Atherosclerotic and thrombophilic risk factors in patients with ischemic central retinal vein occlusion

Nutritional Factors: Benefits in Glaucoma and Ophthalmologic Pathologies

Glaucoma is a chronic optic neuropathy that can lead to irreversible functional and morphological damage if left untreated. The gold standard therapeutic approaches in managing patients with glaucoma and limiting progression include local drops, laser, and/or surgery, which are all geared at reducing intraocular pressure (IOP). Nutrients, antioxidants, vitamins, organic compounds, and micronutrients have been gaining increasing interest in the past decade as integrative IOP-independent strategies to delay or halt glaucomatous retinal ganglion cell degeneration. In our minireview, we examine the various nutrients and compounds proposed in the current literature for the management of ophthalmology diseases, especially for glaucoma. With respect to each substance considered, this minireview reports the molecular and biological characteristics, neuroprotective activities, antioxidant properties, beneficial mechanisms, and clinical studies published in the past decade in the field of general medicine. This study highlights the potential benefits of these substances in glaucoma and other ophthalmologic pathologies. Nutritional supplementation can thus be useful as integrative IOP-independent strategies in the management of glaucoma and in other ophthalmologic pathologies. Large multicenter clinical trials based on functional and morphologic data collected over long follow-up periods in patients with IOP-independent treatments can pave the way for alternative and/or coadjutant therapeutic options in the management of glaucoma and other ocular pathologies.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second most prevalent retinal disease. Despite this, the pathogenic mechanisms and risk factors are not entirely clear. In this article, we review recent publications on the classification, pathogenesis, risk factors, ischemic changes, cytokines, and vital complications of RVO. Risk factors and cytokines are important for exploring the mechanisms and new treatment targets. Furthermore, risk factors are interrelated, making RVO mechanisms more complex. Cytokines act as powerful mediators of pathological conditions, such as inflammation, neovascularization, and macular edema. This review aims to summarize the updated knowledge on risk factors, cytokines of RVO and signaling in order to provide valuable insight on managing the disease.

Comparison of each retinal layer thicknesses between eyes with CRVO and normal contralateral eyes

Purpose

To evaluate the difference in each retinal layer thickness in central retinal vein occlusion (CRVO) with resolved macular edema after intravitreal antivascular endothelial growth factor injection and normal contralateral eyes..

Methods

Patients with ischemic and nonischemic CRVO whose macular edema resolved after intravitreal antivascular endothelial growth factor injections and did not recur for at least 6 months, and a normal contralateral eye were enrolled. Each retinal layer thickness between CRVO and normal contralateral eyes was compared according to Early Treatment Diabetic Retinopathy Study subfields using spectral domain optical coherence tomography.

Results

The thicknesses of outer nuclear layer, photoreceptor layer, and retinal pigment epithelium in central ring, ganglion cell layer, inner plexiform layer, outer nuclear layer, and photoreceptor layer in the inner ring, and ganglion cell layer in the outer ring of CRVO eyes were significantly thinner than those of normal contralateral eyes (all p < 0.05). Whereas, inner nuclear layer and outer plexiform layer thicknesses in central ring of CRVO eyes were 23.86 ± 8.8 and 25.76 ± 7.6 μm, respectively, which was significantly thicker than those of normal contralateral eyes (19.52 ± 7.7 and 22.76 ± 6.5 μm; p = 0.019 and p = 0.043, respectively). Additionally, the mean best-corrected visual acuity of CRVO eyes were significantly correlated with photoreceptor layer thickness in central ring (p = 0.005).

Conclusions

In CRVO eyes with resolved macular edema, the outer retinal layers were thinner as well as inner retinal layers, whereas inner plexiform layer and outer nuclear layer were thicker than normal fellow eyes. Additionally, photoreceptor layer thickness in foveal area had a significant impact on visual acuity in CRVO.

A review on clotting disorders and retinal hemorrhages: Can they mimic abuse?

