Showing papers on "Retinal Vein published in 1981"

Central retinal vein occlusion: a prospective histopathologic study of 29 eyes in 28 cases.

Abstract: The clinical and histopathologic features of 29 eyes from 29 patients with central retinal vein occlusion (CRVO) are reported. A fresh or a recanalized thrombus was observed in each eye. This study considers the temporal aspects of the cases, and it notes the different morphologic features of the occlusion. These observations explain most of the variability of the changes observed in previous reports. We believe that these different features represent the various stages in the natural evolution of such a thrombus. The interval between CRVO and histopathologic study in our series ranged from six hours to more than 10 years. Local and systemic factors were reviewed and were found to be important in the pathogenesis of thrombus formation. Local diseases with a predisposing effect on CRVO included: glaucoma, papilledema, subdural hemorrhage, optic nerve hemorrhage, and drusen of the optic nerve head. Associated systemic diseases included: hypertension, cardiovascular and cerebrovascular disease, diabetes mellitus, and leukemia with thrombocytopenia. A fresh thrombus in the CRVO was observed in three (10.3%), and a recanalized thrombus in 26 eyes (89.7%). Endothelial-cell proliferation was a conspicuous feature in 14 (48.3%) of the eyes. Chronic inflammation in the area of the thrombus, and/or vein wall or perivenular area was observed in 14 (48.3%) of the eyes. Arterial occlusive disease was observed in seven eyes (24.6%). Cystoid macular edema was found in 26 (89.7%) of the eyes.

Retinal vascular abnormalities in the hyperlipidaemias

Abstract: Previous studies have suggested an association between hyperlipidaemia and retinal venous and arterial occlusion. To investigate this association further, the retinal arterial vasculature was studied by fluorescein angiography in forty hyperlipidaemic subjects, and clinical examination and biochemical investigations, including lipid profile, were performed in 99 patients with retinal vein occlusion and forty patients without retinal vein occlusion as a comparison group. Retinal arterial abnormalities were found on fluorescein angiography in eight patients with combined hypercholesterolaemia and hypertriglyceridaemia (type IV and V hyperlipidaemia). However no abnormalities were found in patients with familial hypercholesterolaemia (type II). Fluorescein angiography was repeated after 6 months hypolipidaemic therapy in four of the patients with retinal arterial abnormalities. Progression of retinal vascular closure was observed in two patients with poor hyperlipidaemic control and improvement in two other patients with good hyperlipidaemic control. There was a significantly higher incidence of hyperlipidaemia (P less than 0.001) and glucose intolerance (P less than 0.05) in the retinal vein occlusion group when compared to the control group, and a higher incidence of hypertension in patients with either central or branch retinal vein occlusion than in the normal population. We conclude that retinal arterial abnormalities occur in type IV and V hyperlipidaemias and that both central and branch retinal vein occlusion are associated with similar risk factors to large vessel disease.

Large capillary aneurysms secondary to retinal venous obstruction.

Abstract: Three patients had unusually large capillary aneurysms. Two of the patients had had previous branch vein occlusions, while a third had had a central retinal vein occlusion. The large capillary aneurysms were located in areas of ischaemic retina that were drained by the previously obstructed veins. Retinal ischaemia and, possibly, increased hydrostatic pressure following vein occlusion were postulated to result in the development of these atypical capillary aneurysms. They are similar in size to arterial macroaneurysms, but originate from the venous side of the capillary bed. Like typical capillary microaneurysms and arterial macroaneurysms, these large capillary aneurysms may result in visual loss from macular oedema, serous elevation of the macula, and circinate lipid exudation. Argon laser obliteration of the aneurysms appears to be effective therapy.

Bilateral Central Retinal Vein Occlusion in a Patient with Scleroderma

Abstract: A 53-year-old man with scleroderma, pulmonary fibrosis, cardiac decompensation and secondary polycythaemia, but no arterial hypertension, developed central retinal vein occlusion (CRVO) in the left eye. 1.5 years later, during the treatment with systemic steroids and anticoagulants, he developed CRVO in the right eye, and a further half year later, secondary glaucoma in the left eye and loss of the visual acuity to counting fingers at 2.5 m in the right eye and at 0.5 m in the left. Retinal vascular changes, pulmonary and cardiac insufficiency and secondary polycythemia, symptoms of scleroderma, most probably contributed to the development of bilateral CRVO.

Reappraisal of the retinal cotton-wool spot: a discussion paper.

