No evidence for thrombophilia in patients with retinal venous occlusion: a systematic GRADE-based review

[Retinal venous occlusion and its association with atherosclerotic vascular disease]

Retinal venous occlusion (RVO) is the second most frequent cause of decreased visual acuity due to retinal vascular, after diabetic retinopathy. Its etiology is not completely clear. Current scientific evidence suggests that it is related to the atherosclerotic process given the high number of cardiovascular risk factors and the higher incidence of cardiovascular events in these patients. In fact, RVO implies a 45% higher risk of stroke, 26% of acute myocardial infarction and peripheral vascular disease, 53% of heart failure and 36% of overall mortality, compared to the general population adjusted for age, sex and the different cardiovascular risk factors. However, no increase in cardiovascular mortality has been detected. Therefore, a multidisciplinary clinical approach to this pathology is essential.

[Internistic clarification of retinal vascular occlusions]

Retinal vascular occlusions require close cooperation of different medical disciplines to ensure optimal care of the affected patients. The medical clarification between arterial and venous occlusions is comparable but in the case of retinal arterial occlusions it should be carried out immediately. The most important associated diagnoses are arterial hypertension, diabetes mellitus, dyslipidemia, and atrial fibrillation. In younger patients and in the absence of risk factors, a search for rarer causes should be carried out giant cell arteritis in particular should be excluded. In both types of occlusions a causative glaucoma must also be considered.

Hypercoagulability Testing and Hypercoagulable Disorders in Young Central Retinal Vein Occlusion Patients

PURPOSE

To determine frequency of hypercoagulability testing and hypercoagulable states in patients with central retinal vein occlusion (CRVO) younger than 50 years.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Deidentified patients younger than 50 years with newly diagnosed CRVO from a national insurance claims database.

METHODS

The de-identified Clinformatics Data Mart Database (Optum) containing medical claims from a commercial and Medicare Advantage insurance database was used. All outpatient medical claims (office visits, associated diagnoses, and laboratory testing) and demographic data for each beneficiary during their enrollment were accessible.

MAIN OUTCOME MEASURES

Prevalence of (1) laboratory hypercoagulable workup within 90 days of CRVO diagnosis, (2) new diagnosis of a hypercoagulable state within 1 year of CRVO diagnosis, and (3) diagnosis of hypertension, diabetes mellitus (DM), and hyperlipidemia.

RESULTS

One thousand one hundred eighty-one patients met inclusion criteria. Six hundred seventy-one patients (56.8%) were men, 450 patients (38.1%) had undergone hypercoagulable testing within 90 days, and 136 patients (11.5%) were diagnosed with a hypercoagulable state within 1 year after CRVO diagnosis. This proportion was similar between those patients with DM, hypertension, or hyperlipidemia (10.5% [65/620]) and those without (12.7% [71/561]; P = 0.28). Of the 136 patients diagnosed with a hypercoagulability state, 68.4% (93/136) had undergone testing within 90 days of CRVO diagnosis and 31.6% (43/136) did not. Of those who had not undergone hypercoagulability testing, 5.9% (43/731) were diagnosed with a hypercoagulable state within 1 year compared with 20.7% (93/450) in those who were tested (P < 0.001).

CONCLUSIONS

The prevalence of a hypercoagulable state within 1 year of CRVO diagnosis in patients younger than 50 years was 11.5%, and the prevalence was similar between patients with atherosclerotic risk factors and those without. Rate of testing was only 38.1%. Future research should examine the usefulness of uniform hypercoagulable testing in young CRVO patients.

Severe Protein C Deficiency due to Novel Biallelic Variants in PROC and Their Phenotype Correlation

Severe protein C deficiency due to biallelic PROC mutations is an extremely rare thrombophilia, most commonly presenting during the neonatal period as purpura fulminans. Despite treatment, severe morbidity and mortality are frequent. The current study reports 3 unrelated patients harboring novel homozygous PROC mutations and their clinical phenotypes. We discuss how the cytoprotective activity of protein C and its role in the stabilization of endothelial barriers may account for the unique symptoms of this thrombophilia.

