A congenital orbital defect with periorbital-dural tissue adhesion.

This case demonstrates a previously unreported congenital orbital deformity. The patient was born with a unilateral exophthalmos. The etiology of the defect was demonstrated by CT scan as a convex bowing of the right superomedial orbital wall behind the axis of the eye. At surgery, this convexity was revealed to be a small bony defect through which the periorbital tissue and dura mater adhered. This sort of orbital deformity, although subtle, must be considered in the differential diagnosis of congenital unilateral exophthalmos.