A discussion of 61 cases of optic nerve coloboma.

Colobomata of the optic disc result from failure of closure of the most anterior portion of the optic stalk. Therefore the great majority of these defects are found at the six o'clock position in the region of the embryonic defect. The authors examined 61 patients with optic nerve coloboma from 1972 to 1983. The clinical data of these patients are given. It was remarkable that the optic nerve colobomata occurred in combination with the same systemic and 'midline'-defects that are often seen in combination with optic nerve hypoplasia.