Patient Profile: 14-Year-Old British Boy
Symptoms: The boy was brought to his general practitioner due to excessive fatigue. The doctor noted his eating habits, describing him as a “picky eater.” Remarkably, the boy exhibited no other symptoms besides persistent tiredness. For more details, see this report.
Diagnostic tests revealed mild anemia and low vitamin B12 levels. Vitamin B12 is essential for red blood cell health and the nervous system, and it can only be acquired through diet. The physician recommended dietary changes and initiated vitamin B12 injections.
Subsequent Developments: At age 15, the teenager began experiencing vision difficulties. Despite thorough eye examinations showing no abnormalities, the root cause of the vision impairment remained undetermined, gradually worsening over time. At 17, he was referred to a neuro-ophthalmologist for further evaluation of his declining eyesight. Neuro-ophthalmologists specialize in vision issues linked to the nervous system.
Follow-up tests gauged the boy’s visual acuity, revealing a score of 20/200 in both eyes. This means that an object visible at 200 feet to someone with standard vision (20/20) would only be discernible at 20 feet for him. A score of 20/200 or lower qualifies as legal blindness, according to the American Foundation for the Blind.
The patient denied using any drugs, alcohol, or tobacco, and there were no apparent ailments in his eyes, wounds, or injuries. Neurological examinations yielded normal results.
Blood tests indicated that the boy’s red blood cells were enlarged, suggesting a possible vitamin deficiency. Additionally, blood levels of copper and vitamin D were lower than average, while elevated homocysteine and methylmalonic acid levels hinted at inadequate vitamin B12, echoing previous findings.
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Diagnosis: The patient admitted he had stopped receiving the prescribed vitamin B12 injections (the exact timeline was not specified). Although his Body Mass Index (BMI) was considered normal for his height and weight, his B12 levels were alarmingly low, raising concerns about his dietary habits.
He alleged an aversion to certain food textures, leading him to restrict his diet significantly since elementary school. His daily intake consisted primarily of fast food—french fries, white bread, potato chips, sausage, and cured ham—resulting in severe nutritional deficiencies.
This inadequate diet led to a condition known as nutritional optic neuropathy, a rare form of vision impairment often linked to severe deficiencies of vitamin B12 and other vital vitamins. This condition leads to the atrophy of the optic nerve, responsible for transmitting visual information from the eyes to the brain. According to the report’s authors, copper deficiency can also contribute to optic nerve damage and enlarged red blood cells.
Treatment: The medical team prescribed nutritional supplements aimed at correcting his deficiencies and referred him to mental health services for his food aversions, identified as an eating disorder.
Despite treatment, while his vision did not worsen further, there was no substantial improvement. Nutritional optic neuropathy can be reversible if identified early; however, once optic nerve atrophy occurs, vision loss is often irreversible, per the report’s findings.
Unique Aspects of This Case: Nutritional optic neuropathy rarely arises from dietary deficiencies alone. Historically, documented cases are often tied to malnutrition due to war and starvation. Recent cases typically involve both undernutrition and malnutrition, often exacerbated by substance abuse.
The teenage boy’s case is particularly noteworthy because his normal BMI concealed a vitamin deficiency that ultimately resulted in vision loss. This illustrates that a healthy weight does not guarantee proper nutrition.
Consequently, the authors recommend that “nutritional optic neuropathy should be considered for patients experiencing unexplained visual disturbances or those with inadequate diets, irrespective of BMI.”
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This article is intended for informational purposes only and does not constitute medical advice.
Harrison, R., Warburton, V., Lux, A., and Eitan, D. (2019). Blindness due to a junk food diet. Annual Report of Internal Medicine, 171(11), 859. https://doi.org/10.7326/l19-0361
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Source: www.livescience.com