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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sickle cell retinopathy, in all of its manifestations, represents the effects of arteriolar and capillary occlusions. Increased viscosity of circulating whole blood plus the microembolic action of individual sickled erythrocytes contribute to vasoocclusion. Decreased oxygenation and increased acidosis develop and lead to further sickling -- and further vaso-occlusion. The cycle of erythrostasis that characterizes sickling throughout the body is also applicable to the retina. The transparent media of the eye permit direct visualization of vaso-occlusions which occur preferentially in and about the macula and in the far periphery of the retina. Many of the occlusive episodes are transient. There dynamic events are simultaneously occurring elsewhere in the body but can only be visualized in the eye. The net effect in the retina is a remodeling of its vasculature, as some vessels close and others reopen. After the onset of arteriolar closure in the retina, affected blood vessels embark on a spontaneous, naturally evolving course of events leading to arteriolarvenular anastomoses, neovascular proliferations, vitreous hemorrhages, and retinal detachment. The advanced stages of proliferative sickle retinopathy are most commonly observed in SC disease and in Sthal, possibly because these two forms of sickling have significantly higher than normal whole blood viscosity. Retinal vaso-occlusions can also lead to blow-out hemorrhages which may evolve into salmon patches, iridescent spots, schisis cavities, and black sunbursts. In some respects sickle retinopathy is unique, but many of its manifestations are similar to those of retinopathies found in diabetes mellitus, AC hemoglobinopathy, Takayasu pulseless disease, sarcoidosis, chronic myelogenous leukemia, branch retinal vein occlusion, retrolental fibroplasia, and Eales disease.
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PMID:Retinal vaso-occlusion in sickling hemoglobinopathies. 78 1

During 15 months all the patients with retinal or vitreous hemorrhages diagnosed in departments of ophthalmology or internal medicine in Bamako (Mali) were submitted to an aetiological assessment. Only patients with hemorrhages caused by a general aetiology were included in the study. 64 cases were selected according to these criteria. Hemoglobinopathies were involved in 14.1% of cases, high blood pressure in 31.8%, diabetes mellitus in 10.9% and miscellaneous causes in 15.6%. In 26.6% of cases an association between several of these aetiologies was observed. SC hemoglobin was the most frequent and the most serious. AS and AC traits were involved in 2 retinal hemorrhages' cases. AS and AC traits' responsibility in ocular hemorrhages associated with diabetes mellitus or high blood pressure was doubtful. A frequent association of sickle cell trait and high blood pressure was noticed. One case of Eales syndrome is reported during a diabetes mellitus-AS trait. All the patients were submitted to a treatment by pentoxifylline. Moreover 5 patients were treated by a laser coagulation and 2 patients by cryoapplication. The interest of the hemoglobin electrophoresis for the aetiologic assessment of retinal and vitreous hemorrhages is stressed.
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PMID:[Retino-vitreous hemorrhage in hemoglobinopathies]. 177 9

Sixty four cases of retinal and vitreous hemorrhages are reported during a 15 months prospective study in Bamako. Main diseases associated with hemorrhages are high blood pressure (56% of cases), hemoglobinopathies (33%) and diabetes mellitus (23%). In 28% of cases several aetiologies are connected. SC hemoglobin is a frequent aetiology of vitreous hemorrhage (40%). Hemoglobin AS and AC, generally asymptomatic, are also liable to hemorrhages. Terson and Eales syndromes, Werlhof disease, hemophilia and AIDS are most uncommon. In 8% of cases there is not any aetiology.
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PMID:[General causes of retinal and vitreous hemorrhages in Mali]. 181 88