Poor diet can lead to blindness

September 02, 2019

An extreme case of "fussy" or "picky" eating caused a young patient's blindness, according to a new case report published today [2 Sep 2019] in Annals of Internal Medicine.

The University of Bristol researchers who examined the case recommend clinicians consider nutritional optic neuropathy in any patients with unexplained vision symptoms and poor diet, regardless of BMI, to avoid permanent vision loss.

Nutritional optic neuropathy is a dysfunction of the optic nerve which is important for vision. The condition is reversible, if caught early. But, left untreated, it can lead to permanent structural damage to the optic nerve and blindness.

In developed countries like the UK, the most common causes of nutritional optic neuropathy are bowel problems or drugs that interfere with the absorption of various important nutrients from the stomach. Purely dietary causes are less common because food supply is good, but elsewhere in the world, poverty, war and drought are linked to malnutrition and higher rates of nutritional optic neuropathy.

Clinician scientists from Bristol Medical School and the Bristol Eye Hospital examined the case of a teenage patient who first visited his GP complaining of tiredness. The link between his nutritional status and vision was not picked up until much later, and by then, his visual impairment had become permanent.

Aside from being a "fussy eater," the patient had a normal BMI and height and no visible signs of malnutrition and took no medications. Initial tests showed macrocytic anaemia and low vitamin B12 levels, which were treated with vitamin B12 injections and dietary advice. When the patient visited the GP a year later, hearing loss and vision symptoms had developed, but no cause was found. By age 17, the patient's vision had progressively worsened, to the point of blindness. Further investigation found the patient had vitamin B12 deficiency, low copper and selenium levels, a high zinc level, and markedly reduced vitamin D level and bone mineral density. Since starting secondary school, the patient had consumed a limited diet of chips, crisps, white bread, and some processed pork. By the time the patient's condition was diagnosed, the patient had permanently impaired vision.

The researchers concluded that the patient's 'junk food' diet and limited intake of nutritional vitamins and minerals resulted in the onset of nutritional optic neuropathy. They suggest the condition could become more prevalent in future, given the widespread consumption of 'junk food' at the expense of more nutritious options, and the rising popularity of veganism if the vegan diet is not supplemented appropriately to prevent vitamin B12 deficiency.

Dr Denize Atan, the study's lead author and Consultant Senior Lecturer in Ophthalmology at Bristol Medical School and Clinical Lead for Neuro-ophthalmology at Bristol Eye Hospital, said: "Our vision has such an impact on quality of life, education, employment, social interactions, and mental health. This case highlights the impact of diet on visual and physical health, and the fact that calorie intake and BMI are not reliable indicators of nutritional status."

The team recommend dietary history should be part of any routine clinical examination like asking about smoking and alcohol intake. This may avoid a diagnosis of nutritional optic neuropathy being missed or delayed as some associated visual loss can fully recover if the nutritional deficiencies are treated early enough.
-end-
Paper:

'Case report on blindness due to a junk food diet' by D Atan et al in Annals of Internal Medicine.

Further information:

About nutritional optic neuropathy


Our eyes are responsible for detecting different patterns and wavelengths (colours) of light and this information is sent to our brain via the optic nerve. Each time you visit an optometrist and they "look inside/behind your eyes", they are examining the optic nerves to check their health. Optic neuropathy is the medical term for damage to the optic nerve. If the damage is caused by poor nutrition it is referred to as "nutritional optic neuropathy".

Nutritional optic neuropathy is an uncommon but serious complication of a number of different types of nutritional deficiency. And nutritional deficiencies are extremely common. It is estimated that nutritional deficiencies affect approximately 2-billion people worldwide. In low- and middle-income countries, poverty and inadequate food intake are the main causes of micronutrient deficiencies, but micronutrient deficiencies also exist in high-income countries like the UK.

Deficiencies of vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B6 (pyridoxine), vitamin B9 (folate), vitamin B12 (cobalamin), iron, calcium, magnesium, and copper are all known to cause optic neuropathy, and are easily misdiagnosed as other disorders without an adequate dietary history from the patient.

University of Bristol

Related Blindness Articles from Brightsurf:

New eye drops may prevent a common cause of blindness
New eye drops could prevent vision loss after retinal vein occlusion, a major cause of blindness for millions of adults, a study by Columbia University researchers has found.

Scientists pinpoint brain coordinates for face blindness
Danish and Norwegian researchers have moved one step closer to understanding where face blindness stems from in the brain.

Protein closely linked to commonest cause of blindness
An international team of scientists has identified a protein which is strongly linked to the commonest cause of blindness in developed countries when its levels are raised in the blood.

New glaucoma test to help prevent blindness
Researchers have identified 107 genes that increase a person's risk of developing the eye disease glaucoma, and now developed a genetic test to detect those at risk of going blind from it.

Treatments for leading cause of blindness generate $0.9 to $3 billion
A new economic study, published in JAMA Ophthalmology and conducted by USC researchers at the Schaeffer Center for Health Policy & Economics, the Ginsburg Institute for Biomedical Therapeutics, and the Roski Eye Institute, quantifies the benefits of treatment for wAMD.

Identifying a gene for canine night blindness
An international team of researchers led by the University of Pennsylvania's Keiko Miyadera has identified the gene mutation responsible for a form of night blindness in dogs.

Poor diet can lead to blindness
An extreme case of 'fussy' or 'picky' eating caused a young patient's blindness, according to a new case report published today [2 Sep 2019] in Annals of Internal Medicine.

Brighter possibilities for treating blindness
Advances in preclinical research are now being translated into innovative clinical solutions for blindness, a review published in the 10th anniversary series of science Translational Medicine depicts.

How blindness shapes sound processing
Adults who lost their vision at an early age have more refined auditory cortex responses to simple sounds than sighted individuals, according to new neuroimaging research published in JNeurosci.

Study identifies new genes associated with the leading cause of blindness
A new study, published in Clinical Epigenetics, identifies genes associated with Age-related Macular Degeneration (AMD) that could represent new targets for future drug development.

Read More: Blindness News and Blindness Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.