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 15,891 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retinal vein occlusion (RVO) not infrequently occurs in diabetic patients. Although the aetiology is unclear, it could relate to the other microvascular complications of diabetes. In the non-diabetic, both the central (CRVO) and branch (BRVO) forms are commonly associated with hypertension and hyperlipidaemia. We have therefore studied fifty type II diabetic patients with RVO compared to a carefully matched diabetic control group (n = 50) to elucidate underlying medical conditions and hence the aetiology of RVO in diabetic patients. The two groups were well matched. Diabetics with RVO showed a strikingly high prevalence of hypertension compared to the controls (72% versus 32%: p < 0.001) and a trend to increased hyperlipidaemia (54% versus 36%). Diabetic microvascular complications were more common in the control group (diabetic retinopathy and proteinuria). No significant differences were observed in mean HbA1 or weight, but current smoking habits and blood pressure levels were increased in the diabetics with RVO. 80% of diabetic patients with the BRVO form, were hypertensive. We conclude that the main underlying medical conditions for RVO in diabetics are hypertension and hyperlipidaemia, and these may be important in the aetiology as in the non-diabetic. RVO is more common in type II rather than type I diabetes, and does not associate with the presence of diabetic microvascular complications. Clinical assessment for hypertension and hyperlipidaemia is therefore important in diabetic patients with RVO, especially if recurrence of the condition and further visual loss is to be prevented.
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PMID:Does type II diabetes predispose to retinal vein occlusion? 821 32

Retinal vein occlusion (RVO) is the most common retinal vascular disorder second to diabetic retinopathy. The main risk factors in patients with RVO are hypertension, diabetes, hyperlipidemia, increased blood viscosity and glaucoma. The pathogenesis of RVO has not yet been clarified. In these events platelets could play a very important role. In the present study the platelet response to collagen was deeply investigated. Experiments were carried out on a selected group of RVO patients, which were compared to a group of healthy subjects matched for age, sex, clinical and metabolic characteristics. In resting and activated platelets of both groups of subjects p72syk phosphorylation, phospholipase Cgamma2 phosphorylation, protein kinase C activation, intra-cellular calcium levels and nitric oxide formation were measured. Results show that platelets of patients were more responsive to collagen or ADP than healthy subjects and that the response was significantly different (p < 0.0005) at low concentrations of these agonists. In platelets of patients stimulated with collagen increased phosphorylation of p72syk and phospholipase Cgamma2 was found. Also protein kinase C was more activated in patients. In addition intracellular calcium rise induced by collagen was significantly higher in patients than in healthy subjects. RVO patients showed a lower basal level of nitric oxide both in resting and stimulated platelets compared to healthy subjects. Altogether these results suggest that the platelet hyperaggregability described in patients might be an important factor in the development of RVO contributing to the thrombogenic effects.
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PMID:Platelet activation by collagen is increased in retinal vein occlusion. 1726 50

Retinal vein occlusion (RVO) is the second most common retinal vein disease and an important cause of blindness and visual morbidity. Systemic risk factors are commonly associated with RVO, while unclear it is the role of the thrombophilic and coagulation disorders. To evaluate "classic" and "emerging" risk factors, and to establish a good treatment for RVO. Fifty patients, 31 males and 19 females, with RVO were selected for our study. RVO patients were divided into two groups: those with central retinal vein occlusion (CRVO) and those with branch retinal vein occlusion (BRVO). All patients were subjected to an anamnestic investigation and were tested for thrombophilia, coagulation disorders and hyperlipidemia. Treatment and prophylaxis were evaluated. We have named "classic" the systemic risk factors associated with RVO and "emerging" those risk factors, haemostasis related, not clearly associated with RVO. RVO occurs more commonly in patients aged over 50. "Emerging" risk factors were more frequent in CRVO, "classic" in BRVO. Hyperhomocysteinemia is the most common "emerging" risk factor related to RVO. 71.4% of tested patients had hypercholesterolemia. Treatment with LMWH would appear to be safe and effective, but the small number of patients considered not allow us a definitive evaluation of its efficacy. Although our study has shown the correlation between RVO and the "emerging" risk factors, more studies are necessary to better know the real role of thrombophilic and coagulation disorders in this disease and to determine a specific protocol for the treatment and prophylaxis of RVO.
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PMID:Retinal vein occlusion: evaluation of "classic" and "emerging" risk factors and treatment. 1966 64

Retinal vein occlusion (RVO) is the most common retinal vascular disease after diabetic retinopathy. Owing to its multifactorial nature, however, management of this condition remains a challenge. Of the two main types of RVO, branch retinal vein occlusion (BRVO) is more prevalent than central retinal vein occlusion (CRVO). Most patients develop the disease at an elderly age, and more than half of them have associated systemic disorders (e.g. hypertension, hyperlipidemia and/or diabetes mellitus). There is no evidence to suggest routine testing for heritable thrombophilias in patients with RVO. The main cause of the visual impairment is macular edema, while neovascularization of the retina and optic disc are the most serious complications leading to vitreous hemorrhage, retinal detachment and neovascular glaucoma. Macular grid laser photocoagulation is an effective treatment for macular edema in patients with BRVO and a visual acuity of 20/40 or less. Other treatment options for reducing the edema are intravitreal steroids, anti-VEGF drugs and vitrectomy. The recently introduced intravitreal application of steroids and anti-VEGF drugs may prove to be a better approach for improving visual acuity. Finally, scatter panretinal laserphotocoagulation can effectively treat neovascularization and its secondary complications.
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PMID:Retinal vein thrombosis: pathogenesis and management. 2195 4

