Nine year follow-up study of morbidity and mortality in retinal vein occlusion

Risk of stroke development following retinal vein occlusion: A systematic review and meta-analysis

Retinal vein occlusion (RVO) and cerebrovascular disease share common risk factors and may be independently associated; however, the strength and nature of this association remain unclear. We conducted a systematic review and meta-analysis, informed by studies from PubMed, Scopus, EMBASE, Web of Science, and Google Scholar until January 6, 2024, aimed to clarify this relationship. Eligible studies included cohorts observing stroke incidence in RVO patients for over a year. Pooled effect estimates were calculated using random-effects models, with subgroup analyses evaluating associations between RVO types (central and branch) and stroke subtypes (ischemic and hemorrhagic). Ten cohort studies with a total of 428,650 participants (86,299 RVO patients) were included. Compared to controls, RVO patients exhibited a significantly increased risk of stroke (pooled risk ratio [RR]=1.38, 95 % confidence interval (95 %CI)=1.34-1.41). Subgroup analyses indicated elevated risk for both ischemic (RR=1.37, 95 %CI=1.32-1.42) and hemorrhagic (RR=1.55, 95 %CI=1.08-2.22) strokes in RVO patients. Additionally, both central (RR=1.50, 95 %CI=1.27-1.78) and branch (RR=1.41, 95 %CI=1.32-1.50) RVO were associated with stroke risk. Sensitivity analyses confirmed consistent results across various criteria, and funnel plots indicated no publication bias. RVO significantly increases the risk of both ischemic and hemorrhagic stroke, regardless of RVO type, suggesting a strong independent association between these conditions.

Cutting-edge advances in nano/biomedicine: A review on transforming thrombolytic therapy

Thrombotic blockages within blood vessels give rise to critical cardiovascular disorders, including ischemic stroke, venous thromboembolism, and myocardial infarction. The current approach to the therapy of thrombolysis involves administering Plasminogen Activators (PA), but it is hindered by fast drug elimination, narrow treatment window, and the potential for bleeding complications. Leveraging nanomedicine to encapsulate and deliver PA offers a solution by improving the efficacy of therapy, safeguarding the medicine from proteinase biodegradation, and reducing unwanted effects in in vivo trials. In this review, we delve into the underlying venous as well as arterial thrombus pathophysiology and provide an overview of clinically approved PA used to address acute thrombotic conditions. We explore the existing challenges and potential directions within recent pivotal research on a variety of targeted nanocarriers, such as lipid, polymeric, inorganic, and biological carriers, designed for precise delivery of PA to specific sites. We also discuss the promising role of microbubbles and ultrasound-assisted Sono thrombolysis, which have exhibited enhanced thrombolysis in clinical studies. Furthermore, our review delves into approaches for the strategic development of nano-based carriers tailored for targeting thrombolytic action and efficient encapsulation of PA, considering the intricate interaction in biology systems as well as nanomaterials. In conclusion, the field of nanomedicine offers a valuable method for the exact and effective therapy of severe thrombus conditions, presenting a pathway toward improved patient outcomes and reduced complications.

Retinal vein occlusion is associated with stroke independent of underlying cardiovascular disease

BACKGROUND

Stroke is a leading cause of mortality and morbidity. Thus, identifying associated risk factors may lead to earlier interventions aimed at reducing the risk of stroke development. Since cardiovascular disease simultaneously increases the risk of stroke and retinal vein occlusion (RVO), we sought to determine whether RVO is associated with the risk of stroke independent of underlying cardiovascular co-morbidities.

METHODS

In this cross-sectional study, we reviewed the records of 80,754 individuals who were evaluated by an ophthalmologist over a 6-year period. We identified individuals with RVO, stroke and cardiovascular diseases including hypertension, diabetes mellitus, carotid disease, coronary artery disease and atrial fibrillation. Multivariable logistic regression models were used to analyze odds ratios for RVO and stroke.

RESULTS

After adjusting for age, sex, cardiovascular disease and other risk factors, we found that the presence of RVO was associated with an odds ratio for stroke of 1.73 (CI, 1.40-2.12, p < 0.001). The association between RVO and stroke, after adjusting for sex and cardiovascular co-morbidities, was significantly stronger in individuals younger than 50 years of age, with an odds ratio of having a stroke of 3.06 (1.34-6.25, p < 0.001), while the presence of RVO in individuals older than 85 years was not significantly associated with stroke 1.19 (0.77-1.79, p = 0.41).

CONCLUSIONS

Our findings demonstrate that RVO is significantly associated with stroke, even after adjusting for underlying cardiovascular co-morbidities. This association was highly significant in younger subjects, while not significant in older individuals.

Antithrombotic treatment for retinal vein occlusion: a systematic review and meta-analysis

BACKGROUND

Retinal vein occlusion (RVO) represents a common thrombotic disorder.

OBJECTIVES

In this meta-analysis, we evaluated the efficacy and safety of anticoagulant and antiplatelet therapy in RVO.

METHODS

MEDLINE and EMBASE were searched up to December 2021 for observational studies and randomized controlled trials including patients with RVO. Efficacy outcomes were best-corrected visual acuity improvement, recurrent RVO, fluorescein angiography improvement, cardiovascular events, and safety outcomes were major bleeding and intraocular bleeding.

RESULTS

A total of 1422 patients (15 studies) were included. Antiplatelet therapy was administered to 477 patients (13 studies), anticoagulant therapy to 312 patients (12 studies), and 609 (7 studies) patients received no antithrombotic treatment. The treatment duration ranged between 0.5 and 3 months. The median follow-up duration was 12 months. Best-corrected visual acuity improvement was reported in 58% of the patients (95% confidence interval [CI], 45%-69%) overall, 64% (95% CI, 58%-71%) in those on anticoagulant therapy, and 33% (95% CI, 21%-47%) in those on antiplatelet therapy. The rates of recurrent RVO was 11% (95% CI, 7%-17%), 7% (95% CI, 2%-19%), and 15% (95% CI, 8%-28%), respectively. The rate of recurrent RVO in untreated patients was 9% (95% CI, 6%-14%). The rate of major bleeding was 5% (95% CI, 3%-9%) overall, 4% (95% CI, 2%-9%) in those on anticoagulant therapy, and 7% (95% CI, 2%-23%) in those on antiplatelet therapy.

CONCLUSION

Anticoagulant therapy was associated with higher visual acuity improvement and fewer recurrent RVO events than antiplatelet therapy, at the cost of an acceptable proportion of bleeding complications.