BACKGROUND

The characteristic findings of abusive head trauma (AHT) include retinal hemorrhages (RH). RH have many etiologies in childhood, which should be considered in the differential diagnosis of possible child abuse. The relationship between RH and thrombophilia in children is not well established.

OBJECTIVE

In this literature review, we sought to assess whether retinal findings in pediatric patients with thrombophilia could mimic those of AHT.

METHODS

A literature search was performed to identify all cases of thrombophilia in children less than 18 years old with ocular manifestations. Disorders of thrombophilia including protein C and S deficiency, factor V Leiden (FVL), prothrombin variant, MTHFR mutation, hyperhomocysteinemia, elevated factor VIII, and elevated lipoprotein (a) were considered. All cases of pediatric thrombophilia with retinal examination or intraocular bleeding were included. If provided, descriptions of the RH were reviewed.

RESULTS

Our initial search yielded 514 results. Forty-three articles met our inclusion criteria. We identified 3 children with RH within the AHT usual age range (<5 years old), ages 5 weeks and 7 weeks old, in the setting of thrombophilia. One child had ocular findings that could potentially mimic abuse. No other indicators of abuse were present in this case.

CONCLUSIONS

Based on previous reports, thrombophilia alone has not been shown to clearly mimic abusive head trauma. In reported cases of thrombophilia with RH, the clinical picture and ophthalmic findings are usually distinct from abuse.

Screening for obstructive sleep apnea amongst patients with retinal vein occlusion

OBJECTIVE

To evaluate the prevalence and varying severity of obstructive sleep apnea (OSA) amongst those newly diagnosed with retinal vein occlusion (RVO), and screen patients with the use of 2 in-office-administered questionnaires validated against polysomnography.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Consecutive adult patients (≥18 years of age) with a new diagnosis of RVO confirmed with intravenous fluorescein angiography were enrolled.

METHODS

The study was conducted at a tertiary academic centre between March 22, 2017, and April 7, 2018. Patients completed the Berlin and STOP-BANG questionnaires screening for OSA at presentation. Diagnostic test properties of the 2 questionnaires compared with polysomnography at a certified sleep laboratory centre as the gold standard for detection of OSA were calculated.

RESULTS

A total of 27 patients (37% females) with a mean (standard deviation) age of 69.6 (11.5) years completed the study. The diagnosis of OSA based on polysomnography was made in 96% (41% severe OSA) of patients with RVO. The Berlin questionnaire had a sensitivity of 43% (confidence interval [CI]: 22%-66%) and specificity of 67% (CI: 22%-96%). The STOP-BANG questionnaire had a sensitivity of 86% (CI: 64%-97%) and specificity of 50% (CI: 12%-88%).

CONCLUSIONS

Given the high prevalence of severe OSA amongst those with a new diagnosis of RVO, all patients should be strongly considered for polysomnography. The use of in-office questionnaires may aid in triaging urgency of referrals.

Risk of Ischemic Stroke, Hemorrhagic Stroke, and All-Cause Mortality in Retinal Vein Occlusion: A Nationwide Population-Based Cohort Study

Purpose

To investigate whether the risk of subsequent stroke, ischemic stroke, hemorrhagic stroke, and all-cause mortality is increased among retinal vein occlusion (RVO) patients compared to non-RVO patients.

Methods

From the entire population of the Taiwan National Health Insurance Research Database (NHIRD) from 2001 to 2013, a total of 22919 subjects with RVO were enrolled in the RVO group, and 114595 propensity score (PS)-matched non-RVOs were enrolled in the comparison group. PS matching was based on age, gender, obesity, diabetes, hypertension, hyperlipidemia, coronary artery disease, atrial fibrillation, hyperviscosity syndrome, Charlson comorbidity index, glaucoma, and the use of antithrombotic drugs. A multivariate Cox regression analysis was used to estimate the adjusted hazard ratios (HRs) with a 95% confidence interval (CI) for each of the clinical outcomes, including stroke, ischemic stroke, hemorrhagic stroke, and all-cause mortality. Furthermore, we divided the RVO group into the branch retinal vein occlusion (BRVO) group and the central retinal vein occlusion (CRVO) group and separately compared their subsequent risks of the clinical outcomes with those of the comparison group.

