Optic disc coloboma

Optic disc coloboma is a rare defect of the optic nerve that causes moderate to severe visual field defects. It is a congenital anomaly in which there is a hole, or coloboma, in the inferior aspect of the optic disc. The issue stems from incomplete closure of the embryonic fissure while in utero. A varying amount of glial tissue typically fills the defect, manifesting as a white mass. The condition is often sporadic, meaning it is not inherited, but it can also occur as part of other conditions including CHARGE syndrome, Walker–Warburg syndrome, focal dermal hypoplasia, Aicardi syndrome, Goldenhar syndrome, and Schimmelpenning syndrome.

Historically, uncategorized optic disc anomalies have been described as colobomas, effectively turning the diagnosis into a wastebasket diagnosis. However, given the well-specified pathogenesis and presentation of coloboma, such unrecognized conditions are better described generically as dysplastic discs.