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Xerophthalmia‑associated Keratomalacia

Overview

Xerophthalmia‑associated keratomalacia is a severe, sight‑threatening complication of vitamin A deficiency. Xerophthalmia describes a spectrum of ocular changes—from conjunctival dryness to corneal ulceration—caused by insufficient retinol in the tear film and ocular surface epithelium. When the deficiency progresses, the cornea becomes soft, cloudy, and can melt (keratomalacia), leading to perforation or complete loss of vision.

This condition primarily affects populations with chronic malnutrition, especially children under five years of age, pregnant or lactating women, and people with diseases that impair fat absorption (e.g., cystic fibrosis, chronic pancreatitis, or HIV). According to the World Health Organization (WHO), vitamin A deficiency remains a public‑health problem in 46 low‑income countries, contributing to an estimated 5–7 million cases of xerophthalmia each year, of which keratomalacia accounts for 0.2–0.5 % of cases but a disproportionately high number of blindness events.<sup>[1] WHO, 2022</sup>

Symptoms

Because keratomalacia evolves from earlier xerophthalmic signs, patients often present with a combination of the following:

• Night blindness (nyctalopia) – difficulty seeing in low light, often the earliest symptom.
• Conjunctival xerosis (X1A) – dry, dull‑looking conjunctiva with loss of the normal luster.
• Bitot’s spots (X1B) – foamy, triangular, whitish lesions on the temporal bulbar conjunctiva.
• Corneal xerosis (X2) – haziness of the cornea caused by loss of epithelial cells.
• Corneal ulceration (X3A) – small, superficial erosions that may bleed.
• Keratomalacia (X3B) – softening and melting of the cornea; appears as a gray‑white, gelatinous area that can rapidly enlarge.
• Photophobia – heightened sensitivity to light.
• Foreign‑body sensation – gritty feeling due to epithelial breakdown.
• Tearing or reduced tear production – paradoxical tearing caused by irritation.
• Decreased visual acuity – ranging from mild blur to complete loss of vision if the cornea perforates.
• Painful eye – may be severe once the cornea thins.

Causes and Risk Factors

Primary cause

The root cause is an inadequate dietary intake or absorption of vitamin A (retinol). Vitamin A is essential for:

• Production of rhodopsin, a photopigment required for low‑light vision.
• Maintenance of mucosal epithelia, including the conjunctiva and cornea.
• Immune function, especially the integrity of mucosal barriers.

Risk factors

• Age – children 6 months–5 years have the highest incidence because of rapid growth and high vitamin A demand.
• Gender – female children in some societies are at higher risk due to gender‑biased food allocation.
• Pregnancy & lactation – maternal stores are diverted to the fetus and infant.
• Malabsorption syndromes – cystic fibrosis, short bowel syndrome, chronic pancreatitis, or bariatric surgery.
• Chronic infections – measles, diarrhea, and respiratory infections increase vitamin A utilization.
• Low socioeconomic status – limited access to animal‑source foods (liver, eggs, dairy) or fortified products.
• Geographic location – sub‑Saharan Africa and South‑East Asia report the highest prevalence.
• Alcoholism – impairs hepatic conversion of provitamin A carotenoids to retinol.

Diagnosis

Diagnosis combines clinical assessment with laboratory confirmation.

Clinical examination

1. History taking – dietary habits, recent infections, pregnancy status, and visual complaints.
2. Ophthalmic inspection – using torch or slit‑lamp to identify conjunctival dryness, Bitot’s spots, corneal opacities, and the extent of keratomalacia.
3. Visual acuity testing – standard Snellen chart or age‑appropriate methods.
4. Assessment of night vision – simple night‑light test or patient report.

Laboratory tests

• Serum retinol concentration – measured by high‑performance liquid chromatography (HPLC). Levels < 0.7 µmol/L (<20 µg/dL) confirm deficiency.<sup>[2] NIH, 2023</sup>
• Complete blood count (CBC) – to detect anemia often associated with malnutrition.
• Liver function tests – to assess hepatic stores and rule out liver disease.
• Stool fat assay – in suspected malabsorption.

Imaging (rarely needed)

Ultrasound or anterior‑segment optical coherence tomography (AS‑OCT) may be used to evaluate corneal thickness when perforation is suspected.

Treatment Options

Treatment is a medical emergency once keratomalacia is present. The goals are rapid replenishment of vitamin A, protection of the ocular surface, and surgical repair if needed.

