Hyperhomocysteinemia in central retinal vein occlusion in young adults

Prevention and Treatment of Retinal Vein Occlusion: The Role of Diet-A Review

Retinal vein occlusion (RVO) is the second most common retinal disorder. In comparison to diabetic retinopathy or age-related macular degeneration, RVO is usually an unexpected event that carries a greater psychological impact. There is strong evidence to suggest that cardiovascular diseases are the most common risk factors in this pathology and it has long been known that a higher consumption of fish, nuts, fruits, and vegetables has a protective effect against these types of conditions. In the last several years, interest in plant-based diets has grown in both the general population and in the scientific community, to the point to which it has become one of the main dietary patterns adopted in Western countries. The aim of this review is to investigate the potential impact of macro- and micronutrients on retinal vein occlusion.

Clinical Features of Central Retinal Vein Occlusion in Young Patients

Retinal vein occlusion (RVO) is the second most common retinal vascular disease. Central RVO (CRVO), in which obstruction occurs posterior to the lamina cribrosa due to various causes, manifests with extensive venous tortuosity, dilatation of blood vessels in the four quadrants, and retinal hemorrhage. The presence of macular edema decreases visual acuity in patients with CRVO, especially in elderly patients with hypertension, hyperlipidemia, and diabetes. In the last decade, treatment modalities for CRVO have improved, with anti-vascular endothelial growth factor agents being widely used as treatment. However, there are cases of refractory or recurrent macular edema. Moreover, CRVO also occurs in young patients. This article reviews previous studies and case reports and summarizes the differences in etiological factors, clinical manifestations, treatment, and prognosis between young and elderly patients. Due to the low incidence of CRVO in young patients, clinical data from these age groups are limited. Hence, further studies are warranted to explore the differences between age groups to improve individualization of treatment of young patients.

Methylenetetrahydrofolate reductase polymorphisms as risk factors for retinal venous occlusive disease: A literature review

The role of polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene in retinal vein occlusion (RVO) is a theme of discussion since the first reports of RVO in patients with MTHFR C677T mutation and without classic acquired risk factors for retinal vascular disease. The association between MTHFR polymorphisms and RVO has been studied over the last 20 years producing conflicting results. This review aims to summarize the literature concerning the role MTHFR polymorphisms as risk factors for RVO.

Central retinal venous occlusion in a child with hyperhomocysteinemia: A case report

RATIONALE

To report a rare case of 8-year-old girl patient with central retinal venous occlusion (CRVO) with hyperhomocysteinemia.

PATIENT CONCERNS

The patient had a 2-year history on painless visual loss in the left eye.

DIAGNOSES

All examination results were within normal limits except plasma homocysteine (HCY). Fluorescein angiography (FA) confirmed peripheral capillary non-perfusion (CNP) in the left eye, and OCT showed macular edema. The girl patient was diagnosed as CRVO.

INTERVENTIONS

Based on all of the test results, laser photocoagulation was performed at peripheral capillary non-perfusion (NP). Ranibizumab was injected into virtreous cavity to reduce the macular edema. Oral folic acid, vitamin B12, and vitamin B6 were performed to the girl.

OUTCOMES

After 13 months, the girl visual acuity recovered to 20/100 in the left eye.

LESSONS

All eye examinations should be performed in young patients, and they should undergo treatments immediately after is diagnosed as CRVO.