Association between proteinuria and retinal vein occlusion in individuals with preserved renal function: a retrospective cohort study

PURPOSE

To investigate the association between proteinuria and the incidence of retinal vein occlusion (RVO) in individuals with preserved renal function.

METHODS

We conducted a retrospective cohort study from 2005 to 2020 using the JMDC Claims Database, a large database of health check-ups and administrative claims in Japan. Individuals who underwent annual health check-ups were included. Participants were classified into three groups based on the protein concentration in their urine: negative (≤10 mg/dl), trace (10-30 mg/dl) and positive (≥30 mg/dl). We estimated hazard ratios (HRs) for the development of RVO using Cox regression analyses with adjustment for baseline characteristics by the matching weights calculated from the multiple propensity scores. The cumulative incidence of RVO between the weighted groups was calculated using the Kaplan-Meier estimator.

RESULTS

There were 1 635 212 eligible participants, among whom 2360 developed RVO. The mean follow-up period was 1036 ± 951 days. The adjusted HRs for RVO were 1.10 (95% confidence interval 0.92-1.33) and 1.46 (1.19-1.78) in the groups with trace and positive proteinuria compared with negative proteinuria respectively. The cumulative incidence rates of RVO at 7 years were 0.40%, 0.43% and 0.55% in the groups with negative, trace and positive proteinuria, respectively.

CONCLUSION

Positive proteinuria was independently associated with an increased incidence of RVO in individuals with preserved renal function. Proteinuria may be a novel risk factor for RVO development.

Evaluation of augmentation index and pulse wave velocity measurements in central retinal vein occlusion patients with and without hypertension

PURPOSE

To evaluate arterial stiffness using the pulse wave velocity (PWV) and augmentation index (AI) in central retinal vein occlusion (CRVO) patients.

METHODS

Forty-two CRVO patients (i.e., CRVO group) and 54 healthy controls (i.e., control group) were included in this comparative and cross-sectional study. The PWV, AI and augmentation pressure were measured with a noninvasive, oscillometric method.

RESULTS

The mean PWV, AI and augmentation pressure values were significantly higher in CRVO patients than in controls (p = 0.024, p < 0.001 and p = 0.001, respectively). The mean augmentation pressure, AI and PWV measurements were not statistically significant between CRVO patients with and without hypertension (p = 0.856 and p < 0.526, p = 0.432, respectively). Age, presence of hypertension, AI and PWV were found to be as independent risk factors of CRVO development (OR = 2.21, 95% CI [1.44, 3.38] and OR = 2.40, 95% CI [1.50, 3.86], OR = 3.2, 95% CI [1.70, 5.60] and OR = 5.70, 95% CI [2.00, 18.50], respectively).

CONCLUSION

The AI and PWV values were significantly higher in CRVO patients than in controls. These results indicate that similar abnormalities in the arterial wall structure may play an important role in the pathogenesis of the CRVO and cardiovascular diseases. In addition, our findings show that each patient with RVO should be examined in terms of systemic vascular pathologies.

Retinal vein occlusion: drug targets and therapeutic implications

INTRODUCTION

The pathogenesis of retinal vein occlusion (RVO) is extremely complex and includes several mediators. These mediators represent potential drug targets that can be used in the development of intravitreal drugs.

AREAS COVERED

PubMed/MEDLINE databases were accessed between April-May 2021 to find the most relevant scientific papers regarding drug targets and therapeutic implications in RVO, focusing on current therapeutic options and potential cornerstones of future advances in treatment.

EXPERT OPINION

Before the introduction of intravitreal therapies, the visual outcome following a diagnosis of RVO was extremely poor. Anti-VEGF and corticosteroid treatments have radically changed RVO prognosis, helping to preserve patients' visual function and their quality of life. According to current clinical data, anti-VEGF and corticosteroid drugs are associated with both pros and cons; the present recommendation is to employ anti-VEGF molecules as a first-line treatment. Advances in our understanding of the biomolecular characteristics of RVO offer a solid basis for the development of new therapeutic targets and treatments.

Systemic antiplatelet agents and anticoagulants in eyes with branch retinal vein occlusion

Purpose

The purpose of this study was to investigate the effect of systemic antiplatelet agents and anticoagulants on the structural and functional outcomes of eyes with branch retinal vein occlusion (BRVO).

Methods

A retrospective longitudinal cohort study was performed on BRVO patients evaluated at a single tertiary care referral center between 2009 and 2017. Medical records were reviewed for antiplatelet agent and anticoagulant use including aspirin, clopidogrel, warfarin, rivaroxaban, apixaban, or dabigatran prior to BRVO onset. In addition, optical coherence tomography (OCT) parameters, clinical outcomes, and treatment patterns were also recorded.

Results

A total of 354 BRVO eyes were identified with a mean follow-up time of 36 months. Antiplatelet or anticoagulant use was associated with presence of cystoid macular edema (CME) at presentation after controlling for potential confounding variables in a multivariate logistic regression. Multivariate regression also revealed an association between foveal hemorrhage at presentation and use of antiplatelet or anticoagulant medications. There were no significant differences in visual acuity or prevalence of CME at the final visit in those with antiplatelet/anticoagulant use compared to those not on these agents.

Conclusion

Although the use of systemic antiplatelet or anticoagulant agents was associated with increased prevalence of CME and foveal hemorrhage at presentation of BRVO, the use of these medications was not associated with different visual or structural outcomes at the final visit.

Platelet and Thrombophilia-Related Risk Factors of Retinal Vein Occlusion

Retinal vein occlusion (RVO) is a heterogenous disorder in which the formation of a thrombus results in the retinal venous system narrowing and obstructing venous return from the retinal circulation. The pathogenesis of RVO remains uncertain, but it is believed to be multifactorial and to depend on both local and systemic factors, which can be divided into vascular, platelet, and hypercoagulable factors. The vascular factors include dyslipidaemia, high blood pressure, and diabetes mellitus. Regarding the platelet factors, platelet function, mean platelet volume (MPV), platelet distribution width (PDW), and platelet large cell ratio (PLCR) play key roles in the diagnosis of retinal vein occlusion and should be monitored. Nevertheless, the role of a hypercoagulable state in retinal vein occlusion remains unclear and requires further studies. Therefore, the following article will present the risk factors of RVO associated with coagulation disorders, as well as the acquired and genetic risk factors of thrombophilia. According to Virchow’s triad, all factors mentioned above lead to thrombus formation, which causes pathophysiological changes inside venous vessels in the fundus of the eye, which in turn results in the vessel occlusion. Therefore, a diagnosis of retinal vein occlusion should be based on both eye examination and general examination, including laboratory tests.