Hypertension and multiple cardiovascular risk factors increase the risk for retinal vein occlusions: results from the Gutenberg Retinal Vein Occlusion Study

OBJECTIVE

Although several risk factors for retinal vein occlusion (RVO) are known, what triggers RVO is unclear in many cases. We aimed to evaluate the relevance of multiple risk factors in patients with RVO.

METHODS

The Gutenberg RVO Study is an observational case-control study that assessed thrombophilic, cardiovascular, ophthalmic, and drug-related risk factors in participants with RVO and the same number of matched controls. Conditional logistic regression analysis was chosen to estimate the risk of RVO due to several risk factors.

RESULTS

Of 92 patients with RVO, 46 (50%) had central RVO, 31 (33.7%) had branch RVO, and 15 (16.3) had hemi-RVO. Systemic hypertension was associated with RVO [any RVO: odds ratio (OR): 1.81; 95% confidence interval (CI): 1.14-2.88; branch RVO: OR: 2.56; 95% CI: 1.08-6.10]. The most frequent combinations of risk factors were hypertension with dyslipidemia (33 of 92, 35.9%) and hyperhomocysteinemia and high levels of factor VIII (10 of 92, 10.9%). An increase in the risk sum score by one additional risk factor corresponded to ORs of 1.74 (95% CI: 1.31-2.32) for cardiovascular risk factors, 1.38 (95% CI: 1.04-1.82) for thrombophilic risk factors, and 1.43 (95% CI: 1.20-1.70) for the total number of risk factors for RVO.

CONCLUSION

Cardiovascular risk factors are more important than other risk factors for the presence of RVO. The risk of RVO increased by approximately 40% with any additional risk factor and by 70% with any additional cardiovascular risk factor.

Antiphospholipid syndrome and antiphospholipid antibody profile in patients with retinal vein occlusion

INTRODUCTION

Data on prevalence, association with vascular risk factors, clinical management and outcome of antiphospholipid syndrome (APS) in retinal vein occlusion (RVO) are scarce.

METHODS

Patients diagnosed with RVO at a tertiary-care hospital, and two additional groups; population-based controls and patients with APS (RVO-APS) were studied. Prevalence, association with vascular risk factors, antiphospholipid antibody profile, clinical management, genetic thrombophilia profile, carotid ultrasound and outcome of RVO-APS patients were assessed and compared with controls.

RESULTS

Some 331 consecutive patients with RVO and 281 controls were included. Overall, aPLs were more prevalent in RVO-patients than in controls (33, 10% vs. 12, 4.3%; adjusted OR 2.47; 95% CI 1.25-4.88; p = 0.009). Patients with RVO-APS showed a high-risk "aPL profile" (lupus anticoagulant or triple-positive). We did not find any difference regarding classic vascular risk factors, hyperhomocysteinemia, prior vascular events, and carotid plaque, in RVO-patients with or without APS. The phenotype of RVO-APS also differed from APS. Seven patients received anticoagulation and 24 were on low-dose aspirin. After a median follow-up of 62 months, 7 patients suffered a RVO relapse (4 of them had APLs) and no RVO-APS patient had a new thrombotic or vascular event outside the retina.

CONCLUSIONS

aPLs were more prevalent in RVO-patients than in controls, and in all patients, APS was not associated with any connective-tissue disease. RVO in the setting of APS seems not only related to atherosclerosis, but also to the "aPL profile". In most of our RVO-patients with APS, low-dose aspirin was effective to prevent new or recurrent thrombotic events outside the retinal vessels. In these patients, we suggest that RVO could behave as an organ-specific manifestation of APS.