End Stage Renal Disease as a Potential Risk Factor for Retinal Vein Occlusion

End stage renal disease (ESRD) has been reported to be an important risk factor for systemic vascular disease. Retinal vein occlusion (RVO) is closely related with cardiovascular diseases; however, its association with ESRD had not been reported. The aim of the study was to investigate whether ESRD is a risk factor for RVO, including central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). This population-based study is based on the longitudinal data from Taiwan National Health Insurance Research Database. The study cohort comprised 5344 patients with diagnosis of ESRD on hemodialysis or peritoneal dialysis during the period from January 1996 to December 2011. For each ESRD patient, we selected 20 non-ESRD patients matched on age and sex. Each ESRD patient and his/her controls were followed from the initiation of renal dialysis until either the diagnosis of RVO or censorship. Kaplan-Meier method was used to compare the hazard of RVO between cohorts. Stratified Cox proportional hazard models were applied to estimate the hazard ratio (HR) adjusted by the comorbidities of RVO including diabetes mellitus (DM), hypertension, hypercholesteremia, and hypertriglyceridemia. After stratifying by DM status, the statistics were applied again to examine the associations among the DM cohort and non-DM cohort.The 16-year RVO cumulative incidence for ESRD cohort was 2-fold to the non-ESRD (1.01% vs 0.46%). After matching with age, sex, hypertension, and hypercholesteremia, the adjusted HR was 1.46 (95% confidence interval = 1.07-2.01, P value = 0.018). By further excluding patients with DM, the adjusted HR escalated to 2.43 (95% confidence interval = 1.54-3.83, P < 0.001). In contrast, there was no significant risk of ESRD on RVO in the DM patients (HR = 1.03). We conclude that among the non-DM patients, ESRD cases had significantly higher RVO rate than the non-ESRD, which indicates that ESRD maybe a potential risk factor for the development of RVO in nondiabetic patients.

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

Background

To evaluate the role of plasma total homocysteine (tHcy) and homozygosity for the thermolabile variant of the methylenetetrahydrofolate reductase (MTHFR) C677T genotype in the risk of retinal vein occlusion (RVO).

Methods

Relevant studies were selected through an extensive search of PubMed, EMBASE, and the Web of Science databases. Summary weighted mean differences (WMDs) or odds ratios (ORs) and 95% confidence intervals (CI) were calculated with a random-effects model.

Results

Forty-two studies with 6445 participants were included in this updated systematic review and meta-analysis. The mean plasma tHcy level in the RVO patients was significantly higher than in the controls (WMD =2.13 μmol/L; 95% CI: 1.29 to 2.98, P < 0.001), but there was evidence of between-study heterogeneity (P < 0.001). No significant association between MTHFR C677T genotype and RVO was found under all genetic models.

Conclusion

There was some evidence that plasma tHcy is associated with an increased risk of RVO. There was no evidence to suggest an association between homozygosity for the MTHFR C677T genotype and RVO.

Intense exercise causing central retinal vein occlusion in a young patient: case report and review of the literature

We report a 19-year-old patient who developed a central retinal vein occlusion (CRVO) with significant macular edema and visual impairment following intense exercise and dehydration. The patient was treated with 3 intravitreal bevacizumab injections with complete resolution. A review of the literature on the cause and treatment for CRVO in young patients was performed, focusing on the role of intense exercise and dehydration as a rare pathogenesis mechanism of CRVO.

Hyperhomocysteinia is a risk factor for retinal venous occlusion: a case control study

BACKGROUND

We evaluated the role of hyperhomocysteinemia as a risk factor for retinal vein occlusion (RVO) in Indian patients.

TYPE OF STUDY

Matched case control type of longitudinal study was conducted in 2006-2007.

MATERIALS AND METHODS

Two medical retina specialists examined the eyes having an event of RVO in the last 15 days. A similar number of eyes without RVO were also examined. The serum and urine homocysteine levels of these persons were tested. Matched pair analysis was carried out to determine the risk of RVO among those with hyperhomocysteinemia.

RESULTS

We included 20 cases of RVO and 20 age- and sex-matched persons without RVO. The risk of RVO was significantly higher in persons with hyperhomocysteinemia [difference of mean 31.62 μmol/L (95% Confidence Interval 16.60-47 . 86), P = 2.1 × 10-13 ]. The mean urine homocysteine level among cases and controls was not statistically significant. There were 12 persons with hypertension in both cases and control groups.

CONCLUSION

Hyperhomocysteinemia is a risk factor for RVO. Any list of investigations for a case of RVO should include total plasma homocysteine (tHcy) levels.

[Evaluation of coagulopathies and fibrinolytic abnormalities in central retinal vein occlusion in patients under 60 years of age]

PURPOSE

To investigate the association of thrombophilic and fibrinolytic factors with central retinal vein occlusion (CRVO) in patients under 60 years of age.

