In which stage, corneal ulcer involving 1/2 of Corneal surface seen in WHO classification of vitamin A deficiency
WHO classification of Vitamin A deficiency:
I Primary changes
X1A ⇒ Conjunctival xerosis
X1B ⇒ Bitot's spots
X2 ⇒ Corneal xerosis
X3A ⇒ Corneal ulcer < 1/3 rd of corneal surface
X3B ⇒ Corneal ulcer > 1/3rd of corneal surface.
II Secondary changes
XN ⇒ Night blindness
XF ⇒ Xeropthalmic fundus
XS ⇒ Xerophthalmia - related corneal Scar
Stage 2
Stage 3A
Stage 3B
Stage 4