Abstract
Purpose :
Vitamin B12 is a water-soluble essential micronutrient required for the development, myelination, and function of the nervous system. Absorption of vitamin B12 occurs via the GI tract and is impaired with age and certain medication. Deficiency in serum vitamin B12 is more common over age 60 and is known to impact optic nerve function and testing.
Serum B12 levels are considered normal above 250 pg/mL. 3% of men and 8% of women were found to have suboptimal B12 intake in the 2013-2016 National Health and Nutrition Examination Survey. Vitamin B12 deficiency is known to directly impact optic nerve function.
Our working hypothesis was that lower levels of B12 would be more likely to demonstrate abnormalities in optic nerve function, resulting in misdiagnosis of glaucoma or other conditions.
Methods :
We retrospectively examined the impact of low, suboptimal, and normal B12 levels on optic nerve function using perimetry, visual evoked potential, and pattern electroretinography within a population of patients at increased risk for glaucoma.
Results :
We found no correlation between the level of B12 (above 300mg) and electrophysiologic parameters. Due to small numbers, it was not possible to draw conclusions regarding the correlation between various parameters. Of the patients with sub-optimal B12, a majority had concurrent diagnoses of glaucoma or other optic nerve diseases.
Conclusions :
Our data is limited and demonstrates that vitamin B12 deficiency may impact optic nerve function in a way that resembles more common diagnoses such as glaucoma. Our numbers were insufficient to define any correlation between latency, amplitude, phase, or other electrophysiologic parameters. We propose a further study to include larger numbers of patients with a randomization strategy to identify electrophysiologic parameters that may be specifically affected by various ranges of B12 deficiency.
Patients with characteristics of optic nerve disease including glaucomas should be evaluated for B12 deficiency. Not only could the deficiency result in worsening optic nerve function, but it may also influence the ability of the tissue to regenerate and heal. Neurogenesis, like other cytoproliferative events, requires B12. Suboptimal levels of B12 can both impair the diagnosis and also the treatment of glaucoma.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.