Visual failure caused by vitamin B12 deficiency optic neuropathy

Effects of B12 Deficiency Anemia on Radial Peripapillary and Macular Vessel Density: An Optical Coherence Tomography Angiography (OCTA) Study

BACKGROUND

To evaluate the macular and optic disc vascular changes in vitamin B12 deficiency anemia.

METHODS

A total of 24 patients with vitamin B12 deficiency anemia and 24 healthy controls were involved in this study. All participants were evaluated for central macular thickness (CMT), peripapillary retina nerve fiber layer (RNFL) thickness, foveal avascular zone (FAZ) area, macular vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP), choriocapillaris flow area, and optic disc radial peripapillary capillary (RPC) VD using optic coherence tomography (OCT) and optic coherence tomography angiography (OCTA). Metabolic parameters were also noted.

RESULTS

Temporal RNFL thickness significantly decreased in the B12 deficiency anemia group (p = 0.04). Choriocapillaris flow area (p = 0.045) and macular vessel density in both SCP (p = 0.022) and DCP (p = 0.018) markedly declined in the study group. Optic disc RPC VD in the B12 deficiency anemia group was lower in all regions compared to that of the control group, but the difference was not statistically significant (p > 0.05). There were significant positive correlations between choriocapillaris flow area, macular VD, vitamin B12, and hemoglobin.

CONCLUSION

Retinal vascular alterations were observed in B12 deficiency anemia, and OCTA may be beneficial in the diagnosis and follow-up of ocular complications in these cases.

Evaluation of macular, retinal nerve fiber layer and choroidal thickness by optical coherence tomography in children and adolescents with vitamin B12 deficiency

PURPOSE

To investigate macular, Retinal Nerve Fiber Layer (RNFL) and choroidal thickness in children and adolescents with vitamin B₁₂ deficiency and no neurological examination finding.

METHODS

The study group includes of thirty-three children aged 8-17 years who were brought to the Pediatric outpatient clinic with the symptoms of fatigue and forgetfulness and whose Vitamin B₁₂ levels were detected < 200 pg/ml. The control group was the 30 children and adolescents applied to the same policlinic with various symptoms and whose Vitamin B₁₂ levels were found normal. Children and adolescents with chronic systemic/ocular disease history and myopia or hyperopia more than 4 diopters were not included in both groups. Spectral Domain-Optical Coherence Tomography (SD-OCT) was used for measurements.

RESULTS

Mean Macular thickness value was 261.2 ± 17.6 in the Vitamin B₁₂ deficiency group and 267.7 ± 17.4 in the control group. Mean value of Retinal Nerve Fiber Layer (RNFL) thickness was 103.5 ± 7.5 in the Vitamin B₁₂ deficiency group and 104.3 ± 8.9 in the control group. The mean values of Choroidal thickness were 360.1 ± 59.8 and 316.9 ± 95.4 in Vitamin B₁₂ deficiency and control groups, respectively. There was a statistically significant increase in choroidal thickness in Vitamin B₁₂ deficiency group compared to controls.

CONCLUSION

Statistically significant increase in the Choroidal thicknesses of children and adolescents with Vitamin B₁₂ deficiency is important in terms of shedding light on studies that will contribute to a better understanding of the relationship between vitamin B₁₂ and inflammation.

CLINICAL TRIAL REGISTRATION

This study is an observational study.

Optic neuropathy as a presenting feature of vitamin B-12 deficiency: A systematic review of literature and a case report

Introduction

Vitamin B12 (VitB12) deficiency rarely manifests with visual symptoms. Optic nerve damage in VitB12 deficiency is thought to be via degeneration. However, optic neuritis, though infrequent, has been reported secondary to VitB12 deficiency.

Material and methods

We conducted a systematic review of all the reported cases of VitB12 deficiency with optic nerve involvement in Pubmed, Cochrane, and Google Scholar any date up to September 6, 2020. We have discussed the findings and compiled the available information on ophthalmological manifestations of VitB12 deficiency. We aim to provide a unified knowledge about the evidence related to types of optic neuropathies reported to date secondary to VitB12 deficiency. We also present a case of bilateral optic neuritis secondary to VitB12 deficiency.

