Vitamin A Deficiency — Xerophthalmia

A 3-year-old girl from rural Uttar Pradesh presents with night blindness and Bitot's spots on slit-lamp examination. Her mother reports the child has been eating a diet predominantly of rice and lentils with minimal vegetables or animal products. Which investigation is most specific for confirming vitamin A deficiency?

A 5-year-old boy with a history of measles 2 weeks ago presents with corneal haziness and ulceration. Ophthalmologic examination reveals Bitot's spots and a milky cornea with loss of lustre. Which investigation would be most appropriate to assess the extent of corneal damage and guide management?

In a community health survey in rural Maharashtra, vitamin A deficiency is identified as a public health problem. Which is the most common presenting complaint that should alert clinicians to early xerophthalmia in children?

A 3-year-old child from rural Odisha presents with corneal scarring and blindness. On examination, the cornea is opaque and vascularized. The mother reports the child had night blindness 6 months ago, followed by conjunctival xerosis and a foamy patch on the nasal side. Which clinical feature best distinguishes corneal scarring (Stage X4) from corneal ulceration (Stage X3) in vitamin A deficiency?

A 5-year-old girl from a tribal region presents with corneal scarring and visual axis involvement due to vitamin A deficiency. The ophthalmologist needs to assess the extent of corneal damage and predict visual prognosis. Which investigation is most appropriate for this purpose?