ASSOCIATION OF RETINAL VEIN OCCLUSION WITH CARDIOVASCULAR EVENTS AND MORTALITY: A Systematic Review and Meta-analysis

PURPOSE

Previous studies examining the association of retinal vein occlusion (RVO) and cardiovascular events have been inconsistent and have mostly focused on stroke and myocardial infarction. The goal of this study is to use meta-analysis to examine the available evidence examining the association of RVO with incident cardiovascular events and mortality.

METHODS

Systematic review and meta-analysis of all longitudinal cohort studies published in PubMed, Embase, and the Cochrane Library from inception to April 7, 2018, that evaluated the association of baseline RVO and incident cardiovascular events and/or mortality, that provided multivariate-adjusted risk estimates with 95% confidence intervals (95% CIs), and that had average follow-up ≥1 year. The Newcastle-Ottawa scale was used to assess study quality. Multivariate-adjusted risk estimates with 95% CI along with study characteristics were extracted from each study, and pooled risk ratios (RRs) with 95% CI were generated using a random-effects model with inverse-variance weighting to account for heterogeneity. Main outcomes were incident stroke (fatal or nonfatal), myocardial infarction, heart failure, peripheral arterial disease, all-cause mortality, and cardiovascular mortality.

RESULTS

Fifteen cohort studies with a total of 474,466 patients (60,069 with RVO and 414,397 without RVO) were included. Each study had Newcastle-Ottawa scale score ≥6, indicating moderate-to-high quality. Retinal vein occlusion was associated with increased risk of stroke (RR = 1.45; 95% CI, 1.31-1.60), myocardial infarction (RR = 1.26; 95% CI, 1.17-1.37), heart failure (RR = 1.53; 95% CI, 1.22-1.92), peripheral arterial disease (RR = 1.26; 95% CI, 1.09-1.46), and all-cause mortality (RR = 1.36; 95% CI, 1.02-1.81), but was not associated with increased risk of cardiovascular mortality (RR = 1.78; 95% CI, 0.70-4.48).

CONCLUSION

This review suggests patients with RVO have an increased risk of cardiovascular events and all-cause mortality. More studies are needed to determine the highest risk periods for cardiovascular events and mortality after RVO and whether immediate cardiovascular evaluation and intervention will improve outcomes.

Clinical characteristics of branch retinal vein occlusion with increased retinal haemorrhage during treatment for macular oedema

This study was performed to evaluate clinical characteristics of branch retinal vein occlusion (BRVO) patients with increased retinal haemorrhage during macular oedema (MO) treatment. Patients were divided into increased and non-increased retinal haemorrhage groups. The former group was sub-divided based on the degree of increase: < 50% or ≥ 50%. Baseline characteristics, clinical data, and best vision achieved before and after increased retinal haemorrhage were assessed. Sixty-eight eyes of 68 patients were included. Forty-six eyes were non-increased, 11 eyes experienced < 50% increase in retinal haemorrhage, and 11 eyes had ≥ 50% increase. Ischaemic BRVO was related to increased haemorrhage based on the multivariate analysis. The ≥ 50% increase group exhibited higher baseline central subfield macular thickness (CSMT), poorer baseline best corrected visual acuity (BCVA), and longer mean periods between the final intravitreal injections and the time increased retinal haemorrhages were observed, compared to the < 50% group. The best vision achieved before and after increased haemorrhage was significantly worse in the ≥ 50% group. In conclusion, the ischaemic type of BRVO is related to increased retinal haemorrhage during MO treatment, and a ≥ 50% increase in haemorrhages is associated with higher CSMT and poorer BCVA at baseline, with poor visual gain.

Endothelial dysfunction and impaired arterial wall properties in patients with retinal vein occlusion

Retinal vein occlusion (RVO) is a common retinal vascular lesion, and a leading cause of visual impairment. Patients with RVO have an increased risk for cardiovascular disease and share multiple common risk factors. In this study, we investigated the endothelial function and arterial stiffness of patients with RVO compared to healthy-control (CL) subjects. We enrolled 40 consecutive patients with RVO and 40 CL subjects. RVO was diagnosed by an ophthalmologist, endothelial function was evaluated by flow mediated dilation (FMD) in the brachial artery, and carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx) of the radial artery were measured to evaluate arterial stiffness and reflected waves, respectively. No significant differences were detected between the studied groups in sex, age, presence of hypertension or dyslipidemia, body mass index, systolic and diastolic blood pressure levels, total cholesterol levels, and smoking habits (p > 0.05 for all). However, patients with RVO had impaired FMD (p = 0.002) and increased PWV (p = 0.004), even after adjustment for several confounders. Both FMD and PWV were also significantly and independently associated with the development of RVO. Furthermore, a significant and positive correlation between PWV and systolic blood pressure existed only in the CL group. Therefore, we have shown that RVO is associated with significant endothelial dysfunction and increased arterial stiffness. Our results strengthen the vascular theory, according to which, systemic endothelial dysfunction and arteriosclerosis play a significant role in the pathogenesis of RVO.

Guidelines for the Management of Retinal Vein Occlusion by the European Society of Retina Specialists (EURETINA)

The high prevalence of cardiovascular disease particularly in the elderly population is associated with retinal vascular disease. Retinal vein occlusions represent severe disturbances of the hypoxia-sensitive neurosensory retina. Acute and excessive leakage leads to the diagnostic hallmarks of retinal hemorrhage and edema with substantial retinal thickening. Advanced diagnostic tools such as OCT angiography allow to evaluate retinal ischemia and identify the risk for late complications and will soon reach clinical routine besides fluorescein angiography. Accordingly, the duration of non-perfusion is a crucial prognostic factor requiring timely therapeutic intervention. With immediate inhibition of vascular leakage, anti-VEGF substances excel as treatment of choice. Multiple clinical trials with optimal potential for functional benefit or a lesser regenerative spectrum have evaluated aflibercept, ranibizumab, and bevacizumab. As retinal vein occlusion is a chronic disease, long-term monitoring should be individualized to combine maintenance with practicability. While steroids may be considered in patients with systemic cardiovascular risk, surgery remains advisable only for very few patients. Destructive laser treatment is an option if reliable monitoring is not feasible. Ophthalmologists are also advised to perform a basic systemic workup to recognize systemic concomitants. The current edition of the EURETINA guidelines highlights the state-of-the-art recommendations based on the literature and expert opinions in retinal vein occlusion.

