Selective thrombophilia screening of patients with nonarteritic anterior ischemic optic neuropathy

Compound Heterozygosity for the C6777T Mutation of the MTHFR Gene and the FII G20210A Mutation of the Prothrombin Gene in Sequential Bilateral Anterior Ischemic Optic Neuropathy

Nonarteritic anterior ischemic optic neuropathy (NA-AION) is the most common form of acute painless, usually unilateral, optic neuropathy in the elderly population. Systemic risk factors include diabetes mellitus, arterial hypertension, sleep apnea syndrome, and cardiovascular disease. Α 52-year-old man developed sequential, bilateral NA-AION, involving a worsening, severe vision compromising attack in the secondly affected eye. Thrombophilia testing revealed compound heterozygosity for the C6777T mutation of the MTHFR gene and the prothrombin G20210A (FII mutation). Oral anticoagulation treatment was initiated. A thorough systemic and family history, especially in the absence of major vasculopathic disease, should alert toward investigation for thrombophilia in middle-aged patients with atypical forms of NA-AION and initiation of anticoagulant treatment should be considered.

Non-Arteritic Anterior Ischemic Optic Neuropathy Following COVID-19 Vaccination

People are advised to receive a vaccine booster as the Delta and Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge, but various adverse ocular reactions after vaccination have been reported. NAION following COVID-19 vaccination appears extremely rarely. Here, we report a case of a 61-year-old female with sudden painless blurred vision developing NAION after receiving ChAdOx1 nCoV-19 (AstraZeneca) vaccination and provide an in-depth explanation of the possible mechanisms regarding the hypercoagulable state after vaccination. Our report adds to the literature on potential adverse ocular effects after COVID-19 vaccination, and we as ophthalmologists recommend that clinicians should increase awareness of this possible ocular complication when evaluating patients with sudden visual disturbance with a recent history of vaccination.

Risk Factors for Non-arteritic Anterior Ischemic Optic Neuropathy: A Large Scale Meta-Analysis

Objective: We conducted a meta-analysis to explore all the potential risk factors for non-arteritic anterior ischemic optic neuropathy (NAION) based on the published literature. Methods: A comprehensive literature search through the online databases was performed to obtain studies concerning the risk factors of NAION up to June 2020. Pooled unadjusted odds ratios (ORs) or rate ratios (RRs) were calculated to evaluate the weight of risk factors. This study was registered in PROSPERO under the number CRD42018084960. Results: Our meta-analysis included 49 original studies comprising of more than 10 million patients. The following risk factors were proved to be significantly associated with NAION: male gender (OR = 1.67, 95% CI: 1.50-1.85, P < 0.00001), hypertension (RR = 1.28, 95% CI: 1.20-1.37, P < 0.00001), hyperlipidemia (RR = 1.43, 95% CI: 1.26-1.62, P < 0.00001), diabetes mellitus (DM) (RR = 1.53, 95% CI: 1.36-1.73, P < 0.00001), coronary heart disease (CHD) (RR = 1.68, 95% CI: 1.24-2.27, P = 0.0008), sleep apnea (RR = 3.28, 95% CI: 2.08-5.17, P < 0.00001), factor V Leiden heterozygous (RR = 2.21, 95% CI: 1.19-4.09, P = 0.01), and medication history of cardiovascular drugs. Conclusion: We concluded that the above risk factors were significantly related to NAION. Better understanding of these risk factors in NAION can help the direct therapeutic approaches.

A Case of Non-Arteritic Anterior Ischemic Optic Neuropathy with COVID-19

Non-arteritic ischemic optic neuropathy (NAION) is thought to be caused by loss of blood flow to the optic nerve which in turn causes an acute, unilateral and painless vision loss that affects older vasculopathic patients. We report a case of a 43-year-old Hispanic male with the classic presentation of NAION in the setting of a coronavirus disease 2019 (COVID-19) infection. It is well documented that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause hypoxemia and thrombophilia in patients, both of which may contribute to the development of NAION. It is uncertain whether the association of NAION and COVID-19 was causal or coincidental but the purpose of this case report is to argue that there is biological plausibility and to help shed light on potential ophthalmologic complications of COVID-19.

