Cystic peripapillary staphyloma: a report of two cases.

Peripapillary staphyloma is a rare, nonhereditary, congenital anomaly in which an excavation surrounds the optic disk. We present 2 cases of peripapillary staphylomas resembling cystic cavities, both of which caused severe visual impairment. We propose the term cystic peripapillary staphyloma to describe this anomaly. The first case was associated with microphthalmia; the second, with encephalocele and Chiari malformation, an association that has not been previously described. We propose the term "cystic peripapillary staphyloma" to describe this anomaly.