A Case of Left Ventricular Thrombus with Superior Mesenteric Vein Thrombosis Due to Atopic Dermatitis

A 55-year-old man was presented to the emergency room because of abdominal pain for 4 days. He had a history of atopic dermatitis. Left ventricular (LV) asynergy and thrombus was detected on echocardiography, and superior mesenteric vein thrombosis was detected by computed tomography. There are no reported cases of this combination of thrombi. We hypothesized that the reason for this complication is the combination of coagulation disorder due to atopic dermatitis, silent myocardial infarction, and exacerbation of the coagulation abnormality due to bacteremia, leading to superior mesenteric vein and LV thrombosis. Atopic dermatitis that has potential risk factors of thrombus with sepsis could provoke thrombophilic state. Atopic dermatitis is a common disease, but continuous medical care is essential.

Atrial fibrillation in retinal vascular occlusion disease and non-arteritic anterior ischemic optic neuropathy

Background

Patients with retinal vascular occlusion disease have an increased risk for ischemic stroke and share some risk factors with cerebrovascular disease. The purpose of this study was to analyze the prevalence of atrial fibrillation (AF) in subjects with retinal vascular occlusive disease and anterior ischemic optic neuropathy and to compare these data to an ischemic stroke group.

Methods

Prospective, observational single-center trial. Subjects with retinal artery occlusion (RAO), retinal vein occlusion (RVO) and anterior ischemic optic neuropathy (AION) were included. Patients with ischemic stroke (IS) from a previous observational trial were used as control. Investigation included 7-day Holter ECG, echocardiography, duplex ultrasonography of the carotid arteries, and 24-hour blood pressure monitoring. Further vascular risk factors were documented.

Results

During the 1-year study period, 101 patients were recruited. The control group with ischemic stroke consisted of 272 subjects. At inclusion, the prevalence of AF was 12% (RAO), 10.2% (RVO), 11.1% (NAION) and 15.8% (IS). The final prevalence after Holter ECG rose to 16% (RAO), 18.4% (RVO), 14.8% (NAION) and 26.5% (IS). No significant difference was measured between groups.

Conclusions

We detected a similar prevalence of AF in all groups. RVO patients tended to exhibit a higher AF detection rate and lower number needed to screen than RAO and NAION. The detection of AF rose considerably via Holter ECG. As a consequence, we recommend prolonged ECG monitoring in patients with acute ophthalmic vascular diseases.

AMBULATORY BLOOD PRESSURE PATTERNS IN PATIENTS WITH RETINAL VEIN OCCLUSION

PURPOSE

Failure of blood pressure (BP) to dip during sleep (nondipper pattern) is associated with cardiovascular disease and stroke. The prevalence and degree of nondipping and masked hypertension in patients with retinal vein occlusion (RVO), which is associated with stroke, has not been previously examined.

METHODS

We measured clinic and 24-hour ambulatory BPs in 22 patients with RVO and 20 control participants without known eye disease matched by age and sex. Mean BP dipping, defined as the ratio of difference in mean awake and sleep systolic BPs to mean awake systolic BP, and masked and nocturnal hypertension were compared between groups.

RESULTS

Mean 24-hour ambulatory BP was 144/79 mmHg among those with RVO and 136/77 mmHg among controls. Patients with RVO had an almost 2-fold higher prevalence of nondipping pattern (80.8% [95% confidence interval, 52.8-94.1] vs. 50.4% [95% confidence interval, 26.1-74.5]; P = 0.008). Average sleep systolic BP dip in patients with RVO was 6.1% versus 11.9% in controls (P = 0.004). More patients with RVO had masked hypertension by ambulatory BPs than controls (71% vs. 50%), but this difference was not statistically significant.

CONCLUSION

Our data suggest an association between RVO and nondipper BP pattern. Ambulatory BP monitoring may be useful in the evaluation of patients with RVO by identifying those who may benefit from more aggressive BP control.

Association between retinal vein occlusion and an increased risk of acute myocardial infarction: A nationwide population-based follow-up study

OBJECTIVE

To investigate a possible association between retinal vein occlusion (RVO) and an increased risk of developing acute myocardial infarction (AMI).

DESIGN

A population-based retrospective cohort study using the entire population of the Taiwan National Health Insurance Research Database (NHIRD) from 1st January, 2001 to 31st December, 2013.

METHODS

A total of 37921 subjects with RVO were enrolled in the RVO group, and 113763 subjects without RVO were enrolled in the comparison group. The comparison group consisted of randomly selected individuals who were propensity score (PS)-matched with the RVO group at a ratio of 1:3, based on age, gender, obesity, stroke, hyperviscosity syndrome, glaucoma, and the use of antithrombotic drugs. A log-rank test was used to compare the cumulative hazard of AMI between the two groups. A multivariate Cox regression analysis was used to estimate the adjusted hazard ratios (HRs) of AMI, adjusted for PS, diabetes, hypertension, hyperlipidemia, congestive heart failure, and chronic renal failure.

RESULTS

The mean age of the cohort was 62.4±13.2 years. RVO patients had significantly higher proportions of diabetes, hypertension, hyperlipidemia, congestive heart failure, and chronic renal failure than the comparisons. The mean follow-up period was 5.52 years in the RVO group and 5.55 years in the comparison group (p = 0.16). A log-rank test comparing the cumulative hazard curves of AMI for the two groups revealed a significant difference (p<0.0001). In the multivariate Cox regression after adjustment for PS and confounders, the RVO group had a significantly higher risk of AMI (adjusted HR = 1.21; 95% CI: 1.13 to 1.30). When the RVO group was divided into central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) and analyzed separately, both groups had significantly higher adjusted HRs for developing AMI than the comparison group. Moreover, the CRVO group had a significantly higher risk of AMI than the BRVO group.

CONCLUSIONS

People with RVO are at significantly greater risk of developing AMI than individuals without RVO.

Impact of Retinal Vein Occlusion on Stroke Incidence: A Meta-Analysis

Background

Considerable controversy exists on the association between retinal vein occlusion (RVO) and stroke risk. Therefore, we conducted a meta‐analysis to assess the relationship between RVO and stroke risk.

