Xerophthalmia (vitamin A deficiency)


The term xerophthalmia covers all the ocular manifestations of vitamin A deficiency. Xerophthalmia can progress to irreversible blindness if left untreated.

In endemic areas, vitamin A deficiency and xerophthalmia affect mainly children (particularly those suffering from malnutrition or measles) and pregnant women.

Disorders due to vitamin A deficiency can be prevented by the routine administration of retinol.

Clinical features

– The first sign is hemeralopia (crepuscular blindness): the child cannot see in dim light, may bump into objects and/or show decreased mobility.

– Then, other signs appear gradually:
• Conjunctival xerosis: bulbar conjunctiva appears dry, dull, thick, wrinkled and insensitive
• Bitot’s spots: greyish foamy patches on the bulbar conjunctiva, usually in both eyes (specific sign, however not always present).
• Corneal xerosis: cornea appears dry and dull
• Corneal ulcerations
• Keratomalacia (the last and most severe sign of xerophthalmia): softening of the cornea, followed by perforation of the eyeball and blindness (extreme care must be taken during ophthalmic examination due to risk of rupturing cornea).

Treatment

Treat early symptoms to avoid the development of severe complications. Vision can be saved provided that ulcerations affect less than a third of the cornea and the pupil is spared. Even if deficiency has already led to keratomalacia and irreversible loss of sight, it is imperative to administer treatment, in order to save the other eye and the life of the patient.

– Retinol (vitamin A) PO
Regardless of the clinical stage:
Children from 6 to 12 months (or under 8 kg): 100 000 IU once daily on D1, D2 and D8
Children over 1 year (or over 8 kg): 200 000 IU once daily on D1, D2 and D8
Adults (except pregnant women): 200 000 IU once daily on D1, D2 and D8
Vitamin A deficiency is rare in breast fed infants under 6 months, if needed: 50 000 IU once daily on D1, D2 and D8.

In pregnant women, treatment varies according to the stage of illness:
• Hemeralopia or Bitot's spots: 10 000 IU once daily or 25 000 IU once weekly for at least 4 weeks. Do not exceed indicated doses (risk of foetal malformations).
• If the cornea is affected, risk of blindness outweighs teratogenic risk. Administer 200 000 IU once daily on D1, D2 and D8.

– Corneal lesions are a medical emergency. In addition to the immediate administration of retinol, treat or prevent secondary bacterial infections with 1% tetracycline eye ointment, one application 2 times daily (do not apply eye drops containing corticosteroids) and protect the eye with an eye-pad after each application.

Prevention

– Systematically administer retinol PO to children suffering from measles (one dose on D1 and D2).

–  In areas where vitamin A deficiency is common, routine supplementation of retinol PO:
Children under 6 months: 50 000 IU single dose
Children from 6 to 12 months: one dose of 100 000 IU every 4 to 6 months
Children from 1 to 5 years: one dose of 200 000 IU every 4 to 6 months
Mothers after giving birth: one dose of 200 000 IU immediately after delivery or within 8 weeks of delivery


Note: to avoid excessive dosage, record any doses administered on the health/ immunisation card and do not exceed indicated doses. Vitamin A overdose may cause raised intracranial pressure (bulging fontanelle in infants; headache, nausea, vomiting) and, in severe cases, impaired consciousness and convulsions. These adverse effects are transient; they require medical surveillance and symptomatic treatment if needed.