ABSTRACT
The clinical classification of vitamin A deficiency is organized around assessment of the most reliable symptoms and signs of xerophthalmia. Listed in order of increasing severity, these include night blindness (XN), conjunctival xerosis with Bitot's spots (X1B), corneal ulceration and keratomalacia (X3), and, as a cumulative indicator of past potentially blinding disease, corneal scarring attributed to xerophthalmia (Table 1) (1,2).1t should be noted that the clinicohistopathology of these and all other stages of xerophthalmia has been critically reviewed elsewhere (1,3-5).