Association Study of MTHFR Polymorphisms with Nonarteritic Anterior Ischemic Optic Neuropathy in a Spanish Population

Introduction

Nonarteritic anterior ischemic optic neuropathy (NAION), painless loss of central and/or peripheral vision, is a multifactorial disease caused by insufficient blood flow through the posterior ciliary arteries to the optic nerve head. Mutations in the methylenetetrahydrofolate reductase (MTHFR) gene, triggering hyperhomocysteinemia as a consequence of a decreased activity of the codified enzyme, have been considered to be among the risk factors of NAION.

Objective

The main aim was to study the association of the most common MTHFR genetic polymorphisms C677T and A1298C with NAION in a Spanish population.

Methods

In this case-control study, the association of the most common MTHFR polymorphisms was investigated in 94 unrelated native Spanish patients diagnosed with NAION and 204 healthy controls. Two single nucleotide polymorphisms located in the MTHFR gene, C677T (rs1801133) and A1298C (rs1801131), were analyzed by DNA sequencing and TaqMan assays.

Results

The allelic and genotypic frequencies of the MTHFR variants obtained in the NAION group were not significantly different when compared with the control group. A higher frequency of the C677T/A1298C genotype, codifying the nonmutated MTHFR form, was obtained in control subjects (11.27%) compared to NAION patients (4.26%), suggesting a protective effect of the wild-type protein, although this result was not conclusive considering the obtained confidence interval (CI) (95% CI: 0.13-1.06). Study of additional clinical factors including hypertension, diabetes mellitus, and dyslipidemia showed no association with a higher risk of NAION. Conversely, the clinical history of heart or cerebrovascular diseases was significantly higher in NAION patients compared to controls. Over the world, risk variants of the MTHFR gene are highly frequent, excluding African black populations, indicating a racial influence.

Conclusions

The MTHFR variants did not significantly increase the risk of suffering from NAION. However, considering that individuals with at least one of the risk variants have the MTHFR enzyme with decreased activity, it cannot be ruled out that these mutations are relevant for the development of NAION in a subgroup of the population with other specific characteristics. These may include high plasma levels of homocysteine along with nutritional deficiencies including low folate or vitamin B12 and the combination of systemic and local risk factors.

The polymorphisms of ATOH 7, ET-1 and ACE in non-arteritic anterior ischemic optic neuropathy

Non-arteritic anterior ischemic optic neuropathy (NAION) is a common cause of acute optic neuropathy in the elderly. The role of the genetic polymorphisms of Atonal Homolog 7 (ATOH7), Endothelin-1 (ET-1) and Angiotensin Converting Enzyme (ACE) in NAION and the combined effects of the gene-gene and gene-medical comorbidities on NAION were not clear. We conducted a perspective, case-control study. 71 NAION patients and 142 age and sex-matched healthy controls were enrolled. Single nucleotide polymorphisms of ATOH7 (rs1900004), ET-1 (rs5370) and ACE (rs1799752) were identified by polymerase chain reaction (PCR) method and all PCR products were screened with Sanger sequencing. The prevalence of genetic factors in NAION patients were compared to normal people, and assessed in conditional logistic regression models. The modified effects of gene-gene or gene-medical comorbidities on NAION development were assessed with a multiplicative model. A significant high risk was found in the T allele of ATOH7 in NAION, with an odds ratio (OR) of 1.55 (P = 0.04). Conditional logistic regression analysis, including diabetes and hypertension, revealed that ATOH7 TT genotype carriers conferred a significantly increased risk of NAION (TT/CC + CT, OR = 3.32, 95% confidence interval (CI) = 1.16-9.53, P = 0.03). Interaction analysis showed that ET-1 (P = 0.01), ACE (P = 0.046) and hypertension (P = 0.02) have modified effects on NAION development. Our results showed that the polymorphism of optic disc associated gene-ATOH7 conferred a significant risk of NAION. Combination of ATOH7 and ET-1, ATOH7 and ACE, as well as ATOH7 and hypertension, increased the susceptibility of NAION. Our data may be useful for NAION predicting.