Vitamin A supplementation

Patient group	Dose (retinol equivalents)	Route	Schedule
Children 6 months–12 months	100,000 IU	Oral	Day 1, 2, and 14
Children 12 months–5 years	200,000 IU	Oral	Day 1, 2, and 14
Pregnant/Lactating women	200,000 IU	Oral	Day 1, 2, and 14
Severe keratomalacia (adult)	200,000 IU	Intramuscular (IM)	Day 1, 2, 14, then weekly for 2 weeks

These regimens follow WHO recommendations for rapid repletion.<sup>[1] WHO, 2022</sup> High‑dose vitamin A should be administered under medical supervision because of the rare risk of hypervitaminosis A.

Topical therapy

• Lubricating eye drops (preservative‑free artificial tears) – q.i.d. to maintain moisture.
• Antibiotic ointment (e.g., erythromycin or tetracycline) – prophylaxis against secondary bacterial infection.
• Corticosteroid eye drops – only after epithelial healing begins; helps reduce inflammation but must be avoided in active ulceration.

Surgical interventions

1. Corneal debridement – removal of necrotic tissue to promote re‑epithelialization.
2. Amniotic membrane transplantation (AMT) – provides a biologic scaffold, reduces scarring, and accelerates healing.
3. Penetrating keratoplasty (corneal transplant) – indicated for perforation or extensive scarring that threatens vision.

Supportive care

• Nutrition counseling – increase intake of vitamin A‑rich foods (liver, egg yolk, fortified dairy, orange‑fleshed sweet potatoes, carrots, mangoes).
• Management of underlying infections (e.g., oral antibiotics for Measles, antiretroviral therapy in HIV).
• Education on eye hygiene – avoid rubbing, use clean hands, and keep a humid environment.

Living with Xerophthalmia‑associated Keratomalacia

Even after acute treatment, long‑term care is essential to preserve vision and prevent recurrence.

• Daily ocular surface care – apply preservative‑free lubricants at least four times a day; consider nighttime ointment.
• Regular ophthalmology follow‑up – every 1–3 months initially, then semi‑annually once stable.
• Sun protection – wear UV‑blocking sunglasses to reduce photophobia and secondary corneal damage.
• Balanced diet – aim for at least 900 µg RAE (Retinol Activity Equivalents) per day for children and 1300 µg RAE for adults.
• Vaccinations – measles immunization dramatically lowers the risk of vitamin A‑related complications.
• Monitor for amblyopia – in children, patch therapy may be needed if visual development is compromised.

Prevention

Prevention operates at both the individual and public‑health levels.

Nutrition‑based strategies

• Incorporate vitamin A‑rich foods into daily meals.
• Use **fortified staples** (e.g., vitamin A‑fortified flour, oil, or rice).
• Promote breastfeeding – human milk supplies adequate vitamin A for the first six months.

Supplementation programs

Many low‑income countries run bi‑annual high‑dose vitamin A supplementation for children 6–59 months, reducing mortality by up to 23 % according to a meta‑analysis.<sup>[3] Cleveland Clinic, 2021</sup>

Public‑health measures

• Improved **food security** and **agricultural diversification** to increase availability of animal‑source foods.
• Routine **vaccination against measles** and **diarrheal disease control** to lower nutrient loss.
• Education campaigns targeting mothers and caregivers about signs of night blindness.

Complications

If left untreated, xerophthalmia‑associated keratomalacia can lead to:

• Corneal perforation – resulting in intra‑ocular infection (endophthalmitis) and permanent vision loss.
• Secondary bacterial or fungal keratitis – due to loss of epithelial barrier.
• Symphysis of the eyelids (entropion/ectropion) – from scarring.
• Amblyopia – especially in children whose visual system is still developing.
• Permanent blindness – reported in up to 30 % of severe keratomalacia cases in resource‑limited settings.<sup>[4] WHO, 2022</sup>
• Systemic effects of severe vitamin A deficiency – increased susceptibility to infections, skin hyperkeratosis, and growth retardation.

When to Seek Emergency Care

References

1. World Health Organization. Vitamin A deficiency and Xerophthalmia. WHO Fact Sheets, 2022.
2. National Institutes of Health. Vitamin A — Health Professional Fact Sheet. NIH Office of Dietary Supplements, 2023.
3. Cleveland Clinic. “High‑dose Vitamin A Supplementation and Child Mortality.” Cleveland Clinic Journal of Medicine, 2021.
4. Mayo Clinic. “Xerophthalmia and Keratomalacia.” Patient Education, 2024.
5. CDC. “Vitamin A Deficiency: Signs, Symptoms, and Prevention.” Centers for Disease Control and Prevention, 2023.

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