- Xerophthalmia is a progressive eye disease caused by vitamin A deficiency, characterized by dryness of the conjunctiva and cornea due to the loss of normal tear production and mucous secretion.
- It is one of the most common preventable causes of childhood blindness, especially in developing countries. The condition encompasses a spectrum of ocular symptoms and signs, ranging from night blindness to severe corneal ulceration and perforation, culminating in irreversible blindness if left untreated. Xerophthalmia is both a sign of systemic nutritional deficiency and a critical public health concern, particularly in regions with widespread malnutrition.
- The underlying pathophysiology of xerophthalmia involves the lack of vitamin A, which is essential for maintaining the health of epithelial tissues, especially in the eye. Vitamin A supports the production of mucins by conjunctival goblet cells and maintains the integrity of epithelial cells. Its deficiency leads to keratinization and degeneration of the conjunctival and corneal epithelium. As a result, the eye’s surface becomes dry, rough, and susceptible to secondary infections and mechanical damage. Additionally, vitamin A is a precursor for rhodopsin, the visual pigment required for low-light (scotopic) vision, which is why nyctalopia (night blindness) is often the earliest symptom.
- Clinically, xerophthalmia is categorized by the World Health Organization (WHO) into a series of stages:
- XN – Night blindness
- X1A – Conjunctival xerosis (dry, lustreless conjunctiva)
- X1B – Bitot’s spots (foamy, keratinized patches on the conjunctiva)
- X2 – Corneal xerosis (dry, hazy cornea)
- X3A – Corneal ulceration/keratomalacia involving less than one-third of the corneal surface
- X3B – Corneal ulceration/keratomalacia involving more than one-third of the cornea
- XS – Corneal scarring
- XF – Xerophthalmic fundus (retinal changes due to long-standing deficiency)
- Xerophthalmia most commonly affects infants and young children, particularly those who are malnourished, weaned early, or suffer from recurrent infections such as measles or diarrhea, which increase vitamin A requirements and deplete stores. It also affects pregnant and lactating women with inadequate dietary intake. In adults, xerophthalmia can be a complication of chronic malabsorption disorders, alcoholism, or liver disease.
- Diagnosis is largely clinical, based on the characteristic appearance of the eye and patient history. Serum retinol levels may be measured to confirm deficiency but are often impractical in low-resource settings. The presence of night blindness and Bitot’s spots in a malnourished child is often sufficient to justify treatment.
- Treatment of xerophthalmia involves high-dose vitamin A supplementation according to WHO guidelines. A typical regimen for children includes 200,000 IU of vitamin A orally on day 1, another dose on day 2, and a third dose after 2 weeks. For infants under 6 months, smaller doses are recommended. In cases of corneal involvement or poor absorption, intramuscular administration may be necessary. Supportive care includes lubricating eye drops, antibiotic prophylaxis, and nutritional rehabilitation.
- Preventive strategies are crucial and include routine vitamin A supplementation, promotion of exclusive breastfeeding, dietary diversification, fortification of staple foods, and public health education. Global health initiatives have significantly reduced the prevalence of xerophthalmia, but it remains a challenge in areas with persistent food insecurity and poverty.
