After 17 years of living off of Pringles, sliced ham, white bread, sausages, and fries, an anonymous teenager in England developed a condition far more at home in disaster zones that in an English town.
According to a case report published this week in the Annals of Internal Medicine, years of severely picky eating (it’s more like an eating disorder) slowly took a toll on this teenager’s eyesight until he was legally blind, highlighting an often overlooked side effect of poor nutrition:
…the patient confessed that, since elementary school, he would not eat certain textures of food. He had a daily portion of fries from the local fish and chip shop and snacked on Pringles (Kellogg), white bread, processed ham slices, and sausage.
When he was 15, he began noticing hearing loss, which was followed by vision loss two years later. His vision was 20/200, which is enough to qualify as legally blind in the US, and fulfills one of the requirements to be certified as “severely sight impaired” in the UK.
"This is not a new problem.”
Atan tells Inverse that vision loss connected to a poor diet is not a new problem.
The condition is called nutritional optic neuropathy, and it’s more common in war zones or during times of famine, according to the US National Center for Biotechnology, than in places where it’s possible to eat fries every day for lunch.
The teenager’s rare condition makes the case even more puzzling, but it drives home the connection between diet and vision, Atan says.
“We hear a lot about how our diet influences cardiovascular health, cancer, dementia, mortality, but not vision,” says Atan. “Eye specialists are well aware of the link between vision and nutrition but awareness among other health professionals is not as good and hopefully this case report will mean fewer cases are missed or the diagnosis delayed.”
How Can Diet Cause Blindness?
Nutritional optic neuropathy occurs because of damage to the optic nerve (the nerve that transmits visual signals from the eye to the brain) due to lack of key vitamins. If that damage remains untreated, it leads to permanent blindness over months or years.
Typically, the condition occurs when people are lacking in B vitamins like thiamine (B1), niacin (B3), pyridoxine (B6), and folate (B9), as well as minerals like calcium, magnesium, and copper. But Atan explains that the deficiency must be severe to cause vision problems, which is why the condition is commonly found during famines or in war zones.
“Globally, lack of food supply in low-income countries wracked by war or poverty would cause poor vision,” she explains.
That just makes this case even more unusual, says Atan. This patient wasn’t “visibly malnourished” and was eating enough to have a normal height and weight. Early on, when he first sought treatment for hearing loss, doctors were aware that he was severely vitamin B deficient, and gave him vitamin B12 injections, along with “dietary advice.”
But eventually those treatments stopped, and his poor diet persisted. Over time, his vision fell victim to a condition that is more often seen in people who are in disastrous circumstances
Blindness and Diet in Wealthy Countries:
This case report doesn’t have the same power as a well designed experiment, but it does highlight an important point about poor diets. They are “energy rich”, meaning they’re high in calories, but at the same time, a truly poor diet is lacking key nutrients. This causes unintended effects, even if you’re not starving.
“Nutritional deficiencies are common. However, blindness is an uncommon complication,” she adds.
As far as nutritional optic neuropathy goes, diet alone isn’t usually the cause in rich countries, says Atan.
People who get the condition in wealthy countries often acquire it as a result of other conditions that limit their vitamin absorption, or because of medications that disrupt this process. But it’s often seen in alcoholics, who are getting most of their calories from alcohol. Potential vision loss aside, alcohol dependency is dangerous enough on it’s own.
Still, this case illustrates how severe cases of disordered eating can usher in vision loss — though if it’s caught early it can be prevented. Atan says that if doctors had managed to get at the real root of this patient’s deteriorating vision earlier, they may have been able to prevent it.
“Purely dietary causes are uncommon but not unheard of. This case was unusual because it was caught late when the potential for recovery with treatment is limited,” she adds.
But just because this condition is rare, that doesn’t mean that somewhere out there, there isn’t another severely picky eater running a similar risk. And Atan hopes that by publishing this letter, the team might be able to catch the condition in time to save someone else’s eyesight.