Abstract: In 1969, Professor Norman Ashton discussed the then current views on retinal cotton-wool spots at the Section of Ophthalmology of the Royal Society of Medicine. It is appropriate now to reappraise the nature of cotton-wool spots since our thoughts on this subject have changed significantly in the intervening years. Cotton-wool spots are localized areas of dense white swelling of the retinal nerve fibre layer. They often have a zigzag internal structure, a feathered edge but an otherwise well-delineated form and an approximately 1 mm dimension; they project slightly into the vitreous and sometimes deflect retinal vessels. For many years it had been widely held that these lesions represented microinfarcts of the inner retina. There were, however, several objections to this 'microinfarction' hypothesis. Firstly, although the relationship between arteriolar occlusion and cotton-wool spots was well established for hypertensive retinopathy, local obstruction of the feeding vessel was not a universal accompaniment of cotton-wool spots, e.g. in anaemic retinopathy and carotid artery occlusion (Ashton 1970). Secondly, a fundamental difference was observed between both the clinical and the histopathological appearances of cotton-wool spots and retinal infarction. Cotton-wool spots essentially involve just the nerve fibre layer of the retina, and their dense whiteness appears to result from an accumulation of organelles in the distended axon terminals (cytoid bodies) contained within the lesions (Ashton 1970). On the other hand, retinal infarction produces a grey translucent swelling with ischaemic necrosis and vacuolation of the whole of the inner half of the retina. Ashton emphasized that the essential determinant of the cotton-wool spot organelle aggregation in axon terminals was not a feature of necrosis but was predominantly a 'living reaction' in the axon. How, then, could this aggregation of organelles in axon terminals be explained both in terms of axonal physiology and retinal circulatory pathology? The experiments ofAshton and coworkers (1966) went some way towards providing an answer. The retinal circulation of pigs was focally occluded by injection of glass microspheres into the external carotid artery with resulting embolism of small retinal arterioles. Areas of grey retinal swelling up to 6 mm in diameter appeared within a few minutes and corresponded to zones of vascular nonperfusion on fluorescein angiography. Ischaemic damage was identified histologically throughout the inner half of the retina and, even at only one hour following occlusion, nerve fibres at the borders of the lesions showed increased granularity. In the following days, the ischaemic areas became more densely white, smaller lesions becoming whiter than larger areas. Furthermore, an enormous accumulation of organelles (often showing degeneration) appeared in grossly distended axon terminals especially at the periphery of the lesions. Two possible mechanisms of intra-axonal organelle aggregation were considered: (1) proliferation of organelles in situ; (2) migration of preformed organelles by axoplasmic flow. For reasons which have been critically reviewed elsewhere (McLeod 1976), Shakib & Ashton (1966) came down in favour of the former mechanism. They suggested that a nonspecific reactive proliferation of organelles occurred in axons arising from ganglion cells which had survived at the 'hypoxic' periphery of ischaemic ('anoxic') areas. Stimulated by informal discussions with Professor Ashton, I re-evaluated retinal cottonwool spots by reviewing hundreds of fundus photographs of patients with ischaemic retinopathies. It was immediately evident that cotton-wool spots and retinal infarcts

Abnormal fibrinolysis in retinal vein occlusion

Abstract: Some cases of central and branch retinal vein occlusion are associated with and may be caused by abnormal fibrinolytic mechanisms. The abnormality we described is that of plasminogen activator enzyme deficiency, which is a treatable condition. That seven cases were seen by one practitioner in a two year period may indicate that this particular condition is under-recognised.

Retinal Vascular Occlusion

Abstract: The retinal circulation is considered to be endarterial and a closed circuit since it is supplied by only one major afferent artery, the central retinal artery, and drained by only one efferent vessel, the central retinal vein. Knowledge of retinal vascular dynamics following occlusion of the major retinal vessels and their branches has expanded dramatically since the introduction of retinal fluorescein angiography, and has paved the way for important advances in the prognosis and therapy of a variety of retinal vascular occlusions.

Functional occlusion of a cilioretinal artery.

Abstract: Functional occlusion of the cilioretinal artery in the presence of central vein occlusion is difficult to prove. We describe a case of central retinal vein occlusion in which cilioretinal artery occlusion developed after iatrogenic lowering of the blood pressure. Fluorescein angiography showed a peculiar hemodynamic sequence that demonstrated a functional origin to the cilioretinal artery occlusion.

Photocoagulation in retinal vein occlusion.

Abstract: Photocoagulation was used to treat 40 eyes, 20 with central and 20 with branch vein occlusion. Panretinal photocoagulation was used over the fundus in central vein occlusion, and regional photocoagulation over the affected area in branch vein occlusion. No complications were observed during a follow-up period of 8 to 24 months. Recent as well as long-standing cases with macular edema were treated. Visual acuity improved in 85% of eyes with central vein occlusion and 80% of eyes with branch vein occlusion. Visual acuity results were more satisfactory with early treatment.

Central retinal vein occlusion and scleroderma: implications for sclerodermatous vascular disease.

Abstract: A patient with scleroderma (progressive systemic sclerosis) who developed central retinal vein occlusion is described. The aetiology of this condition is discussed and the role of possible sclerodermatous vascular disease is highlighted. It is suggested that studies of fundal vasculature could be useful in the clinical assessment of sclerodermatous vascular disease.

Treatment of neovascularization secondary to branch retinal vein obstruction.

Abstract: Fifty patients who developed preretinal or papillary neovascularization following tributary vein occlusion were treated by laser photocoagulation. Areas of non-perfused retina within the distribution of the obstructed vein were identified by fluorescein angiography and ablated using moderately intense laser photocoagulation burns. In forty-six patients there was satisfactory atrophy of both prerentinal and papillary neovascularization without further complication or vitreous haemorrhage. Four patients who responded poorly to laser photocoagulation did so either because areas of ischaemic retina were inadequately treated or because they were unamenable to laser photocoagulation e.g., sited in the parafoveal region. Ablation of ischaemic perimacular retina together with associated intraretinal microvascular abnormalities aided the resolution of macular oedema in 19 patients. No post-operative complications could be attributed to laser photocoagulation excepting the development of fine perimacular retinal folds in one patient.

[Retinal vein periphlebitis - frequency, occurrence and diagnostic significance].

Abstract: Among 15,000 neuroophthalmological patients examined in the years 1963 to 1977, 51 showed periphlebitic changes of the retinal veins 46 of these patients were known to suffer from multiple sclerosis (MS) From his results that changes of the fundus of the eye are associated with a high degree of probability (about 90 per cent) with multiple sclerosis In the same period of time, 422 patients were found to suffer from MS From this one can calculate the relative frequency of periphlebitic changes of the retinal veins in MS cases to be about 109 per cent Apart from their diagnostic importance, the findings are also interesting because they may indicate the significance of periphlebitic changes in the etiopathogenesis of MS