Associations between thrombophilic risk factors and determinants of atherosclerosis and inflammation in patients with non-arteritic anterior ischaemic optic neuropathy

Non-arteritic anterior ischaemic optic neuropathy (NAION) is caused by ischaemia of the optic nerve head. The pathophysiology of NAION is unclear, and no proven effective treatment exists. Patients, methods: We analyzed thrombophilic risk factors and determinants of atherosclerosis and inflammation in 109 consecutive patients and 109 age- and sex-matched volunteers using a case-control design. Results: High levels of fibrinogen (>384 mg/dl; OR 3.2, p = 0.003), factors VIII:C (>183%; OR 2.6, p = 0.02), IX (>153%; OR 2.6, p = 0.026), XI (>142%; OR 3.4, p = 0.006), von Willebrand factor (activity >205%; OR 3.1, p = 0.005; antigen >194%; OR 3.5, p = 0.002), and triglycerides (>228 mg/dl; OR 2.8, p = 0.026), higher platelet counts (>294 000/[uni03BC]l; OR 2.5, p = 0.04), low levels of HDL cholesterol (<40 mg/dl; OR 2.7, p = 0.032), and an accelerated erythrocyte sedimentation rate (>20 mm/h; OR 4.4, p = 0.003) were associated with NAION. Conclusion: Our findings support the contention of a complex pathogenesis of NAION resulting from the coincidence of proatherogenic, prothrombotic and proinflammatory processes. The alterations described could be causative, side effects, or just coincidental findings.

[Analysis of structure, causes, and risk factors of ischemic optic neuro-pathy]

AIM

to analyze the structure, risk factors, and causes of ischemic optic neuropathy (ION).

MATERIAL AND METHODS

A total of 239 patients (303 eyes) with ION and 98 patients (185 eyes) with optic disc drusen were examined. All ION patients underwent general clinical assessment. Those under 50 years of age were also tested for antiphospholipid markers and gene polymorphisms of the coagulation system.

RESULTS

All patients were found to be exposed to two or more modifiable risk factors of ION. A total of 47.1% of cases were judged as being at anatomical risk of anterior ION (AION) with the cup-to-disc ratio in the second eye of less than 0.15 (of less than 0.25 in 53% of cases). Of 98 patients (185 eyes) with optic disc drusen, 5.4% of cases (10 eyes) developed AION. As many as 22% of ION patients were under 50 years of age. Of them, in 32% primary APS was diagnosed, in 3.6% - secondary (in the presence of SLE); all cases were positive for polymorphisms of the coagulation system that determine genetic predisposition to ION (indeed, the frequency of the latter was significantly higher in these patients than in the control group).

CONCLUSION

Ischemic optic neuropathy is an optic nerve disorder that requires thorough medical history taking and comprehensive assessment of the patient in order to identify the causes and risk factors of this disease as well as accompanying pathologies.

Platelet activation by ADP is increased in selected patients with anterior ischemic optic neuropathy or retinal vein occlusion

To investigate whether adenosine diphosphate (ADP)-induced platelet hyperaggregability is associated with nonarteritic anterior ischemic optic neuropathy (NAION) or retinal vein occlusion (RVO). We retrospectively reviewed thrombophilia screening data of patients with NAION or RVO without a history of arterial hypertension, diabetes mellitus, hyperlipidemia, obesity, and cigarette abuse. Patients with a positive family history for thromboembolism were not excluded. Platelet aggregation (area under the curve, AUC) after induction of 0.5, 1.0, and 2.0 µmol of ADP was estimated in 25 NAION and RVO patients and compared with 25 healthy controls. We observed significantly greater platelet aggregation post 0.5 (P = 0.002) and 1.0 (P = 0.008) µmol of ADP among NAION and RVO patients compared with healthy controls. Platelet hyperaggregability was significantly more prevalent in patients than in controls (56% vs. 8%; P = 0.0006). Our results suggest that in NAION and RVO patients without a history of arterial hypertension, diabetes mellitus, hyperlipidemia, obesity, and cigarette abuse, platelets are significantly hyperreactive after induction of very low concentrations of ADP when compared with healthy individuals. This hyperreactivity is particularly evident in patients with a family history of thromboembolism.