Presentation of case

We present a 29-year-old previously healthy male with progressive, painful, bilateral, but asymmetric visual deterioration for forty-five days. A detailed history, examination, and laboratory workup were carried out. He was diagnosed as having optic neuritis secondary to VitB12 deficiency. He showed partial improvement with the replacement of VitB12.

Conclusion

We suggest promptly identifying and replacing VitB12 in patients with optic neuritis with proven VitB12 deficiency to prevent permanent damage to the optic nerve. Patients with VitB12 deficiency should have a baseline fundoscopic exam to rule out subclinical optic nerve damage. Moreover, patients who present with visual disturbances should be screened for VitB12 deficiency, especially the vegan population.

•

B 12 deficiency can present with optic neuropathy as an initial manifestation.

•

B 12 deficiency-induced optic neuropathy may be reversible if identified timely.

•

In patients with visual disturbance, B12 levels should be checked with a fundus exam.

•

A subclinical optic neuropathy should be ruled out in B12 deficient patients.

Ethambutol and isoniazid induced severe neurotoxicity in a patient undergoing continuous ambulatory peritoneal dialysis

Ethambutol (EMB) and isoniazid (INH) are the first-line antituberculosis (anti-TB) drugs. However, their neurotoxicity could cause adverse effect and the patients with end-stage renal disease are especially vulnerable due to the reduction in renal drug clearance. Here, we report a 36-year-old man receiving peritoneal dialysis developed progressive paralysis in lower extremities, vision loss and hoarseness 4 months after anti-TB treatment with INH, EMB and rifapentine because of concomitant pulmonary tuberculosis. A diagnosis of EMB/INH-induced peripheral neuropathy, retrobulbar neuritis and laryngoparalysis was made. The patient's neuropathy gradually improved 2 years after discontinuation of EMB/INH. Since EMB and INH may cause simultaneously severe and complex multineuropathy in dialysis patients, their adverse effects should be closely supervised in dialysis patients.

Cobalamin-Associated Superoxide Scavenging in Neuronal Cells Is a Potential Mechanism for Vitamin B12-Deprivation Optic Neuropathy

Chronic deficiency of vitamin B₁₂ is the only nutritional deficiency definitively proved to cause optic neuropathy and loss of vision. The mechanism by which this occurs is unknown. Optic neuropathies are associated with death of retinal ganglion cells (RGCs), neurons that project their axons along the optic nerve to the brain. Injury to RGC axons causes a burst of intracellular superoxide, which then signals RGC apoptosis. Vitamin B₁₂ (cobalamin) was recently shown to be a superoxide scavenger, with a rate constant similar to superoxide dismutase. Given that vitamin B₁₂ deficiency causes an optic neuropathy through unknown mechanisms and that it is a potent superoxide scavenger, we tested whether cobalamin, a vitamin B₁₂ vitamer, would be neuroprotective in vitro and in vivo. We found that cobalamin scavenged superoxide in neuronal cells in vitro treated with the reduction-oxidation cycling agent menadione. In vivo confocal scanning laser ophthalmoscopy demonstrated that optic nerve transection in Long-Evans rats increased superoxide levels in RGCs. The RGC superoxide burst was significantly reduced by intravitreal cobalamin and resulted in increased RGC survival. These data demonstrate that cobalamin may function as an endogenous neuroprotectant for RGCs through a superoxide-associated mechanism.

Pseudo-Foster Kennedy Syndrome as a Rare Presentation of Vitamin B12 Deficiency

Introduction

Pseudo-Foster Kennedy syndrome is a triad consisting of ipsilateral optic atrophy, contralateral optic disc edema, and ipsilateral anosmia in the absence of an intracranial mass. Vitamin B12 plays an important role in DNA synthesis, and its deficiency causes peripheral neuropathy, myeloneuropathy, and, very rarely, optic neuropathy.

