Plasma Homocysteine Concentrations in the Acute Phase After Central Retinal Vein Occlusion in a Chinese Population

OCULAR DECOMPRESSION RETINOPATHY WITH BRANCH RETINAL VEIN OCCLUSION MTHF-R GENETIC MUTATION

PURPOSE

An atypical case of a sectorial decompression retinopathy with branch retinal vein occlusion following trabeculectomy was reported and was diagnosed with optical coherence tomography angiography for which systemic genetic assessment revealed a MTHF-R mutation.

METHOD

Single case report.

RESULTS

A 68-year-old woman diagnosed with an uncontrolled bilateral creeping angle glaucoma went through an uncomplicated trabeculectomy in both eyes. Best-corrected visual acuity was 20/20. Intraocular pressure changed from 28 mmHg preoperatively to 5 mmHG postoperatively in the right eye. On the first postoperative day, best-corrected visual acuity was 20/32 with intraocular pressure measured to 5 mmHg. Fundus examination revealed sectorial temporal hemorrhages with tortuous temporal superior retinal vein arcade and choroidal folds. Fluorescein angiography evidenced a slight delay in venous filling along the supratemporal arcade. Three months later, optical coherence tomography angiography showed macular capillary loops in the superotemporal area of the retina. This sectorial decompression retinopathy was evocative of a branch retinal vein occlusion. At 6 months, best-corrected visual acuity returned to 20/20, with full regression of the hemorrhages. Systemic workup was normal, but genetic assessment revealed a MTHF-R mutation.

CONCLUSION

Retinal vein occlusion can be considered as a feature of ocular decompression retinopathy. The present case is the first case to associate branch retinal vein occlusion secondary to ocular decompression retinopathy to a MTHF-R mutation.

Central retinal vein occlusion after laparoscopic sleeve gastrectomy in an 18-year-Old female

Purpose

To describe a case of central retinal vein occlusion (CRVO) in a young adult found to have elevated homocysteine after bariatric surgery and to review risk factors for CRVO in younger patients.

Observations

An 18-year-old female presented with a CRVO and severe cystoid macular edema (CME). She was normotensive, not on medications, and without known heritable hypercoagulable disease. Her medical history was notable for bariatric surgery and subsequently she was found to have nutritional deficiency, anemia, and elevated homocysteine. Her elevated homocysteine may have induced a hypercoaguable state that predisposed her to developing a CRVO. Treatment with bevacizumab dramatically improved her macular edema and visual acuity. Nutritional supplementation was initiated.

Conclusions

Elevated homocysteine in the setting of nutritional deficiency from prior bariatric surgery may cause a hypercoaguable state and is a potential risk factor for CRVO.

Importance

With the increasing prevalence of obesity and bariatric surgery, it is important to consider associated nutrient deficiency as a potential cause of induced hypercoagulability and increased risk for CRVO. Identification of these at-risk patients is especially important given this condition is easily treatable and may be present in younger individuals. To the best of our knowledge, this is the first reported case of a CRVO with elevated homocysteine in the setting of nutrient deficiencies from laparoscopic sleeve gastrectomy.

Vitamin B12 and Folate as Risk Factors for Retinal Vein Occlusion: A Meta-Analysis

PURPOSE

To evaluate the association between serum vitamin B12/folate and retinal vein occlusion (RVO).

METHODS

A comprehensive search of the PubMed database was performed, which identified 271 abstracts to be screened. Ten studies met our inclusion criteria and a meta-analysis of these comparative case-control studies was performed on the mean ± standard deviation serum vitamin B12 and folate levels, without language restrictions. Nine studies with 720 patients with RVO and 613 controls were included in the meta-analysis for vitamin B12, and 10 studies with 784 patients with RVO and 677 controls in the meta-analysis for folate.

RESULTS

There was no statistically significant difference between patients with RVO and controls in serum vitamin B12 levels (mean difference: - 40.25 pg/mL, p = 0.28), either central RVO (mean difference: - 18.24 pg/mL, p = 0.71) or branch RVO (mean difference: - 23.56 pg/mL, p = 0.48). On the contrary, the plasma folate level was significantly lower in RVO patients than in controls (mean difference: - 1.34 ng/mL, p = 0.001), as well as in patients with CRVO compared to controls (mean difference: - 1.48 ng/mL, p = 0.006), but not in BRVO patients (mean difference: - 0.72 ng/mL, p = 0.11).

CONCLUSIONS

RVO is associated with low serum folate levels, but not with serum vitamin B12 levels.

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.

Meta-analysis of the relationship between methylenetetrahydrofolate reductase C677T and A1298C polymorphism and venous thromboembolism in the Caucasian and Asian

Recent years, it is a highly debated topic that whether methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and A1298C polymorphism could increase susceptibility to venous thromboembolism (VTE) in the Asian and Caucasian. Therefore, we expect to settle that controversy evidentially. Basic methods: Electronic databases (Pubmed, embase, Cochrane library, scopus, OvidSP, Wiley Online library, Springer link, EBSCO, Elsevier Science Direct, Google scholar) without date limitation were searched. Crude odds ratio (OR) along with 95% confidence interval (95% CI) was calculated to assess the association quantitatively. Finally, a total of 37 eligible studies were included, containing 31 for MTHFR C677T polymorphism and 6 for MTHFR A1298C polymorphism. The pooled results suggested that MTHFR C677T mutation may increase susceptibility to VTE in reverse recessive model (CC+CT vs TT): OR = 0.68 (0.56, 0.83), reverse dominant model (CC vs CT +TT): OR = 0.82 (0.72, 0.94), heterozygote model (CT vs TT): OR = 0.65 (0.52, 0.81), homozygote model (CC vs TT): OR = 0.73 (0.60, 0.89) and allele model (C vs T): OR = 0.80 (0.71, 0.90). Subgroup analysis about Asian also support that results, but Caucasian group not. In addition, MTHFR A1298C polymorphism may be not related to VTE in all genetic model. The results of meta-analysis indicated that MTHFR C677T polymorphism might increase the risk of VTE, especially in Asian population.

