vitamin-b-12 and Retinal-Degeneration

Inherited disorders of cobalamin (cbl) metabolism (cblA-J) result in accumulation of methylmalonic acid (MMA) and/or homocystinuria (HCU). Clinical presentation includes ophthalmological manifestations related to retina, optic nerve and posterior visual alterations, mainly reported in cblC and sporadically in other cbl inborn errors.We searched MEDLINE EMBASE and Cochrane Library, and analyzed articles reporting ocular manifestations in cbl inborn errors. Out of 166 studies a total of 52 studies reporting 163 cbl and 24 mut cases were included. Ocular manifestations were found in all cbl defects except for cblB and cblD-MMA; cblC was the most frequent disorder affecting 137 (84.0%) patients. The c.271dupA was the most common pathogenic variant, accounting for 70/105 (66.7%) cases. One hundred and thirty-seven out of 154 (88.9%) patients presented with early-onset disease (0-12 months). Nystagmus and strabismus were observed in all groups with the exception of MMA patients while maculopathy and peripheral retinal degeneration were almost exclusively found in MMA-HCU patients. Optic nerve damage ranging from mild temporal disc pallor to complete atrophy was prevalent in MMA-HCU.and MMA groups. Nystagmus was frequent in early-onset patients. Retinal and macular degeneration worsened despite early treatment and stabilized systemic function in these patients. The functional prognosis remains poor with final visual acuity < 20/200 in 55.6% (25/45) of cases. In conclusion, the spectrum of eye disease in Cbl patients depends on metabolic severity and age of onset. The development of visual manifestations over time despite early metabolic treatment point out the need for specific innovative therapies.

Topics: Amino Acid Metabolism, Inborn Errors; Homocystinuria; Humans; Macular Degeneration; Methylmalonic Acid; Mutation; Retina; Retinal Degeneration; Vitamin B 12

To compare peripapillary retinal nerve fiber layer (RNFL) thicknesses measured by Cirrus HD optical coherence tomography (OCT) of patients with vitamin B12 deficiency with healthy controls and to evaluate the correlation between the peripapillary RNFL thickness and plasma vitamin B12 levels.. Forty-five patients (19 male and 26 female) with a diagnosis of vitamin B12 deficiency (patient group) and 45 age- and sex- matched healthy subjects (control group) were consecutively enrolled in this study. Average, temporal, nasal, inferior, and superior quadrant peripapillary RNFL thicknesses of each subject were obtained using the Cirrus HD OCT. Disc area (DA) and rim area (RA), central subfield thickness (CST), cube volume (CV), and cube average thickness (CAT) were also measured.. Mean age of each group was 33.1 ± 6.5 years (range: 21-45 years). Mean plasma vitamin B12 level was 114.8 ± 34.0 pg/mL in the patient group and was 405.1 ± 20.0 pg/mL in the control group (p < 0.001). The patient and control groups were similar regarding axial length, plasma folate levels, DA, RA, CST, CV, CAT, and RNFL thicknesses in superior, nasal, and inferior quadrants. However, average RNFL and RNFL in temporal quadrant were significantly thinner in the patient group than in the control group (p = 0.013 and p < 0.001, respectively). In addition, temporal (r = 0.356, p = 0.001) and average (r = 0.212, p = 0.045) peripapillary RNFL thicknesses were correlated with plasma vitamin B12 levels.. We have shown that, as in other non-glaucomatous optic neuropathies, temporal quadrant RNFL thickness was thinner in patients with vitamin B12 deficiency and it was correlated with plasma vitamin B12 levels. Further studies are warranted to clarify the clinical relevance of these findings and the effects of vitamin B12 replacement therapy.

Topics: Adult; Female; Glaucoma; Humans; Male; Middle Aged; Nerve Fibers; Optic Disk; Optic Nerve Diseases; Retina; Retinal Degeneration; Tomography, Optical Coherence; Vitamin B 12; Vitamin B 12 Deficiency; Young Adult

Combined methylmalonic aciduria with homocystinuria (cblC type) is a rare disease caused by mutations in the MMACHC gene. MMACHC encodes an enzyme crucial for intracellular vitamin B

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amino Acid Metabolism, Inborn Errors; Animals; Female; Homocysteine; Homocystinuria; Humans; Male; Methylmalonic Acid; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Transgenic; Middle Aged; Mutation; Oxidoreductases; Phenotype; Retina; Retinal Degeneration; Vitamin B 12; Young Adult

To describe the association between retinal degeneration and cobalamin C (cblC) disease and to review previously published ophthalmic data regarding cblC disease.. Descriptive case series of three patients and compilation of all previously reported cases of cblC disease in the ophthalmic literature.. All three new cases presented with macular pigmentary changes and showed attenuation of electroretinographic responses. Sequential ERG (electroretinogram) testing in Case 1 demonstrated ERGs that began at the lower limits of normal and became progressively attenuated over time.. Cobalamin C disease results in progressive retinal degeneration with its onset in the first few months of life and progressing rapidly over the first few years of life.

Topics: Electroretinography; Female; Humans; Infant, Newborn; Retina; Retinal Degeneration; Vitamin B 12; Vitamin B 12 Deficiency

Topics: Adolescent; Female; Fluorescein Angiography; Fundus Oculi; Homocystinuria; Humans; Retinal Degeneration; Transcobalamins; Vitamin B 12

A 33-month-old boy with an inborn error of vitamin B12 metabolism characterized by methylmalonic aciduria, homocystinuria, cystathioninuria , and hypomethioninemia had poor vision and a progressive retinal pigmentary degeneration. The child had early growth retardation with microcephaly, developmental delay, and a megaloblastic anemia. The retinal lesions were first noted when he was 1 year of age and, by ophthalmoscopy and by electroretinographic testing, have progressed. Treatment with hydroxocobalamin and L-methionine improved the anemia and the biochemical abnormalities but apparently did not halt the retinal degeneration. We believe the retinopathy is a feature of this disease, particularly in patients with infantile involvement. The retinal lesion may be caused by an unidentified abnormality of sulfur amino acid metabolism.

Topics: Amino Acid Metabolism, Inborn Errors; Amino Acids, Sulfur; Child, Preschool; Cystathionine; Growth Disorders; Homocystinuria; Humans; Hydroxocobalamin; Male; Malonates; Methionine; Methylmalonic Acid; Retinal Degeneration; Vitamin B 12

A 63-years-old male with pernicious anemia had been treated for 20 years with weekly injections of iron-dextran and cyanocobalamine. Ophthalmological examination revealed the ophthalmoscopic picture of a tapetoretinal degeneration, reduced visual acuity and narrow visual fields. ERG and dark-adaptation test were normal. Hematological examination including liver and bone marrow biopsies gave no support for the existence of systemic siderosis. It is proposed that the retinal degeneration is due to the extensive parenteral iron treatment with a total dose of approximately 100 grams of iron. This theory is supported by a previous experimental report.

Topics: Aged; Anemia, Pernicious; Drug Therapy, Combination; Fluorescein Angiography; Humans; Injections, Intramuscular; Iron-Dextran Complex; Male; Retinal Degeneration; Retinitis Pigmentosa; Vitamin B 12

Topics: Cobamides; Corrinoids; Hematinics; Rare Diseases; Retinal Degeneration; Vitamin B 12

Topics: Adenine Nucleotides; Adenosine; Corrinoids; Hematinics; Humans; Retinal Degeneration; Retinal Detachment; Thiamine; Vitamin B 12