Methods and Results

PubMed, EMBASE, and the Cochrane library databases were searched for cohort studies with data on RVO and stroke risk. Studies that reported adjusted relative risks (RRs) with 95% CIs of stroke associated with RVO were included. Stratified analyses were conducted according to key characteristics. A total of 5 articles including results from 6 prospective cohort studies with 431 cases of stroke and 37 471 participants were included in the meta‐analysis. Overall, after adjustment for established cardiovascular risk factors, participants with RVO at baseline were considerably more associated with a greater incidence of stroke risk (combined RR: 1.50, 95% CI: 1.19–1.90), compared to participants without RVO. The results were more pronounced for stroke (RR: 1.72, 95% CI: 1.24–2.37) in the stratified with a stroke history. The risk of stroke was nonsignificant in male subjects (RR: 1.20, 95% CI: 0.96–1.49) and in female subjects (RR: 0.93, 95% CI: 0.64–1.34). The presence of both central RVO (RR: 1.90, 95% CI: 1.46–2.48) and branch RVO (RR: 1.79, 95% CI: 1.18–2.72) was associated with increased risk of stroke. Stratifying by age, the associations between RVO and risk of stroke were similar between the age range in the cohorts that ranged from 50 to 59 years and 60 to 69 years.

Conclusions

Exposure to RVO was associated with an increased risk of stroke, especially in subjects aged between 50 and 69 years. Future studies on the effect of RVO treatment and modifiable risk factor reduction on stroke risk in RVO patients are warranted.

Evaluation of the Association Between Retinal Vein Occlusion and the Risk of Atrial Fibrillation Development: A 12-Year, Retrospective Nationwide Cohort Study

We aimed to evaluate the risk of atrial fibrillation (AF) development following retinal vein occlusion (RVO). We performed a nationwide propensity score-matched cohort study by retrospectively reviewing a database from the Korean National Health Insurance Service, comprising approximately 1 million random subjects. RVO and AF were diagnosed based on the Korean Classification of Disease codes. The RVO group was composed of patients with an initial diagnosis of RVO made between 2003 and 2007 (n = 1,801), excluding those who were diagnosed in 2002. The comparison group was composed of randomly selected patients (5 for each patient with RVO, n = 8,930) who were matched to the RVO group according to sociodemographic factors and the year of enrollment. Each sampled patient was tracked until 2013. The predictive value of RVO for AF was analyzed using Cox regression analysis with a hazard ratio (HR) and confidence interval (CI). AF developed in 6.5% of patients in the RVO group and 4.0% of those in the comparison group (p < 0.001). RVO was associated with a greater risk of AF development after adjusting for possible confounders (HR, 1.35; 95% CI, 1.09–1.67). An association between RVO and subsequent AF development was found after adjusting for possible confounding factors.

Sudden Vision Loss and Mortality: The Jackson Heart Study

PURPOSE

It is unknown whether sudden vision loss (SVL) is an independent marker for future cardiovascular disease (CVD) events in African Americans. We examined the hazard of future stroke or myocardial infarction (MI) and mortality associated with self-reported SVL lasting 24 hours or longer in a cohort of African Americans enrolled in the Jackson Heart Study (JHS).

METHODS

The study sample comprised 4670 African Americans aged 20-95 years enrolled in the JHS without previous coronary heart disease or stroke at baseline. All participants who responded to the question "Have you ever had any sudden loss of vision or blurring, lasting 24 hours or longer?" on the baseline stroke questionnaire were included in the study. Ten years of follow-up data was used. Cox proportional hazards modeling was used to examine the association between SVL (n = 142) and risk of future stroke/MI and mortality.

RESULTS

In age- and sex-adjusted Cox models, SVL was significantly associated with higher hazards of future stroke/MI (hazard ratio, HR, 2.08, 95% confidence interval, CI, 1.09-3.96) and mortality (HR 1.73, 95% CI 1.07-2.78). After adjusting for diabetes mellitus, total/high-density lipoprotein cholesterol ratio, smoking, hypertension and income, the relationships between SVL and future stroke/MI (adjusted HR 1.51, 95% CI 0.78-2.90) or mortality (adjusted HR 1.29, 95% CI 0.78-2.11) were no longer significant.

CONCLUSIONS

Self-reported SVL lasting 24 hours or longer was significantly associated with future stroke/MI and mortality, but its effect is likely a surrogate for underlying CVD risk factors rather than being an independent predictor.

Associations of retinal artery occlusion and retinal vein occlusion to mortality, stroke, and myocardial infarction: a systematic review

Retinal vascular events are perceived to be related to various cardiovascular complications. We conducted a systematic review to assess the relationship between retinal artery/vein occlusions (RAO/RVO) and the incidence of mortality, stroke, and myocardial infarction (MI). A comprehensive electronic literature search selected 93 relevant studies between 1992-2015: 16 articles qualified for inclusion (7 for mortality rate and MI, 11 for stroke). No published articles examined associations of RAO to mortality or MI, but only to stroke. Because of the heterogeneity of studies, no meta-analysis was performed. The association with mortality risk was highest at ~34.7% in RVO subgroup; whereas for MI, the risk was comparatively lower at 3.9-5.7% for RVO. There was no significant difference in stroke rate when comparing central and branch RVO subgroups (6.5%), but was significantly higher at 19.6-25% in RAO. There is a positive association of retinal vascular events to mortality, stroke, and MI. RAO is associated with a higher risk of stroke. Given that RAO and RVO patients would generally present to ophthalmologists, their high cardiovascular risk should include a referral for cardiovascular assessment as part of their management protocol.

Relationship between retinal vascular occlusions and incident cerebrovascular diseases: A systematic review and meta-analysis

Several studies investigating the role of retinal vascular occlusions, on cerebrovascular diseases (CVD) have been reported, but the results are still inconsistent. We therefore sought to evaluate the relationship between retinal vascular occlusions and CVD.We systematically searched the Cochrane Library, PubMed, and ScienceDirect databases through January 31, 2016 for studies evaluating the effect of retinal vascular occlusions on the risk of CVD. Data were abstracted using predefined criteria, and then pooled by RevMan 5.3 software.A total of 9 retrospective studies were included in this meta-analysis. When compared with individuals without retinal vascular occlusions, both individuals with retinal artery occlusion (RAO) (odds ratio [OR] = 2.01, 95% confidence interval [CI]: 1.21-3.34; P = 0.005) and individuals with retinal vein occlusion (RVO) (OR = 1.37, 95% CI: 1.24-1.50; P < 0.00001) had higher risks of developing CVD. Additionally, both individuals with central retinal artery occlusion (CRAO) (OR = 2.00, 95% CI: 1.12-3.56; P = 0.02) and branch retinal artery occlusion (BRAO) (OR = 1.60, 95% CI: 1.03-1.48; P = 0.04) were significantly associated with increased risk of CVD.Published literatures support both RVO and RAO are associated with increased risks of CVD. Further prospective studies are needed to confirm these findings.

