From the Guidelines
Vitamin A deficiency is a significant cause of painless vision loss, and treatment involves oral supplementation with 10,000-25,000 IU daily for 1-2 weeks, as recommended by the British Obesity and Metabolic Surgery Society guidelines 1. The most critical vitamin deficiencies associated with painless vision loss are:
- Vitamin A deficiency, which can lead to night blindness and xerophthalmia, eventually causing permanent blindness if untreated
- Vitamin B12 deficiency, which can cause optic neuropathy
- Vitamin B1 (thiamine) deficiency, which can lead to nutritional optic neuropathy and Wernicke's encephalopathy with visual disturbances
- Vitamin B9 (folate) deficiency, which may also contribute to optic neuropathy
Treatment Options
For vitamin A deficiency, the recommended treatment is 10,000-25,000 IU oral vitamin A daily for 1-2 weeks, with a recheck of vitamin A levels at 3 months 1. In cases where vitamin A deficiency does not respond to treatment, referral to a specialist for assessment and consideration of intramuscular vitamin A injections is recommended 1. It is essential to address underlying causes such as malnutrition, alcoholism, or malabsorption disorders, and a balanced diet rich in these vitamins can help prevent these deficiencies in the first place. Early diagnosis and prompt treatment are crucial, as some vision changes may become irreversible if the deficiencies persist for too long. According to the British Obesity and Metabolic Surgery Society guidelines, for adults, treatment of vitamin A deficiency involves 10,000-25,000 IU oral vitamin A daily for 1-2 weeks for clinical improvement, and rechecking vitamin A levels at 3 months 1. In adolescents with vitamin A deficiency, referral for specialist support is recommended 1. Additionally, vitamin A deficiency can lead to impaired vision, night blindness, corneal dryness, and dry hair, particularly in bariatric patients after a BPD procedure due to limited absorption area, fat malabsorption, and bacterial overgrowth 1.
From the Research
Vitamin Deficiencies Associated with Painless Vision Loss
- Vitamin B12 deficiency: This deficiency can cause severe irreversible visual loss secondary to optic neuropathy 2. It is a rare but important manifestation of vitamin B12 deficiency and should be suspected in patients with risk factors for malnutrition 3.
- Folic acid and vitamin B complex deficiency: These deficiencies are commonly associated with nutritional optic neuropathy, which is characterized by painless, gradually progressing, bilateral and symmetrical decrease in visual acuity 4.
- Vitamin A deficiency: This deficiency can cause night blindness and keratomalacia, and is often linked to nutritional causes 5.
Treatment of Vitamin Deficiencies Associated with Painless Vision Loss
- Dietary supplementation: Treatment of nutritional optic neuropathy includes dietary supplementation aimed at compensating for the deficient nutrients, such as folic acid, vitamin B complex, and protein replacement 4.
- Vitamin B12 supplementation: Parenteral vitamin B12 supplementation can improve vision in patients with vitamin B12 deficiency-related optic neuropathy 3.
- Elimination of risk factors: Eliminating risk factors of neuropathy, such as chronic alcohol abuse and poor dietary habits, is also an important part of treatment 4.
Key Considerations
- Early treatment commencement: Early treatment commencement, prior to irreversible optic nerve atrophy, is a prerequisite of effective treatment 4.
- Differential diagnosis: The differential diagnosis with other causes of optic nerve involvement, in particular of toxic origin, may be particularly difficult 6.