Desiccation of the conjunctiva due to a vitamin A deficiency.
Due to the high general standard of nutrition, this disorder
isvery rare in the developed world. However, it is one of the most frequent
causes of blindness in developing countries.
Vitamin A deficiency results in keratinization of the
superficialepithelial cells of the eye. Degeneration of the goblet cells causes
the surface of the conjunctiva to lose it luster (Fig. 4.5a). The keratinized epithelial cells die and are swept into the
palpebral fissure by blinking, where they accumu-late and create characteristic
white Bitot’s spots (Fig. 4.5b).
Xerosis bacteria frequently proliferate.
The changes disappear after local and systemicvitamin A substitution.
Without vitamin A substitution, the disorder will lead to blindness within a