MATERIALS AND METHODS

A prospective, observational study of 21 patients with CRVO compared with an age- and sex-matched control group of 23 volunteers was performed. All participants were tested for: cholesterol, hypertension, factors VIII, IX, and XI, homocysteine, antiphospholipid antibodies, antithrombin III, proteins C and S, protein Z and protein Z antibodies, resistance to activated protein C, factor V Leiden mutation, prothrombin mutation, MTHFR genotypes, plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (t-PA) polymorphisms.

RESULTS

There was a significantly higher rate of hyperhomocysteinemia (23.8% versus 0%, P=0.018) in CRVO patients. Increased level of factor VIII was more common in the CRVO group at diagnosis (23.8% versus 0%, P=0.018) but no significant difference was observed after one month (P=0.1). Hypercholesterolemia was more common in the CRVO group (42.8% versus 17.4%, P=0.09). Thirty-eight percent of patients with CRVO were hypertensive. Frequencies of other hypercoagulable states were rare. No significant differences were observed for hereditary fibrinolytic abnormalities.

DISCUSSION AND CONCLUSION

Among the coagulopathies studied, hyperhomocysteinemia appears to be a risk factor for central retinal vein occlusion in patients under 60 years of age. Conversely, polymorphisms of fibrinolytic factors do not appear to play a role in this population.

Central retinal vein occlusion in a young Chinese population: risk factors and associated morbidity and mortality

PURPOSE

The purpose of this study was to assess the risk factors for central retinal vein occlusion and associated morbidity and mortality in a Chinese population.

METHODS

The participants included patients with central retinal vein occlusion 40 years old and younger. Predisposing factors, mortality, and systemic complications were examined in this group.

RESULTS

Unilateral (n = 19) and bilateral (n = 3) central retinal vein occlusions were identified in a total of 22 patients (25 eyes), with a mean follow-up time of 37 months. Hypercholesterolemia (65%), hypertriglyceridemia (64%), and hyperhomocysteinemia (42%) were all identified as risk factors. Three patients (14%) developed stroke and 1 (5%) developed transient ischemic attacks during follow-up. Renal failure and pulmonary hypertension resulted in the death of two patients. The mean initial and final visual acuities (+ or - standard deviation) were 20/400 (+ or - 20/250) and 20/500 (+ or - 20/320), respectively, and treatments did not result in vision improvement (P = 0.57). The poor visual prognosis was likely due to macular edema in 7 eyes (28%), optic atrophy in 4 eyes (16%), and secondary glaucoma in 3 eyes (12%).

CONCLUSION

Morbidity and mortality are high in young Chinese patients with central retinal vein occlusion who may have associated serious complications including stroke, blindness, and death. Central retinal vein occlusion may serve as an initial clinical presentation of serious systemic diseases.

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.

Comparative analysis of homocysteine concentrations in patients with retinal vein occlusion versus thrombotic and atherosclerotic disorders

The objectives of the present study were to determine the concentrations of plasma homocysteine in a large (n = 562) cohort of patients with retinal vein occlusion (RVO) and to compare them with the values observed in other vascular thrombotic and atherosclerotic conditions. Results were compared with those observed in patients with deep vein thrombosis (n = 1700), pulmonary embolism (n = 542), transient ischemic attack (n = 1301), cerebrovascular accident (n = 1299), myocardial infarction (n = 3087), as well as peripheral artery occlusive disease (n = 1946). No differences were found between the age-adjusted estimated marginal mean +/- SE for homocysteine concentrations in individuals with RVO and in those who had other atherosclerotic and atherothrombotic diseases The respective concentrations for RVO, deep vein thrombosis, pulmonary embolism, transient ischemic attack, cerebrovascular accident, myocardial infarction, and peripheral artery occlusive disease were 13.8 +/- 0.4, 14.7 +/- 0.3, 14.3 +/- 0.5, 14.2 +/- 0.3,14.6 +/- 0.3, 13.8 +/- 0.2, 14.4 +/- 0.2 pmol/l for men and 11.4 +/- 0.4, 10.7 +/- 0.2, 10.8 +/- 0.3, 10.8 +/- 0.2, 11.8 +/- 0.2, 11.2 +/- 0.2 pmol/l for women. In conclusion, the concentrations of homocysteine observed in patients with RVO are similar to those detected in other thrombotic and atherosclerotic vascular disorders. In view of the fact that this is a common disorder of the elderly, increased homocysteine concentrations often reported in patients with RVO could reflect the underlying atherothrombotic condition and might not necessarily be specifically related to the RVO per se. This information is relevant in researching the potential etiopathologic role, if any, of increased homocysteine concentrations in RVO.