Case Presentation

In this study, we describe a 34-year-old male who presented with progressive loss of visual acuity and field. Fundoscopy showed optic disc edema with telangiectasia in the right eye, while the left eye had optic disc atrophy. We ruled out nearly all possible and common causes of optic neuropathy, and vitamin B12 deficiency was finally diagnosed. After treatment with vitamin B12, the patient improved.

Conclusions

Demyelinating disease, anterior ischemic optic neuropathy, non-arteritic anterior ischemic optic neuropathy, autoimmune disease, and hereditary optic neuropathy could cause optic neuropathy. Normal CBC parameters and the absence of clinical manifestations of vitamin B12 deficiency could not rule out its diagnosis. Careful physical examinations and history-taking with a classical approach led us to the diagnosis of vitamin B12 deficiency and its treatment.

Assessment of peripapillary retinal nerve fiber layer thickness in children with vitamin B12 deficiency

PURPOSE

Vitamin B(12) deficiency is a worldwide problem. It affects all ages, including children. It is one of the most common nutritional disorders and can cause harmful effects on the nervous system. In this study, we compared the peripapillary retinal nerve fiber layer thickness (RNFLT) in a healthy control group with children with vitamin B(12) deficiency. In our study, we aimed to evaluate the effect of vitamin B(12) deficiency on the RNFLT in children with the optical coherence tomography (OCT) method.

METHODS

Sixty-six children with a diagnosis of vitamin B(12) deficiency (patient group) and 66 age- and sex-matched healthy children (control group) were enrolled in this prospectively designed study. Blood counts, vitamin B(12) levels, folate levels, and full biochemical parameters were obtained for all the subjects in each group. Peripapillary RNFLT measurements were performed with Cirrus HD spectral domain OCT.

RESULTS

The thickness of the superior retinal nerve fiber layer (RNFL) in the vitamin B(12) deficiency group was significantly lower than that of the control group (p = 0.037). Although the average thickness of the RNFL was lower in the patient group, there was no statistically significant differences (p = 0.216). In the vitamin B(12) deficiency group, the average RNFL thickness and the superior RNFL thickness were significantly correlated with vitamin B(12) levels ((r1) = 0.353, (p1) < 0.004 and (r2) = 0.416, (p2) = 0.001, respectively).

CONCLUSION

Our study showed that a deficiency in vitamin B(12), elsewhere it is important for the development of the central nervous system, is associated with a reduction in the thickness of the superior RNFL.

Optic neuropathy among a prison population in Papua New Guinea

PURPOSE

To estimate the prevalence of optic neuropathy (ON) among prisoners in a provincial prison in Papua New Guinea, and to explore risk factors for this condition among this population.

METHODS

Cross-sectional observation study of 148 male prisoners aged ≥18 years using an interview-based questionnaire, assessment of visual and nervous system function, ocular examination, and blood analysis (α-tocopherol, β-carotene, lutein, folate, homocysteine, holotranscobalamin II, riboflavin, selenium, thiamin, and vitamins A, B(12) and C). Likelihood of the presence of ON was based on ordered groups determined by weighted combination of optic nerve head appearance and visual dysfunction (acuity, field, color perception). Main outcome measures were prevalence and associations of ON.

RESULTS

Sample prevalence of clinical ON was 10.4% (95% confidence interval [CI], 6.2-16.8). No cases were found of unexplained non-visual nervous system dysfunction, including peripheral neuropathy. Increasing age (p = 0.001), length of current (p = 0.002) and lifetime (p = 0.03) incarceration, and duration of smoking by current smokers (p = 0.001) were associated with increased ON likelihood. However, when age-controlled, the smoking duration association was not maintained (p = 0.6). Prisoners were folate deficient. Adjusting for age and duration of current incarceration, whole blood (p = 0.02) and red blood cell (p = 0.04) folate concentrations were inversely associated with ON likelihood. No association was found for any other assessed demographic, lifestyle or biochemical measure.

