Pediatric and Teen CL Care
Vitamin A Deficiency: A Cause for Dry Eye in Children
BY MELANIE FROGOZO, OD, FAAO
Vitamin A deficiency is one of the world’s top five major malnutrition problems. In children under the age of 5 who live in developing countries, it is more common due to limited food availability. However, subclinical vitamin A deficiency is present even in developed countries whose citizens generally do not consider themselves malnourished (Stephens et al, 1996; McAllister et al, 2013; Faustino et al, 2016).
Hypovitaminosis in developed countries may be caused by voluntary restrictive diets, eating disorders, bariatric surgeries mimicking malabsorption syndromes, and chronic diseases that affect organs involved in vitamin A digestion or clearance (McAllister et al, 2013; Faustino et al, 2016). Congenital diseases associated with malabsorption (e.g., cystic fibrosis and short bowel syndrome) can also cause vitamin deficiency (Faustino et al, 2016; Cella et al, 2002). And, due to limited hepatic reserves, children are more susceptible to vitamin A deficiency compared to adults; depletion of vitamin A can happen rapidly in children, especially those struck by illness or infection (McAllister et al, 2013).
Vitamin A and the Eye
Vitamin A is instrumental in maintaining healthy epithelial function, especially that of the mucous membranes of the eye and of the respiratory, urinary, and intestinal tracts. Ocular manifestations of vitamin A deficiency include dryness of the cornea and conjunctiva (xerosis) and poor nighttime vision (night blindness). Pathognomonic Bitot spots may also occur, which are composed of scaled-off keratin mixed with gas-forming bacteria generally located at the temporal limbus. In severe disease, corneal ulceration and melting may occur. Hypovitaminosis A should be considered as a differential in children who present with dry eye complaints (McAllister et al, 2013; Faustino et al, 2016; Hos and Cursiefen, 2014; Sommer, 1996).
For example: A 2-year-old boy presented with a history of recurrent hordeola affecting the upper and lower lids of both eyes for the past 12 months. He also had a history of crying without any expression of tears. Previous treatment consisted of lubrication and anti-allergic eye drops. His diet consisted of junk foods and sodas between meals and little intake of meat, dairy, fruits, or vegetables.
His slit lamp examination revealed mild punctate keratitis in both eyes and an epithelial defect in the right cornea; the rest of his ocular examination was unremarkable. His body weight matched the 50th percentile for his age and sex; however, his height was only in the 10th percentile.
Laboratory blood tests revealed low levels of iron and retinol (32.7μg/dl and 0.20mg/l; normal levels for children are 50 to 150μg/dl and 0.30 to 0.80mg/l, respectively). The patient’s results indicated that chronic hordeolum, keratoconjunctivitis sicca, growth retardation, and anemia were a consequence of his nutrient-limited diet. The patient’s diet was reoriented, and his pediatrician followed him closely until his clinical signs fully improved (Faustino et al, 2016).
Even though vitamin deficiency due to malnutrition is not common in the West, be sure to take a careful history for children who have dry eye symptoms—it may reveal a vitamin A-restricted diet. Severe ocular surface disease may result as a complication of vitamin A deficiency and may cause irreversible scarring and vision loss. If found, vitamin deficiency is correctable by dietary improvement. CLS
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Dr. Frogozo specializes in adult and pediatric specialty contact lenses. She is the director of the Contact Lens Institute of San Antonio and the owner of Alamo Eye Care in San Antonio, Texas. You can contact her at email@example.com.