factors predisposing to hypoxia should be minimized when possible.
 ...
PMID:Anterior segment ischemia: a complication of retinal detachment repair in a patient with sickle cell trait. 224 89

We describe five eyes of five patients that developed an exudative retinal detachment following a central retinal vein occlusion (including one eye with a hemicentral [hemispheric] retinal vein occlusion). The time interval between the occurrence of the vein occlusion and the appearance of the retinal detachment ranged from 7 to 36 weeks in the four cases seen in the acute period. Each detachment involved the posterior retina and was associated with the development of marked retinal ischemia. Neovascular glaucoma occurred in two cases. The subretinal fluid completely or partially resorbed in the four eyes that were treated with retinal photocoagulation, but the final visual acuity was poor in all cases. Exudative retinal detachment is a potential complication of central retinal vein occlusion and in this series was associated with a poor visual prognosis.
 ...
PMID:Exudative retinal detachment following central and hemicentral retinal vein occlusions. 230 14

Sickle cell retinopathy in its advanced form is complicated by preretinal neovascularization, vitreous hemorrhage, and retinal detachment. Treatment of neovascularization can be performed with photocoagulation. Complications such as retinal breaks, retinal detachments, and choroidally fed neovascularization may result from such treatment. The risks vs. the benefits of various types of photocoagulation are currently being evaluated. Cryotherapy also may be used to treat neovascularization. It is currently being used in eyes with media that are too hazy to permit photocoagulation. It is used commonly during scleral buckling and vitrectomy procedures. In eyes with decreased visual acuity secondary to prolonged vitreous hemorrhage, pars plana vitrectomy can be utilized to produce optically clear media. Complications (including erythrocyte-induced glaucoma), however, may be severe. Retinal detachment can be treated by scleral buckling, but the markedly increased risk of anterior segment ischemia in patients with sickle cell hemoglobin necessitates preoperative, intraoperative, and postoperative prophylactic measures to minimize the risk of this potentially devastating complication. In eyes with retinal detachment with cloudy media and severe vitreous traction, combined scleral buckling and vitrectomy may be necessary. These eyes are extremely fragile, and a successful result is currently obtained in only about 50% of such cases. Hyphemas in patients with sickle cell hemoglobinopathies, whether traumatically or surgically induced, may have devastating effects on the eye. If elevated IOP results decreased vascular perfusion of the eye may cause irreversible damage to the retina and optic nerve. Most antiglaucoma medications, when used in the sickle cell patient, have a narrow margin of safety. Therefore, early surgical intervention for the treatment of sickle cell hyphemas is currently being evaluated.
 ...
PMID:Diagnosis and management of ocular complications of sickle hemoglobinopathies: Part V. 242 44

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.
 ...
PMID:Anterior hyaloidal fibrovascular proliferation after diabetic vitrectomy. 244 1

This report describes a young high-myopic patient who developed rubeosis iridis with peripheral retinal neovascularization one year after a circular buckling operation. Subsequently, vitreous bleeding and exudation led to traction retinal detachment which was treated successfully by anterior vitrectomy and cryopexy. It is suggested that this case represents a mild form of anterior-segment ischemia, combined with peripheral retinal ischemia.
 ...
PMID:Peripheral retinal neovascularization and rubeosis iridis after a bilateral circular buckling operation. 245 62

A gross, light, and electron microscopic study of the eyes from 35 consecutive autopsy cases of the acquired immune deficiency syndrome revealed cotton-wool spots (71% of cases), retinal hemorrhage in areas without cytomegalovirus infection (40%), cytomegalovirus retinitis (34%) with associated retinal detachment, Roth's spots (23%), retinal microaneurysms (20%), papilledema (14%), conjunctival Kaposi's sarcoma (9%), cryptococcal chorioretinitis (6%), Mycobacterium avium-intracellulare in retina and in choroidal granulomas (6%), ischemic maculopathy (6%), bilateral keratitis (3%), and herpes simplex retinitis (3%). Ocular infection with candida or toxoplasmosis were not found in this autopsy series. Immunocytologic studies demonstrated deposition of immunoglobulins in arteriolar walls, consistent with immune complex mediated disease. Ultrastructural studies showed a vasculopathy in the areas near cotton-wool spots. A mechanism is proposed linking the deposition of immune complexes with subsequent small vessel lesions, ischemia, cotton-wool spots and later spread of cytomegalovirus to retina via damaged vascular endothelium.
 ...
PMID:Acquired immune deficiency syndrome. Pathogenic mechanisms of ocular disease. 298 69


<< Previous 1 2 3 4 5 6 7 8 9 Next >>