Which vitamin deficiency causes keratomalacia and corneal scarring in children?

Explanation

## Vitamin A Deficiency and Ocular Manifestations **Key Point:** Vitamin A deficiency is the leading preventable cause of childhood blindness worldwide, particularly in developing countries including India. ### Ocular Manifestations in Order of Severity | Stage | Clinical Finding | Reversibility | |-------|------------------|----------------| | Early | Night blindness (nyctalopia) | Fully reversible | | Conjunctival xerosis | Dryness, Bitot's spots | Fully reversible | | Corneal xerosis | Haziness, loss of lustre | Fully reversible | | Corneal ulceration | Central melting | Partially reversible | | Keratomalacia | Corneal scarring, opacity | Irreversible blindness | **High-Yield:** Keratomalacia represents the terminal stage of xerophthalmia and results in permanent corneal scarring and irreversible blindness if not treated urgently with high-dose vitamin A supplementation. ### Systemic Manifestations - Follicular hyperkeratosis (phrynoderma) - Impaired immunity → increased susceptibility to infections (measles, diarrhea, pneumonia) - Growth retardation - Skin changes: dry, scaly appearance **Clinical Pearl:** In India, vitamin A deficiency remains endemic in certain regions. WHO recommends high-dose vitamin A supplementation (200,000 IU) for children with xerophthalmia or measles to prevent blindness. **Mnemonic:** VAD = **V**ision loss, **A**nti-infection impairment, **D**ry skin (phrynoderma) ### Why Other Options Are Wrong - **Vitamin D deficiency:** Causes rickets with skeletal deformities, not corneal scarring - **Vitamin E deficiency:** Causes neurological manifestations (spinocerebellar ataxia), not ocular disease - **Vitamin K deficiency:** Causes bleeding disorders, not eye disease