Serum PON1 arylesterase activity in relation to hyperhomocysteinaemia and oxidative stress in young adult central retinal venous occlusion patients

AIM

To estimate the arylesterase activity of serum paraoxonase-1 (PON1-ARE), which is reported to have an antioxidant and antiatherogenic potential and to correlate with plasma homocysteine (Hcys) and plasma TBARS in young adult central retinal venous occlusion (CRVO) patients.

METHODS

A case-control prospective study carried out in 10 CRVO patients (mean age 27+/-5 years; 7 males, 3 females) and 20 healthy controls (mean age 29+/-5 years; 15 males, 5 females).

RESULTS

The CRVO patients showed a significantly lowered serum PON1-ARE activity (P=0.009) along with a significant increase in the levels of plasma Hcys (P=0.018) when compared to the control subjects. There was a negative correlation between serum PON1-ARE and plasma Hcys levels (P=0.058) as well as between PON1-ARE and plasma TBARS levels (P=0.001) in the CRVO patients.

CONCLUSION

This is the first report of lowered serum PON1-ARE level as a risk factor for CRVO (OR= 1.108, CI=0.914, 1.314; P=0.296), which is found to correlate with oxidative stress.

Central retinal venous occlusion in an otherwise-healthy child

Isolated retinal venous occlusion rarely occurs in otherwise-healthy children.(1-3) We report a unilateral case of central retinal vein occlusion with secondary proliferative retinopathy and neovascular glaucoma in a 6-year-old girl. Despite an extensive workup, no etiology was identified.

Homocysteine, MTHFR C677T gene polymorphism, folic acid and vitamin B 12 in patients with retinal vein occlusion

Background

Many available data have suggested that hyperhomocysteinaemia, an established independent risk factor for thrombosis (arterial and venous), may be associated with an increased risk of retinal vein occlusion (RVO).

Aim of the study

To evaluate homocysteine metabolism in consecutive caucasian patients affected by RVO from Northern Italy.

Patients and Methods

69 consecutive patients from Northern Italy (mean age 64.1 ± 14.6 yy) with recent RVO, were tested for plasma levels of homocysteine (tHcy: fasting and after loading with methionine), cyanocobalamine and folic acid levels (CMIA-Abbot) and looking for MTHFR C677T mutation (Light Cycler-Roche) and compared to 50 volunteers, enrolled as a control group.

Results

Fasting levels of tHcy were significantly higher in patients than in controls: mean value 14.7 ± 7.7 vs 10.2 ± 8 nmol/ml. Post load levels were also significantly higher: mean value 42.7 ± 23.7 vs 30.4 ± 13.3 nmol/ml; Total homocysteine increase was also evaluated (i.e. Δ-tHcy) after methionine load and was also significantly higher in patients compared to control subjects: mean Δ-tHcy 27.8 ± 21.5 vs 21.0 ± 16 nmol/ml (normal value < 25 nmol/ml). Furthermore, patients affected by RVO show low folic acid and/or vitamin B12 levels, although differences with control group did not reach statistical significance. Heterozygous and homozygous MTHFR mutation were respectively in study group 46% and 29% vs control group 56% and 4%.

Conclusion

our data confirm that hyperhomocysteinaemia is a risk factor for RVO, and also that TT genotype of MTHFR C677T is more frequently associated with RVO: if the mutation per se is a risk factor for RVO remains an open question to be confirmed because another study from US did not reveal this aspect.

Hyperomocysteinemia is modifiable risk factor for thrombotic diseases. Therefore, a screening for tHcy plasma levels in patients with recent retinal vein occlusion could allow to identify patients who might benefit from supplementation with vitamins and normalization of homocysteine levels, in fasting and after methionine load.