Results

After adjusting for PS, the RVO group had a significantly higher risk of stroke (adjusted HR = 1.36; 95% CI: 1.32–1.40), ischemic stroke (adjusted HR = 1.36; 95% CI: 1.32–1.40), and hemorrhagic stroke (adjusted HR = 1.34; 95% CI: 1.24–1.44). However, the all-cause mortality did not exhibit significant differences. Furthermore, both the BRVOs and CRVOs had a significantly higher risk of subsequent stroke, ischemic stroke, and hemorrhagic stroke than did the comparisons, whereas all-cause mortality was similar among the groups.

Conclusions

People with RVO are at a significantly greater risk of developing stroke, ischemic stroke, and hemorrhagic stroke. However, RVO does not significantly increase the risk of all-cause mortality.

Increased Fibrinogen to Albumin Ratio in Ischemic Retinal Vein Occlusions

Purpose

To demonstrate the relationship between ischemia and plasma fibrinogen and serum albumin levels in cases of retinal vein occlusion (RVO).

Methods

This study included 44 patients with central RVO (CRVO), 68 patients with branch RVO (BRVO), and 54 age- and sex-matched controls, for a total of 166 subjects. All of the subjects underwent full ophthalmologic examinations and complete physical examinations, including a detailed medical history and blood count, and biochemical parameters.

Results

The mean fibrinogen to albumin ratios were 92.5 ± 36.1 for the patients with CRVO, 84.5 ± 31.5 for the patients with BRVO, and 68.4 ± 12.2 for the control group. Overall, the patients with CRVO and patients with BRVO with ischemia had higher fibrinogen to albumin ratios and higher fibrinogen levels. Moreover, significant positive correlations were found between ischemia and the fibrinogen to albumin ratio (r = 0.732, p = 0.001) and the fibrinogen level (r = 0.669, p = 0.001).

Conclusions

The fibrinogen to albumin ratio is significantly associated with ischemic RVO. Instead of complicated and invasive methods, such as a retinal angiogram, the fibrinogen to albumin ratio could be a useful initial diagnostic test to predict ischemia in RVO.

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.

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.

Increased expression of angiogenic and inflammatory proteins in the vitreous of patients with ischemic central retinal vein occlusion

Background

Central retinal vein occlusion (CRVO) is a common disease characterized by a disrupted retinal blood supply and a high risk of subsequent vision loss due to retinal edema and neovascular disease. This study was designed to assess the concentrations of selected signaling proteins in the vitreous and blood of patients with ischemic CRVO.

Methods

Vitreous and blood samples were collected from patients undergoing surgery for ischemic CRVO (radial optic neurotomy (RON), n = 13), epiretinal gliosis or macular hole (control group, n = 13). Concentrations of 40 different proteins were determined by an ELISA-type antibody microarray.

Results

Expression of proteins enriched in the vitreous (CCL2, IGFBP2, MMP10, HGF, TNFRSF11B (OPG)) was localized by immunohistochemistry in eyes of patients with severe ischemic CRVO followed by secondary glaucoma. Vitreal expression levels were higher in CRVO patients than in the control group (CRVO / control; p < 0.05) for ADIPOQ (13.6), ANGPT2 (20.5), CCL2 (MCP1) (3.2), HGF (4.7), IFNG (13.9), IGFBP1 (14.7), IGFBP2 (1.8), IGFBP3 (4.1), IGFBP4 (1.7), IL6 (10.8), LEP (3.4), MMP3 (4.3), MMP9 (3.6), MMP10 (5.4), PPBP (CXCL7 or NAP2) (11.8), TIMP4 (3.8), and VEGFA (85.3). In CRVO patients, vitreal levels of CCL2 (4.2), HGF (23.3), IGFBP2 (1.23), MMP10 (2.47), TNFRSF11B (2.96), and VEGFA (29.2) were higher than the blood levels (vitreous / blood, p < 0.05). Expression of CCL2, IGFBP2, MMP10, HGF, and TNFRSF11B was preferentially localized to the retina and the retinal pigment epithelium (RPE).

