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 few years.