Retinal vein occlusion (RVO) and retinal artery occlusion (RAO) cause significant visual impairment. The role of thrombophilia and cardiovascular testing is uncertain, and optimal treatment strategies have not been determined. We reviewed medical records of 39 patients with RVO and RAO (23 women and 16 men). Thrombophilia and cardiovascular evaluations were performed and outcomes were reviewed. In all, 24 (61.5%) patients had at least 1 thrombophilia. Elevated factor VIII levels were found in RVO (n = 5) but not in RAO. There are no other significant differences in thrombophilias in RVO compared to those in RAO. Most patients had hypertension(41.2% RAO and 55% RVO) and hyperlipidemia (35.5% RAO and 81.8% RVO). In all, 4 women were using oral contraceptives, 2 were pregnant or postpartum. Follow-up data was available for 28 patients (13 RAO, 15 RVO). Nineteen were treated with aspirin, four with warfarin, and one with low molecular weight heparin. Eight patients reported improvement in vision at time of follow-up (5 RAO, 3 RVO). Multiple risk factors are associated with RVO and RAO, and a complete assessment should include thrombophilia and cardiovascular studies.
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PMID:Risk Factors and Treatment Strategies in Patients With Retinal Vascular Occlusions. 2433 46

Retinal vein occlusion (RVO) is a major cause of vision loss. Of the two main types of RVO, branch retinal vein occlusion (BRVO) is 4 to 6 times more prevalent than central retinal vein occlusion (CRVO). A basic risk factor for RVO is advancing age. Further risk factors include systemic conditions like hypertension, arteriosclerosis, diabetes mellitus, hyperlipidemia, vascular cerebral stroke, blood hyperviscosity, and thrombophilia. A strong risk factor for RVO is the metabolic syndrome (hypertension, diabetes mellitus, and hyperlipidemia). Individuals with end-organ damage caused by diabetes mellitus and hypertension have greatly increased risk for RVO. Socioeconomic status seems to be a risk factor too. American blacks are more often diagnosed with RVO than non-Hispanic whites. Females are, according to some studies, at lower risk than men. The role of thrombophilic risk factors in RVO is still controversial. Congenital thrombophilic diseases like factor V Leiden mutation, hyperhomocysteinemia and anticardiolipin antibodies increase the risk of RVO. Cigarette smoking also increases the risk of RVO as do systemic inflammatory conditions like vasculitis and Behcet disease. Ophthalmic risk factors for RVO are ocular hypertension and glaucoma, higher ocular perfusion pressure, and changes in the retinal arteries.
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PMID:Risk factors for central and branch retinal vein occlusion: a meta-analysis of published clinical data. 2500 43

Retinal vein occlusion (RVO) is the second most common cause of visual loss in the Western World. RVO is usually classified into branch RVO (BRVO) and central RVO (CRVO) according to the anatomical site of the vascular occlusion. The pathogenesis of RVO is not yet fully understood, however an important event is the intraluminal thrombus formation, which is usually secondary to several conditions such as hypertension, hyperlipidemia, diabetes and thrombophilia. The blockage of venous circulation causes an elevation of intraluminal pressure in the capillaries, leading to hemorrhages and leakage of fluid within the retina, increase of interstitial pressure and a consequent reduction of retinal perfusion. Ischemia may develop resulting in secretion of vascular endothelial growth factor (VEGF) that causes further vascular leakage and retinal oedema. VEGF has therefore a leading role in RVO pathogenesis and symptoms. As a consequence use of anti-VEGF agents by intravitreal injections has become very common with the aim to improve the clinical outcomes in these patients. Currently 2 anti-VEGF agents (ranimizumab and aflibercept) have been FDA (Food and Drug Administration) and EMA (European Medicine Agency) approved for the treatment of RVO, while another VEGF inhibitor (bevacizumab) is often used "off-label" in clinical practice. Many treatment regimens have been suggested in the clinical trials with these drugs, as monthly injections or injections when needed, however the ideal regimen has not been defined yet. We conducted a systematic review searching MEDLINE for the following terms: retinal vein occlusion, ranibizumab, bevacizumab, aflibercept, vascular endothelial growth factor, macular oedema. Data were extracted by one author (AG and BE) and checked by a second (BPM, CC). Aim of this article was to review available data for each drug, focusing on their efficacy and safety trying to compare their advantages and limits.
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PMID:Anti-VEGF Therapy for Retinal Vein Occlusions. 2607 57