In some developing countries, vitamin A deficiency in the diet and associated keratomalacia are a major cause of childhood blindness. In such regions, vitamin A deficiency frequently arises as part of nonselective general malnutrition in child’s and young children.
Keratomalacia is a medical condition and eye disorder, in which cornea becomes dry and clouding over because of dietary calories, protein, and vitamin A deficiencies. Vitamin A is essential for normal vision as well as proper bone growth, healthy skin, and protection of the mucous membranes of the digestive, respiratory, and urinary tracts against infection. The cornea’s surface dies, and bacterial infections and corneal ulcers can follow. The conjunctiva and tear glands may also be affected, causing dry eyes and tear production. Early symptoms may include poor vision at night or in dim light and extreme dryness of the eyes.
With advancing vitamin A deficiency, dry, "foamy," silver-gray deposits may appear on the delicate membranes covering the whites of the eyes. Without adequate treatment, increasing softening of the corneas may lead to corneal infection, rupture and degenerative tissue changes, resulting in blindness. Protein-energy malnutrition is related with keratomalacia - the diet is likely to be deficient in Vitamin A due to reduced intake but starvation also affects the metabolism of Vitamin A.
Although rare in developed countries, vitamin A deficiency and keratomalacia may occur secondary to conditions related with impaired absorption, storage, or transport of vitamin A, such as celiac disease, ulcerative colitis, cystic fibrosis, liver disease, or intestinal bypass surgery and any condition that affects absorption of fat-soluble vitamins. Keratomalacia presents with bilateral central grey, sluggish corneal ulcers surrounded by dull, hazy cornea, sometimes with photophobia.
Night blindness (poor vision in the dark) may grow because of vitamin A deficiency. Keratomalacia is characterized by a misty, dry cornea that becomes denuded. Corneal ulceration with secondary infection is common. The lacrimal glands and conjunctiva are also affected. Antibiotic eye drops or ointments can assist cure an infection, but correcting the vitamin a deficiency and malnutrition with an improved diet or supplements are also important. High dose oral Vitamin A supplementation for children with measles in developing countries and high measles immunisation coverage.
