Dados do Trabalho

Título

DIETARY BLIND SPOTS: THE IMPACT OF NUTRITIONAL DEFICIENCIES ON PEDIATRIC OPTIC NERVE HEALTH

Apresentação do caso único

Case Report: A 12-year-old female presented with a four-month history of painless visual impairment, initially affecting her right eye, and progressing to significant bilateral vision loss. The initial diagnosis was amblyopia, but worsening symptoms led to a second opinion, where optic disc changes were noted, prompting referral to a pediatric emergency department. Neurological assessment revealed visual acuity of light perception in the right eye and counting fingers at 1 meter in the left eye. A detailed history indicated that she had been on a highly restrictive diet for at least five years, without nutritional guidance or supplementation. Neuro-ophthalmological evaluation revealed bilateral optic disc pallor. Serum levels of vitamin B12 and vitamin A were undetectable, and homocysteine was elevated at 41.7µmol/L (ref. range: 5-15µmol/L). Brain CT showed skull hyperostosis without optic nerve compression. Advanced neuroimaging did not reveal signs of optic neuritis, and tests for MOG and AQP4 antibodies were negative. Other causes of B12 malabsorption were ruled out and CSF results were normal. The patient was treated with a 5-day course of intravenous methylprednisolone and vitamin supplementation, but no improvement was observed. After 3 months of follow-up, the patient’s visual acuity remained unchanged.

Discussão

Discussion: Optic neuropathy due to B12 deficiency is a rare neurological manifestation, accounting for less than 1% of cases. Although deficiencies in B-complex vitamins and retinol can lead to visual impairment, the underlying mechanisms differ significantly. B12 deficiency disrupts myelin sheath synthesis and regeneration, resulting in optic nerve fiber degeneration and damage to retinal ganglion cell axons. Conversely, vitamin A deficiency leads to optic nerve compression due to hyperostosis of the optic canal. The growing recognition of nutritional deficiencies emphasizes their importance as a differential diagnosis in optic neuropathies.

Comentários finais

Final Comments: This case highlights the neurological risks of restrictive diets, particularly in pediatric populations. It emphasizes the necessity of including nutritional optic neuropathies in the differential diagnosis when risk factors are present. While supplementation is essential, outcomes may be suboptimal if treatment is delayed. Early identification and intervention are crucial to prevent irreversible damage, making comprehensive nutritional assessment a key component in managing visual impairment.

Referências

1. Briani, C.; Dalla Torre, C.; Citton, V.; Manara, R.; Pompanin, S.; Binotto, G.; Adami, F. Cobalamin Deficiency: Clinical Picture and Radiological Findings. Nutrients 2013, 5, 4521-4539. https://doi.org/10.3390/nu5114521;
2. Cheah, J. A. S. S., Muhammed, J., Tharmathurai, S., Hamzah, N., & Rahmat, J. (2022). Optic neuropathy in an autistic child with vitamin A deficiency: A case report and literature review. Cureus, 14(2), e22074. https://doi.org/10.7759/cureus.22074;
3. Roda, M.; di Geronimo, N.; Pellegrini, M.; Schiavi, C. Nutritional Optic Neuropathies: State of the Art and Emerging Evidences. Nutrients 2020, 12, 2653. https://doi.org/10.3390/nu12092653.

Palavras Chave

NUTRITIONAL OPTIC NEUROPATHY; MALNUTRITION AND VISION LOSS; VISION LOSS IN PEDIATRICS