Selective Thrombophilia Screening in Young Patients with Retinal Artery Occlusion

Purpose: To investigate the prevalence of various thrombophilic disorders among young patients with retinal artery occlusion (RAO). Procedures: We retrospectively reviewed thrombophilia screening data of young patients ≤60 years of age with RAO and healthy controls matched for gender and age. Results: Thrombophilia screening data of 25 young patients and 62 healthy controls were analyzed. Mean patient age by the time of the RAO was 43.3 ± 10.8 years. Overall, thrombophilic defects were found to be present in 17 patients (68%) compared with 11 of 62 controls (17.7%; p < 0.0001). Multivariate logistic regression analysis confirmed a statistically significant association between the development of RAO and increased levels of lipoprotein(a) (odds ratio: 9.48; p = 0.001) and factor VIII (odds ratio: 6.41; p = 0.024). There was a strong association between the presence of thrombophilic disorders and a personal or family history of thromboembolism (p = 0.01). Conclusions: Our results indicate that screening for thrombophilic disorders among selected young patients with RAO yields positive results in a high percentage of cases.

Nonarteritic anterior ischemic optic neuropathy and double thrombophilic defect: a new observation

We report the first case of nonarteritic anterior ischemic neuropathy (NAION) associated with double thrombophilia: protein S deficiency and prothrombin G20210A mutation. A 58-year-old man is presented including the clinical and laboratory findings, cardiovascular profile and thrombophilia screening. The patient presented with 3/10 vision and an inferior altitudinal defect in the right eye. Funduscopic examination of the right eye revealed a hyperemic optic disk with blurred superior optic disk border and sectoral nerve fiber layer edema. Complete blood count, erythrocyte sedimentation rate and C-reactive protein were normal, suggesting a NAION. A workup of cardiovascular risk factors revealed hyperlipidemia, arterial hypertension and high-risk asymptomatic coronary artery disease. Due to the family history of deep vein thrombosis in the patient's daughter, a thrombophilia screening was additionally performed. The results revealed a double thrombophilic defect, namely congenital protein S deficiency and heterozygosity for prothrombin G20210A mutation, which were also identified in the patient's daughter. Anticoagulant warfarin therapy was initiated and the patient underwent a triple bypass surgery. At three-month follow-up, the right optic disk edema had resolved, leaving a pale superior optic nerve head. Visual acuity in the right eye had slightly improved to 4/10; however, the dense inferior altitudinal field defect had remained unchanged. The patient is currently treated with warfarin, atorvastatin, irbesartan and metoprolol. This case suggests that the first line of investigation in all patients with NAION involves assessment of cardiovascular risk factors. However, careful history taking will identify NAION patients who are eligible for additional thrombophilia screening: young patients without vasculopathic risk factors, bilateral or recurrent NAION, idiopathic or recurrent venous thromboembolism (VTE), positive family history of VTE, and VTE in young age or in unusual sites (e.g. cerebral, hepatic, mesenteric, or renal vein).

Catastrophic antiphospholipid antibody syndrome and cocaine abuse associated with bilateral retinal vascular occlusions

PURPOSE

To describe a case of bilateral central retinal vein occlusion and central retinal artery occlusion associated with antiphospholipid antibody syndrome and cocaine abuse.

METHODS

A single case report of a 44-year-old woman with a history of cocaine abuse, vasculitis, and 3 spontaneous abortions who developed painless complete loss of vision in both eyes concurrently with progressive motor and sensory polyneuropathy. The patient underwent an extensive laboratory, radiographic, ophthalmologic, and pathologic workup.

