Primary nonkeratinized epithelial ('conjunctival') orbital cysts.

The types of orbital cysts that are most familiar to ophthalmologists are epidermoid and dermoid cysts, both of which are lined by keratinized stratified squamous epithelium. We studied six patients who had orbital cysts lined by nonkeratinized epithelium that resembled normal conjunctiva. Compared with epidermoid and dermoid cysts, these primary nonkeratinized cysts tend to cause symptoms later in life, occur preferentially in the superonasal aspect of the orbit, and are less likely to be associated with underlying bony changes.