Xerophthalmia is a progressive ocular disease caused by vitamin A deficiency.
A lack of this vitamin can dry out the tear ducts and eyes. Xerophthalmia can turn into night blindness or more severe damage to the cornea, the outer layer of your eye.
This damage can take the form of white spots on the eyes and ulcers on the corneas. In general, xerophthalmia can be reversed with vitamin A therapy.
Symptoms of xerophthalmia begin mildly and then progressively worsen if a vitamin A deficiency is not treated. If you have this condition, the thin lining of your eyelid and eyeball, called the conjunctiva, dries, thickens, and begins to wrinkle.
Night blindness is an early symptom. This is an inability to see in low light. The World Health Organization and public health workers have used several cases of night blindness as an indicator of vitamin A deficiency in a population.
As xerophthalmia progresses, lesions form on the cornea. You can also get corneal ulcers. In the later stages of the disease, part or all of your cornea deteriorates. This eventually leads to blindness.
A lack of vitamin A causes xerophthalmia. Your body does not produce vitamin A by itself. Instead, it would help if you get vitamin A from your foods.
Vitamin A is essential for vision because it is a protein element that absorbs light in the retina receptors.
This vitamin is also essential for the function and maintenance of your heart, lungs, kidneys, and other organs.
This disease is seen most in developing countries where people may have limited access to products of animal origin.
Sources of vitamin A
Vitamin A is also known as retinol. It is a fat-soluble substance found in products of animal origin, such as:
- Liver of fish
- Dairy products
It is also possible to obtain vitamin A from plant sources in the form of beta carotenes. Beta carotenes are converted to retinol in the intestine. But this process is inefficient as a source of vitamin A compared to consuming products of animal origin.
Sources of beta carotenes include:
- Green leafy vegetables
- Fruits, yellow and orange vegetables
- Red palm oil
How common is this condition?
Vitamin A deficiency and xerophthalmia are significant public health problems in the developing world and affect millions of women and children. It is the leading cause of blindness in children.
A 2002 study found that around 4.4 million preschoolers worldwide had xerophthalmia. More than 6 million women develop night blindness during pregnancy annually.
Who is at risk for xerophthalmia?
The most significant risk of xerophthalmia is poverty and the lack of an adequate diet, especially the lack of products of animal origin. Babies and children are at greater risk. The younger the child is, the more severe are the effects of vitamin A deficiency.
Children require a lot of vitamin A to grow. Vitamin A deficiency also affects the ability to survive common childhood infections and diseases, such as diarrhea, measles, and respiratory infections.
The following are risk factors because they affect a person’s ability to absorb vitamin A:
- Cystic fibrosis
- Diseases such as celiac disease that limit the absorption of nutrients
- Liver diseases, such as cirrhosis
- Chronic diarrhea
- Treatment with radioactive iodine for thyroid cancer can produce non-permanent symptoms of xerophthalmia.
What should you expect when you see your doctor?
Your doctor will do a physical exam and ask you about your symptoms and diet.
If you have night blindness, your doctor can start with vitamin A therapy, even before blood tests.
Sometimes, corneal xerophthalmia ulcers are confused with bacterial infections. As a result, your doctor may prescribe an antibiotic. More tests may be needed to detect vitamin A deficiency.
Xerophthalmia was described in antiquity by the Greeks and the Egyptians. The Egyptians treated it with animal liver, the organ that stores vitamin A.
Vitamin A supplementation is the immediate treatment for xerophthalmia. This vitamin can be taken orally or injected. The dose varies according to your age and general health status.
In more advanced cases where the cornea is damaged, you can receive antibiotics to prevent secondary infections. You may need to keep your eye covered to protect it until the injury heals.
Vitamin A supplements can quickly reverse the symptoms of xerophthalmia and help protect children from death from other childhood diseases.
Vitamin A supplements are given preventatively in areas where xerophthalmia is a known problem.
This is a low-cost way to prevent human suffering and deaths. A 2007 study estimated that 500 million capsules of vitamin A are distributed annually at a relatively low cost of 10 cents per capsule.
Nutrition education can be critical in helping people make the best use of their food resources. Strengthening commercial foods with vitamin A also helps reduce the deficiency of this vitamin.
Some foods that can be fortified include:
- Oils and fats
Another possible source of vitamin A is golden rice, which is genetically engineered to contain beta-carotene.
Xerophthalmia improves rapidly with vitamin A supplements. In very advanced cases, scarring can remain and affect vision. In the worst case, permanent blindness can occur.
Vitamin A deficiency and xerophthalmia remain major public health problems in the developing world and areas of war or natural disasters.
The availability and affordability of a proper diet, including animal products and leafy greens, is critical.