RESULTS

Diagnosis of catastrophic antiphospholipid antibody syndrome was made based on established clinical and laboratory criteria, including a positive Russell's viper venom test, history of three spontaneous abortions and evidence of microvascular and macrovascular venous occlusions, and multiorgan failure. Urine toxicology screen was positive for cocaine metabolites. Her clinical course was remarkable for progressive mononeuritis multiplex and quadriplegia. She had no light perception on presentation, and fundus examination revealed extensive preretinal, intraretinal, and subretinal hemorrhages. Fluorescein angiography revealed complete occlusion of central retinal arteriolar and venular flow and retinal hemorrhages in both eyes.

CONCLUSION

Bilateral central retinal vein occlusion and central retinal artery occlusion have been rarely reported in the literature and are often associated with underlying thrombotic risk factors, such as antiphospholipid antibody syndrome. Workup for underlying hypercoagulability and/or cocaine use should be considered in atypical and bilateral cases of central vein or artery occlusion. In this case, bilateral central retinal artery and vein occlusions developed as manifestations of catastrophic antiphospholipid antibody syndrome, which has not been previously reported.

Anterior ischemic optic neuropathy in a patient with Crohn's disease and aberrant MTHFR and GPIIIa gene variants

Large spectrums of ophthalmic manifestations from the anterior to the posterior segment have been so far reported in patients with inflammatory bowel disease. Anterior ischemic optic neuropathy is caused by acute ischemic infarction of the optic nerve head and is distinguished in two different types, non-arteritic anterior ischemic optic neuroparhy (NAION) which is the most frequent type and arteritic anterior ischemic optic neuropathy. Non-arteritic anterior ischemic optic neuroparhy may result in severe visual field loss. We present the case of a 69 year-old man with known history of Crohn's disease that was referred to the Department of Ophthalmology after noticing sudden blurred vision of his left eye. Ophthalmologic examination revealed a corrected visual acuity of 8/10 OS and 10/10 OD. Pupil examination showed a relative afferent pupillary defect of the left pupil and fluoroangiography revealed hyperfluorescence of the left optic disc, indicating edema and NAION attack on his left eye. Genetic analysis showed that the patient was homozygous for MTHFR C677T genetic polymorphism and A1/A2 heterozygous for GPIIIa polymorphism.

Thrombophilic risk factors in the pathogenesis of non-arteritic anterior ischemic optic neuropathy patients

BACKGROUND

Non-arteritic anterior ischemic optic neuropathy (N-AION) is caused by acute ischemic infarction of the optic nerve head, supplied by the posterior ciliary arteries. Thrombophilia is the tendency/predisposition to vascular thromboses of arteries and veins, and the existence of thrombophilic risk factors leads to blood hypercoagulability and potentially increased risk for thromboses.

OBJECTIVES

To investigate whether there is an association between N-AION and a wide spectrum of thrombophilic risk factors.

PATIENTS AND METHODS

Seventy-seven consecutive cases of confirmed N-AION and 60 age- and sex-matched consecutive controls constituted the study group. Fibrinogen levels, deficiency of proteins C, S, ATIII, lupus anticoagulant, activated protein C resistance, factor V Leiden, factor V H1299R, factor II G20210A, MTHFR C677T, MTHFR A1298C, GPIIIa A1/A2, and ACE I/D polymorphisms were analysed.

RESULTS

Statistical analysis of the plasma proteins in our study demonstrated that the only significant difference was the one concerning protein S levels. In particular, the mean value for N-AION patients was 78.8% +/- 21.2, and for the control group the mean value was 88% +/- 21.2 (p = 0.013). Despite the above-mentioned result, there was not any statistical difference between the two subgroups regarding actual protein S deficiency, as 9/77 (11.7%) patients and 4/60 (6.7%) controls had protein S levels below 60% (p = 0.32). In our study sample, homozygosity for MTHFR C677T polymorphism in the study group as a whole, and the presence of at least one A2 allele of GPIIIa in the subgroup of male patients as compared to healthy male controls, proved to be the most significant thrombophilic risk factors, with odds ratios of 16.78 (95% C.I 0.96-294.42, p = 0.054) and 4.6 (95% C.I 1.52-13.88, p = 0.007) respectively.

CONCLUSION

Screening for these polymorphisms would probably constitute a valuable procedure in N-AION patients, as they may have an important contribution to the pathogenesis of the disease.