Thrombophilic risk factors for retinal vein occlusion

The aim is to study risk factors for retinal vein occlusion (RVO), such as thrombophilic and cardiovascular risk factors (CRF). A retrospective consecutive case series of 60 patients with RVO was made, tested for CRF, hyperhomocysteinemia, lupic anticoagulant, antiphospholipid antibody and 5 gene variants: factor V (FV) Leiden (G1691A), factor II (PT G20210A), 5,1-methylenetetra-hydrofolate reductase (MTHFR; 677 C > T and 1298 A > C), plasminogen activator inhibitor 1 (PAI-1; 4 G/5 G). More than 1 CRF were present in 36 patients (60%), which had a significantly higher mean age at diagnosis (66.7 ± 12.9 versus 59.5 ± 13.7 with ≤1 CRF, [t(57) = −2.05, p = 0.045, d = 0.54). Patients with thermolabile MTHFR forms with decreased enzyme activity (T677T or C677T/A1298C) had a significant lower mean age [57.6 ± 15.1; t (58) = 3.32; p = 0.002; d = 0.846] than patients with normal MTHFR enzyme activity (68.5 ± 10.2). Regarding CRF and thermolabile forms of MTHFR, the mean age at diagnosis could be significantly predicted [F(2,56) = 7.18; p = 0.002] by the equation: 64.8 − 10.3 × (thermolabile MTHFR) − 5.31 × ( ≤ 1CRF). Screening of MTHFR polymorphisms may be useful in younger RVO patients, particularly when multiple CRF are absent.

Elevation of serum oxidative stress in patients with retina vein occlusions

PURPOSE

Retina vein occlusion (RVO) is a visual-threatening retinal disease that causes irreversible impaired quality of life. The contribution of oxidative stress behind clinical course of RVO was rarely investigated. The study aimed to measure the serum oxidative biomarker in patients with RVO to investigate further physical response.

METHODS

We measured the serum levels of malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8OHdG), Sirutin 1 (SIRT1), peroxisome proliferator- activated receptor gamma (PPAR-r), Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), orkhead box protein O1 (FOXO1), orkhead box protein O3 (FOXO3), catalase, (SOD) and hydrogen peroxide (H₂ O₂ ) among 19 patients with cataract as control group and 36 patients with RVO, respectively.

RESULTS

The mean MDA, 8OHdG and hydrogen peroxide in the serum were significantly higher in patients with RVO compared with the results in control group subjects. Whereas SIRT1, PPAR-r, PGC-1, FOXO1, FOXO3, catalase and SOD levels in serum were significantly decreased in patients with RVO compared with control group.

CONCLUSION

We demonstrated that the serum level of MDA, 8OHdG and hydrogen peroxide is increased in patients with RVO. Among these, the elevation of MDA, 8OHdG and hydrogen peroxide suggests the increasing of serum oxidative stress in RVO patients. All enzymes related reactive oxygen species scavenge were decreased. Thus, focal RVO may increase systemic oxidative stress within serum.

Can Rotational Thromboelastometry be a New Predictive Tool for Retinal Vein Occlusion Development?

PURPOSE

To evaluate clotting dynamics by a new tool called rotational tromboelastometry (ROTEM) in retinal vein occlusion.

MATERIALS AND METHODS

Thirty-six patients who were diagnosed with retinal vein occlusion and 43 age and sex matched healthy controls were included in this study. Diabetes and use of anticoagulant therapy were exclusion criteria. All study participants underwent detailed ophthalmologic and systemic medical examination, including blood pressure measurement, hemoglobin-hematocrit levels, platelet count, coagulation parameters including prothrombin time, activated partial thromboplastin time, fibrinogen levels, and D-dimer levels. Peripheral blood samples were collected and analyzed with ROTEM Coagulation Analyzer (Tem International, Munich, Germany).

RESULTS

The RVO patients and controls did not differ with respect to age, sex, hemoglobin, hematocrit, platelet numbers, prothrombin time, activated partial thromboplastin time, fibrinogen levels, D-dimer levels, and glucose levels. When extrinsic thromboelastometry results were analyzed, RVO patients showed a significantly decreased clotting time (76.5 ± 15.0 vs. 95.0 ± 21 s, respectively; p = 0.01) and clot formation time (83.3 ± 22 vs. 99.7 ± 24s; p = 0.01) as compared with healthy controls. Other ROTEM parameters did now show any difference between two groups.

CONCLUSION

Patients with retinal vein occlusion showed faster clotting time and shorter clotting formation time as compared with healthy controls. ROTEM detects the altered clotting dynamics and may be a useful tool to elucidate the disease pathophysiology. Further studies are needed to investigate if it can be used as a screening test for individuals who are under risk to develop RVO or as a first step test to evaluate hypercoagulable state in RVO.

Correlation between retinal vein occlusion and cancer - a nationwide Danish cohort study

PURPOSE

To explore the association between retinal vein occlusion (RVO) and incident cancer.