Retinal vein occlusion and the risk of acute myocardial infarction development: a 12-year nationwide cohort study

The goal of this study was to evaluate the risk of developing acute myocardial infarction (AMI) following retinal vein occlusion (RVO). A retrospective cohort study was performed from the National Health Insurance Service and comprised 1,025,340 random subjects who were followed from 2002 to 2013. Patients with RVO in 2002 were excluded. The RVO group was composed of patients who received an initial RVO diagnosis between January 2003 and December 2007 (n = 1677). The comparison group was selected (five patients per RVO patient; n = 8367) using propensity score matching according to sociodemographic factors and the year of enrolment. Each patient was tracked until 2013. The Cox proportional hazard regression model was used. AMI developed in 7.6% of the RVO group and 5.3% of the comparison group (p < 0.001) for 7.7 median follow-up periods. RVO increased the risk of AMI development [hazard ratio (HR) = 1.25; 95% Confidence Interval (CI) 1.02 to 1.52]. In the subgroup analysis, RVO patients aged <65 years and the males within this age group had an adjusted HR of 1.47 (95% CI 1.10 to 1.98) and an adjusted HR of 2.00 (95% CI 1.38 to 2.91) for AMI development, respectively. RVO was significantly associated with AMI development.

Venous and Arterial Thrombosis: Is There a Link?

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.

Myocardial performance is impaired in patients with branch retinal vein occlusion

OBJECTIVE

To investigate whether the Tei index, which is an indicator of global myocardial function and an independent predictor of cardiac death, is increased in patients with branch retinal vein occlusion (BRVO).

METHODS

The Tei index was used to evaluate myocardial performance, in addition to conventional echocardiographic evaluation of myocardial structural and functional changes, in patients with BRVO, patients with hypertension and healthy controls.

RESULTS

Out of 36 patients with BRVO (18 female, 18 male; 17 hypertensive, 19 normotensive), 29 patients with hypertension (15 female, 14 male) and 28 healthy controls (15 female, 13 male), there were no significant between-group differences in age and sex. The mitral A wave was higher and mitral E/A ratio, mitral E wave and ejection time were lower, in patients with BRVO than in healthy controls. Mean Tei index was significantly higher in the BRVO group than in patients with hypertension or healthy controls. Compared with healthy controls, the Tei index was significantly higher in hypertensive and normotensive patients with BRVO.

CONCLUSION

Myocardial performance is decreased in patients with BRVO, independent of whether or not they have hypertension.

Bidirectional association between the risk of comorbidities and the diagnosis of retinal vein occlusion in an elderly population: a nationwide population-based study

BACKGROUND

Retinal vein occlusion (RVO) is the second most common retinal vascular disease, with peak incidence at 70years of age. However, the bidirectional association between the risk of comorbidities and the diagnosis of RVO in this population is uncertain.

METHODS

A population-based cohort of 1,784,960 patients 70years of age and older retrieved from the Taiwan National Health Insurance Research Database between 2000 and 2010. Risks of comorbidities were assessed 5years before and after the diagnosis of RVO.

RESULTS

In our study, 3393 subjects had central RVO (CRVO) and 6688 subjects had branch RVO (BRVO). Before the diagnosis of RVO, patients showed increased risks for the following comorbidities: hypertension (odds ratio [OR]=1.83, 95% confidence interval [CI], 1.74-1.93), dyslipidemia (OR=1.29, [1.23-1.35]), DM (OR=1.29, [1.23-1.35]), liver disease (OR=1.22, [1.16-1.29]), renal disease (OR=1.30, [1.23-1.37]), and cerebrovascular disease (OR=1.16, [1.11-1.21]). After the diagnosis of RVO, patients were at greater risk of developing DM (adjusted hazard ratio [AHR]=1.12, [1.06-1.19]), PAD (AHR=1.17, [1.08-1.27]), and MACE (AHR=1.35, [1.25-1.46]); however, the risk of all-cause mortality was unchanged. Elderly patients with CRVO had a significantly higher risk of all-cause mortality (AHR=1.09, [1.02-1.17]), whereas patients with BRVO showed no significant differences in mortality.

CONCLUSION

This study suggests bidirectional association between the risk of comorbidities and the diagnosis of RVO in an elderly population.

Mortality in patients with central retinal vein occlusion

PURPOSE

To assess mortality in patients with central retinal vein occlusion (CRVO).

DESIGN

Registry-based cohort study.

PARTICIPANTS AND CONTROLS

Four hundred thirty-nine photographically verified CRVO patients and a control cohort of 2195 unexposed subjects matched by age and gender and alive on the date CRVO was diagnosed in the corresponding case.

METHODS

Data from nationwide registries were used to compare mortality rates in CRVO patients with a control cohort over a mean follow-up of 5.1 years for cases and of 5.7 years for controls.

MAIN OUTCOME MEASURES

Hazard ratios (HRs) obtained by Cox regression and standardized mortality ratios (SMRs) stratified by age and gender served as measures of relative mortality risk.

RESULTS

Mortality was higher in patients with CRVO (HR, 1.45; 95% confidence interval [CI], 1.19-1.76) than in the control cohort, adjusted for age, gender, and time of diagnosis. Mortality was comparable between the 2 groups (HR, 1.19; 95% CI, 0.96-1.46) when adjusting for overall occurrence of cardiovascular disease and diabetes. Subgroup analysis found that the age-stratified mortality rate was increased significantly in the total group of men (SMR, 1.27; 95% CI, 1.03-1.56) and in women 60 to 69 years of age (SMR, 1.94; 95% CI, 1.22-3.08).

CONCLUSIONS

Central retinal vein occlusion was associated with an overall increase in mortality compared with controls that was attributed statistically to cardiovascular disorders and diabetes. We recommend treatment of hypertension and diabetes, if present, and referral of patients found to have CRVO who are not already being treated by a primary care physician.

Risk factors, antithrombotic treatment and outcome in retinal vein occlusion: an age-related prospective cohort study

OBJECTIVES

Antithrombotic treatment for retinal vein occlusion (RVO) is controversial, although RVO has been surmised as a predictor of a subsequent vascular event. We aimed to evaluate risk factors, the effects of antithrombotic therapy and the occurrence of subsequent vascular events in patients with a first episode of RVO, according to age of RVO onset.