Circular RNAs: Novel Promising Biomarkers in Ocular Diseases

Circular RNAs (circRNAs) are a novel class of endogenous non-coding RNAs produced by back-splicing. They are found to be expressed in eukaryotic cells and play certain roles in various cellular functions, including fibrosis, cell proliferation, differentiation, apoptosis and angiogenesis. Dysregulated circRNAs are found in several human disorders including, malignancy, vascular, inflammatory as well as nervous diseases. Although, increasing evidence suggests that circRNAs may also contribute in different ocular diseases, the outline of circRNAs in ocular diseases remains obscure. In this review we consider the current state of knowledge regarding the potential role and underlying mechanism of circRNAs in ocular diseases including pterygium, age-related cataract, glaucoma, diabetic retinopathy, retinoblastoma, retinal vascular dysfunction and hyperhomocysteinemia induced ocular diseases, emphasizing that circRNAs could be promising biomarkers for the diagnosis and prognosis evaluation. Future circRNAs-targeted intervention may become a novel therapeutic tool for the treatment of ocular diseases.

Plasma homocysteine levels are associated with macular thickness in type 2 diabetes without diabetic macular edema

PURPOSE

To explore the relationships between macular thickness and the plasma concentrations of homocysteine, vitamin B12, folate, and other known risk factors for patients with diabetes without diabetic macular edema (DME).

METHODS

Fasting venous blood samples were collected from 252 subjects (126 relatively healthy subjects with type 2 diabetes without diabetic macular edema and 126 age- and gender-matched controls). Measurement of macular thickness and volume was performed for those subjects using SD-OCT. The plasma concentrations of homocysteine, vitamin B12, folate, and other known risk factors were analyzed in all the patients and controls using multiple linear regression models.

RESULTS

An increase in the serum levels of homocysteine was present within patients with type 2 diabetes compared to healthy individuals. The mean total plasma homocysteine levels were associated with a greater central subfield macular thickness (CSMT), average macular thickness (AMT), and average macular volume (AMV) in patients with type 2 diabetes without DME, after adjusting for age, sex, duration of diabetes, and HbA1c. Each 1 mmol/L increase in tHcy level was associated with a 6.57 µm greater CSMT (95% confidence interval [CI] 1.78, 11.36), a 4.51 µm greater AMT (95% CI 1.05, 7.98), and a 4.72 mm³ greater AMV (95% CI 1.23, 8.21).

CONCLUSIONS

Higher homocysteine levels were associated with an increased CSMT, AMT, and AMV in diabetic patients without DME. This link may indicate that patients with type 2 diabetes with increased levels of plasma tHcy are more prone to develop a clinical manifestation of DME.

Antiphospholipid antibody and risk of retinal vein occlusion: a systematic review and meta-analysis

BACKGROUND

Retinal vein occlusion (RVO) is a common retinal vascular disease and it is one of the most frequently reported causes of visual damage and blindness in the elderly. The current study investigated the potential association between antiphospholipid antibodies (APLA) and RVO risk by conducting a meta-analysis of case-control studies.

METHODS

A systematic literature search of Pubmed and Embase databases was conducted in August 1st, 2014. Odds ratios (ORs) were used to evaluate the associations between APLA and the incidence of RVO. A random-effects model was obtained for the quantitative synthesis.

RESULTS

A total of 11 studies were included in this meta-analysis. A meta-analysis of all studies assessing the risk of RVO revealed that APLA was associated with a statistically increased risk of RVO incidence (OR = 5.18, 95% CI = [3.37, 7.95]). The association between anticardiolipin antibodies (ACA) and the risk of RVO was significant (n =8, OR = 4.59, 95% CI = [2.75, 7.66]). However, the association between lupus anticoagulants (LA) and risk of RVO was non-significant (n = 5, OR = 3.90, 95% CI = [0.99, 15.37]). No significant publication bias was found in the 11 selected studies.

CONCLUSION

APLA was significantly associated with the risk of RVO. Advanced analyses showed that ACA rather than LA affected the risk of RVO. Additional well-designed and well-conducted epidemiological studies are required to further our understanding of the relationship between APLA and RVO risk.

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.

Association between MTHFR C677T polymorphism and venous thromboembolism risk in the Chinese population: a meta-analysis of 24 case-controlled studies

The association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and venous thromboembolism (VTE) risk in the Chinese population has been widely reported, but results were inconsistent and underpowered. To elucidate the variable results, a meta-analysis and systematic review were performed from all case-controlled studies relating MTHFR C677T polymorphism by pooling data on them. We estimated the pooled odds ratio with its 95% confidence intervals to assess this possible association. Finally, a total of 24 studies with 2339 cases and 4048 controls were included in the current meta-analysis. Significant association was found with VTE risk for all genetic models. Subgroup analyses by type of VTE further identified the above-mentioned association in deep vein thrombosis/pulmonary embolism and splanchnic vein thrombosis. The findings from our meta-analysis support the associations of MTHFR C677T polymorphism with VTE risk in the Chinese population.