Xerophthalmia – Causes, Symptoms and Treatment

What Is Xerophthalmia?

Xerophthalmia (from the Greek xeros meaning dry and ophthalmos meaning eye) is a severe eye condition caused primarily by vitamin A deficiency. It is one of the leading preventable causes of blindness worldwide, particularly affecting children in low-income countries. The disease encompasses a spectrum of ocular damage ranging from mild night blindness to complete destruction of the cornea.

Causes

The primary cause of xerophthalmia is a prolonged and severe deficiency of vitamin A (retinol). Vitamin A is essential for the production of rhodopsin (the visual pigment in retinal rod cells) and for maintaining the integrity and regeneration of mucosal surfaces and ocular epithelium.

• Inadequate dietary intake: Malnutrition, especially in regions with low consumption of vitamin-A-rich foods such as liver, eggs, dairy products, carrots, sweet potatoes, and leafy greens.
• Malabsorption: Conditions such as celiac disease, inflammatory bowel disease, or cystic fibrosis can impair absorption of fat-soluble vitamins, including vitamin A.
• Increased requirements: Pregnancy, breastfeeding, and periods of rapid growth in children significantly increase the demand for vitamin A.
• Protein deficiency: Since vitamin A is transported in the blood bound to carrier proteins, protein malnutrition can also lead to functional vitamin A deficiency.

Symptoms

Symptoms of xerophthalmia develop gradually and are classified by the WHO into distinct stages based on severity:

• Night blindness (nyctalopia): The earliest and most common symptom – affected individuals have difficulty seeing in dim light or darkness.
• Conjunctival xerosis: Drying and thickening of the conjunctiva, causing the eye to appear dull and lustreless.
• Bitot spots: Foamy, whitish patches on the conjunctiva – a hallmark sign of vitamin A deficiency.
• Corneal xerosis: Dryness of the cornea leading to haziness and ulceration.
• Keratomalacia: Softening and necrosis of the cornea – the most severe stage, which can lead to corneal perforation and irreversible blindness.

Diagnosis

Xerophthalmia is primarily diagnosed through a clinical ophthalmologic examination that identifies characteristic signs such as night blindness, conjunctival changes, and corneal damage.

• Blood test: Measurement of serum retinol levels (normal range: 0.70–2.09 µmol/L); levels below 0.35 µmol/L indicate severe deficiency.
• Slit-lamp examination: Detailed assessment of the conjunctiva and cornea for disease-specific changes.
• Dark adaptation test: Assessment of visual function under low-light conditions to detect night blindness.

Treatment

Treatment depends on the severity of the condition and centers on high-dose vitamin A supplementation in accordance with WHO guidelines:

• Children under 1 year: 100,000 IU of vitamin A orally on day 1, day 2, and again after 2–4 weeks.
• Children over 1 year and adults: 200,000 IU of vitamin A orally following the same schedule.
• Pregnant women: Maximum dose of 10,000 IU per day or 25,000 IU per week (higher doses are teratogenic and must be avoided).
• Local treatment: In cases of corneal involvement, lubricating eye drops and antibiotic eye drops may be used to prevent secondary infections.
• Nutritional optimization: Long-term prevention through a balanced diet rich in vitamin A.

When corneal damage is identified early, it can often be reversed with prompt treatment. However, in the stage of keratomalacia, damage is frequently permanent.

Prevention

Xerophthalmia is largely preventable. International health organizations recommend the following strategies:

• Vitamin A supplementation programs targeting at-risk populations (children under 5 years, pregnant and breastfeeding women).
• Fortification of staple foods (e.g., cooking oil, flour, sugar) with vitamin A.
• Education about vitamin-A-rich foods such as liver, eggs, dairy products, carrots, mangoes, and leafy vegetables.
• Promotion of breastfeeding as a natural source of vitamin A for infants.

References

1. World Health Organization (WHO): Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO Global Database on Vitamin A Deficiency. Geneva, 2009.
2. Sommer A, West KP Jr.: Vitamin A Deficiency: Health, Survival, and Vision. Oxford University Press, 1996.
3. Bhutta ZA et al.: Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age. Cochrane Database of Systematic Reviews, 2017.