METHODS

In this prospective cohort study, patients with central (CRVO) and branch RVO (BRVO) confirmed by fluorescein angiography were studied; they were divided according to age. Cardiovascular risk factors and thrombophilia were evaluated. Anticoagulants or aspirin were given for at least 3 months. Patients were followed every 6-12 months and vascular events were recorded.

RESULTS

One hundred CRVO and 32 BRVO patients were enrolled. Five of 60 (8.3%) patients <50 yr and 4/72 (5.5%) over 50 yr had a hereditary thrombophilic defect. One or more cardiovascular risk factors were found in 35 (58%) patients of the younger group, and in 66 (91%) of the older group (P < 0.001). Antithrombotic treatment led to both a satisfactory recanalization of occluded veins and visual acuity improvement especially in younger patients. Vascular events occurred in 19 (14%) cases after 4 ± 3.3 yr from RVO, more frequently in older than in younger patients (22% vs. 5%, P = 0.005).

CONCLUSIONS

Distribution of cardiovascular, but not of thrombophilic risk factors seems to be influenced by age in RVO patients. Patients with a first RVO, especially those >50 yr, are likely at risk of a subsequent vascular event.

Comorbidity in patients with branch retinal vein occlusion: case-control study

OBJECTIVES

To evaluate comorbidity before and after the diagnosis of branch retinal vein occlusion to determine whether it is a consequence of arterial thickening and therefore could serve as a diagnostic marker for other comorbidities and to evaluate the risk factors for the development of such occlusion.

DESIGN

Case-control study with prospective follow-up data from Danish national registries.

SETTING

Four secondary referral centres covering about 80% of the Danish population (4.4 million).

PARTICIPANTS

1168 patients with photographically verified branch retinal vein occlusion and 116,800 controls alive and aged ≥ 40 when the occlusion was diagnosed in the corresponding case.

MAIN OUTCOME MEASURES

The risk of comorbidity 10 years and 1 year before the diagnosis of branch retinal vein occlusion and the incident comorbidity in a mean period of seven years after the diagnosis, with odds ratios and incidence rate ratios adjusted for age, sex, and year of diagnosis.

RESULTS

Risk factors present 10 years and 1 year before the diagnosis of branch retinal vein occlusion included peripheral artery disease (odds ratio 1.83, 95% confidence interval 1.14 to 2.95), diabetes (1.74, 1.40 to 2.17) and arterial hypertension (2.16, 1.86 to 2.51). After the diagnosis, patients had an increased risk of developing arterial hypertension (incidence rate ratio 1.37, 95% confidence interval 1.15 to 1.57), diabetes (1.51, 1.17 to 2.04), congestive heart failure (1.41, 1.12 to 1.68), and cerebrovascular disease (1.49, 1.27 to 1.76).

CONCLUSION

Diabetes, hypertension, and peripheral artery disease are associated with an increased risk of developing branch retinal vein occlusion up to a decade later. Branch retinal vein occlusion was associated with an increased risk of subsequently developing hypertension, diabetes, congestive heart failure, and cerebrovascular disease, emphasising the importance of preventive initiatives. These results fit the assumption that branch retinal vein occlusion is a consequence of arterial thickening and that the arteriovenous crossing signs that precede it are hallmarks of arterial disease.

Impaired systemic vascular endothelial function in patients with branch retinal vein occlusion

PURPOSE

To evaluate systemic endothelial function in patients with branch retinal vein occlusion (BRVO).

METHODS

Twenty-seven patients with BRVO (BRVO group, 8 men, 19 women; mean age, 65.4 ± 1.3), 10 patients with systemic hypertension and no other systemic or ocular disease (hypertension group, 6 men, 4 women; mean age, 70.4 ± 2.2), and 10 healthy volunteers (healthy group, 3 men, 7 women; mean age, 63.8 ± 2.1) were enrolled. We excluded patients with diabetes mellitus and current smokers. Using high-resolution ultrasonographic imaging, we evaluated the brachial artery (mm) to evaluate the flow-mediated vasodilation (FMD) by measuring the diameter of the brachial artery during reperfusion after arterial occlusion.

RESULTS

There were no significant differences among the three groups in age (p = 0.98), sex (p = 0.21), or the baseline diameter of the brachial artery (p = 0.11). The group-averaged FMD value decreased significantly in the BRVO group (4.6 ± 0.4%) compared to the hypertension group (8.0 ± 0.8%, p < 0.01) and the healthy group (6.9 ± 0.6%, p < 0.05). Multiple logistic regression analysis identified lower FMD as an independent risk factor for BRVO.

CONCLUSIONS

The results suggested that BRVO is associated with generalized endothelial dysfunction and that impaired systemic endothelial function may be associated with BRVO.

Coronary artery disease, cerebral non-fatal ischemic stroke in retinal vein occlusion: an 8-yr follow-up

Forty-five consecutive subjects (26M, 19F; mean age 54 ± 14 yrs) with a diagnosed retinal vein occlusion (RVO), were followed-up for 8 yrs. As many as 145 sex-age- and blood pressure-matched individuals (78M, 67F; mean age 54.4 ± 13.5 yrs), that did not experience any vascular event, served as controls. At the time of the RVO, controls and subjects did not differ as to hypercholesterolemia, hypertrigliceridemia, diabetes mellitus, smoking habits, inherited/acquired thrombophilia. At the follow-up completion, they differed as to statin consumption (p = 0.016). During the 8-yrs follow-up, in the control population, 11 out of 145 (7.6%) subjects had experienced a major vascular event (8 coronary artery disease; 3 cerebral non-fatal ischemic stroke). In contrast, of the 45 subjects with a history of RVO, as many as 10 (22.2%) had experienced a major vascular event: 4 coronary artery disease; 4 cerebral non-fatal ischemic stroke; 2 cardiovascular + cerebrovascular event (p = 0.012). A prolonged antiplatelet treatment, prior to the major vascular event, was found in 5/45 cases (11.1%) vs 23/145 (15.9%) controls (p = 0.63). In contrast, a long-lasting administration of anti-hypertensive drugs, to achieve a control of blood pressure, was found in 83.4% of controls and only in 46.7% of cases (p < 0.0001). In conclusion, in a 8-yr follow-up, coronary artery disease and/or non-fatal ischemic stroke were more common in subjects with a history of RVO than in a large setting of subjects comparable for cardiovascular risk factors. These data also argue for RVO as a vascular disease in which aggressive anti-hypertensive therapy to prevent stroke and/or myocardial infarction is needed.