METHODS

All Danish citizens with a first-time diagnosis of RVO and no previous diagnosis of cancer in the period from 1 January 2004 to 31 December 2014 were included. Five likewise cancer-free, age- and gender-matched controls were included in a control cohort. All were followed up for 5 years or until either first diagnosis of cancer or death. Proportional hazards models with adjustment for age, gender, year of diagnosis and covariates and death as competing risk were used to estimate the risk of being diagnosed with cancer.

RESULTS

There were 7963 RVO patients without cancer at the time of diagnosis, and all could be matched to likewise cancer-free controls. Half of RVO patients were male, and the median age at RVO diagnosis was 70 years (61-79). The control cohort was similar in terms of gender and age. The risk of cancer within 1 year was 1.8 among RVO patients and 1.5 among controls. The crude risk of cancer was 1.22 (1.11;1.34) and upon full adjustment 1.15 (1.05;1.27). No time dependency was detected, and the types of cancer developed in RVO patients and controls were similar.

CONCLUSION

Retinal vein occlusion (RVO) diagnosis is associated with an increased risk of being diagnosed with cancer. This risk is likely to reflect shared risk factors rather than a causal association.

Thrombophilic and cardiovascular risk factors for retinal vein occlusion

BACKGROUND

The role of thrombophilic and cardiovascular risk factors in different manifestations of retinal vein occlusion (RVO), i.e., central or branch RVO, and at different ages is still debated.

AIMS

To evaluate the association between thrombophilic and cardiovascular risk factors and the risk of RVO (overall, separately for central and branch RVO, and at different ages).

METHODS

Case-control study on 313 patients with a first objectively-confirmed RVO (216 central and 97 branch RVO) and 415 healthy individuals.

RESULTS

Antithrombin, protein C or protein S deficiency (adjusted odds ratio [95%CI]: 15.60 [2.01-121]; p=0.009), hyperhomocysteinemia (HHCy; 3.22 [1.38-7.49]; p=0.007), high factor VIII (FVIII) levels (3.08 [1.20-7.89]; p=0.019), factor V Leiden (2.93 [0.97-8.86]; p=0.058) and the presence of at least one cardiovascular risk factor (1.79 [1.00-3.23]; p=0.050) were associated with an increased risk of branch RVO. The association was weaker for central RVO, and limited to HHCy (2.15 [1.09-4.24]; p=0.027) and high FVIII (1.99 [0.90-4.42]; p=0.091). For HHCy, high FVIII and cardiovascular risk factors the association with the risk of RVO was stronger at an age>50years (3.41[1.29-8.99], p=0.013; 2.57[1.00-6.68], p=0.050; and 2.03[1.16-3.56], p=0.013, respectively) than ≤50years (1.93[0.85-4.36], p=0.114; 1.67[0.54-5.12], p=0.371; and 1.22[0.73-2.03], p=0.454, respectively), whereas classic inherited thrombophilia (antithrombin, protein C or protein S deficiencies, factor V Leiden and prothrombin G20210A mutation) was slightly more prevalent at an age≤50years (1.62 [0.76-3.45], p=0.210) than >50years (1.11[0.44-2.79], p=0.833).

CONCLUSIONS

Thrombophilic and cardiovascular risk factors are associated with RVO, particularly branch RVO. The risk of RVO associated with HHCy, high FVIII and cardiovascular risk factors is higher at an older age.

Retinal vein occlusion and paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder associated with increased risk for thrombosis and reduced life expectancy. Retinal vein occlusion (RVO) is a frequent cause of vision loss but its relationship with PNH has not been studied systematically. Patients followed up for RVO in our ophthalmology department were screened for the presence of a PNH clone in peripheral blood by means of flow cytometry. The presence of other well-documented risk factors for RVO was also analyzed. In a series of 110 patients (54 males, median age of 67) we found no evidence of PNH. Most patients (97/110) had cardiovascular risk factors and/or hyperhomocysteinemia (67/110). Inherited thrombophilias were rare (three confirmed cases). Therefore, PNH does not appear to play a role in the development of RVO. However, this finding does not necessarily apply to young patients and/or those with no conventional risk factors for RVO, due to the low number of patients in these subgroups in our population.