Conclusion

Proteins related to hypoxia, angiogenesis, and inflammation were significantly elevated in the vitreous of CRVO patients. Moreover, some markers known to indicate atherosclerosis may be related to a basic vascular disease underlying RVO. This would imply that local therapeutic targeting might not be sufficient for a long term therapy in a systemic disease but hypothetically reduce local changes as an initial therapeutic approach.

Risk Factors and Treatment Strategies in Patients With Retinal Vascular Occlusions

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.

Regional morphology and pathophysiology of retinal vascular disease

Disturbances in the retinal vascular supply are involved in the pathophysiology of the most frequent diseases causing visual impairment and blindness in the Western World. These diseases are diagnosed by noting how morphological lesions in the retina vary in shape, size, location and dynamics, and subsequently concluding the presence of a specific disease entity. This diagnostic approach can be used to identify the site of a retinal vascular occlusion, to assess whether retinal diseases are primarily due to changes in the larger retinal vessels or the microcirculation, and to differentiate the relative involvement of the choroidal and the retinal vascular systems. However, a number of morphological manifestations of retinal vascular disease cannot presently be related to the underlying pathophysiology. The review concludes that there is a need for developing new methods for assessing vascular structure and function in the ciliary vascular system supplying the choroid and the optic nerve head. Presently, the study of these structures relies on imaging techniques with limited penetration and resolution into the tissue. Secondly, there is a need for studying oscillations in retinal vascular function occurring within days to weeks, and for studying regional manifestations of retinal vascular disease. This may constitute the basis for future research in retinal vascular pathophysiology and for the development of new treatment modalities to reduce blindness secondary to retinal vascular disease.

Impact of arterial hypertension on the eye

Systemic hypertension has been linked to a wide range of major eye diseases. High arterial blood pressure (BP) decreases choroidal circulatory flow, increases intraocular pressure, and is associated with retinal microvascular abnormalities and prevalence of retinal vein occlusion (RVO) and retinopathy. This review offers a comprehensive overview of ocular diseases associated with hypertension and emphasizes their importance as predictors to future cardiovascular events. It also gives evidence-based clinical data for the therapeutic approach of eye disease in hypertensive patients.

Therapeutic potential of intravitreal pharmacotherapy in retinal vein occlusion

Retinal vein occlusion (RVO) is the most common visually disabling disease affecting the retina after diabetic retinopathy. Although the disease entity has long been known, its management is still controversial. Macular edema is the main reason for decreased visual acuity (VA) in this retinal vascular disorder. Recently the vitreous cavity has increasingly been used as a reservoir of drugs for the direct treatment of macular edema through intravitreal injection route. The most widely injected drugs so far have been triamcinolone acetonide (TA) and bevacizumab. The objective of this review is to evaluate the evidence and discuss the rationale behind the recent suggestions that intravitreal pharmacotherapy by corticosteroids and anti-vascular endothelial growth factors may be useful in the treatment of retinal vein occlusion.

A longitudinal analysis of risk factors associated with central retinal vein occlusion

PURPOSE

To identify risk factors associated with central retinal vein occlusion (CRVO) among a diverse group of patients throughout the United States.

DESIGN

Longitudinal cohort study.

PARTICIPANTS

All beneficiaries aged ≥ 55 years who were continuously enrolled in a managed care network for at least 2 years and who had ≥ 2 visits to an eye care provider from 2001 to 2009.

METHODS

Insurance billing codes were used to identify individuals with a newly diagnosed CRVO. Multivariable Cox regression was performed to determine the factors associated with CRVO development.