CONCLUSIONS

A cluster of ON associated with folate deficiency has been identified. Recommendations for dietary change and micronutrient supplementation have been made.

Assessment of peripapillary retinal nerve fiber layer thickness in children with vitamin B12 deficiency

PURPOSE

Vitamin B(12) deficiency is a worldwide problem. It affects all ages, including children. It is one of the most common nutritional disorders and can cause harmful effects on the nervous system. In this study, we compared the peripapillary retinal nerve fiber layer thickness (RNFLT) in a healthy control group with children with vitamin B(12) deficiency. In our study, we aimed to evaluate the effect of vitamin B(12) deficiency on the RNFLT in children with the optical coherence tomography (OCT) method.

METHODS

Sixty-six children with a diagnosis of vitamin B(12) deficiency (patient group) and 66 age- and sex-matched healthy children (control group) were enrolled in this prospectively designed study. Blood counts, vitamin B(12) levels, folate levels, and full biochemical parameters were obtained for all the subjects in each group. Peripapillary RNFLT measurements were performed with Cirrus HD spectral domain OCT.

RESULTS

The thickness of the superior retinal nerve fiber layer (RNFL) in the vitamin B(12) deficiency group was significantly lower than that of the control group (p = 0.037). Although the average thickness of the RNFL was lower in the patient group, there was no statistically significant differences (p = 0.216). In the vitamin B(12) deficiency group, the average RNFL thickness and the superior RNFL thickness were significantly correlated with vitamin B(12) levels ((r1) = 0.353, (p1) < 0.004 and (r2) = 0.416, (p2) = 0.001, respectively).

CONCLUSION

Our study showed that a deficiency in vitamin B(12), elsewhere it is important for the development of the central nervous system, is associated with a reduction in the thickness of the superior RNFL.

Vitamin B12 deficiency optic neuropathy detected by asymptomatic screening

Asymptomatic bilateral optic disc swelling was detected in a 19-year-old man with type 1 diabetes through routine photographic screening for retinopathy. He was found to have significant vitamin B(12) deficiency which the authors believe was the cause for the optic neuropathy. After B(12) replacement, visual function and optic disc appearances returned to normal.

[Neurological manifestations of vitamin B12 deficiency: a retrospective study of 26 cases]

PURPOSE

Neurological symptoms of B12 vitamin deficiency are polymorph. Causes are dominated by Biermer's disease and B12 vitamin non dissociation that is frequent in the elderly.

METHODS

We realized a retrospective study during 11 years. Patients with neurological symptoms associated to megaloblastosis were included. Treatment with B12 vitamin lead to haematological manifestation regression.

RESULTS

26 cases were analyzed. Mean age was 50+/-14.5 years and there were 11 women and 15 men. Neurological signs included combined medullar sclerosis (N = 10), peripheral neuropathy (N = 10), isolated paresthesia (N = 5) and inferior limb pyramidal syndrome (N = 1). Neurological signs revealed vitamin B12 deficiency in 4 cases. Mean haemoglobin rate was 6.2+/-2.6 g/dl, mean MCV was 109+/-56 fl. Eight patients had macrocytic anaemia, nine bi-cytopenia and eight deep pancytopenia. Electromyography (N = 8) confirmed neuropathy and medullar MRI (N = 2) showed antero-posterior cordonal demyelinisation of cervico-dorsal medulla. Causes of B12 vitamin deficiency were Biermer's disease (N = 11), non dissociation of B12 vitamin's syndrome (N = 8) and partial gastrectomy (N = 1). In 6 patients, no aetiology was found. Treatment with parenteral vitamin B12 induced neurological symptoms regression in 14 cases. Patient with neurological disorder had significantly higher platelet count and haemoglobin level as compared with patients without neurological disorder. Reticulocyte crisis was more precocious in patients with neurological disorders.

CONCLUSION

Neurological symptoms in vitamin B12 deficiency are frequent. We insist on isolated forms, inaugural forms and on the interest of medullar MRI for early diagnosis.