This 55YO female presented with a unilateral optic nerve coloboma in her right eye. Vision was a remarkable 20/50 in her right eye and 20/30 in her normal left eye.
Learning Points:
Optic nerve colobomas can be a unilateral or bilateral condition, and, similar to other cavitary optic disc abnormalities, are caused by incomplete closure of the embryonic fissure. They can have an associated optic nerve pit, which was not seen in this patient. For a great review of cavitary optic nerve abnormalities, see Jain and Johnson, AJO 2014;158:423-435.