Ocular–visual defect and visual neglect in stroke patients – A report from Kathmandu, Nepal

Purpose

To find out the type of visual defects, ocular defects or visual neglect occurring in patients with stroke.

Methods

In this cross-sectional study including 40 subjects diagnosed as stroke, assessment included visual acuity with the Sheridan-Gardner chart, objective and subjective refraction, duction and version eye movement, cover test at distance and near, anterior segment examination with the slit lamp, posterior segment examination after pupil dilatation, color vision test with the Farnsworth D-15 test, diplopia charting, the Hess charting, and visual field examination on Goldmann perimetry. 33 subjects (82.5%) having stroke underwent star cancellation test for visual neglect evaluation. Chi-square test with Yate's correction was performed to evaluate associations between visual neglect and neurological findings.

Results

The mean age of the subjects was 52.1 ± 15.7 years with male/female ratio of 0.7. Neurological findings included hemiplegia/hemiparesis in 84.8%, ischemic stroke in 80%, left hemisphere involvement in 60%, and cortical area involvement in 65%. Ocular finding included extraocular muscle palsy in 17.5%, exotropia in 12.5%, and ptosis in 7.5%. Co-morbid ocular findings such as cataract, retinopathy, and age-related macular degeneration were also reported. Visual neglect was present in 54.5% subjects predominantly affecting the left side.

Conclusion

This study reports the relationship between ocular–visual disorders and stroke. There should be a formal screening for visual problems in stroke patients in hospital and rehabilitation settings.

The burden of disease of retinal vein occlusion: review of the literature

Retinal vein occlusion (RVO) is the second most common cause of vision loss due to retinal vascular disease. A literature review was undertaken to understand the epidemiology, clinical consequence, current practice patterns, and cost of RVO. Pertinent articles were identified by computerized searches of the English language literature in MEDLINE supplemented with electronic and manual searches of society/association proceedings and bibliographies of electronically identified sources. Population-based studies report a prevalence rate of 0.5-2.0% for branch RVO and 0.1-0.2% for central RVO. The 15-year incidence rate is estimated to be 1.8% for branch RVO and 0.2% for central RVO. Patients with RVO report lower vision-related quality of life than those without ocular disease. Available treatment options are limited. Until recently there was no treatment for central RVO. Laser photocoagulation is only recommended for branch RVO in patients who have not experienced severe vision loss. Emerging evidence on the effectiveness of intravitreal anti-vascular endothelial growth factor therapy and dexamethasone intravitreal implant is promising. Information on the treatment patterns and cost of RVO is extremely limited with one retrospective analysis of secondary insurance payment data identified and limited to the United States population only. A better understanding of the economic and societal impact of RVO will help decision makers evaluate emerging medical interventions for this sight-threatening disease.

[SERV clinical practice guidelines: management of retinal vein occlusion. Sociedad Española de Retina y Vitreo]

PURPOSE

A guidelines for the management of retinal vein occlusion is presented. This is necessary because at this moment several therapeutic alternatives have been developed although their role is not yet sufficiently defined.

METHODS

Review of the literature for evidence published up to date. Relevant literature was identified and the level of evidence graded. Evidence was then assessed for consistency, applicability and clinical impact. The information was contrasted with those guides published in other countries.

RESULTS

Taking into account the different options of treatment that are currently used, several modes of action are suggested. The role of the various complementary examinations are discussed and it is recommended that criteria for the treatment are based on clinical, angiographic, and tomographic findings.

CONCLUSIONS

Although there is no overall consensus, these guidelines promote a good standard of clinical practise and provide an update of the management of retinal vein occlusion.

Retinal vein occlusion: an approach to diagnosis, systemic risk factors and management

Retinal vein occlusion (RVO) is the second most common retinal vascular disease after diabetic retinopathy and is a common cause of visual morbidity and blindness in the elderly. A large proportion of patients with RVO have a history of cardiovascular disease, hypertension, diabetes mellitus or open-angle glaucoma. Although RVO is sometimes associated with thrombophilias and coagulation abnormalities, the role of coagulation factors in the development of RVO remains unclear. This review did not find strong evidence to support an extensive work-up for thrombophilic and coagulation diseases for the vast majority of patients. However, when tests for common cardiovascular risk factors for RVO are negative, evaluation for potential coagulation disorders may be indicated, particularly in young patients and in patients with bilateral RVO, a history of previous thromboses or a family history of thrombosis.

Homocysteine, methylenetetrahydrofolate reductase C677T polymorphism, and risk of retinal vein occlusion: a meta-analysis

OBJECTIVE

To assess the role of plasma total homocysteine (tHcy) concentrations and homozygosity for the thermolabile variant of the methylenetetrahydrofolate reductase (MTHFR) C677T gene as risk factors for retinal vascular occlusive disease.

DESIGN

Retinal vein occlusion (RVO) is an important cause of vision loss. Early meta-analyses showed that tHcy was associated with an increased risk of RVO, but a significant number of new studies have been published.

PARTICIPANTS AND/OR CONTROLS

RVO patients and controls.

METHODS

Data sources included MEDLINE, Web of Science, and PubMed searches and searching reference lists of relevant articles and reviews. Reviewers searched the databases, selected the studies, and then extracted data. Results were pooled quantitatively using meta-analytic methods.

MAIN OUTCOME MEASURES

tHcy concentrations and MTHFR genotype.

RESULTS

There were 25 case-control studies for tHcy (1533 cases and 1708 controls) and 18 case-control studies for MTHFR (1082 cases and 4706 controls). The mean tHcy was on average 2.8 micromol/L (95% confidence interval [CI], 1.8-3.7) greater in the RVO cases compared with controls, but there was evidence of between-study heterogeneity (P<0.001, I(2) = 93%). There was funnel plot asymmetry suggesting publication bias. There was no evidence of association between homozygosity for the MTHFR C677T genotype and RVO (odds ratio [OR] 1.20; 95% CI, 0.84-1.71), but again marked heterogeneity (P = 0.004, I(2) = 53%) was observed.

CONCLUSIONS

There was some evidence that elevated tHcy was associated with RVO, but not homozygosity for the MTHFR C677T genotype. Both analyses should be interpreted cautiously because of marked heterogeneity between the study estimates and possible effect of publication bias on the tHcy findings.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Venous and arterial thrombosis: Two aspects of the same disease?

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.