MAIN OUTCOME MEASURES

Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) of being diagnosed with CRVO.

RESULTS

Of the 494 165 enrollees who met the study inclusion criteria, 1302 (0.26%) were diagnosed with CRVO over 5.4 (± 1.8) years. After adjustment for known confounders, blacks had a 58% increased risk of CRVO compared with whites (HR, 1.58; 95% CI, 1.25-1.99), and women had a 25% decreased risk of CRVO compared with men (HR, 0.75; 95% CI, 0.66-0.85). A diagnosis of stroke increased the hazard of CRVO by 44% (HR, 1.44; 95% CI, 1.23-1.68), and hypercoagulable state was associated with a 145% increased CRVO risk (HR, 2.45; 95% CI, 1.40-4.28). Individuals with end-organ damage from hypertension (HTN) or diabetes mellitus (DM) had a 92% (HR, 1.92; 95% CI, 1.52-2.42) and 53% (HR, 1.53; 95% CI, 1.28-1.84) increased risk of CRVO, respectively, relative to those without these conditions.

CONCLUSIONS

This study confirms that HTN and vascular diseases are important risk factors for CRVO. We also identify black race as being associated with CRVO, which was not well appreciated previously. Furthermore, we show that compared with patients without DM, individuals with end-organ damage from DM have a heightened risk of CRVO, whereas those with uncomplicated DM are not at increased risk of CRVO. This finding may provide a potential explanation for the conflicting reports in the literature on the association between CRVO and DM. Information from analyses such as this can be used to create a risk calculator to identify possible individuals at greatest risk for CRVO.

Thrombophilia and retinal vascular occlusion

Purpose

The purpose of this research was to assess associations of thrombophilia with central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), and amaurosis fugax (AF); to evaluate outcomes of normalizing high homocysteine; and to study CRVO, CRAO, and AF developing in estrogens/estrogen agonists in women subsequently shown to have thrombophilia.

Methods

Measures of thrombophilia–hypofibrinolysis were obtained in 132 CRVO cases, 15 CRAO cases, and 17 AF cases. Cases were compared to 105 healthy control subjects who did not differ by race or sex and were free of any ophthalmologic disorders. All cardiovascular disease (CVD) risk factors were compared to healthy general populations.

Main outcome measures

The main outcome measure of this study was thrombophilia.

Results

CRVO cases were more likely than controls to have high homocysteine (odds ratio [OR] 8.64, 95% confidence intervals [CI]: 1.96–38), high anticardiolipin immunoglobulin M (IgM; OR 6.26, 95% CI: 1.4–28.2), and high Factor VIII (OR 2.47, 95% CI: 1.31–7.9). CRAO-AF cases were more likely than controls to have high homocysteine (OR 14, 95% CI: 2.7–71.6) or the lupus anticoagulant (OR 4.1, 95% CI: 1.3–13.2). In four of 77 women with CRVO (two found to have high homocysteine, two with inherited high Factor XI), CRVO occurred after starting estrogen–progestins, estrogen–testosterone, or estrogen agonists. In one of eight women with CRAO found to have high anticardiolipin antibody IgG, CRAO occurred after starting conjugated estrogens, and AF occurred after starting conjugated estrogens in one of eleven women with AF (inherited protein S deficiency). Therapy for medians of 21 months (CRVO) and 6 months (CRAO-AF) was 5 mg folic acid, 100 mg B6, and 2000 mcg/day B12 normalized homocysteine in 13 of 16 (81%) CRVO cases and all five CRAO-AF cases with pretreatment hyperhomocysteinemia. The CRVO cases had an excess of hypertension; CRAO-AF cases had an excess of type 2 diabetes and hypertension.

Conclusion

Treatable thrombophilia, hyperhomocysteinemia in particular, is more common in RVO cases than in normal controls. RVO occurs after estrogens or estrogen agonists were administered in women subsequently shown to have thrombophilia.