From the Guidelines
Vitamin B12 deficiency is a critical cause of optic neuritis, and immediate treatment with hydroxocobalamin 1 mg intramuscularly on alternate days is essential to prevent further neurological damage, as recommended by the British Obesity and Metabolic Surgery Society guidelines 1.
Key Points to Consider
- Vitamin B12 deficiency can lead to demyelination of the optic nerve fibers, resulting in inflammation and vision problems.
- Patients with B12 deficiency-related optic neuritis require prompt treatment to prevent permanent vision loss.
- The treatment regimen for vitamin B12 deficiency involves administering hydroxocobalamin 1 mg intramuscularly on alternate days until there is no further improvement, then maintaining with 1 mg intramuscularly every 2 months 1.
- Folate deficiency may also contribute to optic neuritis, but it is crucial to treat vitamin B12 deficiency first to avoid masking the underlying condition 1.
- Other vitamins, such as thiamine, riboflavin, and vitamin A, may play a role in optic neuritis, but vitamin B12 deficiency is the most significant and well-documented cause 1.
Treatment Approach
- For patients with vitamin B12 deficiency and possible neurological involvement, such as unexplained sensory and/or motor and gait symptoms, urgent specialist advice from a neurologist and haematologist should be sought 1.
- Hydroxocobalamin 1 mg intramuscularly should be administered on alternate days until there is no further improvement, then maintained with 1 mg intramuscularly every 2 months 1.
- For patients with vitamin B12 deficiency and no neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered three times a week for 2 weeks, followed by maintenance treatment with 1 mg intramuscularly every 2–3 months for life 1.
From the Research
Vitamin Deficiencies Causing Optic Neuritis
- Vitamin B12 deficiency has been reported to cause optic neuritis, although it is a rare manifestation 2, 3.
- Optic neuropathy is a reversible and treatable cause of vision loss in patients with vitamin B12 deficiency 3.
- Vitamin B12 deficiency can affect individuals of all ages, but the elderly and those with restricted dietary intake of animal-derived foods are at higher risk 4, 5.
- The diagnosis of vitamin B12 deficiency is based on clinical suspicion and laboratory testing, including measurements of circulating total B12 and transcobalamin-bound B12, as well as homocysteine and methylmalonic acid levels 5, 6.
- Treatment of vitamin B12 deficiency involves supplementation, either orally or parenterally, to prevent permanent damage to the optic nerve and other complications 2, 3.
- Patients with vitamin B12 deficiency should undergo a baseline fundoscopic exam to rule out subclinical optic nerve damage, and those presenting with visual disturbances should be screened for vitamin B12 deficiency, especially in high-risk populations such as vegans 2.