xerophthalmia

Xerophthalmia refers to the ocular signs and symptoms arising from vitamin A deficiency, including dryness of the conjunctiva and cornea that can progress to corneal ulcers, keratomalacia, and permanent blindness if not treated. It remains a major cause of preventable childhood blindness in areas with malnutrition and limited access to healthcare.

Etiology and epidemiology: Xerophthalmia results from inadequate vitamin A intake, malabsorption, or increased requirements. It commonly affects young children and pregnant or lactating women, especially in settings with food insecurity, infectious diseases, and poor nutrition.

Pathophysiology: Vitamin A supports the maintenance and function of the ocular surface, including goblet cells that produce mucin. Deficiency leads to squamous metaplasia and keratinization of the conjunctiva, reduced mucin production, and dryness. This can progress from conjunctival xerosis and Bitot spots to corneal xerosis and keratomalacia, with the risk of corneal scarring and vision loss.

Clinical features: Night blindness (nyctalopia) is often the first symptom, followed by conjunctival xerosis, Bitot spots, corneal xerosis, and keratomalacia. As the disease progresses, corneal ulcers and scarring can result in permanent visual impairment. Systemic signs of malnutrition may be present, such as growth faltering and increased susceptibility to infections.

Diagnosis: Diagnosis is clinical, based on history and characteristic ocular signs. Serum retinol levels are not reliable for individual diagnosis; assessment relies on ophthalmic examination and recognition of the typical progression of signs.

Management and prognosis: Treatment involves prompt high-dose vitamin A therapy according to age and local guidelines, along with measures to protect and lubricate the ocular surface, treat any infection, and correct nutritional deficiencies. Severe or persistent cases require ophthalmology referral. Prevention focuses on dietary improvement, vitamin A supplementation programs, and food fortification to reduce incidence and protect vision.